抄録
The consumption of masses of fossil fuels has been serious environmental problems. The energy systems have to be changed from the fossil fuel over to the renewable energy. Hydrogen is expected as an energy carrier in the renewable energy systems, where also the hydrogen storage alloy has been considered and used as useful materials. Recently, we reported an effect of LiOH pretreatment using ultra high purity of 7N-H2 gas (99.99999% purity). Hydrogen absorption is drastically modified by the LiOH pretreatment even after significant air oxidation. In this paper, we report the effect of LiOH pretreatment on H2 absorption characteristics and pulverization behavior using low purity of H2 gas (4N-H2 gas, 99.99% purity) in considering the practical application. We measured the equilibrium characteristics after the initial activation and after 300 times of H2 sorption cycles using 4N-H2 gas with and without LiOH pretreatment. Additionally, pulverization behavior of the powder sample with and without LiOH pretreatment was investigated. From the measurements of the equilibrium characteristics and the sizes of sample particles, the effect of LiOH pretreatment indicated that less pulverization and less reduction in the hydrogen storage capacity were yielded after 300 times of H2 sorption cycles using 4N-H2 gas.
