Methods of controlling reductant addition

US7861516B2 · kind B2 · utility

Assignee

• Johnson Matthey Public Limited Company · GB

Inventors

• Eive Tord Ronny Allansson · Kungsbacka, SE
• Anders Andreasson · Kungsängen, SE
• Claus Friedrich Goersmann · Maidstone, GB
• Mats Lavenius · Göteborg, SE
• Martyn Vincent Twigg · Cambridge, GB
• Andrew Peter Walker · Royston, GB

Key dates

• Filing date: Jun 18, 2004
• Grant date: Jan 4, 2011
• Expiry date: Mar 17, 2027

Classification

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

Abstract

An exhaust system for a vehicular lean-burn internal combustion engine includes a NOx reduction catalyst, a source reductant, means (20) for contacting the catalyst with the reductant, means for sensing the temperature of the exhaust gas and/or the catalyst bed and means, when in use, for controlling reductant addition. The reductant addition control means supplies an amount of reductant to the catalyst at a rate corresponding to a measured temperature value of the exhaust gas and/or catalyst bed, which temperature value has been pre-determined to correlate, in use, with an amount of NOx in the exhaust gas.