Adsorption of gases on 4A synthetic zeolite

Equilibrium data are presented for the adsorption of permanent gases and C 1 and C 2 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, O 2 , CH 4 , and C 2 H 6 were the least strongly adsorbed, followed in order of increasing strength by N 2 , CO, CO 2 , and C 2 H 2 . Ethylene was strongly but anomalously adsorbed. For the gases studied, the quadrupole moment seems to be the principal factor determining strong adsorption.