Microbial fuel cells: Control-oriented modeling and experimental validation

Microbial fuel cell (MFC) is a promising technology that uses bacteria to produce electricity through chemical reactions. While MFC is highly efficient, environment-friendly, and independent from limited sources, control-oriented modeling and control studies that aim to improve the power output have been limited. In this paper a control-oriented dynamic model with state-space representation is presented for an MFC system, by accommodating the physical principles of MFCs while judiciously making simplification decisions. For model validation, a membrane-less single-chamber MFC prototype was designed and fabricated. The MFC was inoculated with the model representative electricigenic bacterium Geobacter sulfurreducens strain PCA and fed with a substrate, acetate, which serves as the electron donor. Experimental results show that the identified model is able to predict well the evolution of open-circuit anode potential, cathode potential and substrate concentration. For example, the root-mean-square error (RMSE) of the anode potential is 0.0257 V, over the experimental anode potential range of 0.21 V, and the RMSE error of the cathode potential is 0.0240 V, over the experimental cathode potential range of 0.20 V.