US 4,064,018 AGranted

Internally circulating fast fluidized bed flash pyrolysis reactor

AssigneeOccidental Petroleum Corporation

InventorCharles K. Choi

Life of this patent

Estimating the term…

Abstract

Solid carbonaceous materials are pyrolyzed by feeding the carbonaceous material along with a particulate source of heat to a fast fluidized bed contained within a vertically disposed duct. An internally circulating stream of spent particulate source of heat and carbon containing solid residue of the pyrolysis of the carbonaceous material flows upwardly along the inner surface of the duct, thereby preventing carbonaceous material from caking on the duct.

Claims34

Dependent claims

In a process for the pyrolysis of solid carbonaceous materials in which the carbonaceous material is pyrolyzed by heat transferred thereto from a high temperature, particulate solid source of heat to yield as products of pyrolysis a pyrolytic vapor containing hydrocarbons and a particulate carbon containing solid residue, an improved method of achieving pyrolysis comprising the steps of:

a. simultaneously introducing upwardly to the base of an upwardly flowing fast fluidized bed contained within a substantially vertically disposed open duct, said open duct at least partially surrounded by a descending dense fluidized mass of particulate solids including particulate carbon containing solid residue of pyrolysis and spent particulate source of heat, a particulate carbonaceous material contained in a carrier gas which is nondeleteriously reactive with respect to the products of pyrolysis and a particulate source of heat to contact and pyrolyze the carbonaceous material, the introduced quantity of particulate solid source of heat being sufficient to raise the carbonaceous material to a pyrolysis temperature of at least about 600.degree. F to yield as products of pyrolysis pyrolytic vapor and particulate carbon containing solid residue, while simultaneously maintaining a flow of solids from the surrounding dense fluidized mass upwardly along the inner surface of the duct to prevent contact of the carbonaceous material with the inner surface of the duct;
b. discharging (i) at least a portion of the spent particulate source of heat and particulate carbon containing solid residue resulting from pyrolysis over the top end of the open duct to the descending dense fluidized mass of particulate solids and (ii) a stream comprising a gaseous mixture of carrier gas, pyrolytic vapor and entrained particulate solids including spent particulate solid source of heat and carbon containing solid residue from the upper portion of the duct and through an outlet above the fluidized bed;
c. separating the entrained solids from the gaseous mixture in a separation zone;
and
d. recovering hydrocarbon values from the gaseous mixture.

2 more elements

A process for pyrolysis of carbonaceous materials comprising the steps of:

a. simultaneously introducing through first and second solids inlets which are coaxial only at their terminal portions to the base of an upwardly flowing fast fluidized bed contained within a substantially vertically disposed, open, cylindrical dust surrounded by a descending dense fluidized mass of particulate solids including particulate carbon containing solid residue and spent particulate source of heat maintained fluidized by an ascending stream of a stripping gas which is nondeleteriously reactive with respect to pyrolysis products, a particulate carbonaceous material contained in a carrier gas which is nondeleteriously reactive with respect to the products of pyrolysis and a particulate source of heat to contact and initiate pyrolysis of the carbonaceous material to yield in a pyrolysis time of from about 0.1 to about 5 seconds as products of pyrolysis pyrolytic vapor and particulate carbon containing solid residue, the weight ratio of the particulate source of heat to carbonaceous material being from about 2 to about 20:1 and the temperature of the particulate source of heat being sufficient to raise carbonaceous material to a pyrolysis temperature of from about 600.degree. to about 1400.degree. F, while simultaneously maintaining a flow of solids from the surrounding dense fluidized mass upwardly along the inner surface of the duct to prevent contact of the carbonaceous material with the inner surface of the duct by discharging into the base of the duct upwardly along the inner surface of said duct a fluidizing gas which is nondeleteriously reactive with respect to pyrolysis products;
b. discharging (i) a portion of the particulate source of heat and particulate carbon containing solid residue resulting from pyrolysis over the top edge of the duct to the descending dense fluidized mass of particulate solids and (ii) a stream comprising a gaseous mixture of carrier gas, pyrolytic vapors, and entrained particulate solids including spent particulate solid source of heat and carbon containing solid residue from the top portion of the duct and through an outlet above the fluidized bed and separating the entrained solids from the gaseous mixture in a cyclone separation zone;
c. recovering hydrocarbons from the gaseous mixture;
and
d. cycling the separated entrained solids from the separation zone to the dense fluidized mass.

