Experimental Measurement and Modeling of Vapor-Liquid Equilibrium for the Ternary System Water plus Acetonitrile plus Ethylene Glycol

This paper presents vaporliquid equilibrium (VLE) measurement and correlation for water + acetonitrile + ethylene glycol. Isobaric VLE data were reported for the ternary system at p = 101.3 kPa. The NRTL model was used for the correlation with binary parameters of water + ethylene glycol being fixed as the same for water + ethanol + ethylene glycol in the literature. The correlation showed good agreement with experimental data. Mean absolute deviations were 0.15 K for equilibrium temperature and 0.0025 for vapor-phase mole fraction of acetonitrile, respectively. The reliability of the present correlation was also verified in terms of activity coefficients of water and acetonitrile and relative volatility of acetonitrile to water. With the addition of ethylene glycol, the azeotrope of water + acetonitrile can be removed at a glycol mole fraction of 0.277. Comparisons were presented for correlations available in the literature. Effect of ethylene glycol on water + acetonitrile was compared with that on water + alcohol.