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This is a work in progress. Step 1 is to get as many references into this book as possible. These references may be better placed in wikisource, but they are in this book for now. Only trusted references are used. That does not make these references true, it just means that they were made during the period of time when the events they describe occurred. modern references that refer to events that occurred 50 to 100 years ago are considered secondary and less trustworthy.

Step 2 will be to pull information from these references and try to create a timeline of the events.

Introduction
One day while feeding the Elephant Child, I was looking into a claim from a coworker (whose family owned a small farm) that ethanol from corn was actually an energy sink. That lead me to cellulostic ethanol, who's pie in the sky claims I had been reading about for years, then to the history of cellulostic ethanol.

There are many references to cellulostic ethanol that seem to have no evidence. After digging into some of these claims, I had amassed enough data that I decided to create this book so that the best of these references could be used to create a history of cellulostic ethanol.

Timeline
1855 was founded in wood fiber under the direction of chemist Pelouze in Paris a factory for the manufacture of alcohol. But she did not seem to have long existed; because only once (1859), we find a reference by a publish Pelouze treatise (Dingl. Journ. 150, 394), which brings nothing really new. 1867 published experiments of Payen on Cellulosc. You also assume the pulp representation by should be obtained from the lignin-containing black liquor as a byproduct alcohol. Dr. J. MattheuB wants to win fermentable peat dextrose. On 2/12 1894 it patented (DRP 92079) in Germany the chemist Simonsen from Christiania a method for rapid saccharification of cellulosic materials with the help of 0.4-0.8% strength acids at 7 Atm. Pressures and above. The process should be completed in 10-30 minutes. Simonsen won from 1 kg wood 60g Alcohol, ie an over earlier specifications rocht modest yield.
 * 1819 - Henri Bràconnot is the first to create sugars from cellulose. Bràconnot published a method of converting woody fiber into fermentable sugar.  Published in Annales de Chimie et de Physique on 4 novembre 1819 (Annals of Chemistry and Physics 4/11/1898).  Bràconnot claimed to create more sugar than wood.
 * 1854 - Arnould publishes a treatise in Dingl. Journ. (134, 219). He claims to be able to transform 80-90% or certain woods into soluble product.
 * 1855 - Melsens writes 1855 in "Genie Industriel" about reducing the concentration of the applied sulfuric acid to 3-5% and shall follow the procedures mainly on manufacturing residues. He is the first who worked in an autoclave and temperatures up to 180 ° applying an end.
 * 1855 - Commercial plant in Paris under direction of the chemist Pelouze to produce alcohol from wood. This plant does not appear to have existed for many years.
 * 1867 Payen claimed to have obtained alcohol from the lignin contained in the wastes of the manufacture of paper, and Matthews claimed to have obtained fermentable dextrose from peat.
 * 1894 - The Norwegian chemist Simonsen patented, in Germany, a process for the rapid saccharification of substances containing cellulose by treatment with weak acids (4/10 to 8/10 per cent) under a pressure of 7 atmospheres or more. Simonsen claimed yields of 6% (60 gramms of alcohol per kg of wood)
 * 1898 - In 1898 Simonsen published the results of experiments on the influence of pressure, time, and the quantities of water and acid employed in the inversion of substances containing cellulose. Simonsen claimed a 5% yield

In the spring of 1898 a longer work of the above-mentioned inventor in Germany became known. She was rewarded by the polytechnic clubs to Christiania with a gold medal and through this magazine (II, 195 [1898])

After successful experiments in a test plant erected by Classen in Aachen On February 15, 1899 the Dr. Alexander Classen from Aachen was the first patent on a Holzverzuckerungsverfahren issued (DRP 118 868). It is strongly pressing a mixture of sawdust and sulfuric acid by 57 ° Be. The mass is heated by itself, is then crushed and boiled with water. 1900 - Classen gets three more patents This is followed by three patents of 12 /. 5 1900 (D. R. P. 118 542, 118 543, 118 544). The first is that you heat the wood substances with hydrogen chloride in an autoclave and then importing sulfuric acid to form sulfuric acid. The second patent will the yield of sugar increased due to heating the raw material with sulfur dioxide and then initiates the formation of sulfuric acid chloride. The third patent is that the mixture is heated until the sawdust with sulphurous acid and introduced to their conversion into sulfuric air or oxygen.
 * 1890's - Classen experiments.
 * 1898 - Classen erects pilot plant in Aachen [unverified]
 * 1899 - Classen gets patent


 * 1901 Gentzen and Roth patented the employment of ozone for the purpose of converting lignin into fermentable sugar and destroying substances which prevent fermentation.


 * 1900-1903 Lignum Inversion Company purchases patent rights and erects experimental plant at Highland Park. Illinois [Unknown exactly when this plant was built]

The following is from The Iron Age 1903

For three months the factory at Highland Park was placed under the direct control of Dr. John H. Long, Professor of Chemistry in the Northwestern University, Chicago, and president of the American Chemical Association.

Professor Long states that he had no question that the product is really as good as grain alcohol.

After professor Long's retirement, management passed into the hands of Otto Sjostrom, a German chemist and assistant to Professor Classen, under whose direction much of the work at the original plant erected at Aix-la-Chapelle was carried on.

The Lignum Inversion Company of Chicago, with a capital stock of $110,000, is the organization which has secured the Classen patents in the United States, and under whose direction all work in this country thus far has been accomplished. J. M. Ewen of Chicago is president, and J. K. George of London managing director. A number of wealthy and influential business men of Chicago, Pittsburgh and New York have become interested in the company, as well as large saw mill interests in Mississippi. It is understood that the Lignum Inversion Company is soon to be converted into the Classen Lignum Company, with a capital stock of $2,500,000, and arrangements will be shortly completed for the erection of a plant for the manufacture of alcohol by the Classen process, with a capacity of 100 tons per day, at a point in the South, and a contract has been signed for the erection of another plant of equal capacity in Northern Michigan.
 * 1903 Classen Lignum Company.

In 1905 (8 / G.) Was the Kaufmann Arno natives of Vienna in England granted a patent for the presentation of sugar from cellulosic materials.
 * 1905 - In 1905 Boernen obtained an English patent for a process employing 5 per cent solutions of caustic alkalies at about 90 deg. P., and boiling the liquid after the unaffected residue of the wood has been removed by filtration.


 * 190? - Classen Lignum Company erects full scale plant in Hattiesburg, Miss. at a cost of $250,000. This plant never functions successfully.

The following is from Scientific American Supplement 1910 The results were so satisfactory that a. larger plant on a commercial scale was erected at Hattiesburg, Miss. The plant built in the United States, which is reported to have cost for building and working for a year about $250,000, has not been used for some time.

Two chemical engineers, Malcolm F. Ewen and G. H. Tomlinson, who were associated with the Classen process, both in Germany and the United States, finding the original process unlikely to prove a commercial success, obtained substantial financial aid from a Chicago engineer, Mr. J. M. Ewen, and in 1904 began experimenting along new lines to overcome the difficulties which prevented the old process from being a success.

This process, by the courtesy of the patentees, l was enabled to study in June, 1909, at Chicago Heights, about 20 miles from the city of Chicago. The plant was erected by the Wood Waste Products Company. now called the Standard Alcohol Company, which has control of the Ewen-Tomlinson patents. This experimental plant was composed of units of commercial capacity, and was set up in workshops in the grounds of a large machinery manufactory.

In the plant now being built for the Du Pont Powder Company at Georgetown, S. C., it is probable that there will be three or four converters, egg-shaped or spherical, and capable of taking four to five tons at one charge.

In France there is in operation another process for the manufacture of ethyl alcohol from wood waste. I know nothing of this process beyond an account of it which appeared in the General Electric Review of September, 1909, by G. U. Borde.

A plant is being erected to use this French process at Hadlock, Wash., and another is proposed for some place in Ontario.

1819
Braconnot  Annales de Chimie et de Physique 12: 172-95 Excerpt English translation from Google Translate

Annales de Chimie et de Physique (French)
Mémorie sur la conversion du corps ligneux en gomme, en sucre, et en acide d'une nature particuliére, par le moyen de l'acide sulfurique; conversion de la meme substance ligneuse en ulmine par la potasse

Par Henri Bràconnot.

(Lu à la Société royale académique des Sciences, etc. de Nancy, le 4 novembre 1819.)

Les anciens chimistes se sont contentés de répéter que l'action de l'acide sulfurique concentré sur les substances végétales se bornait à les charbonner. Parmi les modernes, M. Berthollet a pensé que l'hydrogène de la substance végétale s'unit à l'oxigène de l'acide sulfurique, et qu'en formant ainsi de l'eau et de l'acide sulfureux , le principe charbonneux se sépare et se précipite. MM. Fourcroy et Vauquelin cherchèrent ensuite à répandre plus de clarté sur ce phénomène (1). Ils admirent qu'il ne se dégage point d'acide sulfureux, et donnèrent une théorie ingénieuse , mais qui ne semble pas établie sur des preuves bien rigoureuses.

En examinant les changemens remarquables que les composés organiques subissent par l'action de l'acide sulfurique, j'ai été conduit à des résultats bien différens de ceux obtenus par ces illustres chimistes, et je me persuade que les principaux faits que je vais présenter contribueront à jeter une vive lumière sur plusieurs phé nomènes de la végétation, et pourront trouver d'utiles applications aux arts.

Action de l'acide sulfurique sur la sciure de bois de charme.

20 grammes de sciure de charme bien desséchée on été arrosés à froid avec de l'acide sulfurique du commerce (I) ; on a agité le mélange avec un tube de verre; il s'est fortement échauffé, et , conformément à la théorie de M. Berthollet , le gaz acide sulfureux s'est dégagé avec impétuosité ; la sciure est devenue noire et semblait être à l'état de charbon ; mais elle n'en avait que l'apparence. J'ai versé sur le tout une certaine quantité d'eau; j'en ai séparé la poudre noire, qui, desséchée et ensuite projetée dans le feu, a brûlé avec flamme. Elle ne colorait pas sensiblement l'eau froide; mais elle a communiqué à l'eau bouillante et aux dissolutions alcalines une couleur brune foncée. Elle était à-peu-près dans le même, état que l'aurait été la sciure exposée pendant quelques années à l'air et à l'humidité. La liqueur acide, qui était presque incolore comme de l'eau, après avoir été saturée avec du carbonate de chaux , a fourni par l'évaporation une matière gommeuse jaunâtre dans la dissolution de laquelle le sous-acétate de plomb a formé un magma blanc fort abondant. Cette matière gommeuse, traitée par l'acide sulfurique affaibli , a fourni de l'acide acétique , et a précipité du sulfate de chaux.

J'ai répété l'expérience avec 16 grammes de sciure; mais, au lieu de verser l'acide sulfurique sur toute cette quantité, je l'ai broyé par petites portions, en ajoutant peu à peu l'acide : malgré ces précautions, il s'est encore; dégagé de l'acide sulfureux; mais j'ai obtenu un mucilage très-épais, tenace, que j'ai délayé dans une certaine quantité d'eau, et j'ai filtré à travers un linge; il est resté une matière insoluble noirâtre, du poids de 5 grammes, à-peu-près semblable à celle de l'expérience précédente ; la liqueur acide, saturée par la craie, puis évaporée, ai fourni près de 10 grammes d'une gomme d'un brun rougeâtre. Comme MM. Fourcroy et Vauquelin disent, dans leur Mémoire, que les substances végétales ne décomposent pas à froid l'acide sulfurique, j'ai pensé que ce dégagement d'acide sulfureux devait au moins être fort rare; en conséquence j'abandonnai aussitôt la sciure de charme.

Pour mieux apprécier les résultats, je me disposais à préparer la matière ligneuse ; mais trouvant de la difficulté pour l'amener à un état de pureté parfaite , je trouvai beaucoup plus commode de me servir de chiffons de toile de chanvre que l'on trouve par-tout , -et que l'on peut considérer comme une matière ligneuse pure : au reste, toute autre espèce de corps ligneux aurait pu donner des résultats analogues.

section de T acide sulfurique sur la toile de chanvre usée.

25 grammes de toile de chanvre, coupée en petits morceaux, ont perdu, à la chaleur, un gramme d'eau hygrométrique. J'ai mis cette toile dans un mortier de verre, et l'ai arrosée à plusieurs reprises avec 34 grammes d'acide sulfurique, en ayant soin d'agiter continuellement le mélange avec une forte baguette de verre, pour que l'acide pénètre aussi uniformément que possible toutes les parties de la toile , et de mettre un intervalle assez long entre chaque addition d'acide pour que la chaleur qui se développe soit entièrement dissipée : il ne s'est point dégagé le moindre indice d'acide sulfureux. Un quart d'heure apres que le mélange a été fait, je l'ai broyé avec un pilon de verre; tout le tissu du linge a disparu, et il en est résulté une masse mucilagineuse extrêmement tenace , poissante , homogène- et peu colorée, que j'ai abandonnée pendant vingt-quatre beures. J'indique ces précautions pour obtenir de plus beaux produits; car, de quelque manière qu'orj s'y prenne, il ne se dégage point d'acide sulfureux , et il ne se dépose aucun indice de matière d'apparence charbonneuse. Cette masse mucilagineuse s'est entièrement dissoute dans l'eau, à l'exception d'une matière amiliforme, du poids de 2,5 grammes après sa dessiccation , et qui n'était qu'une portion du linge qui n'avait pas éprouvé une profonde altération de la part de l'acide sulfurique. Cette masse mucilagineuse, ainsi étendue d'eau, a été saturée avec de la craie ; filtrée à travers un linge, elle était claire et n'avait qu'une trèslégère couleur ambrée : après avoir eu soin de bien laver le filtre et d'exprimer fortement le sulfate de chaux, j'ai réuni les liqueurs et les ai fait évaporer en consistance d'un sirop qui était moins coloré que celui de capillaire  : il s'est encore séparé une petite quantité de sulfate de chaux par Je refroidissement. J'ai continué l'évaporation avec ménagement jusqu'à siccité, et j'ai obtenu une gomme transparente , peu colorée : elle pesait 26,2 grammes qui ont été fournis par 21, 5 grammes de toile , déduction faite d'un gramme d'humidité, plus 2,5 grammes de matière ligneuse amiliforme. Je ne dois pas omettre que le sulfate de chaux résultant de la saturation, quoique bien lavé, retenait encore de la matière végétale ; car, exposé au feu, il a pris une couleur brunâtre et a répandu une odeur d'acide sulfureux- Comme il était à présumer que cette augmentation remarquable de poids ne pouvait être due qu'à une fixation des élémens de l'eau ou de l'acide sulfurique, pour chercher à vérifier si ce soupçon était fondé, j'ai fait dissoudre dans l'eau 5 grammes de cette gomme artificielle ; j'y ai ajouté de l'acide oxalique pour précipiter la chaux qu'elle retenait en combinaison , et qui peut aussi en être précipitée par l'acide sulfurique. Le précipité d'oxalate de chaux recueilli et chauffé fortement, a laissé o,28 grammes de chaux.

....

Annals of Chemistry and Physics (English)
Memory on the conversion of timber body rubber, sugar, and acid of a specific nature, by the sulfuric acid means; converting the same woody substance ulmine by potash

By Henri Bràconnot.

(Read in the Royal Society of Science Education, etc. Nancy, November 4, 1819.)

The older chemists were content to repeat that the action of concentrated sulfuric acid on plant substances was limited to the charcoal. Among the moderns, Mr. Berthollet thought the hydrogen plant substance combines with the oxygen of the sulfuric acid, and that by forming water and sulfur acid, carbonaceous ingredient separates and precipitates. MM. Fourcroy and Vauquelin then sought to spread more clarity on this phenomenon (1). They admitted that it emanates sulphurous acid point and gave an ingenious theory, but that does not seem well established on rigorous evidence.

By examining the remarkable changes that organic compounds undergo the action of sulfuric acid, I was led to much different results from those obtained by these illustrious chemists, and I am convinced that the main facts that I present help to throw much light on several phenomena of vegetation, and may find useful applications to the arts. The action of sulfuric acid on the charm sawdust.

20 grams of dried well boutique sawdust is drenched with cold sulfuric acid of commerce (I); by stirring the mixture with a glass tube; it is strongly heated, and, according to Mr. Berthollet theory, sulfurous acid gas was evolved with impetuosity; sawdust turned black and seemed to coal state; but she had that appearance. I poured over all a certain amount of water; I have separate black powder, which, dried and then thrown into the fire, burned with flame. 20 grams of dried well boutique sawdust is drenched with cold sulfuric acid of commerce (I); by stirring the mixture with a glass tube; it is strongly heated, and, according to Mr. Berthollet theory, sulfurous acid gas was evolved with impetuosity; sawdust turned black and seemed to coal state; but she had that appearance. I poured over all a certain amount of water; I have separate black powder, which, dried and then thrown into the fire, burned with flame. It did not stain substantially cold water; but she communicated with boiling water and alkaline solutions dark brown. She was nearly in the same state that was sawdust exposed for several years to air and moisture. The acidic liquor, which was almost colorless like water after being saturated with calcium carbonate, provided by evaporation a yellowish gummy material in the solution from which lead acetate formed under a white magma very abundant. This gummy material, treated with sulfuric acid weakened, provided of acetic acid, and a precipitate of calcium sulphate.

I repeated the experiment with 16 grams of sawdust; but, instead of pouring sulfuric acid on the whole amount, I crushed in small portions, adding gradually Acid: despite these precautions, he again; Cloudy sulfurous acid; but I got a very thick mucilage, tenacious, I stirred into a certain amount of water, and I filtered through a cloth; he remained a black insoluble material, the weight of 5 grams, with nearly similar to that of previous experience; liquor acid, saturated with chalk, and then evaporated, have provided nearly 10 grams of a reddish brown gum. As MM. Fourcroy and Vauquelin say, in their memory, that plant substances do not break in cold sulfuric acid, I thought that this disengagement of sulphurous acid should at least be very rare; accordingly I left immediately the charm of sawdust.

To better appreciate the results, I was preparing to prepare timber; but finding it difficult to bring it to a state of perfect purity, I found more comfortable to make use of hemp cloth rags found every where-and that can be considered as a matter pure wood: besides, any other kind of timber body could have similar results.

Section on sulphuric acid on worn hemp cloth.

25 grams of hemp cloth, cut into small pieces, lost, heat, a humidity gram water. I put this picture in a glass mortar, and have watered several times with 34 grams of sulfuric acid, being careful to continuously stir the mixture with a strong glass rod, so that the acid penetrates as evenly as possible all parts of the canvas, and set a long interval between each addition of acid to the heat that develops either entirely dissipated: it is is not clear any hint of sulfurous acid. Fifteen minutes after the mixture has been done, I crushed with a glass pestle; any tissue machine is gone, and this resulted in a mucilaginous mass extremely tenacious, tackifying, between homogeneous and slightly colored, which I abandoned for twenty-four o'clock in. I point these precautions for more beautiful products; because in some way it qu'orj take it emerges sulfurous acid point and it settles any evidence relating to anthrax appearance. This mucilaginous mass is fully dissolved in water, with the exception of a amiliforme material, weight 2.5 grams after drying, and which was only a portion of the cloth that had not experienced a profound alteration of the part of the sulfuric acid. This mucilaginous mass and body of water was saturated with chalk; filtered through a machine, it was clear and had only trèslégère amber: having taken care to wash the filter and strongly express the sulphate of lime, I met liqueurs and did evaporate in a syrup which was less colored than that of capillary: it is still separated a small amount of calcium sulphate I by cooling. I continued evaporate gently to dryness, and I got a clear gum, colorful little: she weighed 26.2 grams, which were provided by 21, 5 grams of fabric, less than one gram humidity, plus 2.5 grams of amiliforme timber. I must not omit that the calcium sulphate resulting from saturation, although well washed, still holding the plant material; because, exposed to fire, he took a brownish color and spread a sulfurous acid smell as it was presumed that this remarkable weight increase could be due to a setting of the water or the elements sulfuric acid, to try to verify this suspicion was based, I dissolve in water 5 grams of the artificial gum; I added oxalic acid to precipitate the lime she was holding in combination, and can also be precipitated by sulfuric acid. The lime oxalate precipitate collected and heated strongly, left 0.28 grams of lime.

....

THE IRON AGE. September 17, 1903
From THE IRON AGE. This is a bound book containing a collection of articles. This may be a collection of magazine articles. The page is labeled 12, but starts on PDF page 797. There is no author attributed. The book if from the University of Michigan and was scanned by Google.

The Manufacture of Ethyl Alcohol from Wood.

The manufacture of ethyl alcohol from wood is one of the latest achievements of science. To realize the significance of this announcement, from a chemical standpoint, and to appreciate the importance of the discovery to the alcohol and lumber manufacturing[sic] industries, it is only necessary to keep clearly in mind the distinction between ethyl or grain alcohol —as it is known in commerce— and methyl alcohol, or wood spirits.

Heretofore ethyl alcohol, C2H6O, has been manufactured in this country almost entirely from corn, and in European Countries, especially in Germany, from beets and potatoes. The only alcohol that heretofore has been Obtained from Wood On a commercial basis has been methyl alcohol, CH4O, as a by-product in the manufacture of charcoal by the retort process. Plants of this character have been installed at nearly all of the modernly equipped charcoal iron blast furnaces in the United

[IMAGE] Fig. 1.--Rotary Digester.

States, acetate of lime and tar, with methyl alcohol, being the by-products secured.

Methyl alcohol, or the present wood alcohol of Commerce, is consumed principally in the arts, its physical properties rendering it unfit to be used as a basis for “blended goods,” which are consumed as beverages. The muddy color, offensive odor and virulent toxic properties of methyl alcohol preclude it, even when rectified, from entering the wide commercial field open to ethyl alcohol.

From the theoretical standpoint, of course, it is and has been possible to make ethyl alcohol from wood, and it has been produced in the laboratory by a number of eminent chemists. But up to within the past year no method had been devised for the manufacture of ethyl alcohol from wood on a commercial basis, all laboratory processes being too expensive. It has been the conviction of chemists, however, that eventually the secret would be found.

Heretofore chemists who have worked along this line have used sulphuric acid to convert the cellulose in wood into sugar, but to neutralize the effects of, or to recover, the acid from the sugar solution has not been possible economically. In order to overcome this difficulty Alexand Classen of Aachen, Germany, conceived the idea of using sulphurous instead of sulphuric acid—sulphurous acid being a gas at ordinary temperature and presSure, and therefore more amenable to treatment. The result, it seems, has been the development of the Classen process for the Successful manufacture, on an economical Commercial basis, of ethyl alcohol from wood. Alexander Classen is an eminent chemist of Europe, professor of chemistry in the Aachen Polytechnic School, and a privy State counselor of the German Empire.

Source of Raw Material Supply. How to dispose of saw mill refuse has been one of the most serious problems presented to manufacturing lumbermen for many years. In some mills the sawdust, with slabs, edgings and trimmings, is used as fuel under the boilers. But even so, the largest mills find difficulty in disposing of the waste product. There is a wide variation in the amount of this refuse, but at modern mills of large capacity it is estimated to be within 12 to 15 percent. of the actual contents of the log.

Some lumbermen have actually constructed plants in which to burn or otherwise dispose of the sawdust. It will be seen from this that the refuse, which may now become a source of revenue, at the present day is a cause of annoyance and expense to the saw mills, and Such is the magnitude of the mill industry that there is an abundance of material which may be utilized in the manufacture of alcohol for years and years to come. It is estimated that there are between 25,000 and 26,000 saw mills in the United States, varying in size, and each cutting from 5000 up to 600,000 feet of lumber per day, and

[IMAGE] Fig. 2.--Exhaustion Battery.

that the waste is, on an average, 10 to 15 per cent. It is possible, therefore, to establish plants for the manufacture of alcohol from wood at mills where a supply of from 100 to 600 tons of the raw material may be obtained per day, it being estimated that 1000 feet of waste will weigh 1 ton. There is a single mill in Mississippi which cuts 600, 000 feet per day and another 300,000 feet per day. Anther Southern company, running five to six mills, cut in the aggregate 500,000 feet daily.

Yield and Cost of Manufacture. From the experiments which have been made in this country, on a semicommercial[sic] Scale, it has been determined that one ton of wood of 2240 pounds will yield from 24% to 27 gallons of absolute alcohol, or 49 to 54 proof gallons, at a cost of 13 cents per absolute gallon. With the perfecting of the process, and especially with the employment of improved mechanical methods, it is confidently expected that the cost will be reduced to 7 cents per absolute gallon. The cost of manufacturing alcohol from grain is estimated to be about 20 cents per absolute gallon, based upon corn at 30 cents per bushel. At present the cost is considerably more, as the market price of corn has risen to 50 cents and over. On the average 4 3/4 proof gallons of alcohol are obtained from a bushel of corn.

It has also been determined that the same quantity of alcohol is obtained from a ton of wood in this country as is obtained from a ton of potatoes in Germany, but the alcohol obtained from wood is said to be of much better quality than that derived from potatoes. The cost of potatoes in Germany is from $6.50 to $8 per ton, while the cost of sawdust in the United States is but from 25 to 50 cents per ton.

Charcoal and Other By-Products. One important feature in the manufacture of ethyl alcohol from wood by the Classen process is that after the cellulose has been converted into sugar and the Sugar extracted from the wood the tailings may be pressed into briquettes without a binding agent, while wood alcohol, wood tar and acetate of lime may be obtained from the wood residue in the process of making charcoal, just as though no ethyl alcohol had been manufactured. This is especially important and interesting to charcoal blast furnaces, and may be worthy of special consideration. Experiments show that about 75 per cent of the original weight of the wool may be converted into charcoal briquettes. The chemical composition of the charcoal thus produced is given by Otto Hehner, an eminent chemist of London, who has verified the figures made by Professor Classen, as follows: Carbon, 80 per cent.; hydrogen, 1.04 per cent. ; nitrogen, 0.32 per cent. ; oxygen, 8.34

[IMAGE] Fig. 3.—Acid Room and Apparatus.

percent. ; sulphur, 0.01 per cent. ; moisture, 9.05 per cent. ; ash, 0.47 percent.

Experimental Plant at Highland Park. Illinois. The Lignum Inversion Company, who have purchased the right to manufacture ethyl alcohol in the United States under the Classen patent, have established an experimental plant at Highland Park, near Chicago, which has been in operation about eight months. This plant, of which the essential features are shown in the accompanying illustrations, is necessarily crude from a mechanical and engineering standpoint, but, even with its inefficient machinery, results have been obtained which are highly satisfactory. For three months the factory at Highland Park was placed under the direct control of Dr. John H. Long, Professor of Chemistry in the Northwestern University, Chicago, and president of the American Chemical Association. In making his report at the end of this period Professor Long states that he made the tests rigid, to be certain that the product is really as good as grain alcohol, of which he had no question. In his report Professor Long states that the process is based on simple and thoroughly rational scientific principles, and has been well worked out by Professor Classen. He considers that the value of the process depends on three factors: 1. It is extremely simple in theory and operation. 2, The raw material used is cheap and abundant, and 3, it infringes on no previous patents, since the method is quite original with Classen. All previous attempts to obtain fermentable sugar from wood have been failures in practice.

The Process in Details. In the process of manufacturing ethyl alcohol from wood there are four stages: 1, The conversion of the Cellulose in the wood into sugar. 2, The extraction of the Sugar from the sawdust. 3, The fermentation of the Sugar; and 4, the distillation of the alcohol.

The equipment consists of the necessary tanks and other apparatus for the manufacture of the sulphurous acid gas and the generation of steam ; a tank in which the acid is under pressure; a rotary digester, in which the Sawdust is treated with the combined acid and steam; an exhaustion battery for the extraction of the Sugar from the Sawdust; tubs in which the fermentation is carried on, and last, an ordinary still. The sugar solution is passed through the exhaustion battery by means of a rotary pump. The simple machinery is driven by means of a 4% horse-power steam engine.

The labor cost is light, as but two men are required throughout the entire process, one being the chemist and the other an unskilled laborer. It should be remembered, however, that the distillation process, as in all other cases where alcohol is manufactured, is necessarily under

[IMAGE] Fig. 4.—Fermentation Room.

government supervision, the manufacturers, of course, bearing the expense incurred through the internal revenue department.

The sawdust which is to be treated is placed in a lead lined iron cylinder, Fig. 1, called the digester, capable of revolving upon its axis. The cylinder is surrounded by a steam jacket for the application of heat. The sawdust is moistened with a 3 percent solution of sulphurous acid, one-third the weight of the wood, the acid and steam being introduced through pipes conveyed from the acid room. The temperature is raised to about 145 degrees C. under a pressure of about 100 pounds to the square inch, and the digester slowly revolved. As the temperature is raised the gas is liberated from the steam and penetrates the wood, converting the cellulose into sugar. At the expiration of about 90 minutes the process is complete, when fully 85 percent of the sulphurous acid is recovered with the exhaust steam. By this treatment the sawdust shrinks to about two-thirds of its original bulk and presents a nearly dry mass, having the appearance of coarse ground roasted coffee. The contents of the digester are discharged into a receptacle beneath the cylinder, and subsequently conveyed to the exhaustion battery, Fig. 2, in which the sugar is washed from the Sawdust.

The exhaustion battery consists of a series of tubs or Vats, each vat at the experimental plant having a capacity of 36 gallons. Of course these batteries are capable of indefinite extension, and in the commercial plant, which will soon be erected, capacity will be provided to treat all the sawdust which comes from the digester, the capacity of the batteries to be proportioned to the contents of the disgester. The vats are connected by pipes, which are controlled by valves, and the contents are pumped from one vat to another as the process proceeds, care being taken to bring the sawdust richest in sugar in contact with the strongest solution, whereas the sawdust which is nearly exhausted of its sugar is treated with pure water. When the vats have been treated with ten washings they are emptied, refilled and the process repeated. From 450 to 500 pounds of sugar are thus obtained from a ton of sawdust, and from 70 to 80 percent of this sugar is capable of alcoholic fermentation, the remainder being pentose, which is nonfermentable.

The sugar solution is pumped from the exhaustion battery into a receiving tank, Fig. 3, where the acid that remains is neutralized with carbonate of lime, this neutralization being necessary to facilitate the action of the yeast in promoting fermentation. From the neutralizing tank the solution is pumped into fermenting Vats, Fig. 4, the liquid at this stage being similar to the “mash” obtained in the process of making alcohol from grain. When the solution or “mash” has reached a temperature of about 130 degrees C. yeast is added, and in an incredibly short time—about half an hour—a brisk evolution of carbonic acid gas takes place. Fermentation proceeds with much rapidity, and after eight to ten hours the process is complete. It is interesting to note here that fermentation of grain “mash” requires 72 hours. Upon the completion of the fermentation process the liquid is passed into the distillery, which is equipped with an ordinary still and condenser.

Careful tests have been made with white pine of the North, white and red cedar from the Pacific Coast, and yellow pine from the South. The first experiments were made with white pine, but all of these woods it has been found, can be treated advantageously for the production of ethyl alcohol. It was with some misgiving that yellow pine was used, as this wood is rich in turpentine, and fears were entertained even by Professor Classen himself that this fact would result injuriously. Much to the surprise of the chemists, however, it was not only found possible to produce alcohol in an equal amount as from other woods, but turpentine was recovered to a large extent, without in any away interfering with the production of alcohol, the turpentine being recovered at the same time as was the sulphurous acid.

As has been previously stated, the Highland Park plant was for three months under the supervision of Professor John H. Long. Upon his retirement the management passed into the hands of Otto Sjostrom, a German chemist and assistant to Professor Classen, under whose direction much of the work at the original plant erected at Aix-la-Chapelle was carried on.

Charcoal and Other By-Products. The report of Oscar Daube, general manager of the American Chemical & Carbon Company of New York City, upon the utilization of the sawdust residue is of special interest to owners and operators of charcoal blast furnaces, especially those who have already installed wood alcohol plants. The report is as follows:

Some time ago I visited your works at Highland Park and examined with great care and interest the Classen process for producing ethyl alcohol from sawdust, and consider the same practical and of great importance. Following your suggestions that I examine the tailings left after the fermentable sugar is extracted from the sawdust and report on the practical use to which these can be put. I had some of the tailings sent to my laboratory in New York, where I have made exhaustive tests during the last two months.

I have not the slightest doubt in advising you that the tailings may be briqueted, and from these briquettes charcoal of the highest grade suitable for all blast furnaces or other purposes requiring a first-class charcoal free from impurities may be obtained. The briquettes are made by pressure only, without the use of any binder. The charcoal is made from the briquettes in exactly the same way that charcoal is produced from wood and the usual by-products, such as wood alcohol, acetate of lime, wood tar, &e, are obtained.

I have made a very careful analysis of the charcoal to determine the percentage of carbon in it, and this analysis has been verified by the Metallurgical and Analytical Laboratory at 52 Beaver street. New York. I obtained with 850 degrees F. 87 1/2 percent of carbon, which carbon is equal to that obtained by any other process. Ordinary charcoal is made from wood of different shapes and sizes, but as your briquettes are of uniform size the charcoal obtained therefrom would be more uniform in quality and more easily charred.

I also make the statement that so far as ash, sulphur and other impurities are concerned, there will be no more of these than in the present method of making carbon from wood. If it is found advisable after your large plant is established, it is equally possible to make charcoal from the tailings without briqueting the tailings. The granular charcoal thus made may be formed into bricks afterward. The amount of charcoal obtained from the briquettes is from 40 to 42 per cent.

I consider one of the great advantages of your process is that you make charcoal from green waste sawdust after you have extracted your ethyl alcohol, while an ordinary charcoal plant requires that the wood be seasoned for at least 18 months. You thereby save capital required to purchase and carry the wood and eliminate risk from danger of fire.

The figures I give you are from soft wood sawdust (long ton). The figures on wood alcohol and acetate of lime would be largely increased if hard 'wood sawdust were used. Hardwood sawdust is obtained in large quantities in Northern Michigan and elsewhere. A complete 25-ton daily plant to make briquettes, charcoal and by-products would not cost to exceed $25,000. The gross returns per day from such a plant would be: 1,000 bushels charcoal, at 10 cents per bushel. . . . . . . . . . $100.00 8 1/2 gallons wood alcohol, at 65 cents per gallon. . . . . . . . 53.62 750 pounds acetate of lime, at 1 1/2 cents per pound. . . . . . 11.25 125 gallons wood tar, at 5 cents per gallon. . . . . . . . . . . . 6.25

Classen Lignum Company. The Lignum Inversion Company of Chicago, with a capital stock of $110,000, is the organization which has secured the Classen patents in the United States, and under whose direction all work in this country thus far has been accomplished. J. M. Ewen of Chicago is president, and J. K. George of London managing director. A number of wealthy and influential business men of Chicago, Pittsburgh and New York have become interested in the company, as well as large saw mill interests in Mississippi. It is understood that the Lignum Inversion Company is soon to be converted into the Classen Lignum Company, with a capital stock of $2,500,000, and arrangements will be shortly completed for the erection of a plant for the manufacture of alcohol by the Classen process, with a capacity of 100 tons per day, at a point in the South, and a contract has been signed for the erection of another plant of equal capacity in Northern Michigan.

1908
From Zeitschrift für angewandte Chemie (Journal of Applied Chemistry) in 13. November 1908. This is a German chemistry journal. This starts on page 2353 of the journal (PDF page 923). The book is from the Indiana University Library and scanned by Google.

