U.S. patent application number 14/553143 was filed with the patent office on 2015-03-19 for catalyst compositions and applications thereof.
This patent application is currently assigned to CORMETECH, INC.. The applicant listed for this patent is Chris E. Difrancesco, Raymond Oh, Christian Trefzger. Invention is credited to Chris E. Difrancesco, Raymond Oh, Christian Trefzger.
Application Number | 20150079334 14/553143 |
Document ID | / |
Family ID | 44513186 |
Filed Date | 2015-03-19 |
United States Patent
Application |
20150079334 |
Kind Code |
A1 |
Trefzger; Christian ; et
al. |
March 19, 2015 |
CATALYST COMPOSITIONS AND APPLICATIONS THEREOF
Abstract
In one aspect, structural catalyst bodies comprising one or more
gradients of catalytic material are provided herein. In some
embodiments, a structural catalyst body described herein comprises
an inner partition wall having a first surface and a second surface
opposite the first surface, the inner partition wall having a
gradient of catalytic material along the width of the inner
partition wall.
Inventors: |
Trefzger; Christian;
(Durham, NC) ; Difrancesco; Chris E.; (Durham,
NC) ; Oh; Raymond; (Durham, NC) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Trefzger; Christian
Difrancesco; Chris E.
Oh; Raymond |
Durham
Durham
Durham |
NC
NC
NC |
US
US
US |
|
|
Assignee: |
CORMETECH, INC.
Durham
NC
|
Family ID: |
44513186 |
Appl. No.: |
14/553143 |
Filed: |
November 25, 2014 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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13206497 |
Aug 9, 2011 |
8901033 |
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14553143 |
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61371971 |
Aug 9, 2010 |
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61371948 |
Aug 9, 2010 |
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Current U.S.
Class: |
428/117 ;
428/172; 502/305; 502/353 |
Current CPC
Class: |
B01D 2255/20769
20130101; B01D 2255/905 20130101; B01D 2255/1026 20130101; B01J
23/30 20130101; B01D 2255/20723 20130101; B01J 21/063 20130101;
B01J 35/04 20130101; B01D 2255/104 20130101; B01D 53/8665 20130101;
B01D 2255/1023 20130101; B01J 37/0201 20130101; B01J 23/22
20130101; B01D 2255/1021 20130101; B01D 2257/602 20130101; B01D
2255/106 20130101; B01D 2257/404 20130101; B01D 2257/302 20130101;
B01D 2255/1025 20130101; B01D 53/8609 20130101; B01D 53/9418
20130101; Y10T 428/24157 20150115; B01D 2255/20776 20130101; B01J
35/0006 20130101; B01D 53/8634 20130101; B01D 2257/406 20130101;
Y10T 428/24612 20150115; B01D 2255/1028 20130101; B01J 35/0073
20130101 |
Class at
Publication: |
428/117 ;
502/353; 502/305; 428/172 |
International
Class: |
B01J 23/30 20060101
B01J023/30 |
Claims
1. A structural catalyst body comprising: at least one inner
partition wall comprising a gradient of a bulk first catalytic
material along a width of the inner partition wall.
2. The structural catalyst body of claim 1, wherein the bulk first
catalytic material of the gradient decreases in concentration at
the periphery of the width of the inner partition wall.
3. The structural catalyst body of claim 1, wherein the bulk first
catalytic material of the gradient increases in concentration along
a central region of the width of the inner partition wall.
4. The structural catalyst body of claim 1, wherein the gradient of
the bulk first catalytic material has a profile substantially
symmetrical about a midpoint of the profile.
5. The structural catalyst body of claim 3, wherein the
concentration of the bulk first catalytic material at a point in
the central region of the width of the inner partition wall is at
least 1.3 times greater than a concentration of the bulk first
catalytic material at a peripheral point of the width of the first
surface.
6. The structural catalyst body of claim 3, wherein the
concentration of bulk first catalytic material at a point in the
central region of the width of the inner partition wall is at least
2 times greater than a concentration of the bulk first catalytic
material at a peripheral point of the width of the first
surface.
7. The structural catalyst body of claim 1 further comprising a
gradient of a bulk second catalytic material along a width of the
inner partition wall.
8. The structural catalyst body of claim 7, wherein the bulk second
catalytic material of the gradient decreases in concentration at
the periphery of the width of the inner partition wall.
9. The structural catalyst body of claim 7, wherein the bulk second
catalytic material of the gradient increases in concentration along
a central region of the width of the inner partition wall.
10. The structural catalyst body of claim 1, further comprising a
plurality of additional inner partition walls comprising a gradient
of bulk first catalytic material along a width of the inner
partition walls, the bulk first catalytic material increasing in
concentration along a central region of the width of the inner
partition walls wherein the concentration of the bulk first
catalytic material at a point in the central region is at least 1.3
times greater than a concentration of the bulk first catalytic
material at a peripheral point of the width of the inner partition
walls.
11. The structural catalyst body of claim 10, wherein the bulk
first catalytic material is operable for the selective catalytic
reduction of nitrogen oxides.
12. The structural catalyst body of claim 10, wherein the bulk
first catalytic material is selected from the group consisting of
V.sub.2O.sub.5, WO.sub.3, MoO.sub.3 and Ru.
13. The structural catalyst body of claim 10, further comprising a
gradient of bulk second catalytic material along the width of the
inner partition walls, the bulk second catalytic material
increasing in concentration along the central region of the width
of the inner partition walls wherein the concentration of the bulk
second catalytic material at a point in the central region is at
least 1.3 times greater than a concentration of the bulk second
catalytic material at a peripheral point of the width of the inner
partition walls.
14. The structural catalyst body of claim 13, wherein the bulk
second catalytic material is operable for the selective catalytic
reduction of nitrogen oxides.
15. The structural catalyst body of claim 13, wherein the bulk
second catalytic material is selected from the group consisting of
V.sub.2O.sub.5, WO.sub.3, MoO.sub.3 and Ru.
16. The structural catalyst body of claim 10, wherein greater than
50 percent of the inner partition walls of the structural catalyst
body comprise the gradient of the bulk first catalytic
material.
17. The structural catalyst body of claim 10, wherein greater than
90 percent of the inner partition walls of the structural catalyst
body comprise the gradient of the bulk first catalytic material.
Description
RELATED APPLICATION DATA
[0001] The present application is a divisional application pursuant
to 35 U.S.C. .sctn.120 of U.S. patent application Ser. No.
13/206,497 filed Aug. 9, 2011 which claims priority pursuant to 35
U.S.C. .sctn.119(e) to U.S. Provisional Patent Application Ser. No.
61/371,971, filed Aug. 9, 2010 and to U.S. Provisional Patent
Application Ser. No. 61/371,948, filed Aug. 9, 2010, each of which
is incorporated herein by reference in its entirety.
FIELD
[0002] The present invention relates to catalyst compositions and,
in particular, to catalyst structures for use in industrial or
commercial applications.
BACKGROUND
[0003] The role nitrogen oxides in the formation of acid rain,
tropospheric ozone and other environmental hazards has resulted in
the imposition of strict standards limiting the discharges of these
chemical species. To meet these standards, it is generally
necessary to remove at least part of these oxides present in the
exhaust gases from stationary or mobile combustion sources.
[0004] Denitration or selective catalytic reduction (SCR)
technology is commonly applied to combustion-derived flue gases for
removal of nitrogen oxides. The denitration reaction comprises the
reaction of nitrogen oxide species in the gases, such as nitrogen
oxide (NO) or nitrogen dioxide (NO.sub.2), with a nitrogen
containing reductant, such as ammonia or urea, resulting in the
production of diatomic nitrogen (N.sub.2) and water.
[0005] In addition to nitrogen oxides, sulfur dioxide (SO.sub.2) is
a chemical species often present in combustion-flue gases that
causes environmental concern. Sulfur dioxide present in fossil fuel
combustion flue-gases is partly oxidized to sulfur trioxide
(SO.sub.3) which reacts with water to form sulfuric acid. The
formation of sulfuric acid from the oxidation of sulfur dioxide in
combustion flue-gases can increase corrosion problems in downstream
equipment, can increase power costs associated with air pre-heaters
due to the increased temperature required to keep the
acid-containing flue-gas above its dew point, and can cause
increased opacity in the stack gases emitted to the atmosphere.
[0006] Catalyst systems for the removal of nitrogen oxides can
increase the amount of sulfur dioxide oxidation since catalytic
material utilized in selective catalytic reduction can additionally
effectuate the oxidation of sulfur dioxide. As a result, the
reduction in the nitrogen oxide content of a combustion flue-gas
can have an undesirable side-effect of increasing SO.sub.3
formation in the combustion flue-gas.
SUMMARY
[0007] In one aspect, catalyst bodies are described herein which,
in some embodiments, display heterogeneous distributions of
catalytic material. In some embodiments, catalyst bodies described
herein are operable for the selective catalytic reduction of
nitrogen oxides in a flue gas stream. Structural catalyst bodies
described herein, in some embodiments, can reduce SO.sub.2
oxidation during nitrogen oxide removal from a flue gas stream.
[0008] In some embodiments, a structural catalyst body described
herein comprises at least one inner partition wall comprising first
surface and a second surface opposite the first surface, the inner
partition wall having a gradient of a first catalytic material
along a width of the first surface. In some embodiments, the first
catalytic material of the gradient decreases in amount at the
periphery of the width of the first surface. In some embodiments,
the first catalytic material of the gradient increases in amount
along a central region of the width of the first surface. In some
embodiments, a gradient of a first catalytic material along the
width of the first surface of the inner partition wall has a
profile symmetrical or substantially symmetrical about the midpoint
of the profile. A structural catalyst body, in some embodiments,
further comprises a gradient of the first catalytic material along
a width of the second surface. In some embodiments, the first
catalytic material of the gradient decreases in amount at the
periphery of the width of the second surface. The first catalytic
material of the gradient, in some embodiments, increases in amount
along a central region of the width of the second surface. In some
embodiments, the gradient profile of the first catalytic material
along the width of the second surface is symmetrical or
substantially symmetrical to the gradient profile of the first
catalytic material along the width of the first surface.
[0009] In some embodiments, a structural catalyst body described
herein further comprises a gradient of the first catalytic material
along a length of the first surface of the inner partition wall. A
gradient of the first catalytic material along the length of the
first surface of the inner partition wall, in some embodiments,
comprises a greater amount of the first catalytic material at a
first end of the inner partition wall in comparison with an amount
of the first catalytic material at a second end of the inner
partition wall, the second end opposite the first end.
[0010] In some embodiments, a structural catalyst body described
herein further comprises a gradient of the first catalytic material
along a length of the second surface of the inner partition wall. A
gradient of the first catalytic material along the length of the
second surface of the inner partition wall, in some embodiments,
comprises a greater amount of the first catalytic material at a
first end of the inner partition wall in comparison with an amount
of the first catalytic material at a second end of the inner
partition wall, the second end opposite the first end. In some
embodiments, the gradient profile of the first catalytic material
along the length of the second surface of the inner partition wall
is symmetrical or substantially symmetrical to the gradient profile
of the first catalytic material along the length of the first
surface of the inner partition wall.
[0011] In some embodiments, the first end of the inner partition
wall corresponds to the fluid stream inlet side of the structural
catalyst body, and the second end corresponds to the fluid stream
outlet side of the structural catalyst body. In some embodiments,
the first end of the inner partition wall corresponds to the fluid
stream outlet side of the structural catalyst body, and the second
end corresponds to the fluid stream inlet of the structural
catalyst body.
[0012] In some embodiments, a structural catalyst body described
herein comprises a gradient of bulk first catalytic material along
a width of at least one inner partition wall. In some embodiments,
bulk first catalytic material of the gradient decreases in
concentration at the periphery of the width of the inner partition
wall. In some embodiments, bulk first catalytic material increases
in concentration along a central region of the width of the inner
partition wall. In some embodiments, a gradient of bulk first
catalytic material along the width of the inner partition wall has
a profile symmetrical or substantially symmetrical about the
midpoint of the profile.
[0013] In some embodiments, a structural catalyst body described
herein comprises a gradient of bulk first catalytic material along
a length of at least one inner partition wall. In some embodiments,
a gradient of bulk first catalytic material along a length of an
inner partition wall comprises a greater concentration of the bulk
first catalytic material at a first end of the inner partition wall
in comparison with an concentration of the bulk first catalytic
material at a second end of the inner partition wall, the second
end opposite the first end. As described herein, in some
embodiments, the first end of the inner partition wall corresponds
to the fluid stream inlet side of the structural catalyst body, and
the second end corresponds to the fluid stream outlet side of the
structural catalyst body. In some embodiments, the first end of the
inner partition wall corresponds to the fluid stream outlet side of
the structural catalyst body, and the second end corresponds to the
fluid stream inlet of the structural catalyst body.
[0014] A structural catalyst body described herein, in some
embodiments, further comprises at least one additional inner
partition wall comprising one or more gradients of the first
catalytic material described herein for an inner partition wall. In
some embodiments, the at least one additional inner partition wall
comprises a first surface and a second surface and a gradient of
the first catalytic material along a width of the first surface. In
some embodiments, the at least one additional inner partition wall
further comprises a gradient of the first catalytic material along
a width of the second surface.
[0015] Moreover, in some embodiments, the at least one additional
inner partition wall comprises a gradient of bulk first catalytic
material along a width of the additional inner partition wall. In
some embodiments, the at least one additional inner partition wall
comprises a gradient of bulk first catalytic material along a
length of the inner partition wall.
[0016] The at least one additional inner partition wall, in some
embodiments, comprises a gradient of the first catalytic material
along the length of the first surface and/or second surface.
[0017] In some embodiments, the at least one additional inner
partition wall comprises a plurality of additional inner partition
walls such that greater than about 50 percent of the inner
partition walls of the structural catalyst body comprise one or
more gradients of the first catalytic material described herein. In
some embodiments, greater than about 70 or greater than about 90
percent of the inner partition walls of the structural catalyst
body comprise one or more gradients of the first catalytic material
described herein. In some embodiments, greater than about 95
percent of the inner partition walls of the structural catalyst
body comprise one or more gradients of the first catalytic material
described herein.
