High-pressure measurement and thermodynamic modeling of the carbon dioxide solubility in the aqueous 2-((2-aminoethyl)-amino)-ethanol + sulfolane system at different temperatures

Abstract

In this work, we presented the set of the experimental VLE data of solubility of carbon dioxide in the blend of 2-((2-Aminoethyl) amino) ethanol (AEEA) and sulfolane utilizing a quasi-static high-pressure equilibrium cell. We performed the measurements under isothermal conditions at temperatures of 313.15, 328.15 and, 343.15 K, and up to the maximum pressure of 5500 kPa. We used the various solvent mass compositions of (30–20–50), (30–10–60), (20–20–60), (20–10–70), (10–20–70), (10–10–80) wt% for the AEEA + sulfolane + H2O system. It was found that the CO2 loading in the solvent significantly enhanced by decreasing temperature and increasing pressure. Besides, CO2 solubility was improved by increasing both of sulfolane and AEEA concentration. Nevertheless, at the low CO2 loading region, the acid gas loading was reduced through enhancing the sulfolane concentration. Moreover, it was shown that an aqueous mixture of AEEA + sulfolane has a better performance than an aqueous blend of MDEA + sulfolane for CO2 removal. Furthermore, to model the CO2 solubility in the mixtures, a robust thermodynamics model based on the E-NRTL function was employed to correlate and predict the partial pressure of CO2 against its loading. The reasonable agreement between the calculated and experimental results demonstrated the high accuracy of the present thermodynamic modeling.