Determination of phase equilibria and densities for the quaternary system toluene plus acetone plus phenol plus water

The success of modeling mass transfer depends strongly on the accurate description of the physical properties of the system involved. In the case of two liquid phases the knowledge of the liquid-liquid equilibrium is of special importance. This knowledge gains importance when the transfer of multiple species is to be modeled, as more complex interactions have to be considered. These can only be described with advanced mass-transfer models, such as the Stefan-Maxwell model, with a high demand on accuracy in the description of physical properties. The quaternary system toluene + acetone + phenol + water is being considered as a possible new standard test system for the investigation of multicomponent mass transfer in liquid-liquid extraction. Equilibrium data are needed: experimentally determined tie-line data at 20 degrees C are now presented for this system. The results are correlated with the UNIQUAC model using different objective functions. The resulting calculated data sets are compared considering their accuracy and applicability to multicomponent mass-transfer description. The densities of various mixtures of the system have been measured and correlated.