Alteration of Adsorption Selectivity of LSX Zeolite in Li+ and H+ forms towards CO2 and N2O

Abstract

Abstract The adsorption and textural properties of LSX zeolite after cation exchange both in LiCl and NH4Cl aqueous solutions have been evaluated from elemental analysis, XRD, N2 adsorption at 77K, and CO2 and N2O adsorption at 273K. Incorporation of Li+ and H+ results in a significant decrease of adsorption selectivity towards CO2 in a pressure range 0.01 - 1 Torr compared to the initial LSX in the K-Na form. This feature allows simultaneous quantitative sequestration of CO2 and N2O traces from contaminated gas flows, or can be useful for pre-concentration of these gases prior to catalytic utilization. Above 1 Torr adsorption selectivity rises to 1.0 for the unmodified LSX, but incorporation of Li+ and H+ increases it in the range 5 - 50 Torr, allowing adsorption purification of N2O from CO2 diluted an in inert gas flow under the applied conditions.