EP0559844B1
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EP
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Palladium partial combustion catalysts and a process for using them
Assignee: Catalytica Inc En Tanaka Kikinzoku Kogyo Kabua
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Filing: 1991-11-26
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Granted: 1999-02-10
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Expires: 2011-11-26
Abstract
Abstract This invention is a catalyst comprising palladium on a support (102) and a partial combustion process in which the fuel is partially combusted using that catalyst. The palladium catalyst (106) may also comprise palladium mixed with metals selected from Group VIII or IB, may be graded (Fig. 1b) such as to have higher activity in the forward edge (112) of the catalyst, or may be placed on a support comprising zirconia. The choice of catalysts (106) and supports (102, 110) specified each solves a variety of problems dealing with the long term stability of the palladium as a partial combustion catalyst. The catalyst structure is stable in operation, has a comparatively low operating temperature, has a low temperature at which oxidation begins, and yet is not susceptible to temperature "runaway". The combustion gas produced by the catalytic process typically is at a temperature below the autocombustive temperature and may be used at that temperature or it may be fed to other combustion stages for further use in a gas turbine, furnace, boiler, or the like.
Inventors
- 👤 Ralph A. Dalla Betta
- 👤 Kazunori Tsurumi
- 👤 Toru Shoji
- 👤 Nobuyasu Ezawa
- 👤 Fabio H. Ribiero
- 👤 Robert L. Garten
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-01 10:07
CPC Classifications
F; F01; F01N; F01N3/00; F01N3/08; F01N3/10; F01N3/24; F01N3/28; F01N3/2803; F01N3/2807; F01N3/281; B; B01; B01D; B01D53/00; B01D53/34; B01D53/74; B01D53/86; B01D53/8621; B01D53/8625; B01D53/8628; B01J; B01J23/00; B01J23/38; B01J23/40; B01J23/44; B01J37/00; B01J37/02; B01J37/0215; B01J37/0225; F01N2330/00; F01N2330/02; F01N2330/30; F01N2330/32; F01N2510/00; F01N2510/06; F01N2510/068; F01N2510/0682
Claims Analysis
Total Claims: 37
Claim 1
Independent Claim
114 words
A partial combustion process comprising the steps of: (a) mixing an amount of an oxygen-containing gas with a combustible fuel to
produce a combustible gas mixture; and, (b) passing the combustible gas mixture into a combustion zone containing a
catalyst configuration comprising palladium catalyst on at least a portion of a
catalyst support comprising a ferrous alloy coated with a washcoat comprising
zirconia and having passageways for the passage and partial combustion of the
combustible gas mixture to produce a partially combusted exhaust gas having a
bulk temperature less than the adiabatic combustion temperature of the combustible
gas mixture and a catalyst temperature no higher than the TGA transition
temperature for the palladium catalyst.
Claim 2
Dependent Claim
12 words
The process of Claim 1, where the palladium catalyst additionally comprises silver.
Claim 3
Dependent Claim
23 words
The process of Claim 1, where the palladium catalyst is at least partially covered by
a diffusion layer or another catalytically inactive oxide.
Claim 4
Dependent Claim
11 words
The process of Claim 3, where the diffusion barrier comprises zirconia.
Claim 5
Dependent Claim
12 words
The process of Claim 3, where the diffusion layer is a washcoat.
Claim 6
Dependent Claim
31 words
The process of Claim 1, where the combustible gas comprises methane and the
combustible gas mixture is passed into the partial combustion zone at a temperature
of at least approximately 325°C.
Claim 7
Dependent Claim
20 words
The process of Claim 1, where the partial combustion zone has a gauge pressure
between -25 kPa and 3.5 MPa.
Claim 8
Dependent Claim
22 words
The process of Claim 1, where the catalyst support has longitudinal passageways in
the form of a honeycomb, tubes, or rolled corrugation.
Claim 9
Dependent Claim
16 words
The process of Claim 8, where only a portion of the longitudinal passageway
surfaces contain palladium.
Claim 10
Dependent Claim
35 words
The process of Claim 1, where the portion of the longitudinal passageways surfaces
containing palladium are adjacent to passageway surfaces not containing palladium
and those surfaces are in integral heat exchange relationship to each other.
Claim 11
Dependent Claim
30 words
The process of Claim 1, where the passageways have a leading zone containing a
relatively higher activity palladium-containing catalyst and a trailing zone
containing a relatively lower activity palladium-containing catalyst.
Claim 12
Dependent Claim
24 words
The process of Claim 11, where the leading zone comprises palladium at a
relatively higher concentration than the palladium concentration in the trailing
zone.
Claim 13
Dependent Claim
21 words
The process of Claim 11, where the leading zone comprises palladium in a
relatively thicker layer than in the following zone.
Claim 14
Dependent Claim
18 words
The process of Claim 11, where the trailing zone additionally comprises a diffusion
barrier on the palladium-containing catalyst.
