Kinetics of CO2 with a sterically hindered amine, 2-amino-2-methyl-1,3-propanediol (AMPD), in aqueous solutions were studied at temperatures of 303, 313, and 318 K and over the concentration ranging from 5 to 25 wt% AMPD using a wetted-wall column absorber. The N2O analogy was applied to estimate the physicochemical properties such as Henry's law constant and diffusivity of CO2 in amine solutions. The measured diffusion coefficients of N2O in aqueous AMPD solutions were correlated using a modified Stokes-Einstein equation. On the basis of the zwitterion mechanism, the zwitterion deprotonation and second-order rate constants were calculated and presented at each experimental condition. The second-order rate constants, k2, were found to be 382, 665, and 977 m3 kmol-1 s-1 at 303, 313, and 318 K, respectively. The activation energy for the reaction of CO2 with AMPD was calculated to be 38.3 kJ mol-1 with an absolute error of 3%.
ASJC Scopus subject areas
- Chemical Engineering(all)
- Industrial and Manufacturing Engineering