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Abstract
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This study focused on comprehensive synthesis and analysis
for CO2 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 CO2 /N2 system was considered for the investigation ofadsorption and separation of CO2. The adsorption equilibrium data of CO2
and N2 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 CO2 and N2 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 CO2 over N2 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 CO2 in practical applications.
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