Simultaneous prediction of the critical and sub-critical phase behavior in mixtures using equations of state II. Carbon dioxide-heavy n-alkanes

Ilya Polishuk, Jaime Wisniak, Hugo Segura

Research output: Contribution to journalArticlepeer-review

42 Scopus citations

Abstract

In the present study we present the final development of the Global Phase Diagram-based semi-predictive approach (GPDA), which requires only 2-3 key data points of one homologue to predict the complete phase behavior of the whole homologues series. The ability of GPDA to predict phase equilibria in CO2-heavy n-alkanes is compared with the equations of state LCVM and PSRK. It is demonstrated that both LCVM and PSRK are more correlative rather than predictive because their parameters are evaluated by the local fit of a considerable amount of VLE experimental data. In addition, these models fail to predict accurately the VLE of systems, which have not been considered in the evaluation of their parameters. They are also particularly inaccurate in predicting LLE and critical lines. In contrast, GPDA is reliable in the entire temperature range and for all types of phase equilibria. It yields an accurate prediction of the global phase behavior in the homologues series and their critical lines. Moreover, increasing asymmetry does not affect the reliability of GPDA; it predicts very accurately even the data of the heaviest homologues of the series.

Original languageEnglish
Pages (from-to)2529-2550
Number of pages22
JournalChemical Engineering Science
Volume58
Issue number12
DOIs
StatePublished - Jun 2003
Externally publishedYes

Keywords

  • Alkanes
  • Carbon dioxide
  • Equation of state
  • Parameter identification
  • Phase equilibria
  • Supercritical fluid

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