Reaction kinetics of some important alkanolamines with carbon dioxide in aqueous solutions using stopped flow technique

Abstract

The kinetics of the reactions between aqueous solutions of carbon dioxide and Aminomethylpropanol (AMP), Aminobutanol (AB), Aminopropanol (AP), Diethanolamine (DEA) and Ethanolamine (MEA) were investigated over a temperature range of 293-313 K and different amine concentrations using a stopped flow technique. It was found that at each temperature, MEA reacts faster than AB, which in turn, reacts faster than AMP and DEA respectively. Reactions of MEA, DEA and AB can be explained by the zwitterion mechanism. However, the reaction mechanism of the AMP, a hindered amine, is suggested to be similar to that for tertiary amines, but at a faster rate. The rate constants required to predict reaction rates of these amines with CO2 have been calculated and presented in this work.