A New Design Improves Performance of a Single Chamber Microbial Fuel Cell

摘要

A new design of MFC (MFC-A) whose main features were the assemblage or sandwich' arrangement of the anode-PEMcathode and the extended surface area of electrodes (higher electrode surface to cell volume ratio, ξ) exhibited a performance significantly superior to that of a similar cell (MFC-B, standard cell) where the electrodes were separated. The characterization experiments showed that the new design lead to a significant 70% reduction of cell internal resistance (R_(int)) compared to the standard cell. During the batch operation of the cells loaded with a model extract typical of hydrogenogenic fermentation of organic solid wastes and a sulphate-reducing inoculum, the maximum, open circuit potentials were 0.5 and 0.3 V whereas the average voltages were 0.21 y 0.18 V for MFC-A and MFCB, respectively. Maximum volumetric power P_V and anode density power P_(An) of the MFC-A were superior to those of the MFC-B by factors of 13.2 and 8.4, respectively. The experimental improvement factor was almost double of the expected (algebraic) factor 6.5. The P_V of the MFC-A (922 mW/m~3) was in the middle to high side of the range of P_V reported in the literature whereas P_(An) was in the low range of published results (38.4 mW/m~2). Finally, this work points out to the usefulness of the approach of increasing x and reducing R_(int) for improving MFC performance.