Method for reducing emission of nitrogen oxide in a motor vehicle having a lean burning internal combustion engine

US8806851B2 · kind B2 · utility

Assignee

• Daimler AG · DE

Inventors

• Cyrill Kammer · Bad Urach, DE
• Berthold Keppeler · Owen, DE
• Jochen Lahr · Stuttgart, DE
• Markus Paule · Bad Marienberg, DE
• Anke Traebert · Stuttgart, DE
• Nicole Werquet · Stuttgart, DE
• Axel Zuschlag · Ditzingen, DE

Key dates

• Filing date: Sep 9, 2008
• Grant date: Aug 19, 2014
• Expiry date: Mar 1, 2030

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y02T10/40
• WIPO field: Environmental technology
• WIPO sector: Chemistry

Abstract

In a method for reducing the emission of nitrogen dioxide in a motor vehicle having an exhaust gas purification system having an SCR catalytic converter with adsorption centers for nitrogen oxides, an exhaust gas enriched with ammonia is supplied to the SCR catalytic converter above an operating temperature. Below the operating temperature, the exhaust gas supplied to the SCR catalytic converter is enriched with a material such that an adsorption of nitrogen oxides is inhibited at corresponding adsorption centers of the SCR catalytic converter. In order to reduce the overall NOx emissions below a first, predeterminable amount, an exhaust gas enriched with ammonia is supplied to the SCR catalytic converter and the NO2 portion of the total NOx emissions is reduced below a second, predeterminable amount in that NO2 is converted with hydrocarbons stored in the SCR catalytic converter.