Isobaric Vapor-Liquid Equilibria for the Binary System of Adiponitrile and Cyclopentanone at 5 and 10 kPa

The isobaric vapor-liquid equilibrium (VLE) data for the binary system of adiponitrile + cyclopentanone at 5 and 10 kPa were determined with a modified Rose-Williams still. The reliability of the apparatus was verified by the measurements of the vapor pressure of cyclopentanone and water at varying temperatures. The thermodynamic consistency of VLE data was tested by methods suggested by Wisniak and Van Ness. Five activity coefficient models, including van Laar, Margules, Wilson, NRTL, and UNIQUAC models, were used to correlate the VLE data, and the excess Gibbs free energy of the binary system was determined. The parameters of the five activity coefficient models were obtained using the experimental data, and the regression results were evaluated by RMST (defined by eq 12) and RMSy(1) (defined by eq 13). The results show that the deviation of temperature calculated by the Margules model is larger than those calculated by other models, and the Wilson, NRTL, and UNIQUAC models are all acceptable for this system. Furthermore, the UNIQUAC model shows the best prediction accuracy among these models with RMST and RMSy(1) less than 1.2 and 0.007, respectively.