Prediction of enthalpy and entropy departures using a two-fluid corresponding-states principle

Abstract

The generalized corresponding-states principle (GCSP), based on the properties of two nonspherical reference fluids, has been shown to be a powerful technique for the correlation and prediction of thermodynamic properties. In this work we show GCSP calculations of enthalpy and enropy departures for pure fluids and fluid mixtures. The mixtures studied include those conforming well to traditional corresponding states theory (e.g., n-pentane + n-octane), as well as those that have not hitherto been amenable to such treatments (e.g., n-pentane + ethanol). It is shown that the GCSP method works well for all classes of mixtures and compares favorably with other methods of prediction. The use of cubic equations of state to represent the reference fluids gives the GCSP method flexibility while maintaining accuracy in the prediction. No adjustable parameters are required in the GCSP calculations of enthalpy and entropy departures.