(284a) Insights Into Hydrothermal Pretreatment of Cellulosic Biomass Through the DOE Bioenergy Science Center (BESC)

Insights into Hydrothermal Pretreatment of Cellulosic Biomass through the DOE BioEnergy Science Center (BESC)

Charles E. Wyman^1,2,3, Vanessa Lutzke^1,2,3, Samarthya Bhagia^1,2,3, and Rajeev Kumar^2,3

1 Chemical and Environmental Engineering Department

2 Center for Environmental Research and Technology (CE-CERT)

Bourns College of Engineering, University of California Riverside

Riverside, California 92507

3 BioEnergy Science Center, Oak Ridge National Laboratory

Oak Ridge, Tennessee 37831

Biomass is a unique resource for sustainable production of liquid organic fuels for transportation, and the cost and availability of cellulosic biomass make it a particularly promising feedstock to reduce petroleum dependence and associated greenhouse gas emissions.   Furthermore, many forms of cellulosic biomass contain a large fraction of the sugars glucose, xylose, arabinose, galactose, and mannose that can be fermented to fuel ethanol or other products with high yields.  However, costs of releasing these sugars from the hemicellulose and cellulose that comprise about two thirds or more of many forms of cellulosic biomass are currently high, and novel approaches are needed to reduce deconstruction costs while realizing high sugar yields.  Hydrothermal pretreatment based on heating biomass to around 180 to 200°C for about 10 to 20 minutes has important attributes of not adding acids or other chemicals and employing low cost materials of construction but suffers from sugar degradation at conditions that maximize cellulose digestion by enzymes.  In addition, solids from hydrothermal pretreatment, like those from other options, require higher downstream enzyme loadings to achieve high sugar yields than are desirable for low costs.  Therefore, pretreatment research at the BioEnergy Science Center (BESC) is focused on understanding and improving hydrothermal pretreatment to increase sugar yields from the combined operations of pretreatment and enzymatic hydrolysis while also lowering enzyme doses.  This research includes linking improved plants and advanced microbial systems being developed by BESC and seeking synergistic combinations that remove recalcitrance as an economic obstacle to low cost ethanol.  An update will be presented on hydrothermal pretreatment developments including results on the impact of lignin, pseudo-lignin, and hemicellulose on pretreatment effectiveness for batch and flowthrough hydrothermal pretreatment configurations.