[article]
Titre : |
HZSM-5 and HY zeolite catalyst performance in the pyrolysis of tires in a conical spouted bed reactor |
Type de document : |
texte imprimé |
Auteurs : |
Miriam Arabiourrutia, Éditeur scientifique ; Martin Olazar, Éditeur scientifique ; Roberto Aguado, Éditeur scientifique |
Année de publication : |
2008 |
Article en page(s) : |
P. 7600-7609 |
Note générale : |
Chemical engineering |
Langues : |
Anglais (eng) |
Mots-clés : |
Zeolite catalyst HZSM-5 zeolite HY |
Résumé : |
A study has been carried out on the in situ use of two catalysts (prepared based on HZSM-5 and HY zeolites) in the pyrolysis of tires in a conical spouted bed reactor at 425 and 500 °C. Both catalysts significantly affect the yields and composition obtained in thermal pyrolysis for the fractions corresponding to C1−C4 gases, nonaromatic C5−C10, aromatic C10−, and tar. The shape selectivity characteristic of each zeolite has a considerable influence on catalyst performance. The HZSM-5 zeolite catalyst produces an increase in the yield of gases, with an increase in the yield of propene and the same yield of butadiene as in thermal pyrolysis, in which it is already high. Concerning the liquid fraction, the catalysts give way to a decrease in the yield of d-limonene (the conical spouted bed reactor performs very well in thermal pyrolysis for this purpose), whereas the yield of BTX aromatics increases, with an increase in the yield of xylenes. A positive fact to be noted is the decrease in the formation of tar (C10+) compared to thermal pyrolysis. As the reaction occurs, a carbonaceous material is deposited on the catalyst, in which the following are identified: (i) carbon black externally coating the particles and deposited on the catalyst macropores and mesopores and (ii) coke deposited on zeolite micropores, due to hydrocarbon condensation activated by catalyst active sites. This condensation preferably takes place in the HY zeolite due to both the larger size of intersections between micropore channels and to greater hydrogen-transfer capacity. Nevertheless, under the reaction conditions tested (up to 10.87 g of tire treated/g of catalyst), product yields remain almost constant, which is evidence that the catalyst does not undergo deactivation. |
En ligne : |
http://pubs.acs.org/doi/abs/10.1021/ie800376d |
in Industrial & engineering chemistry research > Vol. 47 N°20 (Octobre 2008) . - P. 7600-7609
[article] HZSM-5 and HY zeolite catalyst performance in the pyrolysis of tires in a conical spouted bed reactor [texte imprimé] / Miriam Arabiourrutia, Éditeur scientifique ; Martin Olazar, Éditeur scientifique ; Roberto Aguado, Éditeur scientifique . - 2008 . - P. 7600-7609. Chemical engineering Langues : Anglais ( eng) in Industrial & engineering chemistry research > Vol. 47 N°20 (Octobre 2008) . - P. 7600-7609
Mots-clés : |
Zeolite catalyst HZSM-5 zeolite HY |
Résumé : |
A study has been carried out on the in situ use of two catalysts (prepared based on HZSM-5 and HY zeolites) in the pyrolysis of tires in a conical spouted bed reactor at 425 and 500 °C. Both catalysts significantly affect the yields and composition obtained in thermal pyrolysis for the fractions corresponding to C1−C4 gases, nonaromatic C5−C10, aromatic C10−, and tar. The shape selectivity characteristic of each zeolite has a considerable influence on catalyst performance. The HZSM-5 zeolite catalyst produces an increase in the yield of gases, with an increase in the yield of propene and the same yield of butadiene as in thermal pyrolysis, in which it is already high. Concerning the liquid fraction, the catalysts give way to a decrease in the yield of d-limonene (the conical spouted bed reactor performs very well in thermal pyrolysis for this purpose), whereas the yield of BTX aromatics increases, with an increase in the yield of xylenes. A positive fact to be noted is the decrease in the formation of tar (C10+) compared to thermal pyrolysis. As the reaction occurs, a carbonaceous material is deposited on the catalyst, in which the following are identified: (i) carbon black externally coating the particles and deposited on the catalyst macropores and mesopores and (ii) coke deposited on zeolite micropores, due to hydrocarbon condensation activated by catalyst active sites. This condensation preferably takes place in the HY zeolite due to both the larger size of intersections between micropore channels and to greater hydrogen-transfer capacity. Nevertheless, under the reaction conditions tested (up to 10.87 g of tire treated/g of catalyst), product yields remain almost constant, which is evidence that the catalyst does not undergo deactivation. |
En ligne : |
http://pubs.acs.org/doi/abs/10.1021/ie800376d |
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