Study on CO2 adsorption performance of TEPA-functionalized adsorbents on different resin supports

Adsorbents prepared by impregnating tetraethylenepentamine (TEPA) into porous materials represent promising candidates for CO 2 capture from coal-fired flue gas. This study impregnated TEPA into four types of resins to investigate the influence of different resins on the CO 2 adsorption performance of TEPA-resin adsorbents. Experimental data indicate that the CO 2 adsorption performance of TEPA-resin composites follows the order: DA201D > XAD-2 > ADS-17 > AB-8, where TEPA@DA201D exhibited the highest adsorption capacity of 3.46 mmol/g under 35℃ and 15 vol% CO 2 conditions. TEPA@DA201D possesses a hierarchical mesoporous structure with a high pore volume (1.084 cm 3 /g) and large average pore diameter (20.0 nm), which synergistically enhances CO 2 adsorption by promoting CO 2 diffusion and improving the dispersion of active sites. Simultaneously, SEM images reveal that DA201D exhibits the least aggregation of surface amine groups compared to other adsorbents. Different adsorption kinetic models reveal that its adsorption behavior conforms to the Avrami model, primarily governed by the synergistic effects of physical and chemical adsorption. The rate-limiting steps for CO 2 adsorption by the TEPA@DA201D adsorbent are mainly membrane diffusion and intra-particle diffusion at different temperatures. Furthermore, multifactorial interaction analysis indicates that adsorption temperature, gas flow rate, and CO 2 concentration independently regulate the adsorption capacity of TEPA@DA201D. This work provides theoretical guidance and design strategies for improving the design and performance of organic amine-modified resin-based adsorbents.