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:
Sep. 07, 2010
Filed:
Mar. 02, 2009
Jong H. Lee, Rochester Hills, MI (US);
Byong Kwon Cho, Rochester Hills, MI (US);
Jong H. Lee, Rochester Hills, MI (US);
Byong Kwon Cho, Rochester Hills, MI (US);
GM Global Technology Operations, Inc., Detroit, MI (US);
Abstract
A method of reducing NOin a lean burn engine exhaust stream from a hydrocarbon burning engine may be first passing the exhaust stream over a thrifted diesel oxidation catalyst that substantially completes the oxidation of carbon monoxide to carbon dioxide and the oxidation of hydrocarbons (HC) to carbon dioxide and water. Next, separate additions of ozone and ammonia or urea may be introduced to the exhaust gas stream upstream of the catalytic reduction reactor at temperatures below 250 degrees Celsius. The additions of ozone and ammonia or urea modify the exhaust gas composition to improve the performance of NOreduction catalysts in the catalytic reduction reactor. At temperatures above 250 degrees, the ozone addition may be reduced or eliminated, while the ammonia addition can be controlled as a function of the amount of NOx in the exhaust stream and the temperature of the catalytic reduction reactor.