Octane enhancement in catalytic cracking using high silica zeolites
- Chevron Research and Technology Co., Richmond, CA (United States)
Approximately 40% of the gasoline produced in the United States is made by fluid catalytic cracking. Because of the need for higher gasoline octane, refiners are looking for economical ways of improving octane in their FCC units, either by changing operating conditions or cracking catalysts. The latter has primarily involved the use of catalysts containing low unit cell size ultrastable-Y zeolite (USY) which produces fewer paraffins and more olefins than conventional rare earth catalysts. A second catalytic option, which may be used in conjunction with USY, is the introduction of a minor amount of a catalyst designed to improve gasoline octane. Anderson et al. and Donnelly et al. have reported on the use of the zeolite ZSM-5 as an additive catalyst for increasing the octane of FCC gasoline. This zeolite has been reported by workers at Mobil to increase octane by cracking out low octane straight chain paraffins and olefins in the heavy gasoline product and by olefin isomerization. Rajagopalan and Young have proposed that the ZSM-5 prevents paraffin formation by cracking out low octane straight chain paraffins and olefins in the heavy gasoline product and by olefin isomerization. Rajagopalan and Young have proposed that the ZSM-5 prevents paraffin formation by cracking carbonium ions or olefin intermediates to light products. In either case, C{sub 3} and C{sub 4} olefins increase while gasoline yield decreases. Chevron researchers have shown that gasoline loss can be reduced by using a ZSM-5-type additive of high silica to alumina ratio, in particular one of SiO{sub 2}/Al{sub 2}O{sub 3} molar ratio greater than 500. FCC additives of the ZSM-5-type are effective for increasing gasoline octane due to their low activity for hydrogen transfer. Octane is increased by the cracking and isomerization of olefins produced by the base cracking catalyst.
- OSTI ID:
- 7152602
- Report Number(s):
- CONF-900802-; CODEN: ACPCA
- Journal Information:
- American Chemical Society, Division of Petroleum Chemistry, Preprints; (United States), Vol. 35:4; Conference: 200. American Chemical Society (ACS) national meeting, Washington, DC (United States), 26-31 Aug 1990; ISSN 0569-3799
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
OCTANE
CHEMICAL REACTION YIELD
PETROLEUM
CATALYTIC CRACKING
ZEOLITES
CATALYTIC EFFECTS
ALKENES
CATALYSTS
CHEMICAL PREPARATION
EXPERIMENTAL DATA
GASOLINE
HYDROGEN TRANSFER
ISOMERIZATION
KNOCK CONTROL
PETROLEUM REFINERIES
PILOT PLANTS
SILICON OXIDES
ALKANES
CHALCOGENIDES
CHEMICAL REACTIONS
CONTROL
CRACKING
DATA
DECOMPOSITION
ENERGY SOURCES
FOSSIL FUELS
FUELS
FUNCTIONAL MODELS
HYDROCARBONS
INDUSTRIAL PLANTS
INFORMATION
INORGANIC ION EXCHANGERS
ION EXCHANGE MATERIALS
LIQUID FUELS
MATERIALS
MINERALS
NUMERICAL DATA
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PETROLEUM PRODUCTS
PYROLYSIS
SILICATE MINERALS
SILICON COMPOUNDS
SYNTHESIS
THERMOCHEMICAL PROCESSES
YIELDS
020400* - Petroleum- Processing