Daimler Chrysler Ag

Daimler-benz Ag

Daimler Ag

Mercedes-benz Aktiengesellschaft

Daimlerchrylser Ag

Walter Boegner

Bernd Krutzsch

Guenter Wenninger

Dirk Voigtlaender

Friedrich Wirbeleit

Michel Weibel

Martin Hartweg

Guenter Karl

Christof Schoen

Andrea Seibold

Karl-Ernst Haak

Thomas Fetzer

Bernd Morsbach

Andreas Hertzberg

Stefan Pischinger

Rolf-Dirc Roitzheim

Stefan Renfftlen

Brigitte Konrad

G&uuml;nter Wenninger

Christof Sch&ouml;n

Frank Duvinage

Leonhard Walz

Viktor Pfeffer

Gregor Renner

Christian Goerigk

Rudolf Maly

Michael Kraemer

Walter Friess

Dirk Voigtl&auml;nder

Martina Heinau

Werner Weisweiler

Josef G&uuml;nther

Norbert Ruzicka

Wim Verrelst

Stefan Kurze

Rudiger Pfaff

Hans-Peter Holzt

Christof Schon

Doris Schr&ouml;der

Gunter Wonninger

Christine De Saint-Aubin

Karl-Ernest Haak

Dirk Voightl&auml;nder

Kirsten Hardenberg

Renate Marx

G&uuml;nter Karl

In a method of operating a particle filter in an exhaust system of a motor vehicle internal combustion engine, wherein the particle filter is reconditioned, in intervals, by a soot-burn-off procedure, the amount of noncombustible ashes also collected in the particle filter is reduced by heating the particle filter and supplying to the particle filter, together with the exhaust gas of the internal combustion engine, a reducing agent which reacts with the ash deposits so as to chemically convert the ash deposits such that at least non-metallic ash components are decomposed and carried out of the particle filter by the exhaust gas.

Method of operating a particle filter in the exhaust system of a motor vehicle's internal combustion engine

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

The invention relates to a method and a device for cleaning flowing gases. To reduce the total emissions, nitrogen oxides, especially NO and NOx, are extracted at least partially from the gas to be scrubbed, in the temperature range from 50 and 300&deg; C., preferably between 50 and 150&deg; C. To extract the nitrogen oxides, an intermediate storage medium is used that is composed of a storage material and a supporting material for the storage material. The intermediate storage medium having in particular a composition of the formal chemical formula Ag.CuAl O in an Al O matrix, with the composition being a spinel or being of the spinel type, and with the composition having characteristic spinel lines in the x-ray spectrum, where 0&lE;x<1.

Process and apparatus for cleaning a gas flow

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

An internal-combustion engine includes an engine control system that permits a change-over between a lean operation and a rich operation of the internal-combustion engine, and an exhaust gas purification system. A &lgr;-probe, an SO,storage catalyst and an NO,storage catalyst are successively arranged in an exhaust gas line behind the engine. At the start of desulfurization of the SO,storage catalyst, a change-over takes place from the lean to the rich operation of the engine. Secondary air is fed into the exhaust gas line; a predetermined &lgr; value of the exhaust gases mixed with secondary air and a temperature in the SO,storage catalyst are measured. At the end of the desulfurization, a change-over takes place from the rich to a lean operation of the engine.

Process and system for purifying exhaust gases of an internal-combustion engine

An emission control system for an internal-combustion engine has at least one nitrogen oxide adsorber for the periodic adsorption and desorption of nitrogen oxides contained in the exhaust gas of the internal-combustion engine. A desorption gas pipe has an externally heatable catalyst arranged therein to which a mixture of air and/or exhaust gas can be fed as well as fuel at an at least stoichiometric proportion. This mixture is burned to form a desorbing gas flow which is fed to the respective nitrogen oxide adsorber for the nitrogen oxide desorption.

Emission control system for an internal-combustion engine

A catalyst and method is provided for reducing pollutants in gases. The catalyst is composed of two substances. A first material which is an adsorption material has an adsorbent effect on an additional substance, the additional substance often being a hydrocarbon, such as propene. A second material is an oxidation material. The oxidation material has an oxidizing effect on the pollutant. The adsorption material and the oxidation material are on the same catalyst.

