ABSTRACT
Electricity generation in a microbial fuel cell (MFC) using carbon monoxide (CO) or synthesis gas (syngas) as a carbon source has been demonstrated recently. While the majority of MFCs have been tested at ambient or mesophilic temperatures, thermophilic systems warrant evaluation because of the potential for increased microbial activity rates on the anode. It has been indicated that thermophilic MFCs, which are operated at thermophilic temperatures (>50°C), are potentially superior to mesophilic MFCs operated at mesophilic temperatures (30–40°C) in terms of performance, reaction activity, durability and substrate range. Considering that the syngas temperature at the exit of the gasification process could be in a range of 45 to 55°C, the operation of the MFC at thermophilic temperatures might be preferable because it eliminates the need for syngas cooling and might lead to a higher biocatalytic activity. A thermophilic MFC-based process of syngas conversion to electricity might offer several advantages, such as high Coulombic efficiency and biocatalytic activity in the presence of carbon monoxide and sulfur components. This article reviews the thermophilic microorganisms (carboxydotrohs and exoelectrogens) involved in the generation of electricity in CO/syngas-fed MFC and the design considerations to overcome the practical challenges for operating an MFC on syngas at thermophilic temperatures.
