Measurement and correlation of isobaric vapor-liquid equilibrium data for m-xylene, ethylbenzene, and 2-methyl-1-butanol

The near-boiling system of ethylbenzene-m-xylene is difficult to be separated by ordinary distillation, and the special distillation method is an effective method to realize the separation of the two. Therefore, the phase behavior between 2-methyl-1-butanol and ethylbenzene and m-xylene was studied, and the separation of ethylbenzene-m-xylene system by azeotropic distillation was explored. The isobaric vapor-liquid equilibrium (VLE) data of ethylbenzene + 2-methyl-1-butanol, m-xylene + 2-methyl-1-butanol were determined at 101.325 kPa using an Ellis equilibrium still. All data passed the Wisniak point test and were consistent with thermodynamic consistency. Wilson, NRTL and UNIQUAC thermodynamic models were used to correlate the experimental data, and the root mean square deviation and absolute deviation between the experimental values and the correlation results were calculated. The results showed that the RMSD of the vapor phase composition of the three thermodynamic models did not exceed 0.00332, and the UNIQUAC model had the best fitting effect. This work provides basic data for the design of azeotropic distillation separation process of ethylbenzene-m-xylene.