Isobaric vapor–liquid–liquid equilibria with a newly developed still

A new and simple apparatus for the measurement of isobaric vapor–liquid–liquid equilibrium (VLLE) is developed by modifying the still proposed by van Zandijcke et al. The still is used to measure the isobaric vapor–liquid equilibrium (VLE) data for the system ethanol–water, the isobaric VLE and VLLE data for the binary systems water–1-butanol and 2-butanol–water at atmospheric pressure. The obtained data for the binary systems are compared with the previous data in the literature. The thermodynamic consistencies of the obtained data for the binary systems are confirmed by the Herington’s area test. Furthermore, the isobaric VLLE data for the ternary systems ethanol–water–1-butanol and ethanol–2-butanol–water are obtained with the apparatus. The results show that the apparatus can be applied to the measurements of both isobaric VLE and VLLE successfully.