Application of ideal adsorbed solution theory (IAST) in the prediction of mixed-gas equilibria

Abstract Ni-gallate demonstrated notable CO 2 adsorption compared to CH 4 , showcasing its significance in the context of CO 2 /CH 4 separation. However, there have been no studies in predicting mixed-gas equilibria using the ideal adsorbed solution theory (IAST) approach for various CO 2 /CH 4 compositions. Therefore, the reported unary adsorption isotherms of CO 2 and CH 4 were fitted with models provided in Python package, in which Langmuir model demonstrated the lowest root mean square error (RMSE) with the most applicable parameter values. The prediction of mixed-gas equilibria was computed by varying CO 2 /CH 4 compositions at three different temperatures. The prediction of mixed-gas equilibria exhibited lower loadings compared to the reported unary adsorption isotherms of CO 2 and CH 4 due to the competitive adsorption. Nevertheless, the IAST selectivity values proposed that Ni-gallate prone to adsorb CO 2 over CH 4 and this is essential for CO 2 /CH 4 separation process. Therefore, Ni-gallate can be suggested as a promising alternative adsorbent in separation of CO 2 /CH 4 mixture.