Experimental and computational study on enhanced synergy in CO ₂ absorption kinetics of 3AP / DMEA water‐lean blends

Amine‐based water‐lean solvents serve as energy‐efficient absorbents for carbon dioxide (CO 2 ) capture but partially face the kinetic challenge of low reaction rates. In this study, stopped‐flow experiments were conducted to investigate the CO 2 absorption kinetics of 3‐Aminopropanol (3AP)‐N,N‐dimethylethanolamine (DMEA) blends. Results reveal that high‐concentration DMEA significantly boosts primary‐tertiary amine synergy, enabling “low‐water, high‐rate” absorption. MD simulations elucidated the mechanism: DMEA acts as a competitive proton acceptor, switching the zwitterion proton transfer pathway toward DMEA and weakening 3AP solvation, increasing free active 3AP. Ab initio molecular dynamics combined with density functional theory calculations further confirmed the enhanced synergy in ethanol is driven by preferential zwitterion proton transfer to DMEA. The proposed mechanism was validated by a kinetic model (AARD <6.00%). This work provides deep insights into primary‐tertiary amine synergy in water‐lean blends, guiding the development of high‐efficiency water‐lean CO 2 absorbents.