Abstract: An exhaust aftertreatment process including providing a selective catalytic reduction (SCR) catalyst disposed in an exhaust stream of an internal combustion engine; determining that a temperature of the exhaust stream is not within an NH3 based SCR range; and providing an amount of unburned hydrocarbon (UHC) to the SCR catalyst in response to the temperature of the exhaust stream not being within an NH3 based SCR range.

Abstract: According to one embodiment, an apparatus for evaluating the condition of a NOx adsorber catalyst (NAC) of an internal combustion engine system includes a rich condition timing module, NAC outlet lambda module, and NAC condition module. The rich condition timing module is configured to accumulate the total time during which exhaust gas exiting the NAC has a lambda value less than 1.0. The NAC outlet lambda module is configured to store NAC outlet lambda values of the exhaust gas while the exhaust gas exiting the NAC has a lambda value less than 1.0. The NAC condition module is configured to evaluate the condition of the NAC based on the total time during which exhaust gas exiting the NAC has a lambda value less than 1.0 and an accumulation of the stored NAC outlet lambda values.

Abstract: A system is described for producing an elevated exhaust temperature and reduced NOx output for an engine. The system includes an internal combustion engine having a common rail fuel system, an exhaust pressure modulation device for the internal combustion engine, and a controller structured to functionally execute operations for elevating the exhaust temperature and reducing the NOx output. The controller determines a desired engine outlet exhaust temperature, an engine speed, and an engine load. In response to the desired engine outlet exhaust gas temperature, the engine speed, and the engine load, the controller determines an exhaust pressure increase command and a fuel injection command including at least one post-injection event. The common rail fuel system is responsive to the fuel injection command, and the exhaust pressure modulation device is responsive to the exhaust pressure increase command.

Abstract: An aftertreatment system including a method which provides a selective catalytic reduction (SCR) catalyst disposed in an exhaust stream of an engine; determines that an ammonia pre-load condition for the SCR catalyst is present; determines a first amount of ammonia pre-load in response to the ammonia pre-load condition; injects an amount of ammonia or urea into the exhaust stream in response to the first amount of ammonia; and adsorbs a second amount of ammonia onto the SCR catalyst in response to injecting an amount of ammonia or urea, where the second amount of ammonia is either the injected amount of ammonia or an amount of ammonia resulting from hydrolysis from the injected amount of urea.

Abstract: An aftertreatment system including a method which provides a selective catalytic reduction (SCR) catalyst disposed in an exhaust stream of an engine; determines that an ammonia pre-load condition for the SCR catalyst is present; determines a first amount of ammonia pre-load in response to the ammonia pre-load condition; injects an amount of ammonia or urea into the exhaust stream in response to the first amount of ammonia; and adsorbs a second amount of ammonia onto the SCR catalyst in response to injecting an amount of ammonia or urea, where the second amount of ammonia is either the injected amount of ammonia or an amount of ammonia resulting from hydrolysis from the injected amount of urea.

Abstract: An internal combustion engine system includes a spark-ignited internal combustion engine powered by a gaseous fuel. The engine system also includes an air intake in air providing communication with the internal combustion engine. Further, the engine system includes an exhaust system in exhaust gas receiving communication with the internal combustion engine. The exhaust system includes a methane oxidation catalyst through which at least a portion of the exhaust gas flows and an exhaust gas recirculation line in exhaust gas providing communication with the air intake.

Abstract: System and methods for reducing secondary emissions in an exhaust stream from an internal combustion engine are disclosed. The systems and methods include a filtration device positioned downstream from an SCR catalyst of an aftertreatment system disposed in the exhaust system. The filtration device can also be used for particulate filter diagnostics and for treatment of ammonia slip.

Abstract: One embodiment is a method including operating an SCR system at a plurality of commanded ammonia to NOx input ratios, providing a plurality of data indicating NOx output from the SCR system for the plurality of commanded ammonia to NOx input ratios, and evaluating the plurality of data to diagnose the SCR system. Additional embodiment are methods, systems, and apparatuses including SCR diagnostics. Further embodiments, forms, objects, features, advantages, aspects, and benefits shall become apparent from the following description and drawings.

Abstract: A system is provided for enhancing aftertreatment regeneration capability. The system includes an internal combustion engine producing an exhaust gas stream and an aftertreatment component that treats the exhaust gas stream, where the aftertreatment component includes a desired inlet exhaust gas temperature. The system includes an exhaust gas pressure device that modulates an exhaust pressure value, and a fuel injection system that provides a post-injection event. The system includes a controller that provides an exhaust pressure command and a fuel injection command in response to determining that a temperature of the exhaust gas stream is lower than the desired inlet exhaust gas temperature. The exhaust gas pressure device is responsive to the exhaust pressure command and the fuel injection system is responsive to the fuel injection command.

Abstract: A system and method includes an exhaust aftertreatment system for an internal combustion engine having a reductant stored in a solid storage media. The reductant is released by heating the solid storage media to convert the reductant to gaseous form. The system and method determines the quality of the solid storage media by measuring operating parameters of the aftertreatment system and comparing the operating parameters to expected parameters stored in a memory of a controller of the system.

