Multiple riser fluidized catalytic cracking process utilizing hydrogen and carbon-hydrogen contributing fragments
This patent describes a catalytic cracking process. It comprises: cracking a gas oil in a first riser in the presence of a mixed catalyst composition comprising, as a first catalyst component, at least one member of the group of amorphous cracking catalyst and large pore crystalline cracking catalyst and as a second catalyst component, a shape selective zeolite, at a mixed catalyst to feed ratio from about 2:1 to about 20:1 and a temperature from about 900{sup 0} to 1150{sup 0}F to produce cracked products comprising C/sub 1/ to C/sub 5/ hydrocarbons, gasoline boiling range materials and spent catalyst, and stripping at least a portion of spent catalyst to produce stripped catalyst which is regenerated in a catalyst regeneration zone to produce hot, regenerated catalyst; generating in a lower region of a second riser reactor at least one of mobile hydrogen species and carbon-hydrogen fragments by contacting a stream of light hydrocarbons with hot regenerated catalyst at a catalyst to feed ratio of about 50:1 to 200:1 and at a temperature of about 1100{sup 0} to 1500{sup 0}F to form a catalyst-hydrocarbon suspension comprising carbon-hydrogen fragments. The suspension is discharged into an upper region of the second riser; adding a visbroken resid feed to the upper region to contact the catalyst-hydrocarbon suspension discharged from the lower region of the second riser and reacting the visbroken resid in the presence of the mixed catalyst composition under conditions effecting cracking and additive carbon-hydrogen reactions with the resid and forming a resid-catalyst mixture; quenching the resid-catalyst mixture in the second riser by adding thereto a portion of the spent catalyst, discharged from the first riser to produce a quenched resid-catalyst mixture having a temperature of about 950{sup 0} to 1150{sup 0}F and discharging from the second riser a mixture of catalytically cracked products and spent catalyst.
- Assignee:
- Mobil Oil Corp., New York, NY
- Patent Number(s):
- US 4853105
- OSTI ID:
- 5393622
- Resource Relation:
- Patent File Date: 1 Feb 1988
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
GAS OILS
CATALYTIC CRACKING
CATALYSTS
CHEMICAL REACTORS
GASOLINE
HYDROCARBONS
HYDROGEN
PRODUCTION
REGENERATION
CHEMICAL REACTIONS
CRACKING
DECOMPOSITION
ELEMENTS
ENERGY SOURCES
FOSSIL FUELS
FUELS
LIQUID FUELS
NONMETALS
ORGANIC COMPOUNDS
PETROLEUM
PETROLEUM FRACTIONS
PETROLEUM PRODUCTS
PYROLYSIS
THERMOCHEMICAL PROCESSES
020400* - Petroleum- Processing