US4071601A
Expired / Lapsed
US
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Selective removal of nitrogen oxides from waste gases using V-Mo-W catalysts
Assignee: Sumitomo Chemical Co Ltd
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Filing: 1976-02-27
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Granted: 1978-01-31
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Expires: 1996-02-27
Abstract
Abstract A process for selective removal of nitrogen oxides from waste gases containing 1,500 ppm or less (gas volume) of nitrogen oxides by contacting the waste gases with a metal oxide catalyst containing vanadium oxide and at least one of molybdenum oxide and tungsten oxide with an atomic ratio of the oxide forming elements of:
Inventors
- 👤 Tatsuo Shiraishi
- 👤 Shinkichi Shimizu
- 👤 Tadashi Shindo
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 07:27
CPC Classifications
B; B01; B01J; B01J23/00; B01J23/16; B01J23/24; B01J23/30; B01D; B01D53/00; B01D53/34; B01D53/92; B01D53/94; B01D53/9404; B01D53/9409; B01D53/9413; B01D53/9418; B01J23/20; B01J23/22; B01J23/28; B01D2251/00; B01D2251/20; B01D2251/206; B01D2251/2062; B01D2255/00; B01D2255/20; B01D2255/207; B01D2255/20723; B01D2255/20769; B01D2255/20776
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
100 words
A process for the selective removal of nitrogen oxides from waste gases containing 1,500 ppm or less in gas volume of nitrogen oxides, which comprises reducing said nitrogen oxides with ammonia by contacting said waste gases with ammonia in the presence of a complex metal oxide catalyst consisting essentially of vanadium oxide and at least one member selected from the group consisting of molybdenum oxide and tungsten oxide with an atomic ratio of the oxide forming elements of: V.sub.12-x-y Mo.sub.x W.sub.y wherein 0 ≦ x ≦ 8, 0 ≦ y ≦ 5 and 0.3 ≦ x + y ≦ 8.
Claim 2
Dependent Claim
100 words
A process for the selective removal of nitrogen oxides from waste gases containing 1,500 ppm or less in gas volume of nitrogen oxides, which comprises reducing said nitrogen oxides with ammonia by contacting said waste gases with ammonia in the presence of a complex metal oxide catalyst consisting essentially of vanadium oxide and at least one member selected from the group consisting of molybdenum oxide and tungsten oxide with an atomic ratio of the oxide forming elements of: V.sub.12-x-y Mo.sub.x W.sub.y wherein 0 ≦ x ≦ 8, 0 ≦ y ≦ 5 and 0.3 ≦ x + y ≦ 8.
Claim 3
Dependent Claim
29 words
The process according to claim 1, wherein the catalyst has the atomic ratio of the oxide forming elements of V 12-x Mo x wherein 2 ≦ x ≦ 8.
Claim 4
Dependent Claim
29 words
The process according to claim 1, wherein the catalyst has the atomic ratio of the oxide forming elements of V 12-y W y wherein 0.3 ≦ y ≦ 5.
Claim 5
Dependent Claim
44 words
The process according to claim 1, wherein the catalyst has the atomic ratio of the oxide forming elements of V 12-x-y Mo x W y wherein 0 ≦ x ≦ 4, 0 ≦ y ≦ 3 and 1 ≦ x + y ≦ 5.
Claim 6
Dependent Claim
26 words
The process according to claim 1, wherein the ammonia is added in an amount of 0.3 to 4 moles per 1 mole of the nitrogen oxides.
Claim 7
Dependent Claim
27 words
The process according to claim 5, wherein the amount of ammonia is in the range of 0.7 to 3 moles per 1 mole of the nitrogen oxides.
Claim 8
Dependent Claim
27 words
The process according to claim 1, wherein the contact of the waste gases with the catalyst is carried out at a temperature of 150° to 700° C.
Claim 9
Dependent Claim
18 words
The process according to claim 7, wherein the temperature is in the range of 200° to 400° C.
