Vapor–liquid equilibrium for propylene glycols binary systems: Experimental data and regression

• VLE data are reported for five binary systems involving propylene glycols.
• VLE data are measured in temperature range of 350.15–510.15 K.
• The VLE experimental data were correlated with the NRTL model.
• Results from NRTL model are compared with data calculated by IDEAL and UNIFAC models.
• NRTL model with our parameters shows different behavior than IDEAL and UNIFAC models

Vapor–liquid equilibrium (VLE) data are reported for five binary systems involving propylene glycols. VLE data have been measured in the temperature range of 350.15–510.15 K and pressure up to 34.374 kPa for the binary systems: 1,2-propanediol (monopropylene glycol, MPG) + 2-[2-(2-hydroxypropoxy) propoxy]propan-1-ol (tripropylene glycol, TPG), MPG + 2-(2-[2-(2 hydroxypropoxy) propoxy]propoxy) propan-1-ol (tetrapropylene glycol, TePG), 1-(2-hydroxypropoxy) propan-2-ol (dipropylene glycol, DPG) + TPG, DPG + TePG and TPG + TePG. These experimental data are obtained using an equilibrium apparatus build in our laboratory. For the binary system MPG + DPG there are VLE data available in literature. The experimental data obtained were correlated using the NRTL model. These VLE data are essential for the process design in order to separate propylene glycols mixtures by distillation.