MIXED COMMUNITY BIOREACTORS TO CONVERT LIGNOCELLULOSIC FEEDSTOCKS INTO THE LIQUID BIOFUEL BUTANOL
Bioenergy Research Unit
2011 Annual Report
1a.Objectives (from AD-416)
To evaluate pretreatment requirements and conversion efficiencies of lignocellulosic feedstocks into fermentation products using mixed culture bioreactors. Develop conversion technologies for conversion of fermentation acids into solvents (i.e., butanol).
1b.Approach (from AD-416)
Untreated and pretreated corn fiber will be fed to a mixed culture bioreactor that is optimized for the production of butyric acid. Product butyric acid will then be converted by solventogenic clostridia to produce fuel butanol.
The goal of the project is to convert corn fiber into butanol. Corn fiber was successfully pretreated for fermentation at the small pilot-plant scale using a dilute-acid catalyst. The hydrolysate was readily converted to butyric acid using a mixed culture fermentation. The project goals were completed and a manuscript was prepared describing a continuous system for converting butyric acid into butanol. The work describes steps that are needed to stabilize butanol production, which includes using a two-stage process, periodically re-inoculating with heat-shocked bacterium, and using in situ removal of butanol in order to control butanol concentration in the second stage. This represents the final report of reimbursable agreement 3620-41000-133-02R between ARS and Cornell University. The Authorized Departmental Officer's Designated Representative (ADODR) monitored the activities of this agreement via e-mail contacts.