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To implement an experimental study of CH 4 / N 2 adsorption on Zeochem Co. zeolite 13X, a volumetric apparatus was utilized. In this regard, pure adsorption isotherms were measured at different temperatures [(273, 283, 303, 323, and 343) K] and pressures up to 10 bar, while binary data were collected at (303 and 323) K and different pressures and bulk gas phase molar fractions. Integral and differential thermodynamic consistency tests (TCT) were performed to validate the collected data and certify accuracy of the measurements. To have a thermodynamic view over the investigated system, thermodynamic functions such as enthalpy, entropy, surface potential, and Gibbs free energy were estimated numerically. Besides, the measured pure isotherms were regressed using different isotherm equations and the regressed parameters were applied to different models based on the thermodynamic theory of solutions, i.e., ideal adsorbed solution theory (IAST), vacancy solution models (VSM), and Peng− Robinson two-dimensional equation of state (PR 2D-EOS). All the models were applied in the predictive scheme. Experimental and predicted adsorption data were compared through the appropriate phase diagrams. Almost all the models could predict binary adsorption behavior of CH 4 and N 2 over zeolite 13X.

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This study focused on comprehensive synthesis and analysis for CO 2 adsorption of the widely used zeolites 13X, 4A, 5A, and beta. Zeolites were synthesized utilizing the hydrothermal method. We paid special attention to the characterization of synthesized zeolites. The most common instrumental analysis techniques, including X-ray diffraction (XRD), scanning electron microscopy (SEM), the Brunauer−Emmett−Teller (BET) method, thermogravimetric analysis (TGA), differential thermal gravimetry (DTG), differential thermal analysis (DTA), and X-ray fluorescence (XRF), were utilized in this study. All results indicated the successful synthesis of these types of zeolites. The CO 2 /N 2 system was considered for the investigation of adsorption and separation of CO 2 . The adsorption equilibrium data of CO 2 and N 2 on pelletized zeolites were taken at temperatures of 283, 303, and 323 K and pressures up to 1.6 bar utilizing a volumetric method. The highest adsorption capacity was obtained for zeolite 13X and the lowest for zeolite beta. The Sips and Langmuir isotherm models were used for matching adsorption isotherm data. Experimental data showed the best correlation with the Sips model with six parameters. The isosteric heats of adsorption for CO 2 and N 2 on all the studied adsorbents were evaluated utilizing the pure adsorption isotherms data at studied temperatures by the Clausius−Clapeyron equation. Also, binary adsorption data and selectivities of CO 2 over N 2 on all adsorbents were determined by ideal adsorbed solution theory (IAST). It can be concluded from all the obtained results that the studied zeolites, especially zeolite 13X, can be promising adsorbents to capture CO 2 in practical applications.