VAPOR-LIQUID-EQUILIBRIA FOR METHANOL PLUS TETRAETHYLENE GLYCOL DIMETHYL ETHER

Vapor-liquid equilibrium (P-T-x) for the methanol + tetraethylene glycol dimethyl ether binary system were obtained by the static method in the range of temperatures from 293.15 to 423.15 K at 10 K intervals. The modified vapor pressure apparatus used is described. The Kuczynsky method was used to calculate the liquid and vapor composition and the activity coefficients of methanol from the initial composition of the sample and the measured pressure and temperature. The results were correlated by the NRTL and UNIQUAC temperature dependent activity coefficient models. This system shows nearly ideal behavior at 323.15 K, but positive deviations from ideality at lower temperatures and negative deviations at higher temperatures are observed. The activity coefficients become more negative with the increase in temperature and mole fraction of methanol. The excess molar enthalpy using the Gibss-Helmholtz equation and the NRTL and UNIQUAC parameters were calculated at 303.15 K and compared with experimental data.