Fermentation sulfite waste liquor

Because wood sugar solutions are sterile, they permit yeast to survive under conditions that are suitable for reuse of the yeast. This procedure is similar to that used in the fermentation of sulfite liquor at the Mechan-icsville. New York, plant as early as 1913 and in Swedish and German processes since that time. Yeast reuse has also been employed for sulfite waste liquor in Canada. ... 

The application of these organisms decreases the BOD (biological oxygen demand) of such solutions because of the utilization of the pentoses. When sulfite waste liquor is fermented in this manner, the BOD is reduced 34.3%. Scholler reports yields of mixtures of butyl alcohol, acetone, ethyl alcohol and fatty acids equivalent to 13 to 16%... 

In the growing of food yeast on wood sugar, one of the most difficult problems is that of foaming. This difficulty has been largely overcome by a fermenter designed for use in the production of yeast from sulfite waste liquor in the Waldhof plant at Mannheim. A modification of the fermenter was used for the continuous production of yeast on wood sugars in America. Fermentation periods of 2.6 to 3 hours were obtained with a strain of Torula utilis. Yields were 38 to 49% of the total sugar. 

Similar development has occurred in Germany.In 1943 it was reported that 250,000 hectoliters of alcohol were produced from sulfite waste liquor. The preferred method of fermentation was a continuous method in which the yeast was grown on chips or twigs and the neutralized sulfite waste liquor flowed through these chips. ... 

A plant for the fermentation of sulfite waste liquor in America was built at Mechanicsville, New York, by the West Virginia Pulp and Paper Company in 1914. The alcohol stills and some of the other equipment were imported from Germany and were considered the most modern at that time. In comparison to present American stills, these were very inefficient because they were wasteful of steam and did not recover all the alcohol. This plant reused the yeast from a previous fermentation for succeeding fermentations. The plant produced about 221,000 gallons of alcohol per year in 1919. In later years, because of the inefficiency of the alcohol stills with dilute alcohol solutions, molasses was added to the sulfite waste liquor to increase the alcohol content. The plant operated until 1939, when it was closed because of obsolescence. 

Fermentation of Sulfite Waste Liquor. The sulfurous acid used in the sulfite pulping liquor causes hydrolysis of the more easily hydrolyzable components of wood, especially the pentosans in the hemicellulose. About 35 percent of the potentially fermentable sugars in the wood are hydrolyzed. However,... 

Leonard, R.H., Peterson, W.H., Johnson, M.J. (1948) Lactic acid from fermentation of sulfite waste liquor. Ind. Eng. Chem. 40, 51-61. Leopold, A.C., van Schaik, R, Neal, M. (1960) Molecular structure and herbicide adsorption. Weeds 8, 48. 

Lactic acid can be produced by chemical processes, or by fermentation. There are several possible routes for the production by chemical processes. Today more than half of the total consumption is produced by fermentation in which several carbohydrate sources such as whey, barley, sugarcane, soybean, milk, corn, sulfite waste liquor and potatoes can be used as substrate. Careful selection of the fermentation bacteria Lactobacillus, Leuconostos, Lactococcus, Pediococcus, Carno-bacterium Listeria, Staphylococcus and Bacillus) allows producing the desired isomers, the L, the D or both. Industrially used specie is Lactobacillus Delbrueckii with glucose or sucrose as substrate. 

Ethanol also can be produced by fermentation of starch, whey, and sulfite waste liquor. Grain fermentations require additional pretreatment... 

The fermentation of sulfite waste liquor was attacked in a novel way by Nord and co-workers and is reported by Nord and Mull (93). Fusarium Uni Bolley ferments pentoses and was able to grow on sulfite liquor provided the liquor was first freed of toxic substances by lime treatment or, alternatively, by a resin. The amount of alcohol produced was small. Attempts were made to ferment with Fusarium stillage from an alcohol plant operating on wheat, and an amount of alcohol equivalent to 6-12% of that obtained from yeast fermentation was obtained. It was shown that Fusarium mycelium was not toxic to mice, which would indicate there was no objection to the use of a Fusanam-fermented stillage as feed. 

About 10 million gallons of the fermentation alcohol is derived from wastes such as sulfite liquor or whey, but the balance presently depends on damaged grain or sugar, crop surpluses and molasses. Relative costs of ethylene and carbohydrates will change this in a few years, but no reversal to ethanol-based ethylene is likely in this country for much longer, perhaps through 1990. ... 

An inevitable and commercially important byproduct of fermentation processes is yeast. This can be recovered, dried, and inactivated to form a valuable food ingredient. Although the brewing industry is the major source, the demand is sufficient to warrant the growing of selected yeasts primarily for this purpose. Henry [63] has described the production of dried Torula yeast, resulting from the fermentation of the waste sulfite liquors from paper production. 

Consideration of these facts naturally led to plans to use saccharified wood waste and sulfite liquor as sources of fermentable sugar. Large potential supplies of these were available, and the economic factors which affect their use in peacetime did not enter into the picture as serious deterrents in the emergency. Faith and Hall (41) summarize the wood hydrolysis process of Scholler as modified by work in the United States. 

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