CO2 and N-2 Adsorption in Nano-porous BEA Type Zeolite with Different Cations

Abstract

Adsorption of CO2 and N-2 in nano-porous BEA having SiO2/Al2O3 of 25, BEA(25), was studied by combining equilibrium adsorption measurements and Grand Canonical Monte Carlo (GCMC) simulation. CO2 sorption is observed to show higher sorption capacity than N-2 in all cation exchanged zeolite samples. On exchanging the BEA(25) with various cations, Li+, K+, Cs+, Ca2+, Sr2+, and Ba2+, the adsorption capacity of CO2 and N-2 are increased in these type of zeolites. The isosteric heat of sorption data shows stronger interactions of both CO2 and N-2 molecules in BEA(25) on decreasing size of the extra-framework cation. Simulation of the CO2 and N-2 sorption in cation exchanged BEA(25) clearly shows that the adsorbed CO2 and N-2 molecules sit closely to the extra-framework cations accessible through the large cage. Simulation of adsorption isotherms and heats of adsorption of CO2 and N-2 in cation exchanged BEA(25) match reasonably well with the experimental results. (C) 2015 Elsevier Ltd. All rights reserved.