The challenge for the carbon dioxide (CO 2 ) capture by using amine solution is the huge energy cost in solvent regeneration process, this work combined the advantages of three conventional amines, monoethanolamine (MEA), 1-Dimethylamino-2-propanol (1DMA2P), and piperazine (PZ) to formulate an effective trio-amine blend to capture CO 2 , and the results demonstrate that the blends could reduce the energy consumption by 29.4–55.4%, increase the average desorption rate by 60–140%, and increase the cyclic capacity by 40–120%, relative to 5 M MEA solution. Through analysis the regeneration mechanism in detail, it is found that more proton provider in the trio-amine blends could help to reduce the energy consumption by lower the reaction activation energy in the deprotonation process of the protonated amines. Finally compared to the reported amine systems in considering of the energy cost, it is found that the MEA-1DMA2P-PZ could be a potential candidate for capturing CO 2 in industrial.
CO 2 absorption performance for various blended N ,N- dimethylethanolamine (DMEA) solutions in the presence of absorption promoters including Monoethanolamine (MEA), Piperazine (PZ), 2-(Ethylamino)ethanol (EAE), 2-(Methylamino)ethanol (MAE) and 2-Amino-2-methyl-1-propanol (AMP) was investigated in terms of CO 2 absorption flux by using a polytetrafluoroethylene (PTFE) hollow fiber membrane contactor. The experimental results show that the CO 2 absorption flux increases with a reasonable increase in liquid velocity, liquid temperature and total amine concentration. Also, the CO 2 absorption flux can increase by increasing gas velocity, CO 2 partial pressure but decrease with the increased lean CO 2 loading. In addition, it can be found that all of the investigated activated amines can improve the CO 2 absorption flux of aqueous DMEA solution. For fresh amine solution, the order of CO 2 absorption flux for the investigated amine blends can be ranked as: DMEA < DMEA + AMP < DMEA + MEA < DMEA + EAE < DMEA + MAE < DMEA + PZ. By contrast, for the amine solution with CO 2 loading of over 0.3 mol/mol, the order has also changed accordingly and can be ranked as: DMEA < DMEA + AMP < DMEA + EAE < DMEA + MAE < DMEA + MEA < DMEA + PZ. The DMEA + PZ mixture presents a significant improvement up to 52.44% in CO 2 absorption flux compared to that of single DMEA solution, and can be considered as a promising alternative for CO 2 capture.