Absorption and Capacity of Hydrogen with a La-Ni Alloy Particle Bed

Abstract

Deuterium and tritium have to be recovered from mixtures of hydrogen isotopes and inert gas in the fuel cycle of a fusion reactor, since the hydrogen isotopes have to be used as fuel and helium also has to be removed as ash or sweep gas. The high recovery efficiency at the low concentration of hydrogen is of great concern in the fuel cycle because tritium is radioactive and valuable. A metal particle bed is one of the most useful ways of the separation of hydrogen isotopes and inert gases. In this study the capacity and absorption rate of hydrogen at low concentrations were experimentally investigated using the particle bed of La-Ni alloys such as La3Ni and La2Ni3. H2-Ar mixtures containing 1% to 10% H2 were used, and the flow rate of the mixture was 116 NTP ml/min. In order to obtain the temperature dependence of hydrogen capacity (hydrogen atoms/alloy molecule) and absorption rates, the experiments were carried out in the temperature range 25–200 °C.