Exploring behavior of Clinoptilolite@Graphene oxide compositeas a novel adsorbent for CO₂ capture

Graphene oxide is an ideal base for solid adsorbents to capture CO₂. In this study, two materials, Clinoptilolite and Graphene oxide (GO), were used to prepare Clin@GO by autoclave at constant temperature and pressure. The response surface methodology based on the Box-Behnken design was applied to predict maximum adsorption capacity under optimum conditions. The highest adsorption capacity was 9 mmol/g achieved at 30 °C, 3.09 bar, and 0.25 g of adsorbent weight. The results of the isotherm study reveal that the Sips model has a high value of R². The Elovich kinetic model can describe experimental data showing the adsorption process on heterogeneous surfaces. The thermodynamic study results proved that the CO₂ adsorption process by Clin@GO is a physisorption and exothermic process. The mass transfer study disclosed that the mass transfer coefficient, diffusion coefficient, and mass flux values for CO₂ molecules as a gas phase in the single-component system are 0.9249 m/s, 0.00082 m²/s, and 0.00042 mol/m s, respectively.