US4466947A
Expired / Lapsed
US
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Denitration catalyst and denitrating method
Assignee: Mitsubishi Chemical Corp
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Filing: 1983-01-07
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Granted: 1984-08-21
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Expires: 2003-01-07
Abstract
Abstract A denitration catalyst comprising at least three metal components, (A) titanium, (B) tungsten and/or magnesium, and (C) vanadium, the titanium and tungsten being contained as oxides and the magnesium and vanadium being contained in the form of an oxide or a sulfate or both, said catalyst being composed of a porous molded article of a mixture of an oxide of component A and an oxide and/or a sulfate of component B, the atomic ratio of component B to component A being from 0.01 to 1, and a vanadium compound localized in that area of said molded article which extends from its outermost surface to a depth of 500 microns or less, the content of the vanadium compound in said area being 0.1 to 15% by weight; and a method for removing nitrogen oxides from a waste gas, which comprises contacting a waste gas containing nitrogen oxides, together with ammonia and molecular oxygen, at a temperature of 150 DEG to 650 DEG C., with the aforesaid catalyst.
Inventors
- 👤 Makoto Imanari
- 👤 Bunzi Oshida
- 👤 Yusaku Arima
- 👤 Hirokazu Tanaka
- 👤 Yoshinori Todo
- 👤 Norihisa Kobayashi
- 👤 Toshikuni Sera
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 12:31
CPC Classifications
B; B01; B01J; B01J23/00; B01J23/16; B01J23/20; B01J23/22; B01D; B01D53/00; B01D53/34; B01D53/92; B01D53/94; B01D53/9404; B01D53/9409; B01D53/9413; B01D53/9418; B01D2251/00; B01D2251/20; B01D2251/206; B01D2251/2062; B01D2255/00; B01D2255/20; B01D2255/204; B01D2255/2047; B01D2255/207; B01D2255/20707; B01D2255/20723; B01D2255/20776
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
155 words
A denitration catalyst for a waste gas containing nitrogen oxides and sulfur dioxide comprising at least three metal components, (A) titanium, (B) tungsten and/or magnesium, and (C) vanadium, the titanium and tungsten being contained as oxides and the magnesium and vanadium being contained in the form of an oxide or a sulfate or both, said catalyst being composed of a porous molded article of a mixture of an oxide of titanium as component A and at least one member of the group consisting of an oxide of tungsten, an oxide of magnesium and a sulfate of magnesium as component B, the atomic ratio of component B to component A being from 0.01 to 1, and a vanadium compound localized in that area of said molded article which extends from its outermost surface to a depth of 500 microns or less, the content of the vandium compound in said area being 0.1 to 15% by weight.
Claim 2
Dependent Claim
155 words
A denitration catalyst for a waste gas containing nitrogen oxides and sulfur dioxide comprising at least three metal components, (A) titanium, (B) tungsten and/or magnesium, and (C) vanadium, the titanium and tungsten being contained as oxides and the magnesium and vanadium being contained in the form of an oxide or a sulfate or both, said catalyst being composed of a porous molded article of a mixture of an oxide of titanium as component A and at least one member of the group consisting of an oxide of tungsten, an oxide of magnesium and a sulfate of magnesium as component B, the atomic ratio of component B to component A being from 0.01 to 1, and a vanadium compound localized in that area of said molded article which extends from its outermost surface to a depth of 500 microns or less, the content of the vandium compound in said area being 0.1 to 15% by weight.
Claim 3
Dependent Claim
18 words
The catalyst of claim 1 wherein the content of the vanadium compound is 0.3 to 6% by weight.
Claim 4
Dependent Claim
31 words
The catalyst of claim 1 wherein the vanadium compound is localized in an area extending from the outermost surface of said molded article to a depth of at least 30 microns.
Claim 5
Dependent Claim
13 words
The catalyst of claim 3 wherein the depth is at least 50 microns.
Claim 6
Independent Claim
181 words
A method of removing nitrogen oxides from a waste gas, which comprises contacting a waste gas containing nitrogen oxides and sulfur dioxide, together with ammonia and molecular oxygen, at a temperature of 150° to 650° C., with a catalyst comprising at least three metal components, (A) titanium, (B) tungsten and/or magnesium and (C) vanadium, the titanium and tungsten being contained as oxides and the magnesium and vanadium being contained in the form of an oxide or a sulfate or both, said catalyst being composed of a porous molded article of a mixture of an oxide of titanium as component A and at least one member of the group consisting of an oxide of tungsten, an oxide of magnesium and a sulfate of magnesium as component B, the atomic ratio of component B to component A being from 0.01 to 1, and a vanadium compound localized in that area of said molded article which extends from its outermost surface to a depth of 500 microns or less, the content of the vanadium compound in said area being 0.1 to 15% by weight.
Claim 7
Independent Claim
181 words
A method of removing nitrogen oxides from a waste gas, which comprises contacting a waste gas containing nitrogen oxides and sulfur dioxide, together with ammonia and molecular oxygen, at a temperature of 150° to 650° C., with a catalyst comprising at least three metal components, (A) titanium, (B) tungsten and/or magnesium and (C) vanadium, the titanium and tungsten being contained as oxides and the magnesium and vanadium being contained in the form of an oxide or a sulfate or both, said catalyst being composed of a porous molded article of a mixture of an oxide of titanium as component A and at least one member of the group consisting of an oxide of tungsten, an oxide of magnesium and a sulfate of magnesium as component B, the atomic ratio of component B to component A being from 0.01 to 1, and a vanadium compound localized in that area of said molded article which extends from its outermost surface to a depth of 500 microns or less, the content of the vanadium compound in said area being 0.1 to 15% by weight.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-08-21 | 1988-02-20 | 1988-08-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-08-21 | 1992-02-20 | 1992-08-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-08-21 | 1996-02-20 | 1996-08-21 | $7700.00 | Window Closed / Lapsed |