The New Method for Correlation and Prediction of Thermophysical Properties of Fluids. Critical Temperature

Abstract

On the basis of the linear free energy relationships theory and thermodynamics formulas, a new method predicting critical temperature (Tc) of pure fluids is proposed for the first time. Sixteen homologues of 616 substances have been regressed and correlation equations between Tc and molecular descriptors are obtained. The mean relative deviations of the 16 equations are from 0.01% to 2.73%, and most of them are under 2%. In addition, the squared correlation coefficients are from 0.90 to 0.98. Moreover, the equations are tested through cross-validation by the leave-one-out procedure and most of the squared correlation coefficients are greater than 0.90. The results reveal that the equations exhibit better effect with simple form of equation, high prediction accuracy, and definitude theory meaning. This study successfully combines macroscopic physical properties of fluids with their molecular microstructure and breaks through the experimental or theoretical application scope, perfecting calculation of criti...