## Abstract

We modified the binary interaction parameter in Wong-Sandler mixing rule for cubic EOS as a two-parameter linear function of composition. We then incorporated the Non-Random-Two-Liquid excess Gibbs energy model into the modified Wong-Sandler mixing rule to correlate the phase boundaries of the CO_{2}-H_{2}O system through the φ-φ approach by using Peng-Robinson-Stryjek-Vera equation of state. The proposed EOS/G^{ex} model has four adjustable temperature-dependent parameters for polar molecules; and it can be reduced smoothly to the van der Waal one-fluid mixing rule with only one binary interaction parameter for hydrocarbon systems. An excellent result was obtained when compared the modeling results with a large amount of the vapor-liquid equilibria experimental data (more than 1300 experimental data points located in a P-T region of 273-623 K and 0.1-200 MPa) for the CO_{2}-H_{2}O system. The average absolute deviations (AAD%) of modeling results from experimental data (mutual solubilities of CO_{2} and H_{2}O) are less than 7.5% for both phases. In addition, the proposed model can be easily extended to a multi-component system on condition that the binary interaction parameters of each binary pair in the multi-component system are known. We provided a calculation example for the ternary CO_{2}-CH_{4}-H_{2}O system and found that the modeling result agrees very well with experimental data for this ternary system.

Original language | English (US) |
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Pages (from-to) | 96-108 |

Number of pages | 13 |

Journal | Fluid Phase Equilibria |

Volume | 417 |

DOIs | |

State | Published - Jun 15 2016 |

## All Science Journal Classification (ASJC) codes

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