US4865827A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for removing nitrogen oxides
Assignee: Mitsubishi Power Ltd
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Filing: 1988-05-17
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Granted: 1989-09-12
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Expires: 2008-05-17
Abstract
Abstract A process for removing nitrogen oxides from exhaust gases containing at least nitrogen oxides and volatile metal compounds by the use of a catalyst having prevented activity reduction due to the volatile metal compounds and having a superior durability is provided, which process comprises contacting the exhaust gases with a catalyst containing TiO 2 , a compound active to nitrogen oxides-removing reaction such as oxides of V, Cr, Mo, W, Fe, Co, Ni, Cu, Ce, etc. and/or sulfates thereof and a metal sulfate containing water of crystallization such as those of Al, Mg or Mn, in the presence of ammonia at 150° to 600° C.
Inventors
- 👤 Takahiro Tachi
- 👤 Hiroshi Kawagoshi
- 👤 Akira Kato
- 👤 Hisao Yamashita
- 👤 Tomoichi Kamo
- 👤 Shinpei Matsuda
- 👤 Yasuyoshi Kato
- 👤 Fumito Nakajima
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 15:18
CPC Classifications
B; B01; B01J; B01J27/00; B01J27/02; B01J27/053; B01D; B01D53/00; B01D53/34; B01D53/74; B01D53/86; B01D53/8621; B01D53/8625; B01D53/8628
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
127 words
A process for removing nitrogen oxides from exhaust gases containing at least nitrogen oxides and volatile metal compounds, which process comprising contacting said exhaust gases in the presence of ammonia at a temperature of 150° to 600° C. with a catalyst containing titanium oxide; a component active to nitrogen oxides-removing reaction, the component selected from the group comprising oxides or sulfates of vanadium, chromium, chromium, molybdenum, tungsten, iron, cobalt, nickel, copper and cerium; and a metal sulfate containing water of crystallization, the metal selected from the group comprising aluminum, magnesium and manganese; wherein the atomic ratio of the titanium to the component active to nitrogen oxides-removing reaction ranges from 99:1 to 70:30, and the metal sulfate containing water of crystallization comprises 4-30% of the catalyst by weight.
Claim 2
Dependent Claim
127 words
A process for removing nitrogen oxides from exhaust gases containing at least nitrogen oxides and volatile metal compounds, which process comprising contacting said exhaust gases in the presence of ammonia at a temperature of 150° to 600° C. with a catalyst containing titanium oxide; a component active to nitrogen oxides-removing reaction, the component selected from the group comprising oxides or sulfates of vanadium, chromium, chromium, molybdenum, tungsten, iron, cobalt, nickel, copper and cerium; and a metal sulfate containing water of crystallization, the metal selected from the group comprising aluminum, magnesium and manganese; wherein the atomic ratio of the titanium to the component active to nitrogen oxides-removing reaction ranges from 99:1 to 70:30, and the metal sulfate containing water of crystallization comprises 4-30% of the catalyst by weight.
Claim 3
Dependent Claim
53 words
A process for removing nitrogen oxides according to claim 1, wherein a mixture of TiO 2 with said component having denitration activity is calcined at 300° C. or higher, followed by adding an aqueous solution of said metal sulfate containing water of crystallization and calcining the resulting mixture at 300° C. or higher.
Claim 4
Dependent Claim
24 words
The process for removing nitrogen oxides according to claim 1 wherein the catalyst contacts exhaust gases at a temperature of 200° to 550° C.
Claim 5
Dependent Claim
25 words
The process for removing nitrogen oxides according to claim 1 wherein the metal sulfate containing water of crystallization comprises 5-15% of the catalyst by weight.
Claim 6
Dependent Claim
114 words
A process for removing nitrogen oxides from exhaust gases containing at least nitrogen oxides from volatile metal compounds, the process comprising contacting the exhaust gases in the presence of ammonia at a temperature of 150° to 600° C. with a catalyst containing: TiO 2 ; a component active to a nitrogen oxides-removing reaction selected from the group of metal components comprising Or, Mo, Fe, Co, Ni, Cu and Ce, wherein the atomic ratio of Ti to the metal component ranges from 99:1 to 70:30; and, a metal sulfate containing water of crystallization comprising 4-30% of the catalyst by weight, the metal component of the metal sulfate selected from the group comprising Al and Mn.
