PROCESS TECHNOLOGIES FOR PRODUCING BIOFUELS AND COPRODUCTS FROM LIGNOCELLULOSIC FEEDSTOCKS
Location: Bioenergy Research Unit
Title: Fuel Ethanol Production from Agricultural Residues: Current Status and Future Prospects
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: September 18, 2010
Publication Date: September 18, 2010
Citation: Saha, B.C., Qureshi, N., Nichols, N.N., Cotta, M.A. 2010. Fuel ethanol production from agricultural residues: current status and future prospects [abstract]. 14th International Biotechnology Symposium, September 14-18, 2010, Rimini, Italy. Paper No. 1158.
In 2009, the U.S. produced 10.6 billion gallons of fuel ethanol from corn starch. The Energy Independence and Security Act of 2007 requires that 36 billion gallons of renewable fuel be produced in 2022 of which cellulosic biofuel is to contribute 16 billion gallons. Currently, there is no commercial cellulosic ethanol plant in the U.S.A. Various agricultural residues such as corn stover, wheat straw, rice straw, and barley straw can serve as low-cost lignocellulosic feedstocks for conversion to fuel ethanol. The conversion of these feedstocks to fuel ethanol involves feedstock pretreatment, enzymatic saccharification, fermentation, and product recovery. The purpose is to present the outcome of our 5-year study on the production of fuel ethanol from agricultural residues, particularly wheat straw. Wheat straw is a primary agricultural byproduct for conversion in Europe.
We have just finished the scale-up (100 L) work on the production of ethanol from wheat straw based on optimized pretreatment, bioabatement of fermentation inhibitors, and simultaneous enzymatic saccharification and fermentation using a mixed sugar utilizing recombinant ethanologenic Escherichia coli. Our research dealing with ethanol production by the recombinant bacterium from liquid hot water, dilute acid, lime, and alkaline peroxide pretreated wheat straw under optimized conditions by separate hydrolysis and fermentation (SHF) and simultaneous saccharification and fermentation (SSF) will be presented. Data on batch, fed-batch, cell-recycle, and continuous production of ethanol from wheat straw hydrolyzate by the recombinant bacterium will also be presented. In addition, we will present our research data on the production of ethanol from barley straw. Barley straw can be easily mixed with wheat straw for use as a feedstock for ethanol production.
The problems and prospects of developing a cost-effective integrated process technology for production of fuel ethanol from lignocellulosic feedstock by fermentation and future directions of research will be highlighted.