Claim 10
Dependent Claim
26 words
The process according to claim 1, wherein the waste gases are contacted with the catalyst at a space velocity of 2,000 to 100,000 hr -1 .
Claim 11
Dependent Claim
21 words
The process according to claim 9, wherein the space velocity is in the range of 6,000 to 30,000 hr -1 .
Claim 12
Dependent Claim
120 words
A process for the selective removal of nitrogen oxides from waste gases containing 100 to 1,500 ppm in gas volume of nitrogen oxides, which comprises reducing said nitrogen oxides with ammonia by contacting said waste gases with ammonia in the presence of a complex metal oxide catalyst consisting essentially of vanadium oxide and at least one member selected from the group consisting of molybdenum oxide and tungsten oxide with an atomic ratio of the oxide forming elements of: V.sub.12-x-y Mo.sub.x W.sub.y wherein 0 ≦ x ≦ 8, 0 ≦ y ≦ 5 and 0.3 ≦ x + y ≦ 8, at a temperature of 150° to 700° C. and at a space velocity of 2,000 to 100,000 hr -1 .
Claim 13
Dependent Claim
120 words
A process for the selective removal of nitrogen oxides from waste gases containing 100 to 1,500 ppm in gas volume of nitrogen oxides, which comprises reducing said nitrogen oxides with ammonia by contacting said waste gases with ammonia in the presence of a complex metal oxide catalyst consisting essentially of vanadium oxide and at least one member selected from the group consisting of molybdenum oxide and tungsten oxide with an atomic ratio of the oxide forming elements of: V.sub.12-x-y Mo.sub.x W.sub.y wherein 0 ≦ x ≦ 8, 0 ≦ y ≦ 5 and 0.3 ≦ x + y ≦ 8, at a temperature of 150° to 700° C. and at a space velocity of 2,000 to 100,000 hr -1 .
Claim 14
Dependent Claim
26 words
The process according to claim 11, wherein the ammonia is employed in an amount of 0.3 to 4 moles per 1 mole of the nitrogen oxides.
Claim 15
Dependent Claim
88 words
A process for the selective removal of nitrogen oxides from waste gases containing 1,500 ppm or less in gas volume of nitrogen oxides, which comprises reducing said nitrogen oxides with ammonia by contacting said waste gases with ammonia in the presence of a metal oxide catalyst consisting essentially of vanadium oxide, molybdenum oxide and tungsten oxide with an atomic ratio of the oxide forming elements of: V.sub.12-x-y Mo.sub.x -W.sub.y wherein 0 ≦ x ≦ 4, 0 ≦ y ≦ 3 and 1 ≦ x + y ≦ 5.
Claim 16
Dependent Claim
88 words
A process for the selective removal of nitrogen oxides from waste gases containing 1,500 ppm or less in gas volume of nitrogen oxides, which comprises reducing said nitrogen oxides with ammonia by contacting said waste gases with ammonia in the presence of a metal oxide catalyst consisting essentially of vanadium oxide, molybdenum oxide and tungsten oxide with an atomic ratio of the oxide forming elements of: V.sub.12-x-y Mo.sub.x -W.sub.y wherein 0 ≦ x ≦ 4, 0 ≦ y ≦ 3 and 1 ≦ x + y ≦ 5.
Claim 17
Dependent Claim
26 words
The process according to claim 13, wherein the ammonia is added in an amount of 0.3 to 4 moles per 1 mole of the nitrogen oxides.
Claim 18
Dependent Claim
39 words
The process according to claim 14, wherein the contact of the waste gases with the catalyst is carried out at a temperature of 150° to 700° C. and at a space velocity of 2,000 to 100,000 hr -1 .
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) | 1981-01-30 | 1981-08-01 | 1982-01-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-01-30 | 1985-08-01 | 1986-01-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-01-30 | 1989-08-01 | 1990-01-31 | $7700.00 | Window Closed / Lapsed |