Patent US3976745A successfully refreshed from Google Patents.
US3976745A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for reducing nitrogen oxides to nitrogen
Assignee: Mitsubishi Chemical Corp
•
Filing: 1974-12-10
•
Granted: 1976-08-24
•
Expires: 1994-12-10
Abstract
Abstract A catalyst composition for reducing nitrogen oxides, which is characterized in that the same contains, as its chief ingredient, A. tin (Sn) as the component A, and B. at least one metal selected from the group consisting of molybdenum (Mo), tungsten (W), and iron (Fe), as the component (B).
Inventors
- 👤 Fumito Nakajima
- 👤 Masato Tekeuchi
- 👤 Shimpei Matsuda
- 👤 Shigeo Uno
- 👤 Toshikatsu Mori
- 👤 Yoshihisa Watanabe
- 👤 Makoto Imanari
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 23:04
CPC Classifications
B; B01; B01J; B01J23/00; B01J23/70; B01J23/76; B01J23/835; B01D; B01D53/00; B01D53/34; B01D53/92; B01D53/94; B01D53/9404; B01D53/9409; B01D53/9413; B01D53/9418; B01J23/16; B01J23/24; B01D2255/00; B01D2255/20; B01D2255/207; B01D2255/20738; B01D2255/20769; B01D2255/20776; B01D2255/209; B01D2255/2094
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
70 words
A process for reducing nitrogen oxides to nitrogen, which comprises contacting a gaseous mixture containing nitrogen oxides and molecular oxygen and ammonia with the catalyst composition containing as its chief ingredient; A. tin as the component A, and B. at least one metal selected from the group consisting of molybdenum, tungsten, and iron, as the component B, in the form of an intimate mixture of their oxides, at elevated temperatures.
Claim 2
Dependent Claim
70 words
A process for reducing nitrogen oxides to nitrogen, which comprises contacting a gaseous mixture containing nitrogen oxides and molecular oxygen and ammonia with the catalyst composition containing as its chief ingredient; A. tin as the component A, and B. at least one metal selected from the group consisting of molybdenum, tungsten, and iron, as the component B, in the form of an intimate mixture of their oxides, at elevated temperatures.
Claim 3
Dependent Claim
16 words
The process according to claim 1, in which the elevated temperature ranges from 160° to 640°C.
Claim 4
Dependent Claim
16 words
The process according to claim 1, in which the elevated temperature ranges from 250° to 500°C.
Claim 5
Dependent Claim
28 words
The process according to claim 1 in which the gaseous mixture contains at least 1/4 mol of molecular oxygen per mol of the nitric oxide (NO) contained therein.
Claim 6
Dependent Claim
33 words
The process according to claim 1 in which ammonia as the reducing gas is used at the ratio of 0.5-10 molar times the nitrogen oxide (NO x ) contained in the gaseous mixture.
Claim 7
Dependent Claim
22 words
The process of claim 1 wherein the atomic ratio of tin to component B, as the metal, ranges from 1:0.01 to 1:1.0.
Claim 8
Dependent Claim
22 words
The process of claim 1 wherein the atomic ratio of tin to component B, as the metal, ranges from 1:0.02 to 1:0.5.
Claim 9
Dependent Claim
16 words
The process of claim 1 wherein said catalyst composition is supported on an inert, solid carrier.
Claim 10
Dependent Claim
17 words
The process of claim 1 wherein said gaseous mixture is flue gas which further includes sulfur oxides.
Claim 11
Dependent Claim
60 words
The process of claim 1 wherein the component B metal is iron and said gaseous mixture containing nitrogen oxides and molecular oxygen and ammonia are contacted with said catalyst composition at a temperature of from 160°C to 300°C and, wherein the atomic ratio of tin to iron in said catalyst composition is in the range of from 1:1 to 1:20.
Claim 12
Dependent Claim
21 words
The process of claim 10 wherein up to 50% by weight of the iron is in the form of iron sulfates.
Claim 13
Dependent Claim
51 words
The process of claim 1 wherein said catalyst composition further includes a minor amount of (C) at least one metal selected from the group consisting of copper, magnesium, aluminum, boron, titanium, silicon, antimony, vanadium, cobalt, nickel and manganese, the atomic ratio of component (C) to tin being no greater than 0.02:1.
Claim 14
Dependent Claim
12 words
The process of claim 1 wherein the component B metal is molybdenum.
Claim 15
Dependent Claim
12 words
The process of claim 1 wherein the component B metal is tungsten.
Claim 16
Dependent Claim
34 words
The process of claim 1 wherein the component B metal is iron and wherein the atomic ratio of iron to tin in said catalyst composition is in the range of from 9.5:0.5 to 1:9.
Claim 17
Dependent Claim
36 words
The process of claim 15 wherein said catalyst composition is supported on an inert, solid carrier and wherein said catalyst composition includes at least 5% by weight of iron, calculated as Fe 2 O 3 .
Claim 18
Dependent Claim
21 words
The process of claim 13 wherein the atomic ratio of tin to molybdenum is within the range of 8:2 to 9.5:0.5.
Claim 19
Dependent Claim
21 words
The process of claim 14, wherein the atomic ratio of tin to tungsten is within the range of 8:2 to 9.5:0.5.
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) | 1979-08-24 | 1980-02-23 | 1980-08-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-08-24 | 1984-02-23 | 1984-08-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-08-24 | 1988-02-23 | 1988-08-24 | $7700.00 | Window Closed / Lapsed |