Ethylbenzene disproportionation and p -xylene selectivity enhancement in xylene isomerization using high crystallinity desilicated H-ZSM-5
| Autor: | Cavus Falamaki, Marjan Farshadi |
|---|---|
| Rok vydání: | 2018 |
| Předmět: |
Environmental Engineering
General Chemical Engineering Inorganic chemistry Xylene Disproportionation 02 engineering and technology General Chemistry 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences Biochemistry Ethylbenzene p-Xylene 0104 chemical sciences chemistry.chemical_compound Crystallinity chemistry ZSM-5 0210 nano-technology Zeolite Isomerization |
| Zdroj: | Chinese Journal of Chemical Engineering. 26:116-126 |
| ISSN: | 1004-9541 |
| Popis: | Desilication accompanied with minimum loss of crystallinity effect of a high alumina ZSM-5 zeolite on the isomerization reaction of ethylbenzene/xylene mixtures has been considered. Desilication was assessed through XRF, XRD, FTIR, TEM, nitrogen adsorption/desorption, NH 3 -TPD, 29 Si and 27 Al MAS NMR analytical techniques. Desilication was accompanied with the creation of super acid sites. There exists a limit (Si/Al molar ratio of 9.67) for keeping high crystallinity and obtaining improved catalytic performance. Desilication promotes ethylbenzene conversion by disproportionation and trans-alkylation reactions while the same reactions are limited for the xylene isomers. The p -xylene approach to equilibrium improves by more than 7% at 400 °C and a WHSV of 2 h − 1 for the optimum sample with respect to the parent zeolite. At the same conditions, the optimum sample exhibits the maximum ethylbenzene conversion of 89%, i.e. more than 40% w.r.t. of the parent zeolite. However, the xylene yield decreases only 3%. |
| Databáze: | OpenAIRE |
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