In this study seven adsorption azeotropes involving binary systems and zeolite-based adsorbents were systematically investigated. Pure component isotherms and mixed-gas adsorption data were taken from published literature except for the benzene–propene system on silicalite, which is newly presented in this work using molecular simulations. Experimental adsorbed phase composition and total amount adsorbed of the azeotropic systems were compared with the predictions of several models including: the ideal adsorbed solution theory (IAST), the heterogeneous ideal adsorbed solution theory (HIAST) and the real adsorbed solution theory (RAST) coupled with the 1-parameter Margules (1-Margules) and the van Laar equations. In the latter two models an additional loading parameter was incorporated in the expression of the excess Gibbs energy to account for the reduced grand potential dependency of the activity coefficients in the adsorbed phase. It was found that the HIAST and RAST–1-Margules models were able to predict the azeotropic behaviour of some systems with good accuracy. However, only the RAST–van Laar model consistently showed an average relative deviation below 3% compared to experimental data for both the adsorbed phase composition and the total amount adsorbed across the systems. This modified van Laar equation is therefore preferable in those engineering applications when the location of adsorption azeotropes is required with great accuracy and when there is lack of detailed characterization of the adsorbent that is needed to carry out molecular simulations.

在这项研究中，系统地研究了涉及二元系统和沸石基吸附剂的七种吸附共沸物。纯组分等温线和混合气体吸附数据取自已发表的文献，但硅沸石上的苯 - 丙烯系统除外，这是本工作中使用分子模拟新提出的。将共沸体系的实验吸附相组成和总吸附量与几种模型的预测进行了比较，包括：理想吸附溶液理论（IAST）、非均相理想吸附溶液理论（HIAST）和真实吸附溶液理论（RAST）耦合使用 1 参数 Margules (1-Margules) 和 van Laar 方程。在后两个模型中，额外的加载参数被纳入过量吉布斯能量的表达式中，以解释吸附相中活度系数的大电位依赖性降低。发现 HIAST 和 RAST-1-Margules 模型能够以良好的精度预测某些系统的共沸行为。然而，与吸附相组成和系统吸附总量的实验数据相比，只有 RAST-van Laar 模型始终显示出低于 3% 的平均相对偏差。