[0018] In some embodiments, inner partition walls of a structural
catalyst body described herein intersect to form one or more
centerposts. In some embodiments, a structural catalyst body
described herein comprises a gradient of bulk first catalytic
material between a centerpost and at least one inner partition wall
connected to the centerpost. In some embodiments, for example, the
at least one inner partition wall comprises a greater concentration
of a bulk first catalytic material than the centerpost. In some
embodiments, a structural catalyst body described herein comprises
a gradient of bulk first catalytic material between a centerpost
and a plurality of inner partition walls connected to the
centerpost. In some embodiments, each of the inner partition walls
connected to the centerpost comprises a greater concentration of a
bulk first catalytic material than the centerpost.
[0019] In some embodiments, inner partition walls define a
plurality of flow channels or cells which extend through the
structural catalyst body. In some embodiments, inner partition
walls are at least partially surrounded by an outer peripheral wall
or structure. In some embodiments, an outer peripheral wall is
continuous or integral with one or more inner partition walls, such
as in some honeycomb-like structural catalyst bodies. In some
embodiments, an outer peripheral wall is part of a containment
structure in which the inner partition walls are disposed, such as
in the arrangement of plate catalyst elements or corrugated
catalyst elements in a containment structure.
[0020] In some embodiments wherein the outer peripheral wall
comprises bulk first catalytic material, inner partition walls of a
structural catalyst body comprise more bulk first catalytic
material than the outer peripheral wall. Moreover, in some
embodiments, an interior surface of an outer peripheral wall
comprises one or more gradients of the first catalytic material
described herein for an inner partition wall. In some embodiments,
outer surfaces of an outer peripheral wall do not display one or
more gradients of the first catalytic material described herein. In
some embodiments, an interior surface of an outer peripheral wall
comprises a greater amount of first catalytic material than an
exterior surface of the inner partition wall.
[0021] In some embodiments, a structural catalyst body described
herein further comprises a gradient of a second catalytic material
along the width of the first surface of at least one inner
partition wall. In some embodiments, a gradient of a second
catalytic material along the width of the first surface of at least
one inner partition wall can have any of the properties recited
herein for a gradient of the first catalytic material along the
width of the first surface of an inner partition wall.
[0022] In some embodiments, a structural catalyst body described
herein further comprises a gradient of a second catalytic material
along the width of the second surface of at least one inner
partition wall. In some embodiments, a gradient of a second
catalytic material along the width of the second surface of the
inner partition wall can have any of the properties recited herein
for a gradient of the first catalytic material along the width of
the second surface of an inner partition wall.
[0023] In some embodiments, a structural catalyst body described
herein further comprises a gradient of second catalytic material
along a length of the first surface of the at least one inner
partition wall. In some embodiments, a gradient of at a second
catalytic material along a length of the first surface of the inner
partition wall can have any of the properties recited herein for a
gradient of the first catalytic material along a length of the
first surface of the inner partition wall.
[0024] In some embodiments, a structural catalyst body described
herein further comprises a gradient of a second catalytic material
along a length of the second surface of at least one inner
partition wall. In some embodiments, a gradient of a second
catalytic material along a length of the second surface of the
inner partition wall can have any of the properties recited herein
for a gradient of the first catalytic material along a length of
the second surface of an inner partition wall.
[0025] In some embodiments, a structural catalyst body described
herein further comprises a gradient of a bulk second catalytic
material along the width of at least one inner partition wall. In
some embodiments, a gradient of a bulk second catalytic material
can have any of the properties recited herein for a gradient of a
bulk first catalytic material along a width of the inner partition
wall.
[0026] In some embodiments, a structural catalyst body described
herein further comprises a gradient of a bulk second catalytic
material along a length of at least one inner partition wall. In
some embodiments, a gradient of a bulk second catalytic material
along a length of an inner partition wall can have any of the
properties recited herein for a gradient of a bulk first catalytic
material along a length of an inner partition wall.
[0027] In some embodiments, a structural catalyst body described
herein further comprises a gradient of a second catalytic material
along the width of the first surface of at least one additional
inner partition wall. In some embodiments, a gradient of a second
catalytic material along the width of the first surface of at least
one additional inner partition wall can have any of the properties
recited herein for a gradient of a first catalytic material along
the width of the first surface of an inner partition wall.
[0028] In some embodiments, a structural catalyst body described
herein further comprises a gradient of a second catalytic material
along the width of the second surface of at least one additional
inner partition wall. In some embodiments, a gradient of a second
catalytic material along the width of the second surface of at
least one additional inner partition wall can have any of the
properties recited herein for a gradient of a first catalytic
material along the width of the second surface of an inner
partition wall.
[0029] In some embodiments, a structural catalyst body described
herein further comprises a gradient of a bulk second catalytic
material along the width of at least one additional inner partition
wall. In some embodiments, a gradient of bulk second catalytic
material along the width of at least one additional inner partition
wall can have any of the properties recited herein for a gradient
of a bulk first catalytic material along the width of an inner
partition wall.
[0030] In some embodiments, a structural catalyst body described
herein further comprises a gradient of a bulk second catalytic
material along a length of at least one additional inner partition
wall. In some embodiments, a gradient of a bulk second catalytic
material along the length of at least one additional inner
partition wall can have any of the properties recited herein for a
gradient of a bulk first catalytic material along a length of an
inner partition wall.
[0031] In some embodiments, a structural catalyst body described
herein further comprises a gradient of a second catalytic material
along a length of the first and/or second surface of at least one
additional inner partition wall. In some embodiments, a gradient of
a second catalytic material along a length of the first and/or
second surface of at least one additional inner partition wall can
have any of the properties recited herein for a gradient of the
first catalytic material along a length of the first/and or second
surface of an inner partition wall.
[0032] In some embodiments, a structural catalyst body described
herein comprises a gradient of a bulk second catalytic material
between a centerpost and at least one inner partition wall
connected to the centerpost. In some embodiments, for example, at
least one inner partition wall comprises a greater concentration of
a bulk second catalytic material than the centerpost. In some
embodiments, a structural catalyst body described herein comprises
a gradient of a bulk second catalytic material between a centerpost
and a plurality of inner partition walls connected to the
centerpost. In some embodiments, each of the inner partition walls
connected to the centerpost comprises a greater concentration of a
bulk second catalytic material than the centerpost.
[0033] Moreover, in some embodiments, an outer peripheral wall
further comprises a bulk second catalytic material, wherein inner
partition walls of the structural catalyst body comprise a greater
amount of the bulk second catalytic material than the outer
peripheral wall. In some embodiments, an interior surface of an
outer peripheral wall further comprises one or more gradients of
the second catalytic material described herein for an inner
partition wall.
[0034] In some embodiments, a structural catalyst body further
comprises a gradient of at least one additional catalytic material.
A gradient of at least one additional catalytic material can
comprise any construction and/or location in a structural catalyst
body described herein for a gradient of a first catalytic material
or a second catalytic material.
[0035] Structural catalyst bodies described herein, in some
embodiments, comprise virgin structural catalyst bodies. In some
embodiments, structural catalyst bodies described herein comprise
used or regenerated structural catalyst bodies. In some
embodiments, structural catalyst bodies described herein comprise
honeycomb-like structural catalyst bodies, plate catalyst bodies or
corrugated catalyst bodies.
[0036] In another aspect, a catalyst module is described herein
comprising a framework and a plurality of structural catalyst
bodies disposed in the framework, the structural catalyst bodies
comprising a gradient of a first catalytic material along the width
of a surface of at least one inner partition wall as described
herein. In some embodiments, the catalytic activity of the catalyst
bodies of the module is substantially uniform. In being
substantially uniform, catalytic activity between catalyst bodies
of the module, in some embodiments, varies less than about 20%. In
some embodiments, in being substantially uniform, catalytic
activity between catalyst bodies of the module varies less than
10%. In some embodiments, in being substantially uniform, catalytic
activity between catalyst bodies of the module varies less than 5%.
In some embodiments, catalytic activity comprises the selective
catalytic reduction of nitrogen oxides, the oxidation of mercury or
the oxidation of ammonia or combinations thereof.
[0037] In some embodiments, sulfur dioxide oxidation activity of
catalyst bodies of the module is substantially uniform. In being
substantially uniform, sulfur dioxide oxidation activity between
catalyst bodies of the module, in some embodiments, varies less
than 40%. In some embodiments, in being substantially uniform,
sulfur dioxide oxidation activity between catalyst bodies of the
module varies less than 20%. In some embodiments, in being
substantially uniform, sulfur dioxide oxidation activity between
catalyst bodies of the module varies less than 10%.
[0038] Moreover, in some embodiments, catalyst bodies of a module
comprise one or more catalytic gradients described herein in
addition to a gradient of a first catalytic material along the
width of a surface of at least one inner partition wall. In some
embodiments, for example, catalyst bodies of the module also
comprise a gradient of bulk first catalytic material along a width
and/or length of at least one inner partition as described herein.
In some embodiments, catalyst bodies of a module comprise one or
more gradients of a second catalytic material described herein.
[0039] In another aspect, at least one catalyst layer of a
catalytic reactor is described herein, the catalyst layer
comprising a plurality of structural catalyst bodies, the
structural catalyst bodies comprising a gradient of catalytic
material along a width of a surface of at least one inner partition
wall as described herein. In some embodiments, the catalytic
activity of the structural catalyst bodies of the catalyst layer is
substantially uniform. In being substantially uniform, in some
embodiments, catalytic activity between catalyst bodies of the
catalyst layer varies less than about 20%. In some embodiments, in
being substantially uniform, catalytic activity between catalyst
bodies of the catalyst layer varies less than about 10%. In some
embodiments, in being substantially uniform, catalytic activity
between catalyst bodies of the catalyst layer varies less than
about 5%. In some embodiments, catalytic activity comprises the
selective catalytic reduction of nitrogen oxides, the oxidation of
mercury or the oxidation of ammonia or combinations thereof.
[0040] In some embodiments, sulfur dioxide oxidation activity of
catalyst bodies of the catalyst layer is substantially uniform. In
being substantially uniform, sulfur dioxide oxidation activity
between catalyst bodies of the catalyst layer, in some embodiments,
varies less than 40%. In some embodiments, in being substantially
uniform, sulfur dioxide oxidation activity between catalyst bodies
of the catalyst layer varies less than 20%. In some embodiments, in
being substantially uniform, sulfur dioxide oxidation activity
between catalyst bodies of the catalyst layer varies less than
10%.
[0041] In some embodiments, catalyst bodies of a catalyst layer
comprise one or more catalytic gradients described herein in
addition to the gradient of a first catalytic material along the
width of a surface of at least one inner partition wall. In some
embodiments, for example, catalyst bodies of a catalyst layer also
comprise a gradient of bulk first catalytic material along a width
and/or length of at least one inner partition as described herein.
In some embodiments, catalyst bodies of a catalyst layer comprise
one or more gradients of a second catalytic material described
herein. In some embodiments, catalyst bodies of a catalyst layer
are arranged into one or more modules.
[0042] In another aspect, methods of treating a fluid stream, such
as a flue gas or combustion gas stream, are described herein. In
some embodiments, a method of treating a fluid stream comprises
providing a structural catalyst body comprising at least one inner
partition wall comprising a first surface and a second surface
opposite the first surface, the inner partition wall having a
gradient of a first catalytic material along a width of the first
surface, passing the fluid stream through the structural catalyst
body and catalytically reacting at least one chemical species in
the fluid stream. In some embodiments, the fluid stream is flowed
through one or more flow channels of the structural catalyst body.
In some embodiments of methods described herein, the structural
catalyst body can have any gradient of a first catalytic material
and/or a second catalytic material described herein.
[0043] In some embodiments, catalytically reacting at least one
chemical species in the fluid stream comprises catalytically
reducing nitrogen oxides in the fluid stream. In some embodiments,
catalytically reacting at least one chemical species in the fluid
stream comprises oxidizing ammonia and/or mercury in the fluid
stream.
[0044] In some embodiments of methods of treating a fluid stream,
oxidation of sulfur dioxide to sulfur trioxide in the fluid stream
is reduced. In one embodiment, for example, oxidation of sulfur
dioxide is reduced during the selective catalytic reduction of
nitrogen oxides in a fluid stream by a structural catalyst body
described herein.
[0045] In some embodiments, the catalyst body is part of a module
comprising a plurality of catalyst bodies described herein, where
the fluid stream is passed into the module and through the catalyst
bodies. In some embodiments, the module is part of a catalytic
layer of a catalytic reactor.
[0046] In another aspect, methods of producing structural catalyst
bodies described herein are provided. In some embodiments, a method
of producing a structural catalyst body comprises providing a
catalyst support comprising at least one inner partition wall
comprising a first surface and a second surface opposite the first
surface, impregnating the at least one inner partition wall with a
solution comprising a first catalytic material and drying the at
least one inner partition wall in a manner to establish a gradient
of the first catalytic material along a width of the first surface.
In some embodiments, the first catalytic material of the gradient
decreases in amount at the periphery of the width of the first
surface. In some embodiments, the first catalytic material of the
gradient increases in amount along a central region of the width of
the first surface.
[0047] In some embodiments, a gradient of the first catalytic
material is also established along a width of the second surface.
In some embodiments, the first catalytic material of the gradient
decreases in amount at the periphery of the width of the second
surface. The first catalytic material of the gradient, in some
embodiments, increases in amount along a central region of the
width of the second surface. In some embodiments, the gradient
profile of the first catalytic material along the width of the
second surface is symmetrical or substantially symmetrical to the
gradient profile of the first catalytic material along the width of
the first surface.
[0048] In some embodiments, the at least one inner partition wall
of the structural catalyst support is dried in a manner to
establish a gradient of bulk first catalytic material along a width
of the inner partition wall. In some embodiments, bulk first
catalytic material of the gradient decreases in concentration at
the periphery of the width of the inner partition wall. In some
embodiments, bulk first catalytic material increases in
concentration along a central region of the width of the inner
partition wall. In some embodiments, a gradient of a bulk first
catalytic material along the width of the inner partition wall has
a profile symmetrical or substantially symmetrical about the
midpoint of the profile.
[0049] In some embodiments, the at least one inner partition wall
of the structural catalyst support is dried in a manner to
establish a gradient of the first catalyst material along a length
of the first surface of the inner partition wall. A gradient of the
first catalytic material along the length of a first surface of the
inner partition wall, in some embodiments, comprises a greater
amount of the first catalytic material at a first end of the inner
partition wall in comparison with an amount of the first catalytic
material at a second end of the inner partition wall, the second
end opposite the first end.
