Vapor–liquid–liquid equilibrium and vapor–liquid equilibrium for the quaternary system water–ethanol–cyclohexane–toluene and the ternary system water–cyclohexane–toluene. Isobaric experimental determination at 101.3 kPa

Experimental isobaric vapor–liquid–liquid and vapor–liquid equilibrium data for the ternary system water (1)–cyclohexane (2)–toluene (3) and the quaternary system water (1)–ethanol (2)–cyclohexane (3)–toluene (4) were measured at 101.3 kPa. An all-glass, dynamic recirculating still equipped with an ultrasonic homogenizer was used to determine the VLLE. The results obtained show that the system does not present quaternary azeotropes. The point-by-point method by Wisniak for testing the thermodynamic consistency of isobaric measurements was used to test the equilibrium data.

• Water–ethanol–cyclohexane–toluene and water–cyclohexane–toluene isobaric VLLE. • Isobaric experimental data were determined at 101.3 kPa. • A dynamic recirculating still with an ultrasonic homogenizer was used. • The quaternary system does not present quaternary azeotropes.