ADVANCED CONVERSION TECHNOLOGIES FOR SUGARS AND BIOFUELS: SUPERIOR FEEDSTOCKS, PRETREATMENTS, INHIBITOR REMOVAL, AND ENZYMES
Location: Bioenergy Research Unit
Project Number: 3620-41000-133-00
Start Date: Aug 09, 2009
End Date: Aug 08, 2014
The long-term goal of this project is to develop lignocellulosic materials as a feedstock for producing sugars and biofuels. The research will focus more specifically on the following objectives: Objective 1: Develop commercially-viable analytical tools that producers and biorefiners of lignocellulosic feedstocks can use to evaluate the quality of harvested biomass for enzymatic and fermentative conversion to ethanol and butanol and plant breeders can use to select superior cultivars for biorefining. Objective 2: Develop new, commercially-viable enzyme and/or protein systems that increase the efficiency of lignocellulosic saccharification. Objective 3: Identify components in lignocellulosic hydrolysates which reduce saccharification or fermentation efficiencies and develop commercially-viable mitigation strategies. Objective 4: Develop new technologies that enable commercially-viable pretreatment processes for lignocellulosic biomass, inhibitor abatement strategies, and enzyme preparations which are optimized for saccharifying particular lignocellulosic feedstocks.
Renewable biofuels have the potential to reduce U.S. dependence on imported oil, lower greenhouse gas emissions, and to further develop the rural economy. Renewable fuels produced from lignocelluloses should be able to replace up to 30% of the U.S. oil consumption. While technologically proven, commercializing lignocellulosic biofuels is stymied by prohibitively high processing and capital costs. There are opportunities to reduce expenses by developing higher-quality feedstocks, more active enzymes, better managing side-products, and using faster/higher yielding biocatalysts. Our research targets improvements in each of these areas. Crop quality for bioprocessing will be improved by collaborating with plant scientists to breed bioenergy cultivars, including reduced lignin mutants that are more amenable to processing, without sacrificing production yield. The enzymes used are too expensive because their specific activities are too low. Activities can be improved by creating balanced mixtures from blending individual enzymes selected for superior kinetics and by discovery of auxiliary proteins that aid cellulase binding to cellulose. Processing of biomass prior to fermentation releases a wide range of biologically active byproducts that can retard or stall fermentation and frustrate water recycling schemes. Biological abatement has the promise to selectively remove complex organic compounds without generating further waste. It is expected that when combined with an advanced pretreatment and engineered microbes, the final result will be a significantly improved process for converting lignocelluloses into sugars and renewable fuels.