8-01: Effects of pretreatment technologies, enzyme formulations, enzyme loadings and biomass type on sugar yields and costs for coupling of leading pretreatments with enzymatic hydrolysis

The Biomass Refining Consortium for Applied Fundamentals and Innovation (CAFI) formed in 2000 recently completed its last funded study to determine comparative sugar yields from application of leading pretreatments to shared sources of cellulosic feedstocks followed by enzymatic hydrolysis of the resulting solids with a common source of enzymes, and this talk will highlight key findings for the applications to corn stover, poplar wood, and switchgrass pursued by the CAFI during its lifetime.  Material balances will illustrate the fate of key biomass components, with differences in conditions applied and impact on biomass deconstruction noted among pretreatments by ammonia fiber expansion (AFEX), ammonia recycle percolation (ARP), dilute acid, hot water, lime, soaking in aqueous ammonia, and sulfur dioxide steam explosion.  The effect of cellulase loadings and beta-glucosidase supplementation on release of glucose and xylose will be summarized, and information provided on changes in sugar release by introducing xylanase, beta-xylosidase, pectinase, and other enzymes into the mix.  In addition, insight will be shared on similarities and differences in sugar release from pretreatment and enzymatic hydrolysis of corn stover, poplar, and switchgrass to demonstrate how changes in a plant species impact performance by different pretreatments.  Key features of the enzymes applied will be outlined, and results from application of a common costing methodology will reveal important economic drivers.  Finally, key take home messages will be summarized to guide research, development, and commercialization of biomass feedstocks and deconstruction technologies.