Kinetics study and simulation of CO2 absorption into mixed aqueous solutions of methyldiethanolamine and hexylamine

This study investigated kinetics of CO2 absorption into mixed methyldiethanolamine (MDEA) and hexylamine (HA) solutions in a Lewis cell reactor. The experiments were conducted in the temperatures 298, 313 and 333 K with mass concentrations MDEA 37 wt.% + HA 3 wt.%, MDEA 35 wt.% + HA 5 wt.% and MDEA 33 wt.% + HA 7 wt.%. Our results showed that adding a small amount of hexylamine enhances the kinetics of CO2 absorption and that the kinetics of CO2 absorption with aqueous MDEA 37 wt.% + HA 3 wt.% is pseudo first order regime with reduced activation energy compared to that of MDEA 40 wt.%. The absorption/regeneration system was simulated using Aspen plus™ software for the treatment of gas streams from cement plant in a post-combustion process. The analysis of our results established that blended solvent MDEA 37 wt.% + HA 3 wt.% gives lower energy consumption than that of MDEA 40 wt.%.