Modeling of CO₂ equilibrium solubility in a novel 1-Diethylamino-2-Propanol Solvent

In this work, the equilibrium solubility of CO₂ in a 1-diethylamino-2-propanol (1DEA2P) solution was determined as a function of 1DEA2P concentration (over the range of 1–2 M), temperature (in the range of 298–333 K), and CO₂ partial pressure (in the range of 8–101 kPa). These experimental results were used to fit the present correlation for K₂ (Kent-Eisenberg model, Austgen model, and Li-Shen model). It was found that all of the models could represent the CO₂ equilibrium solubility in 1DEA2P solution with ADDs for Kent-Eisenberg model, Austgen model, and Li-Shen model of 6.3, 7.3, and 12.2%, respectively. A new K₂ correlation model, the Liu-Helei model, was also developed to predict the CO₂ equilibrium solubility in 1DEA2P solution with an excellent ADD of 3.4%. In addition, the heat of absorption of CO₂ in 1DEA2P solution estimated by using the Gibbs-Helmholtz equation was found to be −45.7 ± 3.7 kJ/mol. Information and guidelines about effectively using data for screened solvents is also provided based on the three absorption parameters: CO₂ equilibrium solubility, second order reaction constant (k₂), and CO₂ absorption heat.