[0050] In some embodiments, a gradient of the first catalytic
material is also established along a length of the second surface
of the inner partition wall. A gradient of the first catalytic
material along the length of the second surface of the inner
partition wall, in some embodiments, comprises a greater amount of
the first catalytic material at a first end of the inner partition
wall in comparison with an amount of the first catalytic material
at a second end of the inner partition wall, the second end
opposite the first end. In some embodiments, the gradient profile
of the first catalytic material along the length of the second
surface of the inner partition wall is symmetrical or substantially
symmetrical to the gradient profile of the first catalytic material
along the length of the first surface of the inner partition
wall.
[0051] In some embodiments, the first end of the inner partition
wall corresponds to the fluid stream inlet side of the structural
catalyst body and the second end corresponds to the fluid stream
outlet side of the structural catalyst body. Alternatively, in some
embodiments, the first end of the inner partition wall corresponds
to the outlet side of the structural catalyst body, and the second
end corresponds to the fluid stream inlet side.
[0052] In some embodiments, the at least one inner partition wall
of a structural catalyst body described herein is dried in a manner
to establish a gradient of a bulk first catalytic material along a
length of the inner partition wall. In some embodiments, a gradient
of a first bulk catalytic material along a length of the inner
partition wall comprises a greater concentration of the bulk first
catalytic material at a first end of the inner partition wall in
comparison with a concentration of the bulk first catalytic
material at a second end of the inner partition wall, the second
end opposite the first end.
[0053] In some embodiments of methods described herein, the
structural catalyst body comprises a plurality of inner partition
walls such that the inner partition walls are impregnated with a
solution comprising the first catalytic material and dried in a
manner to establish a gradient of the of the first catalytic
material along a width and/or length of one or more surfaces of the
inner partition walls. In some embodiments, the inner partition
walls are dried in a manner to establish a gradient of a bulk first
catalytic material along a width and/or length of the inner
partition walls.
[0054] In some embodiments, inner partition walls of a structural
catalyst body produced according to methods described herein
intersect to form one or more centerposts. In some embodiments, at
least one centerpost is impregnated with a solution comprising the
first catalytic material and dried in a manner to establish a
gradient of bulk first catalytic material between the centerpost
and at least one of the inner partition walls. In some embodiments,
for example, at least one inner partition wall comprises a greater
concentration of bulk first catalytic material than the centerpost.
In some embodiments, each of the inner partition walls connected to
the centerpost comprises a greater concentration of bulk first
catalytic material than the centerpost.
[0055] In some embodiments of methods described herein, the
impregnating solution further comprises a second catalytic
material. In some embodiments, a gradient of bulk metal or metal
oxide second catalytic material is established along a width of the
inner partition wall. Alternatively, in some embodiments, at least
one inner partition wall of a structural catalyst body comprising
one or more gradients of the first catalytic material described
herein is further impregnated with a solution comprising a metal or
metal oxide second catalytic material and dried in a manner to
establish a gradient of the metal or metal oxide second catalytic
material along a width of the first surface and/or second surface
of the inner partition wall. In some embodiments, a gradient of
bulk metal or metal oxide second catalytic material is established
along a width of the inner partition wall.
[0056] In some embodiments, the second catalytic material of the
gradient decreases in amount at the periphery of the width of the
first surface. In some embodiments, the second catalytic material
of the gradient increases in amount along a central region of the
width of the first surface.
[0057] In some embodiments, a gradient of the second catalytic
material is also established along a width of the second surface of
the inner partition wall. In some embodiments, the second catalytic
material of the gradient decreases in amount at the periphery of
the width of the second surface. The second catalytic material of
the gradient, in some embodiments, increases in amount along a
central region of the width of the second surface. In some
embodiments, the gradient profile of the second catalytic material
along the width of the second surface is symmetrical or
substantially symmetrical to the gradient profile of the second
catalytic material along the width of the first surface.
[0058] In some embodiments, a gradient of the second catalytic
material is also established along a length of the first surface of
the inner partition wall. A gradient of the second catalytic
material along a first surface of the inner partition wall, in some
embodiments, comprises a greater amount of the second catalytic
material at a first end of the inner partition wall in comparison
with an amount of the second catalytic material at a second end of
the inner partition wall, the second end opposite the first
end.
[0059] In some embodiments, a gradient of the second catalytic
material is also established along a length of the second surface
of the inner partition wall. A gradient of the second catalytic
material along the length of the second surface of the inner
partition wall, in some embodiments, comprises a greater amount of
the second catalytic material at a first end of the inner partition
wall in comparison with an amount of the second catalytic material
at a second end of the inner partition wall, the second end
opposite the first end. In some embodiments, the gradient profile
of the second catalytic material along the length of the second
surface of the inner partition wall is symmetrical or substantially
symmetrical to the gradient profile of the second catalytic
material along the length of the first surface of the inner
partition wall.
[0060] In some embodiments, a gradient of bulk second catalytic
material is also established along a width of the inner partition
wall. In some embodiments, bulk second catalytic material of the
gradient decreases in concentration at the periphery of the width
of the inner partition wall. In some embodiments, bulk second
catalytic material increases in concentration along a central
region of the width of the inner partition wall. In some
embodiments, a gradient of bulk second catalytic material along the
width of the inner partition wall has a profile symmetrical or
substantially symmetrical about the midpoint of the profile.
[0061] In some embodiments, drying the at least one inner partition
wall of a structural catalyst body described herein also
establishes a gradient of a bulk second catalytic material along a
length of the inner partition wall. In some embodiments, a gradient
of a bulk second catalytic material along a length of the inner
partition wall comprises a greater concentration of the bulk second
catalytic material at a first end of the inner partition wall in
comparison with a concentration of the bulk second catalytic
material at a second end of the inner partition wall, the second
end opposite the first end.
[0062] Moreover, in some embodiments of methods described herein, a
gradient of the second catalytic material is also established along
a width and/or length of one or more surfaces of a plurality of
inner partition walls of the structural catalyst body. In some
embodiments, a gradient of bulk second catalytic material is also
established along a width and/or length of a plurality of inner
partition walls of the structural catalyst body.
[0063] In some embodiments, at least one centerpost of a structural
catalyst body is impregnated with the solution further comprising
the second catalytic material, and drying the structural catalyst
body also establishes a gradient of bulk second catalytic material
between the centerpost and at least one of the inner partition
walls forming the centerpost. In some embodiments, for example, at
least one inner partition wall comprises a greater concentration of
bulk second catalytic material than the centerpost. In some
embodiments, each of the inner partition walls forming the
centerpost comprises a greater concentration of bulk second
catalytic material than the centerpost.
[0064] Additionally, in some embodiments, the outer peripheral wall
of a structural catalyst body described herein is impregnated with
the second catalytic material. In some embodiments wherein the
outer peripheral wall comprises bulk second catalytic material,
inner partition walls of the structural catalyst body comprise a
greater concentration of bulk second catalytic material than the
outer peripheral wall.
[0065] In some embodiments, first and/or second catalytic material
of gradients of structural catalyst bodies produced according to
methods described herein comprise one or more transition metals. In
some embodiments, transition metals of the first and/or second
catalytic material comprise vanadium, tungsten, molybdenum,
platinum, palladium, ruthenium, rhodium, rhenium, iron, gold,
silver, copper or nickel or alloys or oxides thereof. In some
embodiments, the first and/or second catalytic material of
gradients of structural catalyst bodies described herein are
suitable for SCR applications and processes. In some embodiments,
for example, the first and/or second catalytic material comprise
V.sub.2O.sub.5, WO.sub.3 or MoO.sub.3 or mixtures thereof. In some
embodiments, the first and/or second catalytic material comprise
one or more precursors for forming a catalytic material suitable
for SCR applications. In some embodiments, for example, the first
and/or second catalytic material comprise one or more precursors
for forming V.sub.2O.sub.5, WO.sub.3 or MoO.sub.3 or mixtures
thereof.
[0066] In some embodiments, drying inner partition walls and/or
centerposts of a structural catalyst support comprises flowing a
gas over surfaces of the inner partition walls and/or centerposts
at a rate and/or temperature sufficient to establish one or more
gradients of the first catalytic material and/or second catalytic
material described herein. Flowing a gas over surfaces of the inner
partition walls and/or centerposts to establish one or more
gradients of the first catalytic material and/or second catalytic
material described herein can be administered in any manner not
inconsistent with the objectives of the present invention. In some
embodiments, gas is flowed over all or substantially all of the
inner partition walls and/or centerposts of a structural catalyst
support in an even or substantially even manner.
[0067] Additionally, in some embodiments, the impregnation solution
of a method described herein further comprises at least one
additional catalytic material. In such embodiments, drying the
structural catalyst body can provide one or more gradients of the
additional catalytic material having a construction and/or location
on the structural catalyst body consistent with any gradient of the
first and/or second catalytic material described herein.
[0068] In some embodiments, a structural catalyst support is
virgin. A virgin structural catalyst support, in some embodiments,
has not been used or previously installed into a catalytic reactor
for conducting catalytic reactions in a fluid stream.
[0069] In some embodiments, a structural catalyst support is used.
A used structural catalyst support, in some embodiments, has been
previously installed in a catalytic reactor for conducting
catalytic reactions in a fluid stream. In some embodiments, a used
catalyst support is part of a structural catalyst body in need of
regeneration.
[0070] In some embodiments, virgin or used structural catalyst
supports comprise honeycomb-like structural supports, plate
structural supports or corrugated structural supports.
[0071] In some embodiments of methods described herein, structural
catalyst supports comprising a plurality of inner partition walls
are arranged in the framework of a catalyst module. In such
embodiments, the catalyst module comprising the structural catalyst
supports can be immersed in the solution of catalytic material to
impregnate the inner partition walls and/or centerposts of the
structural catalyst supports with catalytic material.
[0072] In some embodiments, the structural catalyst supports
impregnated with a solution of the first catalytic material are
dried while remaining the framework of the catalyst module to
establish one or more gradients of the first catalytic material
described herein. In some embodiments, the impregnation solution
further comprises a second catalytic material wherein drying the
structural catalyst supports while remaining in the framework of
the catalyst module also establishes one or more gradients of the
second catalytic material as described herein. In some embodiments,
for example, a gas is flowed through the module and over surfaces
of the inner partition walls and/or centerposts of the structural
catalyst supports at a rate and/or temperature sufficient to
establish one or more gradients of the first and/or second
catalytic material described herein. In some embodiments, the gas
is flowed evenly or substantially evenly through the structural
catalyst supports arranged in the framework of the module such that
the catalytic activity of the resulting structural catalyst bodies
is substantially uniform across the module. In being substantially
uniform, catalytic activity between catalyst bodies in the module,
in some embodiments, varies less than about 20%. In some
embodiments, in being substantially uniform, catalytic activity
between catalyst bodies of the module varies less than 10%. In some
embodiments, in being substantially uniform, catalytic activity
between catalyst bodies of the module varies less than 5%. In some
embodiments, catalytic activity comprises the selective catalytic
reduction of nitrogen oxides, the oxidation of mercury or the
oxidation of ammonia or combinations thereof.
[0073] In some embodiments, sulfur dioxide oxidation activity of
catalyst bodies of the module is substantially uniform across the
module. In being substantially uniform, sulfur dioxide oxidation
activity between catalyst bodies of the module, in some
embodiments, varies less than 40%. In some embodiments, in being
substantially uniform, sulfur dioxide oxidation activity between
catalyst bodies of the module varies less than 20%. In some
embodiments, in being substantially uniform, sulfur dioxide
oxidation activity between catalyst bodies of the module varies
less than 10%.
[0074] In some embodiments, gradients of first and/or second
catalytic material produced according to the forgoing methods can
have any of the structural and/or compositional properties
described herein for the gradients of the first and/or second
catalytic material.
[0075] These and other embodiments are described in greater detail
in the detailed description which follows.
BRIEF DESCRIPTION OF THE DRAWINGS
[0076] FIG. 1 illustrates gradient profiles of first and second
catalytic materials along the width of the surface of an inner
partition wall of a structural catalyst body according to one
embodiment described herein.
[0077] FIG. 2 illustrates a structural catalyst body according to
one embodiment described herein.
[0078] FIG. 3 illustrates a cross-section of a portion of a
structural catalyst body according to one embodiment described
herein.
[0079] FIG. 4 illustrates catalytic activity testing of a
structural catalyst body according to one embodiment described
herein in comparison to a prior structural catalyst body.
[0080] FIG. 5 provides a table detailing structural catalyst bodies
having various gradient composition according to some embodiments
described herein.
[0081] FIG. 6 illustrates a cross-section of a portion of a
corrugated structural catalyst body according to one embodiment
described herein.
DETAILED DESCRIPTION
[0082] The present invention can be understood more readily by
reference to the following detailed description, examples and
drawings and their previous and following descriptions. Elements,
apparatus and methods of the present invention, however, are not
limited to the specific embodiments presented in the detailed
description, examples and drawings. It should be recognized that
these embodiments are merely illustrative of the principles of the
present invention. Numerous modifications and adaptations will be
readily apparent to those of skill in the art without departing
from the spirit and scope of the invention.
[0083] Moreover, all ranges disclosed herein are to be understood
to encompass any and all subranges subsumed therein. For example, a
stated range of "1 to 10" should be considered to include any and
all subranges between (and inclusive of) the minimum value of 1 and
the maximum value of 10; that is, all subranges beginning with a
minimum value of 1 or more, e.g. 1 to 6.1, and ending with a
maximum value of 10 or less, e.g., 5.5 to 10. Additionally, any
reference referred to as being "incorporated herein" is to be
understood as being incorporated in its entirety.
[0084] It is further noted that, as used in this specification, the
singular forms "a," "an," and "the" include plural referents unless
expressly and unequivocally limited to one referent.
[0085] In one aspect, catalyst bodies are described herein which,
in some embodiments, display heterogeneous distributions of
catalytic material. In some embodiments, catalyst bodies described
herein are operable for the selective catalytic reduction of
nitrogen oxides in a flue gas stream.
[0086] In some embodiments, a structural catalyst body described
herein comprises at least one inner partition wall comprising a
first surface and a second surface opposite the first surface, the
inner partition wall having a gradient of a first catalytic
material along a width of the first surface. In some embodiments,
the first catalytic material of the gradient decreases in amount at
the periphery of the width of the first surface.
