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Gas phase oxidation of iso-butylene over bismuth molybdate based catalysts / Farid Benyahia 

Public ISBD Titre : Gas phase oxidation of iso-butylene over bismuth molybdate based catalysts Type de document : texte imprimé Auteurs : Farid Benyahia, Auteur ; A. M. Mearns, Directeur de thèse Editeur : Newcastle [England] : [s.n.] Année de publication : 1985 Importance : 161 f. Présentation : ill. Format : 30 cm. Note générale : Master thesis : Chemical Engineering : University of Newcastle Upon Tyne : 1985 Annexe f. 162 - 209 Langues : Anglais (eng) Mots-clés : Gas  phase  oxidation Isobutylene Silica  supported Tubular  flow  reactor On-line  gas  chromatography Surface  area  measurements X-ray  diffraction Index. décimale : Ms00385 Résumé : The selective vapour phase oxidation of hydrocarbons is an important method of synthesising valuable industrial organic intermediates destined to the manufacture of plastics, resins, lacquers and preservatives. Mixed oxides of transition metals have found wide application as catalysts in this respect. In recent years, thorough investigations of mechanistic and kinetic aspects of oxidation and ammoxidation processes have led to a greater understanding of how the above mentioned catalysts function. Beacause the oxidation and ammoxidation of propylene found commercial applications, the attention of research workers has been particularly focused on the catalytic oxidation and ammoxidation of that hydrocarbon on metal oxides, in particular on bismuth molybdate based catalysts. Bismuth molybdate based catalysts are known to be used in major commercial processes for the production of acrolein and acrylonitrile. In the present work, the kinetics of the gas phase oxidation of isobutylene over ϒ-bismuth molybdate (Bi₂O₃.MoO₃), multicomponent molybdate (Ni₈Cr₃BiMo₁₂On) and silica supported ϒ-bismuth molybdate were investigated in a differential tubular flow reactor over the temperature range (608-730 K) at a pressure of 101.33 kN m⁻² (1 atm) and the products were analysed by on-line gas chromatography. The catalysts employed were prepared by the co-precipitation and evaporation method and were characterised by suface area measurements and powder X-ray diffraction. Methacrolein and carbon dioxide were the sole products detected on the three types of catalysts, although traces of carbon monoxide were observed at low temperatures. All of the three types of catalysts were active and selective, however, the multicomponent molybdate was found to have the highest activity at temperatures in excess of 663 K. The supported bismuth molybdate was the best choice for reaction control as the carrier helped dissipate the heat of reaction. Gas phase oxidation of iso-butylene over bismuth molybdate based catalysts [texte imprimé] / Farid Benyahia, Auteur ; A. M. Mearns, Directeur de thèse . - Newcastle (England) : [s.n.], 1985 . - 161 f. : ill. ; 30 cm. Master thesis : Chemical Engineering : University of Newcastle Upon Tyne : 1985 Annexe f. 162 - 209 Langues : Anglais (eng) Mots-clés : Gas  phase  oxidation Isobutylene Silica  supported Tubular  flow  reactor On-line  gas  chromatography Surface  area  measurements X-ray  diffraction Index. décimale : Ms00385 Résumé : The selective vapour phase oxidation of hydrocarbons is an important method of synthesising valuable industrial organic intermediates destined to the manufacture of plastics, resins, lacquers and preservatives. Mixed oxides of transition metals have found wide application as catalysts in this respect. In recent years, thorough investigations of mechanistic and kinetic aspects of oxidation and ammoxidation processes have led to a greater understanding of how the above mentioned catalysts function. Beacause the oxidation and ammoxidation of propylene found commercial applications, the attention of research workers has been particularly focused on the catalytic oxidation and ammoxidation of that hydrocarbon on metal oxides, in particular on bismuth molybdate based catalysts. Bismuth molybdate based catalysts are known to be used in major commercial processes for the production of acrolein and acrylonitrile. In the present work, the kinetics of the gas phase oxidation of isobutylene over ϒ-bismuth molybdate (Bi₂O₃.MoO₃), multicomponent molybdate (Ni₈Cr₃BiMo₁₂On) and silica supported ϒ-bismuth molybdate were investigated in a differential tubular flow reactor over the temperature range (608-730 K) at a pressure of 101.33 kN m⁻² (1 atm) and the products were analysed by on-line gas chromatography. The catalysts employed were prepared by the co-precipitation and evaporation method and were characterised by suface area measurements and powder X-ray diffraction. Methacrolein and carbon dioxide were the sole products detected on the three types of catalysts, although traces of carbon monoxide were observed at low temperatures. All of the three types of catalysts were active and selective, however, the multicomponent molybdate was found to have the highest activity at temperatures in excess of 663 K. The supported bismuth molybdate was the best choice for reaction control as the carrier helped dissipate the heat of reaction.

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité	Spécialité	Etat_Exemplaire
Ms00385	Ms00385	Papier	Bibliothèque centrale	Mémoire de Master	Disponible		Consultation sur place

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