Study on the effect of operating parameters towards CO2 absorption behavior of choline chloride - Monoethanolamine deep eutectic solvent and its aqueous solutions

In this study, the effect of absorption pressure and temperature towards the CO2 absorption capacity and rate of choline chloride monoethanol amine deep eutectic solvent (ChCl-MEA DES) was evaluated. Water mixing into ChCl-MEA DES was also examined as a method to improve CO2 absorption behavior. Equilibrium experiments were done in a batch reactor and the data was analyzed using response surface methodology (RSM). Results suggested that the dominant mode of CO2 absorption by ChCl-MEA DES was physical absorption. The maximum capacity of CO2 absorption obtained in this study was 0.379 mol-CO2/mol-DES from absorption at (10 bar, 40 degrees C) using DES with 50 %v water. Water mixing up to 50 %v was found to nearly double the CO2 absorption capacity of ChCl-MEA DES compared to neat DES. Study into CO2 absorption rate by ChCl-MEA DES found that it is mainly influenced positively by pressure and water content, while not significantly influenced by temperature. CO2 absorption rate of ChCl-MEA DES with 50 %v water was found to be on average twice of that of neat DES. It was also found that water content up to 50 %v does not change the mechanism of CO2 absorption by ChCl-MEA DES.