Method for metering ammonia into the exhaust-gas region of an internal combustion engine and device for implementing the method

US7373775B2 · kind B2 · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

• Norbert Breuer · Ditzingen, DE
• Katharina Körting · Schorndorf, DE

Key dates

• Filing date: Dec 21, 2004
• Grant date: May 20, 2008
• Expiry date: Dec 21, 2024

Classification

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

Abstract

A method for metering ammonia into the exhaust-gas region of an internal combustion engine and a device for implementing the method. The ammonia storage capacity of an SCR catalytic converter situated in the exhaust-gas region of the internal combustion engine is utilized. After the internal combustion engine has been switched off, ammonia is introduced into the exhaust-gas region in front of the SCR catalytic converter. Thus, following a renewed start-up of the internal combustion engine, the ammonia required in the SCR catalytic converter for reducing the nitrogen oxides contained in the exhaust gas of the internal combustion engine are already available before an ammonia source is ready for operation. The procedure eliminates the need for a pressure storage of ammonia in the switched-off state of the internal combustion engine.