Total vapour pressure and excess Gibbs energy of ethanol with 1,8-cineole at temperatures between 278.15 K and 323.15 K

Vapour pressures of (ethanol + 1,8-cineole) at 10 temperatures between 278.15 and 323.15 K were measured by a static method. The reduction of the vapour pressures for obtaining activity coefficients and excess molar Gibbs energies was carried out by fitting the vapour pressure data to the Wilson equation according with Barker's method. Three equations of state (EOS) were used to correlate the vapour–liquid equilibrium (VLE) and for describing the volumetric behaviour of the mixture. Two of them are modifications of the Peng–Robinson equation as proposed by Mathias (PRM) and by Stryjek–Vera (PRSV). In both cases, a volume translation (VT) according to Peneloux was considered. The third model applied is based on the theory of perturbations: statistical associating fluid theory (SAFT). The best description of the phase equilibrium was achieved by the Stryjek–Vera modification, whereas SAFT provided the best volumetric results.

► Measurement of vapour pressures of ethanol + 1,8-cineole between 278.15 and 323.15 K.
► Calculation of activity coefficients and GmE according to Wilson model.
► Consistency thermodynamic test through Gibbs–Helmholtz equation.
► Correlation of VLE data with 3 equations of state (PRM, PRSV and SAFT).
► Cubic EOS show the best VLE correlations and SAFT gives the best VE behaviour.