Monday, April 30, 2007 - 1:50 PM

Steam explosion—the best pretreatment method during biomass to ethanol processing?

Renata Bura, College of Forest Resources, University of Washington, Winkwnwerder 104, Seattle, WA 98195-2100 and Jack Saddler, Forest Products Biotechnology, Wood Science, The University of British Columbia, 4609-2424 Main Mall, Vancouver, BC V6T1Z4, Canada.

Pretreatment is the most critical sub-process for enzyme-based biomass-to-ethanol conversion, affecting later hydrolysis and fermentation steps. Since no single lignocellulosic feedstock is likely to satisfy future demands for fuel ethanol production, future biomass-to-ethanol schemes require a robust pretreatment process able to accommodate a diverse range of feedstocks. This presentation will summarize past and current data on: robustness, substrate diversity and co-product availability from steam explosion pretreatment, based on agricultural, hardwood, softwood residues and mixed feedstocks, and the techno-economic-industrial feasibility of the process.

It has been accepted that flexibility to co-produce a mix of higher value products may be critical to otherwise marginally cost-effective bioconversion schemes based solely on fuel ethanol. The flexibility of the steam explosion process in terms of tailoring substrate characteristics for industry specifications will be demonstrated, based on the customization of pretreated substrate according to enzyme companies’ specifications. By changing pretreatment conditions, the substrates’ characteristics will vary, resulting in the formation of different types and proportions of hemicelluloses and lignins in water soluble and insoluble streams, thus creating the possibility for production of different co-products.