ROLE OF ADSORBENT HETEROGENEITY ON MIXED GAS-ADSORPTION

A family of simple, analytic, and thermodynamically consistent correlations is developed to describe adsorption of pure and multicomponent gases on heterogeneous adsorbents. The model is based on the assumptions that the adsorbent can be described by the conventional "patchwise homogeneous" framework of heterogeneity with Langmuir adsorption model giving the local equilibria on a patch and that a distribution of Henry's law constants depict the energetic heterogeneity. A simple site energy matching formula based on coalescence of dimensionless cumulative distribution functions of the Henry's law constants of different gasses is used to connect the pure and mixed gas adsorption. The model is tested by using published experimental data for pure an binary gas adsorption. A parametric study of the model parameters is carried out to demonstrate the very significant role of adsorbent heterogeneity on mixed gas adsorption, including adsorption azeotropy.