Patent US4031185A successfully refreshed from Google Patents.
US4031185A
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Process for making nitrogen oxides contained in flue gas harmless
Assignee: Hitachi Ltd
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Filing: 1976-01-30
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Granted: 1977-06-21
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Expires: 1996-01-30
Abstract
Abstract The present invention relates to a process for removing nitrogen oxides contained in a gaseous mixture such as combustion flue gas, etc. by reduction of the nitrogen oxides with ammonia, and a cuprous or cupric halide is used as a catalyst to carry out the reduction in a low temperature range. As a result, nitrogen oxides can be satisfactorily removed by the reduction even at about 150 DEG C.
Inventors
- 👤 Hidetoshi Akimoto
- 👤 Ryuichi Kaji
- 👤 Hideo Kikuchi
- 👤 Yukio Hishinuma
- 👤 Yoshijiro Arikawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 18:25
CPC Classifications
B; B01; B01D; B01D53/00; B01D53/34; B01D53/74; B01D53/86; B01D53/8621; B01D53/8625; B01D53/8628
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
58 words
A process for removing nitrogen oxides in a flue gas by conversion to nitrogen and water comprising adding ammonia gas to a flue gas containing nitrogen oxides and passing the resulting mixed gas over a catalyst of cuprous or cupric halide selected from the group consisting of cuprous chloride, cuprous bromide, cupric chloride, cupric bromide, and cupric iodide.
Claim 2
Dependent Claim
58 words
A process for removing nitrogen oxides in a flue gas by conversion to nitrogen and water comprising adding ammonia gas to a flue gas containing nitrogen oxides and passing the resulting mixed gas over a catalyst of cuprous or cupric halide selected from the group consisting of cuprous chloride, cuprous bromide, cupric chloride, cupric bromide, and cupric iodide.
Claim 3
Dependent Claim
63 words
A process for removing nitrogen oxides in a flue gas by conversion to nitrogen and water comprising adding ammonia gas to a flue gas containing nitrogen oxides and passing the resulting mixed gas over a catalyst of cuprous or cupric halide selected from the group consisting of cuprous chloride, cuprous bromide, cupric chloride, cupric bromide, and cupric iodide in the presence of oxygen.
Claim 4
Dependent Claim
63 words
A process for removing nitrogen oxides in a flue gas by conversion to nitrogen and water comprising adding ammonia gas to a flue gas containing nitrogen oxides and passing the resulting mixed gas over a catalyst of cuprous or cupric halide selected from the group consisting of cuprous chloride, cuprous bromide, cupric chloride, cupric bromide, and cupric iodide in the presence of oxygen.
Claim 5
Dependent Claim
21 words
A process according to claim 1, wherein the catalyst contains an ammonium salt in addition to the cuprous or cupric halide.
Claim 6
Dependent Claim
24 words
A process according to claim 1, wherein the catalyst contains a vanadium compound or molybdenum compound in addition to the cuprous or cupric halide.
Claim 7
Dependent Claim
26 words
A process according to claim 3, wherein the catalyst contains an alkali metal halide in addition to the cuprous or cupric halide and the ammonium salt.
Claim 8
Dependent Claim
28 words
A process according to claim 1, wherein the cuprous or cupric halide is adsorbed on a porous carrier selected from silica gel, silica-alumina gel, alumina, or activated carbon.
Claim 9
Dependent Claim
12 words
A process according to claim 1, wherein said catalyst is cuprous chloride.
Claim 10
Dependent Claim
12 words
A process according to claim 1, wherein said catalyst is cupric chloride.
Claim 11
Dependent Claim
12 words
A process according to claim 2, wherein said catalyst is cuprous chloride.
Claim 12
Dependent Claim
12 words
A process according to claim 2, wherein said catalyst is cupric chloride.
Claim 13
Dependent Claim
23 words
A process according to claim 1, wherein said mixed gas is passed over said catalyst at a temperature of 100° C or higher.
Claim 14
Dependent Claim
26 words
A process according to claim 11, wherein said mixed gas is passed over said catalyst at a temperature in the range of 100° to 150° C.
Claim 15
Dependent Claim
23 words
A process according to claim 2, wherein said mixed gas is passed over said catalyst at a temperature of 100° C or higher.
Claim 16
Dependent Claim
26 words
A process according to claim 13, wherein said mixed gas is passed over said catalyst at a temperature in the range of 100° to 150° C.
Claim 17
Dependent Claim
16 words
A process according to claim 3, wherein said ammonium salt is ammonium chloride or ammonium sulfate.
Claim 18
Dependent Claim
23 words
A process according to claim 4, wherein said vanadium compound is selected from the group consisting of vanadium oxides, vanadium oxyhalides, and metavanadates.
Claim 19
Dependent Claim
12 words
A process according to claim 16, wherein said metavanadate is ammonium metavanadate.
Claim 20
Dependent Claim
26 words
A process according to claim 4, wherein said molybdenum compound is selected from the group consisting of molybdenum oxides, molybdenum halides, molybdenum oxyhalides and ammonium molybdate.
Claim 21
Dependent Claim
13 words
A process according to claim 18, wherein said molybdenum compound is ammonium molybdate.
Claim 22
Dependent Claim
14 words
A process according to claim 5, wherein said alkali metal halide is sodium chloride.
References Cited (Backward Citations)
BE804317A
Cited
JPS4948590A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-06-20 | 1980-12-20 | 1981-06-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-06-20 | 1984-12-20 | 1985-06-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-06-20 | 1988-12-20 | 1989-06-21 | $7700.00 | Window Closed / Lapsed |