Patent US4199554A successfully refreshed from Google Patents.
US4199554A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of and apparatus for removing nitrogen oxides from the gases containing nitrogen oxides
Assignee: Kureha Corp
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Filing: 1977-12-30
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Granted: 1980-04-22
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Expires: 1997-12-30
Abstract
Abstract Disclosed herein is a method of removing the nitrogen oxides from the gases containing nitrogen oxides by contacting any such gas with ammonia at a temperature of from 100° C. to 230° C. in the presence of a catalyst so that a reaction takes place between the nitrogen oxides and ammonia. This reaction is conducted in such a manner as to prevent the by-produced ammonium nitrate from depositing on the catalyst. There is also disclosed a specific apparatus for practicing the method.
Inventors
- 👤 Tadashi Araki
- 👤 Hatsuo Seito
- 👤 Masayuki Funabashi
- 👤 Ritaro Saito
- 👤 Koji Seguchi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 14:53
CPC Classifications
B; B01; B01D; B01D53/00; B01D53/34; B01D53/74; B01D53/86; B01D53/8621; B01D53/8625; Y; Y10; Y10S; Y10S502/00; Y10S502/515
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
87 words
A method for the conversion of nitrogen oxide to ammonia in the presence of a catalyst to facilitate said conversion in the catalyst system while minimizing deposition of ammonium nitrate deposition on said catalyst which comprises passing said nitrogen oxides through a system containing said catalyst at a temperature of from 100° to 230° C., and intermittently introducing into said system a sufficient amount of a substance capable of decomposing ammonium nitrate formed in said system, whereby the deposition of ammonium nitrate on said catalyst is minimized.
Claim 2
Independent Claim
87 words
A method for the conversion of nitrogen oxide to ammonia in the presence of a catalyst to facilitate said conversion in the catalyst system while minimizing deposition of ammonium nitrate deposition on said catalyst which comprises passing said nitrogen oxides through a system containing said catalyst at a temperature of from 100° to 230° C., and intermittently introducing into said system a sufficient amount of a substance capable of decomposing ammonium nitrate formed in said system, whereby the deposition of ammonium nitrate on said catalyst is minimized.
Claim 3
Dependent Claim
80 words
The method according to claim 1, wherein said substance capable of decomposing ammonium nitrate is an alcohol with carbon number of 1 to 4, a carboxylic acid with carbon number of 1 to 4, an aldehyde with carbon number of 1 to 4, a ketone with carbon number of 3 to 4, an oxide with carbon number of 2 to 4, an ester with carbon number of 2 to 4, or an ether with carbon number of 2 to 4.
Claim 4
Dependent Claim
15 words
The method according to claim 2, wherein said alcohol is methanol, ethanol, propanol or butanol.
Claim 5
Dependent Claim
20 words
The method according to claim 2, wherein said carboxylic acid is formic acid, acetic acid, propionic acid or butyric acid.
Claim 6
Dependent Claim
15 words
The method according to claim 2, wherein said aldehyde is formalin, acetoaldehyde or butyl aldehyde.
Claim 7
Dependent Claim
15 words
The method according to claim 2, wherein said ketone is acetone, or methyl ethyl ketone.
Claim 8
Dependent Claim
17 words
The method according to claim 2, wherein said oxide is ethylene oxide, propylene oxide or butylene oxide.
Claim 9
Dependent Claim
23 words
The method according to claim 2, wherein said ester is methyl formate, ethyl formate, methyl acetate, ethyl acetate, vinyl acetate or methyl propionate.
Claim 10
Dependent Claim
18 words
The method according to claim 2, wherein said ether is dimethyl ether, methyl ethyl ether, or diethyl ether.
Claim 11
Dependent Claim
18 words
A method of claim 1, wherein said substance is added to said system concurrently with said nitrogen oxides.
Claim 12
Dependent Claim
14 words
A method of claim 1, wherein said substance is added to said system intermittently.
