Isobaric Vapor–Liquid Equilibrium (VLE) of Acrylonitrile and Adiponitrile at 7.0, 12.0, 17.0, and 22.0 kPa

Abstract

Isobaric vapor–liquid equilibrium (VLE) data for binary mixtures of acrylonitrile and adiponitrile were measured using a modified Rose–Williams still at temperatures ranging from 283.4 to 506.8 K and pressures of 7.0, 12.0, 17.0, and 22.0 kPa. The consistency of the VLE data was evaluated using the methods proposed by Wisniak and Fredenslund. Five activity coefficient models (Margules, van Laar, NRTL, Wilson, and UNIQUAC) were employed to correlate the VLE data, estimate binary interaction parameters, and calculate the excess Gibbs free energy of the mixtures. The regression results were assessed using the root-mean-square error for temperature (RMST) and the root-mean-square error for vapor phase mole fraction (RMSy₁). The Margules and van Laar models exhibited higher temperature and vapor phase fraction deviations, whereas the Wilson, NRTL, and UNIQUAC models performed better. Among all models tested, the NRTL model demonstrated the highest predictive accuracy, with RMST and RMSy₁ values below 0.04 and 0.0005, respectively.