Isobaric vapor–liquid equilibrium for binary system of methanol and acetonitrile

Isobaric vapor–liquid equilibrium (VLE) data for methanol and acetonitrile system was measured at 101.3 kPa by using equilibrium still. The results show that methanol and acetonitrile system can form a minimum temperature azeotrope. Thermodynamic consistency of the experimental data was confirmed by means of Herington semi-empirical method. The experimental values obtained were correlated by using the Margules, Van Laar, Wilson and NRTL activity-coefficient models, respectively. The binary interaction parameters of the activity-coefficient models were determined. The average absolute deviation in boiling point and vapor-phase composition were determined by comparing the experimental values with those calculated by the activity-coefficient models. The calculated maximum average absolute deviations were 0.25 K and 0.0056 for the boiling point and vapor-phase composition, respectively. Therefore, it was shown that the four activity-coefficient models used satisfactorily correlate the experimental results of methanol and acetonitrile system.