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

US6766642B2 · kind B2 · utility

Assignee

• Daimlerchrysler AG · US

Inventors

• Klaus Binder · Munich, DE
• Josef Gunther · Marbach am Neckar, DE
• Andreas Hertzberg · Markgröningen, DE
• Brigitte Konrad · Blaustein, DE
• Bernd Krutzsch · Köngen, DE
• Heinz-Jost Ölschlegel · Notzingen, DE
• Stefan Renfftlen · Eislingen/Fils, DE
• Dirk Voigtlander · Ditzingen, DE
• Michel Weibel · Großburgwedel, DE
• Marko Weirich · Mannheim, DE
• Gunter Wenninger · Stuttgart, DE
• Rolf Wunsch · Malsch, DE

Key dates

• Filing date: Jun 26, 2002
• Grant date: Jul 27, 2004
• Expiry date: Jun 26, 2022

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y02T10/12
• WIPO field: Chemical engineering
• WIPO sector: Chemistry

Abstract

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 H2S 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 (H2S); feeding the hydrogen sulphide to an SCR catalytic converter which is arranged downstream of the nitrogen oxide storage catalytic converter in the exhaust-gas aft…