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:
Dec. 14, 1999
Filed:
Dec. 22, 1997
Applicant:
Inventors:
Hans Van Tillaart, Freigericht, DE;
Jurgen Leyrer, Rheinfelden, DE;
Egbert Lox, Hanau, DE;
Thomas Kreuzer, Karben, DE;
Stephan Eckhoff, Wunstorf, DE;
Assignee:
Degussa-Huls Aktiengesellschaft, Frankfurt am Main, DE;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
B01D / ; B01J / ; F01N / ; F01N / ;
U.S. Cl.
CPC ...
423212 ; 4232391 ; 4232132 ; 4232135 ; 60274 ; 60286 ; 60301 ;
Abstract
A process is disclosed for lowering nitrogen oxide levels in combustion engine exhaust gas by a reduction catalyst and by controlling the exhaust gas temperature upstream from the catalyst to a constant value, at which the catalyst exhibits maximum conversion for nitrogen oxides. It is possible to maintain maximum conversion over a wide range of engine outlet temperatures of the exhaust gas.