Abstract: An internal combustion engine, including at least one exhaust-gas line having at least one device for the after-treatment of the exhaust gas and at least one urea-water solution tank, whereby the urea-water solution tank 3 is located close to the engine, is provided.

Abstract: A device and a method for reducing carbon monoxide, hydrocarbons, nitrogen oxides and soot particles present in the exhaust gases of diesel engines are provided. The device includes 1) a diesel oxidation catalyst for the oxidation of carbon monoxide, hydrocarbons and nitrogen monoxide; 2) a first unit by means of which ammonia and/or a compound that breaks down to form ammonia can be metered into the exhaust gas that is to be purified; 3) a catalytically activated particulate filter, containing a wall-flow filter substrate comprising a catalytically active material that promotes the selective catalytic reduction of nitrogen oxides to form nitrogen; 4) a second unit by means of which ammonia and/or a compound that breaks down to form ammonia can be metered into the exhaust gas that is to be purified; as well as 5) a catalyst for the selective catalytic reduction of nitrogen oxides to form nitrogen.

Abstract: An internal combustion engine, including at least one exhaust-gas line having at least one device for the after-treatment of the exhaust gas and at least one urea-water solution tank, whereby the urea-water solution tank 3 is located close to the engine, is provided.

Abstract: An internal combustion engine, including at least one exhaust-gas line having at least one device for the after-treatment of the exhaust gas and at least one urea-water solution tank, whereby the urea-water solution tank 3 is located close to the engine, is provided.

Abstract: A method in which the exhaust gas that is to be purified is passed through an exhaust-gas line containing a diesel oxidation catalyst (DOC) for the oxidation of residual gaseous hydrocarbons (HC) and carbon monoxide (CO) in order to form carbon dioxide (CO2) and for the at least proportional oxidation of the nitrogen monoxide (NO) contained in the exhaust gas in order to form nitrogen dioxide (NO2) is provided.

Abstract: A method is described for reducing the nitrogen oxide levels in diesel engine exhaust gases with the aid of an exhaust gas treatment system, which includes a device for feeding ammonia and/or a compound decomposing to form ammonia, and two SCR units. An ammonia sensor is situated between the first and second SCR unit. A nitrogen oxide sensor is located in the exhaust pipe downstream from the second SCR unit. The signals of the ammonia sensor and the NOx sensor are combined in a defined manner to form the actual value of a virtual NOx/NH3 sensor, which is used as the input variable for a PI or PID controller, which regulates the quantity of reducing agent to be fed into the exhaust gas as needed.

Abstract: A device and a method for reducing carbon monoxide, hydrocarbons, nitrogen oxides and soot particles present in the exhaust gases of diesel engines are provided. The device includes 1) a diesel oxidation catalyst for the oxidation of carbon monoxide, hydrocarbons and nitrogen monoxide; 2) a first unit by means of which ammonia and/or a compound that breaks down to form ammonia can be metered into the exhaust gas that is to be purified; 3) a catalytically activated particulate filter, containing a wall-flow filter substrate comprising a catalytically active material that promotes the selective catalytic reduction of nitrogen oxides to form nitrogen; 4) a second unit by means of which ammonia and/or a compound that breaks down to form ammonia can be metered into the exhaust gas that is to be purified; as well as 5) a catalyst for the selective catalytic reduction of nitrogen oxides to form nitrogen.

Abstract: An internal combustion engine, including at least one exhaust-gas line having at least one device for the after-treatment of the exhaust gas and at least one urea-water solution tank, whereby the urea-water solution tank 3 is located close to the engine, is provided.

Abstract: A method in which the exhaust gas that is to be purified is passed through an exhaust-gas line containing a diesel oxidation catalyst (DOC) for the oxidation of residual gaseous hydrocarbons (HC) and carbon monoxide (CO) in order to form carbon dioxide (CO2) and for the at least proportional oxidation of the nitrogen monoxide (NO) contained in the exhaust gas in order to form nitrogen dioxide (NO2) is provided.

Abstract: An exhaust gas aftertreatment system, in particular for V-type diesel engines, is provided. The system includes, disposed in the exhaust line of the engine in the direction of the exhaust gas flow, a first SCR stage, a catalytically activated particulate filter (cDPF), a second SCR stage, and an ammonia slip catalyst (ASC). A method for purifying diesel engine exhaust gases containing hydrocarbons, carbon monoxide, soot particles, and nitrogen oxides consisting of NO and NO2 is also provided.

