Model-based Evaluation of the Effect of Temperature on Electric Power Generation in Microbial Fuel Cells

To assess the effect of temperature on the electric power generation of a microbial fuel cell (MFC), a series of experiments was conducted across a 5–55°C temperature range. We found that the currents generated were not proportional to the temperature, with the currents at 15 and 45°C higher than those at other temperatures. In order to determine the reason for this, a mathematical model, using a diffusion layer in an MFC, was developed, and analysis of this model suggested that the MFC temperature characteristics were caused by aerobic and anaerobic reactions being lower at 15 and 45°C. Our calculations indicated that the consumption of organic compounds predominantly occurred at specific temperatures and that diffusion of the compounds affected the current. These calculations made it possible to estimate the influence of aerobic and anaerobic reactions on power generation in the MFC within a prescribed temperature range. This work suggests that, using this model, competi tive reactions in electrogenic bacteria could be controlled by setting the correct temperature.