An exhaust treatment system includes an exhaust line, a series of emission treatment units, and an electronic control unit. The series of emission treatment units includes a catalytic unit, a particulate filter unit, an oxidation catalytic unit, a hydrogen injection unit, and a Lean NOx Trap (LNT) for trapping select emissions. A method of operating an exhaust treatment system includes introducing a fuel to a combustion engine of a motor vehicle, directing emissions from the combustion engine to an exhaust line, and passing the emissions in the exhaust line through a series of emission treatment units on the exhaust line. The method further includes injecting hydrogen into the exhaust line via a hydrogen injection unit, where an amount of hydrogen gas injected from a hydrogen inlet line reduces the trapped emissions in the LNT to an inert gas.

An engine emission treatment system incudes at least one out of an air inlet dust removal system (101), a tail gas dust removal system (102), and a tail gas ozone purification system. The tail gas dust removal system (102) has an inlet of the tail gas dust removal system, an outlet of the tail gas dust removal system, and a tail gas electric field device (1021). The tail gas ozone purification system has a reaction field (202), used for mixing an ozone stream and a tail gas stream for reaction. The engine emission treatment system may effectively treat engine emissions, so as to make the engine emissions cleaner.

A method for controlling an internal combustion engine with a catalytic converter for exhaust-gas aftertreatment, comprising specification of a target fill level profile is proposed, which fluctuates between an upper threshold value and a lower threshold value, of at least one exhaust-gas component that can be stored in the catalytic converter, determination of a present fill level of the at least one exhaust-gas component in the catalytic converter on the basis of a theoretical catalytic converter model, and control of the internal combustion engine so as to generate an exhaust gas with a target concentration of the at least one exhaust-gas component such that a deviation between the present fill level and the present target fill level in accordance with the target fill level profile is reduced. A processing unit and a computer program product for carrying out a method of said type, and a vehicle which is configured for carrying out the method, are likewise proposed.

A method of reducing the emission of nitrogen oxides (NOx) during system startup of a power generating system may include igniting a combustion turbine thereby generating exhaust, supplying the exhaust to a catalyst bed comprising a selective catalytic reduction (SCR) catalyst, injecting an initial pulse of ammonia into the exhaust during a storage period such that the NOx reacts with the ammonia and is stored in the catalyst bed as ammonium nitrate (AN) during the storage period; and injecting a scheduled amount of ammonia into the exhaust during a transition period such that the stored AN is decomposed as temperatures increase and NOx is converted via standard and fast SCR reactions during the transition period.

Methods and systems are provided for an aftertreatment system. In one example, a method comprises regenerating a NO.sub.x trap during an engine shut-down event. The method further comprises reversing a direction of flow of a gas through a HP-EGR passage during the regenerating.

In a hybrid vehicle, suppression of an amount of fuel consumed for reducing NOx stored in an NSR catalyst and suppression of deterioration in exhaust gas components due to unreacted fuel flowing out from the NSR catalyst are made compatible with each other. Predetermined power source control is carried out in accompany with the execution of NOx reduction processing to supply fuel to the NSR catalyst. In the predetermined power source control, an engine rotation speed of an internal combustion engine is made to decrease or an operation of the internal combustion engine is made to stop, and an electric motor is controlled so as to compensate for required torque. Further, during a period of execution of the predetermined power source control, a lower limit value of a predetermined target SOC range for an SOC of a battery is changed to a value smaller than at times other than the period of execution of the predetermined power source control.

An internal combustion engine control device and a catalyst deterioration diagnostic method according to the present invention control the amount of fuel to be supplied to an internal combustion engine such that the air-fuel ratio of the exhaust on the downstream side of the exhaust purification catalyst is alternately switched between rich and lean, measure the oxygen storage capability of the exhaust purification catalyst during a measurement period within a reversal period of the air-fuel ratio, and diagnose deterioration of the exhaust purification catalyst based on a measurement value of the oxygen storage capability. A time point at which the output of an exhaust sensor indicates that the air-fuel ratio of the exhaust on the downstream side of the exhaust purification catalyst begins to change from a vicinity of a stoichiometric air-fuel ratio to rich or lean is set as the time of end of the measurement period.

An internal combustion engine, with an engine regulating device and an exhaust gas aftertreatment device with an SCR catalytic converter for the reduction of at least one NO.sub.x component, and with a catalytic converter regulating device, wherein the engine regulating device is prescribed a target value for an NO.sub.x mean value of the NO.sub.x component of the exhaust gases, which mean value results at an outlet point of the exhaust gas aftertreatment device in relation to a predefinable time period, and the engine regulating device is configured at least in one operating mode to continuously calculate an NO.sub.x reference value for the catalytic converter regulating device with consideration of No.sub.x components which have already been emitted and the predefined target value, which reference value is selected in such a way that the predefined target value results at the outlet point of the exhaust gas aftertreatment device at the end of the predefinable time period when the calculated NO.sub.x reference value of the catalytic converter regulating device is fed as NO.sub.x setpoint value to the regulating means.

A method for monitoring a gas sensor (14) which comprises two electrochemical measuring cells (20, 30) and which is arranged in an exhaust tract (10) of an internal combustion engine (11), wherein the sensor elements (20, 30) exhibit a substantially identical sensitivity towards a first gas component and a different sensitivity towards a second gas component and are insensitive towards further gas components. In an operating state in which an exhaust gas stream at the gas sensor (14) contains less of the second gas component than of the first gas component a concentration of the first gas component is calculated from each of the sensor signals from the sensor elements (20, 30) and a defect in a sensor element (20, 30) is deduced from the concentrations of the first gas component.

A modular exhaust subsystem for purifying an exhaust gas feedstream of a compression-ignition internal combustion engine upstream of a base exhaust aftertreatment system includes a selective catalytic reduction (SCR) catalyst, and a first exhaust gas sensor and a first temperature sensor that are arranged to monitor the SCR catalyst. A reductant delivery system is arranged to inject a reductant upstream of the SCR catalyst. A controller is in communication with an engine-out exhaust gas sensor, a second exhaust gas sensor and a second temperature sensor that are arranged to monitor the base exhaust aftertreatment system. The controller controls the reductant delivery system to inject the reductant into the exhaust gas feedstream upstream of the SCR catalyst based upon inputs from the first and second exhaust gas sensors, the engine-out exhaust gas sensor, and the first and second temperature sensors.