Physicochemical Properties of Aqueous Potassium Salts of Basic Amino Acids as Absorbents for CO2 Capture

Aqueous amino acid salt (AAS) solutions could be attractive absorbents for CO2 removal from flue gases. Density, viscosity, and solubility of N2O in aqueous potassium salts of lysine, histidine, and arginine were measured over the temperature range from (293 to 353) K and molality concentration range from (0.26 to 3.6) mol·kg–1. Experimental results were correlated well with empirical correlations. The ion specific parameters (hAA–), based on the Weisenberger and Schumpe model, were fitted using the solubility data of N2O in the aforementioned AAS systems, valid up to 328 K. The models using temperature dependence of hAA– predict well within 2.5% AAD. The physical solubility of CO2 in the aqueous AAS solutions was also estimated.