BET model in its original or refined form (GAB) is widely used for studying the multilayer sorption of pure gases and vapors on the different solids. In this study, the BET model was theoretically extended for the prediction of gas mixtures sorption on the solids and the details of the model derivation with related assumptions were presented. Then, for better prediction, the extended GAB model which is a modified form of BET model was derived from the extended BET model. In order to check the validity of the proposed model, predictions of the extended GAB model were compared to the sorption data of several gas –solid systems including the light hydrocarbons, CO₂ and N₂ gases on different types of activated carbon and silica gel from literature. Also, the predictions of IAST and EL models were compared to the results of the model and R-squared for all the models were reported. The extended model predicted adsorption behavior of gas mixtures on different solids accurately. Thus, this model is a simple and useful tool to raise our knowledge with respect to the physical sorption of gas mixtures on different solids.

原始或精炼形式的BET模型（GAB）被广泛用于研究纯气体和蒸气在不同固体上的多层吸附。在这项研究中，从理论上扩展了BET模型，以预测混合气体在固体上的吸附，并给出了有关模型推导的细节和相关假设。然后，为了更好的预测，从扩展BET模型导出了扩展GAB模型，该模型是BET模型的改进形式。为了检验所提出模型的有效性，将扩展GAB模型的预测结果与包括轻烃，CO ₂和N ₂在内的多种气固系统的吸附数据进行了比较。文献中介绍了在不同类型的活性炭和硅胶上的气体 此外，将IAST和EL模型的预测与模型结果进行了比较，并报告了所有模型的R平方。扩展模型预测了混合气体在不同固体上的吸附行为。因此，该模型是一种简单而有用的工具，可以提高我们对混合气体在不同固体上的物理吸附的认识。