A new four‐parameter cubic equation of state for mixtures. Vapor–liquid equilibrium calculations

Abstract

A new four‐parameter cubic equation of state has been recently developed and has accurately reproduced the thermodynamic properties of pure substances including polar fluids. In this work we apply the equation to vapor‐liquid equilibrium calculations through the introduction of different mixing rules. Various classes of mixtures are investigated at low pressures as well as at high pressures. The calculated results show that the equation with the Huron‐Vidal mixing rules offers better correlations for all types of systems over a wide range of temperature and pressure.

Modeling phase behavior of carbon dioxide with aromatic solvents

“…The equation is vb u2 + ubv + wb2 where the parameters o, b, u, and w are functions of critical constants and the acentric factor, as shown in the Appendix. This equation has been applied successfully to a wide variety of phase equilibrium calculations (Jan and Tsai, 1990b).…”

High-Temperature Phase Equilibria for Asymmetric Mixtures of Helium + m-Xylene and Nitrogen + m-Xylene

“…Various cubic equations of state, which have been found to be accurate for calculations of the phase equilibrium for a diversity of mixtures, are applied in this work to correlate the new data of both helium + m-xylene and nitrogen + m-xylene. These equations include the Soave (SRK) (Soave, 1972), the Peng- Robinson (PR) (Peng and Robinson, 1976), the Patel-Teja (PT) (Patel and Teja, 1982), the Iwai-Margerum-Lu (IML) (Iwai et al, 1988), and the Jan-Tsai (JT) (Jan and Tsai, 1992). Table 3 summarizes the calculated K-values in percent deviation (absolute average deviation, AAD) from experimental results.…”

Phase Equilibria of Toluene in Mixtures with Helium or Nitrogen at High Temperatures

“…Five cubic equations of state were applied to represent the phase behavior for both mixtures: the Soave (SRK) (3), the Peng-Robinson (PR) (4), the Patel-Teja (PT) (5), the Iwai-Margerum-Lu (IML) (6), and the Jan-Tsai (JT) (7). All these equations adopted the traditional van der Waals one-fluid mixing rules for prediction of mixture equation where z¡ and z, are the mole fractions of the vapor or liquid phase for components i and j, respectively.…”

“…The equation constant u = 1.181 for helium as determined by this work, while u values for nitrogen and toluene were estimated from generalized correlation (6). g Jan and Tsai (7). Kg I while the adjustable interaction constant ky was determined for each equation, in eq 3 is the objective function used in the optimization for K values of component 1 (helium or nitrogen), Ki¿, and component 2 (toluene), K2,k, where the second subscript k corresponds to the number of the data point.…”