Enhancement of Electric Power Generation of Microbial Fuel Cells by Open/Closed and Parallel/Series Circuits

摘要

nRepeating discharge and charge modes (closed and open circuit: CC-OC) in a short cycle is effective in enhancing electric power generation of microbial fuel cells (MFCs). However, MFCs can not generate electricity during the OC. In order to eliminate the downtime, we introduced four MFCs, which were repeatedly switched on and off by turns using a program relay. Furthermore, series and parallel connections of MFCs were also discussed to enhance the stability of the power generation of the MFCs. As a result, the observed voltage at the CC mode by switching four MFCs in turns was 0.40 V, which was 1.4 times higher than that by the continuous operation of a single MFC. In addition, the voltage using a parallel circuit of four MFCs at the continuous CC mode was almost the same as 1.3 times that of a single MFC. The observed voltage at the continuous CC mode increased from 0.25 V in a single MFC to 0.35 V in a series connection of four MFCs. Furthermore, the voltages of a parallel connection of three trains of four MFCs, or that of four trains of three MFCs were increased to 1.2 V.