Verification of vacuum regeneration for cryogenic molecular sieve bed

• CMSB was applied for helium-3 purification. • Vacuum regeneration was compared with gas purging. • Adsorption capacities were comparable for both methods. • Distinct cool-down characteristics were observed. • Vacuum regeneration is applicable to helium-3 recovery. Cryogenic adsorption, referred to as Cryogenic Molecular Sieve Bed (CMSB), is one of the technologies capable of purifying and recovering helium-3 produced in tritium storage systems. In typical adsorption process using temperature swing adsorption, the regeneration step to remove impurities adsorbed on the adsorption bed is performed by heating and purging with either a portion of the product gas or an inert gas. To enhance the recovery efficiency and purity of helium-3, vacuum regeneration can be employed as an alternative to gas purging. This study evaluated the applicability of the vacuum regeneration for CMSB in the helium-3 recovery system. The adsorption performance of the two regeneration methods, gas purging and vacuum regeneration, was compared experimentally. Vacuum regeneration was confirmed to be reliable and demonstrated comparable performance to the gas purging method.