Development of integrated system combining parallel-connected microbial fuel cells and microbial electrolysis cell for green hydrogen production

The growing demand for sustainable wastewater valorization and renewable hydrogen energy has amplified the need for systems capable of recovering energy and producing hydrogen without external electricity input. In this study, ten single microbial fuel cells (MFC) were connected in parallel to enhance power generation, and the electricity produced was controlled using a power management system. The energy was then directly supplied to a microbial electrolysis cell (MEC) in real time and stored in a battery prior to the MEC operation. When directly connected, the MFC–MEC system achieved a hydrogen production rate of 0.08 m³/m³/d, while the battery-assisted mode reached 0.66 m³/m³/d, demonstrating an eight-fold increase. These findings demonstrate the feasibility of integrated MFC–MEC systems for self-powered hydrogen production, offering a potential pathway for transforming organic wastewater into hydrogen as a renewable energy carrier.