Process and system for purifying exhaust gases of an internal-combustion engine

US6119450A · kind A · utility

Assignee

• Daimlerchrysler AG · US

Inventors

• Walter Boegner · Waiblingen, DE
• Guenter Karl · Eßlingen, DE
• Bernd Krutzsch · Köngen, DE
• Christof Schoen · Winnenden, DE
• Dirk Voigtlaender · Ditzingen, DE
• Guenter Wenninger · Stuttgart, DE

Key dates

• Filing date: Jan 25, 1999
• Grant date: Sep 19, 2000
• Expiry date: Jan 25, 2019

Classification

• Technology area (CPC F): Mechanical Engineering; Lighting; Heating
• CPC primary: F02B1/04
• WIPO field: Environmental technology
• WIPO sector: Chemistry

Abstract

An internal-combustion engine includes an engine control system that permits a change-over between a lean operation and a rich operation of the internal-combustion engine, and an exhaust gas purification system. A .lambda.-probe, an SO.sub.x storage catalyst and an NO.sub.x storage catalyst are successively arranged in an exhaust gas line behind the engine. At the start of desulfurization of the SO.sub.x storage catalyst, a change-over takes place from the lean to the rich operation of the engine. Secondary air is fed into the exhaust gas line; a predetermined .lambda. value of the exhaust gases mixed with secondary air and a temperature in the SO.sub.x storage catalyst are measured. At the end of the desulfurization, a change-over takes place from the rich to a lean operation of the engine.