Vapor‐Liquid equilibrium: Part I. An appraisal of data reduction methods

Abstract

Correlations of the excess Gibbs function and the activity coefficients of a binary, liquid‐phase system at constant temperature depend on reduction of P‐x‐y data taken for the system in vapor‐liquid equilibrium. It is shown that use of a full P‐x‐y data set is for all practical purposes based on just the P‐y values. Alternative procedures require only P‐x or P‐y data. In any case, effective use of a full P‐x‐y data set can be made only if redundent experimental values of Px,y or P are compared for consistency with calculated values. This cannot be accomplished by means of the popular area test for thermodynamic consistency.

Vapor-liquid equilibrium measurements for the binary system methyl acetate+ethanol at 0.3 and 0.7 MPa

“…VLE experimental data in this paper were verified by using the thermodynamic consistency test of Van Ness et al (1973). The proposed computer program of Fredenslund et al, (1977) was applied using physical properties from the literature (Fredenslund et al, 1977;Riddick et al, 1986;Yaws, 2003) and the correlations of the vapor pressures from a previous paper (Susial et al, 2010).…”

“…The experimental data of this paper at 0.1, 0.3 and 0.7 MPa were verified thermodynamically using the point-to-point test of Van Ness (Van Ness et al, 1973) and by applying the procedure of Barker (Barker, 1953) implemented in the computer program of Fredenslund et al (1977).…”

Measurement and correlation of isobaric vapor-liquid equilibrium for the binary system of cyclopentane and tetrahydrofuran

“…Thermodynamic consistency of the experimental results was checked by means of two tests: (1) the point-to-point van Ness method (Van Ness et al, 1973) and (2) the Herington method (Herington, 1951).…”

Application of a Thermodynamic Consistency Test to Binary Mixtures Containing an Ionic Liquid

“…Then the proposed test is a modeling procedure, similar to the Van Ness-Byer-Gibbs test [21]. Once the model parameters are determined and the calculated solubilities are within acceptable limits of deviations, the Gibbs-Duhem equation is applied.…”