This is taken directly from the PDF. There are many OCR errors with this section. Help is needed in cleaning up both the German version and the English translation.

This article was condensed and printed in English as "PRODUCTION OF ALCOHOL FROM CELLULOSE." in the April 10, 1909 edition of SCIENTIFIC AMERICAN SUPPLEMENT No. 1736.

On the question of the formation of alcohol from cellulosic materials. By Dr.-Ing. Theo Koerner.

Zeitschrift für angewandte Chemie (German) November 13, 1908
Zur Frage der Bildung von Alkohol aus cellulosehaltigen Stoffen.

Von Dr.-Ing. Theo Koerner.

( Aus dem organisch-chemischen Laboratorium der technischen Hochschule zu Dresden. Mitgeteilt von E. v. Meyer.)

(Eingeg. d. 12./10. 1908.)

Der Gedanke und das Bestreben, aus Holz Alkohol zu gewinnen durch Hydrolyse, das heißt Umwandlung in Traubenzucker und nachherige Vergärung, ist älter, als man annehmen sollte. Bereits im Jahre 1819 findet sich in Gilberts Annalen der Physik (63, 348) und Ann. Chim. (18, 172) eine Abhandlung : „Über die Verwandlung des Holzstoffes mittels Schwefelsäure in Gummi, Zucker, und eine eigentümliche Säure, und mittels Kali in Ulmine", entdeckt von H. Braconnot. Diese Arbeit wurde vom Verf., der Professor in Nancy war, am 4. November 1819 der französischen Akademie der Wissenschaften vorgelegt. Ein Jahr später wurde sie im Dingl. Journ. (I, 312) abgedruckt.

Braconnot führt aus, daß sich die alten Chemiker mit der Ansicht begnügt hätten, Schwefelsäure wirke verkohlend auf Pflanzensäuren ein. Unter den neueren Chemikern habe Berthollet, später Fourcroy und Vauquelin sich bemüht, diese Erscheinungen weiter aufzuklären. Er sei nun zu anderen Resultaten gelangt, und zwar habe er beim Behandeln mit kalter Schwefelsäure vom spez. Gew. 1,827 (91,5%) eine starke Erhitzung unter Entweichen von schwefliger Säure beobachtet. Beim Verdünnen, Abfiltrieren und Neutralisieren mit Kalkcarbonat habe sich eine gummiartige Masse ausgeschieden. Erhitze man nun diese gummiartige Substanz mit verdünnter Schwefelsäure, so entstehe Zucker. Dieser sei auskristallisierbar und vergärbar gewesen.

Die Entdeckung erregte Aufsehen, und es wurden große Hoffnungen an ihre technische Ausführung geknüpft. Schon 1820 findet sich eine weitere Abhandlung über diesen Gegenstand von Vogel, der ähnliches wie Braconnot fand und seine Versuche auf Papier, Baumwolle, Stroh, Kork und alte Manuskripte ausdehnte.

1854 lenkt Arnould wieder das allgemeine Interesse auf das Verfahren durch eine Abhandlung im Dingl. Journ. (134, 219). Er hofft durch die Einführung der Alkoholgewinnung aus Holz einen großen Teil des Getreides wieder seiner ursprünglichen Verwertung zuzuführen. Nach seinen Angaben hat er 80—90% von bestimmten Hölzern in lösliche Produkte verwandeln können durch Anwenden von 110 Teilen konzentrierter Schwefelsäure auf 100 Teile Holz. Melsens schreibt 1855 in „Genie industriel" über das Vermindern der Konzentration der angewendeten Schwefelsäure auf 3—5% und wendet das Verfahren hauptsächlich auf Fabrikationsrückstände an. Er ist der erste, der im Autoklaven arbeitete und Temperaturen bis zu 180° anwendete.

Auf eine Anregung des polytechnischen Vereins zu München beschäftigte sich 1855 Pettenkofer mit diesem Thema und veröffentlichte seine Resultate im Bayr. Kunst- und Gewerbeblatt 1855 (S. 136). Er führte dort vergleichende Rechnungen zwischen Brennereiverfahren und Holzhydrolyse aus, die zum Nachteile der letzteren ausfielen. Tribouillet versuchte schon 1854, die konzentrierte Schwefelsäure der verzuckerten Holzlösung anderweitig auszunutzen, indem er die Aufschlüsse zur Zersetzung der Kalkseifen der Stearinkerzen fabrikation verwendete. 1855 wurde unter der Leitung des Chemikers Pelouze in Paris eine Fabrik zur Bereitung von Weingeist aus Holzfaser gegründet. Sie scheint aber nicht lange existiert zu haben; denn nur noch einmal (1859) finden wir einen Hinweis durch eine von Pelouze veröffentlichte Abhandlung (Dingl. Journ. 150, 394), die nichts wesentlich Neues bringt. Außer dieser Fabrik sollte nach Varrentrapp (Dingl. Journ. 181, 233) noch eine fabrik mäßige Ausübung der Weingeistbereitung aus Holz in Genf versucht werden, die neben Papierstoff aus den inkrustierenden Substanzen „große Mengen" Alkohol zu gewinnen gedachte.

1867 erschienen Versuche von l'aycn über die Cellulosc. Sie gehen auch von der Papierstoffdarstellung aus, indem aus den ligninhaltigen Ablaugen als Nebenprodukt Alkohol erhalten werden soll. Dr. J. MattheuB will aus Torf vergärbare Dextrose gewinnen.

Am 2./ 12. 1894 patentierte man (D. R. P. 92079) in Deutschland dem Chemiker Simons en aus Christiania ein Verfahren zur schnellen Verzuckerung cellulosehaltiger Materialien mit Hilfe von 0,4—0,8%igen Säuren bei 7 Atm. Druck und darüber. Der Prozeß soll in 10—30 Minuten beendet sein. Simonsen gewann aus 1 kg Holz 60 g Alkohol, also eine gegenüber früheren Angaben rocht bescheidene Ausbeute.

Im Frühjahr 1898 wurde eine längere Arbeit des eben erwähnten Erfinders in Deutschland bekannt. Sie wurde von dem polytechnischen Vereine zu Christiania mit der goldenen Medaille belohnt und durch diese Zeitschrift (II, 195 [1898]) verbreitet, Si monsen stellte Versuche über den Einfluß des I >ruckcs, der Wassermengen, der Inversionszeit und der Säuremengen bei der Inversion cellulosehaltiger Materialien an. Er gelangte bei Anwendung von

Sulfitcellulose zu Zuckerausbeuten von 45%, er hält aber höhere Ausbeuten für ausgeschlossen, da die hohe Temperatur bei der Inversion der Cellulose eine teilweise Zersetzung des gebildeten Zuckers bewirke. Leider bestimmte er die Zuckermengen mit Fehling scher Lösung und versuchte nnr an einem Beispiel den Nachweis zu führen, daß aller durch Fehling sehe Lösung bestimmte Zucker vergärbar sei. Bei den Versuchen mit Sägespänen findet er die vorteilhafteste Ausbeute bei 1/4 ständigem Erhitzen von 100 g Sägespänen mit 500 cem 0,5%iger Schwefelsäure unter 9 Atm. Druck. Die Vergärungsversuche des erhaltenen Zuckers führten nur bei wenigen Versuchen zu positiven Resultaten. Hier wurde als Höchstausbeute aus 100 g Sägespänen 6,5 cem (d. s. 5,1 g) absoluter Alkohol erhalten.

Er kommt zu dem Schluß, daß Holz sich wider Erwarten leichter als Cellulose invertieren lasse; und die Versuche scheinen die Annahme zu bestätigen, daß der entstandene Zucker der Cellulose des Holzos entstamme, da bei Sägespänen die Zuckerausbeute der aus Cellulose des Holzes zu erhaltenden entspricht.

Am 15. Februar 1899 wurde dem Dr. Alexander Classen aus Aachen das erste Patent auf ein Holzverzuckerungsverfahren erteilt (D. R. P. 118 868). Es besteht in starkem Pressen eines Gemisches von Sägespänen und Schwefelsäure von 57° Be. Die Masse erhitzt sich von selbst, wird dann zerkleinert und mit Wasser gekocht. Ein Verfahren (D. R. P. 118 540), die Ausbeute bei der Holzinversion durch Kochen mit schwefliger Säure und Schwefelsäure oder nur schwefliger Säure, und durch nachherige Oxydation derselben zu Schwefelsäure, zu erhöhen, wurde ihm am 24./9. 1899 geschützt. Hieran schließen sich drei Patente vom 12./5. 1900 (D. R. P. 118 542, 118 543, 118 544). Das erste besagt, daß man die Holzsubstanzen mit Chlorwasser im Autoklaven erhitze und dann schweflige Säure zur Bildung von Schwefelsäure einführe. Das zweite Patent will die Ausbeute an Zucker dadurch erhöhen, daß man das Rohmaterial mit schwefliger Säure erhitzt und dann zur Bildung von Schwefelsäure Chlor einleitet. Das dritte Patent besteht darin, daß man erst die Sägespäne mit schwefliger Säure erhitzt und zu deren Umwandlung in Schwefelsäure Luft oder Sauerstoff einführt. Die Einführung der schwefligen Säure, der Chlors und der Luft oder des Sauerstoffs soll nach allen drei Patenten bei 120—125° erfolgen. — In einem Patent vom 17./10. 1900 (D. R. P. 121 869) wird C 1 a s s e n die Behand lung des Holzes mit Sehwefelsäureanhydriddämpfen patentiert. Zu diesem wird im Zusatzpatent 123 911 vom 17./10. 1900 auch auf das nachherige Erhitzen auf 125—135° Anspruch erhoben.

Während Classen durch Zusatz von schwefliger Säure eine Erhöhung der Ausbeute erzielen will, suchen G e n t z e n und Dr. Roth (D. R. P. 147 844a vom 26./S. 1901) im Ozon das die Ausbeute erhöhende Agens. Der Zusatz von Ozon soll einer seits die Ligninsubstanzen zu vergärbaren Pro dukten oxydieren, andererseits die die Gärung hin dernden Stoffe durch Oxydation ausscheiden. Nach den Angaben der Patentschrift erhält man bei Anwendung von Ozon aus 100 kg Kiefernholz 34 kg vergärbare Dextrose und aus 100 kg Fichtenholz sogar 40 kg. Man arbeitet mit 3—4%iger Schwefeloder Salzsäure und bei einem Drucke bis zu 20 Atm. Die Dauer des Prozesses liegt zwischen 10 bis 30 Minuten.

Am 4./9. 1904 sprach der Dipl.-Ing. Reiferscheidt in einer Versammlung des Bezirkvereins Saclisen- Anhalt über die Gewinnung von Alkohol aus Holzabfällen. Er hat durch Versuche die Simonsen sehen Zahlen und einzelne andere Arbeiten, z. B. das Patent von C 1 a s s e n nachgeprüft. Er kommt im Gegensatz zu P a y e n und übereinstimmend mit Siracnsen zu der Überzeugung, daß der Alkohol nur aus Cellulose stamme, und das Lignin bei der Holzverzuckerung eher störend als fördernd wirke. Er findet dann, daß bei den C 1 a s s e n sehen Patenten am besten 8,5—9,5%ige schweflige Säure angewendet wird und die günstigste Versuchsdauer 1 Stunde sei; die günstigste Temperatur liege zwischen 140—150° bei 4—5 Atm.

Im Jahre 1905 (8./G.) wurde dem Kaufmann Arno Bornen aus Wien in England ein Patent für die Darstellung von Zucker aus cellulosehaltigen Materialien erteilt. Es behandelte die Rohmaterialien mit 5%igen Lösungen von Ätzalkalien bei 30—40°, wobei ein Teil der Bestandteile, die er „amyloidartig" nennt, in T.iösung geht. Durch Kochen der abfiltrierten Laugen sollen die „amyloidartigen Bestandteile in Zucker übergehen.

Werfen wir noch einen Rückblick auf das Gesagte, so finden wir, daß die Angaben über die Ausbeute an Zucker und Alkohol sehr auseinandergehen. Die höchsten Angaben sind in der ältesten Literatur verzeichnet; so will Braconnot 1817 aus 20,4 g Leinwand 23,3 g Zucker gewonnen haben. Oft beschränkte man sich bei den Ausbeuteangaben auf den Ausdruck „große Mengen" Zucker. Arnould fand 1854 noch aus 100 g Holz 110 g Zucker. Später treten auch Angaben über die Alkoholausbeute auf, doch sind diese schon bedeutend kleiner; so fand B a s s e t aus 100 g Holz 32 cem Alkohol, Ludwig 36,6 g (ca. 41 cem) Alkohol. 1867 stellte Payon aus 100 g Holz 21,3 g Zucker dar und Ende 1898 Simonsen60g Alkohol aus 1 kg Holz.

Aus dem Vorstehenden ist ersichtlich, wie oft man sich schon mit der Verzuckerung der Cellulose beschäftigt hat, und die großen- Unterschiede, die in den Ausbeuten enthalten wurden, zeugen von der Unkenntnis der wichtigsten Einflüsse. Die einzige Übereinstimmung wurde wohl von Simonsen und von Reiferscheidt erzielt, die beide aus 100 g Holz ca. 6 g Alkohol erhielten, eine Ausbeute, die auch durch die vorliegende Arbeit bestätigt wird. Die Verschiedenheit und wohl besonders die UnVollständigkeit der Abhandlungen erschweren natürlich die Ausführung solcher Versuche und die Nachprüfung der Angaben bedeutend.

Die Anordnung meiner Versuche war im allgemeinen folgende. Das Rohmaterial (Holzsägespäne, Sulfitcellulose von H ö s c h in Heidenau und Stroh stoff von Dietrich in Weißenfels) wurde, je und je den Versuchen entsprechend, kürzere oder längere Zeit mit verdünnter oder konzentrierterer Schwefelsäure, teils mit, teils ohne Zusatz in einem ca. 2 1 fassenden Autoklaven erhitzt. Der Autoklav war aus Kupfer mit Blei ausgefüttert und von der ihn erhitzenden Glasflamme durch eine Luftschicht geschützt, so daß die Bunsenflamme keine direkte Zerstörung der eingeschlossenen Substanzen bewirken konnte. Oft wurde auch im Wasserbade gearbeitet. Nach Beendigung der Kochung wurde die saure Flüssigkeit vom festen Rückstand abfiltriert und die ersten 500 cem zur weiteren Verarbeitung verwendet. Das Filtrat war nach der Art der Ausgangsmaterialien verschieden gefärbt, vom dunklen Rotbraun bis zum hellen Orange. So sahen Filtrate von Holzeinschlüssen rotbraun aus, diejenigen von Sulfitcellulose rot und Ansätze mit Strohstoff sohön rotgelb. In saurer Lösung stehen gelassen, schieden sich nach einiger Zeit noch den Rückständen ähnliche Massen aus. Durch Alkalien wurden die Lösungen dunkel gefärbt, die von Sägespäne herrührenden dunkler als die aus Sulfitcellulose stammenden und diese wieder dunkler als diejenigen aus Strohstoff. Bei den ersten Versuchen wurde der Zuckergehalt mit Fehling scher Lösung durch Wägung des zu Kupferoxyd oxydierten Kupferoxyduls bestimmt. Es stellte sich aber bald heraus, daß der aus dieser Zuckermenge berechnete Alkohol nicht in allen Fällen dem durch Gärung gewonnen gleich kam, wie dies Simonsen (diese Z. 11, 225 [1898]) annimmt, da sich zwei hierüber angestellte Versuche wie 21,6 : 20,0 verhielten, also nur 8% Unterschied ergaben und man beim Brennereiverfahren mit 10—20% Verlust rechnen muß.

So fand ich z. B. ziemlich übereinstimmende Werte (jedenfalls innerhalb der Verlustgrenzen der Brennerei) bei folgenden Vorsuchen : Sägespäne mit 0,5%iger Schwefelsäure invertiert (Nr. 1) :

Alkohol aus Zuckerreduktion berechnet. 5,21 g

durch direkte Gärung erhalten 5,21 g

Sägespäne mit 0,5%iger Schwefelsäure invertiert nach vorherigem Behandeln mit Wasserdämpfen (Nr. 3) :

aus der Zuckerreduktion berechnet. . . 7,39 g

direkt durch Gärung erhalten 6,83 g

Sulfitcellulose mit 0,5%iger Schwefelsäure unter Zusatz von 2% Wasserstoffsuperoxyd (Nr. 14) invertiert :

aus der Reduktionszahl berechnet .... 16,08 g

direkt durch Gärung 14,64 g

Strohstoff mit 0,5%iger/ Schwefelsäure unter Zusatz von 2% ^Wasserstoffsuperoxyd invertiert (Nr. 15) :

aus der durch Reduktion bestimmten

Zuckermenge berechnet 8,51 g

direkt durch Vergärung 8,36 g

Im Gegensatz zu diesen stehen Bestimmungen, wo die Differenzen zum Teil sehr bedeutende sind :

(Nr. 2.) Beim Zusatz von S02 zum Einschluß des Versuches Nr. 1 ergab die aus dem Zuckerwert berechnete

Alkoholmenge 2,43 g statt 1,74 g (Nr. 2), durch Vergärung erhalten, und

Alkoholmenge 9,56 g statt 5,52 g (Nr. 6), durch Vergärung erhalten.

Der Versuch' 8, in dem Sulfitcellulose einfach mit 0,5%iger Schwefelsäure bei 8 Atm. gekocht wurde, lieferte eine Flüssigkeit, deren Alkoholausbeute nach der Methode mit Fehlingscher Lösung 10,94 sein sollte, und die bei der Vergärung nur 8,43 ergab. Ebenso erhielt ich beim Invertieren von Strohstoff mit 0,5%iger Schwefelsäure

8,52 g aus dem Zuckergehalt statt

5,4 g bei direkter Vergärung.

Diese Fehler rühren von anderen reduzierenden Substanzen her, die nicht vergärbarer Zucker sind; so konnten im Versuche Nr. 11 einmal größere Mengen eines Aldehyds mit schwefligsaurer Fuchsin lösung nachgewiesen werden, die sieh durch Rotfärbung von Scsamöl als Furfurol erwiesen. In diesem Versuche betrug die Alkoholmenge, aus dem durch Fehling sehe Lösung bestimmten Zuckergehalte berechnet, 7,66 g. während durch Gärung nur 2,12 g Alkohol erhalten wurden. Auch Simonsen will (diese Z. 8. 196 [1895]) Geruch von Furfurol beobachtet haben.

Aus diesen Gründen wurde in allen Versuchen der Alkohol durch Vergärung direkt bestimmt, und zwar auf folgende Weise : Ein Teil des auf ein bestimmtes Volumen aufgefüllten Filtrats wurde mit kohlensaurem Kalke neutralisiert, vom Rückständeabfiltriert, mit wenigen Tropfen Phosphorsäure versetzt und mit Hefe bei 25—30" während zwei bis drei Tagen vergoren. Die vergorene Flüssigkeit wTirde von der Hefe getrennt und nach Zusatz von wenig Tannin abdestilliert. Nachdem ungefähr ein Drittel übergegangen war, wurde die Destillation eingestellt, das Destillat zur Abstumpfung etwa gebildeter Essigsäure mit wenig kohlensaurem Kalke versetzt und noch ein bis mehrere Male (nach Bedarf) destilliert. Das spezif. Gewicht der erhaltenen, Alkohol enthaltenden Flüssigkeit wurde stets bei gleicher Temperatur mit dem Pyknometer bestimmt.

1. Vergleichende Versuche über die Verzuckerung von Sägespänen, Strohstoff und Sulfitcellulose mit verdünnter Schwefelsäure.

Die Frage, ob der durch Hydrolyse aus Holz entstandene Zucker der Cellulose allein entstamme, oder ob auch die Ligninsirbstanzen daran Anteil haben, ist vielfach erörtert worden. So nahm z. B. 1867 P a y c n an. daß der Zucker aus dem Lignin entstehe, und die Cellulose nicht angegriffen werde, da er im Großen aus Holz mit Salzsäure reine Cellulose für die Papierfabrikation erhalten wollte, und die inkrustierenden Substanzen dabei in Zucker überzuführen gedachte. Daß reine Cellulose mit Schwefelsäure hydrolysierbar ist, stehtheute fest, und nur die Frage, ob auch Lignin in Zucker überführbar sei, ist nocli zu beantworten. So scheint das Lignin nach den Versuchen von Lindsey keine Beziehungen zu Hexose zu haben, da es nicht gelang, aus der Holzflüssigkeit (Sulfitlauge) Lävulinsäure zu erhalten, die sehr leicht aus den Kohlehydraten entsteht. Würde man Lignin bestimmt als kein Kohlehydrat erkennen, so würde auch seine Inversion so gut wie ausgeschlossen sein. — Aus Simonsens Versuchen kommt man zu der Uberzeugung, daß der bei der Inversion entstandene Zucker allein der Cellulose entstammt, da aus Holz 20% Zucker, aus Cellulose 45% Zucker erhalten wurden, und bei Annahme, daß Holz 50% Cellulose enthält, der aus dem Holze gewonnene Zucker ungefähr dem aus der Cellulose des Holzes allein zu erhaltenden entspräche. Da die Simonsen sehen Bestimmungen mit Fehling scher Lösung, ausgeführt wurden, und diese Methode, wie bereits gezeigt, nicht einwandfrei ist, so wurden mehrere Versuche mit Holzsägespänen, Sulfitcellulose und Strohstoff unter den gleichen Bedingungen ausgeführt, indem je 40 g in 500 cem 1/2%iger Schwefelsäure ' während zwei Stunden 6—8 Atm. erhitzt und dann, wie bereits oben erwähnt, weiter verarbeitet wurden. Die Ausbeuten an Alkohol waren folgende :

Holzsage- Sulfit- Strohspäne cellulose stoff 5.21% 13,69% 9.56% 6,83% 11,97% Mittel 6,02% 12,83% 9,56%

Die höchste Ausbeute lieferte die Sulfitcellulose mit 12,83 g Alkohol im Durchschnitt auf 100 g trockenes Ausgangsmaterial. Es ist das ungefähr das Doppelte des Ausbeutewertes für Sägespäne. Nimmt man die Sägespäne mit 50% Cellulose an. so würde der aus den Sägespänen erhaltene Alkohol dem aus der Cellulose des Holzes allein zu erhaltenden entsprechen. Die Versuche bestätigten die Simonsen sehen Angaben und befestigten die Ansicht, daß der Zucker allein der Cellulose entstamme und das Lignin nicht in Zucker überführbar ist.

Um auf diesen Punkt genauer eingehen zu können, wurden Bestimmungen des Cellulosegehaltesausgeführt, und zwar für Holz und Sulfitcellulose nach der Methode von Fremyund Terreil (Z. anal. Chem. 1, 282). Das' Aufschließen geschieht hier durch 36stündiges Stehenlassen in Chlorwasser. Darauf wird der Küekstand mit Pottasche ausgekocht, die nun die Nichtcellulosesubstanzen leicht lösen soll. Zum Schluß wäscht man noch mit verdünnter Säure aus und trocknet bei 136°; durch Wägen in einer Platinschale, Glühen und Zurückwägen wird die Cellulose bestimmt.

Es wurden nach dieser Methode aus 0,8804 g trockenem Holze 0,4387 g Cellulose erhalten, und aus 0,8749 g 0,4224 g, was 49,83 und 48,28% entsprechen würde. Noch weniger gut stimmen die Werte für Sulfitcellulose unter sich überein. Aus 0,9386 g und 0,9617 g Sulfitcellulose wurden 0,7845 g Cellulose erhalten, d. s. 83,598 und 79,693%.

Der Gehalt des Strohstoffs an Cellulose wurde nach dem Verfahren von Henneberg und Wender (Eisner, Praxis des Chemikers bei der Untersuchung von Nahrungsmitteln, S. 44) bestimmt. Die Methode wird vielfach in der Nahrungsmittelchemie zur Bestimmung der „Rohfaser" angewendet, eignet sich aber nicht für Holz, da das Holz scheinbar nicht fein genug verteilt war. Der Strohstoff wurde, beim Kochen zu einer feinen schleimigen Masse, und die Resultate waren folgende :

Angewandte Substanz .... 2,6396 g 3,3728 g

Differenz der bei 105° gewogenen Cellulose und ihrem Glührückstand 1,8241 g 2,3167 g

in % also 69,18 und 68,69

Stellt man die Cellulosezahlen den Ausbeuten gegenüber, so findet man folgendes :

% Alkoholan

Cellulose ausbeute

Holz 49,05 6,02 ( 6,02)

Sulfitcellulose 81,64 12,83 (10,02)

Strohstoff 68,90 9,56 ( 8,46)

Die Zahlen verhalten sich oberflächlich proportional. Für Sulfitcellulose und Strohstoff kann man die zu erwartenden Zahlen der Ausbeuten aus den Cellulosegehalten und den Alkoholausbeuten des Holzes berechnen. Die Zahlen sind in Klammern beigefügt. Die Übereinstimmung ist eine sehr schlechte. Der Grund, daß die Ausbeuten in Wirklichkeit größer sind, dürfte auf die schlechte Methode der Cellulosebestimmung zurückzuführen sein, die zu niedrige Werte liefert.

II. Versuche über die Wirkung der schwefligen Säure bei der Verzuckerung des Holzes.

Es wird vielfach angenommen, daß die schweflige Säure einen günstigen Einfluß auf die Ausbeute an Zucker bei der Holzverzuckerung ausübt. Die älteste Notiz in dieser Hinsicht ist wohl das amerikanische Patent 654 518 (Chem.-Ztg. 24, 693 [1900]). Über die Wirksamkeit der schwefligen Säure findet man in der Literatur zweierlei Auffassungen :

1. Man will die schweflige Säure als die bei der Inversion nötige Säure verwenden (Allgem. Chemikerzeitung 5, 646 nnd C 1 a s s e n, D. R. P. 130 980).

2. Man will durch eine Vorbehandlung mit schwefliger Säure eine leichtere Angreifbarkeit des Materials erzielen und durch Oxydation zu Schwefesäure mittels Luft, Sauerstoff oder Chlor die für die Inversion nötige Säure schaffen. In dieser Richtung bewegen sich die Patente von C 1 a s s e n : D. R. P. 118 540, 118 543, 118 544.

Zuerst wurden darum zweimal je 40 g Sägespäne einer Vorbehandlung mit 2%igem Süß wasser während zwei Stunden bei 6—7 Atm. unterworfen und darauf mit 0,5% Schwefelsäure bei demselben Drucke gekocht. Die weitere Verarbeitung geschah, wie oben erwähnt, und ergab auf 100 g trockne Sägespäne 4,16 g und 5.52 g Alkohol. Hieraus geht hervor, daß eine Vorbehandlung mit S02 die Ausbeute an Alkohol nicht vermehrt, eher vermindert, da ohne S02 -Zusatz 6,02 g erhalten wurden.

III. Versuche über die Wirkung von Oxydationsmitteln bei der Holzverzuckerung.

Die Hydrocellulose, deren Formel wir als Ci2H22On (C. 15, I, 933) annehmen wollen, können wir unter Zugrundelegen der einfachsten Celluloseformel uns aus zwei Molekülen Cellulose durch Aufnahme von einem Molekül Wasser entstanden denken :

2CeH10O5 + H20 C12H22Ou Cellulose Hydrocellulose.

Der Kohlenstoffgchalt sinkt dabei von 44,44 auf 42,11%, während der Sauerstoffgehalt von 49,39 auf 51,46 und der Wasserstoff von 6,17 auf 6,34% steigt. Es lag nun der Gedanke nahe, daß die Hydrocellulose viel leichter in Zucker überführbar sei, als die Cellulose, da sie nach ihrer Zusammensetzung dem Zucker schon um ein Molekül Wasser näher steht, als die Cellulose. — Die Hydrocellulose wurde nach der Vorschrift von U 1 z e r (Fischer- Wagner, Jahresber. der Chemischen Technologie 1905, II, 192) dargestellt,

Mit 40 g dieser Hydrocellulose wurde eine Kochung mit 500 cera 0,5%iger Schwefelsäure während ca. 3 Stunden auf 153—160,5° ausgeführt. Die weitere Aufarbeitung geschah, wie eben angeführt, und es wurden aus 100 g trockener Hydrocellulose IT, 95 g Alkohol erhalten.

Die Zahl ist die höchste von mir erhaltene Ausbeute.

Es wurden erhalten als Mittelwerte aus :

Holz 6,02% Alkohol

Strohstoff 9,56%

Sulfitcellulose 12,83%

Hydrocellulose .... 17,95%

Nun wurde versucht, durch Zusatz von Oxydationsmitteln aus den Ausgangsmaterialien vorübergehend der Hydrocellulose ähnliche Substanzen zu erzielen, die analog der guten Ausbeute der reinen Hydrocellulose die Ausbeute erhöhen müßten. Der Zusatz von Oxydationsmitteln zur Hydrocellulose verminderte die Ausbeute, so z. B. bei Zusatz von 2%igem Wasserstoffsuperoxyd auf 11,12%, bei Chromsäure sogar auf 3,95%.

A. Zusätze von Wasserstoffsuperoxyd zu Einschlüssen von celluloseh altigen Substanzen und 0,5% iger Schwefelsäure.

Es wurden in drei Ansätzen je 40 g Sägespäne, Sulfitcellulose, Strohstoff mit 500 cem 2%igem Wasserstoffsuperoxyd und 2,5 g konzentrierter Schwefelsäure (so daß also eine 0,5%ige Säure vorhanden war), während drei Stunden bei 7,4—9 Atm. auf 163—166° erhitzt,

Nach dem öffnen wurde noch einige Minuten gekocht und dann, wie oben angegeben, weiter ge arbeitet: es ergaben sich folgende erhöhte Ausbeuten :

bei Invertierung Zusatz von

ohne Zusatz 2 % igem H202

Holz 6,02 9,05 u. 10,76

Sulfitcellulose 12,38 14,64

Strohstoff 9,56 10.26

Bei Holz ist die Erhöhung, die durch Wasserstoffsuperoxydzusatz bewirkt wird, am größten, bei Strohstoff am geringsten.

B. Versuche mit chromsaurem Kalium als Oxydationsmittel.

Da dieselbe Sauerstoffmenge, wie bei den Versuchen mit Wasserstoffsuperoxyd angewendet werden sollte, so setzte ich jedem Ansatz 28.8 g bichromsaures Kalium und 38,4 g Schwefelsäure zu (500 com 2% H202 enthält 10 g H202 oder 4,7 g aktiven Sauerstoff; dieselbe Menge liefert genannte Menge biehromsaures Kalium).

Die schädliche Wirkung der Chromverbindungen auf die Hefe wurde durch Fällen mit Kalk vor der Vergärung aufgehoben.

Je 40 g Sägespäne, Sulfitcellulose oder Strohstoff wurden unter gleichen Verhältnissen während 3 Stunden auf 7,4—8,7 Atm. erhitzt. Nach dem öffnen wurde die hellgrüne Lösung, wie oben erwähnt, weiter verarbeitet.

Die Ausbeuten stellten sich bei Invertierung

mit Zusatz von

ohne blohrom saurein

Zusatz Kalium und

Schwefelsäure

Holz 6,02 3,23

Sulfitcellulose 12,38 2,34

Strohstoff 9,56 3,23.

Die Einwirkung von Kaliumbichromat verminderte nach vorstehenden Versuchen die Alkohol ausbeute erheblich.

C. Versuche mit Kaliumpersulfat als Oxydationsmittel.

Das Kaliumpersulfat liefert beim Zerfall nach der Formel :

K2S208 = K2S04 + S02 + 02

also 270 g Kaliumpersulfat 32 g aktiven Sauerstoff. Um nun die gleiche Menge aktiven Sauerstoffs wie bei den Versuchen mit Wasserstoffsuperoxyd und chromsaurem Kalium zu erhalten, waren 40,7 g Kaliumpersulfat notwendig.

Es wurden parallele Versuche mit je 40 g Holzsägespänen, Sulfitcellulose und Strohstoff ausgeführt, die als Ausbeuten untenstehende Zahlen berechnen ließen.

bei Einschluß *eÄa'z

ohne Zusatz "^HS*

Holz 6,02 4,22

Sulfitcellulose 12,38 7,32

Strohstoff 9,56 2,57

Nach Zusatz von Kaliumpersulfat sank also die Ausbeute bei der Verzuckerung der angewendeten oellulosehaltigen Rohmaterialien erheblich.

D. Zusatz von Ozon zu den Einschlüssen bei der Holzverzuckerung.

Von Dr. Roth und R. Gentzen wurde zur Erhöhung der Zuckerausbeute bei der Verzuckerung der Sägespäne Ozon als Oxydationsmittel vorge schlagen und das Verfahren durch D. R. P. 147 844a geschützt. In der Patentschrift wird ausdrücklich erwähnt, daß das Ozon die Oxydation des Lignins in Zucker bewirke und gleichzeitig die gärungshindernden Stoffe durch Oxydation ausscheide. Auffallend ist die Behauptung, daß die inkrust ierenden Körper den Kohlehydraten sehr nahe stehen, während J. B. Lindscy (Inaugural-Dissertation, Göttingen 1891) ausdrücklich erwähnt, daß er aus den ligninreichen Sulfitlaugen der Sulfitcellulosefabriken nur geringe Mengen von Lävulinsäure erhalten habe und nach den Untersuchungen von Wehnet (Lieb. Ann. 343, 333) die Entstehung der Lävulinsäure ein unzweifelhaftes Zeichen für die Gegen wart von Kohlehydraten ist. Dem Patente nach wird das Ozon unter 3—4 Atm. Druck während 10—30 Minuten dem Rohmaterial zugeführt und dann mit 3%iger Schwefelsäure gekocht. Angaben über Konzentration des Ozons fehlen vollständig; ebenfalls sind die Angaben über die Ausführung des Prozesses sehr mangelhaft. Es finden sich nur einige Notizen über Ausbeute, z. B. sollen aus 100 kg Kiefernholz 34 kg vergärbare Dextrose zu erhalten sein; das sind bei einem Gehalt von 50% Cellulose 61,2% Ausbeute, bei Fichtenholz und Stroh sind sie noch höher angegeben.

Es wurden von mir zuerst zwei Versuche mit beliebigem Ozongehalt ausgeführt bei einer Einwirkungsdauer von 25—30 Minuten. Der erste Prozeß wurde in der Wärme, der letztere in der Kälte ausgeführt. Die Einleitung des Ozons geschah bei gewöhnlichem Drucke, da mir Apparate zur Überwindung von 2—4 Atm. nicht zur Verfügung standen. Die Alkoholausbeute war im ersteren Falle 1,5 g aus 100 g trocknen Sägespänen und im zweiten Versuche 4,1 g; also stets geringer als bei einfachem Kochen mit Schwefelsäure.

Der folgende Versuch schließt sich an das Patent näher an, 40 g Sägespäne mit 15% Wassergehalt wurden 20 Minuten einem 2%igem Ozonstrom ausgesetzt, darauf in 3%iger Schwefelsäure während 1 Stunde auf 4—5 Atm. erhitzt. 200 cem des auf 600 cem aufgefüllten Filtrats ergaben bei der Vergärung 105 cem alkoholisches Destillat vom spez. Gew. 0,99903, woraus sich auf 100 g trocknes Holz 4,72 Alkohol berechnen.

