Continuous Fermentation to Produce Fuel Grade Ethanol. Final Report, September 15, 1981-October 15, 1982

摘要

The purpose of this project has been to demonstrate a commerical scale continuous fermenter. A 378.5 liter fermenter was constructed with plate glass sides so that the flow patterns could be easily observed. A heat exchanger, baffles, and a compressed gas agitator/oxygen sparger was added to the basic design. A total of 4 test runs were completed, each lasting from 2 to 4 days. Ground corn was cooked, liquefied, and saccharified. The resulting mash, including the corn solids, were used as the feedstock for the fermentations. The fermenter operated with a 5 h residency time to produce an 8 1/2% v/v beer. The specific ethanol productivity was 13 grams/liter volume/h, and the efficiency was estimated at 90% of the theoretical yield. The corn solids in the fermenter were kept in suspension by agitation provided by (1) the incoming feed, (2) the CO sub 2 gas produced by the fermentation, and (3) compressed gas that was sparged into the bottom of the fermenter. Specific recommendations for improvements and areas which need further research are presented. The major limiting factor with this fermenter, which now needs further research, is the speed of the saccharification. 13 refs., 6 figs. (ERA citation 10:051064)