PATTERN PROGRESS
Waste Sulfite Liquor Utilization Through the years, l&EC has been one of the most important repositories of f u n d a m e n t a l a n d applied information. Each m o n t h , l&EC carries a report on progress m a d e in various fields in the chemical industry, s h o w i n g h o w this progress m a y have been fostered b y original articles published in earlier volumes of l&EC. This m o n t h , the editors look a t the advances m a d e in the utilization of w a s t e sulfite liquor since publication of a n original paper o n this subject b y H e r m a n V . Tartar, in the 1 9 1 6 l&EC. While almost every sulfite pulp mill i n the country supplied helpful information for this article, especially helpful a n d complete background i n f o r m a tion w a s supplied b y A v e r i l l J . W i l e y , Sulfite Pulp Manufacturers' Research League, a n d W . E. Byron Baker, N e w York a n d Pennsylvania Co., Inc., Lock H a v e n , Pa.
I N 1916, when spent sulfite liquor was being used to lay dust on city streets, a method for producing alcohol from waste sulfite liquor was reported NEERING
in INDUSTRIAL AND E N G I CHEMISTRY. H o w e v e r , it
wasn't until 1944 that t h e Puget Sound Pulp and T i m b e r Co. reached a n agreement with t h e Government to construct a n d operate a plant for the production of almost 2,000,000 gallons of alcohol annually from this waste. 1916 to 1944 is a long time, but these early efforts were a m o n g the very first to demonstrate that a truly refined chemical of definite fixed composition could be prepared in a technically satisfactory m a n n e r from waste sulfite liquor. T h e r e are now three major operations on t h e North American continent using t h e process developed by Charles M a r c h a n d a n d reported in l & E C in 1916. T h e Puget Sound Pulp a n d T i m b e r Co., Bellingham, W a s h . ; t h e O n tario Paper C o . , Thorold, O n t . ; a n d t h e C a n a d i a n International Paper Co., Gatineau, Q u e . , a r e all making alcohol from spent sulfite liquor on a commercial basis. T h e economics of making alcohol from waste sulfite liquor vary from plant to plant, b u t t h e process has been demonstrated to be commercially feasible a n d is of considerable interest. Years of technical contributions have resulted in improvements at every stage of t h e process from pulping to alcohol recovery, so t h a t t h e production is now more than 3,000,000 gallons of 195-proof ethyl alcohol annually. Furthermore, as a result of novel improve-
ments in processing, t h e alcohol meets t h e high standards set by t h e recent production of synthetic alcohol. Marketing presents a problem, however, because of t h e excessively high freight rates from t h e West to the points of heavy usage. T h e same technical possibilities of waste sulfite utilization were concurrently recognized in other sulfite p u l p - p r o d u c i n g countries, where t h e economic balance was more favorable. By 1920, there were 21 plants in operation in Europe. While some of these plants have discontinued operations, they have been joined by others with increased production a n d improved processes. J u s t o n e of these companies, M o och Domsjô in Sweden, reported t h e production of over half a million gallons of 100proof alcohol in September 1956. This company not only makes alcohol but converts a large portion of it into a n extensive series of other refined organic chemicals. This has been going on for some years, so that now in t h e operation of this t h e world's largest plant making ethyl alcohol from sulfite liquor, the c o m p a n y m a y justifiably be considered a n important producer of refined chemicals, including special products m a d e from various types of cellulose ethers. Various types of yeast a r e m a d e from spent sulfite liquor. O n e of the world's unsung a n d little known big research a n d development accomplishments occurred in G e r m a n y in the first years of World W a r I I . T h e G e r m a n "four-year p l a n " under Goering p u t t h e torula yeast process through t h e laboratory a n d pilot
plant stages and on to full scale commercial production in a dozen large pulp mills in a period of time that compares well with the better known U . S. accomplishments on the atomic b o m b . T h e G e r m a n high c o m m a n d hoped to be self-sufficient in protein foods a n d very nearly accomplished its objective. After t h e war, t h e same basic process was used in a plant at Rhinelander, Wis. M u c h engineering thought a n d effort has gone into development of methods for evaporating and burning spent sulfite liquor. However, t h e economics have never been more t h a n marginal. A few important steps were m a d e in the application of lignin salts from the liquor in t h e tanning of leather, wherein the molecular structure of t h e lignin plays a very definite chemical role. T h e Robeson Process Co. has been consistently successful in this field of a p plication, creating a growing market over t h e years. O t h e r applications for lignin products a r e in making binders, bonding agents, a n d dispersing agents. H e r m a n V . T a r t a r , in the 1916 l & E C , w r o t e : " I n spite of all this experimental work, however, this material (waste sulfite liquor) is still classed as a waste. Considering t h e a m o u n t , it is one of the most valuable waste materials known t o industrial chemistry." T h a t statement is still true for the industry as a whole, even though there a r e a n u m b e r of instances where a very few mills now have complete processes to utilize the organic matter from t h e "other half of the t r e e " which is contained in t h e spent sulfite liquor. But research efforts will, one day, achieve the industry's goal of t h e complete utilization of the spent sulfite liquor. Averill J . Wiley, technical director of the Sulfite Pulp Manufacturer's Research League, wrote: " T h o s e of us w h o a r e making a career of research on spent sulfite liquor feel that we are definitely close to the real answer w e have been seeking all these years. O u r research effort is always filled with a touch of excitement with something new coming u p daily."
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