Absorption of Carbon Dioxide into Glycine Activated Methyldiethanolamine (MDEA) Comparing with Diethanolamine (DEA)

Abstract

It is widely accepted that increasing carbon dioxide (CO2) emissions to our atmosphere is the major contributor to global climate change, which pollutes environment. The chemical absorption using tertiary alkanolamines solution is one of most important method, which have been proposed and studied for the removal of carbon dioxide because the MDEA solvent has low cost, low corrosive tendencies, high stability, low viscosity, low tendency to foam, and low flammability, however it has low reaction rate. Therefore, we added glycine promoter to conventional solvents to increase the rate of the reaction because glycine is a primary amine compound which is reactive. Moreover, glycine has resistance to high temperatures; so, it will not easy to degrade making it not suitable for application in industry. The main purpose of this study was to provide reaction kinetics data of CO2 absorption into glycine promoted methyldiethanolamine (MDEA) by using laboratory scale wetted wall column equipment at the atmospheric pressure by varying temperature from 303.15 to 328.15 and glycine concentration from 1% to 3%, while the carbon dioxide absorption rate was measured by titration of liquid effluent. Based on the result of this study, we observed that by increasing temperature and concentration of glycine, the absorption rate of carbon dioxide in MDEA solution was increase. In addition, the reaction rate constant will be affected by the temperature and the concentration of promoter. The correlation of reaction rate constant (k glycine) was: k glycine = 5.3409E+13exp(-3251.9/T) with the activation energy for glycine promoter is 27.0363kJ/kmol, indicating it a very influencing, compared to diethanolamine (DEA).