Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: February 10, 2005
Publication Date: February 10, 2005
Citation: Saha, B.C. 2005. The present and future of biorefinery research at USDA [abstract]. International Workshop on Biorefinery. p. 19-20. Technical Abstract: In the U.S., the production of fuel ethanol from corn starch is expected to reach more than 3.4 billion gallons in 2004, up from 2.81 billion gallons in 2003. Developing ethanol as fuel, beyond its current role as fuel oxygenate, will require developing lignocellulosic biomass as feedstock because of its abundance and low-cost. Biorefinery refers to the conversion of biomass feedstock into a variety of products for the food, feed, chemical, and energy industries with minimal waste and emission. The biorefinery concept is similar to petroleum refineries which generate multiple products from petroleum. The Bioenergy and Energy Alternatives National Program (NP 307) at the Agricultural Research Service (ARS) of the U.S. Department of Agriculture (USDA) has undertaken a wide variety of innovative biorefinery research projects dealing with the development of fuel ethanol from waste and underutilized agricultural residues and herbaceous crops. These sugar platform based projects involve feedstock production and preprocessing, pretreatment and fractionation, enzymatic depolymerization, fermentation of multiple sugars, and downstream processing for efficient recovery of fermentation products. In addition, these projects involve development of new improved and highly efficient enzymes for use in biomass saccharification and robust recombinant stress tolerant microorganisms for use in the conversion of multiple sugars generated from lignocellulosic substrates to fuel ethanol. Research is also directed toward understanding the basic structures and functions of cell wall polysaccharides, identification and characterization of unknown inhibitors produced during feedstock pretreatment and their abatement/detoxification, and development of value-added coproducts from residues of biofuel production that reduces the net cost of ethanol. The mission of Bioenergy and Energy Alternative National Program is to develop technology for alternate energy systems and increase the sustainable use of agricultural feedstocks for biofuels that will create jobs and economic activity in America, reduce the Nation's dependence on foreign oil, and improve the environment. ARS brings biological and physical science together with engineering in a coordinated research program to develop the technology needed for successful biorefinery system. It also cultivates appropriate partnerships with other government agencies, universities, and industries in order to use resources more efficiently and achieve significant progress in a more effective way. Process integration of biomass pretreatment, enzymatic saccharification, fermentation of the hydrolyzate with product recovery will definitely help to reduce the conversion cost significantly. ARS has the capability to scale-up, economic analysis and transfer of the technology to private sectors for commercialization. The ARS funded, recently built National Corn-to-Ethanol Pilot Plant at Southern Illinois University at Edwardsville, Illinois, will help to evaluate ARS technology in a simulated commercial environment. In this presentation, the objectives and approaches of a few of the current biorefinery research projects will be described. ARS has initially targeted corn fiber, a byproduct of corn wet-milling, as a model lignocellulosic biomass for conversion to fuel ethanol because it contains about 20% residual starch which can be easily converted to glucose and has low lignin content. Integration of corn fiber to ethanol at the production plant is feasible and would result in about 10% increase in ethanol yield from corn. The barriers, comprehensive progress, and future prospects of ARS biorefinery research for production of fuel ethanol will be highlighted.