Dependence of adsorption of krypton and xenon by crystals of zeolite LiX and NaX on pressure and temperature

Abstract

Adsorption isotherms of xenon on crystals of zeolites LiX and NaX, and krypton on LiX, have been measured at different temperatures. These adsorption isotherms are at first convex towards the gas pressure axis and have an inflection point, while the differential heats of adsorption of xenon and krypton by zeolites increase with increasing adsorption, which is typical for adsorption on a sufficiently homogeneous surface with strong adsorbate-adsorbate attraction. Experimental adsorption isotherms of xenon and krypton on zeolites LiX and NaX are adequately described by simple equations which take approximate account of the interaction of the adsorbed molecules with each other. Temperature dependence of the equilibrium constants of adsorbate-adsorbent and adsorbate-adsorbate of these equations have been determined. These equations make it possible to calculate the adsorption values of xenon and krypton by zeolites LiX and NaX at different gas pressures and temperatures, as well as isosteric heats of adsorption at different adsorption values. The results of these calculations are in agreement with experimental data.