2 more elements

A process for pyrolysis or carbonaceous materials comprising the steps of:

a. simultaneously introducing to the base of upwardly flowing fast fluidized bed contained within a substantially vertically disposed, open, cylindrical duct surrounded by a descending dense fluidized mass of particulate solids including particulate carbon containing solid residue comprising char and spent particulate source of heat maintained fluidized by an ascending stream of a stripping gas which is nondeleteriously reactive with respect to the products of pyrolysis and a particulate source of heat to contact and initiate pyrolysis of the carbonaceous material to yield within a pyrolysis time of from about 0.1 to about 5 seconds as products of pyrolysis pyrolytic vapor and particulate carbon containing solid residue comprising char, the weight ratio of the particulate source of heat to coal being from about 2 to about 20:1 and the temperature of the particulate source of heat being sufficient to raise the coal to a pyrolysis temperature of from about 600.degree. to about 1400.degree. F, while simultaneously maintaining a flow of solids surrounding dense fluidized mass upwardly along the inner surface of the duct to prevent contact of the agglomerative coal with the inner surface of the duct by discharging into the base of the duct upwardly along the inner surface of said duct a fluidizing gas which is nondeleteriously reactive with respect to pyrolysis products;
b. discharging (i) a portion of the particulate source of heat and particulate carbon containing solid residue resulting from pyrolysis over the top edge of the duct to the descending dense fluidized mass of particulate solids and (ii) a stream comprising a gaseous mixture of carrier gas, pyrolytic vapors, and entrained particulate solids including spent particulate solid source of heat and carbon containing solid residue from the top portion of the duct and through an outlet above the fluidized bed and separating the entrained solids from the gaseous mixture in a cyclone separation zone;
c. recovering hydrocarbons from the gaseous mixture;
d. cycling the separated entrained solids from the separation zone to the dense fluidized mass;
e. collecting solids comprising carbon containing solid residue in a stripping zone below the fast fluidized bed;
f. stripping hydrocarbons from the solids in the stripping zone with a stripping gas which is nondeleteriously reactive with respect to pyrolysis products;
and
g. withdrawing stripped solids from the stripping zone.

5 more elements

A reactor for pyrolysis of solid carbonaceous materials comprising:

a. an open, substantially vertically disposed duct having a first vertically oriented solids inlet and a second vertically oriented solids inlet positioned at the base thereof in open communication therewith and laterally spaced therefrom;
b. a gas inlet around the first and second solids inlet and in open communication with the base of said duct;
c. a vertically oriented outer vessel enclosing said duct in spaced relationship therefrom to form a substantially vertically disposed passageway therebetween;
d. means for introducing a particulate carbonaceous material to undergo pyrolysis upwardly through the first solids inlets;
e. means for introducing a particulate source of heat upwardly through the second solids inlet to pyrolyze the carbonaceous material to yield as products of pyrolysis pyrolytic vapor and carbon containing solids residue;
and
f. means for introducing a fluidizing gas to the gas inlet to fluidize a layer of particulate solids including the particulate source of heat moving along the inner surface of the duct, the solids entering the duct at the base thereof from the passageway between the duct and the outer vessel;
and
g. means for removing pyrolytic vapor and means for removing carbon containing solid residue from the outer vessel.

6 more elements

An apparatus for pyrolysis of solid carbonaceous materials comprising:

a. an open, vertically disposed cylindrical duct having a first and a second vertically oriented solids inlet positioned at the base thereof in open communication therewith and laterally spaced therefrom, wherein the first solids inlet comprises a tube and the second solids inlet comprises an annular region surrounding the tube only at the end portion of the tube;
b. a fluidizing gas inlet surrounding the first and second solids inlet in open communication with the base of said duct;
c. a vertically oriented outer vessel enclosing said duct in spaced relationship therefrom to form a vertically disposed passageway therebetween;
d. means for introducing a particulate carbonaceous material to undergo pyrolysis upwardly through the first solids inlet;
e. means for introducing a particulate source of heat upwardly through the second solids inlet to pyrolyze the carbonaceous material introduced through the first solids inlet to yield as products of pyrolysis pyrolytic vapor containing hydrocarbons and carbon containing solid residue;
f. means for introducing fluidizing gas to the gas inlet to fluidize a layer of particulate solids containing carbon containing solid residue and spent particulate source of heat moving along the inner surface of the duct, the solids entering the duct at the base thereof from the passageway between the duct and the outer vessel;
g. outlet means above the duct for removal of pyrolytic vapor and entrained solids from the outer vessel;
and
h. a solids outlet below the duct for withdrawal of carbon containing solid residue.

