Development of a pentaethylenehexamine-modified solid support adsorbent for CO2 capture from model flue gas

A novel solid support adsorbent for CO2 capture was developed by loading pentaethylenehexamine (PEHA) on commercially available mesoporous molecular sieve MCM-41 using wet impregnation method. MCM-41 samples before and after PEHA loading were characterized by X-ray powder diffraction, N2 adsorption/desorption, thermal gravimetric analysis and scanning electron microscope to investigate the textural and thermo-physical properties. CO2 adsorption performance was evaluated in a fixed bed adsorption system. Results indicated that the structure of MCM-41 was preserved after loading PEHA. Surface area and total pore volume of PEHA loaded MCM-41 decreased with the increase of loading. The working adsorption capacity of CO2 could be significantly improved at 60% of PEHA loading and 75 °C. The effect of the height of adsorbent bed was investigated and the best working adsorption capacity for MCM-41-PEHA-60 reached 165 mg·(g adsorbent)− 1 at 75 °C. Adsorption/desorption circle showed that the CO2 working adsorption capacity of MCM-41-PEHA kept stable.

Graphical AbstractA novel amine-impregnated support adsorbent MCM-41-PEHA was developed. Effects of adsorption temperature, PEHA loading, and regenerability on CO2 adsorption performance were examined. The effect of the height of adsorbent bed on CO2 adsorption in the fixed-bed adsorption system was also investigated. The characterization results indicate that the structure of MCM-41 is preserved after PEHA loading. The effect of adsorption temperature can be explained reasonably by using the two amine-layer adsorption theory. The height of adsorbent bed is an important parameter for practical application of MCM-41-PEHA adsorbent.Figure optionsDownload full-size imageDownload as PowerPoint slide