A Novel Model for Correlation and Predication of the Equilibrium CO₂ Solubility in Seven Tertiary Solvents

In this work, the novel tertiary amines, 4-(dimethylamino)-2-butanol (DMAB), 4-(dipropylamino)-2-butanol (DPAB), 4-((2-hydroxyethyl)(methyl)amino)-2-butanol (HEMAB) and 4-((2-hydroxyethyl)(ethyl)amino)-2-butanol (HEEAB), 1-(2-Hydroxyethyl)-piperidine (1-(2-HE)PP), 1-(2-Hydroxyethyl)pyrrolidine (1-(2-HE)PRLD) and 3-diethylamino-1,2-propanediol (DE-1,2-PD) were synthesized or screened to reduce energy requirement of PCC to 2.0GJ/ton CO₂. The CO2 equilibrium solubility of those solvents were provided. A new K₂ correlation model, Liu et al. model, was also developed to correlate and predict the CO₂ equilibrium solubility in those new amines solution. It was found that the new model could fit the CO₂ equilibrium solubility in those newly solution with absolute average deviations (ADDs) for DMAB, DPAB, HEMAB, HEEAB, 1-(2-HE)PP, 1-(2-HE)PRLD, DE-1,2-PD of 5.4%, 24.7%, 8.3%, 4.2%, 1.7%, 4.1%, and 2.3%, respectively.