Zwei Versuche wurden mit 6%igem Ozon während 21/i Stunde ausgeführt. Die Sägespäne waren mit der dreifachen Menge Wasser befeuchtet und in ein U-Rohr gefüllt, so daß der Ozonstrom darüber hinweggeleitet wurde.

Zwei weitere Versuche mit 0,7% Ozon wurden bei der Einwirkungsdauer von 10' und 30' ausgeführt. Ein anderer mit 1,8% Ozon bei einstündiger Einwirkung. Die Resultate sind in untenstehender Tabelle veranschaulicht.

Leider wurde für die Darstellung des Ozons erst nach mehrfachem Wechseln ein iialbwegs brauchbarer Apparat in der Berthelot sehen Röhre gefunden, aber auch hier war eine vollständige Gleichmäßigkeit des Ozonstromes nicht zu erzielen, so daß die Bestimmungen der 03 -Mengen sehr ungenau ausfielen ; aber schon im Vergleich mit diesen Werten ist deutlich zu ersehen, daß die Zuckermenge bei steigender Ozonmenge abnimmt.

Betrachten wir folgende Versuche : !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! Nr. DdOaeuserr- Einwirkung Verbrauchter LiOitenrjn % o„ also Oa "o c_* N 51 10' o 0,7 14 cem 6,61 = 45 20' 4 2,0 80 cem 4.7 53 30' 7 0,7 49 cem 5,78 55 60' 13 1,8 234 cem 0,6 47 135' 35 5,5 1925 cem 0,35 !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Aus diesen Zahlen ist zu erkennen, wie die Alkoholausbeute sich proportional der Ozonmenge verringert. Ein Teil des Ozons wird durch die Wärme, bei der die Einleitung erfolgt, ist, zerstört worden sein, aber trotzdem ist noch sehr deutlich die ungünstige Einwirkung des Ozons zu erkennen. Nach 10 Minuten (51) war bei einem 0,7%igen Ozonstrom und 50° noch keine schädliche Einwirkung zu verzeichnen. Die Ausbeute fiel aber schon bei 30 Minuten Dauer des 0,7%igen Ozonstroms. Bei Anwendung des stärkeren 2%igon Ozonstromes ist schon nach 20 Minuten eine bedeutend größere Differenz zu ersehen, da die Menge Ozon auf 80 cem angestiegen ist. Analog dem Steigen der Ozonmenge fällt die Alkoholausbeute bis auf 0,35 g für 100 g Holz. — Um festzustellen, wie die 03- Einwirkung auf Sulfitcellulose wirke, wurde folgender Versuch angesetzt.

40 g Sulfitcellulose von 9,5% Wassergehalt wurden mit 150 cem Wasser benetzt und während einer Stunde einem Ozonstrom von 1,81% Os ausgesetzt, bei einer Wasserbadtemperatur von 39°. Darauf wurde die Sulfitcellulose während einer Stunde bei 155—160° mit 300 cem 3%iger Schwefelsäure gekocht. Die Vergärung lieferte so wenig Alkohol, daß sich auf 100 g trockne Sulfitcellulose 1.42 g Alkohol berechnet.

Das Ozon wirkt also auch bei Sulfitcellulosekochung schädlich.

Zusammenfassung der gewonnenen Ergebnisse.

Bei den vergleichenden Versuchen über die Verzuckerung cellulosehaltiger Rohmaterialien, des Holzes, des Sauerstoffs und der Sulfitcellulose wurde die von Simonsen angegebene Ausbeute von 6 g Alkohol aus 100 g trocknem Holze durch zwei Versuche bestätigt. Die größte Ausbeute an Alkohol ergab die prozentual den höchsten Cellulosegehalt besitzende Sulfitcellulose mit durchschnittlich 12,83 g Alkohol aus 100 g Ausgangsmaterial. Es ist dies die doppelte Menge des aus Holz zu erhaltenden Alkohols. Da das Holz ungefähr 50% Cellulose enthält, scheint das ein untrüglicher Beweis dafür, daß der entstandene Zucker der Cellulose entstammt und nicht dem Lignin, wie es P a y e n annahm, und es auch heute noch oft angenommen wird.

Die Zusätze von schwefliger Säure erwiesen sich, entgegen den Angaben der Patente von C 1 a s s e n - Aachen, als die Zuckerbildung hindernd ; auch nicht in einem einzigen Versuche wurden befriedigende Resultate erzielt.

Der Zusatz von Oxydationsmitteln zu den Einschlüssen verminderte in den meisten Fällen die Bildung von Zucker ; nur beim Zusätze von Wasser stoffsuperoxyd konnte eine höhere Ausbeute erzielt werden; beim Holze eine bis 50% der sonst zu erhaltenden Alkoholmenge betragende Zunahme. Aus diesem Resultat kann man schließen, daß schwache Oxydationsmittel die Cellulose in eine der Zuckerbildung geneigtere Verbindung überführen. Da die Ausbeute an Alkohol aus Hydrocellulose den Höchstwert von 17,95% erreichte, so liegt der Schluß nahe, daß daa Wasserstoffsuperoxyd die Cellulose in Hydrocellulose umwandelt, und dieser die größere Zuekerbildung zu verdanken ist. Die anderen angewandten Oxydationszusätze, wie das Kaliumbichromat, das Kaliumpersulfat und das Ozon, sind zu starke Agenzien ; sie oxydieren die Cellulose über die Hydrocellulose hinweg zu anderen Substanzen.

Der durch das Patent von Dr. Roth und Gentzen geschützte Zusatz von Ozon ergab das vollständige Gegenteil der dort aufgestellten Behauptung, indem der Ozonzusatz eine Verminderung an gärfähigem Zucker bewirkte. Die Abnahme der Ausbeute erfolgte ziemlich proportional den zugeführten Ozonmengen.

Im allgemeinen ist also die Ausbeute an Alkohol durch Hydrolyse des Holzes eine recht geringe, wenn man bedenkt, daß theoretisch aus 100 g Cellulose 56,91 g Alkohol entstehen können; denn selbst im günstigsten Falle wurden bei einfacher Hydrolyse nicht viel mehr als 25% der berechneten Menge Alkohol erzielt. Es liegt darum die Annahme nahe, daß aus dem Cellulosekomplex (CgHi0Os)x nur ein Teil abgespalten und in vergärbaren Zucker überführbar ist.

Zeitschrift für angewandte Chemie - Journal of Applied Chemistry (English) November 13, 1908
On the question of the formation of alcohol from cellulosic materials.

By Dr.-Ing. Theo Koerner.

(From the organic chemistry laboratory of the Technical University of Dresden. Communicated by E. v. Meyer.)

(Entered. D. 12/10. 1908.)

The thought and the quest to obtain wood alcohol by hydrolysis, that is conversion to glucose and subsequent fermentation is older than one would think. Already in 1819 found in Gilbert's Annals of Physics (63, 348) and Ann. Chim. (18, 172), a treatise. "About the transformation of the pulp by means of sulfuric acid in rubber, sugar, and a peculiar acid, and by potash in Ulmine", discovered by H. Braconnot This work was supported by the author, the professor in Nancy. was submitted on 4 November 1819, the French Academy of Sciences. One year later it was reprinted in Dingl. Journ. (I, 312).

Braconnot points out that the old chemists had contented themselves with the view, that application of sulfuric acid produced charring on a plant. Among modern chemists Berthollet, Fourcroy and Vauquelin later endeavored to further clarify this phenomena. He had now come to different conclusions, and that when treated with cold sulfuric acid of sp. Wt. 1,827 (91.5%) he had observed a strong heating from escaping sulphurous acid. When diluted, filtered and neutralizing with carbonate of lime, a gummy mass was excreted. Heat up this gum with dilute sulfuric acid, and sugar arises from it. This sugar was crystallizable and fermentable.

The discovery caused a sensation, and high hopes on their technical execution were made. Already in 1820 there is another treatise on the subject by Vogel which was similar as Braconnot and his attempts expanded on paper, cotton, straw, cork and old manuscripts.

1854 directs Arnould again the general interest to the method by a treatise in Dingl. Journ. (134, 219). He hopes through the introduction of alcohol from wood again supplied a large part of the crop of its initial utilization. According to him, he can transform 80-90% of certain woods in soluble products by applying 110 parts of concentrated sulfuric acid to 100 parts wood. Melsens writes 1855 in "Genie Industriel" about reducing the concentration of the applied sulfuric acid to 3-5% and shall follow the procedures mainly on manufacturing residues. He is the first who worked in an autoclave and temperatures up to 180 ° applying an end.

On a suggestion of the Polytechnic Association in Munich, 1855 Pettenkofer dealt with this topic and published his results in Bayr. Arts and Crafts Journal in 1855 (S. 136). He led there from comparative calculations between distillery process and Holzhydrolyse, which were to the detriment of the latter. Tribouillet tried already in 1854, otherwise exploit the concentrated sulfuric acid of wood saccharified solution by manufacturing used the insights to decompose the calcium soaps of tallow candles. 1855 was founded in wood fiber under the direction of chemist Pelouze in Paris a factory for the manufacture of alcohol. But she did not seem to have long existed; because only once (1859), we find a reference by a publish Pelouze treatise (Dingl. Journ. 150, 394), which brings nothing really new. Apart from this factory should after Varrentrapp (Dingl. Journ. 181, 233) have a factory-like pursuit of the spirit of wine preparation from wood in Geneva are trying the "large quantities" intended to win next Alcohol pulp from encrusting substances.

1867 published experiments of l'aycn on Cellulosc. You also assume the pulp representation by should be obtained from the lignin-containing black liquor as a byproduct alcohol. Dr. J. MattheuB wants to win fermentable peat dextrose.

On 2/12 1894 it patented (DRP 92079) in Germany the chemist Simons s from Christiania a method for rapid saccharification of cellulosic materials with the help of 0.4-0.8% strength acids at 7 Atm. Pressures and above. The process should be completed in 10-30 minutes. Simonsen won from 1 kg wood 60g Alcohol, ie an over earlier specifications rocht modest yield.

In the spring of 1898 a longer work of the above-mentioned inventor in Germany became known. She was rewarded by the polytechnic clubs to Christiania with a gold medal and through this magazine (II, 195 [1898]) spread, Si monsen experimented on the influence of the I> ruckcs, the amounts of water, the inversion time and the amount of acid in the inversion cellulose-containing materials at. He came with the use of

Sulphite to sugar yields of 45%, but he keeps higher yields for excluded, because the high temperature during the inversion of the cellulose effecting partial decomposition of sugar formed. Unfortunately, he determined the quantity of sugar with Fehling's solution and tried NNR to lead an example to prove that all determined by Fehling see solution was fermentable sugar. In the experiments with sawdust he finds the most advantageous yield at 1/4 constant heating of 100 g sawdust with 500 cc of 0.5% sulfuric acid at 9 atm. Pressure. The fermentation of the resulting sugar tests resulted in only a few attempts to positive results. Here was obtained as a maximum yield of 100 g of sawdust 6.5 cc (5.1 g ds) absolute alcohol.

He comes to the conclusion that wood let be inverted unexpectedly lighter than cellulose; and the experiments appear to confirm that the resulting sugars of cellulose of Holzos entstamme, since sawdust the sugar yield of the corresponding receivable from cellulose of wood acceptance.

On February 15, 1899 the Dr. Alexander Classen from Aachen was the first patent on a Holzverzuckerungsverfahren issued (DRP 118 868). It is strongly pressing a mixture of sawdust and sulfuric acid by 57 ° Be. The mass is heated by itself, is then crushed and boiled with water. A process (DRP 118 540), the yield in the timber inversion by boiling with sulfuric acid and sulfuric acid or sulfurous acid and oxidation by subsequent same increase to sulfuric acid, to him on 24/9 was. 1899 protected. This is followed by three patents of 12 /. 5 1900 (D. R. P. 118 542, 118 543, 118 544). The first is that you heat the wood substances with hydrogen chloride in an autoclave and then importing sulfuric acid to form sulfuric acid. The second patent will the yield of sugar increased due to heating the raw material with sulfur dioxide and then initiates the formation of sulfuric acid chloride. The third patent is that the mixture is heated until the sawdust with sulphurous acid and introduced to their conversion into sulfuric air or oxygen. The introduction of sulfurous acid, the chlorine and air or of oxygen is carried out by all three patents at 120-125 °. - In a patent from the 17th / 10th 1900 (DRP 121 869) is C 1 according to the treat- ment of the wood with patented Sehwefelsäureanhydriddämpfen. For this is the patent of addition 123 911 of 17 / 10th 1900 also imposed on the heating at 125-135 ° subsequent claim.

While Classen will achieve an increase in yield by the addition of sulfur dioxide, looking G entzen and Dr. Roth (DRP 147 844a of 26 / S. 1901) in the ozone yield enhancing agent. If the addition of ozone on the one hand Ligninsubstanzen to fermentable Pro ucts oxidize, on the other hand, the fermentation towards -promoting substances eliminated by oxidation. According to the patent obtained with the use of ozone from 100 kg of pine wood 34 kg fermentable dextrose and from 100 kg of spruce even 40 kg. Man working with 3-4% strength sulfuric or hydrochloric acid, and at a pressure up to 20 atm. The duration of the process is between 10 to 30 minutes.

On 4 /. 9 1904 spoke of Dipl.-Ing. Ripe Scheidt at a meeting of the District Association Saclisen- Anhalt on the production of alcohol from wood waste. He's been through the trials Simonsen see numbers and other individual work, for. Example, the patent of C 1 ate verified. He comes in contrast to P Ayen and consistent with Siracnsen to the conviction that the only alcohol from cellulose tribal, and will assist the lignin in the wood saccharification rather disturbing than a help. He then finds that see ate at the C 1 patents best 8.5-9.5% strength sulfurous acid is applied and the favorable duration of the test is 1 hour; the favorable temperature lies between 140-150 ° at 4-5 atm.

In 1905 (8 / G.) Was the Kaufmann Arno natives of Vienna in England granted a patent for the presentation of sugar from cellulosic materials. It dealt with the raw materials with 5% solutions of caustic alkali at 30-40 ° with a portion of the components, which he called "amyloid-like", goes into T.iösung. By boiling the filtered liquors the "amyloid-like components to pass into sugar.

Let's take a look back at what has been said, we find that the information on the yield of sugar and alcohol very diverge. The highest figures are recorded in the oldest literature; so Braconnot wants from 20.4 g canvas gained 1817 23.3 g sugar. Often confined in the yield details . the term "large quantities" sugar Arnould found in 1854 still 100 g timber 110 g sugar Later, information about the alcohol yield occur, but they are already significantly smaller;. so B asset was 100 g timber 32 cc alcohol, Ludwig 36.6 g (about 41 cc) alcohol. In 1867 Payon 100 g timber 21.3 g sugar and represents the end of 1898 Simonsen60g alcohol from 1 kg wood.

From the foregoing, it is apparent how often you have already dealt with the saccharification of cellulose, and the großen- differences that were included in the yields, are evidence of the ignorance of the most important influences. The only match was probably obtained from Simonsen and of Ripe Scheidt, both received approximately 6 g of alcohol 100 g timber, a yield, which is also confirmed by the present study. Of course, the differences and probably especially the incompleteness of the papers make it difficult to carry out such tests and verification of information significantly.

The arrangement of my experiments was the following generally. The raw material (sawdust, sulphite of H Dele material in Heidenau and straw by Dietrich in Weissenfels) was, according ever and the experiments, shorter or longer Time with dilute or more concentrated sulfuric acid, some with and some without the addition in an approximately 2 1 autoclave heated. The autoclave was lined with lead and copper protected by him heated glass flame through a layer of air, so that the Bunsen flame could effect no direct destruction of the trapped substances. Often has also worked in the water bath. After completion of the cooking, the acidic liquid was filtered off from the solid residue and the first 500 cc for further processing. The filtrate was colored differently according to the type of starting materials, from dark reddish brown to bright orange. So saw filtrates of wood inclusions of maroon, red ones of sulphite and approaches with straw fabric sohön reddish. Allowed to stand in an acidic solution, divorced after a while even the residues of similar masses. Alkalies, the solutions were dark in color, resulting from the sawdust darker than originating from sulfite and these darker back than those of straw fabric. In the first experiments, the sugar content with Fehling's solution by weighing the oxidized copper to cuprous oxide was determined. However, it soon turned out that the calculated from the amount of sugar alcohol is not the obtained by the fermentation same came in all cases, as Simonsen (these Z. 11, 225 [1898]) takes, as two here about employees experiments as 21, 6: 20.0 behaved, so were only 8% difference and you have to expect the distillery process with 10-20% loss.

So I found, for example quite matching values ​​(at least within the limits of the distillery loss) for the following Vorsuchen. Sawdust with 0.5% sulfuric acid inverted (no. 1):

Alcohol calculated from sugar reduction. 5.21 g

by direct fermentation obtained 5.21 g

Sawdust with 0.5% sulfuric acid inverted after previous treatment with water vapors (no. 3):

calculated from the sugar reduction. ,, 7.39 g

directly by fermentation obtained 6.83 g

Sulfite with 0.5% sulfuric acid with the addition of 2% hydrogen peroxide (no. 14) is inverted:

calculated from the reduction in number .... 16.08 g

directly by fermentation 14.64 g

Straw material with 0.5% / sulfuric acid with addition of 2% hydrogen peroxide ^ inverted (no. 15):

from the determined by reduction

Sugar amount charged 8.51 g

directly by fermentation 8.36g

In contrast to these are provisions where the differences are in part very significant:

(No. 2) When addition of S02 showed the inclusion of the experiment no. 1 calculated from the glucose

Amount of alcohol 2.43 g instead of 1.74 g (no. 2), obtained by fermentation, and

Amount of alcohol 9.56 g instead of 5.52 g (no. 6), obtained by fermentation.

Trying '8, in which sulphite easy with 0.5% sulfuric acid at 8 atm. was cooked, gave a liquid whose alcohol yield should be according to the method with Fehling's solution 10.94, and returned from the fermentation only 8.43. Also I got the inverting straw fabric with 0.5% sulfuric acid

8.52 g of the sugar content instead

5.4g in direct fermentation.

These errors are due to other reducing substances here, which are not fermentable sugar; so were in Experiment Nos. 11 even larger amounts of an aldehyde with schwefligsaurer Fuchsin be proven solution that visit proved by red-Scsamöl as furfural. In this experiment the amount of alcohol, calculated from the see through Fehling solution specific sugar content was 7.66 g. While only 2.12 g of alcohol obtained by fermentation. Even Simonsen wants (this Z. 8. 196 [1895]) have odor of furfural observed.

For these reasons, the alcohol was determined directly by fermentation in all experiments, and in the following manner: A portion of the filled to a certain volume filtrate was neutralized with carbonate of lime, displaced from Rückständeabfiltriert, with a few drops of acid and yeast at 25-30 "during two to three days fermented. The fermented liquid of the yeast wTirde separated and distilled off after addition of a little tannin. After about one Thirds had gone over, the distillation was adjusted to offset the distillate blunting about acetic acid formed with little carbonate of lime, and even distilled once to several times (as required). The specif. Weight of the obtained alcohol-containing liquid was always determined at the same temperature with the pycnometer.

1. Comparative experiments on the saccharification of sawdust, straw pulp and sulphite with dilute sulfuric acid.

The question of whether formed by hydrolysis of cellulose from wood sugar entstamme alone, or whether the Ligninsirbstanzen it have proportion, has been much discussed. So took z. B. 1867 P a y c n at. that the sugar arises from the lignin and cellulose would not be attacked because he wanted to get in the big wooden with hydrochloric acid pure cellulose for the manufacture of paper, and thought it to be converted into sugar that incrusting substances. That pure cellulose with sulfuric acid is hydrolyzed, it is clear today, and only the question of whether lignin is transferred into sugar is to answer nocli. So the lignin after the trials of Lindsey appears to have no relations with hexose, because it was not possible from the timber liquid (sulphite) to obtain levulinic acid that occurs very easy from the carbohydrates. If one were to determine lignin seen as no carbohydrate, as well as its inversion would be virtually impossible. - From Simonsens Try to get to the conviction that the resulting in the inversion of sugar comes from only the cellulose as wood 20% sugar, cellulose 45% sugar were obtained, and assuming that wood contains 50% cellulose, which consists of the sugar Holze gained about the receivable from the cellulose of the wood alone would correspond. Since the Simonsen see provisions with Fehling's solution, have been carried out, and this method, as we have seen, is not perfect, so several tests with wood sawdust, sulphite and straw material under the same conditions were carried out by each 40 g in 500 cc of 1 / 2% sulfuric acid 'for two hours 6-8 Atm. and then heated, as mentioned above, were processed further. The yields of alcohol were:

Holzsage- sulfite straw chips cellulose material 5:21% 13.69% 9:56% 6.83% 11.97% Medium 6.02% 12.83% 9.56%

The highest yield gave the sulphite with 12.83 g alcohol on average per 100 g of dry feedstock. It is about twice the yield value for sawdust. Taking the sawdust with 50% cellulose. so the alcohol obtained from the sawdust would correspond to the cellulose of the wood from the receivable alone. The experiments confirmed the Simonsen see details and fortified the view that the sugar entstamme alone the cellulose and the lignin is not convertible into sugar.

To be able to go into more detail on this point, were provisions of Cellulosegehaltesausgeführt, namely for wood and sulphite by the method of Fremyund Terreil (Z. Anal. Chem. 1, 282). The 'Unlocking happens here by 36stündiges standing in chlorinated water. Then the Küekstand is boiled with potash, which is now to solve the non-cellulose substances easily. Finally, we still washed out with dilute acid and dried at 136 °; by weighing in a platinum dish, annealing and reweighing the cellulose is determined.

There were obtained 0.4387 g of cellulose by this method from 0.8804 g of dry wood, and from 0.8749 g 0.4224 g, which would correspond to 49.83 and 48.28%. Even less well-tune the values ​​for sulphite agree among themselves. From 0.9386 g and 0.9617 g 0.7845 g sulphite cellulose obtained, ds 83.598 and 79.693%.

The content of the straw material was cellulose and by the method of Henneberg Determined Wender (Eisner, practice of the chemist in the study of food, p.44). . The method is widely used in food chemistry to determine the "crude fiber", but is not suitable for wood, because the wood was seemingly not dispersed enough, the straw material was, when cooking to a fine slimy mass, and the results were as follows:

Applied substance .... 2.6396 g 3.3728 g

Difference between the weighted at 105 ° cellulose and its ignition residue 1.8241 g 2.3167 g

in% ie 69.18 and 68.69

If you compare the numbers to cellulose yields over, we find the following one:

% Alkoholan

Cellulose yield

Wood 49.05 6.02 (6.02)

Sulphite 81.64 12.83 (10.02)

Straw material 68.90 9.56 (8.46)

The numbers behave superficially proportional. For sulphite and straw material, one can calculate the expected numbers of yields from the cellulose content and the alcohol yields of timber. The figures are included in parentheses. The agreement is a very bad. The reason that the yields are greater in reality is likely to be due to the bad method of cellulose provision which provides for low values.

II. Experiments on the effects of sulfurous acid in the saccharification of wood.

It is widely believed that the sulfurous acid exerts a beneficial effect on the yield of sugar in the wood saccharification. The oldest note in this regard is probably the American patent 654 518 (Chem-Zeitung. 24, 693 [1900]). About the effectiveness of sulfurous acid can be found in the literature are two views:

1. They want the sulfurous acid as the acid needed in the inversion use (in general. Chemikerzeitung 5, 646 NND C 1 ate, DRP 130 980).

2. They want to achieve by pretreatment with sulphurous acid an easier vulnerability of the material and create by oxidation to Schwefe acid by means of air, oxygen or chlorine necessary for the inversion acid. In this direction to move the patents of C1 ate: DRP 118 540, 118 543, 118 544th

First, about twice per 40 g sawdust pretreatment with 2% were fixed Sweet water for two hours at 6-7 atm. subject and cooked it with 0.5% sulfuric acid at the same pressure. The further processing was done, as mentioned above, to give 100 g of dry sawdust 4.16g and 5:52 g alcohol. From this it appears that pretreatment with S02 does not increase, but rather decreases the yield of alcohol as S02 without -Zusatz 6.02 g were obtained.

III. Experiments on the effect of oxidizing agents in the wood saccharification.

The hydrocellulose whose formula we will assume as Ci2H22On (C. 15, I, 933), we can think originated from two molecules of cellulose through intake of one molecule of water ourselves inter alia with the simplest of cellulose formula:

2CeH10O5 + H20 C12H22Ou Cellulose hydrocellulose.

The Kohlenstoffgchalt drops from 44.44 to 42.11%, while the oxygen content of 49.39 to 51.46 and the hydrogen of 6.17 to 6.34% increases. It was now close to the idea that the hydrocellulose much lighter in sugar should be converted, as the cellulose, as they sugar already a molecule is according to their composition of water closer than the cellulose. - The hydrocellulose was prepared according to the directions of U 1 zer (Fischer Wagner, Jahresber of Chemical Technology in 1905, II, 192).,

With 40 grams of this hydrocellulose a boiling with 500 Cera 0.5% sulfuric acid for about 3 hours at 153 to 160.5 ° run. The further work was done, as just stated, and there were 100 g dry hydrocellulose IT, received 95 g of alcohol.

The figure is the highest obtained by me yield.

There were obtained as averages of:

Wood 6.02% alcohol

Straw fabric 9.56%

Sulphite 12.83%

Hydrocellulose .... 17,95%

Now it has been attempted temporarily to achieve by adding oxidizing agents from the starting materials of hydrocellulose like substances, which would increase the yield analogous to the good yield of pure hydrocellulose. The addition of oxidizing agents to hydrocellulose decreased the yield, such. As the addition of 2% hydrogen peroxide at 11.12%, with chromic acid even at 3.95%.

A. additions of hydrogen peroxide to inclusions of celluloseh AltiGen substances and 0.5% sulfuric acid.

There are three approaches in each 40 g sawdust, sulphite, straw fabric with 500 cc of 2% hydrogen peroxide and 2.5 g of concentrated sulfuric acid (ie so that a 0.5% acid was present), during three hours at 7,4- 9 atm. heated to 163-166 °,

After the open for a few minutes yet was boiled and then, as stated above, further work ge: it arose following increased yields:

with inversion added

without the addition of 2% H202

Wood 6.02 9.05 u. 10.76

Sulphite 12.38 14.64

Straw fabric 9.56 10:26

When wood is increasing, which is caused by Wasserstoffsuperoxydzusatz, greatest, and of straw fabric at its lowest.

B. Experiments with potassium chromate as an oxidant.

Since the same amount of oxygen, as in the experiments should be used with hydrogen peroxide, so I sat each batch of 28.8 g and 38.4 g of potassium bichromsaures sulfuric acid (500% com 2 H202 H202 contains 10 g or 4.7 g of active oxygen, the same amount delivers quantity referred biehromsaures potassium).

The harmful effects of chromium compounds on the yeast was removed by precipitation with lime prior to fermentation.

The 40 g sawdust, straw or sulphite pulp were in the same circumstances for 3 hours at 7.4 to 8.7 atm. heated. After the open was the light green solution, as mentioned above, further processed.

Yields resorted to inversion

with the addition of

without blohrom saurein

Additional potassium and

sulfuric acid

Wood 6.02 3.23

Sulphite 12.38 2.34

Straw fabric 9,56 3,23.

The action of potassium dichromate reduced by preceding experiments, the alcohol yield significantly.

C. Experiments with potassium persulfate as an oxidizing agent.

The potassium provides the decay according to the formula:

K2S208 = K2S04 + S02 + 02

Thus 270 g of potassium persulfate 32 g of active oxygen. In order to get the same amount of active oxygen as in the experiments with hydrogen peroxide and potassium chromate, 40.7 g of potassium persulfate were necessary.

It parallel experiments with 40 g wood sawdust, straw and sulphite pulp were carried out, which could be calculated as yields below numbers.

for inclusion * eÄa'z

without adding "^ HS *

Wood 6.02 4.22

Sulphite 12.38 7.32

Straw fabric 9.56 2.57

After the addition of potassium persulfate so the yield dropped significantly during the saccharification of applied oellulosehaltigen raw materials.

D. addition of ozone to the inclusions in the wood saccharification.

From Dr. Roth and R. Gentzen was to increase the sugar yield in the saccharification of sawdust ozone propose measures as an oxidizing agent and the method by DRP 147 844a protected. The patent is explicitly mentioned that the ozone causing the oxidation of lignin in the sugar sector by separating the fermentation-inhibiting substances by oxidation. Striking is the assertion that the inkrust ierenden body are carbohydrates very close, while JB Lindscy (Inaugural Dissertation, Göttingen 1891) explicitly stated that he had obtained from the lignin-sulphite of Sulfitcellulosefabriken only small amounts of levulinic acid and according to the investigations of Wehnet (Lieb. Ann. 343, 333) the emergence of levulinic acid is an undoubted sign of the counter-presence of carbohydrates. The patents after the ozone is under 3-4 atm. Pressure for 10-30 minutes supplied to the raw material, and then boiled with 3% sulfuric acid. Information on concentration of ozone are completely absent; also the information on the execution of the process are very deficient. It can be found just a few notes on yield, for example, should be obtained from 100 kg of pine wood 34 kg fermentable dextrose. these are at a level of 50% cellulose, 61.2% yield, with spruce wood and straw, they are given even higher.

There were of me first two attempts of any ozone content performed at an exposure time of 25-30 minutes. The first process was carried out in the heat, the latter in the cold. The introduction of ozone happened at ordinary pressure because my equipment to Overcome 2-4 Atm. were not available. The alcohol yield was in the former case, 1.5 g of 100 g of dry sawdust and the second attempts 4.1g; So always lower than with simple cooking with sulfuric acid.

The following experiment joins the Patent closer to, 40 g sawdust with 15% water content were exposed to 20 minutes a 2% ozone stream it in 3% sulfuric acid for 1 hour at 4-5 atm. heated. 200 cc of the filled to 600 cc of the filtrate gave spec during the fermentation 105 cem alcoholic distillate from. Resulting in calculated on 100 g dry wood alcohol 4.72 wt. 0.99903.

Two experiments were carried out with 6% ozone for 21 / i hour. The sawdust were wetted with three times the amount of water and placed in a U-tube, so that the stream of ozone was passed across it.

Two further experiments were performed with 0.7% ozone by the action period of 10 'and 30'. Another 1.8% ozone at one hour exposure. The results are illustrated in the table below.

Unfortunately, for the presentation of ozone only after several changes see a iialbwegs useful apparatus in the Berthelot tube found, but here was a complete uniformity of the ozone stream can not be achieved, so that the provisions of 03 quantities turned out very inaccurate; But in comparison with these values ​​can be clearly seen that the quantity of sugar decreases with increasing amount of ozone.

Consider the following tests: !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! No. DdOaeuserr- Effect Spent LiOitenrjn % O "So Oa "O N 51 10 ' O 0.7 14 cem 6.61 = 45 20 '4 2.0 80 4.7 cem 53 30 '7 0.7 49 5.78 cem 55 60 '13 1.8 234 0.6 cem 47 135 '35 5.5 0.35 1925 cem !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
 * c_

From these figures it can be seen how the alcohol yield in proportion of the reduced amount of ozone. A part of ozone is determined by the heat at which the initiation takes place, is, have been destroyed, yet the adverse effect of ozone is still very visible. After 10 minutes (51) strength stream of ozone and 50 ° no harmful exposure was recorded at 0.7%. However, the yield dropped already at 30 minute duration of 0.7% ozone stream. When applying the stronger 2% igon ozone stream already after 20 minutes a significantly greater difference can be seen, since the amount of ozone has risen to 80 cc. Analogous to the rise in the amount of ozone, the alcohol yield drops to 0.35 g per 100 g of wood. - To determine how the 03- action on sulphite Am working the following experiment was recognized.

40 g sulphite of 9.5% water content were wetted with 150 cc of water and exposed for one hour a stream of ozone of 1.81% Os, at a water temperature of 39 °. Then the sulphite cellulose was boiled for one hour at 155-160 ° with 300 cc of 3% sulfuric acid. The fermentation yielded so little alcohol that to 100 g dry sulphite calculated 1:42 g alcohol.

The ozone thus acts harmful even at Sulfitcellulosekochung.

Summary of the results obtained.

In the comparative experiments on the saccharification of cellulose raw materials, the wood, the oxygen and the specified sulphite of Simonsen yield of 6 g of alcohol, 100 g of dry wood has been confirmed by two tests. The largest yield of alcohol resulted in the percentage of the highest cellulose content owning sulphite with an average of 12.83 g alcohol 100 g starting material. This is twice the amount of the receivable from wood alcohol. Since the wood contains approximately 50% cellulose, which seems an unmistakable evidence that the resulting sugar originates from the cellulose and lignin not as assumed ayen P, and it is believed still often today.

The additions of sulfur dioxide proved contrary to what the patents of C1 ate - Aachen, when the saccharification hindrance; not even in a single attempts satisfactory results were obtained.

The addition of oxidizing agents to the inclusions reduced in most cases, the formation of sugar; could stoffsuperoxyd only the addition of water has a higher yield can be achieved; when a wood to 50% of otherwise receivable amount of alcohol amount end gain. For this result, one can conclude that weak Oxidant convert the cellulose into one of the saccharification more oblique connection. Since the yield of alcohol from hydrocellulose reached the maximum value of 17.95%, so the conclusion is obvious that daa peroxide converts the cellulose in hydrocellulose, and this is due to the greater Zuekerbildung. The other applied Oxydationszusätze how the potassium dichromate, potassium persulfate and the ozone, are powerful agents; they oxidize the cellulose on the hydrocellulose away to other substances.

The product covered by the patent from Dr. Roth and Gentzen addition of ozone resulted in the complete opposite of the set up there assertion by ozone addition resulted in a reduction of fermentable sugars. The decrease in yield was carried out fairly proportional to the supplied amounts of ozone.

In general, therefore, the yield of alcohol by hydrolysis of wood is quite low, considering that theoretically 100 g Cellulose 56.91 g alcohol may arise; because even at best, no more than 25% of the calculated amount of alcohol has been achieved in a simple hydrolysis. It is therefore natural to assume that from the cellulose complex (CgHi0Os) x split only a part and in fermentable sugars can be converted.

Scientific American Supplement No. 1736. April 10, 7909
PRODUCTION OF ALCOHOL FROM CELLULOSE. HOW WOOD AND WOOD PRODUCTS MAY BE EMPLOYED. BY TH. KOERNER.

The idea of obtaining alcohol from wood is not new. In 1819 Braconnot published a method of converting woody fiber into fermentable sugar. The wood was first treated with cold concentrated sulphuric acid, which caused a great elevation of temperature and an evolution of sulphur dioxide. Water was then added, the mixture was filtered and the filtrate was neutralized with chalk. A gummy mass was thus precipitated which was converted into fermentable sugar by the action of dilute sulphuric acid. In the following year Vogel repeated Braconnot's experiments and extended them to paper, cotton, straw and cork. In 1854 Arnould claimed to have converted from 80 to 90 per cent of wood into soluble products by treating it with rather more than its own weight of strong sulphuric acid. In 1855 Melsens substituted treatment with weak acid (3 to 5 per cent) in a digester at temperatures up to 350 deg. F. A factory for the production of alcohol from wood was started in Paris in 1855, but it does not appear to have existed many years. In Geneva, some years later, an attempt was made to produce alcohol, on a commercial scale, from residues of wood left in paper making.

