Tuesday, April 20, 2010
LL Conference Facility (Hilton Clearwater Beach)
Rebecca Garlock1, Venkatesh Balan
2, Bruce E. Dale
2, Venkata Ramesh Pallapolu
3, Y.Y. Lee
3, Youngmi Kim
4, Nathan S. Mosier
4, Michael R. Ladisch
4, Mark T. Holtzapple
5, Matthew Falls
5, Rocio Sierra
5, Jian Shi
6, Mirvat A. Ebrik
6, Tim Redmond
6, Bin Yang
6, Charles E. Wyman
6, Bryon S. Donohoe
7, Todd B. Vinzant
8, Richard T. Elander
9, Bonnie Hames
10, Steve Thomas
10 and Ryan E. Warner
11, (1)Chemical Engineering and Materials Science, Michigan State University, Lansing, MI, (2)Deparment of Chemical Engineering and Materials Science, DOE Great Lakes Bioenergy Research Center, Michigan State University, Lansing, MI, (3)Chemical Engineering, Auburn University, Auburn, AL, (4)LORRE/Ag. and Bio. Engineering, Purdue University, West Lafayette, IN, (5)Chemical Engineering, Texas A&M University, College Station, TX, (6)Center for Environmental Research and Technology Department of Chemical and Environmental Engineering Bourns College of Engineer, University of California at Riverside, Riverside, CA, (7)Biosciences Center, National Renewable Energy Laboratory, Golden, CO, (8)Chemical and Biosciences Center, National Renewable Energy Laboratory, Golden, CO, (9)National Bioenergy Center, National Renewable Energy Laboratory, Golden, CO, (10)Ceres, Inc., Thousand Oaks, CA, (11)Genencor, A Danisco Division, Palo Alto, CA
During the ethanol production process, a pretreatment step is necessary prior to enzymatic hydrolysis for effective conversion of lignocellulosic biomass to soluble sugars. For the biorefinery, the choice of pretreatment method is not trivial, as there are a number of different thermochemical pretreatments and each has unique characteristics. Because of this, it is extremely important to have a common basis and set of analytical methods when evaluating the differences between pretreatment methods.
For this project, six different chemical pretreatments were compared as part of the Consortium for Applied Fundamentals and Innovation (CAFI): ammonia fiber expansion [AFEX] (Michigan State University), dilute sulfuric acid (University of California-Riverside), lime (Texas A & M University), liquid hot water (Purdue), soaking in aqueous ammonia [SAA] (Auburn), and sulfur dioxide impregnated steam explosion [SO2] (University of California-Riverside).
For each of these pretreatments, material balances were analyzed around the optimal pretreatment and subsequent enzymatic hydrolysis of a common feedstock, Dacotah switchgrass. All material balances were based on 100kg of dry biomass entering pretreatment. Washing following pretreatment was considered optional and if performed, was also included in the material balance. Composition analysis was to be performed on all solid/slurry streams and monomeric and oligomeric sugar content was to be determined for all liquid streams. Water use during the entire process was also to be reported, with particular attention given to the pretreatment and washing steps. Enzymatic hydrolysis experiments were performed under the same experimental conditions and enzyme loadings. For each pretreatment, the mass closure for the key species and the glucose, xylose and lignin solubilization for each stage were reported and these results were compared between pretreatments.
