Project Number: 1935-41000-083-02
Project Type: Specific Cooperative Agreement

Start Date: Sep 28, 2009
End Date: Sep 27, 2012

Objective:
Develop pretreatment and fermentation processes to convert lignocellulosic materials such as barley straw, barley hulls, DDGS, and other crop biomass into fuel ethanol and value-added coproducts. This work complements present ARS work to develop advanced bioconversion process for production of cellulosic ethanol and value-added co-products that can be integrated into an existing fuel ethanol plant. The first step in a lignocellulosic biomass bioconversion process normally is pretreatment to open up the structure and subsequently allow increased enzymatic hydrolysis. Soaking in aqueous ammonia (SAA) has been proven to be effective as a pretreatment method of agricultural residues, such as corn stover, corn fiber, barley hull, switchgrass, etc. In this study, SAA will be employed for the pretreatment step and subsequent conversion of SAA pretreated biomass will be investigated.

Approach:
The composition of specific types of biomass studied in this project will be determined using standard procedures for biomass analysis. Then, pre-treatment processes based upon Soaking in Aqueous Ammonia (SAA) technology will be developed and optimized for each biomass source. SAA will open up the structure of the biomass and subsequently allow increased enzymatic hydrolysis. This pretreated biomass will be subject to saccharification using commercial cellulases with xylanase supplements. The conversion of biomass to free sugars will be monitored by HPLC and standard methods of analysis. Once saccharified, the sugars will be fermented by traditional brewers yeast. In other studies, pre-treated biomass will be simultaneously saccharified and fermented to directly produce ethanol from the pretreated biomass in one step.