Authors have been studying the adsorption or/and desorption behavior of H2 or/and D2 with synthetic zeolite packed-beds under the cryogenic condition of liquid nitrogen temperature, aiming at developing a pressure swing adsorption (PSA) process of hydrogen isotope separation useful for tritium processing in fusion fuel cycle and environmental tritium safety confinement, or convenient for deuterium production. We examined the mass transfer in the adsorption system of D2 diluted in H2 with zeolite packed-beds, experimentally and analytically. The results have been presented, where it is shown that the enrichment factor of D2 in packed-beds matches with estimated from the isothermal adsorption characteristics and that the mass transfer is controlled in the macro-pore media of adsorbents. In this work, the behavior of tracer HD added in a H2-D2 mixture with zeolite 5A and 13X packed-beds was experimentally investigated, and was analyzed by the curve-fitting as well as for the behavior of D2. In this report, the experimental results demonstrate that the breakthrough curves of HD exhibit analogous to those of D2 but reduced in the breakthrough time in comparison to the latter. The analytical results verify that the HD/H2 separation factor in packed-beds agrees with predicted from the isothermal adsorption characteristics, and show that the isotope effect on the mass transfer depends on the molecular mass effect.
