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Characterizing lactic acid hydrogenolysis rates in laboratory trickle bed reactors / Yaoyan Xi in Industrial & engineering chemistry research, Vol. 50 N° 9 (Mai 2011) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 50 N° 9 (Mai 2011) . - pp. 5440-5447 Titre : Characterizing lactic acid hydrogenolysis rates in laboratory trickle bed reactors Type de document : texte imprimé Auteurs : Yaoyan Xi, Auteur ; James E. Jackson, Auteur ; Dennis J. Miller, Auteur Année de publication : 2011 Article en page(s) : pp. 5440-5447 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Trickle  bed  reactor  Hydrogenolysis Résumé : Representative reaction kinetics are difficult to obtain in mutiphase laboratory trickle bed reactors, particularly when the gaseous reactant is rate-limiting, because of mass transport resistances and reactor hydrodynamics in the trickle bed regime. The ruthenium-catalyzed hydrogenolysis of lactic acid to propylene glycol has been examined in trickle bed and batch reactors to better understand the influence of mass transfer and partial wetting and to identify operating conditions where intrinsic kinetic rates can be obtained. At high liquid flow rates and low conversions in the trickle bed reactor, propylene glycol formation rates agree well with intrinsic rates obtained in a stirred batch reactor, with rate independent of feed flow rate or bed configuration in the trickle bed reactor. Application of a mass transport model to the trickle bed reactor at lower flow rates allows rates to be predicted outside the intrinsic kinetic regime. These results provide guidance for proper operation oflaboratory trickle bed reactors and make it possible to predict performance in a trickle-bed reactor based on experiments conducted in bench-scale batch reactors. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24128666 [article] Characterizing lactic acid hydrogenolysis rates in laboratory trickle bed reactors [texte imprimé] / Yaoyan Xi, Auteur ; James E. Jackson, Auteur ; Dennis J. Miller, Auteur . - 2011 . - pp. 5440-5447. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 50 N° 9 (Mai 2011) . - pp. 5440-5447 Mots-clés : Trickle  bed  reactor  Hydrogenolysis Résumé : Representative reaction kinetics are difficult to obtain in mutiphase laboratory trickle bed reactors, particularly when the gaseous reactant is rate-limiting, because of mass transport resistances and reactor hydrodynamics in the trickle bed regime. The ruthenium-catalyzed hydrogenolysis of lactic acid to propylene glycol has been examined in trickle bed and batch reactors to better understand the influence of mass transfer and partial wetting and to identify operating conditions where intrinsic kinetic rates can be obtained. At high liquid flow rates and low conversions in the trickle bed reactor, propylene glycol formation rates agree well with intrinsic rates obtained in a stirred batch reactor, with rate independent of feed flow rate or bed configuration in the trickle bed reactor. Application of a mass transport model to the trickle bed reactor at lower flow rates allows rates to be predicted outside the intrinsic kinetic regime. These results provide guidance for proper operation oflaboratory trickle bed reactors and make it possible to predict performance in a trickle-bed reactor based on experiments conducted in bench-scale batch reactors. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24128666

Hydrogenation of amino acid mixtures to amino alcohols / Ketan P. Pimparkar in Industrial & engineering chemistry research, Vol. 47 N°20 (Octobre 2008) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 47 N°20 (Octobre 2008) . - P. 7648-7653 Titre : Hydrogenation of amino acid mixtures to amino alcohols Type de document : texte imprimé Auteurs : Ketan P. Pimparkar, Editeur scientifique ; Dennis J. Miller, Editeur scientifique ; James E. Jackson, Editeur scientifique Année de publication : 2008 Article en page(s) : P. 7648-7653 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : Amino  acid  Amino  alcohols Résumé : Amino alcohols are important building blocks for a variety of pharmaceutical, insecticidal, and other specialty compounds. Hydrogenation of amino acids to amino alcohols is a route that allows for the incorporation of biorenewable-derived chemicals into traditional petroleum-based industrial processes. This study examines the effect of multiple substrates on aqueous-phase hydrogenation rates of the amino acids serine, alanine, and valine. Hydrogenation reactions were carried out in a high-pressure reactor at 7.0 MPa hydrogen pressure and 130 °C over carbon supported ruthenium catalyst. Samples taken at regular intervals and analyzed by high-performance liquid chromatography allowed calculation of conversion rates and product yields. In general, competition between the amino acid substrates results in reduced reaction rates relative to that for hydrogenation of a single amino acid substrate. Kinetics of mixed amino acid hydrogenation was modeled using a Langmuir−Hinshelwood-type mechanism with surface reaction as the rate-limiting step. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800351x [article] Hydrogenation of amino acid mixtures to amino alcohols [texte imprimé] / Ketan P. Pimparkar, Editeur scientifique ; Dennis J. Miller, Editeur scientifique ; James E. Jackson, Editeur scientifique . - 2008 . - P. 7648-7653. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N°20 (Octobre 2008) . - P. 7648-7653 Mots-clés : Amino  acid  Amino  alcohols Résumé : Amino alcohols are important building blocks for a variety of pharmaceutical, insecticidal, and other specialty compounds. Hydrogenation of amino acids to amino alcohols is a route that allows for the incorporation of biorenewable-derived chemicals into traditional petroleum-based industrial processes. This study examines the effect of multiple substrates on aqueous-phase hydrogenation rates of the amino acids serine, alanine, and valine. Hydrogenation reactions were carried out in a high-pressure reactor at 7.0 MPa hydrogen pressure and 130 °C over carbon supported ruthenium catalyst. Samples taken at regular intervals and analyzed by high-performance liquid chromatography allowed calculation of conversion rates and product yields. In general, competition between the amino acid substrates results in reduced reaction rates relative to that for hydrogenation of a single amino acid substrate. Kinetics of mixed amino acid hydrogenation was modeled using a Langmuir−Hinshelwood-type mechanism with surface reaction as the rate-limiting step. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800351x