Abstract: An exhaust gas aftertreatment system, in particular for V-type diesel engines, is provided. The system includes, disposed in the exhaust line of the engine in the direction of the exhaust gas flow, a first SCR stage, a catalytically activated particulate filter (cDPF), a second SCR stage, and an ammonia slip catalyst (ASC). A method for purifying diesel engine exhaust gases containing hydrocarbons, carbon monoxide, soot particles, and nitrogen oxides consisting of NO and NO2 is also provided.

Abstract: A method is described for reducing the nitrogen oxide levels in diesel engine exhaust gases with the aid of an exhaust gas treatment system, which includes a device for feeding ammonia and/or a compound decomposing to form ammonia, and two SCR units. An ammonia sensor is situated between the first and second SCR unit. A nitrogen oxide sensor is located in the exhaust pipe downstream from the second SCR unit. The signals of the ammonia sensor and the NOx sensor are combined in a defined manner to form the actual value of a virtual NOx/NH3 sensor, which is used as the input variable for a PI or PID controller, which regulates the quantity of reducing agent to be fed into the exhaust gas as needed.

Abstract: Nitrogen oxide storage catalysts are used to remove the nitrogen oxides present in the lean exhaust gas of lean-burn engines. As a result of the stress due to high temperatures in vehicle operation, they are subject to thermal aging processes which affect both the nitrogen oxide storage components and the noble metals present as catalytically active components. The present invention provides a process with which the catalytic activity of a nitrogen oxide storage catalyst which comprises, in addition to platinum as a catalytically active component, basic compounds of strontium and/or barium on a support material comprising cerium oxide, said catalytic activity being lost owing to the thermal aging process, can be at least partly restored. The two-stage process is based on the fact that strontium and/or barium compounds formed during the thermal aging with the support material, which also comprise platinum, are recycled to the catalytically active forms by controlled treatment with specific gas mixtures.

Abstract: Nitrogen oxide storage catalysts are used to remove the nitrogen oxides present in the lean exhaust gas of lean-burn engines. Storage catalysts are thermally aged by high temperatures. Ageing is due to sintering of the catalytically active noble metal components of the catalyst and to formation of compounds of the storage components with the support materials. According to the invention, the formation of compounds of the storage materials can be largely reversed by treatment of the storage material with a gas mixture containing carbon dioxide, optionally water vapor and optionally nitrogen oxides at temperatures in the range from 200° C. to 950° C., preferably from 300° C. to 700° C. The reactivation can be carried out under emission-neutral conditions directly in the vehicle during driving operation by setting of suitable exhaust gas conditions and regulating the air/fuel ratio.

Abstract: Nitrogen oxide storage catalysts are used for removing the nitrogen oxides present in the lean-burn exhaust gas of lean-burn engines. Here, the purifying action is based on the nitrogen oxides being stored in the form of nitrates by the storage material of the storage catalyst during a lean-burn operating phase of the engine and the previously formed nitrates being decomposed in a subsequent rich-burn operating phase of the engine and the nitrogen oxides which are being liberated again being reacted with the reducing exhaust gas constituents over the storage catalyst to form nitrogen, carbon dioxide and water. Storage catalysts are thermally aged by high temperatures. The aging is due to sintering of the catalytically active noble metal components of the catalyst and to formation of compounds of the storage components with the support materials.

Abstract: Nitrogen oxide storage catalysts are used for removing the nitrogen oxides present in the lean-burn exhaust gas of lean-burn engines. Here, the purifying action is based on the nitrogen oxides being stored in the form of nitrates by the storage material of the storage catalyst during a lean-burn operating phase of the engine and the previously formed nitrates being decomposed in a subsequent rich-burn operating phase of the engine and the nitrogen oxides which are being liberated again being reacted with the reducing exhaust gas constituents over the storage catalyst to form nitrogen, carbon dioxide and water. Storage catalysts are thermally aged by high temperatures. The aging is due to sintering of the catalytically active noble metal components of the catalyst and to formation of compounds of the storage components with the support materials.

Abstract: A nitrogen oxide storage material which is based on storage compounds of elements selected from the group consisting of magnesium, calcium, strontium, barium, the alkali metals, the rare earth metals and mixtures thereof and has a homogeneous magnesium-aluminium mixed oxide doped with cerium oxide as support material for the storage compounds is described. Nitrogen oxide storage catalysts using this storage material display a broad working range, a high storage efficiency and good ageing resistance.