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Solid particle erosion of ceramics
The zeolite ZSM-5 is well-known for its unique intersecting channel system. This channel system has a great bearing on the shape-selective properties and the long life-times of ZSM-5. In this study, ZSM-5 was modified in various ways to eliminate the external acidity of the catalyst to further impro...
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| Format: | Thesis |
| Language: | English |
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Centre for Materials Engineering
2016
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| _version_ | 1867614218478419968 |
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| access_status_str | Open Access |
| author | Wellman, R G |
| author2 | Allen, Colin |
| author_browse | Allen, Colin Wellman, R G |
| author_facet | Allen, Colin Wellman, R G |
| author_sort | Wellman, R G |
| collection | Thesis |
| description | The zeolite ZSM-5 is well-known for its unique intersecting channel system. This channel system has a great bearing on the shape-selective properties and the long life-times of ZSM-5. In this study, ZSM-5 was modified in various ways to eliminate the external acidity of the catalyst to further improve these properties, and the success and effects of these modifications were investigated primarily using temperature programmed desorption techniques. The internal surface of ZSM-5, a medium pore zeolite, plays a major role in the shape selective properties of this catalyst, due to the diffusional restrictions imposed by the channel system on bulky molecules. Even though the number of acid sites on the external surface is small compared to the total number of acid sites, these easily accessible and non-shape selective acid sites may provide a high turnover rate for non-shape selective reactions. Furthermore, the main cause of deactivation of ZSM-5 is thought to be the formation of polyaromatic molecules on the external surface, which block access to the channels of the catalyst. |
| format | Thesis |
| id | oai:open.uct.ac.za:11427/18219 |
| institution | University of Cape Town (South Africa) |
| language | eng |
| last_indexed | 2026-06-10T12:48:33.118Z |
| license_str | Not specified — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from UCTD — University of Cape Town Open Access Repository |
| publishDate | 2016 |
| publishDateRange | 2016 |
| publishDateSort | 2016 |
| publisher | Centre for Materials Engineering |
| publisherStr | Centre for Materials Engineering |
| record_format | dspace |
| source_str | UCTD — University of Cape Town Open Access Repository |
| spelling | oai:open.uct.ac.za:11427/18219 Solid particle erosion of ceramics Wellman, R G Allen, Colin Materials Engineering Applied Science The zeolite ZSM-5 is well-known for its unique intersecting channel system. This channel system has a great bearing on the shape-selective properties and the long life-times of ZSM-5. In this study, ZSM-5 was modified in various ways to eliminate the external acidity of the catalyst to further improve these properties, and the success and effects of these modifications were investigated primarily using temperature programmed desorption techniques. The internal surface of ZSM-5, a medium pore zeolite, plays a major role in the shape selective properties of this catalyst, due to the diffusional restrictions imposed by the channel system on bulky molecules. Even though the number of acid sites on the external surface is small compared to the total number of acid sites, these easily accessible and non-shape selective acid sites may provide a high turnover rate for non-shape selective reactions. Furthermore, the main cause of deactivation of ZSM-5 is thought to be the formation of polyaromatic molecules on the external surface, which block access to the channels of the catalyst. 2016-03-28T14:21:31Z 2016-03-28T14:21:31Z 1993 Master Thesis Masters MSc http://hdl.handle.net/11427/18219 eng application/pdf Centre for Materials Engineering Faculty of Engineering and the Built Environment University of Cape Town |
| spellingShingle | Materials Engineering Applied Science Wellman, R G Solid particle erosion of ceramics |
| thesis_degree_str | Master's |
| title | Solid particle erosion of ceramics |
| title_full | Solid particle erosion of ceramics |
| title_fullStr | Solid particle erosion of ceramics |
| title_full_unstemmed | Solid particle erosion of ceramics |
| title_short | Solid particle erosion of ceramics |
| title_sort | solid particle erosion of ceramics |
| topic | Materials Engineering Applied Science |
| url | http://hdl.handle.net/11427/18219 |
| work_keys_str_mv | AT wellmanrg solidparticleerosionofceramics |