(239f) Conversion of Fermentation Inhibitors and Byproducts in Biorefinery Recycle Water Into Electricity

Fermentation inhibitors accumulating in biorefinery process water can reduce biomass to ethanol yields significantly. In this work, microbial fuel cells (MFCs) were investigated for their ability to reduce the concentration of known fermentation inhibitors with consomittant production of electricity. Microbial fuel cells (MFC) are electrical devices that use microorganisms to convert soluble organic matter into electricity. The convesion of furfural, a xylose degradation product, and lignin degradation products such as vanillic acid and 4-hydroxybenzaldehyde was investigated. An improved MFC anode design demonstrated potential for high power densities and coulombic efficiencies. A 16S rRNA analysis was conducted to determine the composition of the unique exoelectrogenic microbial consortium enriched in the MFC. The consortium demonstrated broad substrate specificity, ability to handle high inhibitor concentrations with near complete removal, while maintaining long-term stability. This approach can lead to: 1) higher ethanol yields at high biomass loading, 2) improved water recycle and 3) electricity production to meet part of the biorefinery power needs.