Tuesday, May 1, 2012
Napoleon Ballroom C-D, 3rd fl (Sheraton New Orleans)
Biorefinery process water generated as a result of biofuel production can be treated in anaerobic digesters or processed for water recovery via evaporators. Microbial fuel cells can potentially generate energy while enabling water recycle. Here, we report on treatment of process water generated from corn stover. Ability to convert residual organics and pre-treatment byproducts to electricity and the efficiency of the process were investigated. The results show complete removal of fermentation inhibitors such as furfural, HMF, phenolics and acetate from the stream, indicating potential to recycle water. A study of the effect of organic loading on coulombic efficiency indicated that undiluted process water results in poor energy recovery efficiencies. Controlled organic loading via dilution and partial recycle, however, results in electricity production at coulombic efficiencies greater than 50% . Other parameters such as degree of organic removal in one pass, potential limitations of cathode and assessment of the anode to handle high loadings under conditions where the electron sink is non-limiting were also investigated. Preliminary analysis of the inclusion of microbial fuel cells into the biorefinery process for bioenergy production in terms of sustainability, water use and process efficiency will also be discussed. Assessment of hydrogen production using microbial electrolysis cell treatment of the biorefinery process water will also be presented.