Characterization of potassium glycinate for carbon dioxide absorption purposes

Abstract

Aqueous solutions of potassium glycinate were characterized for carbon dioxide absorption purposes. Density and viscosity of these solutions, with concentrations ranging from 0.1 to 3 M, were determined at temperatures from 293 to 313 K. Diffusivity of CO2 in solution was estimated applying the modified Stokes-Einstein relation. Solubilities of N2O at the same temperatures and concentrations were measured and the ion specific parameter based on Schumpe's model was determined for the glycinate anion; the solubilities of CO2 in these solutions were then computed. The reaction kinetics of CO2 in the aqueous solution of potassium glycinate was determined at 293, 298 and 303 K using a stirred cell reactor. The results were interpreted using the DeCoursey equation for the calculation of the enhancement factor. The rate of absorption as a function of the temperature and solution concentration for the conditions studied was found to be given by the following expression: -r(CO2) = 2.42 x 10(16) exp (-8544/T) exp(0.44C(S))CSCCO2.