Disclosed is a method for diagnosing a first exhaust treatment component for treatment of an exhaust gas stream comprising means for oxidizing nitric oxide into nitrogen dioxide. A first reduction catalytic converter is arranged upstream said means for oxidizing nitric oxide into nitrogen dioxide, and a second reduction catalytic converter is arranged downstream said means. A reagent is for reduction of nitrogen oxides in said first catalytic converter, and a first sensor measures an occurrence of nitrogen oxide downstream said means but upstream said second reduction catalytic converter. The method comprises: causing a supply of reagent upstream said first reduction catalytic converter to an extent exceeding the extent to which reagent is consumed by the first reduction catalytic converter, determining a first measure of the occurrence of reagent downstream said means for oxidizing, and diagnosing said means for oxidizing nitric oxide into nitrogen dioxide based on said first measure.

To provide a reducer supply device that can be made compact and has excellent maintainability. The reducer supply device includes a nozzle unit that adjusts a flow rate of a reducer which is to be supplied to a NOx purification catalyst device; and a pump unit that supplies the reducer to the nozzle unit. The nozzle unit and the pump unit are arranged at positions offset from each other in top view.

An exhaust aftertreatment system for an internal combustion engine includes an outer casing defining an exhaust flow path for exhaust gases from the internal combustion engine, a selective catalytic reduction unit provided in the exhaust flow path for reducing nitrogen oxides, a urea dosing device for adding urea to the exhaust flow upstream of the selective catalytic reduction unit, and a rotatable mixer device for mixing the urea with exhaust gases upstream of the selective catalytic reduction unit. The exhaust aftertreatment system further comprises an air inlet valve provided upstream of the mixer device for introducing air into the exhaust flow path, and an electric motor arranged for rotating the mixer device to create a suction of air into the exhaust flow path via the air inlet valve.

An exhaust system according to an exemplary embodiment of the present invention includes a nitrogen oxide storing catalytic collector connected to an exhaust line and collecting a nitrogen oxide included an exhaust gas in a first temperature or less; a first selective catalytic reducer disposed at a rear portion of the nitrogen oxide storing catalytic collector and reducing a nitrogen oxide included in the exhaust gas; and a first urea injector disposed at the front side of the nitrogen oxide storing catalytic collector and supplying a urea solution when a temperature of the nitrogen oxide exceeds the first temperature.

A method of heating an aftertreatment system includes fulfilling a vehicle drive load of a vehicle via an electrical drivetrain of a vehicle hybrid powertrain, wherein the vehicle hybrid powertrain comprises the electrical drivetrain and an internal combustion engine; while the electrical drivetrain is fulfilling the vehicle drive load, operating the internal combustion engine to generate airflow for transport of heat through the aftertreatment system; and directing a heat source to raise a temperature through a selective catalytic reduction (SCR) device of the aftertreatment system.

A device and a method for reducing carbon monoxide, hydrocarbons, nitrogen oxides and soot particles present in the exhaust gases of diesel engines are provided. The device includes 1) a diesel oxidation catalyst for the oxidation of carbon monoxide, hydrocarbons and nitrogen monoxide; 2) a first unit by means of which ammonia and/or a compound that breaks down to form ammonia can be metered into the exhaust gas that is to be purified; 3) a catalytically activated particulate filter, containing a wall-flow filter substrate comprising a catalytically active material that promotes the selective catalytic reduction of nitrogen oxides to form nitrogen; 4) a second unit by means of which ammonia and/or a compound that breaks down to form ammonia can be metered into the exhaust gas that is to be purified; as well as 5) a catalyst for the selective catalytic reduction of nitrogen oxides to form nitrogen.

The present disclosure describes methods for evaluating quality of DEF dosed to an EAS including a close coupled SCR unit a downstream SCR unit. A NOx conversion efficiency of the close coupled SCR unit and a NOx conversion efficiency of the downstream SCR unit are used to evaluate quality of DEF. In some embodiments, the NOx conversion efficiency of close coupled SCR unit is used to evaluate quality of DEF. Operation of an EAS using the results of the evaluation of quality of DEF are described.

An aftertreatment system (100) connected downstream an internal combustion engine arrangement (102) for receiving combustion gas exhausted from the internal combustion engine arrangement (102) during operation thereof, the aftertreatment system (100) comprising a primary aftertreatment system (104) comprising a first catalytic reduction arrangement (106); a secondary reduction system (108) comprising a second catalytic reduction arrangement (110).

A controller is applied to an internal combustion engine in which an electrically heated catalyst that is heated when supplied with electric power is installed in an exhaust passage. The controller is configured to perform a preheating process of warming up a first exhaust catalyst by supplying electric power to the electrically heated catalyst through control over a power supply before a start of the internal combustion engine. The controller is configured to, when an insulation resistance of the electrically heated catalyst at a start of the preheating process is lower than a threshold, perform the preheating process while decreasing a voltage supplied to the electrically heated catalyst.

An improved NO.sub.x sensor with an NH.sub.3 oxidation catalyst. A sensor module may include a support component, a NO.sub.x sensing material positioned on the support component, and an NH.sub.3 oxidation catalyst. The NH.sub.3 oxidation catalyst may be layered on top of the NO.sub.x sensing material or the NH.sub.3 oxidation catalyst may be positioned upstream of the NO.sub.x sensing material such that the NH.sub.3 oxidation catalyst selectively converts NH.sub.3 to N.sub.2 while permitting NO.sub.x through to the NO.sub.x sensing material.