Patent ID: 7767176
Filing Date: 2010-08-03
Classification: B01D,B01J,F01N,Y02T

Abstract:
1. A method for reducing NOx emissions in the exhaust stream produced from an internal combustion engine, the method comprising: (a) metering at periodic intervals ammonia or an ammonia precursor into the exhaust stream; (b) passing the exhaust stream through a first substrate comprising a SCR catalyst composition; wherein the first substrate has an inlet end, an outlet end, a length extending between the inlet end to the outlet end, wall elements and a plurality of passages defined by the wall elements; wherein said SCR catalyst composition is disposed on the wall elements from the inlet end toward the outlet end to a length that is less than the substrate's axial length to form an inlet zone; wherein the NH wherein there is from 0.1 to 10 g/ft