6 more elements

An apparatus for pyrolysis of agglomerative coals comprising:

a. an open, substantially vertically disposed cylindrical duct having a first and second solids inlet positioned at the base thereof in open communication therewith and laterally spaced therefrom, wherein the first solids inlet comprises a vertically disposed tube and the second solids inlet comprises an annular passageway between the first tube and a second vertically disposed tube coaxial with and surrounding the first tube only at the terminus portion of the first tube;
b. a fluidizing gas inlet around the first and second solids inlet and in open communication with the base of said duct;
c. a vertically oriented outer vessel enclosing said duct in spaced relationship therefrom to form a vertically disposed passageway therebetween;
d. a stripping gas inlet in open communication wiht the base of said passageway.
e. means for introducing a particulate carbonaceous material to undergo pyrolysis upwardly through the first solids inlet;
f. means for introducing a particulate source of heat upwardly through the second solids inlet to pyrolyze the carbonaceous material to yield as products of pyrolysis pyrolytic vapors containing hydrocarbons and carbon containing solid residue;
g. means for introducing fluidizing gas to the fluidizing gas inlet to fluidize a layer of particulate solids moving along the inner surface of the duct, the solids entering the duct at the base thereof from the passageway between the duct and the outer vessel;
h. means for introducing a stripping gas to the stripping gas inlet to fluidize solids descending through the passageway between the duct and the outer vessel towards the base of the duct to be fluidized by the fluidizing gas introduced to the fluidizing gas inlet;
i. outlet means above the duct for removal of pyrolytic vapor and entrained solids from the outer vessel comprising a vertically oriented duct tapering inwardly away from the duct;
j. means for separating the pyrolytic vapor from the entrained solids;
k. connection means from an outlet above the duct to the separation means;
l. means for transferring entrained solids separated in the separation means from the separation means to the passageway between the duct and the outer vessel;
m. a stripping chamber below and in open communication with the duct into which particulate carbon containing solid residue passes;
n. means for passing a stripping gas through the stripping chamber;
and
o. means for withdrawing particles from the stripping chamber.

13 more elements

Dependencies are inferred from the claim text.

patentgrep

Loading patent…

Abstract

a. simultaneously introducing upwardly to the base of an upwardly flowing fast fluidized bed contained within a substantially vertically disposed open duct, said open duct at least partially surrounded by a descending dense fluidized mass of particulate solids including particulate carbon containing solid residue of pyrolysis and spent particulate source of heat, a particulate carbonaceous material contained in a carrier gas which is nondeleteriously reactive with respect to the products of pyrolysis and a particulate source of heat to contact and pyrolyze the carbonaceous material, the introduced quantity of particulate solid source of heat being sufficient to raise the carbonaceous material to a pyrolysis temperature of at least about 600.degree. F to yield as products of pyrolysis pyrolytic vapor and particulate carbon containing solid residue, while simultaneously maintaining a flow of solids from the surrounding dense fluidized mass upwardly along the inner surface of the duct to prevent contact of the carbonaceous material with the inner surface of the duct;
b. discharging (i) at least a portion of the spent particulate source of heat and particulate carbon containing solid residue resulting from pyrolysis over the top end of the open duct to the descending dense fluidized mass of particulate solids and (ii) a stream comprising a gaseous mixture of carrier gas, pyrolytic vapor and entrained particulate solids including spent particulate solid source of heat and carbon containing solid residue from the upper portion of the duct and through an outlet above the fluidized bed;
c. separating the entrained solids from the gaseous mixture in a separation zone;
and
d. recovering hydrocarbon values from the gaseous mixture.

2 more elements