This may result in a lean mixture.
The resulting lean mixture (49) is then combusted in the presence of the main mixture (72) that is also lean thereby supporting combustion of the main mixture (72).
In a lean burn mode the engine (10) is run with a lean air/fuel ratio with intermittent purge operations.
The emissions treatment system is advantageously used for the treatment of exhaust streams from lean burn engines including diesel engines and lean burn gasoline engines.
The emissions treatment system is advantageously used for the treatment of exhaust streams from lean burn engines including diesel engines, lean burn gasoline engines and locomotive engines.
Methods of treating exhaust gas from a lean burn engine and a system for the removal of pollutants from a lean burn engine exhaust gas stream containing NOx are also described.
A lean burn internal combustion engine is described having at least one cylinder.
The invention also comprises a method for purifying the exhaust gas from lean-burn engines in rich/lean and constant lean mode, in which a catalyst as defined above is used.