Carbon dioxide absorption by aqueous mixtures of diisopropanolamine and triethanolamine

Aqueous secondary and tertiary alkanolamine mixtures are novel absorbents for carbon dioxide removal. This study evaluates the CO 2 absorption by aqueous mixtures of diisopropanolamine (DIPA) and triethanolamine (TEA) in a bubble column reactor considering the influence of the mixture composition, gas flow rate and time on the hydrodynamic parameters, reaction mechanism and mass transfer coefficient. The nuclear magnetic resonance spectroscopy (NMR) was performed to evaluate the possible synergic effects produced by the use of this alkanolamine mixture. The gas flow rates were 18, 30 y 40 L h −1 and the total concentration of the mixtures was 10% of total weight, varying the proportions of DIPA and TEA. The composition of the mixtures (corresponding to the 10% of amine)was varied over the entire composition range.