Method and catalyst for reducing pollutants in gases

An internal-combustion engine system includes an internal-combustion engine with a pertaining engine exhaust gas system, an emissions control device having an NO.sub.x storage catalyst arranged in the exhaust gas system, a lambda probe for detecting the engine air ratio and devices for the periodic desulfurization of the catalyst at a raised temperature and a rich air ratio of the latter, as well as to an operating process suitable for this system. The desulfurization devices comprise secondary air feeding devices for feeding secondary air into the NO.sub.x storage catalyst. During the desulfurization phases, the engine is operated at a rich air ratio and secondary air is metered into the catalyst.

Internal-combustion engine system having a nitrogen oxide storage

An internal-combustion engine includes an engine control system that permits a change-over between a lean operation and a rich operation of the internal-combustion engine, and an exhaust gas purification system. A .lambda.-probe, an SO.sub.x storage catalyst and an NO.sub.x storage catalyst are successively arranged in an exhaust gas line behind the engine. At the start of desulfurization of the SO.sub.x storage catalyst, a change-over takes place from the lean to the rich operation of the engine. Secondary air is fed into the exhaust gas line; a predetermined .lambda. value of the exhaust gases mixed with secondary air and a temperature in the SO.sub.x storage catalyst are measured. At the end of the desulfurization, a change-over takes place from the rich to a lean operation of the engine.

Process and system for purifying exhaust gases of an internal-combustion

A method for operating a multicylinder internal combustion engine with at least one adsorber catalytic converter in the exhaust line of the internal combustion engine includes operating the adsorber catalytic converter with periodically alternating adsorption and desorption operation. The exhaust leaving the adsorber catalytic converter in desorption operation is recycled and/or an oxidation catalytic converter is provided upstream of the adsorber catalytic converter. Exhaust recycling takes place occurs selectively in only one set of the cylinders of the internal combustion engine and this set of cylinders is operated in a state of incomplete combustion during desorption operation. Rich afterburning may be performed during desorption operation of the adsorber catalytic converter in the oxidation catalytic converter connected upstream and the oxidation catalytic converter is operated at an increased temperature during short regeneration phases to remove soot.

Method for operating a multicylinder internal combustion engine

The invention relates to a method and a device for cleaning flowing gases. To reduce the total emissions, nitrogen oxides, especially NO and NOx, are extracted at least partially from the gas to be scrubbed, in the temperature range from 50 and 300.degree. C., preferably between 50 and 150.degree. C. To extract the nitrogen oxides, an intermediate storage medium is used that is composed of a storage material and a supporting material for the storage material. The intermediate storage medium having in particular a composition of the formal chemical formula Ag.CuAl.sub.2 O.sub.4 in an Al.sub.2 O.sub.3 matrix, with the composition being a spinel or being of the spinel type, and with the composition having characteristic spinel lines in the x-ray spectrum, where 0.ltoreq.x&lt;1.

Methods and devices for scrubbing gases

A process and apparatus for reducing the nitrogen oxide content in oxygen-containing emissions is provided, particularly for internal-combustion engines, particularly of diesel engines and directly injecting Otto engines for motor vehicles. The nitrogen oxides contained in the exhaust gas are reduced by a suitable reducing agent, such as hydrogen or hydrocarbons, on a DENOX catalyst. For achieving an improved conversion rate for the nitrogen oxides, a combination of hydrogen and hydrocarbons are used as reducing agents. In different operating ranges of the internal-combustion engine only hydrogen, only hydrocarbons, or hydrogen and hydrocarbons are added. Preferably, for this purpose, the quantity of supplied hydrogen or hydrocarbons is reduced or increased with an increasing engine load and/or catalyst temperature and/or rotational engine speed.

Process and apparatus for reducing nitrogen oxides in engine emissions

A motor vehicle exhaust emission control system has two adsorber parts connected in parallel for alternate adsorption and desorption of nitrogen oxides contained in the exhaust from an internal combustion engine and components for conducting further downstream the exhaust that emerges in the adsorber part that is operating at any given time in the adsorption mode and for returning the exhaust that emerges from the other adsorber part that is then operating in the desorption mode, to an intake line of the engine. An oxidizing converter is located upstream of the adsorber part and near the engine for oxidation of the NO contained in the exhaust to form NO.sub.2, so as to permit an increase in the NO.sub.X adsorption rate for the nitrogen adsorber parts.

Internal combustion engine exhaust emission control system with

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Remseck, Germany

Walter Boegner