Method for determining the instant at which a nitrogen oxide storage catalyst is switched from the storage phase to the regeneration phase and for diagnosing the storage properties of this catalyst

US7735312B2 · kind B2 · utility

Assignee

• UMICORE AG & CO. KG · DE

Inventors

• Martin Votsmeier · Bruchköbel, DE
• Juliane Kluge · Munich, DE
• Ulrich Goebel · Hattersheim, DE
• Jurgen Gieshoff · Bad Orb, DE
• Thomas Kreuzer · Karben, DE

Key dates

• Filing date: Feb 4, 2005
• Grant date: Jun 15, 2010
• Expiry date: Jan 13, 2027

Classification

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

Abstract

When a nitrogen oxide storage catalyst is being regenerated, the regeneration may be terminated for example as a result of a premature load change in the engine, which can lead to incomplete emptying of the storage catalyst. The residual filling level which remains in the catalyst following an incomplete regeneration of this nature is used as the starting value for calculation of the filling level during the next storage phase. After incomplete regeneration, the nitrogen oxide conversion rate is initially greater than would be expected, on account of the residual filling level. By taking this increased conversion rate into account when calculating the filling level during the storage phase, it is possible to further improve the accuracy of the calculation.