US3961020A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for removing sulfur oxides and nitrogen oxides from flue gases using halogen-impregnated actuated carbon with simultaneous injection of ammonia
Assignee: Hitachi Ltd
•
Filing: 1973-10-05
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Granted: 1976-06-01
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Expires: 1993-10-05
Abstract
Abstract Carbonaceous materials are impregnated with bromine, chlorine, iodine or their compounds, and brought in contact with a flue gas in the presence of ammonia, whereby nitrogen oxides and sulfur oxides contained in the flue gas are trapped by the carbonaceous materials and can be removed from the flue gas with a very high percent removal.
Inventors
- 👤 Michiharu Seki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 12:02
CPC Classifications
F; F01; F01N; F01N3/00; F01N3/08; F01N3/0807; F01N3/0828; F01N3/0842; B; B01; B01D; B01D53/00; B01D53/02; B01D53/34; B01D53/46; B01D53/54; B01D53/56; B01D53/60; F01N3/10; F01N3/18; F01N3/20; F01N3/206; F01N2370/00; F01N2370/40; F01N2610/00; F01N2610/02; F01N2610/06; Y; Y02; Y02A; Y02A50/00; Y02A50/20
Claims Analysis
Total Claims: 32
Claim 1
Independent Claim
208 words
A process for removing at least one nitrogen oxide or sulfur oxide from a flue gas comprising contacting the flue gas in the presence of oxygen with a bed of carbonaceous material selected from the group consisting of activated carbon, graphite, carbonized char and amorphous carbon, said carbonaceous material being impregnated with a halogen or halogen compound selected from the group consisting of iodine, bromine, chlorine, ammonium iodide, ammonium bromide, ammonium chloride, hydrogen iodide, hydrogen bromide and hydrogen chloride, said bed containing at least 0.01 gram of said halogen or at least 0.01 gram of said halogen compound measured in terms of the halogen content of said halogen compound per kilogram of said carbonaceous material, said flue gas being contacted with said bed at a temperature at which the ammonium salt of said halogen or the ammonium salt of the halogen component of said halogen compound can be adsorbed by said carbonaceous material, and simultaneously feeding to said bed ammonia or a compound capable of liberating ammonia at the temperature at which the flue gas contacts said bed so that ammonia contacts said carbonaceous material as said flue gas contacts said carbonaceous material, thereby removing said at least one nitrogen oxide or sulfur oxide from said flue gas.
Claim 2
Dependent Claim
208 words
A process for removing at least one nitrogen oxide or sulfur oxide from a flue gas comprising contacting the flue gas in the presence of oxygen with a bed of carbonaceous material selected from the group consisting of activated carbon, graphite, carbonized char and amorphous carbon, said carbonaceous material being impregnated with a halogen or halogen compound selected from the group consisting of iodine, bromine, chlorine, ammonium iodide, ammonium bromide, ammonium chloride, hydrogen iodide, hydrogen bromide and hydrogen chloride, said bed containing at least 0.01 gram of said halogen or at least 0.01 gram of said halogen compound measured in terms of the halogen content of said halogen compound per kilogram of said carbonaceous material, said flue gas being contacted with said bed at a temperature at which the ammonium salt of said halogen or the ammonium salt of the halogen component of said halogen compound can be adsorbed by said carbonaceous material, and simultaneously feeding to said bed ammonia or a compound capable of liberating ammonia at the temperature at which the flue gas contacts said bed so that ammonia contacts said carbonaceous material as said flue gas contacts said carbonaceous material, thereby removing said at least one nitrogen oxide or sulfur oxide from said flue gas.
Claim 3
Dependent Claim
23 words
A process according to claim 1, wherein the contact with the flue gas is carried out at a temperature of 60° to 150°C.
Claim 4
Dependent Claim
20 words
The process of claim 1, wherein gaseous ammonia is fed to said bed from a source external of the bed.
Claim 5
Dependent Claim
39 words
The process of claim 3, wherein the amount of ammonia fed to said bed is approximately equivalent to or in slight excess of the amount of said at least one nitrogen oxide or sulfur oxide on a molar basis.
Claim 6
Dependent Claim
38 words
The process of claim 4, wherein the amount of ammonia fed to said bed is approximately equivalent to the amount of said at least one nitrogen oxide or sulfur oxide fed to said bed on a molar basis.
