(381b) Hydrogen Production from Biomass Via Microbial Electrolysis

Authors: 
Lewis, A., University of Tennessee
Borole, A. P., Oak Ridge National Laboratory

Production of gasoline and diesel from plant biomass requires significant deoxygenation of the biomass. Biooil produced via pyrolysis contains over 30 wt.% oxygen requiring significant amount of hydrogen for upgrading to biofuels. We report on use of microbial electrolysis for extraction of hydrogen from water-soluble carbon compounds associated with biooil, improving the hydrogen as well as carbon conversion efficiency of the process.

The conversion of key components of the biooil aqueous phase to hydrogen will be reported. The primary parameters for development of the microbial electrolysis cell (MEC) process include current density, coulombic efficiency, applied voltage and organic loading. The relationship between these parameters will be discussed. The microbial consortium active in the anode chamber represents a complex community with exoelectrogens and fermenting organisms. The substrate specificity and stability of the consortium for treatment of the pyrolysis-derived biooil aqueous phase will be presented. A preliminary current density of 0.56 mA/cm2 has been achieved thus far, along with the complete removal of acetic acid, furfural, and hyxdroxymethylfurfural within 48 hours (undetectable by HPLC) with an organic loading rate of 2.5 g/Lr/day. These results demostrate the ability of MEC systems to remove racalcitrant compounds found in biooil and shows the potential of these systems for increasing the overall energy efficiency in related bioprocesses through removal of inhibitory compounds, water recycling, and hydrogen production.