Adsorption of Noble Gases on H-Mordenite

Release of nuclear off-gas that contains various radioactive components to the environment could jeopardize public health and safety. Therefore a screening test was carried out to find suitable adsorbents for the removal of the radioactive noble gases from the reprocessing off-gas. The adsorption capacities of various adsorbents for Kr and Xe were investigated. Carbon based adsorbents such as Ambersorb 572, Merck, Ryujou-Shirasagi G2x4/6-3 and Molsievon X2M4/6 were found to have large adsorption capacities. The H-mordenite, a non-carbon based adsorbent prepared from natural mordenite by ion exchange with a HCl solution, demonstrated a large adsorption capacity for Kr almost comparable to that of activated charcoal. Since non-carbon based adsorbents have a very important feature, that is they are not susceptible to fire hazards, the adsorption equilibria of Kr and Xe on the H-mordenite adsorbent were more thoroughly studied. The adsorption experiments on the H-mordenite were conducted in the temperature range of 77 K to 353 K using a packed bed column. The adsorption isotherms obtained for the H-mordenite were successfully correlated with the vacancy solution model over wide partial pressure and temperature ranges.