Simultaneous description of excess enthalpy and vapour-liquid equilibrium data of associated mixtures by means of a lattice-fluid model

Excess enthalpies (H-epsilon) and vapour-liquid equilibrium (VLE) data for several associated mixtures have been analysed by means of the lattice-fluid model (LF) and the lattice-fluid associated solution model (LFAS). The systems considered were selected in order to include a variety of associated solutions, and exhibit self- and cross-association interactions. The inclusion of the chemical contribution in the LFAS model makes it necessary to fit any parameter within the physical contribution. In general, the LFAS model represents an improvement in the overall description of the excess functions of associated mixtures, while in some cases the use of the LF model leads to unrealistic values of the physical interaction parameters.