Isobaric Vapor–Liquid Equilibrium Data for the Near-Boiling System 2-Ethyltoluene + 1,3,5-Trimethylbenzene + N -Methyl-2-pyrrolidone or Dimethyl Phthalate at 101.3 kPa

Abstract The vapor–liquid-phase equilibrium (VLE) data for binary systems 1,3,5-trimethylbenzene (1,3,5-TMB) + 2-ethyltoluene (2-ETL), 1,3,5-TMB + N-methyl-2-pyrrolidone (NMP), 2-ETL + NMP, 1,3,5-TMB + dimethyl phthalate (DMP), 2-ETL + DMP and for ternary systems 1,3,5-TMB + 2-ETL + NMP, 1,3,5-TMB + 2-ETL + DMP were measured at 101.3 kPa. The data were tested for thermodynamic consistency by Fredenslund’s test and the Van Ness test. The VLE data were correlated using the Wilson, NRTL, and UNIQUAC thermodynamic models, and the binary interaction parameters for each model were obtained. The root-mean-square deviation and average absolute deviation were calculated to evaluate the accuracy of these models, and the results show that the experimental values are in good agreement with the calculated ones. The VLE data for the two ternary systems were predicted using the binary interaction parameters, and the predicted ternary VLE data are consistent with the experimental data. This study provides reliable fundamental data for the design and development of the 1,3,5-TMB/2-ETL separation process.