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Parametric characterization and influence of tin on the performance of Pt−Sn/SAPO-34 catalyst for selective propane dehydrogenation to propylene / Zeeshan Nawaz 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. 1274–1280 Titre : Parametric characterization and influence of tin on the performance of Pt−Sn/SAPO-34 catalyst for selective propane dehydrogenation to propylene Type de document : texte imprimé Auteurs : Zeeshan Nawaz, Auteur ; Xiaoping Tang, Auteur ; Yao Wang, Auteur Année de publication : 2010 Article en page(s) : pp. 1274–1280 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Parametric--Characterization--Influence--Tin  on  the  Performance--Pt−Sn/SAPO-34--Catalyst--Selective  Propane--Dehydrogenation--Propylene Résumé : The selective propane dehydrogenation to propylene was studied to enhance Pt−Sn/SAPO-34 catalyst performance. The objective was to achieve higher propylene selectivity; therefore, the reaction was parametrically characterized to obtain necessary information to integrate the process operating conditions. The optimum operating conditions were found to be temperature 585 °C, weight hour space velocity 5.6 h−1 or lower, H2/C3H8 molar ratio 0.25, and conversion range 14−25%. Further intensification and the role of Sn on the performance of Pt−Sn/SAPO-34 catalyst were investigated, as stereochemistry and thermodynamics are inextricably tied up with each other. The catalyst was characterized by a number of physiochemical techniques: X-ray fluorescence, Brunauer−Emmett−Teller surface area measurement, X-ray diffraction, temperature-programmed desorption of NH3, temperature-programmed reduction of H2, infrared spectra, temperature-programmed oxidation, and O2-pulse coke analysis. The catalytic performance was largely improved with the presence of Sn up to a certain limit; after that, it caused diminution in the reaction rate. The Sn loading modifies surface Pt ensembles; those helped Pt to be well dispersed by changing the interfacial character between the metal and support. Moreover, Sn facilitates the transfer of carbon deposit from the metal sites to the support. In general, it is noted that the increase in Sn content from 1 wt % affects catalyst performance adversely. Higher propylene selectivity (94%) and total olefin selectivity (97.2%) were obtained using [Pt(0.5 wt %) − Sn(1 wt %)]/SAPO-34. ISSN : 0888-5885 [article] Parametric characterization and influence of tin on the performance of Pt−Sn/SAPO-34 catalyst for selective propane dehydrogenation to propylene [texte imprimé] / Zeeshan Nawaz, Auteur ; Xiaoping Tang, Auteur ; Yao Wang, Auteur . - 2010 . - pp. 1274–1280. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 3 (Fevrier 2010) . - pp. 1274–1280 Mots-clés : Parametric--Characterization--Influence--Tin  on  the  Performance--Pt−Sn/SAPO-34--Catalyst--Selective  Propane--Dehydrogenation--Propylene Résumé : The selective propane dehydrogenation to propylene was studied to enhance Pt−Sn/SAPO-34 catalyst performance. The objective was to achieve higher propylene selectivity; therefore, the reaction was parametrically characterized to obtain necessary information to integrate the process operating conditions. The optimum operating conditions were found to be temperature 585 °C, weight hour space velocity 5.6 h−1 or lower, H2/C3H8 molar ratio 0.25, and conversion range 14−25%. Further intensification and the role of Sn on the performance of Pt−Sn/SAPO-34 catalyst were investigated, as stereochemistry and thermodynamics are inextricably tied up with each other. The catalyst was characterized by a number of physiochemical techniques: X-ray fluorescence, Brunauer−Emmett−Teller surface area measurement, X-ray diffraction, temperature-programmed desorption of NH3, temperature-programmed reduction of H2, infrared spectra, temperature-programmed oxidation, and O2-pulse coke analysis. The catalytic performance was largely improved with the presence of Sn up to a certain limit; after that, it caused diminution in the reaction rate. The Sn loading modifies surface Pt ensembles; those helped Pt to be well dispersed by changing the interfacial character between the metal and support. Moreover, Sn facilitates the transfer of carbon deposit from the metal sites to the support. In general, it is noted that the increase in Sn content from 1 wt % affects catalyst performance adversely. Higher propylene selectivity (94%) and total olefin selectivity (97.2%) were obtained using [Pt(0.5 wt %) − Sn(1 wt %)]/SAPO-34. ISSN : 0888-5885

Pt−sn-based SAPO-34 supported novel catalyst for n-butane dehydrogenation / Zeeshan Nawaz in Industrial & engineering chemistry research, Vol. 48 N° 15 (Août 2009) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 48 N° 15 (Août 2009) . - pp. 7442–7447 Titre : Pt−sn-based SAPO-34 supported novel catalyst for n-butane dehydrogenation Type de document : texte imprimé Auteurs : Zeeshan Nawaz, Auteur ; Wei Fei, Auteur Année de publication : 2009 Article en page(s) : pp. 7442–7447 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : Pt−Sn/SAPO-34  novel  catalyst  n-butane  dehydrogenation  X-ray  fluorescence  X-ray  diffraction Résumé : The performance of Pt−Sn/SAPO-34 novel catalyst was investigated for n-butane dehydrogenation. The catalyst was characterized by number of physiochemical techniques X-ray fluorescence (XRF), X-ray diffraction (XRD), ammonia temperature-programmed desorption (NH3-TPD), hydrogen temperature-programmed reduction (H2-TPR), temperature-programmed oxidation (TPO), transmission electron microscopy (TEM), and O2-pulse coke measurement. The metallic contents, structure, acidity, and metallic dispersion were determined in order to explain catalyst superiority and functionality using SAPO-34 as support. Pt−Sn-based SAPO-34 supported catalyst was parametrically characterized in order to obtain superior control of dehydrogenation reaction stereochemistry. Above 91% of total olefins with 80% butene was achieved over Pt−Sn/SAPO-34. The weight hourly space velocity 2.8 h−1 and temperature 585 °C were found to be optimum for the higher dehydrogenation activity. The catalysts also showed very good hydrothermal stability in continuous reaction−regeneration cycles. The coke formation was mainly related to catalyst activity. