Absorption of CO2 into aqueous mixtures of glycerol and monoethanolamine

Abstract The solubility of CO 2 in aqueous solutions 30 wt% monoethanolamine (MEA) mixed with various glycerol concentrations was measured. The CO 2 absorption was performed at three different temperatures (313, 323, and 333 K), and pressures ranging from 500 to 1500 kPa with concentrations of glycerol in the mixture varying from 0 to 20 wt%. Correlations of solubility as a function of CO 2 partial pressure were obtained with deviation of less than 2% over the pressure range investigated. The CO 2 loading at various temperatures, pressures, and concentrations showed an agreement to the general trend of absorption (i.e., increasing the equilibrium loading with decreasing the temperature and increasing the pressure). The solubility of the MEA solution increased by adding glycerol up to a level of 10% at lower pressures. The findings showed that 5 wt% glycerol in the mixture was the concentration that yielded the optimum CO 2 solubility as it could increase the CO 2 solubility of MEA at low pressures and approximately maintain its capture performance at high pressures. It confirmed that the solvent is suitable for the absorption of CO 2 under low pressures (below 1000 kPa) and can be applied in low-pressure CO 2 absorption processes such as post-combustion CO 2 capture.