Evaluation of hydrogen production and internal resistance in forward osmosis membrane integrated microbial electrolysis cells

In order to enhance hydrogen production by facilitated proton transport through a forward osmosis (FO) membrane, the FO membrane was integrated into microbial electrolysis cells (MECs). An improved hydrogen production rate was obtained in the FO-MEC (12.5 ± 1.84 × 10−3 m3 H2/m3/d) compared to that of the cation exchange membrane (CEM) - MEC (4.42 ± 0.04 × 10−3 m3 H2/m3/d) during batch tests (72 h). After an internal resistance analysis, it was confirmed that the enhanced hydrogen production in FO-MEC was attributed to the smaller charge transfer resistance than in the CEM-MEC (90.3 Ω and 133.4 Ω respectively). The calculation of partial internal resistance concluded that the transport resistance can be substantially reduced by replacing a CEM with a FO membrane; decrease of the resistance from 0.069 Ω m2 to 5.99 × 10−4 Ω m2.