Correlating the physical solubility of CO2 in several amines to the concentrations of amine groups

In this study, the physical solubilities of CO2 in several amine solutions at different concentrations and pressures were determined using the nitrous oxide N2O analogy. The solubilities of N2O in four aqueous amine solutions, including Monoethanolamine (MEA), Diethanolamine (DEA), Diethylenetriamine (DETA), and Tetraethylenepentamine (TEPA) were determined experimentally at different concentrations and pressures ranging from 1 to 4 kmol/m3 and 101.3-405.3 kPa, respectively. The solubility of N2O and CO2 for a few amines were compared with data available in the literature. The experimental data agreed well with those published in the literature. The CO2 solubility values obtained experimentally as well as other values from the literature were correlated to the concentrations of the amino groups in the amine. The physical solubility of CO2 was found to be inversely proportional to the number of amino groups in the amine. The simple correlation can give reasonable predictions with an average error of less than 10% for CO2 solubility at 298 K and 101.3 kPa.