paper

  Improving Cubic Equations of State

  for Polar Fluids

  F. Feyzi , H. R. Rahdar

  Abstract

  Feyzi-Riazi equation of state[1] (FR-EOS) is modified in this paper. FR equation ofstate which is a modification of Peng-Robinson equation of state[2] (PR-EOS) predicts the volume of both liquid and vapor phases of nonpolar compounds accurately. But it fails in the prediction of the behavior of polar compounds.

  In addition to the reduced dipole moment the proposed equation requires critical temperat-ure, critical pressure and acentric factor as the input parameters. The proposed equation of state estimates the specific volume of polar liquids and hydrogen-bonded fluids with greater accu-racy while maintaining the ability of the FR-EOS in predicting vapor pressure and critical com-pressibility factor of pure compounds and mixtures.