US5154901A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of cleaning an exhaust gas containing nitrogen oxides and fine carbon-containing particulates
Assignee: Riken Corp
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Filing: 1991-09-06
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Granted: 1992-10-13
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Expires: 2011-09-06
Abstract
Abstract An exhaust gas cleaner comprising a catalyst carried on a heat-resistant ter, the catalyst comprising (a) one or more alkali metals, (b) one or more metals selected from the group consisting of Zn, Sn and transition metals excluding platinum-group metals, and (c) one or more rare earth metals, and a method of cleaning an exhaust gas with it. Alkali metals may be added to a fuel.
Inventors
- 👤 Kiyohide Yoshida
- 👤 Satoshi Sumiya
- 👤 Takashi Ibusuki
- 👤 Akira Obuchi
- 👤 Hyogoro Aoyama
- 👤 Akihiko Ohi
- 👤 Hideo Ohuchi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 21:15
CPC Classifications
B; B01; B01D; B01D53/00; B01D53/34; B01D53/92; B01D53/94; B01D53/9445; B01D53/945; B01D53/74; B01D53/86; B01D53/8603; B01D53/8609; B01J; B01J23/00; B01J23/02; B01J23/04; B01J23/16; B01J23/32; B01J23/34; B01J23/70; B01J23/76; B01J23/78; B01J23/83; B01J23/84; B01J23/889; B01J23/8892; B01J37/00; B01J37/02; B01J37/0215; B01J21/00; B01J21/06; B01J21/063; Y; Y02; Y02T; Y02T10/00; Y02T10/10; Y02T10/12
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
126 words
A method of cleaning an exhaust gas containing nitrogen oxides and fine carbon-containing particulate material, comprising passing said exhaust gas through an exhaust gas cleaner comprising a catalyst carried via fine ceramic powder on a heat-resistant filter, said catalyst comprising (a) 0.1-20 weight % of one or more alkali metals, (b) 0.1-20 weight % of one or more metals selected from the group consisting of Zn, Sn and transition metals excluding platinum-group metals, and (c) 0.1-10 weight % of one or more rare earth metals, based on the total weight of metal components and said fine ceramic powder coated on the heat-resistant filter, wherein the fine carbon-containing particulate material in said exhaust gas acts as a reducing agent for reducing nitrogen oxides in said exhaust gas.
Claim 2
Independent Claim
126 words
A method of cleaning an exhaust gas containing nitrogen oxides and fine carbon-containing particulate material, comprising passing said exhaust gas through an exhaust gas cleaner comprising a catalyst carried via fine ceramic powder on a heat-resistant filter, said catalyst comprising (a) 0.1-20 weight % of one or more alkali metals, (b) 0.1-20 weight % of one or more metals selected from the group consisting of Zn, Sn and transition metals excluding platinum-group metals, and (c) 0.1-10 weight % of one or more rare earth metals, based on the total weight of metal components and said fine ceramic powder coated on the heat-resistant filter, wherein the fine carbon-containing particulate material in said exhaust gas acts as a reducing agent for reducing nitrogen oxides in said exhaust gas.
Claim 3
Independent Claim
139 words
A method of cleaning an exhaust gas containing nitrogen oxides and fine carbon-containing particle materials formed by combustion of a fuel, comprising adding 0.1-20 weight % of one or more alkali metals to the fuel prior to combustion, and passing said exhaust gas through an exhaust gas cleaner comprising a catalyst carried via fine ceramic powder on a heat-resistant filter, said catalyst comprising (a) 0.1-20 weight % of one or more metals selected from the group consisting of Zn, Sn and transition metals excluding platinum-group metals, and (b) 0.1-10 weight % of one or more rare earth metals, based on the total weight of metal components and said fine ceramic powder coated on the heat-resistant filter, wherein the fine carbon-containing particulate materials in said exhaust gas acts as a reducing agent for reducing nitrogen oxides in said exhaust gas.
Claim 4
Independent Claim
139 words
A method of cleaning an exhaust gas containing nitrogen oxides and fine carbon-containing particle materials formed by combustion of a fuel, comprising adding 0.1-20 weight % of one or more alkali metals to the fuel prior to combustion, and passing said exhaust gas through an exhaust gas cleaner comprising a catalyst carried via fine ceramic powder on a heat-resistant filter, said catalyst comprising (a) 0.1-20 weight % of one or more metals selected from the group consisting of Zn, Sn and transition metals excluding platinum-group metals, and (b) 0.1-10 weight % of one or more rare earth metals, based on the total weight of metal components and said fine ceramic powder coated on the heat-resistant filter, wherein the fine carbon-containing particulate materials in said exhaust gas acts as a reducing agent for reducing nitrogen oxides in said exhaust gas.
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) | 1995-10-13 | 1996-04-13 | 1996-10-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-10-13 | 2000-04-13 | 2000-10-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-10-13 | 2004-04-13 | 2004-10-13 | $7700.00 | Window Closed / Lapsed |