Modeling of non-ideal binary adsorption

At non-ideal multicomponent adsorption systems, adsorbed phase behavior is not well predicted by ideal adsorption solution theory (IAST). At these systems, real adsorption solution theory (RAST) can present more accurate predictions by introducing adsorbed phase activity coefficients provided that they are obtained with a suitable thermodynamic model. In this paper, RAST with Wilson equation was develop for modeling of adsorbed phase behavior. In obtaining activity coefficients of components, Gibbs–Duhem equation at only constant temperature was utilized because the spreading pressure varies at the adsorption process. According to the results of the systems investigated, it was revealed that the model reduces the average prediction errors to about 10% (in worst case) while it is more than 50% by IAST.