A hybrid thermochemical-biological process via pyrolysis and microbial electrolysis for conversion of biomass to biofuels, hydrogen and co-products
Tuesday, April 28, 2015
Aventine Ballroom ABC/Grand Foyer, Ballroom Level
Abhijeet P. Borole1, Alex Lewis
2, Shoujie Ren
3, Pyoungchung Kim
4, Xiaofei Zeng
5, Spyros Pavlostathis
5, Philip Ye
3 and Nicole Labbé
6, (1)Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, (2)Energy Science and Engineering, The University of Tennessee, Knoxville, Knoxville, TN, (3)Biosystems Engineering and Soil Science, The University of Tennessee, Knoxville, Knoxville, TN, (4)Center for Renewable Carbon, The University of Tennessee, Knoxville, Knoxville, TN, (5)Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, GA, (6)Center for Renewable Carbon, The University of Tennessee, Knoxville, TN
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 a hybrid thermochemical – biological process to generate bio-oil intermediate and biohydrogen to support biofuel production. Use of microbial electrolysis for extraction of hydrogen from water-soluble carbon compounds associated with biooil is described, which has potential to increase the hydrogen as well as carbon conversion efficiency of the process.
The conversion of key components of the biooil aqueous phase, including furfural, acetic acid and phenolic molecules to hydrogen was investigated. The primary parameters for development of the microbial electrolysis cell (MEC) process include current density, coulombic efficiency, applied voltage and organic loading. Electrochemical conversion efficiency was a function of the organic loading and concentration. The microbial consortium active in the anode chamber represents a complex community with exoelectrogens and fermenting organisms. The substrate specificity of the consortium for treatment of the pyrolysis-derived biooil aqueous phase was diverse and included Geobacter, Pseudomonas and Clostridialstrains indicating synergistic conversion processes. The results indicate the potential of the MEC process to produce renewable hydrogen which can enable production of drop-in fuels without the need for fossil fuels.
