METHOD FOR PURIFYING THE EXHAUST GASES PRODUCED BY A COMBUSTION ENGINE WITH WHICH A MOTOR VEHICLE IS FITTED

摘要

The subject of the invention is a method for purifying the exhaust gases (3) flowing along inside an exhaust line (2) with which a motor vehicle is fitted. The exhaust line (2) comprises, in succession, a hot zone (ZC), an intermediate zone (ZI) and a cold zone (ZF). The method comprises at least the following successive operations: *) an operation of oxidizing the exhaust gases (3) which is performed in the hot zone (ZC), *) an operation of injecting a reducing agent, *) a first operation of reducing nitrogen oxides contained in the exhaust gases (3) using the reducing agent, the first reduction operation being performed in an upstream SCR element (SCR1), *) a second operation of reducing the nitrogen oxides contained in the exhaust gases (3) using the reducing agent, the second reduction operation being performed in a downstream SCR element (SCR2) positioned downstream of the upstream SCR element (SCR1) and in the cold zone (ZF).