In 1867 Payen claimed to have obtained alcohol from the lignin contained in the wastes of the manufacture of paper, and Matthews claimed to have obtained fermentable dextrose from peat.

In 1894 the Norwegian chemist Simonsen patented, in Germany, a process for the rapid saccharification of substances containing cellulose by treatment with weak acids (4/10 to 8/10 per cent) under a pressure of 7 atmospheres or more. The process occupied from 10 to 30 minutes. A kilogramme of wood yielded 60 grammes of alcohol—that is to say, the yield was 6 per cent, which was very small in comparison with earlier claims.

In 1898 Simonsen published the results of experiments on the influence of pressure, time, and the quantities of water and acid employed in the inversion of substances containing cellulose. From sulphite-cellulose he obtained 45 per cent of sugar, which he regarded as the maximum yield, because part of the sugar formed is destroyed by the heat of the reaction. He estimated the sugar by Fehling's method and assumed, after a single test, that all of it was fermentable. With sawdust he obtained the best yield by heating the sawdust 15 minutes with five times its weight of V- per cent sulphuric acid, under a pressure of 9 atmospheres, but few experiments in fermenting the sugar gave positive results. The highest yield of absolute alcohol was about 5 per cent of the weight of sawdust. Simonsen concluded that wood could be inverted more easily than pure cellulose, but that all sugar came from the cellulose of the wood.

In 1899 Classen patented a process in which saw dust, is mixed with sulphuric acid of 57 deg. Baume and subjected to great pressure. The pressed mass is then broken up and boiled with water. In other patents of the same year he claimed the employment of sulphurous acid, alone or In conjunction with sulphuric acid, or with chlorine, air, or oxygen. In the following year he patented the treatment of wood with vapor of sulphuric anhydride.

In 1901 Gentzen and Roth patented the employment of ozone for the purpose of converting lignin into fermentable sugar and destroying substances which prevent fermentation. The patentees claimed to have obtained from 34 to 40 per cent of dextrose from pine and fir wood. They used 3 or 4 per cent sulphuric or hydrochloric acid under a pressure of 20 atmospheres. The process occupied from 10 to 30 minutes.

In 1904 Reiferscheidt reviewed the subject experimentally and concluded, with Simonsen, that the cellulose of wood is the sole source of sugar and that the presence of lignin rather obstructs the process of saccharification. In experimenting with Classen's processes he obtained the best result by treating the material one hour with 9 per cent sulphurous acid at a pressure of 4 or 5 atmospheres and a temperature of nearly 300 deg. F.

In 1905 Boernen obtained an English patent for a process employing 5 per cent solutions of caustic alkalies at about 90 deg. P., and boiling the liquid after the unaffected residue of the wood has been removed by filtration.

It appears from this historical sketch that the estimates of the yield of sugar and alcohol differ very greatly. The oldest estimates are the highest. Braconnot claimed to have obtained from lignin more than an equal weight of sugar, and Arnould made a similar claim in regard to wood. Often the yield is given simply as "very large." The later claims include alcohol and also become more modest until, in 1898, Simonsen obtains only 6 per cent of alcohol, a result confirmed by Reiferscheidt in 1904, and also by my own experiments.

In general, I operated as follows: Sawdust, sulphite cellulose, or straw was digested for a longer or shorter time with dilute or concentrated sulphuric acid, with or without other reagents. The digester was of copper, lined with lead, and held about two quarts. It was heated on a water bath or by a Bunsen flame which was not in contact with it. The acid solution obtained by this process was filtered. The color of the filtrate was red, orange or brown, and was darkened by the addition of alkalies. In the first experiments the sugar was calculated from the weight of cuprous oxide produced by treating the liquid with Fehling's solution, but I soon discovered that the amount of alcohol which corresponded to the quantity of sugar thus found did not always agree with the amount of alcohol obtained by actual fermentation and distillation. In some cases, the difference was less and in others much greater than the unavoidable loss in distillation (which is from 10 to 20 per cent), as appears from the following table:

, Percentage, of Alcohol. Raw Material. Reagent and Calculated Obtained 1> Process. from Cuprous Distillation. Oxide. Sawdust. % per cent sulphuric acid 5.2 5.2 Sawdust. y2 per cent after steam ing 7.4 6.8 Sulphite cellulose. % per cent, with 2 per cent 4iydrogen di oxide 16.1 14.6 Straw. V-j per cent, with 2 per cent hydrogen dioxide 8.5 8.4 Sawdust. % per cent, with sul phurous acid 2.4 1.7 Sawdust. '/_. per cent, with sul phurous acid 9.6 5.5 Sulphite cellulose. % per cent at 8 atmospheres 10.9 8.4 Straw. % per cent "8.5 5.4

The great difference between the calculated and the real percentage of alcohol in the last four experiments is due to the presence of reducing substances, other than sugar. In another experiment, in which the calculated percentage of alcohol was 7.7 and the real percentage only 2.1, the presence of a large quantity of furfurol was discovered. Simonsen also detected furfurol by its odor.

For these reasons the quantity of alcohol was always determined directly. Part of the filtrate from the digester was neutralized with chalk, again filtered, acidified with a few drops of phosphoric acid and fermented with yeast for two or three days at about 80 deg. F. The fermented liquid was freed from yeast and distilled after a little tannin had been added. When a third of the liquid had passed over the operation was stopped and the distillate was mixed with a little chalk for the purpose of neutralizing any acetic acid that might have been formed, and redistilled one or more times, according to its strength. The specific gravity of the final product was always measured at the same temperature, with the pyknometer.

A series of experiments was made In order to determine whether sugar can be obtained from lignin as well as from cellulose. Simonsen's experiments appeared to prove that the sugar was derived entirely from the cellulose, as be obtained 45 per cent of sugar from pure cellulose but only 20 per cent from wood containing 50 per cent of cellulose. But he estimated the sugar by Fehling's method which, as we have seen, is unreliable. Hence I made comparative experiments with equal quantities of sawdust, sulphite cellulose and straw, digesting each with about twelve times Its weight of per cent sulphuric acid at a pressure of 6 or 8 atmospheres for 2 hours, and then fermenting and distilling as described above. The percentages of alcohol obtained were:

From From sawdust. sulphite cellulose. From straw s' 13.7 9.6 6.8 12.0 Mean 6.0 12.8 9.6

The yield from cellulose was about twice that from sawdust. Assuming that the sawdust was half cellulose, this result confirms the theory that all of the sugar is derived from the cellulose and none from the lignin of the sawdust. In order to attain certainty on this point the cellulose content of wood and of sulphite cellulose was determined by the method of Fremy and Terrell. The wood (or sulphite cellulose) was steeped in chlorine water for 36 hours and then boiled with potash, which dissolved most of the other ingredients, leaving a residue of nearly pure cellulose, which was washed with dilute acid, dried, weighed on a platinum dish, and incinerated. The dish and ash were then weighed. The difference between the two weights was taken as the weight of cellulose. Two specimens of dry wood thus yielded 49.8 and 48.3 per cent of cellulose, while two specimens of sulphite cellulose yielded 83.6 and 79.7 percent of pure cellulose. The cellulose content of straw was determined by the method of Henneberg and Wender. Two specimens yielded 69.2 and 68.7 per cent of cellulose.

The mean percentages of cellulose and alcohol are approximately proportional, as shown below:

Cellulose. Alcohol. Wood 49.0 6.0 Sulphite cellulose 81.6 12.8 Straw 68.9 9.6

Two experiments were made to determine the effect of sulphurous acid. Sawdust was digested, first with 2 per cent sulphurous acid, and then with \i, per cent sulphuric acid. 4.2 and 5.5 per. cent of alcohol were obtained. As sawdust digested with sulphuric acid alone yielded 6 per cent of alcohol, the preliminary treatment with sulphurous acid is worse than useless. The substance known as hydrocellulose, which may be represented by the formula C,.H= O,,. may be regarded as formed by the combination of two molecules of cellulose (assuming the simplest possible formula for the latter) with one molecule of water: 2C6H10O5 + H20 = C12H22. As hydrocellulose (like cane sugar, which has the same empirical formula) stands midway between cellulose C6H10O5 and glucose C6H12O6 which differ by a whole molecule of water (H2O), it appeared likely that sugar could be obtained more readily from hydrocellulose than from cellulose. I digested hydrocellulose (prepared by Ulzer's method) with 12 times its weight of % per cent sulphuric acid at about 315 deg. F. for three hours, and obtained, by fermentation and distillation, 18.0 per cent of alcohol. This is by far the highest yield obtained from any material, as appears from the following table of mean results :

Per Cent of Alcohol. Wood yielded CO Straw yielded 9.6 Sulphite cellulose yielded 12.8 Hydrocellulose yielded 18.0

I then attempted to produce hydrocellulose or similar compounds by oxidizing wood, etc., during the process of saccharification, although the alcohol yielded by hydrocellulose itself was found to be diminished from 18 to 11 per cent by the addition of hydrogen dioxide, and to 4 per cent by the addition of chromic acid.

Equal quantities of sawdust, sulphite cellulose, and straw were digested 3 hours at about 8 atmospheres and 328 deg F with water containing 2 per cent of hydrogen dioxide and 1/2 per cent of sulphuric acid. The percentages of alcohol compare as follows with those obtained with sulphuric acid alone:

Without Hydrogen With Hydrogen Dioxide. Dioxide. Wood 6.0 9.9 Sulphite cellulose 12.8 14.6 Straw 9.6 10.3

Hence it appears that hydrogen dioxide increases the yield of alcohol, especially from wood.

In another series of experiments the hydrogen dioxide was replaced by an equivalent quantity of potassium bichromate, the injurious action of the chromium compounds on the yeast being prevented by precipitation with lime before fermentation. The addition of the bichromate greatly diminishes the yield of alcohol in all cases, as appears from the following table:

Without With Bichromate. Bichromate. Wood 6.0 3.2 Sulphite cellulose 12.8 2.3 Straw 9.6 3.2

In another series an equivalent amount of potassium persulphate was substituted for the bichromate, with similar results:

Without With Persulphate. Persulphate.. Wood 6.0 4.2 Sulphite cellulose 12.8 7.3 Straw 9.6 2.6

Roth and Gentzen In the application for their patent covering the employment of ozone in the saccharifleation of sawdust assert that ozone not only promotes fermentation but also converts lignin into sugar. They also assert that the substances associated with cellulose in wood are very similar to carbohydrates, but although the sulphite liquor of cellulose factories employing the sulphite process contains a great deal of lignin Lindsey could obtain from it only small quantities of levulinic acid, the production of which, according to Wehner, is a certain proof of the presence of carbohydrates. I treated sawdust with increasing quantities of ozone and then digested it with 3 per cent sulphuric acid (the strength recommended in the patent). The alcohol obtained decreased steadily from 6.6 per cent to 1/3 per cent, the decrease being nearly proportional to the quantity of ozone employed. Similar results were obtained with sulphite cellulose.

SUMMARY.

For wood my results agree with those of Simonsen and give a yield of absolute alcohol equal to 6 per cent of the weight of dry wood. Sulphite cellulose contains about twice as much pure cellulose as dry wood contains, and yields about twice as much alcohol. This proves that the sugar which is converted into alcohol is derived from cellulose and not at all from lignin. The addition of sulphurous acid, recommended by Classen, diminishes the yield of alcohol in all cases. The yield of alcohol is increased by hydrogen dioxide but diminished by stronger oxidizing agents. These results suggest that hydrogen dioxide converts the cellulose into hydrocellulose, which I found to yield a very high percentage of alcohol, but that the stronger agents oxidize the cellulose to a higher stage, producing non-saccharifiable compounds.

The employment of ozone recommended by Roth and Gentzen diminishes the yield of alcohol in proportion to the quantity of ozone used.

The actual yield of alcohol from wood, 6 per cent, Is less than one-quarter of the theoretical yield, for wood is nearly half cellulose, and cellulose, theoretically, should yield 56.91 per cent of alcohol. This great disparity suggests the hypothesis that a portion of the complex cellulose molecule (C„H,„On), is split off and converted into sugar.

Condensed from Zeitschrift fuer Angewandte Chemie

SCIENTIFIC AMERICAN SUPPLEMENT No. 1789. APRIL 16, 1910.
ALCOHOL FROM"WOOD WASTE.* ITS CHEMISTRY AND PROCESSES. BY PROF. R. F. RUTTAN, M. D.

The action of the zymase of yeast upon glucose and certain other fermentable sugars is the one source of the ethyl alcohol of commerce. It therefore follows that the problem of how to produce ethyl alcohol in a more economic manner can only be solved by finding a new and cheaper method of obtaining solutions of fermentable sugars.

The fermentable sugars employed in the preparation of alcohol have been derived hitherto from a number of sources, which may be generally stated to be (1) the products of the hydrolysis of starch and allied substances by means of an amylase; (2) solutions of sugar obtained directly from fruits, etc., and the noncrystallizable by-products of sugar works, etc.

The cost of alcohol from these sources is much too great to enable it to compete with other products in many fields where it could be used to great advantage. This is due, not so much to the cost of manufacture as to the cost of the raw material from which the fermentable sugar is obtained. The most economical source of starch on this continent is Indian corn, yet this raw material costs at present $21.60 per ton. One ton of corn gives about 90 gallons of alcohol of 94 per cent at a cost of 24 cents per gallon for raw material. About two gallons of raw molasses produce 1 gallon of 94 per cent alcohol, and this raw material costs 21—22 cents. The raw material of German alcohol has been estimated to cost 20 to 21 cents per gallon of alcohol of this strength.

There is a process in which a waste product of nominal commercial value is the raw material from which fermentable sugars can be obtained. The actual cost of sawdust and other wood waste to any industry is difficult to estimate. In some localities, where the quantity of waste is not great, a local market for it has been established, and in most forms it has been disposed of at a small profit. The larger mills, now that electricity is of such general application, have in many cases increased their power and find an economic outlet for all forms of wood waste as fuel for generating this power. There remains, however, the great majority of the large sawmills of this continent where the wood waste has either to be disposed of by sawdust burners at a cost of about 20 cents per ton, or allowed to accumulate in heaps upon the land, or is turned into an adjoining stream to be a nuisance and an injury for many years, if not for generations.

Any industry employing wood waste situated in the vicinity of a large mill of the ‘last-mentioned class, should be able to obtain waste for the cost of transportation and handling which under moderately favorable conditions should not exceed 30—50 cents per ton

As I shall later explain, one ton of sawdust or other comminuted wood waste calculated to a dry basis can be made to yield about 20 gallons of alcohol of 94 per cent. This then reduces the cost of raw material from 20—24 cents to 2 or 2%» cents per gallon of alcohol.

That fermentable sugar can be produced from wood has been known to chemists for nearly a century. Braconnot as early as 1819, by heating wood cellulose with sulphuric acid, produced a pulp which contained glucose. The sulphuric acid, however, could not be economically removed. Since then no process has been devised until quite recently for hydrolyzing cellulose and ‘allied bodies economically.

Numerous attempts have been made to solve this problem and the list of patents on the subject is a large one. Prior to 1900, when the Classen patents were taken out, the hydrolyzing effect of many acids on starch and the celluloses had been studied and the process patented. C. Pope, for instance, in 1898 obtained a patent for hydrolyzing starch and obtaining fermentable sugar by sulphuric acid, and Einar Simonsen in 1898 a patent to make sugar glucose from sawdust by the action of dilute sulphuric acid. Sulphurous acid had long been used to make wood pulp from comminuted wood before these patents; it was also well known that when sulphurous acid was heated with wood, sulphuric acid was always formed which took part in the reaction, and its action was prevented in pulp-making by the use of calcium bisulphite, the sulphuric acid combining with the calcium as it was produced.

Dr. Alexander Classen of the Polytechnic School of Aachen, stated in 1900 that sulphurous acid in aqueous solution under pressure converted the cellulose of wood into glucose and that the product could be fermented in the usual way yielding ethyl alcohol. He patented this process all over the world, but the original methods as stated in the patent proved to be crude and unworkable. The claim is as follows:

“The process of converting cellulose into sugar, which consists in heating the cellulose in a closed vessel at a temperature of 120 deg—145 deg. C. with a solution of sulphurous and sulphuric acids substantially as described."

After successful experiments in a test plant erected by Classen in Aachen, a similar plant on a larger scale was erected at Highland Park near Chicago, to demonstrate to American capitalists its possibilities. The results were so satisfactory that a. larger plant on a commercial scale was erected at Hattiesburg, Miss. The plant included the following elements:

1. An acid apparatus where the solution of sulphurous acid was prepared and where the excess of sulphur dioxide after use could be re-absorbed and saved for further utilization.

2. A revolving cylinder. 30 feet long, and about 36 inches in diameter, which formed the converter or digester.

3. An exhausting battery consisting of a series of tanks in which the sugar was washed from the partly converted sawdust by hot water.

4. Neutralizing vats in which the various acids remaining in the saccharine liquid were neutralized by calcium carbonate.

5. Fermentation vats, and a still, where the process was completed as in an ordinary distillery.

The wood waste was introduced into the digester (which it nearly, but not completely filled), made of iron lined with lead to prevent action of the sulphuric acid, and surrounded by a steam jacket by which it was heated. This revolving cylinder had a capacity of about two tons. To the charge of wood waste was added a weight of a nearly saturated solution of sulphur dioxide corresponding to about one-third of the raw material. The drum was closed air-tight and steam turned into the jacket while the whole slowly revolved. The temperature of the interior was thus slowly raised to 290 deg—300 deg. F., and the pressure to about one hundred pounds. After from four to six hours the sulphurous acid and steam were blown off into the absorbing tanks and the sulphur dioxide thus partially recovered. The cover was removed and the contents emptied looking then very like finely ground coffee. This finely divided, treated wood was conveyed to the exhaustion batteries and the sugar extracted. The liquid obtained, contained from 350—400 pounds of sugar for each ton of raw material treated. The next steps were to neutralize the acid liquid, allow it to clear by subsidence, pump it into the fermentation vats, ferment it by yeast and distill the product in the usual way. It was claimed for the process that each ton of wood waste gave about 18—20 gallons of absolute alcohol.

The history of the original Classen process is an excellent example of how a process which will give very good results on a laboratory scale, will just fall to succeed when magnified to a size necessary for working on a commercial basis. Even the strongest supporters of the original Classen process do not now believe it to be a success as a money-making proposition.

The difficulties in the way to sucess for this process are explained to be: (1) The length of time necessary to convert 11,1, to 2 tons of wood. this requiring from four to six hours; (2) the quantity of acid required; (3) the prolonged action of so much acid and water in the rotating converter reduced the wood to a very fine powder and formed much sulphuric acid which, acting on the sugar and other substances, produced gums and caramels, and so made the complete extraction of the sugar from the residue very tedious and expensive. (4) The buckling and breaking of the lead lining of the converter which had to be repaired after every two or three operations, and proved a very great source of delay and expense.

The plant built in the United States, which is reported to have cost for building and working for a year about $250,000, has not been used for some time. Two chemical engineers, Malcolm F. Ewen and G. H. Tomlinson, who were associated with the Classen process, both in Germany and the United States, finding the original process unlikely to prove a commercial success, obtained substantial financial aid from a Chicago engineer, Mr. J. M. Ewen, and in 1904 began experimenting along new lines to overcome the difficulties which prevented the old process from being a success. The result of their researches and experiments has been to shorten the time of the hydrolysis in the converter from six hours to 40 or 45 minutes, to obtain the treated wood waste in a form which could be quickly and efficiently extracted, to devise a converter which is not in the least degree affected by the process, to reduce the quantity of acid employed, and to obtain a very uniform and large yield of fermentable sugar from wood waste.

This process, by the courtesy of the patentees, l was enabled to study in June, 1909, at Chicago Heights, about 20 miles from the city of Chicago. The plant was erected by the Wood Waste Products Company. now called the Standard Alcohol Company, which has control of the Ewen-Tomlinson patents. This experimental plant was composed of units of commercial capacity, and was set up in workshops in the grounds of a large machinery manufactory. It consisted of the same elements as those required for the older process, viz., the acid generating and recovery apparatus, a converter or digester, a battery of diffusion cells to extract the sugar, neutralizing and storage tanks, fermentation vats, and a distillery.

The converter in use at Chicago was a revolving cylinder, 12 feet by 8, of steel, lined with fire-brick, and set in cement of lead oxide and glycerin. it had a capacity of about two tons of shavings or three of sawdust. The wood waste, sawdust, shavings, or small chips, are dumped into the converter, which is completely filled, and is then closed air tight. Gaseous sulphur dioxide in measured quantity, only about 1 per cent by weight of the dry wood, is introduced through a perforated tube passing through the trunnions of the cylinder and thus through the center bf the revolving mass of the sawdust. When the required quantity has been added the sulphur dioxide is turned oil and live steam is introduced through the same tube till a pressure of about 100 pounds is reached. It takes from 10 to 15 minutes to get the contents of the digester heated up to the required temperature. ‘The steam is then cut off and the digester revolves slowly for another 40 to 45 minutes, the temperature and pressure being kept constant, when the hydrolysis is complete. The steam, carrying with it the terpenes, the excess of sulphur dioxide and some acetic acid, is then discharged into the absorption tank. The manhole is again opened and the coffee-colored chips and sawdust discharged into a V shaped bin which supplies the conveyors going to the diffusion cells.

In the plant now being built for the Du Pont Powder Company at Georgetown, S. C., it is probable that there will be three or four converters, egg-shaped or spherical, and capable of taking four to five tons at one charge. These are to be so arranged that when the digestion in one is completed the steam and acid may be directly discharged into a second digester already filled with wood waste, thus saving time and expense in recovering the acid of each charge.

From the converter the treated wood is conveyed to the extraction battery, where it is rapidly and effectively exhausted by hot water, the acid liquid neutralized with slaked lime and carbonate, allowed to settle in the settling tank, and then pumped to the distillery, fermented and distilled.

in the tests that I made of the plant two charges of the converter were used. The first contained 3,623 pounds of shavings from Chicago mills, air dry and almost entirely pine. This carried 18.61 per cent of moisture, making the dry wood equivalent to 2948.8 pounds. The second charge consisted of 2,992 pounds of shavings and 2,105 pounds of wet hardwood sawdust, consisting chiefly of oak, but with some pine. The total weight of the second charge was 5,097 pounds, with a dry wood equivalent to 3,058 pounds. This second charge was made with a view of testing the effect of the process on sawdust carrying a very high percentage of moisture. The sawdust gave on analysis 70.4 per cent moisture.

The product of the action of steam and sulphur dioxide on the first charge of shavings was a friable‘ brown product resembling tan bark or coffee, with a fragrant aromatic odor and strongly acid. Analysis of this gave:

Per cent. Moisture. . . . . . . . . . . . . . . . . . .......32.23 Total reducing sugars. . . . . . . . . . . . . . . . . . 13.70 Calculated to dry basis. . . . . . . . . . . . . . . . . . . . . . . 20.20 Total acidity (as sulphuric acid, SO.). . . . . . 1.23 Sulphuric acid (80,). . . . . . . . . . . . . . . . . . . . . . . . 0.418 Reducing sugars. fermented. . . . . . . . . . . . . . . . 10.70 Unfermented sugars; xylose, etc. . . . . . . . . . . . . . . 3.00

The wood waste in the second charge after treatment resembled the heated shavings, but was liner and had a powerful aromatic odor and gave the following results:

Moisture. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 34.63<BR> Total reducing sugars. . . . . . . . . . . . . . . . . . . . . .. 14.28<BR> Calculated to dry basis. . . . . . . . . . . . . . . . . . . . . .. 24.18<BR> Total acidity. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 1.12<BR> Sulphuric acid. . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 0.353<BR> Reducing sugars, fermented. . . . . . . . . . . . . . .. 10.97<BR> Non-fermented matter, xylose, etc. . . . . . . . . . .. 3.21<BR>

The total weight of waste wood in the form of saw dust and shavings in these two charges was 8,760 pounds. or calculated to a dry basis, 6,007.1 pounds.

The treated wood was then exhausted with hot water in the extraction battery. The liquid containing the sugar from these two charges was collected in one storage tank and occupied a volume of 2,984 gallons, or 26, 150 pounds in weight. The mingled liquors contained 5.6 per cent of reducing sugars calculated to dextrose.

The total acidity was 0.64 per cent calculated to sulphuric acid. of this 0.21 per cent was sulphuric acid and-the balance was composed of acetic acid, a little sulphurous acid, and aromatic compounds of the type of pyrogallol. The presence of the polyphenols and tannin bodies was most obvious. On neutralizing this solution with lime and calcium carbonate it. blackened rapidly, and when ready for fermentation had an inky color due to the oxidation of the aromatic salts. The liquid also contained a considerable amount of furfurol. As there is little or no nitrogenous material suitable for yeast food in the liquor it does not ferment well alone. hence before adding the yeast about half a bushel of malt sprouts was added to a vat of 3,000 gallons as food for the yeast.

In this experimental plant various forms of yeast have been tried. The problem as to which particular breed of yeast will give the best results was, in June last, still unsolved. The yeast used in my experiment was brewers’ yeast from a neighboring lager beer brewery, which was found to give constant and regular fermentations, but not more than 75 or 80 per cent of the theoretical yield of alcohol was obtained. The fermentation occupied about three days, when the liquid was handed over to the gager and distiller, who was an employee of the United States Government, and placed in charge oi’ the distillery. From the 2,984 gallons of fermented fluid, corresponding to 6,007.1 pounds of dry wood the gager reported 115.92 gallons of proof spirit or 61.06 gallons of 95 per cent alcohol.

This will be seen to be equivalent to 20.55 gallons per ton of wood waste calculated to a dry basis, or 14.14 gallons per ton of wood waste, including the wet sawdust, which contained over 70 per cent of moisture. This alcohol when rectified to 94 per cent is of a potable spirit, crystal white, and carries no trace of odor or flavor of wood. It contains no trace of methyl alcohol or of the higher alcohols such as fusel oil, but gives the reaction for traces of furfurol and aldehyde.

At present there has been little or nothing done toward utilizing or indeed determining the quantity and value of the by-products resulting from the manufacture of ethyl alcohol by this process. The Standard Alcohol Company has contented itself with manufacturing a very cheap and pure ethyl alcohol and has left the working out of the by-products to the future.

The wood waste left behind after complete extraction is a friable cellulose and represents about 65 per cent of the original wood. of which only about one-third is rendered soluble and extracted by the process. This material, according to the present plan, is to be squeezed between rollers, dried partly by waste heat from the boilers and used as fuel. Turpentine and acetic acid are found in the absorption tanks after blowing in the steam from the converter and will no doubt be recovered.

In France there is in operation another process for the manufacture of ethyl alcohol from wood waste. I know nothing of this process beyond an account of it which appeared in the General Electric Review of September, 1909, by G. U. Borde. The claims for this process are interesting and extraordinary. Finding the Classen process unworkable on a commercial scale, the company that controlled those patents for France is reported to have so modified the process as to largely increase the value of the by-products, chiefly the acetic acid and the solid tailings, and can still produce about 20 gallons of alcohol per ton. The raw material is treated in a Classen converter with a solution of sulphurous acid at a pressure of 100 pounds. Neither the time required —a most important item— nor the form of the converter, nor yet the quantity of acid used, are stated in the report. From the profound change effected in the character of the wood, however, the process must be greatly prolonged and the sulphuric acid formed given ample opportunity to attack the cellulose. The digested mass is allowed to partly cool in the digester when it is found to have shrunken about 25 per cent. The sulphurous acid is recovered and the material from the digester passed over to a separator in which the acetic acid is recovered by vaporizing it with steam. The whole mass, without any attempt at separating the sugar, is then neutralized, made into a mash, which is fermented and distilled in the same way as an ordinary grain mash is handled in a whisky distillery.

The tailings from the still are compressed and dried as in the previous process by waste gases from the boilers. This material is claimed to be useful as a stock food, or can he briquetted or mixed with magnesla to form artificial stone of value. In an experiment conducted by the writer I am quoting, be obtained from 3,200 pounds of refuse wood, 211,4, gallons of 94 per cent alcohol, 76 pounds of acetic acid and 1,800 pounds of stock food. The value of this he estimates as follows:

Alcohol at 40 cents per gallon. . . . . . . . . . . . . . . . . . $8.60<BR> Acetic acid at 6 cents per pound. . . . . . . . . . . . . .. 4.56<BR> Stock food at $23 per ton. . . . . . . . . . . . . . . . . . . . .. 17.25<BR> $30.41<BR> Estimated cost of production. . . . . . . . . . . . . . . . .. $7.00<BR> Net profit. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 23.41<BR> $30.41<BR>

If this be a true estimate of the value of the products obtained from a ton and a half of sawdust. it is much more profitable than the process 1 have reported upon. The ethyl alcohol produced according to the above is of secondary importance both commercially and economically to the manufacture from sawdust of a foodstuff for stock of greater value than Indian corn. The description of the process does not convince one that the inherent difficulties of the Classen process have been removed. The exaggerated value placed upon the stock food is obvious. There is no reason, however, why a. prolonged digestion of wood at a high temperature should not greatly increase the yield of acetic acid and might produce a substance from cellulose by the hydrolyzing effect of sulphuric acid which might have a food value, but necessarily a very low one after the extraction of the sugar. It is known that the partial hydrolysis of keratin (horn, hoof, hair, etc.) renders such substances digestible. If the process be carried so far as this, however, it seems very probable that the sulphuric acid formed would destroy much of the sugar and thus lower greatly the yield of alcohol. In the Ewen-Tomlinson process which I have studied, it was found that the more rapidly the contents of the digester could be raised to the required temperature the shorter was the time required to produce the maximum yield of sugar. A gradual elevation of temperature. as occurs in the Classen process, induces secondary reactions and a lower yield of fermentable sugar. This rapid heating of the contents of the converter is only possible by the Ewen-Tomlinson method of introducing live steam into the interior of the mass by the perforated tube in the axis of the converter.

All will watch with interest the development of these two offsprings of the Classen process in America. A plant is being erected to use this French process at Hadlock, Wash., and another is proposed for some place in Ontario.

As to the cost of production of ethyl alcohol by the Ewen-Tomlinson process, a very close estimate has been made, based upon tenders and the experience of the patentees in the Classen plant. Broadly speaking, the cost is about the same as that required to produce alcohol from grain or any other starchy material. Outside the converter itself there is nothing used in the plant which is not quoted on the market and made for other purposes. Without going into details, a plant capable of handling 100 tons of dry sawdust in a ten-hour day, or working continuously, 200 tons per day, including buildings of a simple character and of cheap substantial construction. was estimated at $99. 500. The daily cost of maintenance, including interest, depreciation, labor, and material, allowing 50 cents per ton for the sawdust or other wood waste, would amount to $217, i. e., $217 for 100 tons, or $2.17 for 20 gallons of alcohol, 90 per cent, or a net cost of 10.8 cents per gallon. No allowance is here made for fuel, save the cost of drying the unused portion of the saw dust. This estimate further is made on a plant not smaller than 100 tons.

When one considers the possible value of the by products from a large plant, and the fact that quite 20 per cent of the available sugar was not fermented in the experiments made last June, it would appear that cheap industrial alcohol has at last arrived.* Ethyl alcohol from grain. 94 per cent, averages about 52 cents to the consumer without the government tax, and denatured alcohol from 45 to 60 cents. Alcohol made from refuse wood should not cost the consumer more than 20 to 25 cents.

Quite apart from its economic aspect, the manufacture of fermentable sugar from wood by this process is intensely interesting to the chemist. The process is essentially one of hydrolysis analogous to the conversion of starch to sugar by the amylolytic ferments. The celluloses are, like starch, polysaccharides of unknown constitution. They are generally represented as having the same percentage composition and empirical formulae, and just as we can represent the hydrolysis of starch to maltose and dextrose, so we can show how by the assimilation of water the cellulose can give rise to maltose and dextrose. It is assumed that it is the cellulose element in the wood which gives rise to the sugar.

I was much struck by the regular action of sulphurous acid upon the sawdust. a constant quantity, about 35 to 40 per cent of the wood, only being attacked. We know from the studies of numerous chemists, such as Hugo Muller. Sachs, Cross and Bevan, and others, that wood freed from adventitious constituents such as the tannins, coloring matters, resins, etc., is strikingly uniform in the composition of its fundamental tissues. notwithstanding the great variety in structural complexity, and this uniformity in composition is not confined to species, but is found to embrace all sorts and varieties of woody tissue. The average composition of wood from all sources may be said to be, water, 11 per cent; cellulose, 50 per cent; soluble in water, 3.5 per cent; non»cellulose, 35.5 per cent. Lignum vitae and ebony are exceptions, being very low in cellulose and high in non-cellulose.

In the Classen patents and in one of the Ewen-Tomlinson patents it is the cellulose which is claimed to be converted into fermentable sugars. It seems more than a coincidence that the quantity of material hydrolyzed in the Ewen-Tomlinson process should be so constant and should correspond so closely to the proportion of non-cellulose found in woods. in all processes of hydrolysis the non-cellulose or lignose complex>is the first to break down whether the hydrolysis occurs in an acid or an alkaline medium. There is every evidence that here the lignone complex is broken down. The presence of hydroxy-derivatives of benzene. of pentoses, acetic acid, and furfurol in quantity is obvious in the liquid extract of the treated wood. it seems probable that the lignone complex in woods is attached to a certain proportion of cell cellulose (hemi-cellulose) as well as to the oxy-cellulose and perhaps to the true fiber cellulose.

The material left after treatment consists of cellulose, which is found on being again submitted to steam and sulphur dioxide to yield but a trace of, sugar. True fibrous cellulose (absorbent cotton) in another experiment remained unattacked. Its physical as well as its chemical properties were practically unchanged.

Under the conditions of the process a small quantity of sulphurous acid is employed for a short time only, and very little sulphuric acid is formed. It would seem that the acid acts here as a catalyzer inducing a rapid hydrolysis of the lignone complex and of a proportion of easily attacked cellulose. The oxy-cellulose for the most part and the true cellulose present are not seriously altered chemically. It would seem possible that, authorities to the contrary notwithstanding, the lignone complex is capable of yielding a certain amount of fermentable sugar. Should this, on further study, prove to be the case, it might be possible to treat pulp wood by this process as a preliminary to its conversion into pulp, and then by a second treatment to produce pulp fiber from the unattacked residue.

There is little doubt that in the original Classen process there was, owing to the larger proportion of acid and the prolonged action, a more profound action on the cellulose and the lignone complex, as well as probably a secondary action on the carbohydrates produced.

In a lumber producing country like Canada. any industry that can utilize waste wood and give it commercial value should receive encouragement. If this be the “revolutionary discovery," which the Department’ of Agriculture at Washington has pronounced it to be, it will add much to the wealth of nations. it will not only open up new fields for the use of industrial alcohol, but will liberate for use as food the million bushels of grain now used in the manufacture of ethyl alcohol, 9 per cent of which is used as a luxury in life and regarded by many as a distinct evil in the community.


 * Read before the Society of Chemical Industry, and published in its journal.

+ Tenders have been offered to deliver, two hundred yards away, 200 tons of sawdust. etc., per day at twenty-five cents per ton.

' The Standard Alcohol Company claims to be able to produce this alcohol at a cost of seven cents per gallon in a large plant. Its plant has been described in the SCIENTIFIC AMERICAN

SCIENTIFIC AMERICAN SUPPLEMENT September 14, 1912
This is a excerpt from the article. The first part of the article has the historical information. The rest of the article describes the experiments.

