Helium recovery and blanketing effect with the hydriding reaction of ZrCo

Abstract

The hydriding reaction with hydride materials such as ZrCo, which has low hydrogen equilibrium pressure at room temperature, can be used in the helium-3 purification process to remove tritium impurity from a mixture of helium-3 and tritium. However, the helium interferes with the hydriding reaction, so it is necessary to confirm whether the helium affects the reduction of the tritium partial pressure to the equilibrium pressure of ZrCo tritide. Various hydrogen and helium mixtures were applied to the hydriding reaction under two reaction temperatures and two final H/M ratios to determine whether helium affects the reduction of the hydrogen partial pressure. Regardless of the helium fractions in the feed gases, residual hydrogen pressures were similar to the equilibrium pressure of ZrCo hydride under the different temperature and final H/M ratio conditions. Applying ZrCo hydriding reaction with a circulation loop, the helium-3 purification process can efficiently remove the tritium impurity without creating the blanketing effect.