[0087] In some embodiments, the surface of an inner partition wall
of a structural catalyst body described herein includes a portion
of the inner partition wall up to a depth of about 100 .mu.m. In
some embodiments, the surface of an inner partition wall includes a
portion of the inner partition wall up to a depth of about 50 .mu.m
or up to about 25 .mu.m. In some embodiments, the surface of an
inner partition wall includes a portion of the inner partition wall
up to a depth of about 10 .mu.m or up to about 5 .mu.m.
[0088] In some embodiments, the first catalytic material of the
gradient increases in amount along a central region of the width of
the first surface. In some embodiments, the amount of the first
catalytic material in a central region of the width of the first
surface exceeds the amount of the first catalytic material at the
periphery of the width of the first surface. In some embodiments,
the amount of the first catalytic material at a point in a central
region of the width of the first surface is greater than the amount
of the first catalytic material at a point at the periphery of the
width of the first surface.
[0089] In some embodiments, the amount of the first catalytic
material at a point in a central region of the width of the first
surface is at least 1.1 times greater or 1.3 times greater than the
amount of the first catalytic material at a point at the periphery
of the width of the first surface. In some embodiments, the amount
of the first catalytic material at a point in a central region of
the width of the first surface is at least 1.5 times or at least 2
times greater than the amount of the first catalytic material at a
point at the periphery of the width of the first surface. In some
embodiments, the amount of the first catalytic material at a point
in a central region of the width of the first surface is at least 3
times or at least 3.5 times greater than the amount of the first
catalytic material at a point at the periphery of the width of the
first surface. In some embodiments, the amount of the first
catalytic material at a point in a central region of the width of
the first surface is at least 4 times or at least 4.5 times greater
than the amount of the first catalytic material at a point at the
periphery of the width of the first surface. In some embodiments,
the amount of the first catalytic material at a point in a central
region of the width of the first surface is at least 5 times or at
least 10 times greater than the amount of the first catalytic
material at a point at the periphery of the width of the first
surface. In some embodiments, an amount of the first catalytic
material at a plurality of points in a central region of the width
of the first surface is at least 1.1 times greater or 1.3 times
greater than an amount of the first catalytic material at one or
more points at the periphery of the width of the first surface.
[0090] In some embodiments, the amount of the first catalytic
material at point in a central region of the width of the first
surface is 1.3 times to 10 times greater than the amount of the
first catalytic material at a point at the periphery of the width
of the first surface. In some embodiments, the amount of the first
catalytic material at a plurality of points in a central region of
the width of the first surface is 1.3 times to 10 times greater
than the amount of the first catalytic material at one or more
points at the periphery of the width of the first surface.
[0091] In some embodiments of a section of an inner partition wall,
the average amount of the first catalytic material in a central
region of the width of the first surface of the inner partition
wall section is at least 1.5 times greater than the average amount
of the first catalytic material at the periphery of the width of
the first surface of the inner partition wall section.
[0092] In some embodiments, a central region of the width of the
first surface comprises up to about 20 percent of the total width
of the first surface, the central region centered around the
midpoint of the width of the first surface. In some embodiments, a
central region of the width of the first surface comprises up to
about 40 percent of the total width of the first surface, the
central region centered around the midpoint of the width of the
first surface.
[0093] In some embodiments, the periphery of the width of the first
surface comprises up to about 15 percent of the total width of the
first surface beginning at the edge of the width of the first
surface and extending in a direction toward the central region.
[0094] In some embodiments, a gradient of a first catalytic
material along the width of the first surface of the inner
partition wall has a profile symmetrical or substantially
symmetrical about the midpoint of the profile.
[0095] A structural catalyst body described herein, in some
embodiments, further comprises a gradient of the first catalytic
material along a width of the second surface. In some embodiments,
the first catalytic material of the gradient decreases in amount at
the periphery of the width of the second surface. The first
catalytic material of the gradient, in some embodiments, increases
in amount along a central region of the second surface.
[0096] In some embodiments, the amount of the first catalytic
material at a point in a central region of the width of the second
surface is at least 1.1 times greater or 1.3 times greater than the
amount of the first catalytic material at a point at the periphery
of the width of the second surface. In some embodiments, the amount
of the first catalytic material at a point in a central region of
the width of the second surface is at least 1.5 times or at least 2
times greater than the amount of the first catalytic material at a
point at the periphery of the width of the second surface. In some
embodiments, the amount of the first catalytic material at a point
in a central region of the width of the second surface is at least
3 times or at least 3.5 times greater than the amount of the first
catalytic material at a point at the periphery of the width of the
second surface. In some embodiments, the amount of the first
catalytic material at a point in a central region of the width of
the second surface is at least 4 times or at least 4.5 times
greater than the amount of the first catalytic material at a point
at the periphery of the width of the second surface.
[0097] In some embodiments, the amount of the first catalytic
material at a point in a central region of the width of the second
surface is at least 5 times or at least 10 times greater than the
amount of the first catalytic material at a point at the periphery
of the width of the second surface. In some embodiments, an amount
of the first catalytic material at a plurality of points in a
central region of the width of the second surface is at least 1.1
times greater or 1.3 times greater than the amount of the first
catalytic material at one or more points at the periphery of the
width of the second surface.
[0098] In some embodiments, the amount of the first catalytic
material at a point in a central region of the width of the second
surface is 1.3 times to 10 times greater than the amount of the
first catalytic material at a point at the periphery of the width
of the second surface. In some embodiments, the amount of the first
catalytic material at a plurality of points in a central region of
the width of the second surface is 1.3 times to 10 times greater
than the amount of the first catalytic material at one or more
points at the periphery of the width of the second surface.
[0099] In some embodiments of a section of an inner partition wall,
the average amount of the first catalytic material in a central
region of the width of the second surface of the inner partition
wall section is at least 1.5 times greater than the average amount
of the first catalytic material at the periphery of the width of
the second surface of the inner partition wall section.
[0100] In some embodiments, a central region of the width of the
second surface comprises up to about 20 percent of the total width
of the second surface, the central region centered around the
midpoint of the width of the second surface. In some embodiments, a
central region of the width of the second surface comprises up to
about 40 percent of the total width of the second surface, the
central region centered around the midpoint of the width of the
second surface.
[0101] In some embodiments, a periphery of the width of the second
surface comprises up to about 15 percent of the total width of the
second surface beginning at the edge of the width of the second
surface and extending in a direction toward the central region.
[0102] In some embodiments, a gradient of the first catalytic
material along the width of the second surface of the inner
partition wall has a profile symmetrical or substantially
symmetrical about the midpoint of the profile.
[0103] In some embodiments, a structural catalyst body described
herein further comprises a gradient of a second catalytic material
along the width of the first surface of the at least one inner
partition wall. In some embodiments, the second catalytic material
of the gradient decreases in amount at the periphery of the width
of the first surface.
[0104] In some embodiments, the second catalytic material of the
gradient increases in amount along a central region of the width of
the first surface. In some embodiments, the amount of the second
catalytic material in a central region of the width of the first
surface exceeds the amount of the second catalytic material at the
periphery of the width of the first surface. In some embodiments,
the amount of the second catalytic material at a point in a central
region of the width of the first surface is greater than the amount
of the second catalytic material at a point at the periphery of the
width of the first surface.
[0105] In some embodiments, the amount of the second catalytic
material at a point in a central region of the width of the first
surface is at least 1.1 times greater or 1.3 times greater than the
amount of the second catalytic material at a point at the periphery
of the width of the first surface. In some embodiments, the amount
of the second catalytic material at a point in a central region of
the width of the first surface is at least 1.5 times or at least 2
times greater than the amount of the second catalytic material at a
point at the periphery of the width of the first surface. In some
embodiments, the amount of the second catalytic material at a point
in a central region of the width of the first surface is at least 3
times or at least 3.5 times greater than the amount of the second
catalytic material at a point at the periphery of the width of the
first surface. In some embodiments, the amount of the second
catalytic material at a point in a central region of the width of
the first surface is at least 4 times or at least 4.5 times greater
than the amount of the second catalytic material at a point at the
periphery of the width of the first surface. In some embodiments,
the amount of the second catalytic material at a point in a central
region of the width of the first surface is at least 5 times or at
least 10 times greater than the amount of the second catalytic
material at a point at the periphery of the width of the first
surface. In some embodiments, an amount of the second catalytic
material at a plurality of points in a central region of the width
of the first surface is at least 1.1 times greater or 1.3 times
greater than an amount of the second catalytic material at one or
more points at the periphery of the width of the first surface.
[0106] In some embodiments, the amount of the second catalytic
material at point in a central region of the width of the first
surface is 1.3 times to 10 times greater than the amount of the
second catalytic material at a point at the periphery of the width
of the first surface. In some embodiments, the amount of the second
catalytic material at a plurality of points in a central region of
the width of the first surface is 1.3 times to 10 times greater
than the amount of the second catalytic material at one or more
points at the periphery of the width of the first surface.
[0107] In some embodiments, a gradient of a second catalytic
material along the width of the first surface of the inner
partition wall has a profile symmetrical or substantially
symmetrical about the midpoint of the profile.
[0108] In some embodiments of a section of an inner partition wall,
the average amount of the second catalytic material in a central
region of the width of the first surface of the inner partition
wall section is at least 1.5 times greater than the average amount
of the second catalytic material at the periphery of the width of
the first surface of the inner partition wall section.
[0109] A structural catalyst body described herein, in some
embodiments, further comprises a gradient of the second catalytic
material along a width of the second surface. In some embodiments,
the second catalytic material of the gradient decreases in amount
at the periphery of the width of the second surface. The second
catalytic material of the gradient, in some embodiments, increases
in amount along a central region of the second surface.
[0110] In some embodiments, the amount of the second catalytic
material at a point in a central region of the width of the second
surface is at least 1.1 times greater or 1.3 times greater than the
amount of the second catalytic material at a point at the periphery
of the width of the second surface. In some embodiments, the amount
of the second catalytic material at a point in a central region of
the width of the second surface is at least 1.5 times or at least 2
times greater than the amount of the second catalytic material at a
point at the periphery of the width of the second surface. In some
embodiments, the amount of the second catalytic material at a point
in a central region of the width of the second surface is at least
3 times or at least 3.5 times greater than the amount of the second
catalytic material at a point at the periphery of the width of the
second surface. In some embodiments, the amount of the second
catalytic material at a point in a central region of the width of
the second surface is at least 4 times or at least 4.5 times
greater than the amount of the second catalytic material at a point
at the periphery of the width of the second surface. In some
embodiments, the amount of the second catalytic material at a point
in a central region of the width of the second surface is at least
5 times or at least 10 times greater than the amount of the second
catalytic material at a point at the periphery of the width of the
second surface. In some embodiments, the amount of the second
catalytic material at a plurality of points in a central region of
the width of the second surface is at least 1.1 times greater or
1.3 times greater than the amount of the second catalytic material
at one or more points at the periphery of the width of the second
surface.
[0111] In some embodiments, the amount of the second catalytic
material at a point in a central region of the width of the second
surface is 1.3 times to 10 times greater than the amount of the
second catalytic material at a point at the periphery of the width
of the second surface. In some embodiments, the amount of the
second catalytic material at a plurality of points in a central
region of the width of the second surface is 1.3 times to 10 times
greater than the amount of the second catalytic material at one or
more points at the periphery of the width of the second
surface.
[0112] In some embodiments of a section of an inner partition wall,
the average amount of the second catalytic material in a central
region of the width of the second surface of the inner partition
wall section is at least 1.5 times greater than the average amount
of the second catalytic material at the periphery of the width of
the second surface of the inner partition wall section.
[0113] In some embodiments, a gradient of the first catalytic
material along the width of the second surface of the inner
partition wall has a profile symmetrical or substantially
symmetrical about the midpoint of the profile.
[0114] FIG. 1 illustrates gradient profiles of first and second
catalytic materials along the width of the surface of an inner
partition wall of a structural catalyst body according to one
embodiment described herein. As illustrated in FIG. 1, the first
catalytic material of vanadium pentoxide (V.sub.2O.sub.5) and the
second catalytic material of tungsten oxide (WO.sub.3) increase in
amount along a central region of the width of the inner partition
wall surface. Moreover, the V.sub.2O.sub.5 first catalytic material
and the WO.sub.3 second catalytic material decrease in amount at
the periphery of the width of the inner partition wall surface. The
profiles of the V.sub.2O.sub.5 first catalytic material and the
WO.sub.3 second catalytic material are also substantially
symmetrical about the midpoints of the profiles.
[0115] In some embodiments, a structural catalyst body described
herein comprises a gradient of bulk first catalytic material along
the width of at least one inner partition wall. In some
embodiments, bulk first catalytic material of the gradient
decreases in concentration at the periphery of the width of the
inner partition wall. In some embodiments, bulk first catalytic
material increases in concentration along a central region of the
width of the inner partition wall. In some embodiments, a gradient
of bulk first catalytic material along the width of the inner
partition wall has a profile symmetrical or substantially
symmetrical about the midpoint of the profile.
[0116] In some embodiments, the concentration of bulk first
catalytic material at a point in a central region of the width of
the inner partition wall is at least 1.1 times greater or 1.3 times
greater than the concentration of bulk first catalytic material at
a point at the periphery of the width of the inner partition wall.
In some embodiments, the concentration of bulk first catalytic
material at a point in a central region of the width of the inner
partition wall is at least 1.5 times or at least 2 times greater
than the concentration of bulk first catalytic material at a point
at the periphery of the width of the inner partition wall. In some
embodiments, the concentration of bulk first catalytic material at
a point in a central region of the width of the inner partition
wall is at least 3 times or at least 3.5 times greater than the
concentration of bulk first catalytic material at a point at the
periphery of the width of the inner partition wall. In some
embodiments, the concentration of bulk first catalytic material at
a point in a central region of the width of the inner partition
wall is at least 4 times or at least 4.5 times greater than the
concentration of bulk first catalytic material at a point at the
periphery of the width of the inner partition wall. In some
embodiments, the concentration of bulk first catalytic material at
a point in a central region of the width of the inner partition
wall is at least 5 times or at least 10 times greater than the
concentration of bulk first catalytic material at a point at the
periphery of the width of the inner partition wall. In some
embodiments, the concentration of bulk first catalytic material at
a plurality of points in a central region of the width of the inner
partition wall is at least 1.1 times greater or 1.3 times greater
than the concentration of bulk first catalytic material at one or
more points at the periphery of the width of the inner partition
wall.
