Premium
Equation of state for pure fluids and mixtures based on a truncated virial expansion
Author(s) -
Anderko Andrzej,
Pitzer Kenneth S.
Publication year - 1991
Publication title -
aiche journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.958
H-Index - 167
eISSN - 1547-5905
pISSN - 0001-1541
DOI - 10.1002/aic.690370910
Subject(s) - virial coefficient , acentric factor , equation of state , thermodynamics , chemistry , virial expansion , virial theorem , vapor pressure , series (stratigraphy) , compressibility factor , binary number , mixing (physics) , physics , mathematics , paleontology , arithmetic , quantum mechanics , galaxy , biology
An accurate, yet simple, equation of state was developed for pure fluids ranging from nonpolar to H 2 O and their mixtures. The equation consists of a virial expansion truncated after the fourth virial coefficient and a closed‐form term approximating higher coefficients. For nonpolar or weakly polar compounds, the equation is generalized using critical temperature, critical pressure, and acentric factor. Despite its simplicity, the equation represents the P‐V‐T and saturation properties of pure fluids with a very good accuracy, which is comparable to that of multiparameter, generalized BWR‐type equations. For mixture calculations, mixing rules were formulated based on the rigorously known composition dependence of virial coefficients. The equation represents vapor‐liquid, gas‐gas and liquid‐liquid equilibria, as well as volumetric properties of mixtures containing nonpolar components and/or water. Binary parameters can be generalized for series of mixtures containing a common component.