Some Experiments on the Hydrolysis of Sawdust*<BR> Sugar and Alcohol from Wood<BR> By Wallace P. Cohoe<BR>

The effect of acids upon cellulosic materials has engaged the attention of chemists since the time of Bracconet in 1819.

Simonsen was the first to attempt the manufacture of sugar from sawdust on any large scale. He used both sulphuric and hydrochloric acids of from 0.3 to 0.7 per cent strength in quantity under a pressure of seven to eight atmospheres.

In Classen's process fairly dry sawdust was treated with 2}4 to 3 per cent of sulphurous acid, the amount of moisture present usually equalling the weight of dry sawdust. The digester was heated externally, and the excess of sulphurous acid was blown off and recovered. This process has been exploited, but cannot as yet be pronounced a commercial success. Though the yields of this method are very satisfactory, both in quantity and quality, yet the slowness of external heating seriously limits the output of a plant.

Reference should be made to the recent developments which have been made in Sweden in fermenting the sugars produced in the digestion of sulphite pulp. It is apparent that the hydrolysis of sawdust by sulphurous acid and acid sulphites, is making the production of alcohol possible on a commercial scale.

In Ewen and Tomlinson's method, which is being worked commercially in North America, sawdust is hydrolysed by sulphuric acid, the glucose produced being subsequently fermented. In this process conditions of moisture and percentage of acid approximate those of Classen, but the digester is heated internally by means of live steam.

Attracted by the fact that hydrochloric acid seemed to be more active than other acids in decomposing cellulosic materials, I was led to investigate the action of hydrochloric acid upon sawdusts under conditions where the reacting materials should be heated internally by live steam, and where the amount of water present should not exceed by more than 50 per cent the weight of dry sawdust in the digester.

Investigations on a commercial scale of methods not described in this paper are outlined in United States Patent (No. 985,726).

EXPERIMENTAL PART.

....

<TT>*</TT> Reproduced from the Journal of the Society of Chemical Industry.

SCIENTIFIC AMERICAN SUPPLEMENT August 10, 1912
The Production of Ethyl Alcohol from Waste Products'<BR> By Alcan Hirsch<BR>

The first synthesis of ethyl alcohol was made about 1826, by Hennel, utilizing the reaction of ethylene and sulphuric acid to form sulphovinic acid which, upon heating with an additional quantity of sulphuric acid, yields alcohol. Berthelot improved this process by synthesizing ethylene from its elements via acetylene, and by making a more complete conversion of ethylene into sulphovinic acid. The one source of the alcohol is the action of the zymase of yeast upon glucose and other fermentable sugars. The sources of the fermentable sugars may be grouped into two classes:

1. The products of the hydrolysis of starch and allied substances by means of an amylase. 2. Solutions of sugars obtained directly from fruits and plants and from the non-crystallizable by-products of sugar-works—such as molasses.

The most economical source of starch in our country is probably Indian corn, costing about $21 per ton. One ton of corn gives about ninety gallons of 94 per cent alcohol. About two gallons of raw molasses produce one gallon of 94 per cent alcohol, and this raw material costs about 21 cents per gallon of 94 per cent alcohol. The costs of the distillation of the mashes and the rectification and purification of alcohol cannot be entered into here, but the approximate cost of 95 per cent alcohol (190 proof) to the consumer may be taken as about 50 cents per gallon, exclusive of taxation.

Within the last two or three years, two new commercial processes for the production of alcohol have been put in operation on a comparatively large scale. The purpose of this article is to present and discuss briefly from a chemical engineering standpoint these two processes: namely, the production of alcohol from sulphite cellulose waste lyes, and the production of alcohol from sawdust.

I. ALCOHOL PROM SULPHITE LYES.

In the sulphite process for the production of pulp, for every ton of cellulose there are about ten tons of sulphite lyes (T. H. Norton, U. S. Cons. Rep., November, 1911) which contain one-half the weight of the wood originally introduced into the boilers. Among the substances present are: dextrose and other sugars, xylose, acetic acid, tannic acid, nitrogen compounds, methyl alcohol, resins, etc., and calcium lignin-sulfonate, the chief product of the reaction. Most of the sugars in these lyes are fermentable and constitute about 1 per cent of the lyes, the yield of alcohol being from fifteen to sevonteen and one half gallons per ton of cellulose (C. G. Schwalbe, Z. angew. Chem., 23, 1537, 1910).

Recently in Sweden two industrial processes have been developed, that of Ekstrom (P. G. Ekstrom, Eng. Pat. 6714, March 17th, 1910) at Skutskar and that of Wallin at Forss. These processes are practically identical, differing only in the neutralization of the acid. The former uses lime, chalk, etc., and the latter waste causticization sludge. The general scheme is as follows: The lyes are first neutralized in large vats, then cooled in towers and aerated. In a mill producing ten tons of cellulose per twenty-four hours the volume of the lyes to betreated is about nine thousand gallons per day. A yeast nutrient, malt extract or dead yeast is added to the cool, neutral liquid which is transferred to the fermentation vats. After fermentation (which takes three days or more) the yeast is separated and the liquid distilled in a continuous still. The percentage of alcohol is very low and considerably more steam is used in the distillation than is required with mash from molasses which usually contains about 7 per cent alcohol by volume. The alcohol obtained is already denatured as it contains considerable methyl alcohol (from the unfermented lyes), furfurol, aldehydes, and sometimes acetone, but is practically free from terpenes.

The above process with a few minor changes is being worked on a large scale at several places in Sweden. The experimental plant at Skutskar began operations on May 24th, 1909, using waste lyes from a 5,000-ton cellulose plant. In March, 1910, 560 gallons of "normal strength" alcohol were produced per 24 hours. The total for the month was about 13,000 gallons. The process yields about 6 gallons of absolute alcohol for 1,000 gallons lye, and about 14 gallons for every ton of cellulose.

As the alcohol produced from waste lyes is denatured, its chief uses will necessarily be for heating and other industrial purposes. The industrial prospects of this process depend on the cost of production, condition of taxation and capacity of the market. Estimates of the cost of production for a mill producing 340,000 gallons per annum place the cost at about $9.50 per 100 gallons. In Sweden the tax per gallon increases with the output, so that for an annual production of 340,000 gallons, the cost of production including the tax is about $15.50 per 100 gallons. In Germany excise regulations penalize new distilleries so that in addition to the cost of production, sulphite spirit would be subject to a tax of about $17 per 100 gallons. Regarding the capacity of the market, in Sweden during the fiscal year 1908-1909 the total production of alcohol was about 5,800,000 gallons (absolute) and the imports were about 310,000 gallons. The sulphite lye mill at Larkudden is reported as having produced spirit during the year 1910 at the rate of 157,000 gallons per annum, and the annual rate of production at the present time is estimated at 250,000-400,000 gallons. The pulp mills of Sweden can produce 6,500,000 gallons of absolute alcohol per annum. It must be remembered that the present method of production from grain is always intimately connected with the agricultural industries of the country, and therefore will not be easily displaced. Also, while under special conditions (especially low taxation) the sulphite process can be worked at a profit, yet it does not solve the problem of the disposal of the waste lyes, as only about 1 per cent of the total weight of lyes is converted into alcohol. In fact, on account of the presence of dead yeast, etc., the problem of the disposal of the lyes may be aggravated by the use of this process.

II. ALCOHOL FROM SAWDUST.

The cost of raw material is always of great importance in any industry. While Indian corn costs about $21 per ton, sawdust in the vicinity of a large mill where it is a by-product can be bought at a cost of 30 to 50 cents a ton including handling and transportation (short distances). One ton of sawdust calculated to the dry basis can yield 20 gallons of 94 per cent alcohol, which makes the cost of this raw material 2l/% cents per gallon 94 per cent alcohol, as against 24 cents for Indian corn.

For nearly one hundred years it has been known to chemists that fermentable sugars can be produced from sawdust. The reaction is usually spoken of as being very simple, all that is necessary being to add a molecule of water to the cellulose. This hydrolysis is probably as complex as it is baffling. The unknown composition of those polysaccharides which we call cellulose and the very different results obtained on hydrolysis under slightly different conditions of catalyzer, temperature and pressure indicate that somewhat intricate reactions occur, the complete chemistry of which is not known at the present time. A very largo number of patents have been granted on this reaction, the main differences being in method of manipulation and the catalyzing acid used. Sulphuric acid has been used in many cases, but the subsequent removal of this acid has proved a serious stumbling-block. No process that was capable of commercial application had been devised until the year 1900 when Dr. Alexander Classen was granted his first patent. The more import ant English patents granted him are: No. 258, January 4th, 1900; No. 4,199, February 27th, 1901; No. 12,588, June 20th, 1901. "Process claimed consists in boiling cellulose in a closed vessel at a temperature of 120 to 145 deg. Cent, with a solution containing sulphurous and sulphuric acids or sulphurous and hydrochloric acids. A solution of 2 per cent or more of sulphurous acid and 0.2 per cent sulphuric acid is mentioned. The sulphuric acid may be conveniently formed in the boiler by admission of air or other suitable oxidizing agent. In this way concentrations of 10 per cent sugar may be obtained, 80 to 90 per cent of which is fermentable. Conversion is complete in 15 minutes."

An experimental plant using this process was erected at Aachen and a similar plant on a larger scale was built at Highland Park near Chicago. The results were satisfactory so that it was decided to build a commercial scale plant at Hattiesburg, Miss. The capacity of the conversion cylinder was two tons. After the conversion the acid was neutralized, cleared by subsidence, pumped into large vats and fermented by yeast and then distilled. From a commercial viewpoint this plant was a complete failure. From a chemical engineering standpoint it is an excellent example of a process which fell just short of success. The reasons given for the failure are: 1. Length of time required for conversion: \Yi to 2 tons requiring 4 to 6 hours. 2. Prolonged action produces gums and caramels and makes extraction of the sugar tedious and expensive. 3. Large quantity of acid required. 4. Lining difficulties, especially with lead linings.

Two chemical engineers, Ewen and Tomlinson, studied and undertook to improve this process. Their patent U. S. 938,308, 1909, describes their process. The converter used by Classen was about 30 feet in length and had a diameter of 3 feet, whereas in the Ewen and Tomlinson process the digester is much shorter, usually being about 12 feet in length and 8 feet in diameter. The latter line their converter with fire-brick instead of using the troublesome lead lining. The operation seems to be fairly simple. Sulphur dixoide gas to the extent of 1 per cent of the weight of the wood is introduced into the cylinder and live steam is turned on until a pressure of 100 pounds is obtained. The steam is then turned off and the cylinder slowly revolved for 40 to 45 minutes, the temperature and pressure being kept constant. The total time of conversion is about 1 hour as against 4 to 6 hours in the old process. In operating this process it is important to raise the temperature as quickly as possible to the "critical point" which is defined as "that temperature above which the production of unfermentable substances and the destruction of the sugars become excessive and lie between 135 and 163 deg. Cent." After extraction, the converted lyes have a total acidity of 0.64 per cent (calculated to HiSOj) containing sulphuric and acetic acids, a small amount of sulphurous acid and aromatic compounds of the type of pyrogallol. These liquors contain about 5 1/2 per cent of reducible sugars calculated to dextrose. Polyphenols, tannin and furfurol are usually present in small amounts. These liquors are fermented and distilled in the usual manner, some care being required in the fermentation to have present a proper food for the yeast. The distilled alcohol obtained is potable, free from the odor and taste of wood, and from methyl alcohol and fusel oils, but contains traces of furfurol and aldehydes. One and one half tons of dry wood give about 6 1/2 gallons of 94 per cent alcohol. From figures obtainable it appears that the efficiency of the process is from 75 to 80 per cent of the theoretical yield of alcohol.

The Dupont Powder Company is operating a plant at Georgetown, South Carolina, for the production of alcohol from waste woods. This plant is licensed under the Ewen and Tomlinson patents, and while no figures were obtainable, it is stated that experiments so far indicate the ultimate success of the process.

W. P. Cohoe is the inventor of a process for making fermentable glucose-like substances from cellulose and ligneous materials (U. S. Patents 985,725, 985,723, 1911). The conversion is done in two stages: first, steam is used producing acetic acid which is collected, and then steam and HC1 vapors are introduced into the converter. The raw material used is generally sawdust.

The cost of production of alcohol by the sawdust process (Ruttan, J. Soc. Chem. Ind., 1909, p. 1290) is said to be about equal to that of grain, although there is such an enormous difference between the cost of the raw materials. One company, however, claims to be able to manufacture alcohol by the sawdust process at a cost of 7 cents per gallon.

Without going into the details of the chemistry involved, it is striking that, although the patents claim a conversion of cellulose into sugar, the so-called true fibrous cellulose, absorbent cotton, does not yield to this treatment. Also the material left after treatment contains cellulose which upon re-treatment yields but traces of fermentable sugar. Although authorities differ, it is claimed by some that the acid acts as a catalyzer hydrolyzing the lignone complex and a proportion of the "easily attacked cellulose." The oxycellulose and the "true cellulose" are said not to be seriously altered chemically.

It would seem that there is a possibility that a process might be evolved where the alcohol conversion of the wood pulp might be made first, and then the residue subsequently utilized for the production of paper pulp.

<TT>*</TT> Reproduced from the Journal of Industrial and Engineering Chemistry.

SCIENTIFIC AMERICAN SUPPLEMENT No. 2263 May 17, 1919
The Motor Fuel Problem*<BR>

EXPERTS in different industrial branches Would, On inquiry, probably draw up different lists of key industries. None of them, however, would omit to class the industry of internal combustion motors among the most important key industries, and this not only because these vehicles are still wanted in the Army. The war has so thoroughly changed all industrial foundations—quite apart from political and national considerations—that it will for some time to come be difficult to dismiss it from our minds when estimating the future. What was necessary, possible and probable during the war, may become undesirable and impossible in normal times. Some of the special uses of motors, uses which have rendered their rapid perfection possible, may vanish. But the motor will conquer other fields in which it had before the War already obtained a firmer footing in other countries than Over here. Authoritative Statistics are not available at present. To characterize, however, the importance of the industry, Mr. W. R. Ormandy, D.Sc., when discoursing on the Motor Fuel Problem before the Institution of Petroleum Technologists recently, stated that he estimated the wages paid annually in this country for the manufacture of motor vehicles at more than 10,000,000l. That estimate entirely disregards accessory industries connected with light alloys, Springs, rubber, tires, leather, &c., some of which may almost be said to stand and fall with the motor as matters are now. The United States are credited with 5,500,000 motor vehicles, half of which serve for farming, forestry, mining, stock raising, fisheries, &c. Motor transport and agricultural developments are inseparably linked. In the future aeroplanes will need such motor fuel. A Handley-Page machine alone consumes as much as 40 motor cars per hour, Dr. Ormandy believes, and even without the war the country would have wanted 200,000,000 gallons of motor spirit per annum by this time. Where is the fuel to come from?

America produces some two-thirds of the world's petrol from natural oil; but it has long felt the pinch, and though new petroleum fields are opened, old ones dry up, and an actual world shortage will have to be met sooner or later. What other fuels can be utilized in internal combustion engines? Dr. Ormandy distinguished them as solid, gaseous, liquid. Solid coal can be gasified in the producer, but bituminous coal is hardly suitable for such purposes. The last word has not been said regarding steam-driven motors, how ever; the Clarkson motor omnibus has so far been run On paraffin, but Mr. Clarkson has, according to Mr. Ormandy, obtained promising results with coke-fired boilers. As regards charcoal, the woody lignites of Ireland may give a suitable fuel for producers. But though solid fuels may be adapted to serve as indirect fuel for stationary engines and heavy portable motors, they cannot play an important part. That gaseous fuel, compressed town gas, can be burnt in motors, has been shown ; 250 cub. ft. of gas are considered equivalent to a gallon of petrol; the introduction of suitable containers would render another auxiliary source available; but it would not do more.

The more important liquid fuels are petrols, paraffin oils for marine engines, &c., and fuel oils for Diesel or semi-Diesel engines. Substitutes for petrol are gained by coal distillation. By-product ovens yield from 1% gallons to 3% gallons of liquid fuel per ton of coal carbonized. From the gas of gas works similarly 1 gallon or 2 gallons of benzol and toluol are obtained, and post-war conditions, Mr. Ormandy Suggested, might yield some 50,000,000 gallons per annum. If central electric power stations should take the expected development in combination with producer gas plants, however, that figure would be smaller. Shale oils help also, and the sulphurous shale deposits from Norfolk down to Dorset might be utilized; but that again would be a minor factor. The next available source, alcohol, could certainly be produced in almost unlimited quantities; but the heat of combustion of alcohol was relatively low, alcohol was not readily inflammable, and the advocates of alcohol-fuel had prejudiced their own cause. In any case little had been done by the public, the motor users, to whom motor manufacturers left that problem, and the Government had been guided by the experts of the Excise Department Alcohol could, and was, produced in the first instance from sugar molasses by fermentation, and there was no reason why sugar beet crops should not thrive here. If grain-raising were to be pushed, in fact, roots would have to be planted in rotation, and sugar-beet root might profitably replace turnips and mangolds; Dr. Ormandy seemed to forget that sugar-beet roots require heavy manuring. Sugar-alcohol, however, cannot directly supply the Empire's motor fuel, even if local industries, like the sugar manufacture from the Indian mowrah-tree flower, were fostered.

But there are indirect sources of sugar. By digestion with alkalis or acids both starch and cellulose are converted into fermentable sugars. The English glucose is mostly starch-sugar, and quite an important article as such. The most common source of starch is the potato. In Germany, Dr. Ormandy rightly pointed out, alcohol is not produced from potatoes because they form the cheapest raw material available, but because their use favors home agriculture. Hundreds of square miles of sandy soil, notably in the eastern part of Prussia, sustain an agricultural population, which is occupied in the fields in summer, is busy in the distilleries in the winter, and obtains a valuable cattle food in the distillery residue (Schlempe). The special potatoes for the distillery fetch about 228. per ton in Germany; that money, however, would not alone keep the people, if it were not for the work and other profits drawn from an agriculturally poor soil. The Prussian Government has wisely encouraged potato farms and local distilleries which are the joint property of small peasants or owned by the great landlords. The question, however, is not really capable of such brief summation as Dr. Ormandy attempted. He did not overstate his case, however, and he warned his hearers against the optimistic estimate which Mr. R. W. Tweedy had given in a pamphlet on industrial alcohol. The alcohol yield of the best special potatoes does not exceed 20 gallons or 25 gallons of 95 per cent. alcohol per ton of potatoes, and Ireland could not produce 150,000,000 gallons of alcohol from 2,500,000 tons of potatoes, certainly not if the potatoes were to be sold at 31. 108. per ton to the distillery. For warmer climates, in Australia and Africa, maize yielding 75 gallons of alcohol is a much more promising material, of course.

Successful experiments on the conversion of cellulose into sugar by the Classen process have recently been made in the United States, on a large Scale, Dr. Ormandy mentioned; but he did not give particulars, except that he spoke of a yield of 30 gallons or 40 gallons of commercial alcohol per ton of wood. How these figures compare with the 10 per cent. of 95 per cent. alcohol which the Ewen-Tomlinson process is said to yield, we do not know. The difficulties lie mainly in the construction of suitable vessels not attacked by hot acids under pressure. The sulphite wood-pulp residue treatment seems, however, really to have risen from the experimental stage, if Sweden has works producing 4,000,000 gallons of alcohol per annum in operation, and works for 3,000,000 gallons under construction; Norway is credited by Dr. Ormandy with works for 4,000,000 gallons, the strength of the alcohol not being stated. Sulphite wood pulp is the residue from paper-making with calcium or magnesium sulphite (instead of the more expensive caustic soda). The logs are sliced at right angles to the fibre and boiled for 5 hours or so at 2 atmospheres pressure in vessels lined with lead; the sulphite is prepared in Glover towers or in Vats. The sulphite liquor has so far practically been a waste product; there are difficulties about neutralization to start with, and it would be interesting to know how alcohol is obtained from the liquor, though it generally contains some sugar. There is finally the synthetic production of alcohol, from calcium carbide via acetylene. Such processes are certainly worked in Germany and by the Lonza Company in Switzerland, as we noted some time ago; with what results is not yet known.

With the question of the suitability of alcohol as motor fuel we have dealt On other occasions. Thousands of alcohol motors, chiefly stationary for agricultural purposes, engines working with long stroke and high compression and fitted with pre-heaters for starting, were working on the Continent before the war. The higher thermal efficiency of these alcohol motors balances the lower heat value of the fuel, and the much-dreaded corrosion of the cylinders can be averted, as Continental experience and the experiments carried out by the Auto-car prove. That alcohol can also be used as fuel mixed with benzol, in the ratio of 2:1, e.g., without calling for more alteration of the engine than required for pre-heating the air supply and slightly enlarging the jet, is likewise established; motors run more smoothly on such mixtures than on petrol according to Dr. Ormandy. There is, of course, need for further research, as to viscosity, vapour tension, the admissible percentage of water, and the best proportions of mixtures of benzol, alcohol and water, and also alcohol-benzol-ether mixtures. Lubrication problems may also arise. The use of paraffin oil mixed with petroleum caused trouble in the bearings, and Dr. Ormandy found out in experimenting together with Mr. Lester that, when petrol is used, a certain amount of this fuel gets into the crank-case oil and sets up an equilibrium depending upon the temperature of the oil, the amount of ventilation and other factors. Moreover, with paraffin, which has a lower vapor pressure, larger quantities are washed out and retained by the oil spray in the crank-case, so that the viscosity of the lubricating oil is diminished.

The main questions are, however, how the supply and the distribution of an alcohol-benzol mixture, in the ratio 2:1, can be secured and maintained. These are largely financial questions, which Dr. Ormandy argues on the following lines. The United States are supposed to have built 1,700,000 motor vehicles (not including motor ploughs, boats, aeroplanes, petrol driven lighting and pumping sets) during the past twelve months. At the rate of 400 gallons annually these motors would alone consume some 700,000,000 gallons or 2,000,000 tons of petrol; supposing crude petroleum to yield 20 per cent. of petrol, an additional 10,000,000 tons of crude oil would be required to keep the American cars of one year on the road. The world's production of petroleum probably does not exceed 50,000,000 tons per year. The present production of benzol for motors in this country may come up to 50,000,000 gallons per annum; if 100,000,000 gallons of alcohol were also available, the present demand could be met. To double the benzol output of petrol, as we shall see, necessitates that the output of the gas works and the iron and steel trade should be doubled, and the enormous capital involved in these expansions cannot be got into operation as rapidly as the fuel demand is increasing. There is hence no alternative in sight except alcohol. This demand for alcohol is no new fancy, of course. The report of the Imperial Motor Transport Conference of 1913 may be summed up in the words “Develop alcohol fuel,” and Dr. Ormandy himself had advocated alcohol in the Automobile Club twenty years ago when petrol was 18 per gallon. An Inter-Departmental Government Committee, of which Sir Boverton Redwood is chairman, is dealing with fuel-alcohol.

We pass to the distribution problem and the gas and iron works. The production of benzol depends upon gas works and coke-oven works. The gas works will grow, and hence be able to produce more benzol; but they will also have to utilize low-grade coal, and to face many new problems Dr. Ormandy, we might interpose, seems to presume that the gas companies are willing to go on with stripping the gas; some gas engineers certainly wish to be relieved of this obligation. Coke ovens, the other source of benzol, can only grow together with iron and steel works, and whether they will put down benzol-recovery plant will depend upon the market value of the benzol. To control the market the petroleum companies will endeavor to obtain possession of the benzol supply. They can rightly claim that they are able to mix the benzol with the petrol and that they possess the organization necessary for distributing the product. The benzol producers, likewise organized, might dispose of their whole production to the petroleum firms at an agreed price, or on a sliding scale, to be relieved of the distribution worry; but they cannot expect to control the motor fuel market if they supply only part of the total demand. The petroleum companies hold the field apart from the benzol; they are corporate bodies existing for the purpose of making profits. They can also retard the progress of alcohol. Thus the fuel users, the public, will be shorn, unless the Government step in, or the users combine with the motor industry to secure the benzol supply of the Country as a national asset. They will combine, Dr. Ormandy thinks, if they recognize the situation.

<TT>*</TT> From Engineering.

SCIENTIFIC AMERICAN MONTHLY June, 1920
Three New Sources of Fuel Alcohol*<BR> Production of Alcohol from Molasses, Wood Waste and Acetylene<BR>

GERMANY which, prior to the war manufactured alcohol only from potatoes and grains, when compelled by the Allied blockade to conserve its food supplies, resorted to different methods of alcohol production, some of which were formerly commercially Impractical and others entirely unknown in that country. These include the following processes :<BR> a. Process based on the use of molasses.<BR> b. Process utilizing the sulphite liquor of plants for the purification of wood pulp.<BR> c. Process consisting in saccharifying wood and fermenting the sugar thus produced (grain alcohol from wood).<BR> d. Process of generating alcohol by the hydrogenation of acetic aldehyde, which in turn is obtained by fixing the element of water on acetylene (carbide alcohol).<BR>

The German government assumed full charge of alcohol production, and it was feared in the industry that this step, which was taken as a war measure, would not be rescinded, but would result In an alcohol monopoly in the future.

This project of an alcohol monopoly was adopted on Its third reading by the Reichstag, on July 13, 1918, by the Bundesrath on July 19, and finally promulgated as a law on the 26th of the same month.

In the text of this bill is found some very Interesting in formation on the new processes (b, c and d) referred to in the foregoing. There is no need to refer here to the fiscal character of this law, but the technical appendices will be of interest to our readers, and a translation is here given. Aside from the technical Information contained therein, these appendices furnish general indications regarding the economic values attributed to the different methods at the time.

In cellulose plants, the wood pulp is boiled in an aqueous solution of bisulphite of calcium, In order to purify the cellulose contained in the wood, by the elimination of materials with which it is Impregnated. Up to quite recently, this bisulphite solution, after it had once served its purpose, was not recovered, but was drained off and often caused great damage.

During the early part of 1900 It was discovered that the waste liquors of German cellulose factories contained a little more than one per cent of sugar, and it was found that from 1,000 cu. ft. of this waste liquor it was possible to recover from 42.5 to 50 gal. of alcohol. These results were verified in 1915 by renewed experiments. The discovery, however, was never put to practical use in Germany, for the reason that the manufacture of alcohol from sulphite waste liquors — In view of the fiscal regulations concerning alcohol then in force — would have yielded no profit. Moreover, the often expressed belief that by the treatment of the sulphite waste liquors for the production of alcohol (that Is to say, by the elimination of the sugar content), the delicate question of waste liquor disposal would be solved, was not a sufficient incentive. In Sweden, on the other hand, the manufacture of alcohol from waste liquors was successfully taken up during the year 1909, and in that country there are now numerous plants for the production of alcohol from sulphites.

Under the compelling influences of the war the manufacture of alcohol from sulphite waste liquors was taken up anew in Germany, and the experience gained in Sweden was turned to good account.

The process for recovering alcohol from sulphite liquor comprises three operations, as follows: (1) The preparation of the waste liquor for fermentation; (2) the fermentation of the sulphitic must, and (3) the distillation of the fermented sulphite solution.

Sulphite waste liquors contain, in addition to sulphurous acid, which interferes with the fermenting action of the yeast, acetic acid and formic acid. These acids are eliminated partly by blowing air through the waste liquors, after they have been raised to a temperature of 185-195 deg. fahr., partly by the addition of carbonate of lime and of a little slacked lime. The neutralization must be carried to a point necessitated by the subsequent fermentation. This Is accomplished in concrete tanks in which the waste liquor is allowed to remain for some hours In order that It may be come clarified. This is followed by another clarification of the liquor from which the mud has been separated, which is accomplished in a reservoir which serves for filling the fermentation vats. The waste liquor is then transferred to a concentration tank cooled by air, in which at the same time it is cooled, saturated with air and concentrated to a certain degree.

Fermentation takes place in tanks of 3,500 cu. ft. capacity, with the aid of a very active yeast, which has been slowly accustomed to the conditions which the fermentation of the waste liquor presents, and which is continually transferred from a tank In which fermentation has been completed, into a fresh tank. The sulphate waste liquor contains insufficient quantities of nutriment for the yeast, and for this reason there Is added either ammonium sulphate, or super-phosphate, or, on the other hand, a yeast extract which is prepared in distilleries with waste liquor containing an excess of yeast. The fermentation takes place at 84-85 deg. fahr., and on the average requires 72 hours, producing from 66-72 gal. of alcohol from 1,000 cu. ft. of waste liquor.

The alcohol contained in the fermented waste liquor is eliminated in large distilling apparatuses, in which, on account of the small alcohol must content (0.9 to 0.95 per cent), and on account of the large quantity of liquid to be treated, the application of heat is especially advantageous. The must contains volatile, organic adds, and filters of sodium carbonate must be introduced during the distillation. The distilling apparatus may also receive a charge of a solution of sodium carbonate.

In some plants, the unrectifled alcohol obtained from bisulphitic waste liquors still contains a small amount of sulphuric acid. The only thing to distinguish It from unrectified alcohol obtained from potatoes is the small content of methyl alcohol and of aldehyde. Small quantities of fusel oil are also often found in it. The crude alcohol Is materially improved by the use of distilling apparatus working on the principle of separating the head, In such a way as to obtain, by the separation of the heads (representing 10 per cent of the total) a sulphite alcohol susceptible of being denatured and the heads purified.

The purification of sulphite alcohol does not present any special difficulty. It should be pointed out, however, that rectified sulphite alcohol still contains a little wood alcohol which can be separated from it only with difficulty. Sulphite alcohol may be employed for all purposes for which potato alcohol is suitable.

If we assume a yield of 10.7 gal. of alcohol per ton of cellulose (which corresponds to 0.9 per cent of alcohol in the fermented liquor), the German sulphite distilleries with the plant Installed by them during the war, in one year can furnish 116,000 hectoliters (3,000,000 gal.) of alcohol (corresponding to 1,044,000 metric quintals, or nearly 100,000 tons of potatoes). The total production of the cellulose works working the sulphite process being approximately 600,000 tons per year, in peace-time, by the treatment of all the waste liquors for the production of alcohol, it would be possible to obtain annually 6,400,000 gal. of alcohql (representing a consumption of 240,000 tons of potatoes). Whether the cellulose factories will extend their alcohol production will depend upon what progress is made with other methods of utilizing waste liquors. The small cellulose works, which during the war could work part of their waste liquors for the purpose of producing glues, did not consider it of sufficient importance to erect plants for the production of alcohol.

COST OF PRODUCTION.

The cost of producing alcohol from sulphite Is still undetermined. A diminution of the cost will not be possible until after the fruition of efforts looking towards the concentration of the vinasse derived from the emptying of the sulphite must, and toward the production of methyl alcohol, acetone, acetic acid, and cellulose wax by the dry distillation of this vinasse.

From the remotest antiquity, alcohol has been obtained from the saccharine juices of plants, and from vegetable material containing starch. Experiments with the object of preparing alcohol from cellulose—the carbo-hydrate of the greatest importance next to sugar and starch—were attempted only at a relatively late date. In 1S19 it was found possible, by treating cellulose by means of concentrated sulphuric acid, to obtain a fermentable sugar, dextrose. The production of alcohol from the cellulose contained in wood seemed at first an insoluble problem, in spite of numerous researches. Not only does the need of large quantities of sulphuric acid for the transformation of the cellulose Into sugar occasion heavy expense, but it also involves great technical difficulties, which are due to the fact that it is necessary to separate the acid from the dilute saccharine solution.

Since 1890, chemists have paid renewed attention to the problem of obtaining alcohol from substances containing cellulose, as is evidenced by the numerous patents issued on the subject during that period. The latter generally relate to the transformation of cellulose, tinder the Influence of a dilute mineral acid, and the majority effect the process in close vessels under pressure. Attempts have been made to saccharize the cellulose contained in peat, either by heating it for a long period In contact with an acid at atmospheric pressure, or by heating it for a short time in contact with an acid under high pressure. The saccharine solution obtained by filtration must lie treated with chalk in order to diminish the acidity, and then be submitted to fermentation. For the saccharization of wood and of wood waste, numerous processes have been evolved, which utilize either sulphuric acid, sulphurous acid, anhydrous sulphite or a mixture of these, with the use of steam under pressure. In all of these processes, the sugar derived from the wood should be recovered by drainage. The aqueous saccharine solution should, after neutralization of the acid, be prepared for fermentation. Undoubtedly, this process permits of a yield of 14 to 28 gal. of alcohol per ton of wood in the dry state, starting with wood waste, which up to now was burned as of no value. Nevertheless, in Germany, alcohol derived from wood has not been able to compete with alcohol from potatoes, on account of the excise tax imposed. It is for this reason that none of the attempts in Germany to manufacture alcohol from wood have passed beyond the laboratory stage. On the contrary, in France, England and the United States the manufacture of alcohol from wood has entered the domain of practice. In one plant in the United States, which is said to have an annual output of 500,000 gal., the yield varies from 15.4 to 22.8 gal. of alcohol per ton of dry material.

In Germany a beginning was made in the spring of 1916 in the manufacture of alcohol from wood, with the object of conserving the potato and molasses supply. The Classen process on the one hand, and the process of Windesheim-ten-Doornkaat, on the other, proved themselves best adapted for practical application. By the Classen process the saw dust is heated for 40 min. in rotary caldrons, with sulphurous acid, under a steam pressure of 7 atmospheres (313 deg. fahr. ). The steam is then allowed to expand as rapidly as possible, and the saccharized wood must is emptied out into diffusers. The saccharine solution obtained by diffusion is neutralized up to the necessary point in tanks containing an agitator, an addition of table salt is made, and the mass is allowed to ferment In fermenting tanks with pressed yeast, or beer yeast. The alcohol formed is separated in the usual distilling apparatus. With the Classen process one may count on a yield of at least 14.5 gal. of alcohol per ton of dry material. The process has been improved, so that the yield already has been increased to 20 and 25 gal., and it undoubtedly will be still further increased.

By the Wlndeshelm-ten-Doornkaat process, sawdust is heated with diluted hydrochloric acid in the presence of catalizers (metallic salts), in rotary caldrons, under a pressure of 7 to 8 atmospheres (330-340 deg. fahr.) for 20 to 30 min. The final treatment of the saccharized sawdust is the same as that already described. This process, which is probably subject to Improvement, yields a minimum of 7.2 gal. of alcohol per 1,000 lb. of wood In the dry state.

The alcohol production plants under construction will work according to these two processes. The choice between the two will depend upon the kind of acid most available, and upon the alcohol yield which will be obtained. Germany produces from 500,000 to 1,000,000 tons of sawdust, susceptible of being treated for the manufacture of alcohol. The alcohol factories possess a total of 51 caldrons capable of handling one ton of dry material each. By working day and night, each caldron can handle 10 batches of material daily, or—figuring on 350 working days a year—3,500 batches yearly. That is to say, working to full capacity, it will be possible to treat 178,500 tons of wood annually on the dry basis, or 238,000 tons of sawdust. If one figures on a yield of 14.4 gal. of alcohol per ton of dry material, a total production of 2,570,000 gal. of alcohol per year is arrived at, which is equivalent to the yield from 106,000 tons of potatoes. If the yield can be raised to 24 gal. of alcohol per ton of dry wood, as is to be expected, the production of alcohol will amount to 4,190,000 gal. (corresponding to 176,000 tons of potatoes).

