Insights into CO₂ adsorption on zeolite ZSM-5: an experimental and advanced modeling approach

The aim of this study was to investigate CO₂ adsorption on ZSM-5 zeolite. The adsorbent was characterized using X-ray diffraction (XRD), nitrogen adsorption-desorption isotherms, and scanning electron microscopy (SEM). The correlation coefficients (R²) obtained from the isotherm models indicate that the classical Langmuir model provides a good fit to the experimental data across different temperatures. In addition, the physicochemical parameters of the advanced multilayer model were examined in detail. Key isotherm parameters, including the number of CO₂ molecules per site (n), receptor site density (Dm), and energy parameters (ΔE₁ and ΔE₂), were also analyzed. The results suggest that CO₂ adsorption on ZSM-5 is spontaneous, exothermic, and governed by physisorption. Overall, the model outcomes can be applied to the design and optimization of a pilot-scale CO₂ adsorption system.