Efficient hydrogen recovery and purification from industrial waste hydrogen to high-purity hydrogen based on metal hydride powder

Flow-through reaction model of metal hydride powder for hydrogen recovery and purification from industrial by-product hydrogen to high-purity hydrogen is proposed. The hydriding mechanism of hydrogen storage alloy in the flow-through reactor is expounded. The results show that the evolution of bed temperature field leads to a unique increase in outlet hydrogen mole fraction compared to the case of pure hydrogen. In addition, the effects of operating parameters and reactor geometrical parameters are systematically investigated for performance optimization. The indexes of hydrogen absorption efficiency and effective metal hydride utilization ratio are introduced to evaluate the hydrogen recovery and purification performance of reactor. The optimum hydrogen absorption efficiency of 65 % with the effective metal hydride utilization ratio of about 0.8 could be achieved at the cooling water temperature of 373 K. This work contributes to the design and development of advanced hydrogen separation and purification technology.