Multi-component behaviors of hydrogen isotopes adsorbed on synthetic zeolites 4A and 5A at 77.4 K and 87.3 K

We already reported the experimental isotherms for H2 and D2 adsorbed onto synthetic zeolites 5A (SZ-5A) and 13X (SZ-13X) at 77.4 K and the experimental multi-component behavior of H2–D2 or H2–HD–D2 adsorbed onto these adsorbents, where the isotherms were approximated by the expression derived from a thermodynamic adsorbed-solution model and the separation factors were interpreted with the ideal adsorbed-solution (IAS) theory. In this work, H2 and D2 isotherms on synthetic zeolite 4A (SZ-4A) were measured at 77.4 K and 87.3 K, and separation factors were investigated in the systems of H2–D2 and H2–HD–D2 at the same temperatures, in addition to the examination on SZ-5A at 87.3 K. The isotherms on SZ-4A at both temperatures are fitted with the model expression as well as on SZ-5A and SZ-13X, and also the separation factors are described with the IAS theory. The results show the high performance of SZ-4A for hydrogen isotope separation relatively to that of SZ-5A or/and SZ-13X.