Abstract: A method for controlling the effective heat transfer from a storage unit (1). During gas release from storage material (3) in the storage unit the storage material is heated by a heater (2). During re-saturation of the storage material (3) with gas the heater is off. Controlling of the effective heat transfer from the storage unit (1) is performed, during gas release, by ceasing convection of a convection gas and, during re-saturation, by performing or enabling convection of a convection gas to cool the storage unit (1).

Abstract: A catalyst system may include a three-way catalyst that receives exhaust gases from an engine and an ammonia slip catalyst that receives exhaust gases from the three-way catalyst. An air injection component can be configured between the three-way catalyst and the ammonia slip catalyst. A first sensor can determine first exhaust gases data and transmits that data to a controller, while a second sensor can determine second exhaust gases data and transmit that data to a controller. The controller can estimate unmeasured exhaust gases data based on the data received from the sensors and determine a setting of a component of the system and/or of the engine based on the unmeasured exhaust gases data.

Abstract: A catalyst for the selective catalytic reduction of nitrogen oxides in diesel engine exhaust gases using ammonia or a precursor compound decomposable to ammonia. The catalyst includes two superposed coatings applied to a support body, of which the first coating applied directly to the support body includes a transition metal-exchanged zeolite and/or a transition metal-exchanged zeolite-like compound, and effectively catalyzes the SCR reaction. The second coating is applied to the first coating to cover it on the exhaust gas side and prevent hydrocarbons having at least three carbon atoms present in the exhaust gas from contacting the first coating, without blocking the passage of nitrogen oxides and ammonia to the first coating. The second coating may be formed from small-pore zeolites and/or small-pore, zeolite-like compounds, and from suitable oxides, especially silicon dioxide, germanium dioxide, aluminum oxide, titanium dioxide, tin oxide, cerium oxide, zirconium dioxide and mixtures thereof.

Abstract: Method of controlling the operation of a combustion device to provide safe and reliable operation while reducing NOx emission that includes providing a flow of fuel and diluent at a determined volume ratio to a flame in the combustion device; providing a flame stability sensor to generate a measurement of a characteristic of the flame, providing a flow measurement for each of the fuel and diluent, and controlling the determined volume ratio of fuel:diluent using the measurement from the flame stability sensor and/or flow measurements. A combustion system incorporating this method also is included.

Abstract: A radiator is arranged behind an engine, a selective catalytic reduction apparatus, and a connecting pipe. A partition wall partitions first and second accommodation spaces. The engine, the selective catalytic reduction apparatus, and the connecting pipe are arranged in the first space. The radiator is arranged in the second space. A reducing agent tank is arranged behind the partition wall. A reducing ejection apparatus attached to the pipe ejects reducing agent into the pipe. A reducing agent hose connects the tank and the apparatus. The hose has a boundary portion positioned at a boundary between the first and second spaces. A height position of the boundary portion is between top and bottom sections of the connecting pipe. The boundary portion and the reducing agent ejection apparatus are arranged on a left or right side of a center line extending in a front and back direction of the partition wall.

Abstract: A system according to the principles of the present disclosure includes a rate determination module, a storage level determination module, and an air/fuel ratio control module. The rate determination module determines an ammonia generation rate in a three-way catalyst based on a reaction efficiency and a reactant level. The storage level determination module determines an ammonia storage level in a selective catalytic reduction (SCR) catalyst positioned downstream from the three-way catalyst based on the ammonia generation rate. The air/fuel ratio control module controls an air/fuel ratio of an engine based on the ammonia storage level.

Abstract: A method for operating an exhaust gas aftertreatment system is provided that comprises at least one first SCR device and at least one second SCR device. Furthermore, a dosing device for reactant for supplying the SCR devices is provided upstream of the first SCR device in the exhaust gas flow direction. In one embodiment, a target overall efficiency ?Des of the SCR devices is specified. Using modeling of the exhaust gas aftertreatment system, depending on the target overall efficiency ?Des a target value ?1,Des is determined that represents the degree of charge of the first SCR device with reactant. The dosing of the reactant is adjusted accordingly to achieve the target value ?1,Des.

