Ilham Mokbel

Phase equilibrium properties of binary mixtures containing a diesel compound (n-dodecane) + biodiesel compounds (ethyl hexanoate, ethyl decanoate and ethyl tetradecanoate)

The vapor pressures of three binary systems ethyl hexanoate (1)xa0+xa0n-dodecane (2), ethyl decanoate (1)xa0+xa0n-dodecane (2) and ethyl tetradecanoate (1)xa0+xa0n-dodecane (2) were measured by means of a static apparatus at temperatures between 373.15 and 453.15xa0K. The data were correlated with the Antoine equation. From these data, the molar excess Gibbs energies GE were obtained with Barker’s method and fitted to the Redlich–Kister equation. The excess Gibbs energy is positive for all the investigated constant temperatures and over the whole composition range. The Wilson equation was used and good results were obtained in the prediction of the total pressure and thermodynamic excess properties; however, deviations were observed with respect to the experimental and predicted GE, using UNIFAC (Dortmund) group contribution model.