LLE, VLE and VLLE data for the water–n-butanol–n-hexane system at atmospheric pressure

Isothermal liquid–liquid equilibria were measured for the water–n-butanol–n-hexane system at 313.15 K. Isobaric vapor–liquid (VLE) and vapor–liquid–liquid equilibria (VLLE) were measured for the same system at normal atmospheric pressure using an all-glass dynamic recirculating still with an ultrasonic homogenizer coupled to the boiling flask.The experimental LLE, VLE and VLLE data were found to be thermodynamically consistent. The data was correlated using the NRTL and UNIQUAC models and predicted by means of UNIFAC. The parameters set thus obtained reproduces the LLE experimental data appropriately. However, it has been difficult to correlate the VLLE data and only the NRTL model produces an acceptable solution.

► n-Hexane can be a suitable solvent to dehydrate butanol to be used as a fuel. ► Isothermal LLE experimental data has been determined at 313.15 K and agrees well with literature. ► New isobaric VLE and VLLE have been obtained at 101.3 kPa. ► All the data has been correlated using different thermodynamic models.