Documents disponibles écrits par cet auteur

Catalytic conversion of syngas into higher alcohols over carbide catalysts / Jakob M. Christensen in Industrial & engineering chemistry research, Vol. 51 N° 11 (Mars 2012) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 51 N° 11 (Mars 2012) . - pp. 4161-4172 Titre : Catalytic conversion of syngas into higher alcohols over carbide catalysts Type de document : texte imprimé Auteurs : Jakob M. Christensen, Auteur ; Linus D. L. Duchstein, Auteur ; Jakob B. Wagner, Auteur Année de publication : 2012 Article en page(s) : pp. 4161-4172 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Catalyst  Synthesis  gas  Catalytic  conversion Résumé : This work investigates the use of the bulk carbides Mo2C, WC, and NbC as catalysts for the conversion of syngas into higher alcohols. K2CO3/WC produces mainly CH3OH and CH4 with a low activity. NbC has a very low activity in CO hydrogenation. K2CO3/Mo2C produces mixed alcohols with a reasonable activity and selectivity. In a 94 h test the activity and the specific surface area of the K2CO3/Mo2C catalyst decreased significantly, but X-ray diffraction and transmission electron microscopy did not indicate a strong sintering of the carbide. A likely cause for the deactivation is the formation of carbonaceous deposits on the catalyst. At the same general activity level Li, K, and Cs provide similar promotional effects for Mo2C, although K at a loading level of alkali metal/Mo = 0.164 mol/mol provides the better behavior at equal conditions. The effect of further additives on the K2CO3/Mo2C system was evaluated, but only Cu yielded an improvement. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25655624 [article] Catalytic conversion of syngas into higher alcohols over carbide catalysts [texte imprimé] / Jakob M. Christensen, Auteur ; Linus D. L. Duchstein, Auteur ; Jakob B. Wagner, Auteur . - 2012 . - pp. 4161-4172. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 11 (Mars 2012) . - pp. 4161-4172 Mots-clés : Catalyst  Synthesis  gas  Catalytic  conversion Résumé : This work investigates the use of the bulk carbides Mo2C, WC, and NbC as catalysts for the conversion of syngas into higher alcohols. K2CO3/WC produces mainly CH3OH and CH4 with a low activity. NbC has a very low activity in CO hydrogenation. K2CO3/Mo2C produces mixed alcohols with a reasonable activity and selectivity. In a 94 h test the activity and the specific surface area of the K2CO3/Mo2C catalyst decreased significantly, but X-ray diffraction and transmission electron microscopy did not indicate a strong sintering of the carbide. A likely cause for the deactivation is the formation of carbonaceous deposits on the catalyst. At the same general activity level Li, K, and Cs provide similar promotional effects for Mo2C, although K at a loading level of alkali metal/Mo = 0.164 mol/mol provides the better behavior at equal conditions. The effect of further additives on the K2CO3/Mo2C system was evaluated, but only Cu yielded an improvement. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25655624

Effects of feed composition and feed impurities in the catalytic conversion of syngas to higher alcohols over alkali-promoted cobalt-molybdenum sulfide / Jakob M. Christensen in Industrial & engineering chemistry research, Vol. 50 N° 13 (Juillet 2011) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 50 N° 13 (Juillet 2011) . - pp. 7949-7963 Titre : Effects of feed composition and feed impurities in the catalytic conversion of syngas to higher alcohols over alkali-promoted cobalt-molybdenum sulfide Type de document : texte imprimé Auteurs : Jakob M. Christensen, Auteur ; Peter A. Jensen, Auteur ; Anker D. Jensen, Auteur Année de publication : 2011 Article en page(s) : pp. 7949-7963 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Synthesis  gas  Catalytic  conversion  Impurity Résumé : Alkali-promoted cobalt-molybdenum sulfide is a potential catalyst for the conversion of syngas into higher alcohols. This work is an investigation of how the feed composition influences the behavior of the sulfide catalyst. In a sulfur-free syngas the production of higher alcohols is observed to be optimal with an equimolar mixture of CO and H2 in the feed, while the methanol production benefits from an increasing hydrogen content in the feed. The influence of NH3 and H2O in the syngas feed has also been investigated. Ammonia (741 ppmv) in the feed is observed to cause a general and largely reversible deactivation of the catalyst. Operation with elevated water levels in the syngas feed (4.7-13.4 mol %) is observed to cause a deactivation of the catalyst, and it is especially the chain growth that is affected. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24332119 [article] Effects of feed composition and feed impurities in the catalytic conversion of syngas to higher alcohols over alkali-promoted cobalt-molybdenum sulfide [texte imprimé] / Jakob M. Christensen, Auteur ; Peter A. Jensen, Auteur ; Anker D. Jensen, Auteur . - 2011 . - pp. 7949-7963. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 50 N° 13 (Juillet 2011) . - pp. 7949-7963 Mots-clés : Synthesis  gas  Catalytic  conversion  Impurity Résumé : Alkali-promoted cobalt-molybdenum sulfide is a potential catalyst for the conversion of syngas into higher alcohols. This work is an investigation of how the feed composition influences the behavior of the sulfide catalyst. In a sulfur-free syngas the production of higher alcohols is observed to be optimal with an equimolar mixture of CO and H2 in the feed, while the methanol production benefits from an increasing hydrogen content in the feed. The influence of NH3 and H2O in the syngas feed has also been investigated. Ammonia (741 ppmv) in the feed is observed to cause a general and largely reversible deactivation of the catalyst. Operation with elevated water levels in the syngas feed (4.7-13.4 mol %) is observed to cause a deactivation of the catalyst, and it is especially the chain growth that is affected. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24332119