where q sat j and K j (T ) are the saturation capacity and equilibrium parameter associated with site j, respectively. The S-site Langmuir model that achieved the lowest RMSE was selected to represent the simulated isotherms, as shown in Figure . The equilibrium parameters K j (T ) can be modelled interchangeably by the Arrhenius and Van't Hoff 71 equations by expressing the pre-exponential factor of the former as the temperature-independent term of the latter, as in b = exp (∆S/R). The resulting analytical expressions for the adsorption as a function of pressure and temperature were input to the process-level model equations.