Pure Component Constants

Basic pure component constants required to characterize components or mixtures for calculation of other properties include the melting point, normal boiling point, critical temperature, critical pressure, critical volume, critical compressibihty factor, acentric factor, and several other characterization properties. This section details for each propeidy the method of calculation for an accurate technique of prediction for each category of compound, and it references other accurate techniques for which space is not available for inclusion. 

A pure component constant that is occasionally used in property correlations is the enthalpy of vaporization at the normal boiling point, AHvbp. In addition, several special estimation methods are suggested. The Chen equation (15) gives a relation among the enthalpy of vaporization, the reduced vapor pressure, and the reduced temperature. When applied to the normal boiling point, Eq. 2 is obtained, with an average error of 2% ... 

These are the pure component constants of acetone for the PRSV EOS from Table 3.1.1.)... 

The pseudo-critical constants are calculated and tabulated along with the pure component constants ... 

Pure-component constants used by Chao-Seader12 and Grayson-St reed2 5 for the Hildebrand... 

In these equations, a, and 6, are the pure component constants in the equation of state as defined by Eqs. 2 and 3. A survey about the current status and potential of the PSRK equation of state has been recently presented by Horstmann et al. [15]. Different fields of... 

The same equations are used for Bijy but with characteristic parameters Pc TC j, and in place of the pure-component constants. The former are related to the latter through the following mixing rules ... 

Xj. = Adjustable parameter in the UNIFAC equation = Pure-component constant. 

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