The solubility of CO2 in aqueous 1,8-p-menthane-diamine (MDA) solution with substance concentrations of 0.625 and 1.25 mol center dot L (1) was measured at temperatures (313.15, 333.15 and 353.15) K with CO2 partial pressures ranging from (0.55 to 776.0) kPa and CO2 loading ranging from (0.120 to 1.97) mol CO2 per mol MDA. The gas solubility results are expressed as the partial pressure of CO2 (PCO2) against its mole ratio, i.e. alpha(CO2) (mol CO2 per mol MDA). The chemical absorption reaction and thermodynamic model have been proposed. The physicochemical Kent-Eisenberg model was used to correlate all the experimental results of the solubility of CO2 in the aqueous MDA solutions under investigation. The chemical equilibrium constants and model parameters were determined by fitting the VLE data. (C) 2013 Elsevier Ltd. All rights reserved.