Dehydrogenation - the first step in the cracking of isopentane over silica-alumina cracking catalysts
Earlier work has shown that at low conversions, dehydrogenation is the main primary reaction when isopentane is passed over a silica-alumina catalyst, and that the resulting pentenes largely determine the products and kinetic parameters of cracking. Results reported here indicate that the dehydrogenating activity of the catalyst is intrinsic and not the result of trace impurities. Further, the dehydrogenation activity is not related to the ability of the catalyst to hydrogenate ethylene in a hydrogen-ethylene mixture. The latter activity appears to be the result of catalyst impurities, probably iron, and is easily poisoned by hydrogen sulfide. These observations agree with the conclusion from precious work that at least for isopentane cracking, the traditional ''secondary reaction'' role accorded to the corresponding olefins should be supplanted by considering dehydrogenation of the paraffinic feed as the major primary reaction of cracking, the breaking of the carbon-carbon bond being a subsequent step to dehydrogenation.
- Research Organization:
- The John Hopkins Univ., Baltimore, MD
- OSTI ID:
- 7094371
- Journal Information:
- J. Catal.; (United States), Vol. 75:2
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
2-METHYLBUTANE
CATALYTIC CRACKING
DEHYDROGENATION
ALUMINIUM OXIDES
CATALYTIC EFFECTS
PENTENES
SYNTHESIS
SILICON OXIDES
EXPERIMENTAL DATA
IMPURITIES
IRON
ALKANES
ALKENES
ALUMINIUM COMPOUNDS
CHALCOGENIDES
CHEMICAL REACTIONS
CRACKING
DATA
DECOMPOSITION
ELEMENTS
HYDROCARBONS
INFORMATION
METALS
NUMERICAL DATA
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PYROLYSIS
SILICON COMPOUNDS
THERMOCHEMICAL PROCESSES
TRANSITION ELEMENTS
400301* - Organic Chemistry- Chemical & Physicochemical Properties- (-1987)