Umicore Ag & Co Kg

Degussa Aktiengesellschaft

Umicore Galvanotechnik Gmbh

Jürgen Gieshoff

Thomas Kreuzer

Egbert Lox

Marcus Pfeifer

Martin Votsmeier

Paul Spurk

Yvonne Demel

Nicola Soeger

Ulrich Goebel

Stephan Malmberg

Barry Van Setten

Tobias Kuhl

Harald Klein

Fei Wen

Juliane Kluge

Ulrich Neuhausen

Hartmut Finkbeiner

Juliane Theis

Frank-Walter Schütze

Roger Staab

Frank Schütze

Markus Pfeifer

Martin Votsmeir

Egbert SJ Lox

Harald Krieg

The invention relates to a catalyst comprising a small-pore zeolite that contains iron and copper and has a maximum ring size of eight tetrahedral atoms, characterized in that the channel width of the small-pore zeolite amounts to &#x3e;3.8 &#x212b; (0.38 nm) in at least one dimension.

Active SCR catalyst

When a nitrogen oxide storage catalyst is being regenerated, the regeneration may be terminated for example as a result of a premature load change in the engine, which can lead to incomplete emptying of the storage catalyst. The residual filling level which remains in the catalyst following an incomplete regeneration of this nature is used as the starting value for calculation of the filling level during the next storage phase. After incomplete regeneration, the nitrogen oxide conversion rate is initially greater than would be expected, on account of the residual filling level. By taking this increased conversion rate into account when calculating the filling level during the storage phase, it is possible to further improve the accuracy of the calculation.

Method for determining the instant at which a nitrogen oxide storage catalyst is switched from the storage phase to the regeneration phase and for diagnosing the storage properties of this catalyst

The present invention describes an exhaust-gas purification system for an internal combustion engine made of an oxidation catalyst arranged close to the engine, a subsequent hydrocarbon adsorber and a particulate filter arranged downstream thereof and provided with another oxidation catalyst. The oxidation catalyst ensures that emission limits with respect to carbon monoxide and hydrocarbons are satisfied in normal driving mode. During operating states with exhaust-gas temperatures below about 200&#xb0; C., the oxidation catalyst can no longer oxidize carbon monoxide and hydrocarbons. Instead, the hydrocarbons are adsorbed by the hydrocarbon adsorber during these operating phases. In order to initiate the periodical regeneration of the particulate filter, the exhaustgas temperature of the internal combustion engine is raised by engine modifications. The increased exhaust-gas temperature leads to desorption of the previously stored hydrocarbons, which are then burned at the oxidation catalyst of the particulate filter, thereby supporting the regeneration of the particulate filter.

Exhaust-gas purification system with particulate filter and method of operation thereof with improved regeneration of the particulate filter

The invention relates to a catalyst arrangement for purifying the exhaust gases of internal combustion engines operated under lean conditions. It is proposed that a thinwalled, porous carrier be coated on one side with a nitrogen oxide storage catalyst and on the other side with an SCR catalyst. When the exhaust gas is passed through the catalytic coatings and the support material, a significant improvement in the nitrogen oxide conversion is achieved compared to a series arrangement of the catalysts on separate carriers. Wall flow filters have been found to be useful as thin-walled carriers.

Catalyst arrangement and method of purifying the exhaust gas of internal combustion engines operated under lean conditions

This invention relates to a method of operating a catalyst for treating the exhaust gas of an internal combustion engine, the catalyst comprising, in addition to catalytically active noble metals, also storage components for storing hydrocarbons. During engine operating phases at low exhaust-gas temperatures, such a catalyst stores the hydrocarbons contained in the exhaust gas without burning them. When the exhaust-gas temperature rises, these hydrocarbons are desorbed again and then oxidized at the catalytically active noble metals. This process can lead to uncontrolled, vigorous combustion of the hydrocarbons stored on the catalyst and, therefore, damage to the catalyst. According to the invention, this damage is avoided by continuously calculating the respective loading of the storage components with hydrocarbons and repeatedly regenerating the storage components depending on the loading by temporarily raising the exhaust-gas temperature before damage to the catalyst can occur.

