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First-principles predictions of vapor-liquid equilibria for pure and mixture fluids from the combined use of cubic equations of state and solvation calculations / Chieh-Ming Hsieh in Industrial & engineering chemistry research, Vol. 48 N° 6 (Mars 2009) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 48 N° 6 (Mars 2009) . - pp. 3197–3205 Titre : First-principles predictions of vapor-liquid equilibria for pure and mixture fluids from the combined use of cubic equations of state and solvation calculations Type de document : texte imprimé Auteurs : Chieh-Ming Hsieh, Auteur ; Shiang-Tai Lin, Auteur Année de publication : 2009 Article en page(s) : pp. 3197–3205 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : Cubic  equations  of  state  Phase  equilibria  Pure  fluids  Mixture  fluids Résumé : A novel approach combining first-principles solvation calculations and cubic equations of state is proposed for the prediction of phase equilibria of both pure and mixture fluids. The temperature and composition dependence of the energy parameter, a(T,x), in the EOS is determined from the attractive contribution to the solvation free energy. The volume parameter, b(x), is estimated to be the mole-fraction-weighted average volume of the molecular solvation cavity. This approach does not require the input of any experimental data (e.g., critical properties or acentric factor) for pure components and does not presume any composition dependence of the energy parameter. The Peng−Robinson EOS combined with a solvation model based on COSMO-SAC calculations, denoted as PR+COSMOSAC, is used to illustrate the applicability of this approach. It is found that the relative error from PR+COSMOSAC is 48% in vapor pressure, 21% in liquid density at the normal boiling point, 10% in critical pressure, 4% in critical temperature, and 5% in critical volume for 1295 pure substances and 27.56% in pressure and 5.18% in vapor-phase composition for 116 binary mixtures in vapor−liquid equilibrium. The errors in binary mixtures can be reduced significantly to 6.24% and 2.25% if experimental vapor pressures are used to correct for any errors in the calculated charging free energies of pure species. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801118a [article] First-principles predictions of vapor-liquid equilibria for pure and mixture fluids from the combined use of cubic equations of state and solvation calculations [texte imprimé] / Chieh-Ming Hsieh, Auteur ; Shiang-Tai Lin, Auteur . - 2009 . - pp. 3197–3205. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 6 (Mars 2009) . - pp. 3197–3205 Mots-clés : Cubic  equations  of  state  Phase  equilibria  Pure  fluids  Mixture  fluids Résumé : A novel approach combining first-principles solvation calculations and cubic equations of state is proposed for the prediction of phase equilibria of both pure and mixture fluids. The temperature and composition dependence of the energy parameter, a(T,x), in the EOS is determined from the attractive contribution to the solvation free energy. The volume parameter, b(x), is estimated to be the mole-fraction-weighted average volume of the molecular solvation cavity. This approach does not require the input of any experimental data (e.g., critical properties or acentric factor) for pure components and does not presume any composition dependence of the energy parameter. The Peng−Robinson EOS combined with a solvation model based on COSMO-SAC calculations, denoted as PR+COSMOSAC, is used to illustrate the applicability of this approach. It is found that the relative error from PR+COSMOSAC is 48% in vapor pressure, 21% in liquid density at the normal boiling point, 10% in critical pressure, 4% in critical temperature, and 5% in critical volume for 1295 pure substances and 27.56% in pressure and 5.18% in vapor-phase composition for 116 binary mixtures in vapor−liquid equilibrium. The errors in binary mixtures can be reduced significantly to 6.24% and 2.25% if experimental vapor pressures are used to correct for any errors in the calculated charging free energies of pure species. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801118a