Calculation of equilibrium solubility of carbon dioxide in aqueous mixtures of monoethanolamine with methyldiethanolamine

Li M.H. and Shen K.-P., 1993. Calculation of equilibrium solubility of carbon dioxide in aqueous mixtures of monoethanolamine with methyldiethanolamme. Fluid Phase Equilibria, 85: 129-140. The equilibrium solubility of carbon dioxide in aqueous mixtures of monoethanolamine (MEA) with methyldiethanolamine (MDEA) has been correlated on the basis of the model of Kent and Eisenberg. The chemical equilibrium constants involving alkanolamines are expressed as functions of temperature, amine concentration and carbon dioxide loading. The constants in the model were determined by fitting to the solubility data of carbon dioxide in aqueous MEA/MDEA solutions for temperatures ranging from 40 to 100°C and for partial pressures of carbon dioxide up to 2000 kPa. Satisfactory results were obtained for calculations of the solubility of carbon dioxide in aqueous MEA/MDEA solutions for the systems tested. When performing the solubility calculations for the systems which are not included in the database, the model predicts reasonably well the solubility of carbon dioxide in aqueous MEA/MDEA solutions.