Prediction of the adsorption equilibrium of mixtures composed of supercritical gases

A new model was proposed to predict the adsorption equilibrium of mixtures composed of supercritical gases. The adsorbed phase was visualized as a two-dimensional nonideal compressed gas. Pore size distribution was used to describe the energetic heterogeneity of the surface, and the two-dimensional virial equation was used as the local adsorption isotherm. The new model obtained is thermodynamically rigorous because it reduces to Henry's law as pressure approaches zero. The prediction performance of the new model was verified and compared with other models using the experimental data of a ternary mixture of CH₄/N₂/H₂ and two binary mixtures of CH₄/C₂H₄ and CH₄/N₂. Better performance was shown for all systems tested.