Vapor pressures of diethyl carbonate + ethanol binary mixture and diethyl carbonate + ethanol + isooctane/toluene ternary mixtures at temperatures range of 303.15–323.15 K

The vapor pressures of a diethyl carbonate + ethanol binary mixture and two ternary mixtures containing diethyl carbonate + ethanol + isooctane/toluene with constant ethanol mass fractions of 20% were measured at temperatures ranging from 303.15 to 323.15 K using a simple quasi-static ebulliometer. The experimental data show that the vapor pressure decreases with increasing diethyl carbonate (DEC) fraction in the solution for all mixtures studied. The vapor pressure of the binary mixture correlated well with the Wilson, nonrandom two-liquid (NRTL) and universal quasichemical (UNIQUAC) models and gave an average absolute deviation (AAD) of 1.2%. The experimental data of the ternary mixtures were compared with predicted vapor pressures calculated using Wilson, NRTL and UNIQUAC models based on binary mixture parameters, which were obtained from binary data only. The performance of the group contribution method of the UNIQUAC functional activity coefficient (UNIFAC) model in predicting the vapor pressures of the systems was also studied. The AADs between experimental and predicted vapor pressures were 4.7%, 3.2%, 4.8% and 1.4% for the DEC + ethanol + isooctane mixture and 1.4%, 3.2%, 2.1% and 6.8% for the DEC + ethanol + toluene mixture using the Wilson, NRTL, UNIQUAC and UNIFAC models, respectively. The performance of the UNIFAC model was found to be comparable with that of the Wilson, NRTL and UNIQUAC models for the mixtures studied.