Study on CO 2 Mass Transfer and Kinetics of N -Aminoethyl Piperazine Aqueous Solution in a Wetted Wall Column

Amine-based absorption is a promising CCUS technology. Primary/secondary amines offer fast CO 2 absorption but low capacity, while tertiary amines have high capacity but slow kinetics. 1-(2-Aminoethyl) piperazine (AEP), containing both primary/secondary and tertiary N, can combine a high rate with high capacity. In this work, the total mass transfer coefficient ( K G ) as well as first-order ( k 0 ) and second-order ( k 2 ) kinetic constants of CO 2 absorption in aqueous AEP was measured in a wetted-wall column under varying conditions (temperature, CO 2 loading, gas/liquid flow rate, and concentration). Temperature (30–80 °C) showed an initial increase and then a decrease in K G, while CO 2 loading negatively correlated with K G . Gas flow rate and temperature mainly influenced the gas-phase mass transfer coefficient. A mass transfer model and an empirical kinetic equation were established using solubility data and double-film theory. This study provides essential physicochemical and kinetic data for AEP, supporting the design of efficient amine-based CO 2 capture processes.