The selective absorption and recovery of hydrogen isotopes in an inert gas at 400°C, and their desorption at 800°C have been experimentally investigated by use of a zirconium particle packed bed. The gases used are H₂-Ar, D₂-Ar and H₂-D₂-Ar mixtures. The absorption rates of the hydrogen isotopes are confirmed to be fast enough so that this absorption method can be used as a hydrogen recovery process in the fuel cycle of a fusion reactor. The length of the absorption zone for D₂ in the zirconium bed is about twice as long as that for H₂.
For the breakthrough of hydrogen isotopes in the H₂-D₂-Ar mixture, the hydrogen isotopes flow out in the sequence of D₂, HD and H₂. The major reason is believed to be that the absorption rate and the solubility of hydrogen are greater than those of D₂ .
In the case of desorption process of the hydrogen isotopes, Fick's law diffusion equation in a zircorium particle can describe the experimental results fairly well.