Effect of structural properties of amine functionalized zeolite adsorbents support on CO2 adsorption performance

Abstract

In order to investigate the influence of the structural properties of amine functionalized zeolite adsorbents support on their CO2 adsorption performance and further explore effective methods for low-cost preparation of efficient CO2 adsorbents, different post-treatment methods were used to modify the pore structure of MCM–41 zeolite, and tetra-ethylenepentamine (TEPA) was loaded onto these zeolites to prepare amine functionalized adsorbents. The properties of the zeolite support were characterized using the methods such as N2 adsorption-desorption experiment, scanning electron microscopy, X-ray diffraction and flourier transform infrared spectroscopy. The adsorption performance of the adsorbent was evaluated using a thermogravimetric analyzer (TGA). The structural properties of the support, effects of active amine loading and adsorption temperature on CO2 adsorption performance were systematically studied, and the adsorption kinetics and activation energy of the adsorbent was calculated. Finally, the stability of the adsorbent was evaluated through cyclic adsorption and desorption experiments. The results indicate that by designing the structure of the support reasonably, the CO2 adsorption performance of adsorbents based on different adsorption principles can be effectively improved. The microporous zeolites are more favorable for the physisorption process, while the hierarchical mesoporous zeolites with a wide pore size distribution exhibit a better chemisorption performance than the microporous zeolites after loading with active amines. At 80 ℃ and 15% CO2, the maximum adsorption capacity of the adsorbent (M–N−T60) which modified in structure and loaded with TEPA reached 4.04 mmol/g. After 10 adsorption and desorption cycles, the adsorption capacity of M–N−T60 only decreased by 8.4%, demonstrating good cycling stability, indicating that the M–N−T60 is a potential material for capturing CO2 from flue gas.

Keywords

• co2 capture
• amine functionalized adsorbent
• mcm–41 zeolite
• post processing modification
• cycling stability