Patent ID: 6220022
Filing Date: 2001-04-24
Classification: B01D,Y02T

Abstract:
A system for treating an exhaust gas stream from a diesel engine, the system comprising:a diesel engine which produces an exhaust gas stream;a first reducing catalyst, positioned along the exhaust gas stream at a first catalyst position, at which the exhaust gas temperature under full engine load is greater than 200.degree. C., the first reducing catalyst being provided with at least one zone having lower catalytic activity than the remainder of the catalyst, which zone permits slippage of non-converted hydrocarbons and carbon monoxide under full engine load; anda second reducing catalyst, positioned in series with the first reducing catalyst along the exhaust gas stream at a second catalyst position downstream or the first catalyst position, at which the exhaust gas temperature is within a temperature window for nitrogen oxides conversion of the second reducing catalyst under full engine load.