Isobaric vapor-liquid equilibrium of acetone + methanol system in the presence of calcium bromide

This paper gives experimental vapor-liquid equilibrium (VLE) measurements of the acetone + methanol system in the presence of calcium bromide (CaBrz). The influence of the addition of CaBr₂ on the VLE was investigated using an Othmer recirculation-type still. The VLE data were presented in terms of the enhancement factor. Furthermore, an assessment of thermodynamic models is presented by applying thermodynamic consistency test as well as the Wilson activity coefficient model, coupled with several equations of state, to the measured data. Analysis of the results suggests that adding CaBr₂ to acetone + methanol system leads to a crossover behavior; a mixture of salt-in and salt-out effects. In particular, the addition of 0.3 M CaBr₂ was found to eliminate the azeotropic point of acetone + methanol system.