The characterization and elimination of the external acidity of ZSM-5

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dc.contributor.advisorFletcher, Jacken_ZA
dc.contributor.advisorO'Connor, Cyrilen_ZA
dc.contributor.authorWeber, Reinier Willemen_ZA
dc.date.accessioned2016-03-28T14:38:08Z
dc.date.available2016-03-28T14:38:08Z
dc.date.issued1993en_ZA
dc.description.abstractThe 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.en_ZA
dc.identifier.apacitationWeber, R. W. (1993). <i>The characterization and elimination of the external acidity of ZSM-5</i>. (Thesis). University of Cape Town ,Faculty of Engineering & the Built Environment ,Department of Chemical Engineering. Retrieved from http://hdl.handle.net/11427/18301en_ZA
dc.identifier.chicagocitationWeber, Reinier Willem. <i>"The characterization and elimination of the external acidity of ZSM-5."</i> Thesis., University of Cape Town ,Faculty of Engineering & the Built Environment ,Department of Chemical Engineering, 1993. http://hdl.handle.net/11427/18301en_ZA
dc.identifier.citationWeber, R. 1993. The characterization and elimination of the external acidity of ZSM-5. University of Cape Town.en_ZA
dc.identifier.ris TY - Thesis / Dissertation AU - Weber, Reinier Willem AB - 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. DA - 1993 DB - OpenUCT DP - University of Cape Town LK - https://open.uct.ac.za PB - University of Cape Town PY - 1993 T1 - The characterization and elimination of the external acidity of ZSM-5 TI - The characterization and elimination of the external acidity of ZSM-5 UR - http://hdl.handle.net/11427/18301 ER - en_ZA
dc.identifier.urihttp://hdl.handle.net/11427/18301
dc.identifier.vancouvercitationWeber RW. The characterization and elimination of the external acidity of ZSM-5. [Thesis]. University of Cape Town ,Faculty of Engineering & the Built Environment ,Department of Chemical Engineering, 1993 [cited yyyy month dd]. Available from: http://hdl.handle.net/11427/18301en_ZA
dc.language.isoengen_ZA
dc.publisher.departmentDepartment of Chemical Engineeringen_ZA
dc.publisher.facultyFaculty of Engineering and the Built Environment
dc.publisher.institutionUniversity of Cape Town
dc.subject.otherChemical Engineeringen_ZA
dc.titleThe characterization and elimination of the external acidity of ZSM-5en_ZA
dc.typeMaster Thesis
dc.type.qualificationlevelMasters
dc.type.qualificationnameMSc (Eng)en_ZA
uct.type.filetypeText
uct.type.filetypeImage
uct.type.publicationResearchen_ZA
uct.type.resourceThesisen_ZA
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