Patent ID: 7197867

Claim:
A method for simultaneous removal of sulfur from a lean NO x trap and regeneration of a Diesel particulate filter of a Diesel engine equipped with a turbocharger, said method comprising: determining a need to reduce sulfur accumulations stored in said lean NO x trap; determining a desired rich combustion mode for temporary operation of the engine; sensing the substrate temperature of said lean NO x trap; sensing the temperature of exhaust gas prior to the exhaust gas passing through a turbine stage of said turbocharger; alternatingly operating said engine in a lean combustion mode and said desired rich combustion mode for respective predefined periods of time, said respective periods of time being of a frequency and duration sufficient to increase said substrate temperature of the lean NO x trap to a temperature at which said sulfur accumulations stored in the lean NO x trap are reduced and said Diesel particulate trap is simultaneously regenerated; and controlling air/fuel ratio and the frequency and duration of time of operation n said alternating lean and rich operating moods to prevent temperature of the exhaust gas prior to passing through the turbocharger from exceeding a predefined value.