Estimation of Normal Boiling Temperatures, Critical Properties, and Acentric Factors of Deep Eutectic Solvents

Deep eutectic solvents (DESs) are novel solvents that have shown the ability to capture carbon dioxide from flue gases. Thermodynamic modeling is needed to validate the experimental vapor–liquid equilibria (VLE) of the CO2–DES systems. To establish thermodynamic models of these solvents, their critical properties must be estimated. In the present study, a combination of the modified Lydersen–Joback–Reid (LJR) method and the Lee–Kesler mixing rules has been applied to estimate the critical properties of 39 different DESs. Normal boiling temperatures and acentric factors have also been determined. The accuracy of this method has been tested by comparison of theoretical densities determined from the estimated critical properties with experimental values. Absolute deviations ranging from 0 % to 17.4 % were observed for the estimated density values. An overall average absolute deviation of 4.9 % was observed for the studied DESs. Absolute deviations for DESs consisting of aliphatic precursors ranged from 0 % to 9.5 %, whereas for DESs consisting of at least one aromatic precursor, these ranged from 5.8 % to 17.4 %. The accuracy fell as the percentage of hydrogen-bond donors (HBD) increased. The method was also found to accurately take into account the variation in density due to a temperature change.