Claims
- 1. 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.
- 2. 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.
Parent Case Info
This application is a division of application Ser. No. 07/292,231, filed on Dec. 30, 1988, now U.S. Pat. No. 5,108,977.
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Divisions (1)
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Number |
Date |
Country |
Parent |
292231 |
Dec 1988 |
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