摘要:
An exhaust gas cleaner comprising a heat-resistant, porous filter, a porous ceramic layer formed on the filter, and a catalyst supported by the ceramic layer, the catalyst consisting essentially of:(a) at least one of alkali metal elements;(b) copper and vanadium; and(c) at least one of rare earth elements.By using this exhaust gas cleaner, particulate matter in the exhaust gas is oxidized by the catalyst supported by the filter, and nitrogen oxides are reduced by the particulate matter serving as a reducing agent.
摘要:
An exhaust gas cleaner comprising a heat-resistant, porous filter, a porous ceramic layer formed on the filter, and a catalyst supported by the ceramic layer, the catalyst consisting essentially of:(a) at least one of alkali metal elements;(b) copper and vanadium; and(c) at least one of rare earth elements.By using this exhaust gas cleaner, particulate matter in the exhaust gas is oxidized by the catalyst supported by the filter, and nitrogen oxides are reduced by the particulate matter serving as a reducing agent.
摘要:
The exhaust gas cleaner comprising a heat-resistant, porous body and a catalyst supported by the body for cleaning an exhaust gas containing substantially no fine carbonaceous particles, which is equivalent to an oxidizing atmosphere, the catalyst consisting essentially of (a) one or more alkali metal elements; (b) one or more transition metal elements in Group IB; Group IIB, Group VB, Group VIB, Group VIIB and Group VIII of the Periodic Table (excluding platinum-group elements), and Sn; and (c) one or more rare earth elements. The second catalyst consisting essentially of at least one platinum-group element, may be supported by the heat-resistant, porous body.
摘要:
The method of cleaning an exhaust gas containing nitrogen oxides including disposing an exhaust gas cleaner comprising a heat-resistant, porous body, which may support a catalyst consisting essentially of (a) at least one of alkali metal elements; (b) at least one of elements selected from the group consisting of Cu, Co, Mn and V, (c) at least one of rare earth elements, in a flow path of the exhaust gas, spraying a liquid hydrocarbon into a stream of the exhaust gas on the upstream side of the exhaust gas cleaner, thereby causing atomized and gasified hydrocarbon to function as a reducing agent for reducing the nitrogen oxides in the exhaust gas.
摘要:
An exhaust gas containing nitrogen oxides and particulate matter is cleaned by using an exhaust gas cleaner including a heat-resistant, porous filter; a porous ceramic powder layer formed on the filter; and a catalyst supported by the ceramic powder layer, the catalyst consisting essentially of (a) at least one of alkali metal elements, (b) cobalt and/or manganese, (c) vanadium, and (d) at least one of rare earth elements, whereby the nitrogen oxides are reduced by the particulate matter in the exhaust gas serving as a reducing agent.
摘要:
An exhaust gas containing nitrogen oxides and particulate matter is cleaned by using an exhaust gas cleaner including a heat-resistant, porous filter; a porous ceramic powder layer formed on the filter; and a catalyst supported by the ceramic powder layer, the catalyst consisting essentially of (a) at least one of alkali metal elements, (b) cobalt and/or manganese, (c) vanadium, and (d) at least one of rare earth elements, whereby the nitrogen oxides are reduced by the particulate matter in the exhaust gas serving as a reducing agent.
摘要:
An exhaust gas cleaner being constituted by a first catalyst of a first porous inorganic oxide supporting a silver component in combination with a W component and a second catalyst of a second porous inorganic oxide supporting a Pt component and optionally a W component. The Ag component may include Ag and compounds thereof, the Pt component may include Pt, Pd, Ru, Rh, Ir, and Au, and the W component may include W, V, Mn, Mo, Nb, and Ta. The W component effectively catalyzes the reduction of nitrogen oxides by ammonia to enhance the removal efficiency of the exhaust gas cleaner.
摘要:
The exhaust gas cleaner comprising a heat-resistant, porous body and a catalyst supported by the body for cleaning an exhaust gas containing substantially no fine carbonaceous particles, which is equivalent to an oxidizing atmosphere, the catalyst consisting essentially of (a) one or more alkali metal elements; (b) one or more transition metal elements in Group IB; Group IIB, Group VA, Group VIA, Group VIIA, and Group VIII of the Periodic Table (excluding platinum-group elements), and Sn; and (c) one or more rare earth elements. The second catalyst consisting essentially of at least one platinum-group element, may be supported by the heat-resistant porous body.
摘要:
Nitrogen oxides are efficiently removed frown an exhaust gas containing nitrogen oxides and an excess amount of oxygen, by (i) disposing an exhaust gas cleaner in a flow path of the exhaust gas, the exhaust gas cleaner comprising a first catalyst comprising 0.2-15 weight % (on a metal basis) of silver or silver oxide supported on a porous inorganic oxide on the inlet side and a second catalyst comprising 0.2-15 weight % (on a metal basis) of silver or silver oxide and 2 weight % or less (on a metal basis) of copper or copper oxide supported on a porous inorganic oxide on the outlet side; (ii) introducing hydrocarbons and/or oxygen-containing organic compounds into the exhaust gas on the upstream side of the exhaust gas cleaner; and (iii) bringing the exhaust gas into contact with the exhaust gas cleaner at a temperature of 200.degree.-600.degree. C.
摘要:
Nitrogen oxides are efficiently removed from an exhaust gas containing nitrogen oxides and an excess amount of oxygen, by (i) disposing an exhaust gas cleaner in a flow path of the exhaust gas, the exhaust gas cleaner comprising a first catalyst comprising 0.2-15 weight % (on a metal basis) of at least one silver salt selected from the group consisting of silver halides, silver sulfate and silver phosphate supported on a porous inorganic oxide on an inlet side and a second catalyst comprising (a) 0.2-15 weight % (on a metal basis) of at least one silver salt selected from the group consisting of silver halides, silver sulfate and silver phosphate and (b) up to 2 weight % (on a metal basis) of copper or copper oxide supported on a porous inorganic oxide on an outlet side; (ii) introducing at least one reducing agent selected from hydrocarbons and oxygen-containing organic compounds into the exhaust gas on an upstream side of the exhaust gas cleaner; and (iii) bringing the exhaust gas into contact with the exhaust gas cleaner at a temperature of 200.degree.-600.degree. C.