Abstract: Methods and systems for reducing emissions of an internal combustion engine are described. In one example, an electric heater and a selective reduction catalyst are positioned in a passage downstream of a combustor where urea may be injected to the selective reduction catalyst to reduce NOx emissions that may be generated by the combustor.

Abstract: Methods and systems for reducing emissions of an internal combustion engine are described. In one example, a combustor is applied post shutdown to purge stored NOx from a passive NOx absorber to prepare for a subsequent engine start. The trapped NOx is subsequently reduced via a selective catalytic reduction catalyst.

Abstract: Methods and systems for reducing emissions of an internal combustion engine are described. In one example, an electric heater and a passive NOx absorber or other emissions control device are positioned in a passage downstream of a combustor so as to process emissions from the combustor before an engine is started.

Abstract: Methods and systems for improving NOx conversion efficiency of a selective catalytic reduction catalyst are described. In one example, an amount of NH3 stored in a SCR is adjusted after stopping an engine so that a desired amount of NH3 may be stored within the SCR when the engine is restarted.

Abstract: Methods and systems are provided for controlling a catalyst temperature. In one example, a method includes throttling in response to the catalyst temperature exceeding a threshold temperature. The throttling includes adjusting an intake throttle position to a more closed position. The throttling further includes increasing a turbine work extraction via adjusting a position of a plurality of turbine vanes to decrease a turbine outlet temperature.

Abstract: Methods and systems are provided for a turbocharger. In one example, a method may include bypassing exhaust gases flowing to the turbocharger in response to a catalyst temperature being less than a threshold temperature. The bypassing includes opening a bypass valve and adjusting a position of one or more turbine nozzle vanes.

Abstract: Methods and systems are provided for a turbocharger. In one example, a method may include bypassing exhaust gases flowing to the turbocharger in response to a catalyst temperature being less than a threshold temperature. The bypassing includes opening a bypass valve and adjusting a position of one or more turbine nozzle vanes.

Abstract: Methods and systems are provided for heating a catalyst via a catalyst heater are presented. In one example, the catalyst may be heated to provide a minimum amount of time for the catalyst to reach a threshold temperature. In another example, the catalyst heater may be heated to minimize an amount of power that is used to heat the catalyst.

Abstract: Methods and systems are provided for fuel post injection for diesel particulate filter (DPF) regeneration. In one example, a method may include, responsive to a request for generating exotherms in an exhaust system of an engine while combustion is discontinued in at least one cylinder of the engine, injecting fuel into a cylinder within a threshold crank angle range around top dead center (TDC) of a compression stroke of the cylinder and also within the threshold crank angle range around top dead center of an exhaust stroke of the cylinder, the threshold crank angle range extending from no more than 40 crank angle degrees before TDC to no more than 40 crank angle degrees after TDC. In this way, fuel post injections may be injected +/?40 crank angle degrees after TDC of the compression and exhaust strokes to increase exhaust temperature while avoiding wall wetting and oil-in-fuel dilution.

Abstract: Methods and systems are provided for fuel post injection for diesel particulate filter (DPF) regeneration. In one example, a method may include, responsive to a request for generating exotherms in an exhaust system of an engine while combustion is discontinued in at least one cylinder of the engine, injecting fuel into a cylinder within a threshold crank angle range around top dead center (TDC) of a compression stroke of the cylinder and also within the threshold crank angle range around top dead center of an exhaust stroke of the cylinder, the threshold crank angle range extending from no more than 40 crank angle degrees before TDC to no more than 40 crank angle degrees after TDC. In this way, fuel post injections may be injected +/?40 crank angle degrees after TDC of the compression and exhaust strokes to increase exhaust temperature while avoiding wall wetting and oil-in-fuel dilution.

Abstract: Methods and systems are provided for expediting heating of an engine and an emissions device upon cold startup of the engine. In one example, a method may include prior to cold startup of an engine, operating an e-compressor and opening a recirculation valve of a recirculation passage coupled across the e-compressor to flow compressed intake air from an outlet of the e-compressor through the recirculation passage to an inlet of the e-compressor and starting the engine upon a temperature at the outlet of the e-compressor reaching a threshold and continuing to operate the e-compressor while the engine is on. The heated intake air resulting from the flow of compressed intake air through the recirculation passage raises a temperature of combustion and a temperature of exhaust gas, which may decrease catalyst light-off time of the emissions device.

Abstract: Methods and systems are provided for expediting heating of an engine and an emissions device upon cold startup of the engine. In one example, a method may include prior to cold startup of an engine, operating an e-compressor and opening a recirculation valve of a recirculation passage coupled across the e-compressor to flow compressed intake air from an outlet of the e-compressor through the recirculation passage to an inlet of the e-compressor and starting the engine upon a temperature at the outlet of the e-compressor reaching a threshold and continuing to operate the e-compressor while the engine is on. The heated intake air resulting from the flow of compressed intake air through the recirculation passage raises a temperature of combustion and a temperature of exhaust gas, which may decrease catalyst light-off time of the emissions device.