Isobaric Vapor Liquid Equilibrium (VLE) Data of the Systems Ethylene Glycol-Glycerol and 1,2-Propylene Glycol-Ethylene Glycol at 20Pa

Abstract

Vapor liquid equilibria (VLE) of two binary mixtures (ethylene glycol + glycerol and 1,2-propylene glycol + ethylene glycol) were measured at 20Pa. The experimental data satisfy the thermodynamic consistency by Herington method. The vapor phase can be considered as ideal phase, while the non-ideality of the liquid phase was symbolized by Wilson and NRTL activity coefficient models. The experimental data were regressed and correlated by nonlinear least square method of Matlab optimization toolbox. It is found that under the medium vacuum the relative deviations between experimental data and calculated results by the activity coefficient models for low and moderate pressures are larger than 50%. Hence a cubic polynomial regarding the molar composition of liquid phase as the correction of the models was proposed and used in regression to get the interaction parameters. The results showed that the relative deviations between calculated and experimental data are smaller than 1%. The corrected models can provide a calculation basis or data reference for medium vacuum distillation.

Isobaric Vapor–Liquid Equilibrium for Two Binary Systems{Propane-1,2-diol + Ethane-1,2-diol and Propane-1,2-diol + Butane-1,2-diol} at p = (10.0, 20.0, and 40.0) kPa

“…Until now, the isobaric VLE data of the propane-1,2-diol + ethane-1,2-diol and propane-1,2-diol + butane-1,2-diol systems are relatively scarce in published papers. 2,6,7 Thus, in this work, the isobaric vapor−liquid equilibrium data of propane-1,2-diol + ethane-1,2-diol and propane-1,2-diol + butane-1,2-diol systems were measured at the pressures of (10.0, 20.0, and 40.0) kPa. Furthermore, the experimental VLE data of the two systems at 10.0 kPa were compared with the previous data measured by Zhang et al.…”

Separation of a Close-Boiling 1,2-Propanediol and Ethylene Glycol Mixture Using Pressure-Related Distillation

“…The VLE relationship of the glycol system is verified by the experimental data to prove the accuracy of the parameters of the thermodynamic model . Much work − has been done on the VLE data of the binary system in recent years. Zhang et al have measured the VLE data of EG + 1,2-PG at 10 kPa .…”