Abstract: A filter for filtering particulate matter (PM) from exhaust gas emitted from a positive ignition engine or a compression ignition engine, which filter comprising a porous substrate having inlet surfaces and outlet surfaces, wherein the inlet surfaces are separated from the outlet surfaces by a porous structure containing pores of a first mean pore size, wherein the porous substrate is coated with a washcoat comprising a plurality of solid particles wherein the porous structure of the washcoated porous substrate contains pores of a second mean pore size, and wherein the second mean pore size is less than the first mean pore size.

Abstract: An exhaust system is provided. The exhaust system includes a first sensor that senses a level of nitrous oxide (NOx) in exhaust gas and generates a first sensor signal. A second sensor senses a level of ammonia (NH3) in the exhaust gas and generates a second sensor signal. A control module receives the first sensor signal and the second sensor signal, determines a desired reductant dosage based on the first sensor signal and the second sensor signal, and generates an injector control signal based on the desired reductant dosage.

Abstract: An exhaust purifying device for an internal combustion engine which can restrict an influence of a measurement error in a NOx sensor provided at the downstream side of a catalyst and can optimally maintain a NOx purifying rate. The device includes a catalytic converter carrying a selective catalytic reduction catalyst provided in an exhaust passage of the engine to selectively reduce nitrogen oxides, a urea water adding valve for adding urea water to the catalyst as a reducing agent, a NOx sensor provided at the downstream side of the catalyst, and an ECU for adjusting an addition amount of the urea water adding valve based upon output of the NOx sensor, wherein a urea water addition amount adjusting process is executed under a condition that a NOx amount to be generated in the engine increases.

Abstract: Reductant dosing systems and methods for engine exhaust aftertreatment are disclosed. The opening and closing of a metering valve in the reductant dosing system is controlled in a manner that mitigates pressure oscillations in the dosing system. The metering valve is opened in response to the dosing command exceeding a minimum threshold value and the differential pressure across the metering valve exceeding a differential pressure threshold. The metering valve is closed in response to either the differential pressure across the metering valve dropping below a differential pressure threshold or the actual dosed quantity exceeding the dosing command.

Abstract: A flow device for an exhaust treatment system includes a base and at least one flow deflector tube secured to the base. The flow deflector tube includes a flow inlet, a flow outlet, and a passage that extends through the flow deflector tube from the flow inlet to the flow outlet. The flow outlet is at an angled orientation to the flow inlet. A method of mixing reactants and exhaust in an exhaust treatment system includes the steps of injecting reactants into exhaust gases flowing through an exhaust conduit used to convey the exhaust gases from an engine. Bent tubes are disposed in the exhaust conduit and used to mix the exhaust gases and the reactants.

Abstract: An internal combustion engine operating at a lean air/fuel ratio includes a reductant injection system configured to dispense reductant into an exhaust gas feedstream upstream of a selective catalytic reduction device. The reductant injection system includes a reductant delivery system fluidly coupled to a reductant dispensing device that is configured to dispense the reductant. A method for monitoring the reductant injection system includes commanding the reductant dispensing device to dispense reductant at a prescribed reductant flowrate, controlling the reductant delivery system to a preferred operating state, monitoring operation of the reductant delivery system and estimating a reductant flowrate as a function of the monitored operation of the reductant delivery system, and diagnosing operation of the reductant injection system as a function of the prescribed reductant flowrate and the estimated reductant flowrate.

Abstract: An exhaust gas denitrifying system having a noise-reduction structure includes a reactor in which a chemical reaction that converts nitrogen oxides included in exhaust gas into nitrogen by denitrifying the nitrogen oxides using a catalyst takes place. The reactor includes a catalytic filter unit coated with a catalyst and provided with a plurality of through-holes through which exhaust gas passes; and a noise-reducing unit for removing noise from the exhaust gas denitrified by the catalytic filter unit. The reactor denitrifies the nitrogen oxides, and simultaneously reduces the noise, thus reducing the size of the exhaust gas denitrifying system.

