Adsorption of gases on 4A synthetic zeolite

Abstract

Equilibrium data are presented for the adsorption of permanent gases and C1 and C2 hydrocarbons on Linde 4A synthetic zeolite from 50 °C down to the boiling point of the adsorbate or to a temperature at which the rate was very slow. The Freundlich equation often fits isotherms accurately; however, these linear logarithmic plots seem to be only portions of a more general non-linear relationship. Generalized Polanyi plots did not yield a unique characteristic curve for individual adsorbates at different temperatures nor for groups of adsorbates; nevertheless, these plots are useful in estimating the relative strength of adsorption of gases. Ar, O2, CH4, and C2H6 were the least strongly adsorbed, followed in order of increasing strength by N2, CO, CO2, and C2H2. Ethylene was strongly but anomalously adsorbed. For the gases studied, the quadrupole moment seems to be the principal factor determining strong adsorption.