Experimental study of the kinetics of the homogenous reaction of CO2 into a novel aqueous 3-diethylamino-1,2-propanediol solution using the stopped-flow technique

In this work, the stopped-flow technique was used to determine the kinetic parameters in terms of pseudo first-order rate constants (k(0)) for homogenous reaction of CO2 into aqueous 3-diethylamino-1,2-propanediol (DEA-1,2-PD) solutions as temperature ranged from 293 to 313 K and amine concentrations ranged from 0.20 kmol/m(3) to 1.00 kmol/m(3). It was found that k(0) increased with increasing amine concentration and temperature. Both the base-catalyzed hydration and the termolecular models were applied to interpret the experimental data. The results showed that the predicted CO2 absorption rates exhibited good agreement with experimental data with an absolute average deviation (AAD) of 5.7% and 3.8% with respect to base-catalyzed hydration and the termolecular model, respectively. Furthermore, the pKa of DEA-1, 2-PD was experimentally determined over the temperature range from 298 to 318 K. The relationship between experimentally measured second-order reaction rate constants (k(2)) and pKa was correlated using the Bronsted relationship. The results suggest that the Bronsted relationship for DEA-1,2-PD developed in this work can predict the reaction rate constant very well with an AAD of 0.8%. (C) 2015 Elsevier B.V. All rights reserved.