Kinetics of the reactive absorption of carbon dioxide in high CO 2-loaded, concentrated aqueous monoethanolamine solutions

Abstract

The kinetics of the reaction between carbon dioxide and high CO 2-loaded, concentrated aqueous solutions of monoethanolamine (MEA) were investigated over the temperature range from 293 to 333 K , MEA concentration range from 3 to 9M, and CO 2 loading from ∼0.1 to 0.49 mol/mol. The experimental kinetic data were obtained in a laminar jet absorber at various contact-times between gas and liquid. The obtained experimental data were interpreted with the aid of a numerically solved absorption-rate/kinetic model. The results showed that only the termolecular mechanism of Crooks and Donnellan could be used to explain all observed kinetic phenomena. These results allowed us to develop a new termolecular-kinetics model for CO 2 reaction with MEA solutions, which proved to be better than previously published kinetic models. The model was comprehensive enough to describe for the first time the absorption of CO 2 in highly concentrated and high CO 2-loaded aqueous MEA solutions for a wide temperature range.