Extraction in Alcoholic Fermentation. Final Report, January 1, 1980-March 31, 1982

摘要

Production of fuel alcohol in a small scale is hampered by difficulty in obtaining good conversion of substrate to ethanol and variability of ethanol concentration in the product. Production of absolute ethanol suitable for blending with gasoline is not presently possible in a small scale using techniques used commercially. This research addressed the problem of improving alcohol productivity during fermentation and explored the feasibility of employing a solvent extraction procedure by fermentation. Yeast productivity averaged 158 and 26 grams ethanol per viable cell per hour, at 2.5 to 5% and 6 to 10% alcohol, respectively, in the medium. Cell recycling and retention of yeast cells in the fermentor sustained high alcohol productivity. Direct dodecane extraction of ethanol from dilute solutions was not feasible. However, at elevated temperatures (70 exp 0 C) and alcohol concentrations in excess of 50%, equilibrium alcohol concentration in an anhydrous dodecane phase reached 2.5%. Absolute ethanol was obtained by heating the dodecane phase to 110 exp 0 C and condensing the vapors. Activated carbon selectively absorbed ethanol from dilute alcoholic solutions. When the activated carbon bed was regenerated by heating at 80 exp 0 C, vapors that left the bed and condensed had 65% ethanol. A simple process for producing absolute ethanol by fermentation was developed by combining carbon adsorption to concentrate the ethanol and dodecane extraction to produce the absolute ethanol. 7 references, 5 figures, 5 tables. (ERA citation 08:057025)