JOURNAL OF CHEMICAL ENGINEERING OF JAPAN · 1993 · 27 citations · 17 references
Natural SciencesChemical EngineeringChemistryPhysical ChemistrySeparation ProcessesSeparation ScienceAqueous Two-phase SystemsMixing ThermodynamicsMixture ThermodynamicsPhase EquilibriaPhase SeparationSolvent ExtractionCarbon Dioxide SystemEquilibrium ModelsExtraction EquilibriaHelmholtz EquationTernary Phase EquilibriaThermodynamic AnalysisThermodynamics Of Aqueous SolutionsThermodynamics Of Extraction
Phase equilibria for the carbon dioxide-ethanol system and the carbon dioxide-ethanol-water system were measured to provide the thermodynamic base for the extraction of ethanol from its aqueous solutions using near-critical carbon dioxide as solvent. The experiments were carried out at 283 K–298 K and 5–7 MPa, including extraction conditions and solvent-recovery conditions in a wide range of ethanol concentration.An empirical mixing rule for the Helmholtz function with ternary as well as binary non-randomness parameters was proposed based on the density-dependent local composition concept. A correlation model was derived by a combination of the mixing rule with the Helmholtz function obtained from the Patel-Teja equation of state. The model successfully correlated the phase equilibria of the carbon dioxide-ethanol-water system.
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