It is still impossible to give any data regarding the cost of producing alcohol from wood. It is certain, however, that it is much higher than that of alcohol from sulphite. The production of alcohol from wood can Become commercially practical only if the wood acted upon, when deprived of its sugar, can be utilized as feed, or rather if it should prove possible to obtain from it acetone, wood alcohol and other products of dry distillation. The necessary research work has not yet been carried out, and at present the only use that can be made of the heat value of the residue of the saccharized wood, is to use it as fuel under the boilers in the alcohol plants.

The unrectified alcohol obtained from wood contains as impurities small quantities of aldehyde, wood alcohol, "furfurol" and fusel oil. The rectification of the alcohol, how ever, presents absolutely no difficulties. Inasmuch as the raw alcohol made from wood, on account of its low alcohol content, cannot be denatured, and therefore cannot be employed for industrial uses, purification readily yields an alcohol which is sufficient for the requirements of powder manufacture. It is still necessary to determine experimentally whether the recovery and commercial utilization of the by products, such as furfurol, will not permit of reducing the cost of producing alcohol from wood.

MANUFACTURE OF ALCOHOL FROM CALCIUM CARBIDE.

When lime and coke are heated to the temperature of the electric furnace, about 5.000 deg. F., a new chemical compound is obtained—calcium carbide. Of all the numerous carbides known, the carbide of calcium is industrially of by far the greatest importance, and for this reason it is generally called simply carbide. It is decomposed by water, forming acetylene, with a residue of lime. If acetylene is introduced into a heated, diluted acid, in the presence of a mercury compound, aldehyde (acetaldehyde) is formed, the components of water being fixed upon the carbide. Aldehyde is a very volatile combustible liquid, of penetrating odor, which combines with hydrogen in the presence of certain metallic catalizers. such as nickel, producing ethyl alcohol (grain alcohol).

As the acid used and the mercury compounds or other metallic catalizers are not modified in the process, or In any case are capable of being returned to their initial state with only small loss, and as the hydrogen may be produced with coke and water, this method of manufacturing alcohol requires only coal, limestone and a rather small amount of heat.

In the manufacture of alcohol from carbide, the following expenses are incurred : 1 —Manufacture of carbide ; for 1,000 gal. of alcohol it is well, in the present state of the art, to count on approximately 6.5 tons of carbide, for the production of which 24,000 kilowatt hrs., S tons of coal and 12 tons of limestone are necessary. If cheap power is obtainable in the neighborhood, as, for instance, water power, or power obtained from cheap fuels, such as lignite and peat, the cost per kilowatt-hour may be as low as 2 pfennigs; in that case, the power cost for 1,000 gal. of carbide may be set down at 240 marks. The cost of the raw material, charcoal and limestone, is approximately 60 marks; the cost price of carbide previous to the war in Germany was 112 to 115 marks per ton. Experience indicates that these figures represent the lower limit, and this statement is corroborated by the figures previously given. As far as can be judged at present, small plants, or those not favorably situated, could not produce at this figure. What the price of carbide may be after the war can only be conjectured. It should be pointed out, however, that the cost of packing for the retail trade, which must he of such a character as to prevent all moisture from reaching the carbide, which cost is not appreciable, need not be considered here, and that the overhead expenses connected with the manufacture of carbide at wholesale need not play a very important part. Moreover, the amount of 2 pfennigs per kw. hr. does not seem to be the minimum at which power can be delivered in Germany.

2—The manufacture of acetylene from carbide does not involve any special expenses for other raw materials, for the decomposition of carbide is effected by means of water, and the purification of the gas is effected by different purifying masses of which some are cheap in themselves, while others are capable of being regenerated, among these latter figuring compounds of copper, chrome and lead, as well as of chlorine and lime. The yield to be expected is 80 gal., equivalent to 0.35 11). of acetylene per pound of carbide of good quality.

3—The following operation, that is to say, the transformation of acetylene into aldehyde, does not involve the consumption of any important amount of raw material, but does Involve the consumption of a large amount of energy. Up to the present, it involves only slight losses. The yield, according to information furnished by the plants (of which none has been in operation for any great length of time) is at most 90 per cent.

4—A most important item in the final operation, the production of alcohol, is the consumption of hydrogen. In order to obtain 1,000 gal. of alcohol, it has been calculated that it is necessary to consume at least 53,000 cu. ft. of hydrogen, which can be obtained at about 2.25 marks per 1,000 cu. ft., this low price being made possible by the low cost of the raw materials, in spite of the expensive installations necessitated for production and purification.

Assuming that all conditions are favorable, that is to say, that the location of the plant is wisely chosen, and that operations are conducted on a sufficiently large scale, one may count on a cost price of 900 marks per 1,000 gal. of alcohol, equivalent to 90 pfennigs per gal., tills including the cost of raw materials. To this must be added some thing for depreciation of plant, salaries, etc., items which are rather difficult to estimate in advance. The purification of the alcohol obtained should not present any greater difficulties than the purification of alcohol obtained by fermentation. As a result of the method of preparation, it does not contain any secondary product of fermentation known under the name of fusel oil : on the other hand, it may contain some sulphuric, phosphoric and arsenic combinations and certainly there will be aldehyde and substances derived therefrom. The best samples so far presented to the government represent a fine industrial alcohol which can be used in most industries.

PRICE CALCULATION.

The preceding price calculations are confined to a certain extent by the conditions of a contract under which a Lonza (Switzerland) concern has engaged to furnish alcohol obtained from carbide to the Swiss government. The price of the rectified alcohol, according to the contract, is to be 1.330 marks per 1,000 gal., the Federal administration taking delivery at the plant in its own tank cars. From a certain point of view, the operating conditions of the plant at Lonza should be better than could generally be obtained in Germany. Undoubtedly this plant gets its power at less than 2 pfennigs per kw. hr. • Near the great waterfalls in Norway, there are large plants which obtain power at approximately 0.5 pfennig per kw. hr. On the other hand, the contract was closed on the basis of high cost of coal (36 marks per ton). The cost price of the Lonza plant (which is a private enterprise) may be estimated at a little more than 110 marks per 100 gal. of alcohol.

It should not be lost sight of that such calculations are subject to numerous causes of error, which are difficult to estimate. If, for instance, the cost of the kw. hr. becomes greater than that previously given, as may easily happen in certain parts of Germany, if the yield of aldehyde or alcohol is a few per cent less than that assumed, or if the renewal of the carbide furnaces occasions greater expense than that provided for, and, finally, if the royalty to be paid on the patent is added, the cost price of alcohol from carbide may come somewhat higher than that arrived at above. A private corporation, which has carried on experiments on a small scale, has reached the conclusion that alcohol derived from carbide cannot easily compete with alcohol of fermentation, even if taxation should be the same.

The process outlined above is so far the only one which has been applied on a large scale. However, it is not the only one theoretically possible. One may also conceive of a process in which no aldehyde is produced, but only ethylene, by the addition of hydrogen to the acetylene. It is an easy matter to pass from ethylene to ethyl alcohol, by a process which has been known for a long time. This has recently been more closely investigated, but it is not yet possible to give any information regarding its success.

Plants already in existence in Germany for the manufacture of carbide and those whose construction has been decided upon, will furnish annually from 400,000 to 450,000 tons of carbide, when operating to full capacity. After deducting the quantities of carbide necessary for lighting, for metallurgical operations, etc., there remain nearly 400,000 tons for fertilizer or for alcohol, and this would produce 66,000,000 gal. of alcohol.

It remains to be investigated what influence the calcium cyanamide obtained from carbide may have on the production of potatoes, and thus on the production of alcohol.

One pound of carbide when heated with nitrogen furnishes 1.25 pounds of calcium cyanamide, containing approximately 20 per cent of nitrogen, and considering that it is customary to count on a gain in yield of 100 pounds of potatoes per pound of fixed nitrogen in the fertilizer, the use of one pound of carbide for the manufacture of nitrogenous fertilizers would result in a gain in production up to 25 pounds of potatoes, equivalent to 0.133 gal. of alcohol; that Is to say, more than four times the amount of alcohol which may be obtained directly by chemical process.

On the other hand, if one considers that calcium cyanamide is now the lowest priced fertilizer, and that the growing of potatoes usually has a very favorable effect upon the following other crops, the direct manufacture of alcohol from carbide cannot be considered seriously until the agricultural demands for nitrogenous fertilizers in Germany have been satisfied in some other way, and filled at an adequate price. On the other hand, it is possible that there will not be a demand for a long time for all of the fertilizer that can be produced by the German plants utilizing carbide. Calcium cyanamide has this disadvantage that the caustic dust is very annoying when it is being spread, and that its fertilizing action depends, more than for other nitrogenous fertilizers, upon the nature of the soil, the atmospheric conditions, the nature of the plant, and the method and time of use. The German demand for nitrogenous fertilizers In the next few years may be estimated at between 1,500,000 and 2,000,000 tons per year. The yield in ammonium sulphate of the German coke ovens may be estimated at approximately 500,000 tons, and this may be increased. In fact, it is likely that the production of ammonium sulphate at the coke works will be increased to 1,000,000 tons within a few years. Whether it will be possible readily to sell from 500,000 to 600,000 tons of fertilizer, in the form of calcium cyanamide, will depend in the first place upon the price, and also upon the competition created by the importation of saltpeter from Chile, and from Norway, and other fertilizers which are technically perhaps even more advantageous. Under the first head, we have to do here with ammonium compounds, and with their derivates prepared by the Haber process, the entire supply of which at the present is under government control. If the nitrogenous fertilizers, which are relatively cheaper than those obtained from carbide, should be set free again, the result would be that the large German factories of carbide and calcium cyanamide would have to look elsewhere for a market for their products.

<TT>*</TT>Reprinted from Automotive Industries, Jan. 8, 1920.

1921
The Journal of the AMERICAN SOCIETY of LUBRICATION ENGINEERS February edition page 8, PDF page 74

SCIENTIFIC LUBRICATION and LIQUID FUEL February
FOREST PRODUCTS as MOTOR FUELS<BR> By E. C. SHERRARD Government Chemist Probes Situation

<I>Much has been written about the possibilities of Ethyl Alchohol as a substitute for gasoline or rather perhaps, as a valuable auxiliary for blending purposes. The editor commends to the attention of the readers the following article written by a chemist of the Forestry Service, United States Department of Agriculture. It is quite complete in that it calculates the possible supply and what the addition to present production actually means.</I>

A discussion of forest products as motor fuels naturally resolves itself at once into a discussion of wood as a source of ethyl alcohol since at present alcohol is the only product obtainable from this source in sufficient quantity to render it worthy of consideration. It is true that wood is the source of methanol but when its fuel value and its limited production are considered it is at once eliminated as a possible motor fuel. The use of producer gas from wood is of course confined to certain localities where the cost of wood is low or the cost of coal is high and is necessarily limited to use in stationary engines. The adaptability of the volatile products resulting from the destructive distillation of wood as motor fuels have as yet not been investigated although their use for, such a purpose is not without the realm of possibility. Thus it may be seen that at the present time at least alcohol is the only motor fuel that the forests can offer. They can, however, supply a tremendous quantity of this material, notwithstanding the fact that the processes used for the production of sugars and alcohol from wood are far from being perfected. <BR> At every discussion of the prospective liquid fuel shortage the merits of ethyl alcohol as a motor fuel are strongly considered. True, there are some disadvantages connected with the use of this fuel but these disadvantages are more than counterbalanced by the fact that it is one fuel that may be obtained from a theoretically inexhaustible source. Whether this fact, carrying as it does a strong appeal to our imagination, has affected our better judgement or not, the fact remains that most of the synthetic fuels recently developed use this material as a base. <BR> Assuming that ethyl alcohol will ultimately be used as a motor fuel the transition from the fuels in use at the present time will be slow because of several factors. In the first place, the decrease in gasoline will be gradual due to the constant development of new fields and the development of better methods of cracking the higher hydro-carbons. In the second place, greater efforts will be made to obtain from other sources a fuel that more nearly approximates the one in use at the present time in order to utilize the present type of motor. As a greater demand develops alcohol will no doubt be used in admixture with gasoline, the quantity of alcohol in the mixture increasing proportionately as the quantity of gasoline or similar fuel decreases. Even though this transition is extremely slow too much stress cannot be laid upon the desirability of developing sources of alcohol capable of supplying the enormous demand.<BR> Granting, then, that the time will come when alcohol will be in demand as a motor fuel the question arises as to what will be the source of this material. The present sources are entirely inadequate to supply the enormous quantities that will be required for this purpose. The present demands for gasoline in this country require about four billion gallons per year. When it is considered that only 100,000,000 proof gallons of alcohol were produced in 1919 it can readily be seen that in order to meet the possible future demand this production must be increased about one hundred fold. Although the chief sources of alcohol are waste products, for instance cane and beet molasses, it is doubtful if even a billion gallons of alcohol can ever be produced from these and other waste materials without supplementing these with grains, potatoes or other starch containing material commonly used as food. Other large sources of sugar may be further developed as for instance the nipa palm of the Phillipines or the agave and cactus of Mexico but even these will supply but a portion to the total amount of alcohol required. The fact is that if alcohol is to become the future motor fuel all of these sources will be needed to supply the demand. In addition to the sources already enumerated there are two other sources that should receive consideration although here again neither alone or even both would be sufficient to supply the quantity of alcohol required. These two sources are wood and waste sulphite liquor. Although sugars are obtainable from or are present in these materials, they are difficult to isolate and purify because of the presence of other water soluble substances. In fact, the only practical means we have of removing the sugars from such a solution is by first fermenting them and then removing the alcohol so formed by distillation. <BR> Since wood or cellulose containing plants may be considered the largest potential source of ethyl alcohol a description of the processes used for the production and isolation of the sugars will undoubtedly be interesting. The processes used for the production of ethyl alcohol from wood may be grouped into two general classes: first, the hydrolysis of the wood into fermentable sugars by means of dilute mineral acids, and second, the solution of wood in concentrated acid with a subsequent hydrolysis of the solution by boiling with water. <BR> Processes of the first class have received by far the greater amount of attention and several plants have been built to use this method both in this country and abroad. The process consists, in general, of treating sawdust or shredded wood with a dilute mineral acid under 100 to 120 pounds steam pressure. The sugars thus formed are extracted, the acid removed by neutralization and the resulting sugar solution fermented. <BR> Processes of the second class involving the use of concentrated acid have not received commercial attention, notwithstanding the fact that cellulose can be converted to sugar and alcohol almost quantitatively. This apparent neglect is due to the excessive cost of the large quantity of concentrated acid required and the difficulty of completely recovering it. <BR> As before mentioned, the first mentioned process has proved to be the more promising of the two and the greatest development has taken place along this line. This development has been slow and many difficulties and even failures have been encountered. A brief history of this development is not without interest. <BR> From the time of Braccannot’s attempts to produce sugars and alcohol from wood in 1819 to Simonsen’s researches in 1898 but little progress was made although the subject received considerable attention. The investigations were carried out mostly with a view to the commercial application of the process and many important details were neglected that have since been found to have an important bearing upon the success of the operation. As a consequence the early literature upon the subject consists largely of patents although several papers did appear that contained fundamental information. The fact remains, however, that all of the early attempts to commercialize the process met with failure largely because of insufficient knowledge of the reactions involved and of the mechanical requirements of such an alcohol plant. The first investigations from a purely scientific standpoint were carried out by Simonsen upon both cellulose and sawdust. He used sulphuric acid as the catalytic agent and from his results concluded that the best conditions for the inversion are as follows:<BR> Time of inversion—1/4 hour<BR> Acidity. . . . . . . . . 0.5% sulphuric acid<BR> Proportion water to wood. . . . . . . .1:4<BR> Pressure. . . . . . . . . . . .9 atmospheres<BR> Working under these conditions he was able to convert about six per cent of the dry weight of the sawdust into alcohol. He was unable, however, to duplicate his results on a large scale although in a few exceptional cases he obtained slightly higher yields than those he obtained in the small auto-clave. Korner later substantiated his yield of six per cent and pointed out further that the sugar and consequently the alcohol yield were proportional to the cellulose content of the material digested. <BR> In 1900, A. C.Classen developed and patented a process for the conversion of sawdust into sugar in which an aqueous solution of sulphurous acid was used as the hydrolyzing agent. This process has without doubt played the leading role in the development of the process that is now generally used, although the original method has been entirely supplanted by the sulphuric acid process in this country. A plant was installed at d'Auberviller, France by a French company for the purpose of determining the commercial feasibility of the Classen process. The results were evidently satisfactory since the company increased its capacity shortly afterward and also decided to erect a still larger plant in the Vosges. Both of these plants were designed to use sulphurous acid but differed from the earlier ones in that the cooking was done by means of indirect steam. Another radical departure from the original methods was the method used for the neutralization and fermentation of the digested material. Instead of the sugar being extracted in diffusion batteries, the calcium carbonate and water were added directly to the digested sawdust and the whole mass fermented and distilled in the usual way. Although higher yields were claimed for this method as compared with the extraction method, the fact remains that the plant operated intermittently for only a short time and then shut down. <BR> In 1903, Classen disposed of his patent rights for America to the Classen Lignin Company of Chicago. After experimenting upon a semi commercial scale for some time, this company erected a plant at Hattiesburg, Miss., at a cost of about $250,000. This plant operated upon longleaf pine but after a short period of operation failed because of mechanical and technical difficulties. The chief disadvantages of the process were first, four to six hours were required to convert 1% to 2 cords of wood, second, an extremely large quantity of acid was required, third, the prolonged heating caused the wood to be reduced to a fine powder which rendered extraction difficult while at the same time large quantities of sulphuric acid were formed with a consequent caramelization of the sugars produced, fourth, the digesters were lead lined and the buckling and breaking of the lining was a great source of delay and expense. <BR> Ewan and Tomlinson who were associated with the Classen process overcame most of these difficulties by using gaseous sulphur dioxide and cooking with direct steam. They were thus able to shorten the cooking period to forty-five minutes and to reduce the quantity of acid required. They also succeeded in constructing a digester that was not affected by the extreme conditions required by the process. In 1909 Ewan and Tomlinson were granted a patent covering the use of sulphuric acid as the catalytic agent, the cooking conditions being practically the same as those suggested by Simonsen several years before. The use of sulphuric acid removed many of the technical difficulties that had been previously experienced and the Standard Alcohol Company, with whom Ewan and Tomlinson were then associated, erected a plant at Georgetown, South Carolina. This plant was later acquired by the DuPont Company and operated intermittently until 1913 when a fire destroyed the saw mill of the Atlantic Coast Lumber Company from which the alcohol plant received its saw dust and wood waste. The sawmill was rebuilt in 1914 and the alcohol plant has operated successfully since that time. After disposing of the alcohol plant to the DuPont Company, the Standard Alcohol Company underwent a reorganization and interested some foreign capital in the erection of a plant of 5,000 gallon daily capacity at Fullerton, La. This plant was never operated successfully by the Standard Alcohol Company because of financial difficulties caused by the war. The lease was later acquired by American interest under the name of the Standard Lessee Corporation, who operated the plant for some time in order to assure themselves of the commercial applicability of the process. In 1917 they purchased the plant and have operated it continuously since that time except for short intervals when the supply of wood waste was insufficient to warrant operation. It is our understanding that this plant is now closed due to a curtailment of lumbering operations by the sawmill that was furnishing the wood waste. <BR> One other effort was made several years ago to establish the industry in this country by the Classen Chemical Company. Western capital was interested in the erection of a plant at Port Hadlock in Puget Sound for the production of ethyl alcohol and stock food from sawdust obtained from mills at Seattle, Tacoma, Everett, Anacortes and Port Blakely. This plant was equipped with six digesters of the same size and shape as those used in the French plant previously referred to. They were of the tubular type and the cooking was carried out by means of indirect steam. Sawdust and enough water were added through a manhole into the space between the tubes to raise the moisture content to about 45 per cent. Sulphur dioxide was then admitted and the mixture cooked at 75 to 100 pounds steam pressure. The cost of conversion was extremely high, first, because the corrosion of the digesters was very rapid, second, because the time necessary to heat by indirect steam was very long and, third, because it was necessary to replace the low pressure steam in the outer jacket with high pressure steam to prevent the sulphurous acid from leaking out into the outer jacket. The extraction apparatus was also far from efficient but this did not cause any concern because the extracted sawdust was later mixed with Hawaiian molasses and after drying, sold as a cattle food. In addition to the difficulties already enumerated the plant was located some eighty miles from a railroad which greatly increased all transportation charges both to and from the plant. This fact, coupled with the poor design of the digester and extraction equipment were the leading factors responsible for the failure of this plant. <BR> The fact that the process encountered so many difficulties in its transition from the experimental stage to the commercial application led the Forest Products Laboratory into a more detailed study of the many factors involved. Several years ago the laboratory installed apparatus having a capacity of about one-hundred and fifty pounds per cook and since that time about two hundred cooks have been carried out under varying conditions. Some of the previous work has been duplicated and many advances have been made. <BR> The greatest fault common to all the work that has been done heretofore is that the investigators were concerned chiefly with the increase in yield of the total sugars obtained, whereas, such increase does not necessarily mean that the alcohol yields increase proportionately. Without accurate fermentations and consequently without complete data the interpretation of results led to difficulty since in many cases the quantity of total sugar gives no indication of the quantity of alcohol obtainable. Since we have no good quantitative chemical means for separating the fermentable and non-fermentable sugars but must depend upon a biological process it has also became necessary to carefully standardize the fermentation procedure. The results obtained from these carefully standardized fermentation experiments more than emphasized the importance of this step. <BR> Another reason that so much of the early data was contradictory is due to the fact that many of the investigators used different amounts of acid solution of constant strength, thereby varying both the ratio of water to wood and acid to wood. It has been learned that these variables are not mutually dependent and that the “acidity” of the solution itself is of minor importance, except where it varies the actual ratio of acid to wood, and that the concentration of the catalytic agent, expressed in percent of the dry wood substance, is the decisive factor. <BR> In view of these facts it was thought wise to reinvestigate certain variables already studied in addition to others that might have a bearing upon the technical solution of the problem. <BR> The variables that have been studied are: <BR> 1.	The influence of temperature and pressure.<BR> 2.	Length of time of digestion.<BR> 3.	Ratio of water to dry wood.<BR> 4.	Ratio of catalyst to dry wood.<BR> 5.	Concentration of catalyst in water.<BR> 6.	Size of sawdust, shredded waste, etc.<BR> 7.	Variation of yields from different species and mixtures.<BR> 8.	A study of fermentation variables.<BR> From these investigations it has been learned that if the pressure and temperature are varied the quantity of sugar produced increases with an increase in pressure until the total sugar produced corresponds to about 23 percent of the dry weight of the wood. This increase occurs until a pressure of 7.6 atmospheres corresponding to a temperature of 174 degrees C has been reached after which a decrease in the yield of total sugar is noted. Although this decrease in total sugar is quite marked the quantity of fermentable sugar continued to increase indicating that as more of the non-fermentable sugar is destroyed more cellulose is hydrolyzed with the production of fermentable sugar. It might be well to point out that under most conditions an equilibrium is finally reached and that beyond that point no further increase in sugar production is obtainable. This point is reached when about 25 percent of sugar is formed, regardless of whether they are pentose or hexose sugars. At pressures greater than 7.5 atmospheres or temperatures greater than 175 degrees C even the hexose sugar breaks down quite rapidly. Neuman speaks of 175 degrees C as the “critical point” and claims that technically it is needless to investigate the production of sugar at higher temperatures.<BR> By holding the pressure, ratio of water to wood and acid concentration of acid constant and varying the time of cooking it was found that the best results were obtained from a 10 to 15 minutes cook. This holds for concentrations of acid corresponding to 1.4 to 2.5 per cent of the dry wood and for ratios of water to wood of 1.25 to 1 up to 4 to 1. It was found that the reaction was practically complete when a pressure of 115 pounds was reached but that by continuing the reaction for a few minutes a slightly larger yield of fermentable sugar was obtainable. The influence of different ratios of water to wood was studied by holding the other variables constant and varying the quantity of water added. The quantity of water within the limits of four parts of water to one part of wood and equal parts water and wood has very little effect upon the sugar or alcohol production. Although equal parts gave as good results as larger amounts it was found that 1.25 parts of water to 1 of wood was the most desirable ratio. This ratio assures a good mixture of water and wood and causes less difficulty in handling the digested material by eliminating the drip caused by larger proportions. <BR> Another series of experiments was conducted in which the concentration of sulphuric acid to dry wood was varied while the other variables were held constant. It was found that for spruce the alcohol yield increased rapidly with slight increases in the acid concentration for concentrations below one per cent of the dry wood. As the concentration of acid was increased from one per cent to four percent practically no difference in alcohol yield was noted. With short leaf pine an actual decrease occurred with concentrations of acid greater than 2.5 per cent of the dry wood. As regards total sugars a rapid increase was noted until a concentration of 1.25 per cent acid was reached after which the total sugar dropped as the quantity of acid was increased. As in the case of the other variable an increase of acid caused a slight but constant increase in the quantity of total sugar fermentable. Between the limits of one part of water to one of wood and four parts of water to one of wood no difference was noted in the effect of an acid of a given strength. In other words, the quantity of water present between these limits has very little effect upon the reaction. <BR> From the foregoing it will be seen that the ideal conditions for the conversion of sawdust to sugar are, a ten to fifteen minutes cook at 7.5 atmospheres pressure with a ratio of 1.25 parts of water to one of wood and a concentration of sulphuric acid corresponding to about 2.0 percent of the dry wood. When soft woods are treated under such conditions yields of sugar corresponding to 20 to 25 per cent of the dry weight of the wood can be obtained. In the case of hardwood the yields are considerably less, in most cases amounting to 12 to 14 percent of the dry wood. Since the hardwoods have received but little attention as yet there is a possibility that these yields may be increased by further experimentation. At the present time, however, the soft woods are the only ones that are being used or investigated. <BR> The soft wood yields in terms of alcohol correspond to about eight per cent alcohol when calculated upon the dry weight of the wood. Longleaf pine, for instance, will yield about 25 percent of total sugars of which about 75 percent are fermentable. This yield is equivalent to 24 to 25 gallons of 190 proof alcohol per ton of dry wood. While this paper deals only with the use of dilute sulphuric acid as the hydrolyzing agent several others have been investigated to a limited extent. It has been found that hydrochloric and phosphoric acids give practically the same results under the conditions previously mentioned. Some difficulty is met within the use of hydrochloric acid, however, since the salts formed during neutralization interfere with the action of the yeast. It has also been found that nitre cake or a mixture of nitre cake and sulphuric acid equivalent to 18 percent sulphuric acid gives very good results. Other salts such as sodium chloride, potassium chlorate and ferrous sulphate, when used with sulphuric acid, give good yields of sugar but in most cases the presence of the salts interfere with the final fermentation. <BR> In regard to the size of the wood particles best suited to this process it has been found that a mixture of sawdust and shredded slabs and edgings give the best results. Chips varying from 1/8 to 5/8 inch are completely penetrated and give yields of sugar comparable with those obtained from sawdust. Sawdust alone is difficult to leach and it has been found that a mixture of the two is much more readily handled and give the best results in the extraction battery. This extraction of the sugar on a large scale production is carried out in the same way and in the same kind of extraction cells as in the beet sugar industry. An extraction amounting to about 96 per cent of the total sugars is ordinarily obtained. It is interesting to note that the non-fermentable sugars are the first to be removed and that the fermentable sugars extract with more difficulty. In this connection it should be noted that a large proportion of bark should be avoided since practically no sugar is derived from it and the presence of it causes an unnecessary handling of a large volume of material from which little return is forthcoming. The presence of ten per cent or less of bark causes no appreciable decrease in the sugar and interferes but slightly with the plant operation. <BR> The species investigated include all of the soft woods that are cut in sufficient quantities to produce enough waste to warrant the erection of a plant. With but one exception the yield of alcohol from these different woods averages about 23 gallons of 190 proof alcohol. The one exception is western larch which produces almost 30 per cent of sugar. This sugar, however, consists largely of galactose which is difficult to ferment under ordinary conditions so that of the total sugar obtainable only forty per cent is fermentable. This, of course, eliminates this wood as a possible raw material, although it is possible that better methods can be devised by means of which a larger part of the sugar can be converted into alcohol. The hard woods cannot be considered as a source of alcohol at present because of the extremely low sugar yields. It should be pointed out, however, that the broad leaved woods are not with out promise since the yield of volatile acids from these are much greater than from the coniferous woods. <BR> A word concerning the fermentation of the sugars may be of interest. As soon as the digestion is complete the sugars are extracted from the residue and the acid neutralized with lime or calcium carbonate. After settling the liquor is ready for fermentation. Since the yeast will not develop in this solution it is necessary to first grow it in molasses. A small quantity of sugar liquor containing malt sprouts, ammonium sulphate and a small quantity of ammonium phosphate or phosphoric acid is then added as a yeast nutrient and the whole allowed to stand for about six hours. From then on two additions are made every three hours and then one every hour until the tub is filled. Thus it requires about thirty hours to fill a tub. By that time the fermentation is proceeding vigorously and is allowed to continue for the remainder of the 96 hour period after which time the liquor is ready for distillation. If we consider the fermentation efficiency as the quantity of sugar that disappears during fermentation and is obtained as alcohol the method shows an efficiency of about 90 to 94 per cent, which, I think, is considered fair in practice. By the use of this method it is very easy to duplicate our experiments and remarkably concordant results have been obtained. I regret that time prohibits a more detailed discussion of this very interesting phase of the work. <BR> Just a few words in regard to the materials available for the production of ethyl alcohol by the application of this process. We, of course, realize that if the time ever comes when alcohol will be used as commonly and in as large quantities as gasoline is today, the available wood waste will be far from sufficient to meet the demands. It will, however, be a source that cannot be ignored since from the waste a larger quantity of alcohol is obtainable than is being produced from other sources at the present time. I wish to emphasize the applicability of this or similar processes to other cellulose containing plants in case the demand for alcohol should ever exceed the quantity obtainable from the sources now in general use. It may at some future time be desirable to cultivate highly prolific, rapid growing plants having a relatively high cellulose content for conversion into alcohol. While this statement may seem a little far fetched it is well to consider that more alcohol is obtainable from a ton of dry wood than from a ton of sugar cane containing 75 per cent juice of which 14 per cent is fermentable. Of course there is the possibility that it will be found more economical to grow some sugar producing plant such as cane or sorgum, but the disadvantages, such as the short operating season, partly outweigh the advantages to be gained. Thus it will be seen that cellulose containing plants constitute as good a source of alcohol as any other if we except the waste materials now used such as crude molasses, or the more expensive starch containing foods. What plants would be best suited for this purpose is not known because few have been investigated from this standpoint. All cellulose containing plants are not adaptable to the process since some, such as the cane fibre itself which remains after the expression of the juice, gives rise under this treatment to a large quantity of pentose sugar and only a small quantity of fermentable sugar.<BR> Of the wood waste available only the mill waste has so far been considered since at present the cost of gathering the woods waste is prohibitive. <BR> About 25 per cent of the volume of the forest is left in the woods in the form of stumps, tops, limbs and small and defective trees and represents a volume of about 23,700,000 cords (100 cu. ft.of solid wood per cord.) Approximately 75 percent of the cut over forest comes to the mill in the form of logs of which 53 per cent is waste or on a basis of 100 cu. ft. of solid wood per cord, a total of 37,900,000 cords per year. This makes a total of woods and mill waste of 61,600,000 cords per year or almost 2-3 of the volume of the cut over forest. This is “primary waste” or waste in converting trees to rough lumber and does not include waste caused in dressing the lumber or “secondary wastes” such as result in working the lumber into finish ed products like furniture, house trim, flooring, vehicles, etc.<BR> The amount of waste available for alcohol production is dependent upon the efficiency of the mill in working the waste material over in to useful products. Of the cubical contents of a tree the following is wasted:<BR> Stumps. . . . . . . . . . . . . . . . . . . . . . 2%<BR> Tops. . . . . . . . . . . . . . . . . . . . . . . .18%<BR> Sawdust. . . . . . . . . . . . . . . . . . . . .12%<BR> Bark. . . . . . . . . . . . . . . . . . . . . . . . 10%<BR> Slabs. . . . . . . . . . . . . . . . . . . . . . . . 8%<BR> Edgings. . . . . . . . . . . . . . . . . . . . . . 8%<BR> Shavings. . . . . . . . . . . . . . . . . . . . . 4%<BR> The annual cut of lumber in the United States for the last five or six years is approximately 40,000,000,000 ft. b. m. The mill waste from this cut has been estimated by Margolin  as follows:<BR> Saw log. . . . . . . . . . . . . . . . . . .100.0%<BR> Bark. . . . . . . . . . . . . . . . . . . . . . 13.0%<BR> Edgings and trimmings. . . . . . . . .8.7%<BR> Slabs. . . . . . . . . . . . . . . . . . . . . . .8.7%<BR> Careless manufacturing and accidents. . . . . . . . . . . . . . . . . . . .3.5%<BR> Loss in cutting standard widths and lengths. . . . . . . . . . . . . . . . . .1.7%<BR> Total. . . . . . . . . . . . . . . . . . . . . . 49.1%<BR> Lumber. . . . . . . . . . . . . . . . . . . . 50.9%<BR> For each thousand feet of lumber produced at the mill (equivalent to 83.3 cu. ft. solid wood)

we have, according to the above table 80 cu. ft. of waste. This waste is distributed as follows:<BR> Bark. . . . . . . . . . . . . . . . . . . . 21.3 cu. ft.<BR> Sawdust. . . . . . . . . . . . . . . . . 22.<BR> Edgings and trimmings. . . . . .14.2<BR> Slabs. . . . . . . . . . . . . . . . . . . .14.2<BR> Careless manufacturing and accidents. . . . . . . . . . . . . . . . 5.6<BR> Loss in cutting to standard. . . .2.7<BR> 80.0 cu. ft.<BR>

After deducting the bark this leaves in the form of waste 58 cu. ft. of solid wood per thousand feet of lumber cut or 2,320,000,000 cu. ft. annually. As the average weight of air dried wood is about 35 pounds this amounts to 40,000,000 tons. It is estimated that one-half of this is utilized by reworking and for fuel, the other one-half being absolute waste. <BR>

The Journal of the AMERICAN SOCIETY of LUBRICATION ENGINEERS February edition page 8, PDF page 74

TECHNOLOGY OF CELLULOSE ESTERS
The study of the hydrolysis of cellulose has engaged the attention of chemists for over a cent ury, as far back as 1797. A. Fourcroy and Vauquclin2 having published a memoir upon this subject, which twenty-two years later was made the basis of an investigation by H. Braconnot.3 The interest in the problem is due not only to the possible economic utilization of the resulting products, but also to the theoretical

1. Cf. C. A. 1919, 13, 1209, line 20. 2. Ann. Chim. Phys. 1797, (1), 23, 186, 203; Nicholson J. 1797, I, 385; Trommsdorff, J. Pharm. 1797, 6, 172, 189. 3. Ann. Chim. Phys. 1819, (2), 12, 172; abst. Dingl. Poly. 1820, 1, 312; 1827. 25, 81 ; Gilb. Ann. 1819, 63, 348; Edin. Phil. J. 1820, 2, 363; J. dc Pharm. 1820, 6, 416; Quart. J. Sci. 1820, 8, 386; Schw. J. 1819, 27, 328. Tilloch, Phil. Mag. 1820, 55, 53, 118. Sec also Nancy, Trav. Soc. Sci. 1819-1823, 66; Gilb. Ann. 1822, 70, 389; Giorn. Arcad. 1820, 6, 277; Quart. J. Sci. 1820, 9, 392.

