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Effect of cofeeding butane with methanol on the deactivation by coke of a HZSM-5 zeolite catalyst / Andrés T. Aguayo 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. 9980-9988 Titre : Effect of cofeeding butane with methanol on the deactivation by coke of a HZSM-5 zeolite catalyst Type de document : texte imprimé Auteurs : Andrés T. Aguayo, Auteur ; Pedro Castano, Auteur ; Diana Mier, Auteur Année de publication : 2011 Article en page(s) : pp. 9980-9988 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Catalyst  Zeolite  Deactivation Résumé : The deactivation by coke of a HZSM-5 zeolite catalyst has been studied in the transformation of methanol into hydrocarbons by cofeeding butane (n-butane). This reaction is of interest as an energy-neutral integrated process that enhances the activity in the cracking reaction and upgrades the paraffins formed as byproducts. The process was carried out in a fixed-bed reactor under the following conditions: temperature, 550 °C; pressure, 1 bar; space time, 2.4 and 4.8 (g of catalyst) h (mol of CH2)-1; time on stream, 5 h; methanol/butane molar ratio, up to 16/1. The coke was characterized using several analytical techniques (TG-TPO, FTIR, Raman, and NMR spectroscopies), and the effects of cofeeding butane on the coke composition and structure were determined. The results in terms of coke content and composition, are explained in terms of the different pathways of methanol and butane transformation. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24483641 [article] Effect of cofeeding butane with methanol on the deactivation by coke of a HZSM-5 zeolite catalyst [texte imprimé] / Andrés T. Aguayo, Auteur ; Pedro Castano, Auteur ; Diana Mier, Auteur . - 2011 . - pp. 9980-9988. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 50 N° 17 (Septembre 2011) . - pp. 9980-9988 Mots-clés : Catalyst  Zeolite  Deactivation Résumé : The deactivation by coke of a HZSM-5 zeolite catalyst has been studied in the transformation of methanol into hydrocarbons by cofeeding butane (n-butane). This reaction is of interest as an energy-neutral integrated process that enhances the activity in the cracking reaction and upgrades the paraffins formed as byproducts. The process was carried out in a fixed-bed reactor under the following conditions: temperature, 550 °C; pressure, 1 bar; space time, 2.4 and 4.8 (g of catalyst) h (mol of CH2)-1; time on stream, 5 h; methanol/butane molar ratio, up to 16/1. The coke was characterized using several analytical techniques (TG-TPO, FTIR, Raman, and NMR spectroscopies), and the effects of cofeeding butane on the coke composition and structure were determined. The results in terms of coke content and composition, are explained in terms of the different pathways of methanol and butane transformation. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24483641

Polyethylene cracking on a spent FCC catalyst in a conical spouted bed / Gorka Elordi in Industrial & engineering chemistry research, Vol. 51 N° 43 (Octobre 2012) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 51 N° 43 (Octobre 2012) . - pp. 14008-14017 Titre : Polyethylene cracking on a spent FCC catalyst in a conical spouted bed Type de document : texte imprimé Auteurs : Gorka Elordi, Auteur ; Martin Olazar, Auteur ; Pedro Castano, Auteur Année de publication : 2013 Article en page(s) : pp. 14008-14017 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Fluidization  Spouted  bed  Catalyst  Cracking Résumé : The catalytic cracking of HDPE (high density polyethylene) at 500 °C using a spent FCC catalyst agglomerated with bentonite (50 wt %) has been studied in a conical spouted bed reactor. The reaction is carried out in continuous regime (1 g min―1 of HDPE is fed) with no bed defluidization problems. The results obtained, namely, total conversion, and high yields of gasoline (C5―C11 fraction) (50 wt %) and C2―C4 olefins (28 wt %), are explained by favorable reactor conditions and good catalyst properties. These results are compared with those for a catalyst prepared in the laboratory by agglomerating a commercial HY zeolite (SiO2/Al2O3 = 5.2). The conical spouted bed is a suitable reactor for enhancing the physical steps of melting the polymer and coating the catalyst with the melted polymer. Furthermore, high heat and mass transfer rates promote devolatilization, and short residence times minimize secondary reactions from olefins by enhancing primary cracking products. The meso- and macroporous structure of the spent FCC catalyst matrix enhances the diffusion of long polymer chains, whereas the zeolite crystals have micropores that give a proper shape selectivity to form the lumps of gasoline and light olefins. Because of long use in reaction-regeneration cycles, the moderate acidity of the spent FCC catalyst minimizes the secondary reactions of hydrogen transfer, and so restricts the formation of aromatics and paraffins, as well as the reactions of overcracking and condensation and, therefore, the coke formation. The spent FCC catalyst exhibits a low deactivation rate and is regenerable by coke combustion with air at 550 °C. Consequently, the use of a catalyst with the sole cost of a simple agglomeration and the production of value added product streams make the process of polyolefin catalytic cracking a promising option for refinery integration. