Enhanced electricity generation in direct glucose alkaline fuel cell combined with microbial fuel cell

The aim of this study was to investigate the feasibility of combining direct glucose alkaline fuel cell (DGAFC) with microbial fuel cell (MFC) process. The system of two DGAFC cells combined with an MFC cell was successfully operated for the first time with 1 g/L glucose in 50 mM carbonate buffer solution at a pH of 10.5. The combined system achieved 99% of Coulombic efficiency and produced 6.68 and 1.80 times the total Coulombs of two DGAFC cells and one MFC cell, respectively. No accumulation of gluconic acid and high glucose mineralization were detected in the combined system within 72 h. High performance of the combined system was attributed to the synergistic effect between glucose conversion to gluconic acid in the DGAFC and its utilization by electrochemically active bacteria and fermenters in the MFC. Our results could be useful for developing novel glucose fuel cell.