Design and the Study of the Mobile Solid Oxide Fuel Cell System with Hydrogen Generation

Solid oxide fuel cells (SOFCs) offer high efficiency and excellent fuel flexibility, yet their deployment has largely been restricted to stationary applications, such as power plants. This study presents a self-sustaining mobile SOFC system that generates hydrogen via the hydrolysis of NaBH4 using recovered water, which is obtained from the condensation of SOFC anode off-gas. Unlike conventional systems that rely on external hydrogen supplies or separate reformers, the proposed system establishes a closed-loop process between power and hydrogen generation, enabling a certain degree of autonomous operation in off-grid or remote environments. The effects of key operational parameters─water inflow rate, catalyst dosage, and recirculation ratio─are systematically evaluated. The results show that when the water inflow rates of a single reactor are 0.05, 0.10, and 0.15 mL·min–1, and the gas cylinder supply rates are 0.0243, 0.0639, and 0.1067 kg·h–1, respectively, long-term stable power output can be achieved, with corresponding SOFC power of 0.347, 0.839, and 1.23 kW. When the catalyst dosages are 0.2 and 0.4 g, with corresponding gas supply rates of 0.0496 and 0.0874 kg·h–1, the SOFC output power reaches 0.666 and 1.07 kW, respectively. As the recirculation ratio increases, the power first rises and then decreases, while the overall fuel utilization also increases. When the catalyst dosages of a single reactor are 0.2, 0.3, and 0.4 g, the maximum system efficiencies reach 44.0%, 42.6%, and 40.9%, respectively, while water recovery rates of 25.1%, 32.7%, and 45% are achieved at a recirculation ratio of 0.6.