Process for lowering nitrogen oxide levels in combustion engine exhaust gas

US6001318A · kind A · utility

Assignee

• Degussa-Huels AG · DE

Inventors

• Hans Tillaart · Alzenau, DE
• Jurgen Leyrer · Rheinfelden (Baden), DE
• Egbert Lox · Hanau, DE
• Thomas Kreuzer · Karben, DE
• Stephan Eckhoff · Alzenau, DE

Key dates

• Filing date: Dec 22, 1997
• Grant date: Dec 14, 1999
• Expiry date: Dec 22, 2017

Classification

• Technology area (CPC F): Mechanical Engineering; Lighting; Heating
• CPC primary: F01N2610/03
• WIPO field: Chemical engineering
• WIPO sector: Chemistry

Abstract

A process is disclosed for lowering nitrogen oxide levels in combustion engine exhaust gas by a reduction catalyst and by controlling the exhaust gas temperature upstream from the catalyst to a constant value, at which the catalyst exhibits maximum conversion for nitrogen oxides. It is possible to maintain maximum conversion over a wide range of engine outlet temperatures of the exhaust gas.