Optimization of catalyst dosage and total volume for extendible stacked microbial fuel cell reactors using spacer

Abstract Reactors stack may be one of the most viable methods for microbial fuel cells (MFCs) scaling up. Optimization of catalyst and total reactor volume is necessary for stacked MFCs. Optimization of active carbon dosage (10 mg/cm2) or adding a small amount of Pt/C (1/10 of the common quantity) into active carbon can both improve reactor performances with relative low catalyst cost. One stacked unit set up with four cubic MFCs is built in this research, which spacers are used to minimize the distance of cathodes and two anodes share mutual chambers. The total volume of stacked unit is reduced by 23.8%, without adversely affecting performance, including start up, power density and columbic efficiency. Theoretically, more stacked units can be extended using similar stack structures in this study.