Patent ID: 8420036
Filing Date: 2013-04-16
Classification: B01D,F01N,Y02T

Abstract:
1. A method of treating exhaust from an engine, the exhaust containing NOx, the NOx comprising at least nitrogen monoxide (NO), comprising: providing an exhaust aftertreatment system having at least the following devices arranged in the following order on an exhaust line: a primary oxidation catalyst, a particulate filter, and a selective reduction catalyst (SCR); using a bypass line to divert a portion of the exhaust from the exhaust line from a point downstream the particulate filter to a point upstream the SCR; and installing a secondary oxidation catalyst on the bypass line; and providing the secondary oxidation catalyst with a reductant; and wherein an amount of reductant provided to the secondary oxidation catalyst determines an amount of NO to be generated by the secondary oxidation catalyst and returned to the exhaust line upstream the SCR.