Methods and systems for an aftertreatment arrangement

A method comprising:

• in response to a shutdown request for an engine, decoupling the engine from a drivetrain;
• fueling the engine;
• increasing an exhaust gas temperature to a temperature between a lower threshold temperature and an upper threshold temperature;
• regenerating only a low-temperature storing region adjacent to a high-temperature storing region of a lean NOx trap with lean exhaust gases;
• and
• shutting down the engine in response to the low-temperature storing region being regenerated.

A hybrid vehicle system comprising:

• an engine and an electric motor configured to provide motion to wheels of a drivetrain;
• an electric clutch for adjusting a coupling between the engine and the drivetrain;
• a lean NOx trap arranged in an exhaust passage fluidly coupled to the engine, the lean NOx trap comprising a low-temperature storing region configured to be regenerated at a temperature above a lower threshold temperature, further comprising a high-temperature storing region configured to be regenerated at a temperature above an upper threshold temperature;
• and
• a controller with computer-readable instructions stored on non-transitory memory thereof that when executed enable the controller to:
• actuate the electric clutch to decouple the engine in response to an engine shutdown request;
• fuel the engine;
• increase an exhaust gas temperature to a temperature between the lower threshold temperature and the upper threshold temperature;
• decrease a load of only the low-temperature storing region with lean exhaust gases;
• and
• shutdown the engine following regeneration of the low-temperature storing region.