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US4016241A
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Process for reducing nitrogen oxides from flue gas
Assignee: Tonen General Sekiyu KK
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Filing: 1975-09-16
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Granted: 1977-04-05
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Expires: 1995-09-16
Abstract
Abstract Nitrogen oxides are removed from gas mixtures containing nitrogen oxides and oxygen by adding a reducing agent that is a C2 to C6 olefin or an aromatic hydrocarbon such as benzene or toluene, preferably butene-1, and contacting the mixture at 200 DEG to 450 DEG C with a catalyst comprising iridium or a compound thereof supported on a refractory carrier, preferably alumina.
Inventors
- 👤 Eiichiroh Nishikawa
- 👤 Takuji Itoh
- 👤 Setsuo Kamiyama
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 07:29
CPC Classifications
B; B01; B01J; B01J23/00; B01J23/38; B01J23/48; B01D; B01D53/00; B01D53/34; B01D53/74; B01D53/86; B01D53/8621; B01D53/8625; B01D53/8628; B01J23/40; B01J23/46; B01J23/468; B01J23/54; B01J23/56; B01J23/64; B01J23/652; B01J23/70; B01J23/89; B01J23/8926
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
109 words
A process for removing nitrogen oxides from a gas mixture containing nitrogen oxides and oxygen which comprises adding to said gas mixture a reducing agent selected from the group consisting of an olefin of 2 to 6 carbon atoms, benzene and toluene, said reducing agent being added in an amount of up to about 1/20 mole percent based on oxygen in the gas and an amount ranging between about 0.1 and about 20 moles per mole of nitrogen oxide, and contacting said mixture, at a temperature within the range of about 200° to 450° C, with a catalyst comprising iridium or a compound thereof supported on a refractory carrier.
Claim 2
Dependent Claim
109 words
A process for removing nitrogen oxides from a gas mixture containing nitrogen oxides and oxygen which comprises adding to said gas mixture a reducing agent selected from the group consisting of an olefin of 2 to 6 carbon atoms, benzene and toluene, said reducing agent being added in an amount of up to about 1/20 mole percent based on oxygen in the gas and an amount ranging between about 0.1 and about 20 moles per mole of nitrogen oxide, and contacting said mixture, at a temperature within the range of about 200° to 450° C, with a catalyst comprising iridium or a compound thereof supported on a refractory carrier.
Claim 3
Dependent Claim
12 words
A process as defined by claim 1 wherein said carrier comprises alumina.
Claim 4
Dependent Claim
38 words
A process as defined by claim 1 wherein the iridium or iridium compound is present on the carrier in an amount ranging from about 0.001 to about 5% by weight, as the metal, based on the total catalyst.
Claim 5
Dependent Claim
62 words
A process as defined by claim 1 wherein the catalyst includes a co-catalytic component, in an amount ranging from about 0.001 to about 5% by weight, as the metal, based on the total catalyst, wherein the co-catalyst is at least one metal or compound thereof selected from Group IB and Group VIB of the Periodic Table, alkali metals, and alkaline earth metals.
Claim 6
Dependent Claim
13 words
A process as defined by claim 1 wherein the reducing agent comprises butene-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) | 1980-04-04 | 1980-10-04 | 1981-04-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-04-04 | 1984-10-04 | 1985-04-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-04-04 | 1988-10-04 | 1989-04-05 | $7700.00 | Window Closed / Lapsed |