Claim 7
Dependent Claim
45 words
The process of claim 1, wherein the amount of ammonia or compound capable of liberating ammonia fed to said bed is approximately equivalent to or in slight excess of the amount of said at least one nitrogen oxide or sulfur oxide on a molar basis.
Claim 8
Dependent Claim
19 words
The process of claim 1, wherein an aqueous solution of ammonia or ammonium carbonate is fed to said bed.
Claim 9
Dependent Claim
49 words
The process of claim 1, wherein said bed of carbonaceous material is non-fluidized contained in a housing provided with means for moving said bed with respect to said housing in a first direction, said flue gas being passed through said bed in a direction opposite to said first direction.
Claim 10
Dependent Claim
15 words
The process of claim 1, wherein said flue gas contains at least one nitrogen oxide.
Claim 11
Dependent Claim
20 words
The process of claim 1, wherein said flue gas contains at least nitrogen oxide and at least one sulfur oxide.
Claim 12
Dependent Claim
194 words
A process for removing at least one nitrogen oxide or sulfur from a flue gas comprising contacting the flue gas in the presence of oxygen with a bed of a carbonaceous material selected from the group consisting of activated carbon graphite, carbonized char and amorphous carbon, said carbonaceous material being impregnated with bromine, iodine, chlorine, an ammonium salt thereof, or a compound capable of liberating chlorine, bromine, iodine or an ammonium salt thereof under the conditions encountered when said flue gas contacts said bed and simultaneously feeding to said bed of carbonaceous material ammonia or a compound capable of liberating ammonia at the temperature at which the flue gas contacts said bed, thereby removing at least one nitrogen oxide or sulfur oxide from said flue gas, said bed containing at least 0.01 gram bromine, iodine or chlorine per kilogram of said carbonaceous material or a corresponding amount of said ammonium salt or said compound capable of yielding chlorine, bromine, iodine or an ammonium salt thereof, said flue gas being contacted with said bed at a temperature such that the ammonium salt of said bromine, iodine or chlorine can be adsorbed by said carbonaceous material.
Claim 13
Dependent Claim
194 words
A process for removing at least one nitrogen oxide or sulfur from a flue gas comprising contacting the flue gas in the presence of oxygen with a bed of a carbonaceous material selected from the group consisting of activated carbon graphite, carbonized char and amorphous carbon, said carbonaceous material being impregnated with bromine, iodine, chlorine, an ammonium salt thereof, or a compound capable of liberating chlorine, bromine, iodine or an ammonium salt thereof under the conditions encountered when said flue gas contacts said bed and simultaneously feeding to said bed of carbonaceous material ammonia or a compound capable of liberating ammonia at the temperature at which the flue gas contacts said bed, thereby removing at least one nitrogen oxide or sulfur oxide from said flue gas, said bed containing at least 0.01 gram bromine, iodine or chlorine per kilogram of said carbonaceous material or a corresponding amount of said ammonium salt or said compound capable of yielding chlorine, bromine, iodine or an ammonium salt thereof, said flue gas being contacted with said bed at a temperature such that the ammonium salt of said bromine, iodine or chlorine can be adsorbed by said carbonaceous material.
Claim 14
Dependent Claim
20 words
The process of claim 11, wherein said ammonia is fed to said bed from a source external of said bed.
Claim 15
Dependent Claim
39 words
The process of claim 12, wherein the amount of ammonia fed to said bed is approximately equivalent to or in slight excess of the amount of said at least one nitrogen oxide or sulfur oxide on a molar basis.
Claim 16
Dependent Claim
19 words
The process of claim 11, wherein an aqueous solution of ammonia or ammonium carbonate is fed to said bed.
Claim 17
Dependent Claim
23 words
The process of claim 12, wherein said flue gas is contacted with said carbonaceous material at a temperature of about 60° to 150°C.
Claim 18
Dependent Claim
47 words
The process of claim 12, wherein said carbonaceous material contains a sufficient amount of a compound capable of yielding bromine, iodine or chlorine so that the amount of bromine, iodine or chlorine yielded by said compound is at least about 0.01 g. per kg. of cabonaceous material.
Claim 19
Dependent Claim
15 words
The process of claim 11, wherein said flue gas contains at least one nitrogen oxide.
