Title data
Ren, Xiaohong ; Bertmer, M. ; Stapf, Siegfried ; Demco, D. E. ; Blümich, Bernhard ; Kern, Christoph ; Jess, Andreas:
Deactivation and regeneration of a naphtha reforming catalyst.
In: Applied Catalysis A: General.
Vol. 228
(2002)
Issue 1-2
.
- pp. 39-52.
ISSN 1873-3875
DOI: https://doi.org/10.1016/S0926-860X(01)00958-9
Abstract in another language
A series of naphtha reforming catalysts from different stages of the deactivation (coking) and the regeneration (decoking) processes were investigated by NMR and chemical engineering methods. The dependence of the tortuosity on the coke content was determined for both processes by NMR measurements of the intraparticle self-diffusion coefficients of adsorbed liquid n-heptane. The shrinkage of the accessible pore volume as a function of increasing coke content due to the deactivation process is compared to nitrogen adsorption (BET) measurements which show an equivalent behavior. A crude model was adapted to predict qualitatively the relationship between the tortuosity and the average pore diameter. Longitudinal (T1) and transverse (T2) NMR relaxation times measured for protons of adsorbed liquid n-heptane, provide information on the pore morphology changes which can be corroborated by the tortuosity measurements. The chemical composition of the coke layer, which was investigated by magic angle spinning (MAS) and cross polarization (CP)/MAS NMR spectroscopy, is shown to change during both deactivation and decoking processes. Moreover, the micro-structure of the fresh catalyst and the fully regenerated catalyst was investigated by scanning electron microscopy (SEM). The experimental results indicate that a full recovery of the activity of the clean catalyst is not achieved by the regeneration process, and that the quality of regeneration depends on the coke content reached during the deactivation/regeneration cycle.
Further data
Item Type: | Article in a journal |
---|---|
Refereed: | Yes |
Keywords: | Coke; Deactivation; Regeneration; NMR; Tortuosity |
Institutions of the University: | Faculties > Faculty of Engineering Science Faculties > Faculty of Engineering Science > Chair Chemical Engineering Faculties > Faculty of Engineering Science > Chair Chemical Engineering > Chair Chemical Engineering - Univ.-Prof. Dr.-Ing. Andreas Jess Faculties |
Result of work at the UBT: | Yes |
DDC Subjects: | 500 Science > 540 Chemistry 600 Technology, medicine, applied sciences > 600 Technology 600 Technology, medicine, applied sciences > 620 Engineering 600 Technology, medicine, applied sciences > 660 Chemical engineering |
Date Deposited: | 06 May 2015 05:37 |
Last Modified: | 28 Aug 2023 06:16 |
URI: | https://eref.uni-bayreuth.de/id/eprint/12698 |