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:
Aug. 21, 2012
Filed:
Jul. 07, 2008
Galen B. Fisher, Bloomfield Hills, MI (US);
Craig L. Dimaggio, Troy, MI (US);
Ken M. Rahmoeller, West Bloomfield, MI (US);
Mark C. Sellnau, Bloomfield Hills, MI (US);
Galen B. Fisher, Bloomfield Hills, MI (US);
Craig L. DiMaggio, Troy, MI (US);
Ken M. Rahmoeller, West Bloomfield, MI (US);
Mark C. Sellnau, Bloomfield Hills, MI (US);
Delphi Technologies, Inc., Troy, MI (US);
Abstract
A method and apparatus for reducing the percentage of nitrogen dioxide and nitrogen monoxide in an exhaust gas stream of an internal combustion engine, comprising the steps of injecting a hydrocarbon compound and optionally hydrogen into the exhaust gas stream; passing the exhaust gas through a first catalyst for selective reduction of a portion of the nitrogen oxides to nitrogen, ammonia, and N-containing species; passing the exhaust gas through a second catalyst for selective reduction of a portion of the nitrogen oxides with ammonia to molecular nitrogen; sensing ammonia concentration in the exhaust gas stream after passage through either or both of the first and second catalysts; and controlling by a controller in a feedback loop the injecting to an amount of hydrocarbon that will produce a predetermined concentration of ammonia and nitrogen oxides at the sensor that will lead to high NOx conversion.