Abstract: A device for evaporating a urea-water solution includes a delivery duct for the urea-water solution. The delivery duct extends through at least a first zone and a second zone for the introduction of heat energy. The zones can be heated separately from one another and, in the second zone, the delivery duct initially has a meandering course in a second inlet region, and thereafter has a rectilinear course. A method for evaporating a urea-water solution includes pre-heating the urea-water solution in the first zone to a temperature in a range from 100° C. to 150° C. and evaporating the urea-water solution in the second zone at a temperature in a range from 420° C. to 490° C. In particular, this significantly reduces the tendency for such an exhaust-gas-external evaporator for a urea-water solution to become blocked. A motor vehicle is also provided.

Abstract: A device (40) for reducing pollutants, in particular nitrogen oxides, in an exhaust gas flow of an internal combustion engine, includes a reducing agent (46), in particular a urea-water solution, which is stored in a storage tank (42), a metering module, in particular a nozzle (68), for injecting the reducing agent (46) into the exhaust gas flow, and a pump (56, 100) for delivering the reducing agent (46) from a suction point (62) in the storage tank (42) to the metering module via lines (58, 66). A pump (56, 100) lies beneath a reducing agent level (44) in the storage tank (42), and a non-return valve is provided.

Abstract: The invention relates to a catalytically active material for reacting nitrogen oxides with ammonia in the presence of hydrocarbons. The material consists of an inner core (1) made of a zeolite exchanged with one or more transition metals or a zeolite-like compound exchanged with one or more transition metals. The core of the catalytically active material is encased by a shell (2), which is made of one or more oxides selected from silicon dioxide, germanium dioxide, aluminum oxide, titanium oxide, tin oxide, cerium oxide, zirconium dioxide, and mixed oxides thereof.

Abstract: A supported catalyst for reduction reaction of nitrogen oxides includes a support and an silver (Ag)-based compound and aluminum fluoride which are immobilized in the support. A method for preparing the supported catalyst for reduction reaction of nitrogen oxides includes an impregnation step wherein aluminum fluoride, a hydrate or a salt thereof, and a silver (Ag)-based compound or a hydrate thereof are reacted with a support and a step of calcining the support. Nitrogen oxides in exhaust gas are removed by reacting with a reducing agent, in the presence of the supported catalyst for reduction reaction of nitrogen oxides. Wherein, the supported catalyst has an excellent nitrogen oxide removal efficiency at a practical exhaustion temperature of 270 to 400° C.

Abstract: A system and method for treating diesel exhaust in a diesel exhaust system, and specifically for improved NOx conversion efficiency during particulate filter regeneration, is disclosed. The exhaust gas treatment system includes a diesel oxidation catalyst (DOC); a diesel particulate filter (DPF) fluidly coupled to the DOC; a mixer fluidly coupled to the DOC and DPF, a thermal control device (TCD) positioned after the DPF, a NOx slip catalyst (NSC), at least one temperature sensor (TS), wherein the thermal control device reduces the temperature of the exhaust gas stream. The thermal control device used in conjunction with the NOx slip catalyst provides for improved overall exhaust system NOx conversion efficiency during active DPF regeneration.

Abstract: A selective catalytic reduction (SCR) device monitoring system includes an engine out NOx monitoring module, an SCR out NOx monitoring module configured and disposed to monitor NOx released from the SCR device, and a NOx storage model module operatively connected to the engine out NOx module and the SCR out NOx monitoring module. The NOx storage model module is configured and disposed to determine an amount of NOx stored in the SCR device. A consumed ammonia correction model module is operatively coupled to the NOx storage model module and configured and disposed to calculate a corrected consumed ammonia prediction factor.

