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

US6408620B1 · kind B1 · utility

Assignee

• Daimlerchrysler AG · US

Inventors

• Walter Boegner · Waiblingen, DE
• Josef Gunther · Marbach am Neckar, DE
• Hans-Peter Holzt · Eßlingen, DE
• Bernd Krutzsch · Köngen, DE
• Stefan Renfftlen · Eislingen/Fils, DE
• Christof Schon · Winnenden, DE
• Dirk Voightländer · Ditzingen, DE
• Michel Weibel · Großburgwedel, DE
• Gunter Wenninger · Stuttgart, DE

Key dates

• Filing date: Dec 15, 2000
• Grant date: Jun 25, 2002
• Expiry date: Dec 15, 2020

Classification

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

Abstract

A method for operating an exhaust-gas cleaning system having an NOx adsorption accumulator and an SOx trap, includes, in normal operating phases, feeding the exhaust gas to be cleaned first via the SOx trap and then via the NOx adsorption accumulator. The normal operating phases are from time to time interrupted by desulphurization phases for desulphurizing the SOx trap. Means are provided for controlling the direction of flow of the exhaust stream so that it optionally passes firstly via the SOx trap and then via the NOx adsorption accumulator, or firstly via the NOx adsorption accumulator and then via the SOx trap, so that during the desulphurization phases the exhaust gas can be passed firstly via the NOx adsorption accumulator and then via the SOx trap.