Enhancing hydrogen production efficiency in microbial electrolysis cell with membrane electrode assembly cathode

Microbial electrolysis cell is a device which can produce hydrogen gas from biomass through microbial catalyzed process and thus reduce the organic matter. For the real application in wastewater treatment, the scale-up of microbial electrolysis cell is an important issue but few tests were conducted with relatively large size. In this study, a 3.7 L microbial electrolysis cell (liquid volume 3.2 L) equipped with a membrane electrode assembly cathode was designed and tested. The internal resistance was examined, hydrogen generation and organic removal performance was investigated under different conditions. A maximum overall hydrogen efficiency of 41% was achieved at an applied voltage of 1.2 V with acetate as substrate, corresponding to a volumetric hydrogen production rate of approximately 0.12 m3 H2/m3 reactor liquid volume/day. The results obtained in this study could help to further develop pilot-MEC for practical applications.