AN IMPROVEMENT FOR THE EXCESS ENTHALPY PREDICTION BY UNIFAC .1. BINARY-MIXTURES CONTAINING ALKANES

The UNIFAC model is tested for its ability to correlate and predict bi nary excess enthalpies. Besides the alkanes containing systems from ea rlier work, those for ester-alkane mixtures are also investigated. The model is fitted to binary excess enthalpy data. The influence of grou p surface area parameters is also examined by using values based on th e van der Waals surface areas Q, multiplied for all the groups by the factor n. A significant improvement of H(E) calculation in most of the systems considered is observed if the factor n is taken equal to 3.