Abstract: The experimental principle, device, sample preparation, test procedures and data processing of volumetric adsorption isotherm are introduced in detail. It was proved that the adsorption performance of 5A molecular sieve for CO₂, N₂ and H₂ was better than that of the 13X molecular sieve at liquid nitrogen temperature and low pressure. On the basis of analyzing the adsorption isotherms of 5A and 13X molecular sieves to CO₂, N₂ and H₂ at liquid nitrogen temperature and low pressure, the characteristics of adsorption isotherms of 5A and 13X molecular sieves at LNG and LH₂ temperatures were analyzed. The adsorption isotherms of 5A and 13X molecular sieve obtained under test at liquid nitrogen temperature and low pressure can provide good reference data for engineering design.

Key words: molecular sieve, adsorption isotherm, cryogenic vessel