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Title: Production of ethanol from lignocellulosic materials using thermophilic bacteria

Miscellaneous ·
OSTI ID:5719965

The production of ethanol from lignocellulosic materials, e.g. wood, agricultural residues, and municipal solid wastes, is considered. The conversion of these materials to ethanol in the US could annually yield approximately 430 million tons ethanol, or about 9.8 quads, within the next 20 years. Thermophilic bacteria have advantages over yeasts for ethanol production because various species produce an active cellulase enzyme and utilize pentose sugars. However thermophiles have lower ethanol tolerance and usually lower ethanol yields. The potential of thermophilic ethanol production from hardwood chips is examined in detail. It is concluded that if high ethanol yield can be achieved this process could have economics competitive with either ethanol production from corn via yeast or synthetic production from ethylene. Low ethanol tolerance is not a major problem provided concentrations {ge} 1.5% are produced, ethanol is continuously removed from the fermentor, and IHOSR/extractive distillation is employed. Research was undertaken aimed at closing the gap between the attractive potential of thermophiles for ethanol production, and that which is possible based on present knowledge, which is not practical. Major topics were the activity of Clostridium thermocellum cellulase on pretreated mixed hardwood and Avicel in vivo, continuous culture of C. thermocellum on pretreated mixed hardwood and Avicel, and the continuous culture of Clostridium thermosaccharolyticum at high xylose concentrations in the presence and absence of ethanol removal.

Research Organization:
Dartmouth Coll., Hanover, NH (United States)
OSTI ID:
5719965
Resource Relation:
Other Information: Thesis (Ph. D.)
Country of Publication:
United States
Language:
English