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:
Jul. 21, 2009
Filed:
Jun. 06, 2006
Jiyang Yan, Troy, MI (US);
Jiyang Yan, Troy, MI (US);
Eaton Corporation, Cleveland, OH (US);
Abstract
An exhaust aftertreatment system including a lean NOx trap, an ammonia-SCR catalyst, and an additional catalyst configured in between. The lean NOx trap adsorbs NOx from lean exhaust and produces ammonia during regeneration. The SCR catalyst adsorbs most of that ammonia and subsequently uses that ammonia to reduce NOx. The additional catalyst is adapted to reduce the concentration of hydrocarbons in the exhaust during LNT regeneration and thereby mitigate hydrocarbon poisoning of the SCR. In one embodiment, the additional catalyst is a hydrocarbon-SCR catalyst. In another embodiment, the additional catalyst is an oxidation Catalyst. In a further embodiment, the additional catalyst is a hydrocarbon adsorbent. An oxidation catalyst can be made to store oxygen for hydrocarbon oxidation while avoiding excessive oxidation of ammonia by appropriately limiting that oxygen storage capacity.