Influence of superacid sites in USY zeolites on gasoil cracking
- Univ. Politecnica de Valencia (Spain)
Most petroleum refineries are using high octane cracking catalysts based on ultrastable Y zeolite (USY). Ultrastabilization is achieved by increasing the framework Si/Al ratio of the zeolite by either stream chemical treatments or a combination of both. If a partial dealumination of the Y zeolite is carried out during the manufacture of the catalyst, the ulterior dealumination in the FCC unit becomes slower, and more crystallinity is retained. If partially NH{sub 4}{sup +} exchanged NH{sub 4}NaY zeolite is steam calcined, a slow framework dealumination occurs while silicon migration to stabilize the defects sites takes place. Following this procedure, the extraframework aluminum (EFAL) remains in the zeolite and its exact nature and therefore its catalytic role depends on the method and conditions used for its formation. In a previous paper the authors have shown that by an adequate treatment of steam dealuminated Y zeolites with (NH{sub 4})SiF{sub 6} it is possible to remove the EFAL selectivity. The physicochemical characterization of these samples shows that the presence of EFAL is responsible for the formation of superacid sites, as well as for the neutralization of a part of framework hydroxyls. In this work, they have studied the effect of remotion of the EFAL on the gasoil cracking behavior of the zeolites, as well as the influence of the presence of EFAL on the thermal stability of the samples.
- OSTI ID:
- 7195458
- 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
ALUMINIUM OXIDES
CATALYTIC EFFECTS
GAS OILS
CATALYTIC CRACKING
ZEOLITES
PH VALUE
ALUMINIUM
CATALYSTS
CHEMICAL PREPARATION
DEMETALLIZATION
EXPERIMENTAL DATA
HEPTANE
PETROLEUM
QUANTITY RATIO
REMOVAL
SILICON
STABILIZATION
STEAM
ALKANES
ALUMINIUM COMPOUNDS
CHALCOGENIDES
CHEMICAL REACTIONS
CRACKING
DATA
DECOMPOSITION
DISTILLATES
ELEMENTS
ENERGY SOURCES
FOSSIL FUELS
FUELS
HYDROCARBONS
INFORMATION
INORGANIC ION EXCHANGERS
ION EXCHANGE MATERIALS
MATERIALS
METALS
MINERALS
NUMERICAL DATA
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PETROLEUM DISTILLATES
PETROLEUM FRACTIONS
PETROLEUM PRODUCTS
PYROLYSIS
SEMIMETALS
SEPARATION PROCESSES
SILICATE MINERALS
SYNTHESIS
THERMOCHEMICAL PROCESSES
020300* - Petroleum- Drilling & Production