Investigation of CO₂ Regeneration in Single and Blended Amine Solvents with and without Catalyst

Various single and blended amines (namely, MEA(monoethanolamine), MEA-DEEA (2-diethylamino ethanol), MEA-MDEA (methyldiethanolamine), MEA-1DMA2P (1-dimethylamino-2-propanol)) with three types of catalysts (H-ZSM-5, MCM-41 and SO42–/ZrO2) were studied to determine the respective roles of catalyst and solvent in heat duty and CO2 desorption rate with an initial CO2 loading of 0.5 mol CO2/mol amine at 371 K. The results show that performance of the three catalysts in all the four investigated aqueous solution systems followed the trend: H-ZSM-5 > MCM-41 > SO42–/ZrO2. These results highlight the fact that even though HZSM-5 has moderate acidic sites as compared to MCM-41 and SO42–/ZrO2, its large B/L acid sites ratio coupled with mesopore surface area had the best performance. Furthermore, based on this study, the blended system of aqueous 5 M MEA+1 M MDEA with H-ZSM-5 provided the best approach for solution regeneration because the strong electron withdrawing chemical structure of MDEA.