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US 4,392,942 AGranted
Modified staged turbulent bed process for retorting carbon containing solids
AssigneeChevron Research Company
InventorsP. Henrik Wallman, Byron G. Spars
Life of this patent
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Abstract
A process for retorting a carbon containing solid, especially oil shale, comprises passing heat transfer particles and raw particles of carbon containing solid downwardly through a fluidized retort zone containing a plurality of baffles to prevent gross vertical backmixing. The heated solid particles and heat transfer particles are then passed to a moving packed bed retort to pyrolyze the carbon containing solid particles.
Claims13
A continuous process for retorting oil shale which comprises:
- passing heat transfer particles at an elevated temperature and raw shale particles downwardly through a first retort zone;
- passing a first stripping gas upwardly through said first retort zone;
- maintaining the size of the heat transfer particles and the size of the raw shale particles such that a portion of the raw shale particles is fluidized, and a portion of the raw shale particles and at least a portion of the heat transfer particles are nonfluidized in said first retort zone;
- substantially limiting gross vertical backmixing and slugging of the particles within the first retort zone by passing said downwardly moving particles through a plurality of baffles in said first retort zone;
- providing sufficient residence time in the first retort zone for the heavier nonfluidized shale particles to be substantially heated to retorting temperatures;
- passing said heat transfer particles and said heated shale particles from the bottom of said first retort zone to a second, non-fluidized, retort zone;
- maintaining the shale particles in said second retort zone for a residence time sufficient to provide substantially complete pyrolysis of said shale particles;
- passing a second stripping gas through the second retort zone to strip hydrocarbonaceous vapors from the retorted shale;
- withdrawing exhausted first stripping gas from the top of said first retort zone;
- withdrawing exhausted second stripping gas and hydrocarbonaceous vapors from said second retort zone;
- and
- withdrawing heat transfer particles and retorted shale from said second retort zone.
9 more elements
A continuous process for retorting a particulate carbon containing solid which comprises:
- passing heat transfer particles at an elevated temperature and raw carbon containing solid downwardly through a first retort zone;
- passing a first stripping gas upwardly through said first retort zone;
- maintaining the size of the heat transfer particles and the size of the particles of raw carbon containing solid such that a portion of the raw carbon containing solid are fluidized, and a portion of the particles of raw carbon containing solid and at least a portion of the heat transfer particles are nonfluidized in said first retort zone;
- substantially limiting gross vertical backmixing and slugging of the particles within the first retort zone by passing said downwardly moving particles through a plurality of baffles in said first retort zone;
- providing sufficient residence time in the first retort zone for the heavier nonfluidized particles of carbon containing solid to be substantially heated to retorting temperatures;
- passing said heat transfer particles and said heated carbon containing solid particles from the bottom of said first retort zone to a second, non-fluidized, retort zone;
- maintaining the particles of carbon containing solid in said second retort zone for a residence time sufficient to provide substantially complete pyrolysis of said carbon containing solids;
- passing a second stripping gas through the second retort zone to strip hydrocarbonaceous vapors from the retorted solids;
- withdrawing exhausted first stripping gas from the top of said first retort zone;
- withdrawing exhausted second stripping gas and hydrocarbonaceous vapors from said second retort zone;
- and
- withdrawing heat transfer particles and retorted solids from said second retort zone.
9 more elements
Dependencies are inferred from the claim text.