Documents disponibles écrits par cet auteur

Coke formation in the transfer line exchanger during steam cracking of hydrocarbons / Kevin M. Van Geem in Industrial & engineering chemistry research, Vol. 48 N° 23 (Décembre 2009) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10343–10358 Titre : Coke formation in the transfer line exchanger during steam cracking of hydrocarbons Type de document : texte imprimé Auteurs : Kevin M. Van Geem, Auteur ; Inge Dhuyvetter, Auteur ; Serge Prokopiev, Auteur Année de publication : 2010 Article en page(s) : pp. 10343–10358 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Coke  Formation--Transfer--Line  Exchanger--during  Steam--Cracking  --Hydrocarbons Résumé : Coke formation under transfer line exchanger conditions, that is, at temperatures from 623 to 873 K and atmospheric pressure, is studied in an electrobalance setup. The coking rate is initially very high (catalytic coking) and drops after a few hours to a constant value. At the studied conditions the observed coking behavior on 15Mo3 alloy pigs can be explained via a catalytic mechanism only, and contributions of the free-radical mechanism and the condensation mechanism are insignificant. Experiments with ethane and naphtha steam cracking effluents and with well-defined reaction mixtures show that the coking rate is independent of the partial pressure of ethene (0−2.7 × 104 Pa), ortho-xylene (0−1.0 × 104 Pa), heavy aromatic hydrocarbons (0−3.0 × 102 Pa), and also 1,3-butadiene (0−2.7 × 104 Pa). The rate of coke deposition depends only on the temperature and the ratio of the partial pressures of water to dihydrogen. The activation energy for initial coke formation was estimated to be ∼90 kJ/mol, a value close to the experimentally determined diffusion energy of carbon in iron. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900124z [article] Coke formation in the transfer line exchanger during steam cracking of hydrocarbons [texte imprimé] / Kevin M. Van Geem, Auteur ; Inge Dhuyvetter, Auteur ; Serge Prokopiev, Auteur . - 2010 . - pp. 10343–10358. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10343–10358 Mots-clés : Coke  Formation--Transfer--Line  Exchanger--during  Steam--Cracking  --Hydrocarbons Résumé : Coke formation under transfer line exchanger conditions, that is, at temperatures from 623 to 873 K and atmospheric pressure, is studied in an electrobalance setup. The coking rate is initially very high (catalytic coking) and drops after a few hours to a constant value. At the studied conditions the observed coking behavior on 15Mo3 alloy pigs can be explained via a catalytic mechanism only, and contributions of the free-radical mechanism and the condensation mechanism are insignificant. Experiments with ethane and naphtha steam cracking effluents and with well-defined reaction mixtures show that the coking rate is independent of the partial pressure of ethene (0−2.7 × 104 Pa), ortho-xylene (0−1.0 × 104 Pa), heavy aromatic hydrocarbons (0−3.0 × 102 Pa), and also 1,3-butadiene (0−2.7 × 104 Pa). The rate of coke deposition depends only on the temperature and the ratio of the partial pressures of water to dihydrogen. The activation energy for initial coke formation was estimated to be ∼90 kJ/mol, a value close to the experimentally determined diffusion energy of carbon in iron. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900124z

Modeling the composition of crude oil fractions using constrained homologous series / Steven P. Pyl in Industrial & engineering chemistry research, Vol. 50 N° 18 (Septembre 2011) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 50 N° 18 (Septembre 2011) . - pp. 10850-10858 Titre : Modeling the composition of crude oil fractions using constrained homologous series Type de document : texte imprimé Auteurs : Steven P. Pyl, Auteur ; Zhen Hou, Auteur ; Kevin M. Van Geem, Auteur Année de publication : 2011 Article en page(s) : pp. 10850-10858 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Crude  oil  Modeling Résumé : Composition anodeling using coastrained homologous series permits the derivation of the detailed composition of complex mixtures starting from a limited set of mixture bulk properties. By imposing various constraints, the number of unknowns is drastically reduced. Probability density functions are imposed on both the carbon number distribution in each homologous series of components and on the structural attribute distributions. Validation, based on detailed compositional information, shows that the use of gamma distributions to constrain the mixture composition results in an adequate approximation of the experimentally measured composition. The latter was obtained for two middle distillates and a heavy gas oil using advanced analytical techniques. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24523902 [article] Modeling the composition of crude oil fractions using constrained homologous series [texte imprimé] / Steven P. Pyl, Auteur ; Zhen Hou, Auteur ; Kevin M. Van Geem, Auteur . - 2011 . - pp. 10850-10858. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 50 N° 18 (Septembre 2011) . - pp. 10850-10858 Mots-clés : Crude  oil  Modeling Résumé : Composition anodeling using coastrained homologous series permits the derivation of the detailed composition of complex mixtures starting from a limited set of mixture bulk properties. By imposing various constraints, the number of unknowns is drastically reduced. Probability density functions are imposed on both the carbon number distribution in each homologous series of components and on the structural attribute distributions. Validation, based on detailed compositional information, shows that the use of gamma distributions to constrain the mixture composition results in an adequate approximation of the experimentally measured composition. The latter was obtained for two middle distillates and a heavy gas oil using advanced analytical techniques. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24523902