Exhaust gas post treatment system

US7984609B2 · kind B2 · utility

Assignee

• MAN Truck &Bus AG · DE

Inventors

• Andreas Döring · Unterhaching, DE
• Klaus Richter · Nauheim, DE

Key dates

• Filing date: Aug 16, 2007
• Grant date: Jul 26, 2011
• Expiry date: May 25, 2030

Classification

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

Abstract

An exhaust gas post treatment system for nitrogen oxide and particle reduction of internal combustion engines operated with excess air. An oxidation catalytic converter is disposed in the exhaust gas stream of the engine for converting at least a portion of the nitric oxide in the exhaust gas into nitrogen dioxide. The first particle separator or filter is disposed in the exhaust gas stream downstream of the oxidation catalytic converter for converting carbon particles accumulated in the separator or filter into carbon monoxide, carbon dioxide, nitrogen and nitric oxide with the aid of nitrogen dioxide contained in the exhaust gas. A partial exhaust gas stream is branched off from the exhaust gas stream upstream of the first separator or filter. A metering device adds reduction agent to the partial exhaust gas stream in the form of ammonia or a material that releases ammonia downstream of the supply location due to hot exhaust gas. A second particle separator or filter is disposed in the partial exhaust gas stream downstream of the supply location. The partial exhaust gas stream returns to the exhaust gas stream downstream of both particle separators or filters. An SCR catalytic co…