Equilibrium solubility of CO2 in aqueous solutions of 1-amino-2-propanol as function of concentration, temperature, and pressure

Using a dynamic method with recirculation of the vapour phase, experimental values for the gas solubility of carbon dioxide in aqueous solutions of 1-amino-2-propanol (MIPA) were measured at T = (313.15 and 393.15) K, over the pressure range of (0.2 to 2436.4) kPa. The concentrations of the studied aqueous MIPA solutions were (0.20, 0.30, 0.40, and 0.50) mass fraction. The results of gas solubility are given as the partial pressure of CO2, pCO2pCO2, against its mole ratio, αCO2αCO2 (mol CO2 · mol−1 MIPA), and its mole fraction, xCO2xCO2. It is observed that the solubility of CO2 increases as the concentration of MIPA in solution increases, at a given temperature throughout the pressure range considered; also the solubility values increase, under constant temperature, as the pressure increases in the studied concentration range of MIPA.The physicochemical model of Kent and Eisenberg was used to correlate simultaneously all the experimental results of the solubility of CO2 in the studied aqueous solutions of MIPA. The model correlates satisfactorily the experimental results. The deviation for pressure was 96.9 kPa using 62 experimental solubility points.The solubility results of carbon dioxide presented in this work are compared with those reported in the literature for aqueous solutions of monoethanolamine (MEA), diethanolamine (DEA), diisopropanolamine (DIPA), and N-methyldiethanolamine (MDEA) and it is possible to conclude that the aqueous solutions of MIPA are an excellent alternative to use in gas purification processes, since the magnitude of the solubility results of MIPA solutions was found to be similar to that in aqueous solutions of MDEA, better than DEA and DIPA.

Research highlights
► Gas solubility of CO2 in aqueous solutions of 1-amino-2-propanol was measured.
► Solubility increases as pressure and concentration of 1-amino-2-propanol increase.
► The Kent–Eisenberg model was used to correlate all the experimental results.
► Aqueous solutions of MIPA are an excellent alternative to use in gas purification.