Daimler Chrysler Ag

Daimler-benz Ag

Daimler Ag

Mercedes-benz Aktiengesellschaft

Daimlerchrylser Ag

Purem Abgassysteme Gmbh & Co. Kg

Bernd Krutzsch

Guenter Wenninger

Walter Boegner

Michel Weibel

Dirk Voigtlaender

Stefan Renfftlen

Friedrich Wirbeleit

Andreas Hertzberg

Christof Schoen

Rolf Wunsch

Markus Paule

Arno Nolte

Brigitte Konrad

Frank Duvinage

Stefan Pischinger

Guenter Karl

Norbert Waldbuesser

Marko Weirich

Brigitte Bandl-Konrad

Walter Friess

Karl-Ernst Haak

G&uuml;nter Wenninger

Martin Hartweg

Klaus Binder

Michael Kraemer

Josef G&uuml;nther

Dirk Voigtl&auml;nder

Günter Wenninger

Anton Kerckhoff

Christof Sch&ouml;n

Juergen Steinwandel

Berthold Keppeler

Andreas Kaupert

Frank Thoma

Arnold Lamm

Gernot Hertweck

Steffen Oliver Wieland

Leonhard Walz

Andrea Seibold

Rainer Schmidberger

Christian Enderle

Klaus Wunderlich

Viktor Pfeffer

Gregor Renner

Andreas Docter

Christian Goerigk

Georg Huthwohl

Bernd Maurer

Thomas Liebscher

Rudolf Maly

Tillmann Braun

Theodor Staneff

Bernhard Vogel

Nicholas Fekete

Hans Fausten

Rainer Willneff

Norbert Ruzicka

Martin Stroeer

Werner Weisweiler

Wim Verrelst

Martina Heinau

Leopold Mikulic

Alexander Funk

Rudiger Pfaff

Stefan Kurze

Dirk Voigtländer

Steffen Digeser

Martin Bechtold

Klaus-Juergen Marquardt

Oliver Ebelsheiser

Hans-Peter Holzt

Detlef Scharr

Josef Gunther

Gert Withalm

Hans G Mueller

Gunter Wonninger

Michael Pabel

Christof Schon

Josef Günther

Karl-Ernest Haak

Heinz-Jost Ölschlegel

Michel Weibl

G&uuml;nter Karl

Brititte Konrad

Josef Guenther

Dirk Voightl&auml;nder

Heinz-Jost &Ouml;lschlegel

Miechel Weibel

Kirsten Hardenberg

Doris Schr&ouml;der

Renate Marx

An exhaust gas aftertreatment installment and associated exhaust gas aftertreatment method utilizes a nitrogen oxide storage catalytic converter and an SCR catalytic converter. A particulate filter is provided upstream of the nitrogen oxide storage catalytic converter or between the latter and the SCR catalytic converter or downstream of the SCR catalytic converter. The time of regeneration operating phases of the nitrogen oxide storage catalytic converter can be determined as a function of the nitrogen oxide content of the exhaust gas downstream of the nitrogen oxide storage catalytic converter or of the SCR catalytic converter and/or as a function of the ammonia loading of the latter. Moreover, a desired ammonia generation quantity can be determined for a respective regeneration operating phase. The installation and method are adopted for use for motor vehicle internal combustion engines and other engines which are operated predominantly in lean-burn mode.

Exhaust gas aftertreatment installation and method

The exhaust gas aftertreatment device according to the invention having a reforming unit for generating hydrogen by steam reforming, partial oxidation of hydrocarbons and/or mixed forms thereof is distinguished by the fact that the reforming unit is arranged directly in the main exhaust gas stream from an internal combustion engine. The steam and residual oxygen which are required for the reforming preferably originate from the exhaust gas. The step of providing the required reducing agents consists in briefly switching the internal combustion engine, which is predominantly operated in lean-burn mode and the exhaust gas from which is undergoing the aftertreatment, to rich-burn mode, allowing reforming by means of the reforming reactor according to the invention using the hydrocarbons that are present in the exhaust gas.

Device and method for exhaust gas aftertreatment

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

A filter assembly for an exhaust gas purification system of an internal combustion engine. The filter assembly, has porous filter plate elements, connected with each other on their outer as well as on their inner peripheries, forming in pairs as filter pockets. Catalytic agents such as ammonia are applied to the filter pockets on the outer and/or inner sides to oxidize carbon black contained in the combustion gas. In particular, this filter assembly is compact and can be used for diesel engines of motor vehicles.