importance of the reactions as possibly furnishing a satisfactory solution of the structure of the cellulose complex, for the products obtained were crystalline and hence readily purified in contra distinction to cellulose, which in all forms is amorphous. The work of Braconnot was followed by that of J. Arnould,1 M. Pettenkofer,2 Tribouillet,3 Pelouze,4 G. Melsens,5 F. Varrentrapp, 6 A. Payen,7 H. Ludwig,8 H. Tauss,9 J. Matheus,10 C. Amos and W. Anderson,11 J. Poumarede and I*. Figuer,12 as well as, 1. Compt. rend. 1854, 39, 807; Dingl. Poly. 1854, 134, 219; Poly. Notiz. 1855, 31; Wag. Jahr. 1855. 1, 221; Instit. 1854, 366; Arch. ph. Nat. 27, 331. See also Tribouillet, Mon. Ind. 1854, 908; Dingl. Poly. 1854, 134, 316; Poly. Centr. 1855, 21, 128; Wag. Jahr. 1855, 1, 221. Melsens, Genie. Ind. 1855, 106; abst. Dingl. Poly. 1855, 138, 426. 2. Bayer Kunst. u. Gewerbebl. 1855, 136; Dingl. Poly. 1855,136, 387; Poly. Centr. 1855, 21, 955; Poly. Notiz. 1855, 10, 161; Wag. Jahr. 1855, 1, 222; Poly. Centr. 1855, 21, 955; Pharm. Centr. 1855, 26, 557. 3. Mon. Ind. 1854, 1908; Dingl. Poly. 1854, 134, 316; Poly. Centr. 1855, 21, 128; Wag. Jahr. 1855, 1, 221 ; Compt. rend. 1854, 39, 980. 4. Compt. rend. i859, 48, 327, 1027; abst. Mon. Sci. 1859-1800, 2, 86, 131; Poly. Centr. 1859, 25, 976; Dingl. Poly. 1859, 151, 394; Jahr. Chem. 1859, 12, 533;J. pharm. 1859, 35, 209; Instit. 1859, 49; Rep. Chim. Pure, 1, 272. See also Weil, Compt. rend. 1859, 48, 1027. Payen, Dingl. Poly. 1855, 138, 58. W. Stein, Poly. Centr. 1855, 21, 429. A. Hofmann and Redwood, Pharm. J. Trans. 14, 556; 15, 28; Chem. Soc. Quart. J. 1855, 8, 120. Robinet, J. Pharm. (3), 27, 191. Campani, Cimento, 2, 210. Rabourdin, J. Pharm. (3), 28, 68; Vierteljahrsehr pr. Pharm. 5, 406; Jahr. Chem. 1854, 7, 797. Walz, N. Jahr. Pharm. 3, 217. H. Ludwig, Arch. Pharm. (2), 82, 22; Pharm. Centr. 1855, 26, 512. Bordier, Dingl. Poly. 1855, 136, 387. 5. Genie industr. 1855, 106; Dingl. Poly. 1855, 138, 426; Wag. Jahr. 1855, I. 221 ; Poly. Centr. 1856, 22, 873. 6. Mitth. f. Gewerbever. des Herzogthums, 1865, 70; Dingl. Poly. 1866, 181, 233; Wag. Jahr. 1866, 12, 466; Braunschweig. 1866, 73; Deut. Ind. 1866, 366; Poly. Centr. 1866, 32, 1 150. 7. Compt. rend. 1867, 64, 1167; Dingl. Poly. 1867, 185, 308; Chem. Centr. 1868, 13, 20; Jahr. Chem. 1867, 952, 953; Mon. Sci. 1868, 10, 322; Poly. Centr. 1867, 33, 1351. See also Payen, Ann. Chim. Phys. 1866, (4), 7, 382; Zts. Chem. 1866, 334. Bachet and Marchard, Jahr. Chem. 1866, 19, 663; Van Tieghem, Compt. rend. 1863, 56, 963; abst. Jahr. Chem. 1863, 16, 565; Chem. Centr. 1863, 34, 950. 8. Zts. f. deutsche Landwirthe, 1855, 192; Dingl. Poly. 1855, 138, 80; Poly. Centr. 1855, 21, 1085; Poly. Notiz. 1855, 10, 286; Wag. Jahr. 1855, 1, 223. 9. Dingl. Poly. 1889, 273, 276; 1890, 276, 411; abst. Chem. News, 1890, 61, 169; J. S. C. I. 1889, 8, 913; Mon. Sci. 1890, 55, 164; Ber. 1889, 22, R, 769; Chem. Centr. 1889, 60, II, 444; Chem. Ind. 1889, 12, 514; Chem. Tech. Rep. 1890, II, 105; Jahr. Chem. 1889, 42, 2838; Wag. Jahr. 1889, 35, 1; Apothker Ztg. 1890, 232; J. S. C. I. 1890, 9, 883; Mon. Sci. 1891, 38, 1264; Ber. 1891, 24, R, 277; Chem. Centr. 1890, fit, II, 187; Jahr. Chem. 1890, 43, 2189, 2873; 1891, 44, 2811; Wag. Jahr. 1890, 36, 1148. 10. Dingl. Poly. 1893, 287, 91; abst. Jahr. Chem. 1893, 46, 647. 11. Mechanics Mag. 1866, 341; abst. Dingl. Poly. 1867, 184, 308; Jahr. Chem. 1867, 20, 953. Chaudet and Delamure-Debouteville, F. P. 123556, 1878; abst. Chem. Ind. 1878, 1, 421 ; Mon. Sci. 1879, 21, 1042. 12. Compt. rend. 1846, 23, 918; 1847, 25, 17; abst. J. prakt. Chem. TECHNOLOGY OF CEU.ULOSE ESTERS J. Sacc,1 F. Schulze,2 H. Mohl,3 E. Fremy4 with Terreil5 and Urbain,5 F. Bente,7 J. Erdmann,8 A. Stutzer,9 H. Kolbe,10 Flechsig,11 G. 1847, 42, 25; Berz. Jahr. 1849 ; 28, 340; Jahr. Chem. 1847-1848, 1, 797; Rev. Sci. 1847, 14, 68; Ann. 1847, 64, 387; Annuaire de Chim. 1847, 453; J. Pharm. 1847, (3), 11, 81 ; Rep. Pharm. (2), 47, 344;Soe. Philom. Proc. Verb. 1846, 130. 1. Ann. Chim. Phys. 1849, (3), 25, 218; abst. Jahr. Chem. 1849, 2, 473, 688, 704; J. prakt. Chem. 1849, 46, 430; Pharm. Centr. 1849, 20, 235; Chem. Gaz. 1849, 274. See also J. Sacc, Ann. Chim. Phys. 1849, (3), 27, 473; J. prakt. Chem. 1850, 49, 296; Pharm. Centr. 4850, 21, 91; Jahr. Chem. 1849, 2, 704; J. Pharm. 1849, 16, 293. 2. Chem. Centr. 1857, 28, 321; Jahr. Chem. 1857, 10, 491. See also Mitscherlich, Berl. Acad. Ber. 1850, 102; Ann. 18.50, 75, 305; J. prakt. Chem. 1850, 50, 144; Pharm. Centr. 1850, 21, 385; Chem. Gaz. 1851, 61; Instit. 1850, 228; Jahr. Chem. 1850, 3, 541. E. Schulze, Ber. 1890, 23, 2579; abst. J. C. S. 1890,58, 1456; Chem. Centr. 1890,61, 1, 650; J. S. C. I. 1890,19,1051. 3. Flora, 1840, 23, 609, 625; Ann. Sci. Nat. 1841, 15, 38. 4. Compt. rend. 1859, 48, 202, 862; 1876, 83, 1 136. N. J. Pharm. 35, 81 ; abst. Rep. Chim. Pure, 1859, 1, 269; Compt. rend. 1859, 48, 325, 360, 667, 862; J. Pharm. 35, 321, 401 ; abst. Inst. 1859, 121, 151 ; Rep. Chim. Pure, 1859, 1, 357, 433; Pharm. Vierteljahr. 9, 221; N. J. Pharm. Inst. 1859, 357; Rep. Chim. Pure, 1859, 1, 602; Chem. Centr. 1860, 4; Compt. rend. 1859, 49, Ml; Jahr. Chem. 1859, 12, 529, 530, 532, 533, 534, 537, 540; Bull. Soc. Chim. 1877, 28, 174; Ber. 1877, 10, 90. 5. Compt. rend. 1868, 66, 456; Bull. Soc. Chim. 1868, 9, 436; Ber. 1877, 10, 90; J. pharm. Chim. 1868, 7, 241; abst. Chem. Centr. 1868, 39, 616; Jahr. Chem. 1868, 21, 762. 6. Compt. rend. 1882, 94, 108; Ann.sci.nat. 1882. f6), 13, 353; abst. J. C. S. 1882, 42, 708; J. S. C. I. 1882, 1, 113; Bull. Soc. Chim. 1882, 37, 409; Jahr. Chem. 1882, 35, 1150. 7. Ber. 1875, 8, 476; Landw. Yersuchstat. 1876, 19, 164; abst. Bull. Soc. Chim. 1876, 25, 278; Chem. Centr. 1875, 46, 392; Chem. Tech. Rep. 1875, 14, I, 16; Dingl. Poly. 1875, 217, 235; Jahr. Chem. 1875, 28, 785; Wag. Jahr. 1875, 21, 1045; Jahr. rein Chem. 1875, 3, 382. 8. Ann. I866, 138, 1; Ann. Suppl. 1867, 5, 223; abst. Bull. Soc. Chim. 1866, (2), 6, 340; 1868, (2), 10, 295; Chem. Centr. 1866, 37, 401; 1868, 39, 395; Jahr. Chem. 1867, 20, 672, 738; Zts. Chem. 1868, 155, 245; J. Pharm. (4), 3, 478. Jahr. rein Chem. 1875, 3, 382. 9. Ber. 1875, 8, 575; abst. Bull. Soc. Chim. 1876, 25, 471 ; Jahr. Chem. 1875, 28, 822. A. Stutzer, D. R. P. 215273, 1908; Pap. Ztg. 1909, 34, 3758; abst. C. A. 1910, 4, 628; Chem. Zentr. 1909, 80, II, 1783; Chem. Ztg. Rep. 1909, 33, 600; Wag. Jahr. 1909, 55, I, 291. F. P. 402871, 1909; abst. J. S. C. I. 1909, 28, 1323. Des. Deut. Naturforscher und Aerzte Sept. 1909; abst. Zts. ang. Chem. 1909, 22, 1999; J. S. C. I. 1909, 28, 1162; Bull. Soc. Chem. 1910, (4), 6, 222; Jahr. Chem. 1909, 62, II, 387; Meyer Jahr. Chem. 1909, 19, 323. 10. J. prakt. Chem. 1880, (2), 21, 443 ; 22, 112; abst. Oest. Ung. W. u. Agr. Ztg. 11, 241 ; J. C. S. 1880, 38, 520; 1881, 40, 212; Bull. Soc. Chim. 1880, 34, 96; Ber. 1880, 13, 1142, 1759; Chem. Centr. 1880, 51, 358, 501; Chem. Tech. Rep. 1880, I, 19, 444; Chem. Ztg. 1880, 4, 488; Jahr. Chem. 1880, 33, 1063; Jahr. rein Chem. 1880,8,369; Wag. Jahr. 1880, 2S, 454; Zts. Chem. Grossgewerbe, 1860, 5, 119, 135, 151, 308. 11. Zts. physiol. Chem. 1883, 7, 523; abst. Ber. 1883, 16, 2508; Chem. Tech. Rep. 1883, 22, II, 144; Jahr. Chem. 1883, 36, 1363; Wag. Jahr. 1883, 29, 681; Tech. Chem. Jahr. 1883-1884, 6, 275; Zts. Deut. Spiritusfabr. 1883, 805. CELLULOSE 197 Mulder,1 F. Hoppe-Seyler,2 T. Thomsen,3 F. Koch,4 A. Ihl,5 M. Singer,6 and others7 previous to 1895. Notwithstanding the 1. Scheik. Onderzoek, 2, 76; abst. J. prakt. Chem. 1844, 32, 336; Ann. 1841, 39, 150. 2. Ber. 1871, 4, 15; abst. J. C. S. 1871, 24, 226; Chem. Centr. 1871. 42, 84; Jahr. Chem. 1871, 24, 476; Bull. Soc. Chim. 1871, 15, 98; Chem. News, 1871, 23, 131. See G. Foch, Chem. Ztg. 1913, 37, 1221. R. McKec, Paper, 1919, 25, 25, 34. 3. J. prakt. Chem. 1879, 127, 146; abst. Ind, Blatter 1879, 402; Arehiv. Pharm. 9, 557; J. C. S. 1879, 36, 613; J. S. C. I. 1883, 2, 89; Bull. .Soc. Chim. 1880, (2), 33, 494; Ber. 1879, 12, 1012; Chem. Centr. 1879, 50; Dingl. Poly. 1879, 233, 413; Jahr. Chem. 1879, 32, 896; Jahr. rein Chem. 1879, 7, 503; Wag. Jahr. 1879, 25, 1155. See also Scheibler, Ber. 1873, 6, 612; abst. Jahr. Chem. 1873, 26, 829. 4. Pharm. Zts. Russ. 25, 619, 635, 651, 667, 683, 699, 730, 747, 763; abst. Ber. 1887, 20, 145; Wag. Jahr. 1887, 33, 1. 5. Chem. Ztg. 1885, 9, 231, 451, 485; 1887, 11, 19; abst. Chem. News, 1885i 51, 114; J. C. S. 1885, 48, 694; 1887, 52, 534; J. S. C. I. 1887, 6, 306; Ber. 1885, 18, 128; 1887, 20, 77 R; Chem. Centr. 1885, 56, 761; Chem. Ind. 1888, 11, 188; Chem. Tech. Rep. 1885, 2*, I, 258; II, 17; 1887, 26, II, 329; Dingl. Poly. 1887, 266, 597; Jahr. Chem. 1887, 40, 2642; 1885, 38, 1977; 1886, 39, 1971.* See also H. Molisch, Monatsh. Chem. 1885, 7, 198; abst. Jahr. Chem. 1886, 39, 1971, 2172; Dingl. Poly. 1886, 261, 135. 6. Monatsh. 1882, 3, 396; abst. J. C. S. 1882, 42, 1122; J. S. C. 1. 1882, 1, 404; 1883, 2, 89; Ber. 1882, 15, 2272; Chem. Tech. Jahr. 1883, 22, I, 243; Chem. Ztg. 1882, 6, 603, 813; Wag. Jahr. 1882, 28, 1060; Akad. Wissensch. Wein, 1882, 100; Tech. Chem. Jahr. 1892-1893, 5, 212. 7. T. Seliwanoff, Ber. 1887, 20, 181; abst. J. C. S. 1887, 52, 459; Bull. Soc. Chim. 1887, (2), 48, 135; Ber. 1887, 20, 181; Chem. Ztg. 1887, 11, 1486; Jahr. Chem. 1887, 40, 2301; Landw. Ver.-Stat. 34, 414. See also Chem. Ztg. 1885, 9, 231. C. Wurster. Ber. 1887, 20, 808, 3195; abst. J. C. S. 1887. 52, 620; J. S. C. I. 1887, 6, 565; Chem. Ind. 1888, 11, 90; Chem. Tech. Rep. 1887, 26, I, 188; II, 350; Jahr. Chem. 1887, 40, 2467; Industriblatter, 1887, 119. E. Siegle, J. prakt. Chem. 1856, 69, 148; Poly. Centr. 1856, 22, 206; Wag. Jahr. 1856, 2, 225. Roy, Ann. Soc. Linn. Paris, 1826, 219; Jour. f. oeken Chem. 1, 215. Baer, Physikal. Lexicon, 1859, 6, 849; Wag. Jahr. 1859, 5, 401. Koerner, Diss. Dresden, 1907; Zts. ang. Chem. 1908, 21, 2353. Gottlieb, J. prakt. Chem. 1883, (2), 28, 385. Harpf, Pap. Ztg. 1891, 1845. Chudiakow, Landw. Jahr. 1894, 23, 391. Giltay and Anderson, Jahr. Wiss. Bot. 1894, 26, 543. Hansen, Medd. Carlsberg Labor. 1881, 2. Iwanowsky, Bot. Centr. 1894, 58, 344. Pederson, Pap. Ztg. 1890, 422. For data on obtaining ethyl alcohol from sulfite solution as in wood pulp manufacture, consult, E. Haegglund, Pulp Paper Mag. 15, 1125, 1157; E. Hendrick, Met. Chem. Eng. 1918; Papers Makers Monthly, 1918, 56, 136; Paper, 22, No. 4, p. 13. A. White and J. Rue, Paper Makers Monthly, 1917, 55, 109, 146; Met. Chem. Eng. 1917, 9, 182. G. Stlele, Worlds Paper Trade Rev. 66, No. 25, p. 12. E. Oman, Pap. Fab. 13, 534. V. Krieble, Paper, 23, No. 23, p. 153; Pulp Paper Mag. 17, 116. Paper Makers Monthly, 1918, 56, 136, 230, 235, 238, 359. Can. Chem. J. 2, 211. Paper, 21, No. 17, p. 16, 30; No. 18, p. 13; No. 19, p. 11; No. 20, p. 15. V. Krieble, Paper, Ann. Conv. No. 1919,23, 153; abst. J. S. C.I. 1919,38, 571-A F. Storer, Bull. Bussey Institution, 1900, 2, (9) ; abst. J. S. C. I. 1901, 20,822. G. Pradel, F. P. 385015, 1907; abst. J. S. C. I. 1908, 27, 516. G. Mezzadroli, Boll. Chim. Farm. 1918, 57, 360-62; abst. J. S. C. I. 1919, 38, 50-A. F. La Forge, U. S. P. 1288429, 1918; abst. J. S. C. I. 1919, 38, 154-A. R. Kocher, E. P. 107219, 1916 (appl. No. 7339 of 1916); abst. J. S. C. I. 1917, 36, 973. H. Landmark, First Addn. dated May 20, 1914 to F. P. 198 TECHNOLOGY OF CELLULOSE ESTERS extensive nature of this pioneer work, but little real progress had been made toward establishment of the data accumulated upon a firm commercial manufacturing basis. The most complete study of the saccharification of cellulose published up to that time is contained in a series of papers by E. Simonson in 1898,1 who embodied his results in a patent.2 He worked only on wood cellulose with the objective of the manufac ture of industrial ethyl alcohol,3 and found the most favorable conditions for the saccharification of 40 gm. of celluose to be a 2 hours digestion at 6-8 atmospheres pressure with 1080 cc. of 0.5% sulfuric acid, longer digestion causing a serious destruction of sugar. His results are epitomized in the following two tables, in which table 10 shows the amounts of (/-glucose formed with sul furic acid of varying concentrations after four hours treatment under the pressures stated: 456871, 1913. (J. S. C. I. 1913, 32, 1063); abst. J. S. C.' I. 1915. 34, 488. Chem.-Ztg. 1915, 39, 98-99; abst. J. S. C. I. 1915, 34, 275. F. P. 456871, 1913; abst. J. S. C. I. 1913, 32, 1063. T. Norton, U. S. Cons. Reps. Nov. 1911; abst. J. S. C. I. 1911, 30, 1466. F. Kressmann, J. I. E. C. 1915, 7, 920-923; abst. J. S. C. I. 1915, 34, 1221. J. I. E. C. 1914, 6, 625-630; abst. J. S. C. I. 1914, 33, 1914. Junien, Bull. Assoc. Chim. Sucr. 1914, 31, 500-501; abst. J. S. C. I. 1914, 33, 213. E. Hagglund, J. prakt. Chem. 1915, 91, 358-364; abst. J. S. C. I. 1915, 34, 975. 1. Zts. ang. Chem. 1898, 12, 195, 219, 962, 1007; 1903, 16, 572; Pap. Ztg. 1903, 28, 572, 1787; J. C. S. 1896, 70, i, 331; 1899, 76. i, 471; J. S. C. I. 1898, 17, 365, 481; 1898, 17, 1164; Chem. Centr. 1898, 69, I, 808; II, 144, 1140; Zts. ang. Chem. 1903, 16, 572. 2. D. R. P. 92079, 1894; abst. Chem. Centr. 1897, 68, II, 559; Wag. Jahr. 1897, 43, 978. E. P. 10762, 1895; Ber. 1897, 29, 1035; Chem. Centr. 1896, 670; Chem. Ztg. 1896, 20, 887; Pap. Ztg. 1896, 21, 460. Norsk teknisk Tidskrift, 1895,65. SceSwed. P. 28551, 1907. Zts. ang. Chem. 1898, 11, 219; abst. J. S. C. I. 1898, 17, 365, 481. See also Ann. 1819, 12, 172; Dingl. Poly. 1820, 1, 312; 1827, 25, 81; 1854, 134, 219, 316; 1856, 136, 187; 1855,138, 79, 80, 426; 1859, 151, 394; 1866, 181, 233; 1867, 185, 308; 1889, 273, 276; 1893, 287, 91. Wag. Jahr. 1855, 1, 200, 220; 1856, 2, 225, 242; 1859, 5, 40, 401. Zts. f. Spirit. Ind. 1883, (7). Lindsay, Inaug. Dissertation, 1891. 3. See "Cellulose as a Polysaccharide," J. Briggs, J. S. C. I. 1909, 28, 340; abst. C. A. 1909, 3, 1589; Bull. Soc. Chim. 1909, (4), 6, 1028; Rep. Chim. 1909, 9, 370; Chem. Zentr. 1909, 80, II, 270; Chem. Ztg. Rep. 1909, 33, 257, 313; Jahr. Chem. 1909, 62, II, 382; Meyer Jahr. Chem. 1909, 19, 217; Zts. ang. Chem. 1909, 22, 23(H). Lassar-Cohn, Allg. Produktenzeit. 8, 1; Chem. Zentr. 1918. 89, II, 778; C. A. 1919, 13, 3034. CELLULOSE 199 TABLE XVI.—CELLULOSE TO GLUCOSE. APtrmeossspuhreeriens Sulfuric Acid 0.15% 0.3% 0.45% 0.6% 1.3 2.5 2.7 3.1 2.1 6.6 8.6 10.6 2.7 9.3 11.3 12.6 4.0 16.4 30^7 20.3 6.0 2l'5 28.0 43.9 8.0 30.5 38.4 45.0 33.3 9.0 43.1 10.0 35.6 36.6 30.6 18.0 12.0 38.4 14.0 20.0 TABLE XVII.—CELLULOSE TO GLUCOSE (2.7 ATMS. PRESSURE) Hours Percentage of Sugar, with Sulfuric Acid of 864 011.912...3336% 0114315..5633% 01.526.06% 17.4 From the best of his experiments (an exceptional case), he claims to have obtained 45% of sugar and 44% of residue, which residue upon further treatment yielded 27% of sugar, but he docs not appear to have corroborated this experiment by duplicating the work. He was the first to determine the factors which influence the hydrolysis of cellulose, and these are (a) pressure, (b) amount of water present, (c) length of time for maximum sugar formation, and (d) correct acidity. On a semi-manufac turing scale he determined the most favorable conditions to be as follows: The cellulose in the form of fine sawdust is mixed with 0.5% sulfuric acid in the ratio of wood to liquid 1 to 4, and is heated in an autoclave for 15 minutes at a pressure of 9 atmospheres, the sugar being then extracted from the residue. The sugar was not separated as such, but used directly after neutralization for the production of alcohol by fermentation. Yields of alcohol equivalent to 25 gallons of absolute alcohol per ton of dry sawdust are stated to have been obtained. It is usual in the hydrolysis of cellulose with sulfuric acid on the industrial scale, not to recover 200 TECHNOLOGY OF CELLULOSE ESTERS as such the sugar formed, but to ferment it directly into ethyl alcohol, the conditions under which the hydrolysis is carried out, influencing of course, the nature of the sugar formed and the ulti mate yield of alcohol obtained. The results of Simonsen—admittedly the most reliablehave been called in question by Koerner,1 who has pointed out that Simonsen's yields of sugar were determined only by the cupric reducing power of the extracts, which is open to criticism. Furthermore Simonsen's extracts were not completely fermentable. Koerner, working along similar lines, obtained a yield of 12-18% of alcohol from wood cellulose corresponding to (say) 26% of dextrose. From "hydrocellulose" was obtained 18% alcohol, but the source of the hydrocellulose is not stated. Simonsen and Koerner conducted their researches, bearing in mind the utili tarian side of the question, and their work therefore, as has been pointed out by J. Briggs, lacks "the scientific value of a contri bution to the theory of the constitution of the cellulose aggregate." The yield of alcohol theoretically possible from 100 gm. dry cellu lose is 56.9 gm. and as under the most favorable conditions not over 25% of the theoretical quantity has been obtained by the simple hydrolysis of cellulose, it appears probable that of the entire cellulose complex, only a portion is capable of hydrolysis and conversion into fermentable sugar. Braconnot and many of his successors proceeded by employ ing sulfuric acid of such a concentration that its first action in the cold is one of solution due to esterification. A. Stern2 has 1. Ztg. ang. Chem. 1908, 21, 2353; Pap. Ztg. 1908, 33, 3702; C. A. 1909, 3, 484; J. S. C. I. 1908, 27, 1216; Bull. Soc. Chim. 1908, (4), 6, 230; Mon. Sci. 1909, 70, 326; Chem. Zentr. 1908, 79, II, 2049; Chem. Ztg. Rep. 1909, 32, 692; Jahr. Chem. 1905-1908, II, 179; Meyer Jahr. Chem. 1909, 18, 392; Wag. Jahr. 1909, 54, II, 339. See also h. Roth and W. Gentzen, D. R. P. 147844; abst. Zts. ang. Chem. 1903, 16, 244; Chem. Centr. 1904, 75, I, 410; Jahr. Chem. 1904, 57, 878; Chem. Ztg. 1904, 28, 66; Wag. Jahr. 1904, 50, II. 370; Mon. Sci. 1909, 70, 327. See Aktiebolaget Ethyl, U. S. P. 1042332, 1050723, 1912. F. P. 446717, 446718, 1912; abst. J. S. C. I. 1912, 31, 1075; 1913, 32, 133, 192, 377. 2. Proc. Chem. Soc. 1894, 186; J. C. S. 1895, 67, 74; abst. J. S. C. I. 1894, 13, 1230; Bull. Soc. Chim. 1896, (3), 16, 1081; Ber. 1895, 28, R, 462; Jahr. Chem. 1895, 48, 1358; Meyer Jahr. Chem. 1895. 5, 145, 524; Chem. News, 1894, 70, 267; Chem. Centr. 1895, 66, I, 29; Jahr. Chem. 1894, 47, 1132. Proc. ChL-m. Soc. 1904, 20, 43; J. C. S. 1904, 85, 336; abst. Chem. News, 1904, 89, 1 17; J. S. C. I. 1904, 23, 265; Bull. Soc. Chim. 1904, 32, 1175; Chem. Centr. 1904, 75, I, 934, 1405; Chem. Ztg. 1904, 28, 246; Jahr. Chem. 1904, 57, 1161. In this connection see Proc. Chem. Soc. 1904, 20, 90; J. C. S. CELLULOSE 201 pointed out that in this manner the acid-sulfuric esters of a series of dextrin-like bodies are formed which on prolonged boiling in presence of dilute sulfuric acid are gradually hydrolyzed to dextrose. Stern has fractionated these esters and determined the cupric reducing and specific rotatory power of each fraction, the series chemically being analogous to the maltodextrin series of starch products. The "cellulose sulfuric acids" of Stern are non-re ducing bodies, and the yields of barium cellulose sulfates from which all his deductions were made, never accounted for as much as half of the original cotton cellulose operated upon. J. Lindsey and B. Tollens1 isolated 3.5% of crystalline dextrose from wood cellulose by this method, and Ernest2 obtained about 4% of a dextrose syrup from ramie cellulose in the same manner. G. Eckstrom3 records a conversion of 55%-75% of dextrose by heating the cellulose in an autoclave for 0.5-5 hours at a pressure of from 3 to 8 atmospheres. In obtaining alcohol from waste sulfite 1904, 85, 691; abst. Chem. News, 1904, 89, 235; J. S. C. I. 1904, 23, 557; Bull. Soc. Chim. 1904, 32, 1301; Rep. Chim. 1904, 4, 293; Chem. Centr. 1904, 75, I, 1557; Jahr. Chem. 1904, 57, 1161. See also M. Hoenig and S. Schubert, Monats'i. 1885, 6, 708; 1886, 7, 455; abst. Wein. Akad. Ber. 92, (2 Abth.) 737; Bull. Soc. Chim. 1886, (2), 46, 517; Ber. 1885, 18, 614; Jahr. Chem. 1885, 38, 1576. Braconnot, Ann. Chim. Pnys. 1819, (2), 12, 185. Blondeau de Carolles, Ann. 1844, 52, 412; J. prakt. Chem. 1844, 33, 439. Fehling, Ann. 1845, 53, 135; Marchand, J. prakt. Chem. 1845, 35, 200. Bechamp, Ann. 1856, 100, 364. Allihn, J. prakt. Chem. 1880, 130, 61. 1. Ann. 1891, 267, 341; Ber. 1892, 25, 322; 154. Zts. ang. Chem. 1892, 5, 2. Zts. Zuckerind. 1906, 30, 270; abst. J. S. C. I. 1906, 25, 388; J. C. S. 1906, 90, i, 401; Rep. Chim. 1906, 6, 404; Ber. 1906, 39, 1947; Chem. Centr. 1906, 77, I, 1581; Chem. Ztg. 1906, 30, 155; Zts. ang. Chem. 1907, 20, 455; Jahr. Chem. 1905-1908, II, 958. H. Berger and A. Ernest, Ber. 1907, 40, 4671 ; abst. Wag. Jahr. 1907, 53, II, 230. See Stora Kopparbergs Bergslags Aktiebolag, F. P. 402331, 1909; abst. J. S. C. I. 1909, 28, 1221; Wochenbl. Papierfab. 1909, 40, 4265; Pap. Ztg. 1909, 43, 1682. 3. U. S. P. 970029. E. P. 18341, 1907; abst. J. S. C. I. 1908, 27, 514 ; 1910, 29, 1173; C. A. 1908, 2, 1642; Chem. Zentr. 1908, 79, I, 784; Chem. Ztg. Rep. 1908, 32, 42; Wag. Jahr. 1908, 54, II, 326; Zts. ang. Chem. 1908, 21, 1094. F. P. 380358, 1907; abst. J. S. C. I. 1908, 27, 32. Belg. P. 201746, 1907. U. S. P. 1035086, 1042332, 1046160, 1912; 1050723, 1913; 1087356. 1087743, 1087744, 1914; abst. J. S. C. I. 1912, 31, 912, 1075; 1913, 32, 103, 192;1914,33,349. E. P. 6741, 1910; abst. J. S. C. I. 1911, 30, 504. F. P. 402331, 1909; abst. J. S. C. I. 1909, 28, 1221. D. R. P. 193112, 1906; Chem. Zentr. 1908, 79, I, 784; 1909, I, 1296; Chem. Ztg. Rep. 1908, 32, 42; Jahr. Chem. 1905-1908, II, 861; 1909, 62, 344; 1910, 63, II, 419; Wag. Jahr. 1908, 54, II, 326; Ztg. ang. Chem. 1908, 21, 1094. D. R. P. 207354, 1907; Pap. Ztg. 1908, 33, 386; 1909, 34, 1682; 1910, 35, 649, 690, 2519; Chem. Ztg. 1909, 32, 182; 1910, 34, 223; Wochenbl. Papierf. 1910, 41, 638; Pap. Fab. 1910, 8, 238, 582; Svensk kemisk. Tidskrift 1909, Pt. 7; Zts. Chem. Ind. Koll. 1908, 3, 47; C. A. 1909, 3, 2070; Chem. Zentr. 1909, 80, I, 1296; Wag. Jahr. 1909, II, 55, 228; Zts. ang. Chem. 1909, 22, 599. 202 TECHNOLOGY OF CELLULOSE ESTERS lyes, he1 adds a catalyzer to the liquid before fermentation to oxidize the liquor, which is then aerated. H. Ost2 and with W. Wilkening3 first dissolve the cellulose in strong sulfuric acid of 65%-72% strength for a few hours at room temperature to change it into soluble dextrins, which are subse quently converted into dextrose by diluting the mixture with water until it contains 2%-3% H2SO4 and 0.2%-0.5%of cellulose and boiling for 5-8 hours; or for 2 hours in an autoclave at 120°. Whereas they compute that theoretically 100 gm. of water-free cellulose gives 111.1 gm. dextrose; in several instances they actu ally obtained 100 gm. Working along similar lines, only hydrolyzing with dilute sulfuric acid, R. Willstaetter and L. Zechmeister4 obtained 56%-83%. Hydrofluoric acid has been employed in the hydrolysis of proteins5 and cellulose6 (in the form of filter paper), using a lead vessel to carry out the reaction. It was found that HF up to 30% concentration had but little action, but with acid of 40%-50% I. Swcd. P. 34624, 1912; abst. C. A. 1914, 8, 1669. 2. Ber. 1913, 46, 2995; abst. J. C. S. 1913, 104, i, 1148; C. A. 1914, 8, 120; J. S. C. I. 1913, 32, 822, 1062; Bull. Soc. Chem. 1914, (4), 16, 95; Chem. Zentr. 1913, 84, II, 2035; Chem. Ztg. Rep. 1913, 37, 624. For the utilization of sisal waste in the production of alcohol, see Tropical Life, 1917, 13, 155; Bull. Agric. Intell. 1918, 9, 988; J. S. C. I. 1918, 37,677-A. Chem. Ztg. 1912, 36, 1099; abst. J. S. C. I. 1912, 31, 713, 980; Chcm. Ztg. Rep. 1913, 37, 68. Ann. 1913, 398, 313; abst. J. S. C. I. 1913, 32, 784; Bull. Soc. Chim. 1913, (4), 14, 1262. Willstaetter and Zcchmeister, Ber. 1913, 46, 2401; abst. Bull. Soc. Chim. 1913, (4), 14, 1354. Ost and Wilkening, Chem. Ztg. 1910, 34, 461; abst. Chem. Zentr. 1910, 81, I, 2074. 3. Chem. Ztg. 1910, 34, 461 ; abst. C. A. 1910, 4, 1888; J. S. C. I. 1910, 29, 688; J. C. S. 1910, 98, i, 364; Bull. Soc. Chim. 1911, (4), 10, 61; Chem. Zentr. 1910, 81, I, 2074; Jahr. Chem. 1910, 63, II, 420; Meyer Jahr. Chem. 1910, 20, 318; Wag. Jahr. 1910, 56, II, 392; Zts. ang. Chem. 1910, 23, R, 1534. See also, Flechsig, Zts. Physiol. Chem. 1883, 7, 913. 4. Ber. 1913, 46, 2401; abst. C. A. 1913, 7, 3413; J. C. S. 1913, 104, i, 955; J. S. C. I. 1913, 32, 822; Bull. Soc. Chim. 1913, (4), 14, 1354. Hydro chloric acid has been patented for purposes of cellulose hydrolysis as far back as D. R. P. 11836, 1880; abst. Wag. Jahr. 1881, 27, 818. 5. L. HuKouneng and A. Morel, J. pharm. chim. 1908, 99, 486; Compt. rend. 1908, 146, 1291; 147, 212; 1909, 148, 236; Bull. Soc. Chim. 1908, (4), 3, 612, 1146; abst. C. A. 1908, 2, 2397; 1909, 3, 662, 1039; J. S. C. I. 1908, 27, 764; Rev. Chim. 1908, 8, 409; Chem. Zentr. 1908, 79, II, 332; Jahr. Chem. 1905-1908, II, 4498, 4501; Meyer Jahr. Chem. 1908, 18, 236, 239. See also Compt. rend. 1906, 142, 1426. P. Schuetzenberger, Ann. Chim. Phys. 1879, (5), 16, 334. 6. J. Ville and W. Mestrezat, Compt. rend. 1910, 150, 783; abst. C. A. 1910, 4, 2094; J. C. S. 1910, 98, i, 301; J. S. C. I. 1910, 29, 483; Bull. Soc. Chim. 1910, (4), 7, 362, 1064; Rep. Chim. 1910, 10, 281; Chem. Zentr. 1910, 81, I, 1781; Jahr. Chem. 1910, 63, II, 419; Meyer Jahr. Chem. 1910, 20, 253, 318; J. d'Orlowsky, Belg. P. 226890, 1910. CELLULOSE 203 concentration action is more vigorous, and a rapid destruction of the cellulose soon sets in, the mixture assuming a brown color. With 50% acid concentration there is obtained an average of 41 gm. glucose per 100 gm. cellulose, when the process is carried on for 6 hours. They observe on heating glucose with 50% HF that the sugar is gradually destroyed and 53.5% of it disappears when the heating is continued for six hours. This observation may account for the relatively small yield of glucose obtained in the hydrolysis of cellulose as compared with the possible theoretical yield, on the assumption, of course, that the main product of hydrolysis is glucose. A. Ernest1 in hydrojyzing various cellulose materials such as ramie and cellulose from sugar beet, found only dextrose in the hydrolyzed product. On the other hand, on the assumption that all the sugar formed is dextrose, the conversion to alcohol in practice is small, and according to E. Hagglund,2 considerable amounts of pentoses may be found in the final product. A. Claessen3 has made an exhaustive technical study of this 1. Zts. Zuckcrind. 1906, 30, 270; abst. J. S. C. I. 1900, 25, 388; J. C. S. 1906, 90, i, 401; Rep. Chim. 1909, 6, 404; Ber. 1906, 39, 1947; Chem. Centr. 1906, 77, I, 1581 ; Ztg. ang. Chem. 1907, 20, 455. See also A. Ernest and H. Berger, Ber. 1907, 40, 4671; abst. Wag. Jahr. 1907, 53, II, 230. 2. J. prakt. Chem. 1915, 91, 358; abst. C. A. 1915, 9, 3127; J. C. S. 1915, 108, i, 629; J. S. C. I. 1915, 34, 883; Biol. Chem. Zts. 1915, 69, 181. 3. U. S. P. 700616, 1902; abst. J. S. C. I. 1902, 21, 867; Mon. Sei. 1902, 58, 190. U. S. P. 825808, 1906; abst. J. S. C. I. 1906, 25, 771; Chem. Zts. 1906, 5, 495; C. A. 1907, 1, 1 16; Mon. Sci. 1907, 67, 55. U. S. P. 696800. 1902; Re. 12108, 1903; abst. J. C. S. I. 1902, 21, 630; 1903, 22, 706; Mon. Sci. 1902, 58, 190. U. S. P. 654518, 1900; Re. 12069, 1902; abst. J. S. C. I. 1903, 22, 153; Chem. Ztg. 1900, 24, 693; Mon. Sci. 1902, 58, 13. U. S. P. 695795, 1902; abst. J. S. C. I. 1901, 20, 734; 1902, 21, 630; Mon. .Sci. 1902, 58, 190. U. S. P. 707903, 1902; abst. J. S. C. I. 1902, 21, 1190; Mon. Sci. 1903, 59, 111. U. S. P. 1101061, 1914; abst. J. S. C. I. 1914,33, 761. E. P. 258,259, 1900; abst. J. S. C. I. 1900, 19, 364, 1028. E. P. 4199, 1901, 20, 734. E. P. 12588, 1901; abst. J. S. C. I. 1910910,1 2; 0a,bst1.00J8.. S. EC.. PI.. 22709, 1905; abst. J. S. C. I. 1906, 25, 898. F. P. 365595, 1906; abst. C. A. 1907, 1, 2429; J. S. C. I. 1900, 25, 1000; Mon. Sci. 1907, 67, 99. F. P. 295847; abst. J. S. C. I. 1901, 20, 1008; 1902, 21, 358; Mon. Sci. 1901, 57, 41. F. P. 448496, 1912; abst. J. S. C. I. 1913, 32, 441. D. R. P. 111868, 1899; abst. Wag. Jahr. 1900, II, 288; Chem. Centr. 1900, II, 6O8; Chem. Ztg. 1900, 24, 524; Zts. ang. Chem. 1900, 13, 651 ; Jahr. Chem. 19(H), 53, 809. D. R. P. 118540, 1900; Wag. Jahr. 1901, II, 280; Chem. Ztg. 1901, 25, 252; Zts. ang. Chem. 1901, 14, 348; Jahr. Chem. 1901, 54, 844. D. R. P. 118542, 1900; Wag. Jahr. 1901, II, 281; Chem. Centr. 