Abstract: An exhaust gas treatment system for a diesel engine is disclosed. The exhaust gas treatment system includes a hydrocarbon selective catalytic reduction catalyst (HC-SCR) in fluid communication with a diesel engine to receive an exhaust gas flow therefrom. The system also includes a two-way catalyst in fluid communication with the HC-SCR to receive the exhaust gas flow therefrom, the two-way catalyst comprising a urea selective catalytic reduction catalyst and a diesel particulate filter (DPF).

Abstract: A mixing and/or evaporating device (12) for an exhaust system (5) of a combustion engine (1), in particular of a motor vehicle, includes a support body which encloses a cross section of the device (12) through which a flow can flow and which runs transversely to the axial direction (20) of the device (12) in the circumferential direction. The support body (19) has at least one guide blade (25, 28) which extends away transversely to the axial direction (20). An improved efficiency is obtained with the guide blade (25) having a roof-shaped profile (29), including two guide surfaces (30, 31) that are interconnected via a ridge (32) or apex.

Abstract: The invention is an exhaust gas apparatus of an internal combustion engine, in particular of an internal combustion engine with gasoline direct injection. The exhaust gas apparatus includes at least one selective catalytic converter. It is provided that a first catalytic converter is positioned upstream of the selective catalytic converter. The invention also provides a method for the purification of exhaust gas of an internal combustion engine, in an internal combustion engine with gasoline direct injection, for use in such an exhaust gas apparatus. In the method the selective catalytic converter is preceded by a first catalytic converter disposed upstream therefrom.

Abstract: An internal combustion engine system includes: an engine with a plurality of pistons housed in respective ones of a plurality of cylinders; an air intake system to provide air to the plurality of cylinders through respective ones of a plurality of intake valves; an exhaust system to release exhaust gas from the plurality of cylinders through respective one of a plurality of exhaust valves; an aftertreatment system to treat exhaust emission from the engine; at least one sensor to provide a sensor signal corresponding to an efficiency of the aftertreatment system; and a controller coupled to the at least one sensor and operable to regulate an internal exhaust gas recirculation operation in the cylinders when the aftertreatment system operates at less than a desired efficiency.

Abstract: The internal combustion engine has an upstream side NOx selective reduction catalyst and a downstream side NOx selective reduction catalyst which are arranged in an engine exhaust passage. The upstream side NOx selective reduction catalyst has a region where the NOx removal rate becomes substantially constant when the ratio of concentration of ammonia to NOx of the inflowing exhaust rises. The internal combustion engine has an operating state in that region where the ratio of concentration of ammonia to NOx is maintained. The downstream side NOx selective reduction catalyst has an ammonia oxidation ability which is larger than the upstream side NOx selective reduction catalyst.

Abstract: The present invention relates to a method for achieving reduced emissions at cold start of an internal combustion engine having an exhaust gas after treatment system comprising at least one Diesel Oxygen Catalyst (DOC), at least one Diesel Particulate Filter (DPF) and a Selective Catalytic Reduction (SCR) unit, comprising the steps of: heating the DOC prior to cold starting said internal combustion engine, starting and controlling the internal combustion engine towards low NOx emission when said DOC has reached a predetermined temperature, optimizing the fuel consumption at a given total emission level when said DPF and SCR has reached a predetermined temperature.

Abstract: A catalyst composition is provided having a zeolite material of a CHA crystal structure and a silica to alumina mole ratio (SAR) of about 10 to about 25 and preferably having a mean crystal size of at least 1.0 microns; and a non-aluminum base metal (M), wherein said zeolite material contains said base metal in a base metal to aluminum ratio (M:Al) of about 0.10 to about 0.24.

Abstract: An arrangement for injecting a reducing agent into an exhaust line of a combustion engine (1). An exhaust line (3) leads exhaust gases from the engine. A first turbine (4) is in the exhaust line (3). A second turbine (20) in the exhaust line is downstream of the first turbine (4) in the intended direction of flow in the exhaust line. An injector (19) injects reducing agent into the exhaust line (3) so that it is warmed and vaporized by the warm exhaust gases in the exhaust line (3), and an SCR catalyst (29). The injector (19) is in the exhaust line downstream of the first turbine (4) and upstream of the second turbine (20).

