{"id":{"repo_id":"wvu","oai_identifier":"oai:researchrepository.wvu.edu:etd-1935"},"canonical_url":"https://search.dev.ndltd.org/etd/wvu/oai:researchrepository.wvu.edu:etd-1935","repository":{"repo_id":"wvu","name":"West Virginia University","base_url":"https://researchrepository.wvu.edu/do/oai/"},"display":{"title":"Hydrothermal aging of zeolite-based catalysts","abstract":"In this study the RE-USY (Davision GO-40) FCC catalyst, a composite of RE-USY zeolite and alumina-silica gel matrix, was treated hydrothermally under simulated FCC regenerator conditions in a laboratory scale fluidized bed. Fresh and steam-aged catalysts were characterized by surface area reduction using the nitrogen BET and t-Plot surface area methods. The surface morphology was apparent from the scanning electron photomicrographs. An irreversible deactivation kinetic model developed earlier by Gardner.; S0- S/S0 ns=Ks t was applied to account for changes of surface area of the zeolite component as a function of time on stream, temperature and steam partial pressure. The kinetic parameters, Ks, the apparent global zeolite hydrothermal stability rate constant and ns, a constant which was determined to be a function of steam partial pressure for a given temperature were determined and compared to those of H-USY (Davision Octacat) FCC catalyst.;An effect of rare-earth exchange on deactivation kinetics was observed. The RE-USY was found to exhibit greater hydrothermal stability than the H-USY determined by the smaller hydrothermal stability rate constant, Ks, and the smaller ns. The presence of rare-earth ions in the zeolite was suggested to prevent extraction of aluminum atoms which caused the hydrothermal destruction of zeolite framework.","abstract_html":"In this study the RE-USY (Davision GO-40) FCC catalyst, a composite of RE-USY zeolite and alumina-silica gel matrix, was treated hydrothermally under simulated FCC regenerator conditions in a laboratory scale fluidized bed. Fresh and steam-aged catalysts were characterized by surface area reduction using the nitrogen BET and t-Plot surface area methods. The surface morphology was apparent from the scanning electron photomicrographs. An irreversible deactivation kinetic model developed earlier by Gardner.; S0- S/S0 ns=Ks t was applied to account for changes of surface area of the zeolite component as a function of time on stream, temperature and steam partial pressure. The kinetic parameters, Ks, the apparent global zeolite hydrothermal stability rate constant and ns, a constant which was determined to be a function of steam partial pressure for a given temperature were determined and compared to those of H-USY (Davision Octacat) FCC catalyst.;An effect of rare-earth exchange on deactivation kinetics was observed. The RE-USY was found to exhibit greater hydrothermal stability than the H-USY determined by the smaller hydrothermal stability rate constant, Ks, and the smaller ns. The presence of rare-earth ions in the zeolite was suggested to prevent extraction of aluminum atoms which caused the hydrothermal destruction of zeolite framework.","abstract_has_math":false,"creators":["Panpranot, Joongjai"],"institution":null,"degree_name":"MS","degree_level":"Thesis","degree_discipline":"Chemical and Biomedical Engineering","degree_department":null,"school":null,"contributors":["Edwin L. Kugler."],"advisors":[],"committee_chairs":[],"committee_members":[],"year":1998,"date_issued":"1998-12-01T08:00:00Z","date_published":"1998-12-01T08:00:00Z","updated_at":"2026-07-24T06:15:08Z","subjects":["Chemical engineering"],"languages":[],"rights":[],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["https://researchrepository.wvu.edu/etd/932"],"render_values":[{"text":"https://researchrepository.wvu.edu/etd/932","href":"https://researchrepository.wvu.edu/etd/932","code":true}]}]},"links":{"outbound_url":"https://doi.org/10.33915/etd.932","outbound_label":"DOI","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Edwin L. 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Fresh and steam-aged catalysts were characterized by surface area reduction using the nitrogen BET and t-Plot surface area methods. The surface morphology was apparent from the scanning electron photomicrographs. An irreversible deactivation kinetic model developed earlier by Gardner.; S0- S/S0 ns=Ks t was applied to account for changes of surface area of the zeolite component as a function of time on stream, temperature and steam partial pressure. The kinetic parameters, Ks, the apparent global zeolite hydrothermal stability rate constant and ns, a constant which was determined to be a function of steam partial pressure for a given temperature were determined and compared to those of H-USY (Davision Octacat) FCC catalyst.;An effect of rare-earth exchange on deactivation kinetics was observed. The RE-USY was found to exhibit greater hydrothermal stability than the H-USY determined by the smaller hydrothermal stability rate constant, Ks, and the smaller ns. The presence of rare-earth ions in the zeolite was suggested to prevent extraction of aluminum atoms which caused the hydrothermal destruction of zeolite framework."]},{"key":"dc:title","label":"Title","values":["Hydrothermal aging of zeolite-based catalysts"]}]}],"canonical_facts":{"dc:contributor":["Edwin L. Kugler."],"dc:creator":["Panpranot, Joongjai"],"dc:date.available":["2019-01-17T08:00:00Z"],"dc:description.abstract":["In this study the RE-USY (Davision GO-40) FCC catalyst, a composite of RE-USY zeolite and alumina-silica gel matrix, was treated hydrothermally under simulated FCC regenerator conditions in a laboratory scale fluidized bed. Fresh and steam-aged catalysts were characterized by surface area reduction using the nitrogen BET and t-Plot surface area methods. The surface morphology was apparent from the scanning electron photomicrographs. An irreversible deactivation kinetic model developed earlier by Gardner.; S0- S/S0 ns=Ks t was applied to account for changes of surface area of the zeolite component as a function of time on stream, temperature and steam partial pressure. The kinetic parameters, Ks, the apparent global zeolite hydrothermal stability rate constant and ns, a constant which was determined to be a function of steam partial pressure for a given temperature were determined and compared to those of H-USY (Davision Octacat) FCC catalyst.;An effect of rare-earth exchange on deactivation kinetics was observed. The RE-USY was found to exhibit greater hydrothermal stability than the H-USY determined by the smaller hydrothermal stability rate constant, Ks, and the smaller ns. The presence of rare-earth ions in the zeolite was suggested to prevent extraction of aluminum atoms which caused the hydrothermal destruction of zeolite framework."],"dc:identifier":["https://doi.org/10.33915/etd.932","https://researchrepository.wvu.edu/etd/932"],"dc:subject":["Chemical engineering"],"dc:title":["Hydrothermal aging of zeolite-based catalysts"],"thesis:degree_discipline":["Chemical and Biomedical Engineering"],"thesis:degree_level":["Thesis"],"thesis:degree_name":["MS"]},"updated_at":"2026-07-24T06:15:08Z"}