High-efficiency SCR catalytic converter

US8484954B2 · kind B2 · utility

Assignee

• DEUTZ AKTIENGESELLSCHAFT · DE

Inventor

• Hans Walter Knuth · Cologne, DE

Key dates

• Filing date: May 16, 2009
• Grant date: Jul 16, 2013
• Expiry date: Jul 11, 2029

Classification

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

Abstract

A method and a device for selectively purifying the exhaust gas of an internal combustion engine using a selective catalytic reduction (SCR) catalytic converter (2), wherein a reducing agent is metered to the exhaust gas prior to entry into the SCR catalytic converter (2). An overdose of the reducing agent is added to the exhaust gas, and the exhaust gas, after exiting the SCR catalytic converter, is fed in part through an oxidation catalytic converter (5) and in part to a second SCR catalytic converter (8) via a bypass (6) circumventing the oxidation catalytic converter. In the oxidation catalytic converter (5), one half of the excess NH3 flowing out of the first SCR catalytic converter (2) is converted to NOx and reacts to form non-hazardous nitrogen after mixing with the other half of the excess NH3 flowing unchanged through a bypass.