DISQUAC structure-dependent interaction parameters for mixtures containingsec-alkanols and benzene, toluene, or n-alkanones

Mixtures containing sec-alkanols and benzene, toluene, or n-alkanones are c haracterized in terms of DISQUAC by means of structure-dependent interactio n parameters. The quasichemical (QUAC) interchange coefficients are indepen dent of the size alcohol for a given organic solvent; while the dispersive (DIS) ones change with the size of the alcohol. This behaviour has been fou nd for other many alcoholic solutions. DISQUAC represents well the thermody namic properties of these mixtures: vapor-liquid equilibria, VLE, molar exc ess Gibbs energies, G(E), and molar excess enthalpies, H-E. So, the mean de viations between experimental and calculated results are about 2% for press ure, and 8% for H-E. A Short comparison between DISQUAC results and those g iven by the Dortmund version of UNIFAC, the UNIQUAC association theory and other similar model is also presented. In the case of the Dortmund version of UNIFAC, poorer predictions are obtained for H-E, as this property is mor e sensitive to molecular structure. Association theories provide better res ults because are used as correlation equations.