Filter assembly for an exhaust gas purification system

An exhaust-gas cleaning system for cleaning exhaust gas from a combustion source so as to remove at least nitrogen oxides contained therein is provided. An ammonia-generation catalytic converter for generating ammonia uses constituents of at least some of the exhaust gas emitted from the combustion source during ammonia-generation operating phases. A downstream nitrogen oxide reduction catalytic converter is provided for reducing nitrogen oxides which are contained in the exhaust gas emitted from the combustion source using the ammonia generated as the reducing agent. According to the invention, a plasma generator for using plasma technology to generate reactive particles, which promote the ammonia-generation reaction, from constituents of the exhaust gas fed to the ammonia-generation catalytic converter during the ammonia-generation operating phases is connected upstream of the ammonia-generation catalytic converter. This ensures that sufficient ammonia is generated even at relatively low exhaust-gas temperatures.

Exhaust gas cleaning system having internal ammonia production for reducing nitrogen oxides

In a method for burning deposited soot particles in a particle filter on an exhaust device of a diesel engine, first of all, in a known way, a catalytic converter produces NO from exhaust gas. This NO reduces the ignition temperature of soot to such an extent that it burns at normal exhaust-gas temperature. Furthermore, there is provision to add fuel additive, which likewise allows the ignition temperature of the soot to be reduced. The sulphur content in the fuel is determined, and either generation of NO or the addition of additive is used as a function of this measurement. This preferably takes place automatically. To determine the sulphur content, it is possible, for example, to use a sulphur sensor in the tank.

Method and device for treating diesel exhaust gas

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 purification device in a vehicle, wherein a reforming reactor is provided for extraction of hydrogen from fuel and the hydrogen is supplied to an exhaust gas stream of an internal combustion engine upstream of the exhaust gas catalytic converter, wherein the reforming reactor includes a supply device for oxygen and/or water, wherein the reforming reactor is connected with a side branch of the exhaust gas conduit and wherein oxygen and water for reforming are supplied in the form of an exhaust gas partial stream via the side branch.

Device and method for cleansing exhaust gas

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

In a method for the periodic desulphurization of a nitrogen-oxide or sulphur-oxide accumulator of an exhaust-gas cleaning system of an internal-combustion engine, during respective desulphurization periods, the accumulator is fed secondary air by secondary-air supply means, and is fed an engine exhaust gas which contains a reducing agent by setting a rich engine air ratio. At least during part of the desulphurization period, after a predeterminable desulphurization temperature has been reached, the accumulator air ratio is set, by suitably alternating the secondary air quantity supplied and/or the engine air ratio, between an oxidizing or stoichiometric atmosphere, and a reducing atmosphere.

Method for the periodically desulfating a nitrogen oxide or sulfur oxide accumulator of an exhaust gas cleaning system

A method for the desulfurization of a nitrogen oxide adsorber of an exhaust gas purification device for a combustion system employs desulfurization phases that are intermittently implemented by a desulfurization control unit. During each desulfurization phase, the carbon monoxide concentration and/or the lambda value of the exhaust gas stream exiting the nitrogen oxide adsorber is recorded. A localized maximum that appears in the recorded course of the carbon monoxide concentration over time, or a downward slope that appears in the established course of the lambda value over time, falling from a temporary plateau value, is employed as criterion for terminating the desulfurization phase. The method may be used, for example, in exhaust gas purification devices in primarily lean-burning vehicle combustion engines.

Method and apparatus for desulfurizing a nitrogen oxide adsorber

A method for operating an exhaust-gas cleaning system having an NO adsorption accumulator and an SO trap, includes, in normal operating phases, feeding the exhaust gas to be cleaned first via the SO trap and then via the NO adsorption accumulator. The normal operating phases are from time to time interrupted by desulphurization phases for desulphurizing the SO trap. Means are provided for controlling the direction of flow of the exhaust stream so that it optionally passes firstly via the SO trap and then via the NO adsorption accumulator, or firstly via the NO adsorption accumulator and then via the SO trap, so that during the desulphurization phases the exhaust gas can be passed firstly via the NO adsorption accumulator and then via the SO trap.

Exhaust-gas cleaning system with nitrogen oxide accumulator catalyst and sulphur oxide trap and operating method therefor

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Denkendorf, Germany

Bernd Krutzsch