Hydrogen isotope separation using particle beds of LaNi₃Al₂ hydride

An experimental study was carried out for evaluating the performance of hydrogen isotope separation using an LaNi₃Al₂ hydride bed. The isotope effect in the uptake of hydrogen isotopes and the rate constants of hydriding and isotopic exchange between hydrogen and deuterium are given as indications of its effectiveness. These values were determined on the basis of the comparison of experimental data with numerical solutions to the material balance equation for hydrogen or deuterium in a bed. The uptake of deuterium is larger than that of hydrogen below 200 °C. The activation energy of the rate constant of isotopic exchange is 31.8 kJ mol^-1, while that of the hydriding rate constant increases with increasing hydrogen concentration in the influent stream. The height equivalent to a theoretical plate in the LaNi₃Al₂ bed above 200 °C is comparable with that in a Pd bed.