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Hydrogenation of 2-butyne-1,4-diol using novel bio-palladium catalysts / Joseph Wood in Industrial & engineering chemistry research, Vol. 49 N° 3 (Fevrier 2010) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 49 N° 3 (Fevrier 2010) . - pp. 980–988 Titre : Hydrogenation of 2-butyne-1,4-diol using novel bio-palladium catalysts Type de document : texte imprimé Auteurs : Joseph Wood, Auteur ; Lucille Bodenes, Auteur ; James Bennett, Auteur Année de publication : 2010 Article en page(s) : pp. 980–988 Note générale : Industrial Chemistry Langues : Anglais (eng) Mots-clés : Hydrogenation--Butyne--diol--Catalysts--  Novel--Bio-Palladium Résumé : Palladium catalyst samples were prepared upon bacterial biomass supports (Gram-positive A. oxidans and Gram-negative R. capsulatus) and tested in the partial hydrogenation of 2-butyne-1,4-diol to 2-butene-1,4-diol. The objectives of the study were to assess the effects of operating conditions in the stirred autoclave upon the reaction conversion and selectivity and to compare the biologically supported palladium (BioPd) catalyst performance with that of a conventionally supported catalyst. Variables investigated included solvent, stirring speed, and catalyst metal loading. A maximum selectivity toward 2-butene-1,4-diol of 0.98 was observed in a solvent composed of 5% isopropyl alcohol (2-propanol) in water at a conversion of 75% 2-butyne-1,4-diol for the Pd/A. oxidans catalyst. The Pd/R.capsulatas catalyst showed a maximum selectivity of 1.0 at a conversion of 62.6%. Concentration profiles of the different hydrogenation products were fitted using a Langmuir−Hinshelwood expression, which showed a higher fitted adsorption constant of 2-butyne-1,4-diol in a 5% 2-propanol/water solvent, compared with pure 2-propanol, suggesting that adsorption is stronger in the mixed solvent. At a typical catalyst loading of 0.29 g/L (Pd/R. capsulatus), analysis of the mass-transfer steps in the reactor showed that 63% of the resistance to mass transfer lies at the catalyst (liquid−solid) particle and 37% lies at the gas bubble interface. BioPd was proven to be a highly selective catalyst for partial hydrogenation reactions and has the advantage that it can be prepared inexpensively from metal-waste-bearing solutions. Note de contenu : Bibiogr. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900663k [article] Hydrogenation of 2-butyne-1,4-diol using novel bio-palladium catalysts [texte imprimé] / Joseph Wood, Auteur ; Lucille Bodenes, Auteur ; James Bennett, Auteur . - 2010 . - pp. 980–988. Industrial Chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 3 (Fevrier 2010) . - pp. 980–988 Mots-clés : Hydrogenation--Butyne--diol--Catalysts--  Novel--Bio-Palladium Résumé : Palladium catalyst samples were prepared upon bacterial biomass supports (Gram-positive A. oxidans and Gram-negative R. capsulatus) and tested in the partial hydrogenation of 2-butyne-1,4-diol to 2-butene-1,4-diol. The objectives of the study were to assess the effects of operating conditions in the stirred autoclave upon the reaction conversion and selectivity and to compare the biologically supported palladium (BioPd) catalyst performance with that of a conventionally supported catalyst. Variables investigated included solvent, stirring speed, and catalyst metal loading. A maximum selectivity toward 2-butene-1,4-diol of 0.98 was observed in a solvent composed of 5% isopropyl alcohol (2-propanol) in water at a conversion of 75% 2-butyne-1,4-diol for the Pd/A. oxidans catalyst. The Pd/R.capsulatas catalyst showed a maximum selectivity of 1.0 at a conversion of 62.6%. Concentration profiles of the different hydrogenation products were fitted using a Langmuir−Hinshelwood expression, which showed a higher fitted adsorption constant of 2-butyne-1,4-diol in a 5% 2-propanol/water solvent, compared with pure 2-propanol, suggesting that adsorption is stronger in the mixed solvent. At a typical catalyst loading of 0.29 g/L (Pd/R. capsulatus), analysis of the mass-transfer steps in the reactor showed that 63% of the resistance to mass transfer lies at the catalyst (liquid−solid) particle and 37% lies at the gas bubble interface. BioPd was proven to be a highly selective catalyst for partial hydrogenation reactions and has the advantage that it can be prepared inexpensively from metal-waste-bearing solutions. Note de contenu : Bibiogr. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900663k

