Liquid–Liquid Equilibrium Measurement and Thermodynamic Modeling of the Ternary System (Water + 2,2-Difluoroethanol + 1-Hexanol/1-Heptanol/1-Octanol/1-Nonanol) at 303.2 K

Abstract

In this study, we measured the liquid–liquid equilibrium (LLE) data of the ternary system {water + 2,2-difluoroethanol + solvent (1-hexanol, 1-heptanol, 1-octanol, and 1-nonanol)} at 303.2 K and 101.3 kPa. The distribution coefficient (D) and separation factor (S) of the solvent were calculated from the experimental data to examine the extraction performance of the solvent, and the results showed that the solvent extraction capacity increased with the increase in the number of carbon atoms. The NRTL and UNIQUAC activity coefficient models were applied to correlate the experimental values and optimize the binary interaction parameters. The reliability of the binary interaction parameters was verified by a hybrid surface analysis on the basis of the Gibbs energy topology. The root-mean-square error (RMSD) values of both models were below 0.01%, which implies that both models are suitable for correlating the LLE experimental data of this study. In addition, the interaction forces between the solvent and {water + 2,2-difluoroethanol} were also analyzed by σ-profile.

Measurement and Correlation of Liquid–Liquid Equilibrium for the Ternary System 1-Octyl-3-methylimidazolium Tetrafluoroborate + 1-Ethyl-3-methylimidazolium Tetrafluoroborate + Water

“…The extraction performance of the solvent is often expressed by the distribution coefficient D and selectivity S . − The distribution coefficients and selectivity are defined by the following equation. The higher the selectivity coefficient, the better the separation effect will be.…”