Regulation of water and sulfur resistance and study of carbon dioxide adsorption properties on FAU zeolites

CO 2 capture from blast furnace gas is of great significance for carbon reduction. 13X zeolites are frequently employed as CO 2 adsorbents. Nevertheless, their large-scale utilisation in industrial applications is impeded by the presence of H 2 O and H 2 S in blast furnace gas. To develop CO 2 adsorbents suitable for carbon capture from blast furnace gas, a series of Faujasite (FAU) zeolites were prepared in this study by modulating Si/Al. The findings revealed that the separation coefficients of CO 2 /N 2 and CO 2 /CO increased by 72 % and 144 %, respectively, and that the H 2 O adsorption decreased by 23 % when Si/Al was increased from 1.45 to 2.93. Furthermore, breakthrough experiments demonstrated that enhancing the Si/Al ratio of FAU zeolite can effectively reduce the dynamic adsorption capacity of H 2 O and H 2 S. Physicochemical characterizations of the zeolite before and after H 2 S adsorption were performed: CO 2 and N 2 adsorption isotherms, thermogravimetry, In-situ FT-IR and XPS. The present study investigates the effect of H 2 S adsorption on zeolites with varying Si/Al ratios. When combined with DFT calculations, the results demonstrate that the elevated Si/Al ratio of the zeolite results in a significant increase in sulfur resistance and easier deposition of H 2 S in the form of sulfate on the zeolite surface. It indicates that the modulation of Si/Al ratio is an effective method to improve the water and sulfur resistance of zeolites, and provides core material support for the practical application of large-scale carbon capture technology for blast furnace gas.