Claim 7
Dependent Claim
114 words
A process for removing nitrogen oxides from exhaust gases containing at least nitrogen oxides from volatile metal compounds, the process comprising contacting the exhaust gases in the presence of ammonia at a temperature of 150° to 600° C. with a catalyst containing: TiO 2 ; a component active to a nitrogen oxides-removing reaction selected from the group of metal components comprising Or, Mo, Fe, Co, Ni, Cu and Ce, wherein the atomic ratio of Ti to the metal component ranges from 99:1 to 70:30; and, a metal sulfate containing water of crystallization comprising 4-30% of the catalyst by weight, the metal component of the metal sulfate selected from the group comprising Al and Mn.
Claim 8
Dependent Claim
29 words
The process for removing nitrogen oxides from exhaust gases according to claim 5 wherein the component active to a nitrogen oxides-removing reaction is an oxide or sulfate of V.
Claim 9
Dependent Claim
29 words
The process for removing nitrogen oxides from exhaust gases according to claim 5 wherein the component active to a nitrogen oxides-removing reaction is an oxide or sulfate of W.
Claim 10
Dependent Claim
27 words
The process for removing nitrogen oxides from exhaust gases according to claim 5 wherein the metal component of the metal sulfate containing water of crystallization is Mg.
Claim 11
Dependent Claim
28 words
The process for removing nitrogen oxides from exhaust gases according to claim 5 wherein the metal sulfate containing water of crystallization comprises 5-15% of the catalyst by weight.
Claim 12
Dependent Claim
103 words
A process for removing nitrogen oxides from exhaust gases containing at least nitrogen oxides and volatile metal compounds, the process comprising contacting the exhaust gases in the presence of ammonia with a catalyst containing TiO 2 ; a component active to nitrogen oxides-removing reaction, the component selected from the group comprising oxides or sulfates of metals; and, a metal sulfate hydrate, the metal selected from the group comprising Al, Mg and Mn, wherein the atomic ratio of Ti to the component active to nitrogen oxides-removing reaction ranges from 99:1 to 70:30, and the metal sulfate hydrate comprises 4-30% of the catalyst by weight.
Claim 13
Dependent Claim
103 words
A process for removing nitrogen oxides from exhaust gases containing at least nitrogen oxides and volatile metal compounds, the process comprising contacting the exhaust gases in the presence of ammonia with a catalyst containing TiO 2 ; a component active to nitrogen oxides-removing reaction, the component selected from the group comprising oxides or sulfates of metals; and, a metal sulfate hydrate, the metal selected from the group comprising Al, Mg and Mn, wherein the atomic ratio of Ti to the component active to nitrogen oxides-removing reaction ranges from 99:1 to 70:30, and the metal sulfate hydrate comprises 4-30% of the catalyst by weight.
Claim 14
Dependent Claim
26 words
The process for removing nitrogen oxides from exhaust gases wherein the component active to nitrogen oxides-removing reaction is an oxide or sulfate of V or W.
Claim 15
Dependent Claim
26 words
The process for removing nitrogen oxides from exhaust gases wherein the component active to nitrogen oxides-removing reaction is an oxide or sulfate of V or W.
Claim 16
Dependent Claim
35 words
The process for removing nitrogen oxides from exhaust gases according to claim 10 wherein the component active to nitrogen oxides-removing reaction is an oxide or sulfate of Cr, Mo, Fe, Co, Ni, Cu or Ce.
References Cited (Backward Citations)
US4378338A
Cited
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1992-09-11 | 1993-03-13 | 1993-09-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-09-11 | 1997-03-13 | 1997-09-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-09-11 | 2001-03-13 | 2001-09-12 | $7700.00 | Window Closed / Lapsed |