Daimler Chrysler Ag

Marko Weirich

Bernd Krutzsch

Michel Weibel

Andreas Hertzberg

Klaus Binder

Dirk Voigtlaender

Brigitte Konrad

Stefan Renfftlen

Rolf Wunsch

Guenter Wenninger

Arno Nolte

Christof Schoen

Dirk Voigtl&auml;nder

Josef G&uuml;nther

Günter Wenninger

G&uuml;nter Wenninger

Josef Gunther

Dirk Voigtländer

Heinz-Jost &Ouml;lschlegel

Josef Günther

Miechel Weibel

Josef Guenther

Brititte Konrad

Heinz-Jost Ölschlegel

An internal combustion engine includes an exhaust-gas aftertreatment device, and an operating method is for operating the internal combustion engine. The internal combustion engine is operable with a lean mixture and a rich mixture, the internal combustion engine having an exhaust-gas aftertreatment device, which includes a nitrogen oxide storage catalytic converter and a particle filter. When lean exhaust gas flows through the nitrogen oxide storage catalytic converter, it removes nitrogen oxides from the exhaust gas by storing them, and, when reducing exhaust gas flows through the nitrogen oxide storage catalytic converter, it produces ammonia through reduction of stored and/or supplied nitrogen oxides and releases it to the exhaust gas. Downstream from the nitrogen oxide storage catalytic converter, the exhaust-gas aftertreatment device includes a SCR catalytic converter, which reduces nitrogen oxides contained in the exhaust gas, using ammonia produced by the nitrogen oxide storage catalytic converter.

Exhaust-gas aftertreatment device with nitrogen oxide storage catalytic converter, and operating method therefor

1. Motor vehicle having an activated carbon filter and method for regenerating an activated carbon filter. 2. A motor vehicle () is proposed, comprising an, in particular, direct-injection internal combustion engine (), a fuel tank () and an aeration device () for the fuel tank that comprises an activated carbon filter () and a regeneration device () for regenerating the activated carbon filter, and a method for regenerating an activated carbon filter in a motor vehicle comprising an, in particular, direct-injection internal combustion engine. 2.2. According to the invention, a regeneration device () is provided in the motor vehicle and is assigned a control device () which undertakes an activation of the regeneration device () in the overrun mode of the internal combustion engine (); for the method, provision is made for an overrun mode of the internal combustion engine to be detected in one method step and for a regeneration device which is assigned to the activated carbon filter and is intended for purging the activated carbon filter with fresh air to be activated in a subsequent method step. 2.3. To be used in motor vehicles, in particular passenger vehicles.

Motor vehicle comprising an activated carbon filter and method for regenerating an activated carbon filter

An exhaust-gas aftertreatment device with a nitrogen oxide storage catalytic converter for an internal combustion engine, and a method for operating an exhaust-gas aftertreatment device which is assigned to an internal combustion engine and has a nitrogen oxide storage catalytic converter. An SCR catalytic converter is arranged in the exhaust-gas aftertreatment device, it being possible for the exhaust gas which emerges from the nitrogen oxide storage catalytic converter to be fed to the SCR catalytic converter when the internal combustion engine is in a desulphating operating mode with a reducing exhaust-gas composition, in order for H S which is formed during the desulphating to be removed. When the internal combustion engine is in a desulphating operating mode, the following steps are performed: establishing a reducing exhaust gas composition upstream of the nitrogen oxide storage catalytic converter; releasing the sulphur which is bound in the nitrogen oxide storage catalytic converter, to form hydrogen sulphide (H S); feeding the hydrogen sulphide to an SCR catalytic converter which is arranged downstream of the nitrogen oxide storage catalytic converter in the exhaust-gas aftertreatment device; and reacting the hydrogen sulphide in the SCR catalytic converter to form sulphur dioxide under reducing exhaust-gas conditions. The method may be used in motor vehicles, e.g., passenger cars, with lean-burn internal combustion engines.

An exhaust-gas cleaning system removes at least nitrogen oxides contained in exhaust-gas from a combustion source. An ammonia-generation catalytic converter generates ammonia using constituents of at least some of the exhaust gas emitted from the combustion source during ammonia-generation operating phases. Downstream a nitrogen oxide reduction catalytic converter reduces nitrogen oxides which are contained in the exhaust gas emitted from the combustion source using the ammonia generated as reducing agent. A nitrogen monoxide generation unit is situated outside the combustion source, for enriching the exhaust gas which is fed to the ammonia-generation catalytic converter with generated nitrogen monoxide during the ammonia-generation operating phases. The system is used for cleaning exhaust gases of motor vehicle internal-combustion engines which are operated predominantly in lean-burn mode, removing nitrogen oxides which are contained therein.

Exhaust-gas cleaning system and method with internal ammonia generation, for the reduction of nitrogen oxides

A method and apparatus for purifying an exhaust gas of an internal combustion engine includes an ammonia generating catalyst for generating ammonia from nitrogen oxides contained in the exhaust gas to be purified, and a nitrogen oxide reducing catalyst downstream of the ammonia generating catalyst, for reduction of nitrogen oxides contained in the exhaust gas to be purified. Generated ammonia is used as the reducing agent. A nitrogen oxide adsorption catalyst is arranged upstream of the ammonia generating catalyst, or the ammonia generating catalyst is arranged in an exhaust pipe branch which pertains to only a part of several separately controllable internal-combustion sources. One or more additional exhaust pipe branches assigned to the other internal-combustion sources and lead to the nitrogen oxide reducing catalyst, while bypassing the ammonia generating catalyst. The part of the internal-combustion sources pertaining to the exhaust pipe branch of which contains the ammonia generating catalyst is operated either continuously or intermittently in a rich mode. Also, one or more combustion sources which feed their exhaust gas to the nitrogen oxide adsorption catalyst may be operated alternately in a lean and rich mode.

Exhaust gas purification process and apparatus with internal generation of ammonia for reducing nitrogen oxide

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Mannheim, Germany

Marko Weirich