Measurement and Correlation of Vapor–Liquid Equilibrium for Binary Mixtures Composed of m-Xylene, Ethylbenzene, and 1, 2, 4-Trichlorobenzene at 101.3 kPa

The extractive distillation was used to separate ethylbenzene and m-xylene. After the solvent screening, 1,2,4-trichlorobenzene was chosen as the extractive solvent. The vapor–liquid equilibrium (VLE) of binary mixtures of m-xylene, ethylbenzene, and 1,2,4-trichlorobenzene was measured at 101.33 kPa. The measurements were taken with a modified Rose equilibrium still. The Wisniak’s test was used to assess the thermodynamic consistency of the VLE experimental results. To obtain the binary interaction parameters, the binary VLE experimental data were correlated with the NRTL, Wilson, and UNIQUAC activity coefficient models. The results showed that three models all fit the experimental values of three binary systems well, and the ternary VLE data of m-xylene + ethylbenzene + 1,2,4-trichlorobenzene were estimated using Aspen Plus V11 based on these model parameters. The experimental data agree well with the estimation values generated from three models. Finally, the effect of 1,2,4-trichlorobenzene as an extractant was analyzed, and it is proved to have a good influence on the separation of ethylbenzene from mixed xylenes by extractive distillation.