[0117] In some embodiments, the concentration of bulk first
catalytic material at a point in a central region of the width of
the inner partition wall is 1.3 times to 10 times greater than the
concentration of bulk first catalytic material at a point at the
periphery of the width of the inner partition wall. In some
embodiments, a concentration of bulk first catalytic material at a
plurality of points in the central region of the width of the inner
partition wall is 1.3 times to 10 times greater than the
concentration of bulk first catalytic material at one or more
points at the periphery of the width of the inner partition
wall.
[0118] In some embodiments, a central region of the width of the
inner partition wall comprises up to about 20 percent of the total
width of the inner partition wall, the central region centered
around the midpoint of the width of the inner partition wall. In
some embodiments, a central region of the width of the inner
partition wall comprises up to about 40 percent of the total width
of the inner partition wall, the central region centered around the
midpoint of the width of the inner partition wall.
[0119] In some embodiments, a periphery of the width of the inner
partition wall comprises up to about 15 percent of the total width
of the inner partition wall beginning at the edge of the width of
the inner partition wall and extending in a direction toward the
central region.
[0120] In some embodiments, a structural catalyst body described
herein further comprises a gradient of bulk second catalytic
material along the width of the at least one inner partition wall
comprising the gradient of bulk first catalytic material.
[0121] In some embodiments, bulk second catalytic material of the
gradient decreases in concentration at the periphery of the width
of the inner partition wall. In some embodiments, bulk second
catalytic material increases in concentration along a central
region of the width of the inner partition wall. In some
embodiments, a gradient of bulk second catalytic material along the
width of the inner partition wall has a profile symmetrical or
substantially symmetrical about the midpoint of the profile.
[0122] In some embodiments, the concentration of bulk second
catalytic material at a point in a central region of the width of
the inner partition wall is at least 1.1 times greater or 1.3 times
greater than the concentration of bulk second catalytic material at
a point at the periphery of the width of the inner partition wall.
In some embodiments, the concentration of bulk second catalytic
material at a point in a central region of the width of the inner
partition wall is at least 1.5 times or at least 2 times greater
than the concentration of bulk second catalytic material at a point
at the periphery of the width of the inner partition wall. In some
embodiments, the concentration of bulk second catalytic material at
a point in a central region of the width of the inner partition
wall is at least 3 times or at least 3.5 times greater than the
concentration of bulk second catalytic material at a point at the
periphery of the width of the inner partition wall. In some
embodiments, the concentration of bulk second catalytic material at
a point in a central region of the width of the inner partition
wall is at least 4 times or at least 4.5 times greater than the
concentration of bulk second catalytic material at a point at the
periphery of the width of the inner partition wall. In some
embodiments, the concentration of bulk second catalytic material at
a point in a central region of the width of the inner partition
wall is at least 5 times or at least 10 times greater than the
concentration of bulk second catalytic material at a point at the
periphery of the width of the inner partition wall. In some
embodiments, the concentration of bulk second catalytic material at
a plurality of points in a central region of the width of the inner
partition wall is at least 1.1 times greater or 1.3 times greater
than the concentration of bulk second catalytic material at one or
more points at the periphery of the width of the inner partition
wall.
[0123] In some embodiments, the concentration of bulk second
catalytic material at a point in a central region of the width of
the inner partition wall is 1.3 times to 10 times greater than the
concentration of bulk second catalytic material at a point at the
periphery of the width of the inner partition wall. In some
embodiments, the concentration of bulk second catalytic material at
a plurality of points in the central region of the width of the
inner partition wall is 1.3 times to 10 times greater than the
concentration of bulk second catalytic material at one or more
points at the periphery of the width of the inner partition
wall.
[0124] In some embodiments, a structural catalyst body described
herein further comprises a gradient of first catalytic material
along a length of the first surface of the inner partition wall. A
gradient of first catalytic material along the length of the first
surface of the inner partition wall, in some embodiments, comprises
a greater amount of first catalytic material at a first end of the
inner partition wall in comparison with an amount of the first
catalytic material at a second end of the inner partition wall, the
second end opposite the first end. In some embodiments, the amount
of first catalytic material at a point on the first surface at the
first end of the inner partition wall is 1.3 times to 10 times
greater than the amount of the first catalytic material at a point
on the first surface at the second end of the inner partition wall.
In some embodiments, the amount of first catalytic material at a
point on the first surface at the first end of the inner partition
wall is at least 10 times greater than the amount of first
catalytic material at a point on the first surface at the second
end of the inner partition wall.
[0125] In some embodiments, a structural catalyst body described
herein further comprises a gradient of second catalytic material
along a length of the first surface of the inner partition wall. A
gradient of second catalytic material along the length of the first
surface of the inner partition wall, in some embodiments, comprises
a greater amount of second catalytic material at a first end of the
inner partition wall in comparison with an amount of the second
catalytic material at a second end of the inner partition wall, the
second end opposite the first end. In some embodiments, the amount
of second catalytic material at a point on the first surface at the
first end of the inner partition wall is 1.3 times to 10 times
greater than the amount of the second catalytic material at a point
on the first surface at the second end of the inner partition wall.
In some embodiments, the amount of second catalytic material at a
point on the first surface at the first end of the inner partition
wall is at least 10 times greater than the amount of second
catalytic material at a point on the first surface at the second
end of the inner partition wall.
[0126] In some embodiments, a structural catalyst body described
herein further comprises a gradient of first catalytic material
along a length of the second surface of the inner partition wall. A
gradient of first catalytic material along the length of the second
surface of the inner partition wall, in some embodiments, comprises
a greater amount of the first catalytic material at a first end of
the inner partition wall in comparison with an amount of the first
catalytic material at a second end of the inner partition wall, the
second end opposite the first end. In some embodiments, the amount
of the first catalytic material at a point on the second surface at
the first end of the inner partition wall is 1.3 times to 10 times
greater than the amount of the first catalytic material at a point
on the second surface at the second end of the inner partition
wall. In some embodiments, the amount of the first catalytic
material at a point on the second surface at the second end of the
inner partition wall is at least 10 times greater than the amount
of the first catalytic material at a point on the second surface at
the second end of the inner partition wall.
[0127] In some embodiments, the gradient of the first catalytic
material along the length of the second surface of the inner
partition wall is symmetrical or substantially symmetrical to the
gradient of the first catalytic material along the length of the
first surface of the inner partition wall.
[0128] In some embodiments, the first end of the inner partition
wall corresponds to the fluid stream inlet side of the structural
catalyst body and the second end corresponds to the fluid stream
outlet side of the structural catalyst body.
[0129] In some embodiments, a structural catalyst body described
herein further comprises a gradient of second catalytic material
along a length of the second surface of the inner partition wall. A
gradient of second catalytic material along the length of the
second surface of the inner partition wall, in some embodiments,
comprises a greater amount of the second catalytic material at a
first end of the inner partition wall in comparison with an amount
of the second catalytic material at a second end of the inner
partition wall, the second end opposite the first end. In some
embodiments, the amount of the second catalytic material at a point
on the second surface at the first end of the inner partition wall
is 1.3 times to 10 times greater than the amount of the second
catalytic material at a point on the second surface at the second
end of the inner partition wall. In some embodiments, the amount of
the second catalytic material at a point on the second surface at
the second end of the inner partition wall is at least 10 times
greater than the amount of the second catalytic material at a point
on the second surface at the second end of the inner partition
wall.
[0130] In some embodiments, the gradient of the second catalytic
material along the length of the second surface of the inner
partition wall is symmetrical or substantially symmetrical to the
gradient of the second catalytic material along the length of the
first surface of the inner partition wall.
[0131] In some embodiments, a structural catalyst body described
herein comprises a gradient of bulk first catalytic material along
a length of at least one inner partition wall. In some embodiments,
a gradient of bulk first catalytic material along a length of the
inner partition wall comprises a greater concentration of bulk
first catalytic material at a first end of the inner partition wall
in comparison with a concentration of bulk first catalytic material
at a second end of the inner partition wall, the second end
opposite the first end. As described herein, in some embodiments,
the first end of the inner partition wall corresponds to the fluid
stream inlet side of the structural catalyst body and the second
end corresponds to the fluid stream outlet side of the structural
catalyst body.
[0132] In some embodiments, the concentration of bulk first
catalytic material at a point at the first end of the inner
partition wall is 1.3 times to 10 times greater than the
concentration of bulk first catalytic material at a point at the
second end of the inner partition wall. In some embodiments, the
concentration of bulk first catalytic material at a point at the
first end of the inner partition wall is at least 10 times greater
than the concentration of bulk first catalytic material at a point
at the second end of the inner partition wall.
[0133] In some embodiments, a structural catalyst body described
herein further comprises a gradient of bulk second first catalytic
material along a length of at least one inner partition wall. In
some embodiments, a gradient of a bulk second catalytic material
along a length of the inner partition wall comprises a greater
concentration of bulk second catalytic material at a first end of
the inner partition wall in comparison with a concentration of bulk
second catalytic material at a second end of the inner partition
wall, the second end opposite the first end.
[0134] In some embodiments, the concentration of bulk second
catalytic material at a point at the first end of the inner
partition wall is 1.3 times to 10 times greater than the
concentration of bulk second catalytic material at a point at the
second end of the inner partition wall. In some embodiments, the
concentration of bulk second catalytic material at a point at the
first end of the inner partition wall is at least 10 times greater
than the concentration of bulk second catalytic material at a point
at the second end of the inner partition wall.
[0135] A structural catalyst body described herein, in some
embodiments, further comprises at least one additional inner
partition wall comprising one or more gradients of first catalytic
material and/or second catalytic material described herein for an
inner partition wall. In some embodiments, the at least one
additional inner partition wall comprises a first surface and a
second surface and a gradient of first catalytic material and/or
second catalytic material along a width of the first surface. In
some embodiments, the at least one additional inner partition wall
further comprises a gradient of first catalytic material and/or
second catalytic material along a width of the second surface. A
gradient of first catalytic material and/or second catalytic
material along the width of the first surface and/or the second
surface of the at least one additional inner partition wall, in
some embodiments, has one or more properties consistent with the
same described for the inner partition wall hereinabove.
[0136] Moreover, in some embodiments, the at least one additional
inner partition wall comprises a gradient of bulk first catalytic
material and/or bulk second catalytic material along a width of the
additional inner partition wall. In some embodiments, the at least
one additional inner partition wall comprises a gradient of bulk
first catalytic material and/or second catalytic material along a
length of the inner partition wall.
[0137] The at least one additional inner partition wall, in some
embodiments, comprises a gradient of first catalytic material
and/or second catalytic material along the length of the first
surface and/or second surface. A gradient of the first catalytic
material and/or second catalytic material along the length of the
first surface and/or the second surface of the at least one
additional inner partition wall, in some embodiments, has one or
more properties consistent with the same described for the inner
partition wall hereinabove.
[0138] In some embodiments, the at least one additional inner
partition wall comprises a plurality of additional inner partition
walls such that greater than about 50 percent or greater than about
70 percent of the inner partition walls of the structural catalyst
body comprise one or more gradients of catalytic material described
herein. In some embodiments, greater than about 90 percent of the
inner partition walls of the structural catalyst body comprise one
or more gradients of catalytic material described herein. In some
embodiments, greater than about 95 percent of the inner partition
walls of the structural catalyst body comprise one or more
gradients of catalytic material described herein.
[0139] FIG. 2 illustrates a honeycomb-like structural catalyst body
according to one embodiment described herein. The structural
catalyst body of FIG. 2 comprises an outer peripheral wall (10) and
a plurality of inner partition walls (11), wherein one or more of
the inner partition walls (11) have one or more gradients of first
and/or second catalytic material as described herein. The inner
partition walls (11) define a plurality of flow channels or cells
(12) which extend longitudinally through the honeycomb-like
structural catalyst body.
[0140] FIG. 3 illustrates a cross-section of a portion of a
honeycomb-like structural catalyst body according to one embodiment
described herein. The flow channels (12) of the structural catalyst
body are defined by the inner partition walls (11). The inner
partition walls (11) and their junctures with the outer peripheral
wall (10) serve as boundaries of adjacent, flow channels (12). An
inner partition wall (11) comprises a first surface (14), a second
surface (15) and a cross-sectional region (16) bridging the first
surface (14) and the second surface (15). The first surface (14)
and/or the second surface (15) have a gradient of first catalytic
material and/or second catalytic material along the width of the
first surface and/or the second surface as described herein. The
width of an inner partition wall surface in the embodiment of FIG.
3 is illustrated as (18). As the cross-sectional profile of flow
channels (12) of the honeycomb-like structural catalyst body
illustrated in FIG. 3 is square, the inner partition walls (11)
have equal or substantially equal widths (18).
[0141] In some embodiments, cross-sectional profiles of flow
channels can be nominally polygonal such as triangular, square,
rectangular or hexagonal. In some embodiments, cross-sectional
profiles of flow channels can be round or oval or combinations with
polygonal and curved shapes such as annular sectors. Moreover, in
some embodiments, the cross-sectional profile of the outer
perimeter of the outer peripheral wall of the catalytic body can be
square, rectangular, round, oval, circular sectors such as pie
slices or quadrants, or any other geometric shape or shapes
convenient for a given application.
[0142] FIG. 6 illustrates a cross-section of a portion of a
corrugated structural catalyst body according to one embodiment
described herein. The flow channels (61) of the structural catalyst
body (60) are defined by inner partition walls (62, 63). The inner
partition walls (62, 63) and their junctures or intersections with
one another serve as boundaries for adjacent flow channels (61). As
illustrated in FIG. 6, the corrugated catalyst body (60) comprises
flat inner partition walls (63) having a width as defined by the
distance between A and C. The corrugated catalyst body also has
curved inner partition walls (62) having a width defined by the
distance between A and B. Inner partition walls (62, 63) comprise a
first surface (64) and a second surface (65). The first surface
(64) and/or the second surface (65) have a gradient of first
catalytic material and/or second catalytic material along the width
of the first surface and/or second surface as described herein.
Moreover, intersection of inner partition walls (62) with one
another at points A, B and C, for example, provide centerpost
structures (66).
