Liquid–liquid equilibria for ternary systems of (ethylene glycol + toluene + heptane) at temperatures (303.15, 308.15, and 313.15) K and atmospheric pressure: Experimental results and correlation with UNIQUAC and NRTL models

The liquid–liquid equilibria (LLE) were measured for ternary mixtures of (ethylene glycol + toluene + n-heptane) under atmospheric pressure and at temperatures (303.15, 308.15, and 313.15) K. The experimental distribution coefficient and selectivity factor were obtained to evaluate the efficiency of the solvent for extraction of toluene from n-heptane. The degree of consistency of the experimental LLE results was validated by applying the Othmer–Tobias equation. The LLE data of the studied mixtures were used to obtain binary interaction parameters in the NRTL and UNIQUAC models by minimizing the root mean square deviations (RMSD) between the experimental and the calculated results of two-phase compositions. The calculated compositions based on the UNIQUAC and NRTL models were found to be in good agreement with the experimental values. The results of the RMSD for the NRTL and UNIQUAC models are about 0.0144 and 0.0149, respectively.

► LLE were measured for (ethylene glycol + toluene + heptane) at (303.15,308.15, and 313.15) K. ► The UNIQUAC and NRTL models were used to correlate the LLE data. ► The reliability of experimental data was tested applying Othmer–Tobias correlation. ► The RMSDs obtained are 0.0144 for the NRTL model and 0.0149 for the UNIQUAC model.