Documents disponibles écrits par cet auteur

Application of COSMO-RS type models to the prediction of excess enthalpies / Dana Constantinescu in Industrial & engineering chemistry research, Vol. 48 N° 18 (Septembre 2009) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 48 N° 18 (Septembre 2009) . - pp. 8710–8725 Titre : Application of COSMO-RS type models to the prediction of excess enthalpies Type de document : texte imprimé Auteurs : Dana Constantinescu, Auteur ; Jürgen Rarey, Auteur ; Jürgen Gmehling, Auteur Année de publication : 2010 Article en page(s) : pp. 8710–8725 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : COSMO-SAC  models  COSMO-RS(Ol)  models  Excess  enthalpies  Binary  systems Résumé : This article presents a comparative study about the predictive capability of COSMO-SAC and COSMO-RS(Ol) models with respect to excess enthalpies of various binary systems. Results of the group contribution methods UNIFAC and modified UNIFAC (Do) are given for comparison. COSMO calculations were performed using σ profiles based on density functional theory (BP and B3LYP). These were generated by the quantum chemical programs Turbomole and Gaussian 03, with the basis sets used for the calculation being triple-ζ valence polarization (TZVP) for BP and 6-311G(d,p) in the case of B3LYP. All results are compared with experimental data stored in the Dortmund Data Bank for 10 851 binary data sets (5368 different binary mixtures) with over 165 000 experimental data points from nearly 2000 references and are analyzed according to the types of components in the mixture. As expected, the intensively trained mod. UNIFAC (Do) model performs best in predicting the excess enthalpy of binary systems in most cases, but also COSMO-RS type models often lead to astonishingly good results considering the very small number of parameters used. Overall, relative deviations for a common data set of 30.7% (mod. UNIFAC (Do)) and between 56.7% and 80.8% for the different COSMO-RS flavors were obtained. Whenever experimental data indicated a significant change of the excess enthalpy with temperature, the different COSMO-RS type models failed to reproduce this behavior. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900315p [article] Application of COSMO-RS type models to the prediction of excess enthalpies [texte imprimé] / Dana Constantinescu, Auteur ; Jürgen Rarey, Auteur ; Jürgen Gmehling, Auteur . - 2010 . - pp. 8710–8725. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 18 (Septembre 2009) . - pp. 8710–8725 Mots-clés : COSMO-SAC  models  COSMO-RS(Ol)  models  Excess  enthalpies  Binary  systems Résumé : This article presents a comparative study about the predictive capability of COSMO-SAC and COSMO-RS(Ol) models with respect to excess enthalpies of various binary systems. Results of the group contribution methods UNIFAC and modified UNIFAC (Do) are given for comparison. COSMO calculations were performed using σ profiles based on density functional theory (BP and B3LYP). These were generated by the quantum chemical programs Turbomole and Gaussian 03, with the basis sets used for the calculation being triple-ζ valence polarization (TZVP) for BP and 6-311G(d,p) in the case of B3LYP. All results are compared with experimental data stored in the Dortmund Data Bank for 10 851 binary data sets (5368 different binary mixtures) with over 165 000 experimental data points from nearly 2000 references and are analyzed according to the types of components in the mixture. As expected, the intensively trained mod. UNIFAC (Do) model performs best in predicting the excess enthalpy of binary systems in most cases, but also COSMO-RS type models often lead to astonishingly good results considering the very small number of parameters used. Overall, relative deviations for a common data set of 30.7% (mod. UNIFAC (Do)) and between 56.7% and 80.8% for the different COSMO-RS flavors were obtained. Whenever experimental data indicated a significant change of the excess enthalpy with temperature, the different COSMO-RS type models failed to reproduce this behavior. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900315p