PREDICTION AND CORRELATION OF EXCESS ENTHALPY AND EXCESS GIBBS ENERGY OF THE 1-ALKANOL + N-ALKANE SYSTEMS

The vapour pressure, excess Gibbs energy and the temperature dependence of excess enthalpy of the 1-alkanol + alkane solutions are predicted by means of the two-constant athermal Mecke-Kempter model combined with the modified NRTL equation. The chemical contributions to the excess enthalpy (H(E)) and excess Gibbs energy (G(E)) are calculated from the knowledge of the standard association functions of a single 1-alkanol, selected as a reference compound. The energetic parameters of the modified NRTL equation are determined on the basis of the experimental H(E) data of a given 1-alkanol + n-alkane system at an arbitrarily selected temperature. The values predicted agree well with the experimental data of 109 excess enthalpy and 24 vapour-liquid equilibrium (VLE) data sets.