(554a) Comparative Sugar Recovery Yields For Pretreatment Of Corn Stover And Poplar By Leading Technologies Followed By Enzymatic Hydrolysis Of The Remaining Solids

Pretreatment is essential to high yields and low costs for biological processing of cellulosic biomass to fuels and chemicals. A team experienced in biomass hydrolysis formed a Biomass Refining Consortium for Applied Fundamentals and Innovation (CAFI) to develop comparative data for leading pretreatment options of ammonia expansion, aqueous ammonia recycle, controlled pH, dilute acid, lime, and sulfur dioxide steam explosion using shared feedstocks, enzymes, procedures, and analytical methods. Controlled sources of corn stover and poplar wood were employed as feedstocks to determine the effect of considerably different classes of cellulosic biomass on performance. Comparative data were developed on sugar recovery for each feedstock during pretreatment and after digestion of the solids produced using different loadings and combinations of enzymes supplied by Genencor International. Standard protocols were applied to close material balances based on this data and used to determine overall sugar release from each combination of pretreatment and enzymatic hydrolysis. All pretreatments recovered high yields of sugars from the hemicellulose and cellulose in corn stover, although high pH technologies tended to be somewhat more effective. However, yields were much more variable for applications of the same technologies to poplar wood, and significant performance differences were observed among these pretreatments for the same poplar variety from two different locations. Overall, these results show the importance of linking selection of pretreatment technology with the feedstock used.