Method of operating a catalyst which includes components for storing hydrocarbons

The present invention relates to the catalytic conversion of hydrocarbons for generating a gas that is rich in hydrogen, to the use of said apparatus and to a process for generating hydrogen. The apparatus comprises a reforming catalyst (), as well as a means () for supplying hydrocarbons to the catalyst. The reforming catalyst is arranged in an exhaust pipe () through which the exhaust gases of combustion processes are passed.

Process and apparatus for catalytic conversion of hydrocarbons for generating a gas rich in hydrogen

The present invention relates to a catalyst for the purification of exhaust gases from an internal combustion engine, which comprises a catalytically active coating on an inert ceramic or metal honeycomb body, said coating comprising at least one platinum group metal selected from the group consisting of platinum, palladium, rhodium and iridium on a fine, oxidic support material. As an oxidic support material, the catalyst comprises a low-porosity material on the basis of silicon dioxide that comprises aggregates of essentially spherical primary particles having an average particle diameter of between 7 and 60 nm.

Catalyst featuring silicone dioxide based support material for the purification of exhaust gases

An exhaust gas treatment unit for the selective catalytic reduction of nitrogen oxides under lean exhaust gas conditions which contains at least one catalyst with catalytically active components for selective catalytic reduction (SCR components). The exhaust gas treatment unit is characterised in that the catalyst also contains, in addition to SCR components, at least one storage component for nitrogen oxides (NOx components).

Exhaust gas treatment unit for the selective catalytic reduction of nitrogen oxides under lean exhaust gas conditions and a process for the treatment of exhaust gases

The present invention relates to a method of removing nitrogen oxides from the exhaust gas of a lean-burn internal combustion engine by selective catalytic reduction (SCR) using ammonia. The exhaust gas is routed first over a platinum-containing pre-catalyst and then over an SCR catalyst. The ammonia needed for the selective catalytic reduction is added to the exhaust gas upstream of the pre-catalyst at an exhaust-gas temperature below 250&#xb0; C., while it is supplied to the exhaust gas between the pre-catalyst and the SCR catalyst at an exhaust gas temperature above 150&#xb0; C. By adopting this procedure, a very large temperature range for the selective catalytic reduction with high nitrogen conversion rates is obtained.

Method of removing nitrogen oxides from the exhaust gas of a lean-burn internal combustion engine and exhaust-gas purification system therefor

The invention relates to a method and an apparatus of operating a drive system comprising an engine and an exhaust gas purification unit containing a catalyst, where the engine emits an exhaust gas having an exhaust gas temperature and the catalyst has a catalytic activity for the purification of the exhaust gas. In the method, an aging-induced decrease in the catalytic activity of the catalyst is compensated at least part of the time by increasing the exhaust gas temperature of the engine.

Method of operating a system comprising a diesel engine and catalyst for exhaust gas purification

The present invention provides an exhaust gas treatment unit for an internal combustion engine. A first catalyst unit produces ammonia from corresponding constituents in a rich exhaust gas composition. A second catalyst unit that is located downstream of the first catalyst unit temporarily stores the ammonia produced by the first catalyst unit in the presence of a rich exhaust gas composition. In the presence of a lean exhaust gas composition, the nitrogen oxides present in the exhaust gas are subjected to a reduction reaction using the temporarily stored ammonia as reducing agent. The exhaust gas treatment unit also contains a third catalyst unit that is located between the other two catalyst units, and oxidizes the nitrogen oxides present in the exhaust gas at lean exhaust gas conditions to a such an extent that 25 to 75 vol. % of the nitrogen oxides entering the second catalyst unit consist of nitrogen dioxide.

Exhaust gas treatment units for internal combustion engines and processes for operating them

An auxiliary heating system for a motor vehicle with an internal combustion engine. The auxiliary heating includes an emission control catalyst and a heat exchanger, integrated in the converter housing in front of and/or behind the catalyst, which provides the reaction heat released by the catalyst and the remaining heat of the exhaust gas to the heating of the passenger compartment. The heat generation may be increased by the injection of a fuel/air mixture before the catalyst and by using the catalyst as a catalytic burner and can be adapted to the heat requirements. The auxiliary heating of the invention prevents possible thermal damage of the catalyst during operation as a catalytic burner without many regulating elements by cooling the catalyst radiation. For this purpose, the heat exchanger is provided with an exchange surface which can freely exchange radiation with the radiant surface of the catalytic element.

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Biebergemünd, Germany

Jürgen Gieshoff