Isobaric vapor-liquid equilibria for water + acetic acid + N-methylacetamide

Isobaric vapor-liquid equilibria data for the binary system of acetic acid + N-methylacetamide and the ternary system of water + acetic acid + N-methylacetamide were measured at 101.33 kPa by using an improved Rose still. The average relative volatility of water + acetic acid system is 5.96 when N-methylacetamide is used as extractant. The measured VLE data of the binary system were verified by the thermodynamic consistency test and were correlated by NRTL, Wilson and UNIQUAC models, respectively. The obtained NRTL interaction parameters for the acetic acid + N-methylacetamide system, 3 groups of NRTL interaction parameters of water + acetic acid system and 2 groups of water + N-methylacetamide system quoted from the literatures were used to predict the VLE data of the ternary system mentioned above. The predicted values of the ternary system agree well with the experimental results. The average absolute deviations of the vapor-phase mole fractions of water, acetic acid and N-methylacetamide are respectively less than 0.0176, 0.0149 and 0.0064, and the average absolute deviation of the equilibrium temperature is less than 1.91°C.