A new cubic equation of state for simple fluids: Pure and mixture

Kh Nasrifar, M. Moshfeghian

Research output: Contribution to journalArticlepeer-review

46 Citations (Scopus)


A two-parameter cubic equation of state is developed. Both parameters are taken temperature dependent. Methods are also suggested to calculate the attraction parameter and the co-volume parameter of this new equation of state. For calculating the thermodynamic properties of a pure compound, this equation of state requires the critical temperature, the critical pressure and the Pitzer's acentric factor of the component. Using this equation of state, the vapor pressure of pure compounds, especially near the critical point, and the bubble point pressure of binary mixtures are calculated accurately. The saturated liquid density of pure compounds and binary mixtures are also calculated quite accurately. The average of absolute deviations of the predicted vapor pressure, vapor volume and saturated liquid density of pure compounds are 1.18, 1.77 and 2.42%, respectively. Comparisons with other cubic equations of state for predicting some thermodynamic properties including second virial coefficients and thermal properties are given. Moreover, the capability of this equation of state for predicting the molar heat capacity of gases at constant pressure and the sound velocity in gases are also illustrated.

Original languageEnglish
Pages (from-to)73-88
Number of pages16
JournalFluid Phase Equilibria
Issue number1-2
Publication statusPublished - Nov 1 2001
Externally publishedYes


  • Equation of state
  • Mixture
  • Pure
  • Supercritical fluid
  • Thermal property
  • Volumetric property

ASJC Scopus subject areas

  • Chemical Engineering(all)
  • Physics and Astronomy(all)
  • Physical and Theoretical Chemistry

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