Integration of an Advanced Cellulase-Producing Ethanologenic Bacteria with Pretreatment to Significantly Reduce the Cost of Ethanol from Biomass

70943 Biomass could provide a low cost, abundant feedstock for the production of fuel ethanol. Although substantial improvements have been realized, processing costs are still too high, largely due to pretreatment and enzyme production. This project will optimize a combination of pretreatment and subsequent fermentation processes. The approach is based on using an advanced recombinant organism that can produce an enzyme for the breakdown of cellulose to glucose and also can ferment glucose and other sugars (as well as many of their soluble polymers) to ethanol. In Phase I, sugarcane bagasse will be pretreated with varying levels of dilute acid at different temperatures, and the resulting soluble sugars and cellulose rich solids will be evaluated as substrates for ethanol production by the advanced recombinant organism. Pretreatment conditions that maximize total ethanol yields at each acid level will be defined, and the effect of pretreatment conditions on soluble sugar treatment needs, enzyme demands, and ethanol yields from soluble polymers will be determined. The results will be evaluated in a process engineering model to determine the ability of the technology to decrease the cost of chemicals for pretreatment, cut hydrolyzate conditioning costs, and reduce use of expensive cellulase enzymes. Commercial Applications and Other Benefits as described by the awardee: In a commercial plant, the technology should lower the cost of ethanol production. The increased use of ethanol would significantly cut carbon dioxide emissions, improve the domestic supply of transportation fuels, reduce our trade deficits, and improve energy security.