Abstract: An adaptive method is used for LNT desulfation and regeneration. The desulfation method involves adapting the amount of sulfur loading to trigger a desulfation event in accordance with the current adsorption capacity of the LNT. The method involves monitoring the current sulfur loading and the current LNT adsorption capacity. This data is used to calculate a loading amount “trigger”, whose value varies over the LNT lifetime. Whenever this trigger amount is reached, a desulfation event is performed. The regeneration method is similar, with the baseline data and loading threshold being determined by NOx loading rather than sulfur loading.

Abstract: An internal combustion engine, in particular a large multi-fuel diesel internal combustion engine, and includes an SCR catalytic converter that can be bypassed, and at least one control element for switching the flow in an exhaust gas line between a first position where the SCR catalytic converter is active and a second position where the SCR catalytic converter is bypassed, and at least one flow path bypassing the SCR catalytic converter.

Abstract: An engine exhaust purification device comprises: a selective reduction type NOx catalyst; an oxidation catalyst disposed on an upstream side of the NOx catalyst; a reducing agent adding device which adds an NOx reducing agent to an exhaust gas of an engine; a control device which controls the reducing agent adding device; and an NO2 ratio calculation device which estimates an NO2 ratio of the exhaust gas flowing into the NOx catalyst. The NO2 ratio of the exhaust gas flowing into the NOx catalyst is calculated by a catalytic reaction model where the oxidation reaction of NO in the oxidation catalyst is numerically formulated, and the NO2 ratio is reflected to calculate an amount of ammonia adsorbed on the NOx catalyst by a catalytic reaction model where a chemical reaction concerned with the reduction of NOx in the NOx catalyst is numerically formulated.

Abstract: Through the use transfer functions, or other modeling types, directed toward the individual operation of an engine and after-treatment subsystems, an optimizer determines the trade-offs between fuel consumption, urea consumption, and reduction of NOx and PM emissions for each component of the integrated system. Evaluation of these trade-offs permits the optimizer to dictate how each component should be controlled, or adjusted, to achieve optimal fuel (and urea) consumption while meeting the constraints bounding the solution. Response characteristics can be triggered by adjusting certain engine operating levers in order to achieve optimal performance of the integrated system.

Abstract: A method of dosing a reagent into an exhaust gas stream of an internal combustion engine having an SCR catalyst, the method comprising injecting reagent from a reagent tank into the exhaust gas stream at a position upstream of the SCR catalyst using a reagent injector in accordance with a first dosing schedule in order to remediate a predetermined proportion of NOx in the exhaust gas stream, the first dosing schedule being associated with a first range of engine operating conditions; and injecting reagent from the reagent tank into the exhaust gas stream at a position upstream of the SCR catalyst using a reagent injector in accordance with a second dosing schedule in order to enable heat transfer between the reagent injector and said injected reagent, the second dosing schedule being associated with a second range of engine operating conditions.

Abstract: Provided is an emission treatment system and method for simultaneously remediating the nitrogen oxides (NOx), particulate matter, and gaseous hydrocarbons present in diesel engine exhaust streams. The emission treatment system has an oxidation catalyst upstream of a soot filter coated with a material effective in the Selective Catalytic Reduction (SCR) of NOx by a reductant, e.g., ammonia. Also provided is a method for disposing an SCR catalyst composition on a wall flow monolith that provides adequate catalyst loading, but does not result in unsuitable back pressures in the exhaust.

Abstract: The present invention relates to an apparatus and method for vaporizing a fluid to improve performance of a selective catalytic reduction catalyst. A vaporizer including a plurality of flow channels having an increased surface area may facilitate vaporization and mixing of the fluid in, e.g., an engine exhaust or gas containing nitrous oxides. The vaporizer may be located in an exhaust system downstream of a fluid injection site and upstream of a selective catalytic reduction catalyst. The exhaust discharged from the selective catalytic reduction catalyst may have a reduced concentration of nitrogen oxides.