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900801m [article] Pt−sn-based SAPO-34 supported novel catalyst for n-butane dehydrogenation [texte imprimé] / Zeeshan Nawaz, Auteur ; Wei Fei, Auteur . - 2009 . - pp. 7442–7447. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 15 (Août 2009) . - pp. 7442–7447 Mots-clés : Pt−Sn/SAPO-34  novel  catalyst  n-butane  dehydrogenation  X-ray  fluorescence  X-ray  diffraction Résumé : The performance of Pt−Sn/SAPO-34 novel catalyst was investigated for n-butane dehydrogenation. The catalyst was characterized by number of physiochemical techniques X-ray fluorescence (XRF), X-ray diffraction (XRD), ammonia temperature-programmed desorption (NH3-TPD), hydrogen temperature-programmed reduction (H2-TPR), temperature-programmed oxidation (TPO), transmission electron microscopy (TEM), and O2-pulse coke measurement. The metallic contents, structure, acidity, and metallic dispersion were determined in order to explain catalyst superiority and functionality using SAPO-34 as support. Pt−Sn-based SAPO-34 supported catalyst was parametrically characterized in order to obtain superior control of dehydrogenation reaction stereochemistry. Above 91% of total olefins with 80% butene was achieved over Pt−Sn/SAPO-34. The weight hourly space velocity 2.8 h−1 and temperature 585 °C were found to be optimum for the higher dehydrogenation activity. The catalysts also showed very good hydrothermal stability in continuous reaction−regeneration cycles. The coke formation was mainly related to catalyst activity. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900801m

Study of propane dehydrogenation to propylene in an integrated fluidized bed reactor using Pt - Sn /Al - SAPO - 34 novel catalyst / Zeeshan Nawaz in Industrial & engineering chemistry research, Vol. 49 N° 10 (Mai 2010) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4614–4619 Titre : Study of propane dehydrogenation to propylene in an integrated fluidized bed reactor using Pt - Sn /Al - SAPO - 34 novel catalyst Type de document : texte imprimé Auteurs : Zeeshan Nawaz, Auteur ; Yue Chu, Auteur ; Wei, Yang, Auteur Année de publication : 2010 Article en page(s) : pp. 4614–4619 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Catalyst Résumé : Direct propane dehydrogenation is the most economical route to propylene, but very complex due to endothermic reaction requirements, equilibrium limitations, stereochemistry, and engineering constraints. The state of the art idea of bimodal particle (gas−solid−solid) fluidization was applied, in order to overcome alkane dehydrogenation reaction barriers in a fluidized bed technology. In this study, the propane dehydrogenation reaction was studied in an integrated fluidized bed reactor, using Pt-Sn/Al-SAPO-34 novel catalyst at 590 °C. The results of fixed bed microreactor and integrated bimodal particle fluidized bed reactors were compared and parametrically characterized. The results showed that the propylene selectivity is over 95%, with conversion between 31 and 24%. This significant enhancement is by using novel bimodal particle fluidization system, owing to uniform heat transfer throughout the reactor and transfer coke from principal catalyst to secondary catalyst, which increases principal catalyst’s stability. Experimental investigation reveals that the novel Pt-Sn/Al-SAPO-34 catalyst and proposed intensified design of fluidized bed reactor is a promising opportunity for direct propane dehydrogenation to propylene, with both economic and operational benefit. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie902043w [article] Study of propane dehydrogenation to propylene in an integrated fluidized bed reactor using Pt - Sn /Al - SAPO - 34 novel catalyst [texte imprimé] / Zeeshan Nawaz, Auteur ; Yue Chu, Auteur ; Wei, Yang, Auteur . - 2010 . - pp. 4614–4619. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4614–4619 Mots-clés : Catalyst Résumé : Direct propane dehydrogenation is the most economical route to propylene, but very complex due to endothermic reaction requirements, equilibrium limitations, stereochemistry, and engineering constraints. The state of the art idea of bimodal particle (gas−solid−solid) fluidization was applied, in order to overcome alkane dehydrogenation reaction barriers in a fluidized bed technology. In this study, the propane dehydrogenation reaction was studied in an integrated fluidized bed reactor, using Pt-Sn/Al-SAPO-34 novel catalyst at 590 °C. The results of fixed bed microreactor and integrated bimodal particle fluidized bed reactors were compared and parametrically characterized. The results showed that the propylene selectivity is over 95%, with conversion between 31 and 24%. This significant enhancement is by using novel bimodal particle fluidization system, owing to uniform heat transfer throughout the reactor and transfer coke from principal catalyst to secondary catalyst, which increases principal catalyst’s stability. Experimental investigation reveals that the novel Pt-Sn/Al-SAPO-34 catalyst and proposed intensified design of fluidized bed reactor is a promising opportunity for direct propane dehydrogenation to propylene, with both economic and operational benefit. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie902043w