The role of methanol inmicrobial fuel cells

Abstract

Several new technologies based on renewable energy resources are to be developed nowadays. Fuel cells are well-known examples and their enhancement is one of the most important goals of the scientists worldwide. In this work the operation of two fuel cells were compared, which are different in some principles: the microbial fuel cell (MFC) and the direct methanol fuel cell (DMFC). The MFC is a bioreactor converting chemical energy of organic compounds to electrical energy by catalytic reactions of microbes under anaerobic conditions. In the DMFC the liquid methanol (CH3OH) is oxidized in the presence of water at the anode generating CO2, H+ ions and the electrons that travel through the external circuit as the electric output of the fuel cell. The aim of this work was to decide and clarify the role of methanol. Based on the experiments we found that – although the microbes were able to form methanol – the electron flow was the result of the metabolic breakdown of substrates by the microbes in the MFCs.