Abstract: System for storing an internal combustion engine exhaust gas liquid additive, the said system comprising a tank for storing the additive and an “immersed” baseplate (1) positioned through an opening made in the bottom wall of the tank, the said baseplate comprising at least one orifice through which a system for injecting the said additive into the exhaust gases can be fed, and also incorporating at least one other active component of the storage system and/or of the injection system.

Abstract: An exhaust gas treatment system for an internal combustion engine for determining a total amount of sulfur that is stored on at least one aftertreatment device is provided. The exhaust gas treatment system includes a control module that monitors operation of the internal combustion engine for an amount of fuel consumed and an amount of oil consumed by the internal combustion engine. The control module includes a sulfur adsorption module and a total sulfur storage module. The sulfur adsorption module determines a rate of sulfur adsorption in at least one aftertreatment device. The rate of sulfur adsorption is based on the amount of fuel consumed and the amount of oil consumed. The total sulfur storage module is in communication with the sulfur adsorption module. The total sulfur storage module determines the total amount of sulfur stored based on the rate of sulfur adsorption.

Abstract: [Problem] To provide a reducing agent supply apparatus that can quickly melt urea aqueous solution solidified in a reducing agent injection valve to allow early start of the injection control of urea aqueous solution, a method for controlling the reducing agent supply apparatus, and an exhaust gas purification apparatus.

Abstract: A method includes determining whether selective catalytic reduction (SCR) test conditions are present, and in response to the SCR test conditions being present, operating an SCR aftertreatment system at a number of reduced ammonia to NOx ratio (ANR) operating points. The method further includes determining a deNOx efficiency value corresponding to each of the ANR operating points. The method further includes determining a reductant correction value in response to the deNOx efficiency values corresponding to each of the ANR operating points, and providing a reductant injection command in response to the reductant correction value.

Abstract: A method of reducing nitrogen oxide includes a process of injecting a reductant including an amine compound and an exhaust gas including nitrogen oxide into a catalyst system including a silver alumina (Ag/Al2O3) catalyst.

Abstract: A method for an exhaust after treatment system of an engine including at least one selective catalyst reaction (SCR), at least one clean up catalyst downstream from the SCR, a urea injector upstream of the SCR and a first NOx sensor downstream the clean up catalyst. The method includes the steps of injecting a predetermined amount of urea by the injector, providing a second NOx sensor between the SCR and the clean up catalyst, measuring the NOx content received by the first NOx sensor, measuring the NOx content received by the second NOx sensor, comparing the first and the second NOx content with each other, and reducing the predetermined amount of urea if the first NOx sensor measures a higher NOx content than the second NOx sensor.

Abstract: A mixing device includes: an elbow pipe attached to an outlet pipe of a filter device; a straight pipe connected to a downstream side of the elbow pipe; and an injector attached to the elbow pipe and injecting a reductant aqueous solution into an inside of the elbow pipe toward the straight pipe. The elbow pipe is provided with an injector attachment to which the injector is attached with a bolt. An attachment face of the injector attachment is substantially flush with an end of an injection nozzle of the injector. The injector attachment is provided with a recess at which an end of the injection nozzle is exposed, the recess being enlarged toward the straight pipe. A heat-insulation layer located near an outer periphery of the recess is provided inside the injector attachment. An end of the bolt penetrates the injector from an outside to reach the heat-insulation layer.

Abstract: A monitoring system for a selective catalyst reduction system according to the present invention includes a selective catalyst reduction system that reacts with ammonia and reduces NOx, a first NOx sensor that is disposed upstream of the selective catalyst reduction system and measures the amount of the NOx that flows into the selective catalyst reduction system, a second NOx sensor that is disposed downstream of the selective catalyst reduction system and measures the amount of the NOx that is reduced, an injector that is disposed between the first NOx sensor and the selective catalyst reduction system and injects a urea solution, and a control portion that calculates reduction efficiency based on signals that are detected from the first NOx sensor and the second NOx sensor, determines the necessary amount of the ammonia according to the reduction efficiency, and controls the injection amount of the urea solution through the injector.

