Transient Impurity Concentration of Absorption and Desorption in Metal Hydride

Biomass-derived hydrogen (Bio-H2) has been attracting much attention as a low environmental load type of hydrogen. Among the potential applications of Bio-H2, use as a fuel for polymer electrolyte membrane fuel cells (PEMFCs) would require the removal of contaminants. Therefore, we propose the use of metal hydride for the purification and storage of Bio-H2. Metal hydride can store a larger volumetric amount of hydrogen than that other hydrogen storage, and the hydrogenate is processed at near atmospheric pressure and room temperature. In addition, by exploiting the selective hydrogen absorption properties of metal hydride, we have successfully reduced the concentration of methane in the hydrogen using metal hydride, the storage performance of which was evaluated in our previous study. Pressure swing adsorption was used to reduce the contaminant concentration, which was measured as 3% of methane. For practical application, the hydrogen recovery rate over the hydrogen absorption and desorption processes is evaluated.