Claim 13
Independent Claim
96 words
A method for the conversion of nitrogen oxide to ammonia in the presence of a catalyst to facilitate said conversion while minimizing deposition of ammonium nitrate deposition on said catalyst which comprises passing said nitrogen oxides through a system containing said catalyst at a temperature of from 100° to 230° C., periodically halting said passing of nitrogen oxides and during the period of halting said passing introducing into said system a sufficient amount of a substance capable of decomposing ammonium nitrate formed in said system, whereby the deposition of ammonium nitrate on said catalyst is minimized.
Claim 14
Independent Claim
96 words
A method for the conversion of nitrogen oxide to ammonia in the presence of a catalyst to facilitate said conversion while minimizing deposition of ammonium nitrate deposition on said catalyst which comprises passing said nitrogen oxides through a system containing said catalyst at a temperature of from 100° to 230° C., periodically halting said passing of nitrogen oxides and during the period of halting said passing introducing into said system a sufficient amount of a substance capable of decomposing ammonium nitrate formed in said system, whereby the deposition of ammonium nitrate on said catalyst is minimized.
Claim 15
Dependent Claim
22 words
The method according to claim 12, wherein said substance capable of decomposing ammonium nitrate is an oxygen-containing derivative of a lower hydrocarbon.
Claim 16
Dependent Claim
76 words
The method according to claim 13, wherein said oxygen-containing derivative is an alcohol with carbon number of 1 to 4, a carboxylic acid with carbon number of 1 to 4, an aldehyde with carbon number of 1 to 4, a ketone with carbon number of 3 to 4, an oxide with carbon number of 2 to 4, an ester with carbon number of 2 to 4, or an ether with carbon number of 2 to 4.
Claim 17
Dependent Claim
15 words
The method according to claim 14, wherein said alcohol is methanol, ethanol, propanol or butanol.
Claim 18
Dependent Claim
20 words
The method according to claim 14, wherein said carboxylic acid is formic acid, acetic acid, propionic acid or butyric acid.
Claim 19
Dependent Claim
16 words
The method according to claim 14, wherein said aldehyde is formalin, acetoaldehyde, propionaldehyde or butyl aldehyde.
Claim 20
Dependent Claim
15 words
The method according to claim 14, wherein said ketone is acetone or methyl ethyl ketone.
Claim 21
Dependent Claim
17 words
The method according to claim 14, wherein said oxide is ethylene oxide, propylene oxide or butylene oxide.
Claim 22
Dependent Claim
23 words
The method according to claim 14, wherein said ester is methyl formate, ethyl formate, methyl acetate, ethyl acetate, vinyl acetate or methyl propionate.
Claim 23
Dependent Claim
18 words
The method according to claim 14, wherein said ether is dimethyl ether, methyl ethyl ether or diethyl ether.
Claim 24
Dependent Claim
84 words
The method according to claim 12, wherein said substance capable of decomposing ammonium nitrate is a combustion gas produced from combustion of a light-duty fuel; steam; carbon monoxide; a lower hydrocarbon; or a gas containing methanol, ethanol, propanol, butanol, formic acid, acetic acid, propionic acid, butyric acid, formalin, acetoaldehyde, propionaldehyde, butyl aldehyde, acetone, methyl ethyl ketone, diethyl ketone, ethylene oxide, propylene oxide, butylene oxide, methyl formate, ethyl formate, methyl acetate, ethyl acetate, vinyl acetate, methyl propionate, dimethyl ether, methyl ethyl ether or diethyl ether.
Claim 25
Dependent Claim
18 words
The method according to claim 22, wherein said light-duty fuel is a gaseous fuel, naphtha, kerosine or alcohol.
Claim 26
Dependent Claim
17 words
The method according to claim 22, wherein said lower hydrocarbon is methane, ethane, propane, ethylene or propylene.
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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) | 1983-04-22 | 1983-10-22 | 1984-04-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-04-22 | 1987-10-22 | 1988-04-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-04-22 | 1991-10-22 | 1992-04-22 | $7700.00 | Window Closed / Lapsed |