Experimental studies on mass transfer performance for CO2 absorption into aqueous N,N-dimethylethanolamine (DMEA) based solutions in a PTFE hollow fiber membrane contactor

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.