A time- and space-resolved catalyst deactivation study on the conversion of glycerol to aromatics using H-ZSM-5

Autor: Songbo He, Hero Reinder Goldhoorn, Zhuorigebatu Tegudeer, Anshu Chandel, Andre Heeres, Marc C.A. Stuart, Hero Jan Heeres
Přispěvatelé: Chemical Technology, Electron Microscopy, Biobased Chemistry and Refinery
Jazyk: angličtina
Rok vydání: 2022
Předmět:
Zdroj: Chemical Engineering Journal, 434:134620. Elsevier Science
Chemical Engineering Journal, 434:134620. Elsevier
ISSN: 1385-8947
Popis: A time- and space-resolved deactivation study on the conversion of glycerol to aromatics over H-ZSM-5 was performed. For this purpose, glycerol was vaporized/pyrolyzed in a pyrolysis section followed by a catalytic aromatization step. Benchmark performance showed an induction period of ca. 20 min, followed by a rather constant BTX yield of ca. 25.4 ± 2.2C.% for 3–4 h time on stream (TOS). Subsequently, a rapid drop in BTX yield was observed due to catalyst deactivation. Severe coking leads to coverage of catalyst surface area and blockage of micropores, particularly at the entrance of the catalyst bed at short TOS, indicating the presence of an axial coke gradient in the fixed bed reactor. At longer TOS, coke was formed throughout the bed and negligible BTX yield was shown to be associated with the presence of coke at all bed positions. Besides coking, the acidity of the catalyst was also reduced, and dealumination occurred, both with a similar time–space evolution. The results were explained by a conversion-zone migration model, which includes a deactivation zone (with severely coked catalyst), a conversion zone (BTX formation), and an induction zone (a.o. (de-)alkylation reactions), and describes the time- and space-resolved evolution of coking and relevant changes in other catalyst characteristics.
Databáze: OpenAIRE
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