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

US6872365B1 · kind B1 · utility

Assignee

• Daimlerchrysler AG · US

Inventors

• Walter Boegner · Waiblingen, DE
• Martin Hartweg · Erbach, DE
• Brigitte Konrad · Blaustein, DE
• Bernd Krutzsch · Köngen, DE
• Michel Weibel · Großburgwedel, DE
• Guenter Wenninger · Stuttgart, DE

Key dates

• Filing date: Mar 24, 2000
• Grant date: Mar 29, 2005
• Expiry date: Mar 24, 2020

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y02A50/20
• WIPO field: Chemical engineering
• WIPO sector: Chemistry

Abstract

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.