[0143] In some embodiments wherein the outer peripheral wall
comprises a bulk first catalytic material, inner partition walls of
a structural catalyst body comprise more bulk first catalytic
material than the outer peripheral wall. In some embodiments, for
example, the concentration of bulk first catalytic material at a
point in an inner partition wall is about 1.1 to about 10 times
greater than the concentration of bulk first catalytic material at
a point in an outer peripheral wall.
[0144] In some embodiments wherein the outer peripheral wall
further comprises a bulk second catalytic material, inner partition
walls of a structural catalyst body comprise more bulk second
catalytic material than the outer peripheral wall. In some
embodiments, for example, the concentration of bulk second
catalytic material at a point in an inner partition wall is about
1.1 to about 10 times greater than the concentration of bulk second
catalytic material at a point in an outer peripheral wall.
[0145] In some embodiments, a structural catalyst body described
herein comprises a containment structure in which the inner
partition walls are disposed, such as in the arrangement of plate
catalyst elements or corrugated catalyst elements in the
containment structure.
[0146] As illustrated in FIG. 3, the intersection of inner
partition walls (11) of the honeycomb form centerpost structures
(17). In some embodiments, intersection of spacer structures and/or
walls of plate catalyst elements of a structural catalyst body
described herein form centerpost structures. In some embodiments,
intersection walls of corrugated catalyst elements of a structural
catalyst body described herein form centerpost structures.
[0147] A structural catalyst body, in some embodiments, further
comprises a gradient of bulk first catalytic material between a
centerpost and least one inner partition wall connected to the
centerpost. In some embodiments, for example, the at least one
inner partition wall comprises a greater concentration of a bulk
first catalytic material than the centerpost. In some embodiments,
a structural catalyst body described herein comprises a gradient of
bulk first catalytic material between a centerpost and a plurality
of inner partition walls connected to the centerpost. In some
embodiments, each of the inner partition walls connected to the
centerpost comprises a greater concentration of a bulk first
catalytic material than the centerpost.
[0148] In some embodiments, the concentration of bulk first
catalytic material at a point in an inner partition wall is at
least 1.1 times greater or 1.3 times greater than the concentration
of bulk first catalytic material at a point in the centerpost. In
some embodiments, the concentration of bulk first catalytic
material at a point in an inner partition wall is at least 1.5
times or at least 2 times greater than the concentration of bulk
first catalytic material at a point in the centerpost. In some
embodiments, the concentration of bulk first catalytic material at
a point in an inner partition wall is at least 3 times or at least
3.5 times greater than the concentration of bulk first catalytic
material at a point in the centerpost. In some embodiments, the
concentration of bulk first catalytic material at a point in an
inner partition wall is at least 4 times or at least 4.5 times
greater than the concentration of bulk first catalytic material at
a point in the centerpost. In some embodiments, the concentration
of bulk first catalytic material at a point in an inner partition
wall is at least 5 times or at least 10 times greater than the
concentration of bulk first catalytic material at a point in the
centerpost. In some embodiments, a concentration of bulk first
catalytic material at a plurality of points in an inner partition
wall is at least 1.1 times greater or 1.3 times greater than the
concentration of bulk first catalytic material at one or more
points in the centerpost.
[0149] In some embodiments, the concentration of bulk first
catalytic material at a point in an inner partition wall is 1.3
times to 10 times greater than the concentration of bulk first
catalytic material at a point in the centerpost. In some
embodiments, a concentration of bulk first catalytic material at a
plurality of points in an inner partition wall is 1.3 times to 10
times greater than the concentration of bulk first catalytic
material at one or more points in the centerpost.
[0150] A structural catalyst body, in some embodiments, further
comprises a gradient of bulk second catalytic material between a
centerpost and least one inner partition wall connected to the
centerpost. In some embodiments, for example, the at least one
inner partition wall comprises a greater concentration of a bulk
second catalytic material than the centerpost. In some embodiments,
a structural catalyst body described herein comprises a gradient of
bulk second catalytic material between a centerpost and a plurality
of inner partition walls connected to the centerpost. In some
embodiments, each of the inner partition walls connected to the
centerpost comprises a greater concentration of a bulk second
catalytic material than the centerpost.
[0151] In some embodiments, the concentration of bulk second
catalytic material at a point in an inner partition wall is at
least 1.1 times greater or 1.3 times greater than the concentration
of bulk second catalytic material at a point in the centerpost. In
some embodiments, the concentration of bulk second catalytic
material at a point in an inner partition wall is at least 1.5
times or at least 2 times greater than the concentration of bulk
second catalytic material at a point in the centerpost. In some
embodiments, the concentration of bulk second catalytic material at
a point in an inner partition wall is at least 3 times or at least
3.5 times greater than the concentration of bulk second catalytic
material at a point in the centerpost. In some embodiments, the
concentration of bulk second catalytic material at a point in an
inner partition wall is at least 4 times or at least 4.5 times
greater than the concentration of bulk second catalytic material at
a point in the centerpost. In some embodiments, the concentration
of bulk second catalytic material at a point in an inner partition
wall is at least 5 times or at least 10 times greater than the
concentration of bulk second catalytic material at a point in the
centerpost. In some embodiments, a concentration of bulk second
catalytic material at a plurality of points in an inner partition
wall is at least 1.1 times greater or 1.3 times greater than the
concentration of bulk second catalytic material at one or more
points in the centerpost.
[0152] In some embodiments, the concentration of bulk second
catalytic material at a point in an inner partition wall is 1.3
times to 10 times greater than the concentration of bulk second
catalytic material at a point in the centerpost. In some
embodiments, a concentration of bulk second catalytic material at a
plurality of points in an inner partition wall is 1.3 times to 10
times greater than the concentration of bulk second catalytic
material at one or more points in the centerpost.
[0153] Embodiments described herein contemplate structural catalyst
bodies having any combination of the foregoing gradients of first
catalytic material and/or second catalytic material. In some
embodiments, for example, a structural catalyst described herein
can have any combination of gradients of first catalytic material
and/or second catalytic material as provided in Table I of FIG.
5.
[0154] In some embodiments, the outer peripheral wall and the inner
partition walls of a structural catalyst body described herein are
formed from a support material such as an inorganic oxide
composition, including refractory metal oxide compositions. The
inorganic oxide composition, in some embodiments, comprises titania
(TiO.sub.2), alumina (Al.sub.2O.sub.3), zirconia (ZrO.sub.2),
silica (SiO.sub.2), silicate or mixtures thereof. In some
embodiments, the chemical composition comprises an inorganic oxide
composition of TiO.sub.2, Al.sub.2O.sub.3, ZrO.sub.2 or SiO.sub.2
or mixtures thereof in an amount ranging from about 70 weight
percent to 100 weight percent. In some embodiments, the inorganic
oxide composition is sintered or otherwise heat treated to increase
the mechanical integrity of the structural catalyst body.
[0155] In some embodiments, an outer peripheral wall and the inner
partition walls of a structural catalyst body described herein are
formed from a composition comprising catalytic material. In some
embodiments, the outer peripheral wall and the inner partition
walls of a structural catalyst body are formed of a chemical
composition comprising 50-99.99% by weight an inorganic oxide
composition and at least 0.01% by weight a catalytically active
metal functional group. In some embodiments, the catalytically
active metal functional group can comprise any of the catalytic
materials described herein. In some embodiments, structural
catalyst bodies comprising an outer peripheral wall and inner
partition walls formed from a composition comprising catalytic
material are described in U.S. Pat. Nos. 7,807,110, 7,776,786 and
7,658,898 which are hereby incorporated by reference in their
entireties. In some embodiments, the catalytically active metal
functional group is dispersed throughout the chemical composition.
In some embodiments, the catalytically active metal functional
group is dispersed uniformly or substantially uniformly throughout
the chemical composition.
[0156] In some embodiments, structural catalyst bodies described
herein comprise virgin structural catalyst bodies. A virgin
structural catalyst body, in some embodiments, has not been used or
previously installed into a catalytic reactor for conducting
catalytic reactions in a fluid stream.
[0157] In some embodiments, a structural catalyst body described is
used or regenerated. A used structural catalyst body, in some
embodiments, has been previously installed in a catalytic reactor
for conducting catalytic reactions in a fluid stream.
[0158] In some embodiments, catalytic material of gradients of
structural catalyst bodies described herein comprise one or more
transition metals. In some embodiments, transition metals of
catalytic material comprise vanadium, tungsten, molybdenum,
platinum, palladium, ruthenium, rhodium, rhenium, iron, gold,
silver, copper or nickel or alloys or oxides thereof. In some
embodiments, one or more catalytic materials of gradients of
structural catalyst bodies described herein are suitable for SCR
applications and processes. In some embodiments, for example,
catalytic material comprises V.sub.2O.sub.5, WO.sub.3 or MoO.sub.3
or mixtures thereof.
[0159] In some embodiments, the first catalytic material described
herein comprises a transition metal selected from the group
consisting of vanadium, tungsten, molybdenum, platinum, palladium,
ruthenium, rhodium, rhenium, iron, gold, silver, copper and nickel
and alloys and oxides thereof. In some embodiments, for example,
the first catalytic material is V.sub.2O.sub.5, WO.sub.3 or
MoO.sub.3. Moreover, in some embodiments, the second catalytic
material described herein comprises a transition metal selected
from the group consisting of vanadium, tungsten, molybdenum,
platinum, palladium, ruthenium, rhodium, rhenium, iron, gold,
silver, copper and nickel and alloys and oxides thereof. In some
embodiments, for example, the second catalytic material is
V.sub.2O.sub.5, WO.sub.3 or MoO.sub.3. In some embodiments, the at
least one additional catalytic material described herein comprises
a transition metal selected from the group consisting of vanadium,
tungsten, molybdenum, platinum, palladium, ruthenium, rhodium,
rhenium, iron, gold, silver, copper and nickel and alloys and
oxides thereof. In some embodiments, for example, the at least one
additional catalytic material is V.sub.2O.sub.5, WO.sub.3 or
MoO.sub.3.
[0160] Structural catalyst bodies described herein can have any
dimensions and mechanical properties not inconsistent with the
objectives of the present invention. In some embodiments,
structural catalyst bodies have dimensions and mechanical
properties suitable for use in SCR applications and processes. In
some embodiments, for example, structural catalyst bodies can have
one or more properties consistent with a structural catalyst body
described in U.S. Pat. Nos. 7,807,110, 7,776,786 and 7,658,898. In
some embodiments, structural catalyst bodies described herein
comprise plate catalyst bodies or corrugated catalyst bodies. In
some embodiments, a structural catalyst body described herein can
comprise one or more plate catalyst element or corrugated catalyst
elements.
[0161] In another aspect, a catalyst module is described herein
comprising a framework and a plurality of structural catalyst
bodies disposed in the framework, the structural catalyst bodies
comprising a gradient of first catalytic material along a width of
a surface of at least one inner partition wall as described herein,
wherein the catalytic activity of the catalyst bodies of the module
is substantially uniform. In being substantially uniform, catalytic
activity between catalyst bodies of the module, in some
embodiments, varies less than about 20%. In some embodiments, in
being substantially uniform, catalytic activity between catalyst
bodies of the module varies less than 10%. In some embodiments, in
being substantially uniform, catalytic activity between catalyst
bodies of the module varies less than 5%. In some embodiments,
catalytic activity comprises the selective catalytic reduction of
nitrogen oxides, the oxidation of mercury or the oxidation of
ammonia or combinations thereof.
[0162] In some embodiments, sulfur dioxide oxidation activity of
catalyst bodies of the module is substantially uniform. In being
substantially uniform, sulfur dioxide oxidation activity between
catalyst bodies of the module, in some embodiments, varies less
than 40%. In some embodiments, in being substantially uniform,
sulfur dioxide oxidation activity between catalyst bodies of the
module varies less than 20%. In some embodiments, in being
substantially uniform, sulfur dioxide oxidation activity between
catalyst bodies of the module varies less than 10%.
[0163] Moreover, in some embodiments, catalyst bodies of a module
comprise one or more catalytic gradients described herein in
addition to a gradient of a first catalytic material along the
width of a surface of at least one inner partition wall. In some
embodiments, for example, catalyst bodies of the module also
comprise a gradient of bulk first catalytic material along a width
and/or length of at least one inner partition as described herein.
In some embodiments, catalyst bodies of a module can have any
combination of the gradients provided in Table I of FIG. 5.
[0164] In another aspect, at least one catalyst layer of a
catalytic reactor is described herein, the catalyst layer
comprising a plurality of structural catalyst bodies, the
structural catalyst bodies comprising a gradient of first catalytic
material along a width of a surface of at least one inner partition
wall as described herein, wherein the catalytic activity of the
structural catalyst bodies of the catalyst layer is substantially
uniform. In being substantially uniform, in some embodiments,
catalytic activity between catalyst bodies of the catalyst layer
varies less than about 20%. In some embodiments, in being
substantially uniform, catalytic activity between catalyst bodies
of the catalyst layer varies less than about 10%. In some
embodiments, in being substantially uniform, catalytic activity
between catalyst bodies of the catalyst layer varies less than
about 5%. In some embodiments, catalytic activity comprises the
selective catalytic reduction of nitrogen oxides, the oxidation of
mercury or the oxidation of ammonia or combinations thereof.
[0165] In some embodiments, sulfur dioxide oxidation activity of
catalyst bodies of the catalyst layer is substantially uniform. In
being substantially uniform, sulfur dioxide oxidation activity
between catalyst bodies of the catalyst layer, in some embodiments,
varies less than 40%. In some embodiments, in being substantially
uniform, sulfur dioxide oxidation activity between catalyst bodies
of the catalyst layer varies less than 20%. In some embodiments, in
being substantially uniform, sulfur dioxide oxidation activity
between catalyst bodies of the catalyst layer varies less than
10%.
[0166] In some embodiments, catalyst bodies of a catalyst layer
comprise one or more catalytic gradients described herein in
addition to the gradient of first catalytic material along the
width of a surface of at least one inner partition wall. In some
embodiments, for example, catalyst bodies of a catalyst layer also
comprise a gradient of bulk first catalytic material along a width
and/or length of at least one inner partition as described herein.
In some embodiments, catalyst bodies of a catalyst layer can have
any combination of the gradients provided in Table I of FIG. 5.
[0167] In some embodiments, catalyst bodies of a catalyst layer are
arranged into one or more modules.
