Method and device for reducing the nitrogen oxides in the exhaust gas of a combustion system

US6408619B1 · kind B1 · utility

Assignee

• Siemens Aktiengesellschaft · DE

Inventors

• Gerhard Wissler · Geiselhöring, DE
• Gunther Pajonk · Zapfendorf, DE
• Manfred Weigl · Viehhausen, DE
• Lothar Hofmann · Burgkunstadt, DE

Key dates

• Filing date: Jun 19, 2000
• Grant date: Jun 25, 2002
• Expiry date: Jun 19, 2020

Classification

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

Abstract

When determining the amount of a reducing agent solution to be introduced into the exhaust gas of a combustion system, in particular of a diesel engine, for catalytically reducing the nitrogen oxides by the SCR process, the concentration of the reducing agent in the reducing agent solution as well as the parameters characterizing the operating state of the combustion system, the exhaust gas and/or the catalyst are taken into consideration. As a result, the safety margin with respect to a theoretically optimum amount to be introduced that is required to avoid a leakage of reducing agent can be reduced, whereby the conversion rate of the nitrogen oxides is improved.