Co-production of hydrogen and electricity from macroalgae by simultaneous dark fermentation and microbial fuel cell

Abstract

In this study, a hybrid process of dark fermentation (DF) and microbial fuel cell (MFC), sDFMFC, was investigated for simultaneous H2 and electricity production from Saccharina japonica in a single reactor. The sDFMFC exhibited a considerably enhanced energy recovery owing to simultaneous H2/carboxylic acids (CAs) production by DF and electricity production by MFC consuming CAs. The co-production of H2 and electricity was confirmed by a time course of CAs concentration in sDFMFC. An excellent energy recovery of 17.3% was obtained from S. japonica with H2 yield of 110 mL/g-VS and maximum power density of 1.82 W/m2. The sDFMFC showed a diverse microbial community for a desirable microbial conversion of organic substrates. The results indicate that sDFMFC can be a promising single reactor process to produce H2 and electricity from various biomass feedstock with considerable cost savings while ensuring the strength of the individual DF and MFC process.