Claim 20
Dependent Claim
20 words
The process of claim 11, wherein said flue gas contains at least nitrogen oxide and at least one sulfur oxide.
Claim 21
Dependent Claim
19 words
The process of claim 11, wherein said carbonaceous material is impregnated with ammonium bromide, ammonium iodide or ammonium chloride.
Claim 22
Dependent Claim
14 words
The process of claim 19, wherein said carbonaceous material is impregnated with ammonium iodide.
Claim 23
Dependent Claim
23 words
The process of claim 11, wherein said flue gas is contacted with said cabonaceous material at a temperature of about 60° to 150°C.
Claim 24
Dependent Claim
93 words
A process for removing at least one nitrogen oxide or sulfur oxide from a flue gas comprising: A. passing said flue gas through a bed of carbonaceous material containing ammonium iodide, ammonium bromide or ammonium chloride so that (1) said at least one nitrogen oxide or sulfur oxide is retained in said bed in the form of an ammonium salt and (2) iodine, bromine, or chlorine as a by-product is produced in said bed, and B. feeding simultaneously ammonia to said bed to convert said by-product to an ammonium salt in said bed.
Claim 25
Dependent Claim
93 words
A process for removing at least one nitrogen oxide or sulfur oxide from a flue gas comprising: A. passing said flue gas through a bed of carbonaceous material containing ammonium iodide, ammonium bromide or ammonium chloride so that (1) said at least one nitrogen oxide or sulfur oxide is retained in said bed in the form of an ammonium salt and (2) iodine, bromine, or chlorine as a by-product is produced in said bed, and B. feeding simultaneously ammonia to said bed to convert said by-product to an ammonium salt in said bed.
Claim 26
Dependent Claim
18 words
The process of claim 22, wherein flue gas is contacted with a plurality of beds arranged in series.
Claim 27
Dependent Claim
14 words
The process of claim 23, further comprising regenerating at least one of the beds.
Claim 28
Dependent Claim
144 words
A process for removing at least one nitrogen oxide or sulfur oxide from a flue gas comprising contacting the flue gas in the presence of oxygen with a bed of activated carbon impregnated with bromine, iodine, chlorine, an ammonium salt thereof, or a compound capable of liberating bromine, iodine, chlorine, or an ammonium salt thereof under the conditions encountered when said flue gas contacts said bed, and simultaneously feeding to said bed ammonia or a compound capable of liberating ammonia at the temperature at which the flue gas contacts said bed, thereby removing at least one nitrogen oxide or sulfur oxide from said flue gas, said bed containing at least 0.01 gram bromine, iodine or chlorine per kilogram of said activated carbon or a corresponding amount of said ammonium salt or said compound capable of yielding chlorine, bromine, iodine or an ammonium salt thereof.
Claim 29
Dependent Claim
144 words
A process for removing at least one nitrogen oxide or sulfur oxide from a flue gas comprising contacting the flue gas in the presence of oxygen with a bed of activated carbon impregnated with bromine, iodine, chlorine, an ammonium salt thereof, or a compound capable of liberating bromine, iodine, chlorine, or an ammonium salt thereof under the conditions encountered when said flue gas contacts said bed, and simultaneously feeding to said bed ammonia or a compound capable of liberating ammonia at the temperature at which the flue gas contacts said bed, thereby removing at least one nitrogen oxide or sulfur oxide from said flue gas, said bed containing at least 0.01 gram bromine, iodine or chlorine per kilogram of said activated carbon or a corresponding amount of said ammonium salt or said compound capable of yielding chlorine, bromine, iodine or an ammonium salt thereof.
Claim 30
Dependent Claim
20 words
The process of claim 25, wherein gaseous ammonia is fed to said bed from a source external of said bed.
Claim 31
Dependent Claim
19 words
The process of claim 25, wherein an aqueous solution of ammonia or ammonium carbonate is fed to said bed.
Claim 32
Dependent Claim
23 words
The process of claim 25, wherein said flue gas is contacted with said carbonaceous material at a temperature of about 60° to 150°C.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-06-01 | 1979-12-01 | 1980-06-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-06-01 | 1983-12-01 | 1984-06-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-06-01 | 1987-12-01 | 1988-06-01 | $7700.00 | Window Closed / Lapsed |