Patent ID: 8833062
Filing Date: 2014-09-16
Classification: B01D,F01N,F02B,Y02A,Y02T

Abstract:
1. A method comprising: (a) passing an exhaust gas from a diesel engine over an oxidation catalyst to provide an adjusted gas stream, the exhaust gas comprising a first content level by volume of NO, a first content level by volume of NO (b) passing the adjusted gas stream through a particulate trap that results in trapping at least a portion of the particulate matter on the particulate trap; (c) combusting a significant portion of the trapped particulate matter such that there is no significant accumulation of particulate matter in the particulate trap in the presence of the adjusted gas stream at a combustion temperature that is lower than the temperature necessary to combust the trapped particulate matter in the presence of the exhaust gas such that there is no significant accumulation of particulate matter in the particulate trap, to create a further adjusted gas stream comprising a third content level by volume of NO and a third content level by volume of NO (d) injecting a reductant fluid comprising urea into the further adjusted gas stream; (e) mixing the further adjusted gas stream with the injected reductant fluid to form a further adjusted gas stream mixed with reductant fluid; and (f) passing the further adjusted gas stream mixed with reductant fluid over an SCR catalyst to provide a final adjusted gas stream comprising a fourth content level by volume of NO and a fourth content level by volume of NO wherein the second content level of NO