US 5,277,880 AGranted

Catalyst regeneration apparatus with radial flow distribution

AssigneeUop LLC

InventorsPaul A. Sechrist, William J. Koves

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Abstract

Apparatus for regenerating spent hydrocarbon conversion catalyst. Catalyst particles in a vertically-elongated movable tapered bed are contacted with a hot oxygen-containing gas stream in order to remove, by means of combustion, coke which accumulated on the catalyst particles while they were used in a hydrocarbon conversion zone. Catalyst moves downward under the influence of gravity. The catalyst bed is tapered such that the thickness of the bed, in a dimension which is transverse to the direction of catalyst movement, varies from a minimum at the top of the tapered bed to a maximum at the bottom of the tapered bed. Gas passes through the tapered bed in a direction which is substantially transverse to the direction of catalyst movement. Substantially, all of the catalyst in the bed is in contact with the flowing gas. The variation in bed thickness causes a varying gas flow rate through the bed, from a maximum flow rate at the top of the tapered bed to a minimum flow rate at the bottom of the tapered bed and reduces the time that catalyst is exposed to high temperature gases. This flow pattern results in the delivery of oxygen in a manner which more closely matches the oxygen requirement for combustion at each point in the tapered bed. Advantages of the invention include increased coke burning capacity and longer catalyst life. Catalytic reforming is an example of a hydrocarbon conversion process in which the invention may be advantageously employed.

Apparatus for at least partially regenerating spent catalyst particles used in hydrocarbon conversion reactions by the combustion of coke which is comprised of:

(a) a vertically-elongated vessel;
(b) a hollow-form screen assembly located in said vessel having vertically extended inner and outer sections, at least one of said sections being tapered in a vertical direction to downwardly progressively increase the horizontal distance between the inner and outer screens and provide a tapered screen section having an overall taper angle of from 1 to less than 6.degree., that permit gas flow and confinement of catalyst particles, said screen sections extending vertically within said vessel and together forming a vertically elongated catalyst bed section therebetween for the combustion of coke, said bed section having an open bottom to permit an at least semi-continuous downward gravity flow of catalyst particles, said tapered screen section providing a horizontal distance between surfaces of adjacent screen sections that includes a distance of no more than 5 inches at the top of said catalyst bed section and each of said screen sections having openings;
(c) means for adding catalyst particles to the top of said catalyst bed section;
(d) means for withdrawing catalyst particles from the bottom of said catalyst bed section;
(e) at least one of said screens defining a recycle gas distribution space extending without restriction from the top to the bottom of said catalyst bed section for distributing recycle gas about one of said outer screen section of said inner screen section and a flue gas collection space extending from the top to the bottom of said catalyst bed section arranged for collecting flue gas from about the other of said inner screen section or said outer screen section, said distribution and collection spaces being arranged such that gas will flow in a substantially horizontal direction through said catalyst bed section;
(f) means for supplying recycle gas to said distribution space;
and
(g) means for withdrawing flue gas from said collection space.

5 more elements

Facts

Application

07/826,498Filed 27 Jan 1992 · continuation in part

Priority

11 May 1988

Granted

11 Jan 1994

Term ends

Not estimatedThe source records don’t support an estimate.

Classification6 codes

B01J 38/40
Treating with free oxygen-containing gas: and forming useful by-products
B01J 8/12
With moving particles: moved by gravity in a downward flow
B01J 38/32
In gaseous suspension, e.g. fluidised bed: indirectly heating or cooling material within regeneration zone or prior to entry into regeneration zone
C10G 45/12
Characterised by the catalyst used: containing crystalline alumino-silicates, e.g. molecular sieves

Abstract

Claims7