Absorption and evolution of hydrogen in/from ZrV_1.9Fe _0.1 particle bed at hydrogen production temperature

A bed of ZrV1.9Fe0.1 particles packed between cylindrical-annular tubes was studied as a tool to absorb and evolve hydrogen reversibly at higher temperature, where hydrogen is produced by steam-reforming reaction of methane or thermo-chemical decomposition of water using nuclear heat. The alloy had a sufficient absorption capacity even at 973 K and showed temperature rise in the bed during hydrogen absorption without any external heating. The experimental absorption and evolution rates ranged maximally to 170 and 80cm3 (NTP)/s, respectively. The hydrogen absorption rate was constant until the hydrogen absorption amount approached its saturated value. The ZrV1.9Fe0.1 particle bed evolved hydrogen with a constant rate in proportion to the heating rate. The hydrogen evolution rate was regulated easily by raising or lowering the heating rate. Thus, the alloy bed was found to provide a promising tool to recover and evolve hydrogen at steam-reforming temperature.