In this paper, isobaric vapor–liquid equilibrium (VLE) data for the binary system of γ-butyrolactone + succinic anhydride were measured at pressures of 20.0, 30.0, and 40.0 kPa by a modified Rose still. There was no azeotropic phenomenon observed at each pressure. A thermodynamic consistency test is a way to verify the reliability of the experimental data. The VLE data were tested by a Herington area test and Van Ness point test. Then, the VLE data showed a good correlation with nonrandom two-liquid (NRTL) and Wilson activity coefficient models.

The isobaric vapor–liquid equilibria (VLE) data for two binary systems of propylene glycol methyl ether acetate (PMA) + N,N-dimethylformamide (DMF) and propylene glycol methyl ether acetate (PMA) + methanol (MeOH) at 30.0, 50.0, and 70.0 kPa were measured by utilizing a modified Rose–Williams still type apparatus which could be able to quickly form the dual cycle of continuous vapor and liquid phase in this work. On the basis of Herington area test and Van Ness point test, the thermodynamic consistency of the experiment data was verified. Meanwhile, VLE data that we obtained were correlated with nonrandom two-liquid (NRTL) and Margules activity coefficient models. The results demonstrated that the calculated values were in good conformity with the experimental data in this study. In addition, azeotropic behavior was observed in the binary system of PMA and DMF at reduced pressures.