Enhanced CO2 desorption rate for rich amine solution regeneration over hierarchical HZSM-5 catalyst

High energy consumption during the carbon dioxide (CO 2 ) desorption process in amine-based CO 2 capture technology is a crucial hindrance to achieving carbon neutrality. HZSM-5 is one of the most widely reported solid acid catalysts used in primary amine regeneration. This work compared a series of HZSM-5 zeolites with different Si/Al ratios in terms of CO 2 desorption performance. To further enhance catalytic activity, hierarchical HZSM-5 was synthesized by the dealumination and desilication re-assembly method with different acid and alkali concentrations. The experimental results suggested that desilication by modification in sodium hydroxide resulted in a significant improvement of mesoporous surface area. The NaOH-0.4 catalyst could improve the amount of desorbed CO 2 by 40.3% and decrease the relative heat duty by 28.5%. And the cyclic tests revealed that catalytic activity was well preserved in the recycling process. Moreover, the structure and acidity of modification samples were characterized by X-Ray diffraction (XRD), Fourier transforms infrared (FT-IR), Nitrogen adsorption–desorption experiment, temperature programmed desorption of ammonia (NH 3 -TPD), Pyridine-adsorption infrared spectroscopy (Py-IR), and scanning electron microscopy (SEM). The characterization results suggested that the synergistic effect of larger mesoporous surface area and total acid sites was important to enhance catalytic CO 2 desorption performance. These results showed a new understanding of catalyst design for CO 2 capture technology by modifying the structure of the catalyst support.