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Hydroisomerization of n-heptane over Pt-loaded USY zeolites. effect of steaming, dealumination, and the resulting structure on catalytic properties / Raed H. Abudawood in Industrial & engineering chemistry research, Vol. 50 N° 17 (Septembre 2011) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 50 N° 17 (Septembre 2011) . - pp. 9918-9924 Titre : Hydroisomerization of n-heptane over Pt-loaded USY zeolites. effect of steaming, dealumination, and the resulting structure on catalytic properties Type de document : texte imprimé Auteurs : Raed H. Abudawood, Auteur ; Faisal M. Alotaibi, Auteur ; Arthur A. Garforth, Auteur Année de publication : 2011 Article en page(s) : pp. 9918-9924 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Catalytic  reaction  Zeolite  Hydrotreatin  Isomerization Résumé : The hydroconversion of n-heptane was studied on five USY zeolite samples loaded with 1 wt%Pt. Experiments were performed on a continuous fixed-bed stainless steel reactor at 210-310 °C and pressures up to 15 bar. Three in-house samples were subjected to steaming treatment, and the remaining were acid-leached from a commercial source. The study aimed to evaluate the effect of acid leaching, and its subsequent extraframework alumina (EFAL) species removal, on the performance of bifunctional USY zeolite catalysts during n-heptane transformation. Results have shown that steamed samples generate more cracked products at higher conversions when compared to acid-leached ones, more than likely due to a high presence of EFAL species. The degree of steaming played a role in decreasing cracking tendency at higher pressures, which is attributed to pore structure change and decreasing acidity. In addition, steaming resulted in a catalyst sample capable of generating isomers with blended research octane numbers dose to those achieved with a robust commercial catalyst. However, poisoning experiments have shown that these two catalysts are highly sensitive to sulfur and require sulfur-free feeds in order to demonstrate their full capacities. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24483635 [article] Hydroisomerization of n-heptane over Pt-loaded USY zeolites. effect of steaming, dealumination, and the resulting structure on catalytic properties [texte imprimé] / Raed H. Abudawood, Auteur ; Faisal M. Alotaibi, Auteur ; Arthur A. Garforth, Auteur . - 2011 . - pp. 9918-9924. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 50 N° 17 (Septembre 2011) . - pp. 9918-9924 Mots-clés : Catalytic  reaction  Zeolite  Hydrotreatin  Isomerization Résumé : The hydroconversion of n-heptane was studied on five USY zeolite samples loaded with 1 wt%Pt. Experiments were performed on a continuous fixed-bed stainless steel reactor at 210-310 °C and pressures up to 15 bar. Three in-house samples were subjected to steaming treatment, and the remaining were acid-leached from a commercial source. The study aimed to evaluate the effect of acid leaching, and its subsequent extraframework alumina (EFAL) species removal, on the performance of bifunctional USY zeolite catalysts during n-heptane transformation. Results have shown that steamed samples generate more cracked products at higher conversions when compared to acid-leached ones, more than likely due to a high presence of EFAL species. The degree of steaming played a role in decreasing cracking tendency at higher pressures, which is attributed to pore structure change and decreasing acidity. In addition, steaming resulted in a catalyst sample capable of generating isomers with blended research octane numbers dose to those achieved with a robust commercial catalyst. However, poisoning experiments have shown that these two catalysts are highly sensitive to sulfur and require sulfur-free feeds in order to demonstrate their full capacities. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24483635

Study of the relationship between framework cation levels of Y zeolites and behavior during calcination, steaming, and n - heptane cracking processes / Bashir Y. Al-Zaidi in Industrial & engineering chemistry research, Vol. 51 N° 19 (Mai 2012) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 51 N° 19 (Mai 2012) . - pp. 6648-6657 Titre : Study of the relationship between framework cation levels of Y zeolites and behavior during calcination, steaming, and n - heptane cracking processes Type de document : texte imprimé Auteurs : Bashir Y. Al-Zaidi, Auteur ; Richard J. Holmes, Auteur ; Arthur A. Garforth, Auteur Année de publication : 2012 Article en page(s) : pp. 6648-6657 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Cracking  Calcining  Zeolite Résumé : The synthesis process and production of forms of the Y zeolite (i.e., NaY, NH4Y, HY, and USY) have been studied in depth, in order to investigate the thermal stability of the Y structure throughout calcination, steaming, and cracking processes. The results indicate that an increase in the cation content within the Y framework during calcination and/or steaming processes led to an increase in the catalyst stability and a reduction in the rate of any associated dehydroxylation reactions. It was also found that the presence of sodium ions hindered the extraction of Al atoms from the crystal lattice structure during the steaming treatment, which minimized partial and/or entire structural collapse at high temperatures. Finally, enhancements in the distribution of the acid sites, and an increase in the activity and selectivity of the produced USY catalysts during n-C7 cracking reactions, have also been observed. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25900218 [article] Study of the relationship between framework cation levels of Y zeolites and behavior during calcination, steaming, and n - heptane cracking processes [texte imprimé] / Bashir Y. Al-Zaidi, Auteur ; Richard J. Holmes, Auteur ; Arthur A. Garforth, Auteur . - 2012 . - pp. 6648-6657. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 19 (Mai 2012) . - pp. 6648-6657 Mots-clés : Cracking  Calcining  Zeolite Résumé : The synthesis process and production of forms of the Y zeolite (i.e., NaY, NH4Y, HY, and USY) have been studied in depth, in order to investigate the thermal stability of the Y structure throughout calcination, steaming, and cracking processes. The results indicate that an increase in the cation content within the Y framework during calcination and/or steaming processes led to an increase in the catalyst stability and a reduction in the rate of any associated dehydroxylation reactions. It was also found that the presence of sodium ions hindered the extraction of Al atoms from the crystal lattice structure during the steaming treatment, which minimized partial and/or entire structural collapse at high temperatures. Finally, enhancements in the distribution of the acid sites, and an increase in the activity and selectivity of the produced USY catalysts during n-C7 cracking reactions, have also been observed. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25900218