ISOSTERIC HEATS OF MULTICOMPONENT GAS-ADSORPTION ON HETEROGENEOUS ADSORBENTS

Isosteric heats of adsorption of the components of a gas mixture on a heterogeneous adsorbent can be estimated from multicomponent adsorption isotherms by using thermodynamic relationships. It is shown by using the simplified Toth equation for heterogeneous binary-gas adsorption that the component isosteric heats of adsorption can be strong functions of specific loadings of the components. These functions are very different from the loading dependence of pure-gas isosteric heats. It is also shown that the degree of adsorbent heterogeneity very strongly influences the component isosteric heats. Analytical mixed-gas heterogeneous adsorption isotherms are preferred for calculating the mixed-gas isosteric heats.