The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 01, 2008
Filed:
Feb. 26, 2004
Markus Pfeifer, Solingen, DE;
Barry Van Setten, Rodenbach, DE;
Paul Spurk, Weiterstadt, DE;
Yvonne Demel, Frankfurt, DE;
Tobias Kuhl, Hanau, DE;
Jürgen Gieshoff, Biebergemünd, DE;
Egbert Lox, Hochwaldhausen, DE;
Thomas Kreuzer, Karben, DE;
Markus Pfeifer, Solingen, DE;
Barry Van Setten, Rodenbach, DE;
Paul Spurk, Weiterstadt, DE;
Yvonne Demel, Frankfurt, DE;
Tobias Kuhl, Hanau, DE;
Jürgen Gieshoff, Biebergemünd, DE;
Egbert Lox, Hochwaldhausen, DE;
Thomas Kreuzer, Karben, DE;
Umicore AG & Co. KG, Hanau, DE;
Abstract
The present invention relates to a method of removing nitrogen oxides from the exhaust gas of a lean-burn internal combustion engine by selective catalytic reduction (SCR) using ammonia. The exhaust gas is routed first over a platinum-containing pre-catalyst and then over an SCR catalyst. The ammonia needed for the selective catalytic reduction is added to the exhaust gas upstream of the pre-catalyst at an exhaust-gas temperature below 250° C., while it is supplied to the exhaust gas between the pre-catalyst and the SCR catalyst at an exhaust gas temperature above 150° C. By adopting this procedure, a very large temperature range for the selective catalytic reduction with high nitrogen conversion rates is obtained.