Journal of Chemical and Engineering Data, Vol.64, No.6, 2368-2379, 2019
Physicochemical Properties of the System N,N-Dimethyl-dipropylene-diamino-triacetonediamine (EvA34), Water, and Carbon Dioxide for Reactive Absorption
Aqueous solutions of N,N-dimethyl-dipropylene-diamino-triacetonediamine (EvA34) are promising solvents for CO2 capture. Therefore, in the present work, a comprehensive experimental study was carried out to determine data on physicochemical properties of EvA34 and its mixtures with H2O and CO2. The liquid density and the dynamic viscosity were studied for pure EvA34, as well as for unloaded and CO2-loaded aqueous solutions of EvA34. The liquid heat capacity was studied for pure EvA34 and unloaded aqueous solutions of EvA34. Furthermore, data on the vapor pressure of pure EvA34 was recorded. The pH value was measured for unloaded and CO2-loaded aqueous solutions of EvA34, and the dissociation constants of EvA34 were determined from titration curves. Moreover, data on the solubility of CO2 in aqueous solutions of EvA34 and data on the CO2-containing species in the liquid phase of these solutions were recorded. Most of the new data were taken at temperatures between 293 and 393 K. The mass fraction of EvA34 in the unloaded aqueous solutions was either (w) over tilde (0)(EvA34) = 0.1 g/g or (w) over tilde (0)(EvA34) = 0.4 g/g. The CO2 loading was up to (alpha) over tilde (CO2) = 6.2 mol/mol. The new data were compared to corresponding data of two standard amines that are used for CO2 capture: monoethanolamine (MEA) and a blend of methyl-diethanolamine and piperazine (MDEA/PZ). The comparison revealed that EvA34 combines favorable properties of MEA and MDEA/PZ in one molecule.