Abstract: An ash filter for a reciprocating piston internal combustion engine is disclosed. The ash filter includes a substrate, such as a honeycomb monolith substrate or a plurality of particulate substrates, and a matrix of a zeolite material disposed on the respective substrate or substrates, the matrix of the zeolite material configured to remove ash from an exhaust gas flow from a reciprocating piston internal combustion engine. An exhaust treatment system for a reciprocating piston internal combustion engine is disclosed. The exhaust treatment system includes an ash filter comprising a matrix of a first zeolite and configured to receive an exhaust gas flow from an engine; and an exhaust treatment device, the exhaust treatment device comprising a matrix of a second zeolite and configured to receive the exhaust gas flow from the ash filter.

Abstract: For an SCR system for a motor vehicle (100; 110), the vehicle including a feed device (230) to feed reducing agent from a container (205) to a dosing unit (250) for supply of reducing agent to an exhaust duct of the vehicle (100; 110); a method of controlling the dosage of the dosing unit (250) by a pressure (Pr) at which reducing agent is dosed, and/or controlling pressure (Pr) of a rotation speed (RPM) of the feed device (230). Also a computer program product with program code (P) for a computer (200; 210) for implementing the method. Also an SCR system and a motor vehicle (100, 110) equipped with the SCR system.

Abstract: A method for treating exhaust from an engine. The method includes activating an exhaust ionizer in receipt of the exhaust when temperature of a catalyst of a selective catalytic converter, which is in communication with the exhaust ionizer so as to receive exhaust from the exhaust ionizer, is equal to or above an effective temperature. The method further includes deactivating or maintaining the exhaust ionizer in a deactivated state when temperature of the catalyst is below the effective temperature.

Abstract: Systems and methods for controlling nitrous oxide emissions are described. In one particular example, nitrous oxide formed in the exhaust system of a diesel hybrid vehicle is routed through an oxidation catalyst heated by an external source such as an electric heater. Then, the catalyst is heated from the external source to reduce nitrous oxide formation within the exhaust system by increasing the catalyst temperature above a temperature range associated with nitrous oxide generation.

Abstract: Systems and method are disclosed in which a portion of an exhaust gas stream is received into an exhaust outlet flow path downstream of a first selective catalytic reduction (SCR) catalyst and upstream of a second SCR catalyst. The removed portion is treated with a diagnostic SCR catalyst element and an NH3 concentration composition of the treated removed portion is determined. The NH3 concentration is used to control injection of reductant upstream of the first SCR catalyst.

Abstract: An exhaust purification system for an internal combustion engine is provided that can steadily maintain a NOx purification rate of a selective reduction catalyst to be high without allowing the fuel economy or marketability to deteriorate. The exhaust purification system includes a NO2—NOx ratio adjustment mechanism that causes a NO2—NOx ratio to change; and a NO2—NOx ratio perturbation controller that executes NO2—NOx ratio perturbation control so that a NO2 balance of the selective reduction catalyst in a predetermined time period, with NO2 adsorption being positive and NO2 release being negative, is 0. Herein, NO2—NOx ratio perturbation control is defined as control that alternately executes NO2 increase control to cause the NO2—NOx ratio to be greater than a reference value near 0.5, and NO2 decrease control to cause the NO2—NOx ratio to be less than the reference value.

Abstract: A method of controlling a power system including an engine and an exhaust treatment system having an exhaust treatment device is disclosed. The method includes determining a catalyst parameter indicative of a conversion efficiency of the exhaust treatment device. The method further includes determining a weighted index based on the catalyst parameter. The method further includes determining a plurality of first index values. In the method, each first index value of the plurality of first index values is predicted as a function of a corresponding respective aftertreatment control strategy. The method further includes selecting an aftertreatment control strategy based on a comparison between the weighted index and each first index value of the plurality of first index values. In the method, the selected aftertreatment control strategy changes the catalyst parameter.