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26593328 [article] Polyethylene cracking on a spent FCC catalyst in a conical spouted bed [texte imprimé] / Gorka Elordi, Auteur ; Martin Olazar, Auteur ; Pedro Castano, Auteur . - 2013 . - pp. 14008-14017. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 43 (Octobre 2012) . - pp. 14008-14017 Mots-clés : Fluidization  Spouted  bed  Catalyst  Cracking Résumé : The catalytic cracking of HDPE (high density polyethylene) at 500 °C using a spent FCC catalyst agglomerated with bentonite (50 wt %) has been studied in a conical spouted bed reactor. The reaction is carried out in continuous regime (1 g min―1 of HDPE is fed) with no bed defluidization problems. The results obtained, namely, total conversion, and high yields of gasoline (C5―C11 fraction) (50 wt %) and C2―C4 olefins (28 wt %), are explained by favorable reactor conditions and good catalyst properties. These results are compared with those for a catalyst prepared in the laboratory by agglomerating a commercial HY zeolite (SiO2/Al2O3 = 5.2). The conical spouted bed is a suitable reactor for enhancing the physical steps of melting the polymer and coating the catalyst with the melted polymer. Furthermore, high heat and mass transfer rates promote devolatilization, and short residence times minimize secondary reactions from olefins by enhancing primary cracking products. The meso- and macroporous structure of the spent FCC catalyst matrix enhances the diffusion of long polymer chains, whereas the zeolite crystals have micropores that give a proper shape selectivity to form the lumps of gasoline and light olefins. Because of long use in reaction-regeneration cycles, the moderate acidity of the spent FCC catalyst minimizes the secondary reactions of hydrogen transfer, and so restricts the formation of aromatics and paraffins, as well as the reactions of overcracking and condensation and, therefore, the coke formation. The spent FCC catalyst exhibits a low deactivation rate and is regenerable by coke combustion with air at 550 °C. Consequently, the use of a catalyst with the sole cost of a simple agglomeration and the production of value added product streams make the process of polyolefin catalytic cracking a promising option for refinery integration. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26593328

Transient behavior and stability in miniaturized multiphase packed bed reactors / Nathalie Márquez 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. 1033–1040 Titre : Transient behavior and stability in miniaturized multiphase packed bed reactors Type de document : texte imprimé Auteurs : Nathalie Márquez, Auteur ; Pedro Castano, Auteur ; Jacob A. Moulijn †, Auteur Année de publication : 2010 Article en page(s) : pp. 1033–1040 Note générale : Industrial Chemistry Langues : Anglais (eng) Mots-clés : Transient--Behavior--Stability--Miniaturized--Multiphase--Reactors Résumé : The step response, including various startup procedures, in a three-phase microreactor of 2 mm internal diameter packed with nonporous particles of 100 μm is reported. We demonstrate that the bed behaves reproducibly through many cycles of operating conditions. Interestingly, we find that the different startup procedures have little effect on the steady state that is achieved. In other words, minimal hysteresis was observed, in sharp contrast to larger-scale reactors with larger particles where prewetting has a remarkable impact on the hydrodynamic behavior. The powder-packed beds have very high liquid saturation values, and prewetting is not needed. At least four liquid-residence times were needed to achieve stable pressure drop and dispersion values over the bed. This indicates that the hydrodynamic response into a stable operation may well be the limiting factor that determines the rate at which kinetic experiments can be performed in high-throughput equipment. Note de contenu : Bibiogr. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900694r [article] Transient behavior and stability in miniaturized multiphase packed bed reactors [texte imprimé] / Nathalie Márquez, Auteur ; Pedro Castano, Auteur ; Jacob A. Moulijn †, Auteur . - 2010 . - pp. 1033–1040. Industrial Chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 3 (Fevrier 2010) . - pp. 1033–1040 Mots-clés : Transient--Behavior--Stability--Miniaturized--Multiphase--Reactors Résumé : The step response, including various startup procedures, in a three-phase microreactor of 2 mm internal diameter packed with nonporous particles of 100 μm is reported. We demonstrate that the bed behaves reproducibly through many cycles of operating conditions. Interestingly, we find that the different startup procedures have little effect on the steady state that is achieved. In other words, minimal hysteresis was observed, in sharp contrast to larger-scale reactors with larger particles where prewetting has a remarkable impact on the hydrodynamic behavior. The powder-packed beds have very high liquid saturation values, and prewetting is not needed. At least four liquid-residence times were needed to achieve stable pressure drop and dispersion values over the bed. This indicates that the hydrodynamic response into a stable operation may well be the limiting factor that determines the rate at which kinetic experiments can be performed in high-throughput equipment. Note de contenu : Bibiogr. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900694r