Claim 15
Dependent Claim
127 words
A partial combustion process comprising the steps of: (a) mixing an amount of air and methane to produce a combustible gas mixture
having an adiabatic combustion temperature substantially above 900°C; and, (b) passing the combustible gas mixture into a combustion zone containing a
catalyst support of a spiral of corrugated ferrous alloy sheet coated with a washcoat
comprising zirconia and having longitudinal passageways for the passage and
partial combustion of the combustible gas mixture and having a catalyst comprising
palladium catalyst in at least a portion of the passageways in said support, to
produce a partially combusted exhaust gas having a bulk temperature less than the
adiabatic combustion temperature of the combustible gas mixture and a catalyst
temperature less than the TGA temperature of the palladium catalyst.
Claim 16
Dependent Claim
24 words
The process of Claim 15, where the catalyst comprising palladium is at least
partially covered by a diffusion barrier comprising a catalytically inactive oxide.
Claim 17
Dependent Claim
12 words
The process of Claim 15, where the palladium catalyst additionally comprises
silver.
Claim 18
Dependent Claim
27 words
The process of Claim 15, where the combustible gas mixture is preheated to a
temperature of more than approximately 325°C prior to passage into the
combustion zone.
Claim 19
Dependent Claim
18 words
The process of Claim 15, where only a portion of the surfaces of the longitudinal
passageways comprise palladium.
Claim 20
Dependent Claim
15 words
The process of Claim 15, where only a portion of the longitudinal passageways
comprise palladium.
Claim 21
Dependent Claim
38 words
The process of Claim 19, where the portion of the surfaces of the longitudinal
passageway surfaces containing palladium are adjacent to passageway surfaces not
containing palladium and those surfaces are in integral heat exchange relationship
to each other.
Claim 22
Dependent Claim
30 words
The process of Claim 15, where the passageways have a leading zone containing a
relatively higher activity palladium-containing catalyst and a trailing zone
containing a relatively lower activity palladium-containing catalyst.
Claim 23
Dependent Claim
24 words
The process of Claim 22, where the leading zone comprises palladium at a
relatively higher concentration than the palladium concentration in the trailing
zone.
Claim 24
Dependent Claim
21 words
The process of Claim 22, where the leading zone comprises palladium in a
relatively thicker layer than in the following zone.
Claim 25
Dependent Claim
79 words
A catalyst structure comprised of: (a) a metallic catalyst support comprising a ferrous alloy having passageways
adapted for the passage of combustible gas and having surfaces in those
passageways for the placement of a catalyst material; (b) a catalyst material comprising palladium on zirconia on at least a portion of
the metallic support passageways; and, (c) a diffusion layer comprising a refractory oxide which is catalytically
inactive in the combustion of the combustible gas, upon the palladium catalytic
material.
Claim 26
Dependent Claim
14 words
The structure of Claim 25, where the metallic catalyst support comprises a ferrous
alloy.
Claim 27
Dependent Claim
37 words
The structure of Claim 25, additionally comprising a covering on at least a portion
of the passageways of a member selected from the group of alumina, zirconia,
silica, titania, refractory metal oxides, non-catalytic oxides, or mixtures thereof.
Claim 28
Dependent Claim
10 words
The structure of Claim 27, where the covering comprises zirconia.
Claim 29
Dependent Claim
11 words
The structure of Claim 28, where the diffusion barrier comprises zirconia.
Claim 30
Dependent Claim
27 words
The structure of Claim 25, where the catalyst material additionally comprises one
or more adjunct catalyst metals selected from silver, gold, platinum, ruthenium,
rhodium, iridium, or osmium.
Claim 31
Dependent Claim
11 words
The structure of Claim 30, where the adjunct catalyst is silver.
Claim 32
Dependent Claim
22 words
The structure of Claim 26, where the metallic catalyst support comprises a
corrugated steel sheet having opposite surfaces rolled into a monolith.
Claim 33
Dependent Claim
26 words
The structure of Claim 32, where the metallic catalyst support additionally
comprises a steel separator sheet adjacent the corrugated steel sheet all rolled into a
monolith.
Claim 34
Dependent Claim
18 words
The structure of Claim 32, where catalyst material is placed on alternating surfaces
on the corrugated steel sheet.
Claim 35
Dependent Claim
30 words
The structure of Claim 25, where the passageways have a leading zone containing a
relatively higher activity palladium-containing catalyst and a trailing zone
containing a relatively lower activity palladium-containing catalyst.
Claim 36
Dependent Claim
24 words
The structure of Claim 35, where the leading zone comprises palladium at a
relatively higher concentration than the palladium concentration in the trailing
zone.
Claim 37
Dependent Claim
21 words
The structure of Claim 35, where the leading zone comprises palladium in a
relatively thicker layer than in the following zone.
References Cited (Backward Citations)
No citation records indexed.
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