[0168] In another aspect, methods of producing structural catalyst
bodies described herein are provided. In some embodiments, a method
of producing a structural catalyst body comprises providing a
catalyst support comprising at least one inner partition wall
comprising a first surface and a second surface opposite the first
surface, impregnating the at least one inner partition wall with a
solution comprising a first catalytic material and drying the at
least one inner partition wall in a manner to establish a gradient
of the first catalytic material along a width of the first surface.
In some embodiments, the first catalytic material of the gradient
decreases in amount at the periphery of the width of the first
surface. In some embodiments, the first catalytic material of the
gradient increases in amount along a central region of the width of
the first surface.
[0169] In some embodiments, a gradient of the first catalytic
material is also established along a width of the second surface.
In some embodiments, the first catalytic material of the gradient
decreases in amount at the periphery of the width of the second
surface. The first catalytic material of the gradient, in some
embodiments, increases in amount along a central region of the
width of the second surface. In some embodiments, the gradient
profile of the first catalytic material along the width of the
second surface is symmetrical or substantially symmetrical to the
gradient profile of the first catalytic material along the width of
the first surface.
[0170] In some embodiments, the at least one inner partition wall
of the structural catalyst support is dried in a manner to
establish a gradient of bulk first catalytic material along a width
of the inner partition wall. In some embodiments, bulk first
catalytic material of the gradient decreases in concentration at
the periphery of the width of the inner partition wall. In some
embodiments, bulk first catalytic material increases in
concentration along a central region of the width of the inner
partition wall. In some embodiments, a gradient of a bulk first
catalytic material along the width of the inner partition wall has
a profile symmetrical or substantially symmetrical about the
midpoint of the profile.
[0171] In some embodiments, the at least one inner partition wall
of the structural catalyst support is dried in a manner to
establish a gradient of the first catalyst material along a length
of the first surface of the inner partition wall. A gradient of the
first catalytic material along the length of a first surface of the
inner partition wall, in some embodiments, comprises a greater
amount of the first catalytic material at a first end of the inner
partition wall in comparison with an amount of the first catalytic
material at a second end of the inner partition wall, the second
end opposite the first end.
[0172] In some embodiments, a gradient of the first catalytic
material is also established along a length of the second surface
of the inner partition wall. A gradient of the first catalytic
material along the length of the second surface of the inner
partition wall, in some embodiments, comprises a greater amount of
the first catalytic material at a first end of the inner partition
wall in comparison with an amount of the first catalytic material
at a second end of the inner partition wall, the second end
opposite the first end. In some embodiments, the gradient profile
of the first catalytic material along the length of the second
surface of the inner partition wall is symmetrical or substantially
symmetrical to the gradient profile of the first catalytic material
along the length of the first surface of the inner partition
wall.
[0173] In some embodiments, the first end of the inner partition
wall corresponds to the fluid stream inlet side of the structural
catalyst body and the second end corresponds to the fluid stream
outlet side of the structural catalyst body. Alternatively, in some
embodiments, the first end of the inner partition wall corresponds
to the outlet side of the structural catalyst body, and the second
end corresponds to the fluid stream inlet side.
[0174] In some embodiments, the at least one inner partition wall
of a structural catalyst body described herein is dried in a manner
to establish a gradient of a bulk first catalytic material along a
length of the inner partition wall. In some embodiments, a gradient
of a first bulk catalytic material along a length of the inner
partition wall comprises a greater concentration of the bulk first
catalytic material at a first end of the inner partition wall in
comparison with a concentration of the bulk first catalytic
material at a second end of the inner partition wall, the second
end opposite the first end.
[0175] In some embodiments of methods described herein, the
structural catalyst body comprises a plurality of inner partition
walls such that the inner partition walls are impregnated with a
solution comprising the first catalytic material and dried in a
manner to establish a gradient of the of the first catalytic
material along a width and/or length of one or more surfaces of the
inner partition walls. In some embodiments, the inner partition
walls are dried in a manner to establish a gradient of a bulk first
catalytic material along a width and/or length of the inner
partition walls.
[0176] In some embodiments, inner partition walls of a structural
catalyst body produced according to methods described herein
intersect to form one or more centerposts. In some embodiments, at
least one centerpost is impregnated with a solution comprising the
first catalytic material and dried in a manner to establish a
gradient of bulk first catalytic material between the centerpost
and at least one of the inner partition walls. In some embodiments,
for example, at least one inner partition wall comprises a greater
concentration of bulk first catalytic material than the centerpost.
In some embodiments, each of the inner partition walls connected to
the centerpost comprises a greater concentration of bulk first
catalytic material than the centerpost.
[0177] In some embodiments of methods described herein, the
impregnating solution further comprises a second catalytic
material. In some embodiments, a gradient of bulk metal or metal
oxide second catalytic material is established along a width of the
inner partition wall. Alternatively, in some embodiments, at least
one inner partition wall of a structural catalyst body comprising
one or more gradients of the first catalytic material described
herein is further impregnated with a solution comprising a metal or
metal oxide second catalytic material and dried in a manner to
establish a gradient of the metal or metal oxide second catalytic
material along a width of the first surface and/or second surface
of the inner partition wall. In some embodiments, a gradient of
bulk metal or metal oxide second catalytic material is established
along a width of the inner partition wall.
[0178] In some embodiments, the second catalytic material of the
gradient decreases in amount at the periphery of the width of the
first surface. In some embodiments, the second catalytic material
of the gradient increases in amount along a central region of the
width of the first surface.
[0179] In some embodiments, a gradient of the second catalytic
material is also established along a width of the second surface of
the inner partition wall. In some embodiments, the second catalytic
material of the gradient decreases in amount at the periphery of
the width of the second surface. The second catalytic material of
the gradient, in some embodiments, increases in amount along a
central region of the width of the second surface. In some
embodiments, the gradient profile of the second catalytic material
along the width of the second surface is symmetrical or
substantially symmetrical to the gradient profile of the second
catalytic material along the width of the first surface.
[0180] In some embodiments, a gradient of the second catalytic
material is also established along a length of the first surface of
the inner partition wall. A gradient of the second catalytic
material along a first surface of the inner partition wall, in some
embodiments, comprises a greater amount of the second catalytic
material at a first end of the inner partition wall in comparison
with an amount of the second catalytic material at a second end of
the inner partition wall, the second end opposite the first
end.
[0181] In some embodiments, a gradient of the second catalytic
material is also established along a length of the second surface
of the inner partition wall. A gradient of the second catalytic
material along the length of the second surface of the inner
partition wall, in some embodiments, comprises a greater amount of
the second catalytic material at a first end of the inner partition
wall in comparison with an amount of the second catalytic material
at a second end of the inner partition wall, the second end
opposite the first end. In some embodiments, the gradient profile
of the second catalytic material along the length of the second
surface of the inner partition wall is symmetrical or substantially
symmetrical to the gradient profile of the second catalytic
material along the length of the first surface of the inner
partition wall.
[0182] In some embodiments, a gradient of bulk second catalytic
material is also established along a width of the inner partition
wall. In some embodiments, bulk second catalytic material of the
gradient decreases in concentration at the periphery of the width
of the inner partition wall. In some embodiments, bulk second
catalytic material increases in concentration along a central
region of the width of the inner partition wall.
[0183] In some embodiments, a gradient of bulk second catalytic
material along the width of the inner partition wall has a profile
symmetrical or substantially symmetrical about the midpoint of the
profile.
[0184] In some embodiments, drying the at least one inner partition
wall of a structural catalyst body described herein also
establishes a gradient of a bulk second catalytic material along a
length of the inner partition wall. In some embodiments, a gradient
of a bulk second catalytic material along a length of the inner
partition wall comprises a greater concentration of the bulk second
catalytic material at a first end of the inner partition wall in
comparison with a concentration of the bulk second catalytic
material at a second end of the inner partition wall, the second
end opposite the first end.
[0185] Moreover, in some embodiments of methods described herein, a
gradient of the second catalytic material is also established along
a width and/or length of one or more surfaces of a plurality of
inner partition walls of the structural catalyst body. In some
embodiments, a gradient of bulk second catalytic material is also
established along a width and/or length of a plurality of inner
partition walls of the structural catalyst body.
[0186] In some embodiments, at least one centerpost of a structural
catalyst body is impregnated with the solution further comprising
the second catalytic material, and drying the structural catalyst
body also establishes a gradient of bulk second catalytic material
between the centerpost and at least one of the inner partition
walls forming the centerpost. In some embodiments, for example, at
least one inner partition wall comprises a greater concentration of
bulk second catalytic material than the centerpost. In some
embodiments, each of the inner partition walls forming the
centerpost comprises a greater concentration of bulk second
catalytic material than the centerpost.
[0187] Additionally, in some embodiments, the outer peripheral wall
of a structural catalyst body described herein is impregnated with
the second catalytic material. In some embodiments wherein the
outer peripheral wall comprises bulk second catalytic material,
inner partition walls of the structural catalyst body comprise a
greater concentration of bulk second catalytic material than the
outer peripheral wall.
[0188] In some embodiments, first and/or second catalytic material
of gradients of structural catalyst bodies produced according to
methods described herein comprise one or more transition metals. In
some embodiments, transition metals of the first and/or second
catalytic material comprise vanadium, tungsten, molybdenum,
platinum, palladium, ruthenium, rhodium, rhenium, iron, gold,
silver, copper or nickel or alloys or oxides thereof. In some
embodiments, the first and/or second catalytic material of
gradients of structural catalyst bodies described herein are
suitable for SCR applications and processes. In some embodiments,
for example, the first and/or second catalytic material comprise
V.sub.2O.sub.5, WO.sub.3 or MoO.sub.3 or mixtures thereof. In some
embodiments, the first and/or second catalytic material comprise
one or more precursors for forming a catalytic material suitable
for SCR applications. In some embodiments, for example, the first
and/or second catalytic material comprise one or more precursors
for forming V.sub.2O.sub.5, WO.sub.3 or MoO.sub.3 or mixtures
thereof.
[0189] In some embodiments, drying inner partition walls and/or
centerposts of a structural catalyst support comprises flowing a
gas over surfaces of the inner partition walls and/or centerposts
at a rate and/or temperature sufficient to establish one or more
gradients of the first catalytic material and/or second catalytic
material described herein. Flowing a gas over surfaces of the inner
partition walls and/or centerposts to establish one or more
gradients of the first catalytic material and/or second catalytic
material described herein can be administered in any manner not
inconsistent with the objectives of the present invention. In some
embodiments, gas is flowed over all or substantially all of the
inner partition walls and/or centerposts of a structural catalyst
support in an even or substantially even manner.
[0190] Additionally, in some embodiments, the impregnation solution
of a method described herein further comprises at least one
additional catalytic material. In such embodiments, drying the
structural catalyst body can provide one or more gradients of the
additional catalytic material having a construction and/or location
on the structural catalyst body consistent with any gradient of the
first and/or second catalytic material described herein.
[0191] In some embodiments, a structural catalyst support is
virgin. A virgin structural catalyst support, in some embodiments,
has not been used or previously installed into a catalytic reactor
for conducting catalytic reactions in a fluid stream.
[0192] In some embodiments, a structural catalyst support is used.
A used structural catalyst support, in some embodiments, has been
previously installed in a catalytic reactor for conducting
catalytic reactions in a fluid stream. In some embodiments, a used
catalyst support is part of a structural catalyst body in need of
regeneration.
[0193] In some embodiments, virgin or used structural catalyst
supports comprise honeycomb-like structural supports, plate
structural supports or corrugated structural supports.
[0194] In some embodiments of methods described herein, structural
catalyst supports comprising a plurality of inner partition walls
are arranged in the framework of a catalyst module. In such
embodiments, the catalyst module comprising the structural catalyst
supports can be immersed in the solution of catalytic material to
impregnate the inner partition walls and/or centerposts of the
structural catalyst supports with catalytic material.
[0195] In some embodiments, the structural catalyst supports
impregnated with a solution of the first catalytic material are
dried while remaining the framework of the catalyst module to
establish one or more gradients of the first catalytic material
described herein. In some embodiments, the impregnation solution
further comprises a second catalytic material wherein drying the
structural catalyst supports while remaining in the framework of
the catalyst module also establishes one or more gradients of the
second catalytic material as described herein. In some embodiments,
for example, a gas is flowed through the module and over surfaces
of the inner partition walls and/or centerposts of the structural
catalyst supports at a rate and/or temperature sufficient to
establish one or more gradients of the first and/or second
catalytic material described herein. In some embodiments, the gas
is flowed evenly or substantially evenly through the structural
catalyst supports arranged in the framework of the module such that
the catalytic activity of the resulting structural catalyst bodies
is substantially uniform across the module. In being substantially
uniform, catalytic activity between catalyst bodies in the module,
in some embodiments, varies less than about 20%. In some
embodiments, in being substantially uniform, catalytic activity
between catalyst bodies of the module varies less than 10%. In some
embodiments, in being substantially uniform, catalytic activity
between catalyst bodies of the module varies less than 5%. In some
embodiments, catalytic activity comprises the selective catalytic
reduction of nitrogen oxides, the oxidation of mercury or the
oxidation of ammonia or combinations thereof.
[0196] In some embodiments, sulfur dioxide oxidation activity of
catalyst bodies of the module is substantially uniform across the
module. In being substantially uniform, sulfur dioxide oxidation
activity between catalyst bodies of the module, in some
embodiments, varies less than 40%. In some embodiments, in being
substantially uniform, sulfur dioxide oxidation activity between
catalyst bodies of the module varies less than 20%. In some
embodiments, in being substantially uniform, sulfur dioxide
oxidation activity between catalyst bodies of the module varies
less than 10%.
[0197] In some embodiments, gradients of first and/or second
catalytic material produced according to the forgoing methods can
have any of the structural and/or compositional properties
described herein for the gradients of the first and/or second
catalytic material. In some embodiments, for example, a structural
catalyst produced according to one or more methods described herein
can have any combination of gradients of first catalytic material
and/or second catalytic material as provided in Table I of FIG.
5.
[0198] In some embodiments of methods described herein, a
structural catalyst support is immersed or dipped into a solution
of catalytic material to impregnate the inner partition walls
and/or centerposts with the solution of catalytic material. In some
embodiments, catalytic material of the solution comprises one or
more transition metals. In some embodiments, transition metals
comprise vanadium, tungsten, molybdenum, platinum, palladium,
ruthenium, rhodium, rhenium, iron, gold, silver, copper or nickel
or alloys or oxides thereof. In some embodiments, one or more
catalytic materials of gradients of structural catalyst bodies
described herein are suitable for SCR applications and processes.
