Thermodynamics of Ternary Alcohol -Saturated Hydrocarbon Mixtures

A theory is presented to predict the excess thermodynamic functions of ternary mixtures including one alcohol and two saturated hydrocarbons frombinary data. The one-parameter Flory-Huggins equation is applied to describethe excess Gibbs free energy data of binary hydrocarbon mixtures with physical and size effects. The Kretschmer Wiebo equation is used for alcohol-saturated hydrocarbon mixtures having physical and strong chemical interactions. The two equations are combined to derive expressions for the excess Gibbs freenergy, the excess enthalpy of mixing, and the excess heat capacity data ona ternary alcohol-saturated hydrocarbon mixture. Prediction is shown to be successful for these three thermodynamic functions of the ethanol-cyclohexane-n-heptane system.