Experimental Determination and Correlation of Liquid–Liquid Equilibrium Data for Ternary Systems of Dodecane + 1-Methylnaphthalene + Solvent

Liquid–liquid equilibrium (LLE) data for the ternary system of dodecane + 1-methylnaphthalene + solvent were experimentally determined at 298.2 K and 101.3 kPa using N-methylimidazole, trimethyl phosphate, furfural, N,N-dimethylacetamide, benzyl alcohol, triethyl phosphate, and ethylene glycol as extractants. Using the obtained LLE data, the distribution constant, separation factor, and performance index were calculated to evaluate the performance of these extractants in extracting and separating 1-methylnaphthalene from dodecane. The reliability of the LLE data was examined using the Hand and Othmer–Tobias equations, with the correlation coefficients of the fitted equations exceeding 0.96. Furthermore, the nonrandom two-liquid (NRTL) and universal quasichemical (UNIQUAC) thermodynamic models were used to correlate the LLE data and obtain binary interaction parameters. The root-mean-square deviations between the experimental and calculated results were 0.15–0.97 for NRTL and 0.13–1.05 for UNIQUAC. The derived binary interaction parameters were validated using GMcal_TieLinesLL, a specialized software package for LLE calculations. These findings highlight that both the NRTL and UNIQUAC thermodynamic models can accurately describe the liquid–liquid phase equilibrium behavior of ternary systems, providing a theoretical basis for the industrial application of catalytic cracking diesel extraction and aromatics removal technology.