Isobaric vapor–liquid equilibrium of three binary systems containing dimethyl succinate, dimethyl glutarate and dimethyl adipate at 2, 5.2 and 8.3 kPa

The isobaric vapor–liquid equilibrium (VLE) data for three binary systems of dimethyl succinate (DMS) + dimethyl glutarate (DMG), dimethyl succinate +  dimethyl adipate (DMA) and dimethyl glutarate + dimethyl adipate were determined at 2, 5.2 and 8.3 kPa with a dynamic recirculating apparatus and the temperature ranged from 363.39 to 422.4 K. All the experimental data were verified to be thermodynamically consistent according to the Herington method and point to point method of Van Ness test. Afterwards, the VLE data were correlated with Nonrandom two-liquid (NRTL), Wilson and UNIQUAC activity coefficient models, and the interaction parameters of thermodynamic models of these three binary systems were obtained. The results indicated that the calculated values of these three models agreed well with the experimental data, while the NRTL model and UNIQUAC model provided a slightly better result than Wilson model. The calculated root mean square deviations of NRTL model for the temperature and vapor-phase mole fraction were less than 0.13 K, and 0.0023, respectively.