Process and apparatus for reducing nitrogen-oxide emissions in exhaust gas

US6176079A · kind A · utility

Assignee

• Daimlerchrysler AG · US

Inventors

• Brigitte Konrad · Blaustein, DE
• Bernd Krutzsch · Köngen, DE
• Dirk Voigtlaender · Ditzingen, DE

Key dates

• Filing date: May 10, 1999
• Grant date: Jan 23, 2001
• Expiry date: May 10, 2019

Classification

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

Abstract

A method of cleaning an exhaust gas from a combustion system that is operated alternately in lean and rich conditions includes intermediately storing nitrogen oxides during lean operation; releasing the stored nitrogen oxides, thereby producing ammonia and storing the ammonia during rich operation; releasing the ammonia, thereby reducing nitrogen oxides in a subsequent lean condition.