1901,1, 716; Chem. Ztg. 1901,25,249; Zts. ang. Chem. 1901, 14, 348. D. R. P. 118543, 19(H); Wag. Jahr. 1901, II, 282; Chem. Centr. 190C I, 716; Chem. Ztg. 1901, 25, 249; Zts. ang. Chem. 1901,14,349. D. R. P. 118544, 1900; Wag. Jahr. 1901, II, 282; Chem. Centr. 1901, 72, I, 716; Chem. Ztg. 1901, 25, 249; Zts. ang. Chem. 1901, 14, 349; Jahr. Chem. 1901, 54, 844. D. R. P. 121869, 1900; Wag. Jahr. 1901, U, 282; Chem. Ztg. 1901, 25, 571; 204 TECHNOLOGY OP CELLULOSE ESTERS problem, employing, in general, sulfur dioxide in the gaseous or liquid state as the hydrolyzing material. He uses also a mixture of 0.2% H2SO4 with 20% SO2 dissolved in water. The reaction is carried out in a current of air and the material heated to a temp erature of 120°- 145 "for one hour at a pressure of 6-7 atmospheres. When this process was attempted on an industrial scale many were the difficulties which were encountered, but it is of particular interest since it was the beginning of this industry in the United States for the production of ethyl alcohol from wood. In 1903 the United States patent rights for the Claessen process were acquired by a firm in Chicago, Illinois, and after experimentally demonstrating this process to its satisfaction, erected a plant at Hattiesburg, Miss, at a cost of about $250,000 to operate on long-leaf pine saw mill waste. This plant was substantially a failure because of the number of mechanical and technical diffi culties, the chief of which were as follows:1 (a) the length of time necessary to hydrolyze the wood was found to be 4-6 hours; (b) the large quantity of acid needed; (c) the action of the acid and water in the rotating digester reduced the wood to a very fine powder, and formed much sulfuric acid which acted upon the sugar and other substances present to form gums and caramels, and so made the complete extraction of the sugar from the residue both unduly tedious and expensive; (d) the digester was lead lined, and the buckling and breaking of the lining necessitated repairs after every two or three "cooks," which proved a great source of delay and expense. A. Claessen2 found technical difficulties in dealing with cellulose materials containing tannic and gallic acids, such as oak, chestnut, and in a lesser degree the poplar and beech. Gallic acid appears to be always formed on hydrolysis of these woods, which materially interferes during the subsequent fermentation of the sugars. The trouble was finally overcome by the addition Zts. ang. Chem. 1901, 14, 788. D. R. P. 123911, 1900; Wag. Jahr. 1901, II, 283; Chem. Centr. 1901, 72, II, 1032; Chem. Ztg. 1901, 25, 940; Zts. ang. Chem. 1901, 14, 1144. D. R. P. 161644; abst. J. S. C. I. 1905, 24, 1078; Wag. Jahr. 1905, II, 338; Chem. Centr. 1905, 76, II, 660; Chem. Ztg. 1905, 29, 772; Zts. ang. Chem. 1905. 18, 1567. Zts. Vcrein Zuekerind, 1900, 589; 1901, 348, 351, 754; 1907, 57, 206, 525; abst. Meyer Jahr. Chem. 1907, 17, 375, 376. Can. P. 77979, 81207, 84014. Belg. P. 139919, 1898; 142335, 1899. 1. Chem. Trade J. & Chem. Engr. 1918, 63, 231. 2. U. S. P. 825808, 1906; abst. J. S. C. I. 1906, 25, 771; C. A. 1907, 1, 16; Mon. Sci. 1907, 67, 55. CELLULOSE 205 of a ferric salt to the liquid after hydrolysis. In the French modification of the Claessen process,1 the by-products are said to have value as a cattle food. M. Ewen and G. Tomlinson2 who were associated with the Claessen process, began experimenting along new lines in order to remedy the defects of the Hattiesburg plant. Instead of using an aqueous solution of sulfur dioxide, they passed the gas into the digester along with steam, which furnished therefore, both the heat and moisture required. Somewhat later however, Ewen and Tomlinson abandoned the use of SO2 and were granted a patent3 covering the use of sulfuric acid as the catalytic agent. . This patent and the process patented by E. Simonson4 disclose a 1. F. P. 365595, 1906, abst. C. A. 1907, 1, 2429; J. S. C. I. 1906, 25, 1000; Mon. Sci. 1909, 67, 99. 2. U. S. P. 763472, 1904 ; abst. J. S. C. I. 1904, 23, 797. Belg. P. 220462, , 1909. F. P. 343006, 1904. abst. J. S. C. I. 1904, 23, 30073, 1912; abst. J. S. C. I. 1914, 33, 132, 156. U. S.7P9.7,1909342.440Et.oP1.0320405702, 1912; abst. J. S. C. I. 1912, 31, 832, 833. U. S. P. 938308, 1909; abst. Chem. Ztg. Rep. 1909, 659; Zts. ang. Chem. 1909, 22, 2462; Pap. Ztg. 1910, 35, 262; J. S. C. I. 1910, 29, 38; C. A. 1910, 4, 381. U. S. P. 1032391, 1032392, 1912; abst. J. S. C. I. 1912, 31, 762, 832; C. A. 1912, 6, 2863. F. P. 408229, 1909 ; abst. J. S. C. I. 1910, 29, 586. G. Tomlinson, "Wood Waste as a Source of Ethyl Alcohol," Chem. and Met. Eng. 1918, 19, 552; J. S. C. I. 1918, 37, 71 1-A ; 274-R. Orljavacer Chemische Fabrik, F. P. 357432, 1905; abst. J. S. C. I. 1906, 25, 117. J. d'Orlowski, F. P. 405187, 1909; abst. J. S. C. I. 1910, 29, 230. F. P. 343006, 1904 ; abst. J. S. C. I. 1 904, 23, 994. E. P. 10664, 1904 ; abst. J. S. C. I. 1905, 24, 808. R. McKee, U. S. P. 1273392, 1284739, 1284740; 1918; abst. J. S. C. I. 1918, 37, 600-A; 1919, 38, 71-A. E. P. 120520, 1918; abst. J. S. C. I. 1918, 37, 780-A. Paper, 1919, 24, 584; abst. C. A. 1919, 13, 1927. E. P. 24589, 1909; abst. J. S. C. I. 1910, 29, 710. G. Foth (Chem. Ztg. 1913, 37, 1145, 1221, 1297; Zts. Spirit. Ind. 1913, 36, 161, 485, 497, 595; Deut. Essigind. 17, 481; abst.'C. A. 1914, 8, 1343; Chem. Zentr. 1913, 84, II, 1831; Wag. Jahr. 1913, 59, II, 431; Zts. ang. Chem. 1913, 26, I, 519; II, 432), found 0.5% by weight of fusel oil in alcohol by this process, with only traces of methyl alcohol and no acetone. For the preparation of xylose from corn cobs, see C. Hudson and T. Harding, J. Am. Chem. Soc. 1917, 39, 1038; 1918, 40, 1601; abst. J. S. C. I. 1917, 36, 730; 1918, 37, 778-A. B. L'aForge and C. Hudson, J. Ind. Eng. Chem. 1918, 10, 925; J. S. C. I. 1919, 38, 86-A. K. Munroe, J. Am. Chem. Soc. 1919, 41, 1002; abst. J. S. C. I. 1919, 38, 550-A; C. A. 1919, 13, 2036. For production of alcohol from peat, refer to G. Pradel, E. P. 5128, 1907; J. S. C. I. 1908, 27, 416. 3. U. S. P. 938308, 1909; abst. J. S. C. I. 1910, 29, 38; Mon. Sci. 1910, 73, 87. F. P. 408299, 1909; abst. J. S. C. I. 1910, 29, 586. Can. P. 146794, 1913; abst. C. A. 1913, 7, 2137. 4. D. R. P. 92079, 1894; abst. Chem. Centr. 1897, 68, II, 559; Wag. Jahr. 1897, 43, 543, 978. In the T. Wagner process (U. S. P. 1261328, 1918; abst. J. S. C. I. 1918, 37, 410-A,) the fermented sugar-containing liquor resulting from the hydrolysis of ccllulosic material is concentrated, after the distillation of the alcohol, the concentrated product containing more than 30% of reducing sugars (calculated as dextrose) and approximately 25%-35% of water. See R. Ruttan, J. S. C. I. 1909, 28, 1290; abst. C. A. 1910, 4, 637; Chem. Zentr. 1910, 81, I, 1393; Zts. ang. Chem. 1910, 23, 860; Jahr. Chem. 1909, 206 TECHNOLOGY OF CELLULOSE ESTERS remarkable identity as to ideas. They erected a plant at George town, South Carolina for the demonstration of their process, which plant was later acquired by a powder company, and has been intermittently operated up to the present time.1 On an industrial scale, cellulose in the form of sawdust may be converted first to sugar and finally to alcohol in the following manner. Sawdust from several sawmills is brought by the aid 62, 99; Wag. Jahr. 1909, 55, II, 368; Chetn. Ztg. Rep. 1909, 33, 59. Comp. Industrielle des Alcools de l'Ardeche, F. P. 391057, 1908; E. P. 26619, 1908; abst. J. S. C. 1. 1908,27, 1126; 1909, 28, 998. F. P. 358696, 1905; abst. J. S. C. I. 1906, 25, 277. F. Gallagher and I. Pearl, Eighth Intl. Cong. Appl. Chem. 1912, 13, 147; J. S. C. I. 1912, 31, 870. H. Fenton, J. S. C. I. 1901, 20, 757. J. Teeple, J. Ind. Eng. Chem. 1913, 5, 680; abst. C. A. 1914, 8, 1665. R. Hauers and B. Tollens, Ber. 1903, 36, 3306; abst. Chem. Centr. 1903, 84, II, 1167; J. C. S. 1904, 86, i, 16; J. S. C. I. 1903, 22, 1151; Bull. Soc. Chim. 1904, (3), 32, 1104; Jahr. Chem. 1903, 56, 1011. R. Hauers, Dissertation, Gottingen 1902. J. Koenig, D. R. P. 265483; abst. Chem. Zentr. 1913, 84, II, 1535; Chem. Ztg. Rep. 1913, 37, 587; Wag. Jahr. 1913, 59, II, 348; Zts. ang. Chem. 1913, 26, 653. E. P. 8006, 1914; abst. J. S. C. I. 1915, 34, 901; C. A. 1916, 10, 75. V. Omelianski (Compt. rend. 1897,125, 1131; Arch. des Sc. biolog. 1900, 7, 411; Chem. Centr. 1900, 71, I, 918) in studying the prod ucts of the fermentation of cellulose, fermented pure paper in the presence of calcium carbonate at a temperature of about 35° for 13 months. The prod ucts obtained from 3.473 gm. of paper were: acetic series of acids, 2.24 gm.; CO2, 972 gm.; and hydrogen, 0.014 gm. The acids were chiefly acetic and butyric, with small quantities of valeric. Higher alcohols and odoriferous products were also formed but not isolated. No methane was detected. 1. Several years ago western capital erected a plant at Port Hadlock, Washington, on Puget Sound, for the production of ethyl alcohol and cattle food from sawdust obtained from mills at Seattle, Tacoma, Everett, Anacortes, and Port Blakeley. The plant was equipped with 6 digesters of the same size and type as those that were developed in France by the Compagnie Indus trielle des Alcohols de l'Ardeche. These digesters consist of steel cylinders, 21/2 m. in internal diam. by 21/s m. in length, through which are placed 22 tubes, 160 mm. in diam. The outside of each of a tube head has a flanged boiler steel jacket, one to receive the live steam from the boiler and the other to take off the condensed steam, the heating being indirect, the idea being to save steam by means of the indirect heating. Sawdust and enough water are added through a manhole into the space between the tubes to raise the moisture content to about 45%. Anhydrous sulfur dioxide was then added, and the mixture was cooked at 75-100 lbs. pressure. The cost of conversion was excessive because of the very rapid corrosion of the digesters, the long time necessary to heat indirectly, and because the sulfurous acid gas leaked from the digester into the stream space, thereby preventing the use of the low pressure steam. In addition, the extraction equipment was inefficient and out of date, though the buildings of the plant were excellent and expen sive, and much of the equipment was imported from France at a large cost. The extracted sawdust—which had only from 50%-60% of the sugar formed extracted from it—was mixed with Hawaiian molasses, and was put on the market as a cattle food. It was necessary to dry the extracted material down to about 12% moisture in order to prevent decay, and this caused trouble because of explosions of dust in the driers. In addition, the plant was situa ted about 80 miles from a railway, which greatly increased transportation charges. These facts coupled with the very poor design and equipment— CELLULOSE 207 of belts to a central factory, and is there distributed between several digesters in which the acid hydrolysis is to be carried out. These digesters are of a spherical shape 12 feet in diameter, with steel plate construction and lined with a special acid-resisting brick. After the digester has been charged with sawdust, sul furic acid is added until the acid constitutes about 0.5% to 1% on the wood, calculating on the dry weight. The vessel is then especially digester and extraction equipment—were no doubt the prime reasons which caused the failure of this plant. The alcohol company subsequently disposed of the Georgetown plant, and the company was reorganized, a considerable amount of foreign capital being introduced. A large plant for the production of 5,000 gallons of ethyl alcohol per day was erected at Fullcrton. At this plant from 2o%-28% of the anhydrous wood is rendered soluble, and of this amount 80% can be converted into fermentable sugar, though to accomplish this requires most careful control. It is likely that a greater percentage will be obtained by the use of dilute acids. For the present, therefore, a conversion yielding 20%-22% of fermentable sugars, or from 10%- 1 1 % of ethyl alcohol corresponding to a max imum of, say, 35 gallons of 95% alcohol per dry ton, represents the immediate goal. On a large scale the actual average yields have hardly exceeded half of this amount, so that there is a wide margin for improvement. An excellent description of the process and of the plant employed is • given in a paper on "By-Products of the Lumber Industry," issued by the U. S. Dept. of Commerce, from which the following details are taken. The sawdust is conveyed on a belt from several sawmills to the alcohol plant, and lifted into storage bins by means of an elevator. From the storage bin it is distributed to four digestors as required for charging. These digesters are of spherical shape, 12 ft. in diam. They are of steel-plate construction and are lined with acid proof brick. After a digester is charged with sawdust, diluted sulfuric acid is added until it constitutes about 0.5%-l% of the weight of the dried wood. The digestion is then slowly rotated by means of a worm gear by direct steam. The pressure gradually rises to 120 lbs. and a maximum temperature of 335° F. is reached. The total time of digestion, including charging, heating up, cooking, blow-off, and discharge, is about one hour. After complete digestion the digester is discharged, and the wood, now known as "hydrolyzcd" wood, is carried by belt conveyors to the diffusion batteries, in which the soluble constituents of the mass are extracted with hot water, in the same manner as in tannin-extract manufacture and in sugar extraction. The product of the digester contains more water than the raw material—which often contains 50% water—owing to the addition of the dilute sulfuric acid and to the condensation of steam used for the heating. After extraction the washed residue, consisting of unchanged sawdust, is conveyed to compressors, where the water contained is reduced to about 55%. It is afterwards burnt as fuel, and is sufficient for the generation of all the steam and power required in the plant. The liquor from the diffusion battery, known as wood liquor, contains sulfuric acid, sugar, and other organic compounds, and is next hydrolyzcd with milk of lime in tanks fitted with agitators. It then flows into a storage tank. It is further clarified by decantation, and after cooling is pumped into the fermenting vats. Yeast grown in wood liquor is added, after which fermen tation proceeds. The fermented liquor is then distilled in stills for the pro duction of rectified alcohol. The alcohol thus produced is of a high grade, and is reported to contain only traces of fusel oil, esters, and ethers. When properly purified, it differs in no respect from the ordinary grain alcohol. 208 TECHNOLOGY OP CELLULOSE ESTERS slowly rotated by means of a worm-gear while steam is used for heating, the maximum temperature reached being 120°. The time of charging, heating up, cooking, blowing off and discharing is about one hour. After the hydrolysis, the acid liquor con taining the sugar, is passed through diffusion batteries in order to • remove unchanged wood and to separate the soluble portion. The insoluble residue of practically unchanged sawdust is conveyed to hydraulic presses where its water content is reduced to 55% by pressure alone. The mother liquor from the diffusion batteries is neutralized with lime in tanks fitted with stirrers, it is further clarified by decantation and after cooling is pumped into fer mentation vessels. Yeast which has grown in wood liquor is added, and the fermentation allowed to proceed. The fermented liquor is finally distilled in column-stills for the production of concentrated alcohol. A. de Posnansky and L. Spassky1 first purify their cellulose material before attempting hydrolysis, and extract the material with dilute alkaline solution to remove resins and tannins. Next, in order to remove lignin, they heat with a dilute solution of calcium bisulfite for two hours and follow this by an acid treatment. The purified material is hydrolyzed with a dilute solution of hydrochloric, sulfuric or hydrofluoric acids, saccharification At the Fullerton plant it was estimated in 1913 that if a monthly capacity of 100,000 gallons had been reached, the cost would not have exceeded 21 cents per gallon, as against 30 cents, the cost of grain alcohol at American distil leries in 1913. But since the summer of 1916 the plant has been running continuously, taking advantage of the high prices ruling. The quality of the product at Fullerton was reported upon as one of the purest cologne spirits that had come under the observation of the analyst. If the cost of production should be higher than in 1913, then the fact that alcohol from either grain or molasses is more than double the price of that year, would still leave the advantage in favor of the product from wood waste. As the sugars used in wood alcohol can be used for feeding animals, as is done with cane molasses, there would seem to be great possibilities here. In the same paper a short account is also given of the manufacture of alcohol from sulfite liquor, in which similar reactions take place as those already described. This process has been introduced on a large scale in Sweden, ami at three paper mills in that country about a million and a quarter gallons of alcohol arc obtained per annum from sulfite liquor, and the process is also being worked in the United States. 1. L. Spassky, F. P. 451268, 1913; abst. J. S. C. I. 1913, 32, 620; C. A. 1913, 7, 3187; Mon. Sci. 1914, 81, 42. A. de Posnansky and L. Spassky, F. P. 459593, 1912; abst. J. S. C. I. 1913, 32, 1167; C. A. 1914, 8, 2637. Swiss P. 61410, 1912; 63563, 1913; abst. C. A. 1914,8,2276. A. de Posnansky, F. P. 464502, 468188; 473925, 1913; abst. J. S. C. I. 1914, 33, 497, 978; 1915, 34, 729; C. A. 1914, 8, 3215. CELLULOSE 209 being complete after three hours. The alkaline and bisulfite treatments as well as the acid hydrolysis are all carried out at 140°. The volatile acids present are removed by distillation under reduced pressure, the residual sugar solution being finally neu tralized and extracted with alcohol. F. Gallagher1 in hydrolyzing sawdust distils off any vola tile products present such as turpentine, in the first stages of the heating. He also allows the volatile products formed during the hydrolysis to escape continuously, or intermittently, while main taining the pressure. He claims to obtain by this procedure a greater yield of sugar and a liquid more suitable for the fermen tation process. The bisulfite treatment referred to above for removal of lignin and other compounds, gives a liquor containing small quantities of sugar. In the preparation of wood pulp for paper manufacture, an enormous quantity of these waste sulfite liquors are formed and many schemes have been suggested for their utilization.2 A preliminary treatment of crude cellulose materials by means of chlorine has been suggested.3 The cellulose, without washing, is digested with 1% of its weight of sulfuric acid for 30 minutes under a pressure of 9 kilograms. It has also been sug gested in the case of straw4 to heat under pressure with water. The solution obtained is employed for the extraction of a second quantity of straw. Each portion is extracted twice under pres- 1. U. S. P. 1056161, 1913; 1091327, 1914; abst. J. S. C. I. 1913, 32, 441; 1914, 33, 497. F. Gallagher and H. Mork, U. S. P. 1037185, 1056162, 1056163, 1913. E. P. 400, 14939, 1913; abst. J. S. C. I. 1913, 33, 441, 1166; 1914,33,801; C. A. 1912, 6, 3340. F. Gallagher and H. Mork, U. S. P. 1033064, 1912; abst. J. S. C. I. 1912, 31, 833. E. Gazagne and R. Demuth, F. P. 477077, 1914; abst. J. S. C. I. 1916, 35, 613. 2. H. Landmark, Chetn. Ztg. 1915, 39, 98; abst. J. S. C. I. 1915, 34, 275. A. Frohberg, Wochenbl. Papier-Fabr. 1913, 44, 4432; abst. J. S. C. I. 1913, 32, 1152. J. Koenig, J. Hasenbaeumer and M. Braun, Zts. ang. Chem. 1913, 26, 481 ; abst. J. S. C. I. 1913, 32, 939. Holzverkohlungs Indus trie A. G. Belg. P. 254945, 256353, 1913. 3. Standard Alcohol Co. U. S. P. 1032443, 1032444, 1032449, 1032450, 1033064, 1912; 1056162, 1913; 1096030, 1914; abst. Mon. Sci. 1914, 81, 139. F. P. 452920,452921, 453129, 460085, 1913; abst. J. S. C. I. 1912, 31, 833; 1913, 32, 441, 761, 833; 1914, 33, 37; C. A. 1914, 8, 3215. D. R. P. 279991, 1913; abst. C. A. 1915,9,2124. Aust. P. 71273, 1916; abst. C. A. 1916, 10, 2497. Swed. P. 41072, 1916; abst. C. A. 1916, 10, 2612. Norw. P. 27188, 1916; abst. C. A. 1916, 10, 3172. 4. W. Giles and F. Norris, U. S. P. 918997, 1909; abst. J. S. C. I. 1909, 28, 538; C. A. 1909, 2, 1795; Mon. Sci. 1909, 71, 142. 210 TECHNOLOGY OF CELLULOSE ESTERS sure, first with a solution from a previous extraction, and secondly with water. The united solutions are acidified, and when saccharification is complete, are neutralized and fermented. An important advance was made by R. Willstaetter and L. Zechmeister1 in 1913. They found that fuming hydrochloric acid of a specific gravity of 1.209-1.212 at 15°C., (containing 41% concentration of acid) was capable of hydrolyzing cellulose in the cold. One part of cellulose in the form of cotton was added to seven parts of concentrated hydrochloric acid. In a very short period the cotton had dissolved. When water was added to the solution after it had stood for a short period, the cellulose was precipitated quantitatively. If however, the concentrated solu tion of the cellulose be allowed to stand for two days and then diluted, no cellulose is precipitated, but instead an optically active solution is obtained. The solution, moreover, has strong reducing properties when tested with Fehling's solution. It is claimed dextrose is formed to the extent of 95%-96% of the possible theoretical conversion. The concentrated hydrochloric acid solution containing the dissolved cellulose is optically inactive at first, but after an hour, a slight rotation is observable. The rotatory power then gradually increases and becomes constant at the end of 24-48 hours, the actual number of hours depending on the concentration of the hydrochloric acid. The rotation figure does not increase regularly from zero to its maximum, but rises for the first few hours, then remains practically constant for a short period and finally increases again until the maximum is reached. These changes are interpreted on the assumption that an intermediate compound is formed at an early stage during the hydrolysis. According to these workers, cellulose in other forms such as filter paper, or pine wood, may also be hydrolyzed by very concen trated hydrochloric acid (specific gravity 1.2). In the case of pine wood a 30% residue of lignin substances is obtained. Con centrated hydriodic acid is less reactive, and with the latter heating is necessary in order to dissolve the cellulose. Hydrobromic acid (specific gravity 1.78), concentration (66%), behaves 1. Ber. 1913, 46, 2401; abst. J. S. C. I. 1913, 32, 822; J. C. S. 1913, 104, i, 955; C. A. 1913, 7, 3413; Bull. Soc. Chim. 1913, (4), 14, 1354; Chem. Zentr. 1913, 84, II, 1209. CELLULOSE 211 in a manner similar to hydrochloric acid (41%), the hydrobromic acid dissolving the cellulose even at 0°. With hydrofluoric acid of 70%-75% strength a similar action takes place. In view of R. Willstaetter and L. Zechmeister's work con cerning the action of concentrated hydrochloric acid on cellu lose in the cold, it is of interest to refer to H. Fenton's experi ments1 in which he treats cellulose (Swedish filter paper—50 gm.) with dry hydrogen chloride dissolved in an inert solvent (carbon tetrachloride). He obtains 3.1 gm. of chloromethylfurfural and 1.57 gm. of dextrose. According to Fen ton the two latter compounds are probably produced in equa-molccular pro portions initially, but part of the dextrose formed is destroyed during the heating. Similar reactions take place with hydrogen bromide. The formation of these halogen derivatives point to the presence of a ketohexose nucleus or grouping in the cellulose complex. R. Willstaetter and L. Zechmeister, in their hydrolysis with concentrated hydrochloric acid, identified their products solely by means of optical activity determinations and copper reduction figures. They did not, however, prove the quantitative yield to dextrose by actual isolation of the dextrose or a derivative of the sugar. H. Ost,2 regards their results, especially with the higher concentrations of cellulose, as improbable. According to M. Cunningham3 the products of hydrolysis of cellulose are not iden tified by the rotation constants of the hydrolyzed solution, and in support of this view adduces the following reasons. Widely different types of cellulose such as cotton and esparto-cellulose give identical optical rotation data on hydrolysis, but the ultimate products necessarily have divergent constituents. In addition, it is known that concentrated hydrochloric acid produces con stitutional changes even in the simple hexoscs—large fluctuations in optical activity accompanying slight variation in the strength 1. Proc. Chem. Soc. 1901, 17, 166; abst. J. S. C. I. 1901, 20, 757; Chem. News, 1901, 84, 7; Rep. Chim. 1901, 1, 515; Chem. Centr. 1901, 72, II, 405; Chem. Ztg. 1901, 25, .r>!)l ; Jahr. Chem. 1901, 54, 840. 2. Ber. 1913, 46, 2995; abst. J. C. S. 1913, 104, i, 1148; C. A. 1914, 8, 120; J. S. C. I. 1913, 32, 1062; Bull. Soc. Chim. 1914, (4), 16, 95; Chem. Zentr. 1913, 84, II, 2035; Chem. Ztg. Rep. 1913, 37, 624. Chem. Ztg. 1912, 36, 1099; abst. J. S. C. I. 1912, 31, 713, 980; Ann. 1913, 398, 313; J. S. C. I. 1913, 32, 784. 3. J. C. S. 1918, 113, 173; abst. C. A. 1918, 12, 1379; J. S. C. I. 1918, 37, 236-A; Ann. Rep. Soc. Chem. Ind. 1918, 3, 127, 149. 212 TECHNOLOGY OF CELLULOSE ESTERS of acid. Cellulose under the action of concentrated hydrochloric acid forms esters of polysaccharoses containing acidic hydroxyl groups. Cunningham failed to isolate dextrose F. Gallagher and I. Pearl1 have made a fsreormiestheofsoeluxtpieorni. ments on the hydrolysis of sawdust from long-leaf pine wood screened through a 10-mesh sieve. The proportion of sulfuric acid used was 1 per cent. of the dry weight of wood, the proportion of liquor was 3: 1, the maximum pressure was 135 lb. per sq. in., maintained for 30 minutes, and the total duration of the treatment was about 70 minutes. The digested material was extracted with water, evaporated to a density of 1.045 and fermented. Subsequent hydrolysis of the residue gave a further yield of fer mentable sugars. The following table illustrates some of the results obtained: TABLE VII —HYDROLYSIS OF PINE WOOD Fer mentable Sugars Ratio of Ferment able Sugars to total Extract BeCfeolrleulAofsteer Diges- Diges tion tion Material Total Ex tract Re ducing Ma terial Per Per Per Per Per Per ab.. LReosnigduleeaffrpoimne(sa)awdust. . . c2e2n.t0. c1e9n.t3. c1e1n.t8. c0e.n5t3. c5e4n.t0. c5e2n.t0. 6.3 4.7 3.0 0.47 52.0 42.0 2.8 1.7 1.6 0.57, . d. Bleached cotton 3.1 1.6 1.4 0.44 gf.. BRleesaicdhuedfsroodma (wf)ood pulp. 17.7 16.0 6.3 0.3565 4.5 2.8 2.5 7.5 4.3 3.8 0 51 Other investigators who have contributed to this subject include Mitscherlich,2 Neumann,3 Voerkelius,4 G. Foth,5 R. v. 1. Eighth Intl. Cong. Appl. Chem. 1912, 13, 147; abst. J. S. C. I. 1912, 31, 870, C. A. 1912, 6, 3013. 2. D. R.P. 72161; abst. Mon. Sci. 1905, 63, 823; Ber. 1894, 27, 149; Wag. Jahr. 1893, 39, 1063; Zts. ang. Chem. 1893, 6, 732. U. S. P. 284319, 1883. 3. "Critical Study of the Hydrolysis of Cellulose from Wood." Diss. Dresden, 1910. 4. Wochenbl. Papierfabr. 1911, 42, 854; abst. C. A. 1911, 5, 2942; Chem. Ztg. Rep. 1911, 35, 852. 5. Chem. Ztg. 1913, 37, 1145, 1221, 1297; abst. C. A. 1914, 8, 1343; Chem. Zentr. 1913, 84, II, 1831; Wag. Jahr. 1913. 59, II, 431; Zts. ang. Chem. 1913, 26, I, 519; II, 432; Zts. Spirit. Iud. 1913, 36, 161, 485, 497, 595; Deut. Essigind. 17, 481. CELLULOSE 213 Demuth,1 C. Schwalbe and W. Schulz,2 Societe anonyme "Origo",3 H. Wallin,4 W. Cohoe,5 T. Koerner,6 F. Zimmer,7 H. Ruediger,8 W. Gentzen and L. Roth,9 and G. Zemplen.10 Patent protection for carrying these ideas into effect, have been granted to E. Bouchard- Praceiq, 11 A. Boernen,12 H. Bergstrom, 18 E. Tillberg,14 and others.15