New model that describes adsorption of laterally interacting gas mixtures on random heterogeneous surfaces. 1. Parametric study and correlation with binary data

Analytic expressions for the adsorption of a binary gas mixture that laterally interacts on a random heterogeneous surface are developed. The lateral interactions are of the Bragg-Williams type, and the surface heterogeneity is modeled via a random distribution of sites described by a uniform distribution of Henry's law constants. A parametric study shows that complex phase behavior can be predicted with this model, including azeotropes and sigmoidal-shaped x-y diagrams. This model is also successfully correlated with binary data from the literature with average relative errors of less than 10% for both single-component and binary adsorption data.