Selective hydrogenation of 1 - heptyne in a mini trickle bed reactor / Mansour Al-Herz in Industrial & engineering chemistry research, Vol. 51 N° 26 (Juillet 2012) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 51 N° 26 (Juillet 2012) . - pp. 8815-8825 Titre : Selective hydrogenation of 1 - heptyne in a mini trickle bed reactor Type de document : texte imprimé Auteurs : Mansour Al-Herz, Auteur ; Mark J. H. Simmons, Auteur ; Joseph Wood, Auteur Année de publication : 2012 Article en page(s) : pp. 8815-8825 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Trickle  bed  reactor  Hydrogenation Résumé : The selective hydrogenation of 1-heptyne over a 2 wt % Pd/Al2O3 catalyst was studied in a trickle bed reactor operating in both batch recycle and continuous modes. The reaction was studied in a range of different solvents, including isopropanol, hexane, mixtures of these two solvents, and also isopropanol with small quantities of water and base (NaOH) added. It was found that the rate of reaction was fastest in hexane, owing to the higher hydrogen solubility in this solvent. However, the selectivity toward 1-heptene was higher in isopropanol, with over 95% selectivity being maintained for 120 min of the total 240 min reaction time. The addition of water or base led to an increase in reaction rate, possibly through modification of the adsorption equilibria at the catalyst surface or direct involvement in the reaction. The hydrodynamics of trickle flow upon the reaction were investigated, showing that increasing liquid flow rate led to enhancement of reaction rate, although a plateau was eventually reached at the higher flows. The higher flows led to improved catalyst wetting, liquid hold up, and mass transfer rates, thus explaining the enhanced reaction rate. The concentration profiles were fitted according to a Langmuir―Hinshelwood kinetic expression. Operation in continuous flow was demonstrated, although a long residence time was required for high conversion, leading to lower 1-heptene selectivity compared with batch recycle operation. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26107435 [article] Selective hydrogenation of 1 - heptyne in a mini trickle bed reactor [texte imprimé] / Mansour Al-Herz, Auteur ; Mark J. H. Simmons, Auteur ; Joseph Wood, Auteur . - 2012 . - pp. 8815-8825. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 26 (Juillet 2012) . - pp. 8815-8825 Mots-clés : Trickle  bed  reactor  Hydrogenation Résumé : The selective hydrogenation of 1-heptyne over a 2 wt % Pd/Al2O3 catalyst was studied in a trickle bed reactor operating in both batch recycle and continuous modes. The reaction was studied in a range of different solvents, including isopropanol, hexane, mixtures of these two solvents, and also isopropanol with small quantities of water and base (NaOH) added. It was found that the rate of reaction was fastest in hexane, owing to the higher hydrogen solubility in this solvent. However, the selectivity toward 1-heptene was higher in isopropanol, with over 95% selectivity being maintained for 120 min of the total 240 min reaction time. The addition of water or base led to an increase in reaction rate, possibly through modification of the adsorption equilibria at the catalyst surface or direct involvement in the reaction. The hydrodynamics of trickle flow upon the reaction were investigated, showing that increasing liquid flow rate led to enhancement of reaction rate, although a plateau was eventually reached at the higher flows. The higher flows led to improved catalyst wetting, liquid hold up, and mass transfer rates, thus explaining the enhanced reaction rate. The concentration profiles were fitted according to a Langmuir―Hinshelwood kinetic expression. Operation in continuous flow was demonstrated, although a long residence time was required for high conversion, leading to lower 1-heptene selectivity compared with batch recycle operation. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26107435