In some embodiments, for example, catalytic material comprises
V.sub.2O.sub.5, WO.sub.3 or MoO.sub.3 or mixtures thereof.
[0199] In some embodiments, the first catalytic material of a
solution described herein comprises a transition metal selected
from the group consisting of vanadium, tungsten, molybdenum,
platinum, palladium, ruthenium, rhodium, rhenium, iron, gold,
silver, copper and nickel and alloys and oxides thereof. Moreover,
in some embodiments, the second catalytic material of a solution
described herein comprises a transition metal selected from the
group consisting of vanadium, tungsten, molybdenum, platinum,
palladium, ruthenium, rhodium, rhenium, iron, gold, silver, copper
and nickel and alloys and oxides thereof. In some embodiments, the
at least one additional catalytic material of a solution described
herein comprises a transition metal selected from the group
consisting of vanadium, tungsten, molybdenum, platinum, palladium,
ruthenium, rhodium, rhenium, iron, gold, silver, copper and nickel
and alloys and oxides thereof.
[0200] In some embodiments, for example, an aqueous solution
comprises first catalytic material of a vanadium salt, such as
vanadyl salts, including vanadyl oxalate, vanadyl sulfate or
ammonium metavanadate or mixtures thereof. In some embodiments, the
aqueous solution further comprises a second catalytic material of a
tungsten salt, such as tungstate salts, including ammonium
metatungstate. In some embodiments, the aqueous solution further
comprises at least one additional catalytic material of a
molybdenum salt, such as ammonium molybdate, sodium molybdate or
mixtures thereof.
[0201] A catalytic material can be present in a solution for
impregnating the catalyst support in any amount not inconsistent
with the objectives of the present invention.
[0202] In some embodiments, a structural catalyst support is
immersed in a solution of the first, second and/or additional
catalytic material for any desired amount of time not inconsistent
with the objectives of the present invention. In some embodiments,
a structural catalyst support is immersed in a solution of
catalytic material for a time period of at least about 5 seconds.
In some embodiments, a structural catalyst support is immersed in a
solution of catalytic material for a time period of at least about
10 seconds or at least about 30 seconds. In some embodiments, a
structural catalyst support is immersed in a solution of catalytic
material for a time period of at least about 1 minute. In some
embodiments, a structural catalyst support is immersed in a
solution of catalytic material for a time period of at least about
5 minutes or at least about 10 minutes. A structural catalyst
support, in some embodiments, is immersed in a solution of
catalytic material for a time period ranging from about 1 minute to
about 15 minutes.
[0203] In some embodiments, pore surfaces and/or other surfaces of
a structural catalyst support are not treated with a blocking fluid
or other agent having the ability to inhibit or facilitate
impregnation of the solution of catalytic material into the inner
partition walls and/or centerposts prior or subsequent to immersing
the structural catalyst body in the solution of catalytic
material.
[0204] In some embodiments, a structural catalyst support is fully
immersed in the solution of catalytic material. In some
embodiments, a catalyst support is only partially immersed in the
solution of catalytic material.
[0205] Moreover, in some embodiments of methods described herein,
structural catalyst supports comprising a plurality of inner
partition walls are arranged in the framework of a catalyst module.
In such embodiments, the catalyst module comprising the structural
catalyst supports can be immersed in the solution of the first,
second and/or additional catalytic material to impregnate the inner
partition walls and/or centerposts of the structural catalyst
supports with catalytic material.
[0206] Inner partition walls and/or centerposts of a structural
catalyst support are dried to establish one or more gradients of
the first, second and/or additional catalytic material described
herein. In some embodiments, drying inner partition walls and/or
centerposts of a structural catalyst support comprises flowing a
gas over surfaces of the inner partition walls and/or centerposts
at a rate and/or temperature sufficient to establish one or more of
the gradients of catalytic material described herein.
[0207] A gas flowed over surfaces of the inner partition walls
and/or centerposts of a structural catalyst support during the
drying process can have any desired flow rate consistent with
establishing one or more gradients of catalytic material described
herein. In some embodiments, a gas has a flow rate according to any
of the ranges set forth in Table I.
TABLE-US-00001 TABLE I Drying Gas Flow Rate (m/s) 0.1-1 1-2 2-3 3-4
4-5 5-6 6-7 7-8 8-9 9-10 >10
[0208] Moreover, a gas flowed over surfaces of the inner partition
walls and/or centerposts of a structural catalyst support during
the drying process can have any desired temperature consistent with
establishing one or more gradients of catalytic material described
herein. The gas, in some embodiments, is heated to a temperature of
at least about 140.degree. C. In some embodiments, the gas is
heated to a temperature of at least about 160.degree. C. In some
embodiments, the gas is heated to a temperature ranging from about
100.degree. C. to about 350.degree. C. In some embodiments, the gas
is heated to a temperature greater than 350.degree. C.
[0209] In some embodiments, the flow rate of the gas and the
temperature of the gas can be mutually or independently adjusted to
produce gradients of catalytic material of varying degree along
widths of inner partition walls of a structural catalyst support in
the production of a structural catalyst body.
[0210] A gas suitable for flowing over surfaces of one or more
inner partition walls can comprise any gas not inconsistent with
establishing one or more gradients of catalytic material described
herein. In some embodiments, a gas comprises air. In some
embodiments, a gas comprises nitrogen or argon. In some
embodiments, a gas comprises combustion flue gas. In some
embodiments, a structural catalyst body described herein is
calcined after establishing one or more gradients of catalytic
material.
[0211] Inner partition walls and/or centerposts of a structural
catalyst support can be exposed to the flowing gas for any desired
time period consistent with establishing one or more gradients of
catalytic material described herein. In some embodiments, inner
partition walls and/or centerposts are exposed to the flowing gas
for a time period ranging from about 1 minute to about 1.5 hours.
In some embodiments, inner partition walls and/or centerposts are
exposed to the flowing gas for a time period ranging from about 5
minutes to about 45 minutes. In some embodiments, inner partition
walls and/or centerposts are exposed to the flowing gas for a time
period ranging from about 10 minutes to about 30 minutes.
[0212] Flowing a gas over surfaces of the inner partition walls
and/or centerposts to establish one or more gradients of catalytic
material described herein can be administered in any manner not
inconsistent with the objectives of the present invention. In some
embodiments, gas is flowed over all or substantially all of the
inner partition walls and/or centerposts of a structural catalyst
support in an even or substantially even manner. In some
embodiments, for example, a conduit is coupled to the open face of
the catalyst support, and gas is flowed through the conduit and
through the flow channels of the structural catalyst support,
thereby flowing evenly or substantially evenly over the inner
partition walls and/or centerposts. In some embodiments, the
conduit is sealed to the open face of the structural catalyst
support or preclude or inhibit air flow along exterior surfaces of
the structural catalyst support.
[0213] In some embodiments, a diffuser is positioned in front of
the open face of the catalyst support to assist in providing an
even or substantially even flow of the gas through the structural
catalyst body during the drying process. In some embodiments, a
diffuser can comprise a perforated plate. Additionally, in some
embodiments, a diffuser can be used alone or in conjunction with a
conduit.
[0214] In some embodiments, the structural catalyst supports
impregnated with a solution of the first, second and/or additional
catalytic material are dried while remaining the framework of the
catalyst module to establish one or more gradients of catalytic
material described herein. In some embodiments, for example, a gas
is flowed through the module and over surfaces of the inner
partition walls and/or centerposts of the structural catalyst
supports at a rate and/or temperature sufficient to establish one
or more gradients of catalytic material described herein.
[0215] In some embodiments, the gas is flowed evenly or
substantially evenly through the structural catalyst supports
arranged in the framework of the module such that the catalytic
activity of the resulting structural catalyst bodies is
substantially uniform across the module. In being substantially
uniform, catalytic activity between catalyst bodies in the module,
in some embodiments, varies less than about 20%. In some
embodiments, in being substantially uniform, catalytic activity
between catalyst bodies of the module varies less than 10%. In some
embodiments, in being substantially uniform, catalytic activity
between catalyst bodies of the module varies less than 5%. In some
embodiments, catalytic activity comprises the selective catalytic
reduction of nitrogen oxides, the oxidation of mercury or the
oxidation of ammonia or combinations thereof.
[0216] In some embodiments, sulfur dioxide oxidation activity of
catalyst bodies of the module is substantially uniform across the
module. In being substantially uniform, sulfur dioxide oxidation
activity between catalyst bodies of the module, in some
embodiments, varies less than 40%. In some embodiments, in being
substantially uniform, sulfur dioxide oxidation activity between
catalyst bodies of the module varies less than 20%. In some
embodiments, in being substantially uniform, sulfur dioxide
oxidation activity between catalyst bodies of the module varies
less than 10%.
[0217] In some embodiments, a conduit is coupled to the open face
of the module and gas is flowed through the conduit and through the
structural catalyst supports in the module. In some embodiments,
the conduit is sealed to the open face of the module to preclude or
inhibit air flow along exterior surfaces of the module.
[0218] In some embodiments, a diffuser is positioned in front of
the open face of the catalyst module to assist in providing an even
or substantially even flow of the gas through the structural
catalyst body during the drying process. In some embodiments, a
diffuser can comprise a perforated plate. Additionally, in some
embodiments, a diffuser can be used alone or in conjunction with a
conduit.
[0219] In another aspect, methods of treating a fluid stream, such
as a flue gas or combustion gas stream are described herein. In
some embodiments, a method of treating a fluid stream comprises
providing a structural catalyst body comprising at least one inner
partition wall comprising a first surface and a second surface
opposite the first surface, the inner partition wall having a
gradient of first catalytic material along a width of the first
surface, passing the fluid stream through the structural catalyst
body and catalytically reacting at least one chemical species in
the fluid stream. In some embodiments, the fluid stream is flowed
through one or more flow channels of the structural catalyst
body.
[0220] In some embodiments, catalytically reacting at least one
chemical species in the fluid stream comprises catalytically
reducing nitrogen oxides in the fluid stream. In some embodiments,
catalytically reacting at least one chemical species in the fluid
stream comprises oxidizing ammonia and/or mercury in the fluid
stream.
[0221] In some embodiments of methods of treating a fluid stream,
oxidation of sulfur dioxide to sulfur trioxide in the fluid stream
is reduced. In one embodiment, for example, oxidation of sulfur
dioxide is reduced during the selective catalytic reduction of
nitrogen oxides in a fluid stream by a structural catalyst body
described herein.
[0222] In some embodiments, catalyst bodies of a method of treating
a fluid stream comprise one or more catalytic gradients described
herein in addition to the gradient of first catalytic material
along the width of a surface of at least one inner partition wall.
In some embodiments, for example, catalyst bodies also comprise a
gradient of bulk first catalytic material along a width and/or
length of at least one inner partition as described herein. In some
embodiments, catalyst bodies of methods described herein can have
any combination of the gradients provided in Table I of FIG. 5.
[0223] In some embodiments, the catalyst body is part of a module
comprising a plurality of catalyst bodies described herein, where
the fluid stream is passed into the module and through the catalyst
bodies. In some embodiments, the module is part of a catalytic
layer of a catalytic reactor.
[0224] These and other embodiments of structural catalyst bodies
are further illustrated by the following non-limiting example.
Example 1
Structural Catalyst Body
[0225] An extrusion composition was provided by mixing TiO.sub.2
powders with fillers, binders, extrusion aids and lubricants. The
extrusion composition contained substantially no vanadium
(<0.10% V.sub.2O.sub.5). The extrusion composition included a
tungsten content of .ltoreq.1.80% WO.sub.3. The extrusion
composition was extruded to provide a structural catalyst support
comprising an outer peripheral wall and a plurality of inner
partition walls. The inner partition walls defined a plurality of
flow channels of the structural catalyst support, the flow channels
having a square cross-sectional profile. The extruded catalyst
support was dried and calcined. Porosity of the structural catalyst
support was determined by a water absorption test.
[0226] A solution of a vanadium first catalytic material and a
tungsten second catalytic material was provided by adding vanadyl
oxalate solution and ammonium metatungstate powder to a container
of deionized water. As understood by one of skill in the art, the
amounts of vanadyl oxalate and ammonium metatungstate added were
determined according to the desired bulk chemistry and porosity of
the structural catalyst support. Solution concentration of
catalytic material was confirmed by x-ray fluorescence (XRF). The
structural catalyst body was immersed in the catalytic material
solution for three minutes and subsequently removed.
[0227] The structural catalyst support impregnated with vanadium
first catalytic material and tungsten second catalytic material was
dried with a hot air blower. The structural catalyst body was
wrapped and sealed in a manner such that heated air received from
the blower flowed through the flow channels and over the inner
partition walls in a substantially even manner. As described
herein, a conduit can be sealed to the face of the structural
catalyst body for delivery of the heated air. The air from the
blower was heated at a rate of 20.degree. C./min to a set point
temperature of 160.degree. C. and held for 30 minutes to dry the
structural catalyst body. The temperature of the air was then
increased to 350.degree. C. at a rate of 20.degree. C./min to
administer a 15 minute calcination of the structural catalyst body.
The resulting structural catalyst body demonstrated a gradient of
first (V.sub.2O.sub.5) and second (WO.sub.3) catalytic materials
consistent with that illustrated in FIG. 1.
[0228] Moreover, the catalytic activity of structural catalyst
bodies produced in accordance with this example for the selective
catalytic reduction of nitrogen oxides and sulfur dioxide oxidation
was measured. The catalytic activity of the structural catalyst
bodies was compared to a prior structural catalyst bodies lacking
gradients of first and second catalytic material along widths of
the inner partition walls. FIG. 4 illustrates the results of the
catalytic activity testing. As illustrated in FIG. 4, the
structural catalyst bodies of the present example (A) demonstrated
significantly higher rate for the selective reduction of nitrogen
oxides per unit of sulfur dioxide oxidation in comparison to the
prior catalyst bodies (B).
[0229] Various embodiments of the invention have been described in
fulfillment of the various objects of the invention. It should be
recognized that these embodiments are merely illustrative of the
principles of the present invention. Numerous modifications and
adaptations thereof will be readily apparent to those skilled in
the art without departing from the spirit and scope of the
invention.
[0230] That which is claimed is:
* * * * *