Abstract: Some exemplary embodiments include hybrid vehicle systems including an engine operable to output exhaust, an exhaust aftertreatment system configured to receive the exhaust from the engine, the exhaust aftertreatment system including an SCR catalyst operable to reduce NOx in the exhaust and an electrical heater operable to heat the SCR catalyst, a motor/generator operable in a braking mode to receive torque to slow the vehicle and output electrical power, an energy storage device operable to output electrical power to drive the motor/generator and receive electrical power from the motor/generator, and a controller operable to control the electrical heater to heat the SCR catalyst using electrical power from the motor/generator in the braking mode.

Abstract: According to one embodiment, an apparatus for evaluating the condition of a NOx adsorber catalyst (NAC) of an internal combustion engine system includes a rich condition timing module, NAC outlet lambda module, and NAC condition module. The rich condition timing module is configured to accumulate the total time during which exhaust gas exiting the NAC has a lambda value less than 1.0. The NAC outlet lambda module is configured to store NAC outlet lambda values of the exhaust gas while the exhaust gas exiting the NAC has a lambda value less than 1.0. The NAC condition module is configured to evaluate the condition of the NAC based on the total time during which exhaust gas exiting the NAC has a lambda value less than 1.0 and an accumulation of the stored NAC outlet lambda values.

Abstract: An example method includes determining that a selective catalytic reduction (SCR) component having a zeolite-based catalyst is contaminated with platinum (Pt). The method further includes elevating the temperature of the SCR component to at least 600° C. in response to the determining the catalytic component is contaminated with Pt, and maintaining the elevated temperature of the catalytic component for a predetermined time period thereby restoring reduction activity of the catalyst.

Abstract: According to one representative embodiment, an apparatus for reducing NOx emissions in an engine exhaust gas stream of an engine system having a selective catalytic reduction (SCR) system with an SCR catalyst positioned downstream of a reductant injector includes a NOx reduction target module and a reductant module. The NOx reduction target module is configured to determine a NOx reduction requirement, which includes an amount of NOx in the exhaust gas stream to be reduced on the SCR catalyst. The reductant module is configured to determine the amount of reductant added to the exhaust gas stream to achieve the NOx reduction requirement. The amount of reductant added to the exhaust gas stream is a function of at least one ammonia storage characteristic of the SCR catalyst, at least one reductant-to-ammonia conversion characteristic, and a conversion capability of an AMOX catalyst in exhaust receiving communication with the SCR catalyst.

Abstract: An internal combustion engine including a two-stage turbocharger configuration is described. Located between the turbines of the two-stage turbocharger may be an oxidation catalyst and a passive NOx adsorber or an oxidation catalyst and an SCR device. An exhaust path extending from an engine body of the internal combustion engine to the second turbine of the two-stage turbocharger configuration may also include one or more hydrocarbon sources or one or more ammonia sources. A bypass valve arrangement may permit decreased flow through the first stage of the two-stage turbocharger arrangement as well as one or more of the elements positioned between the turbines of the two-stage turbocharger.

Abstract: A system and method for diagnosing operation of a NOx adsorber catalyst are disclosed. An operating temperature of the catalyst is monitored, and when it exceeds a catalyst desulfation temperature threshold that occurs when the catalyst undergoes a desulfation event, a control circuit determines an oxygen storage capacity of the catalyst as a function of at least an oxygen concentration of exhaust gas exiting the catalyst. The control circuit may further determine the oxygen storage capacity as a function of an oxygen concentration of exhaust gas entering the catalyst. The control circuit may further determine the oxygen storage capacity as a function of a mass flow rate of fresh air entering the internal combustion engine that produces the exhaust gas. The oxygen storage capacity may be mapped to catalyst aging information such as, for example, a remaining useful life of the catalyst.

Abstract: Some exemplary embodiments include hybrid vehicle systems including an engine operable to output exhaust, an exhaust aftertreatment system configured to receive the exhaust from the engine, the exhaust aftertreatment system including an SCR catalyst operable to reduce NOx in the exhaust and an electrical heater operable to heat the SCR catalyst, a motor/generator operable in a braking mode to receive torque to slow the vehicle and output electrical power, an energy storage device operable to output electrical power to drive the motor/generator and receive electrical power from the motor/generator, and a controller operable to control the electrical heater to heat the SCR catalyst using electrical power from the motor/generator in the braking mode.

Abstract: A system includes an internal combustion engine producing exhaust gases as a byproduct of operation and an aftertreatment system that treats the exhaust gases. The system further includes a controller that is structured to functionally execute operations to enhance the temperature of the aftertreatment system. The controller includes an operating condition monitoring module that interprets a temperature value at a position upstream of a catalyst positioned in the aftertreatment system. The controller further includes an operating condition management module that interprets a threshold temperature value, and an engine management module that provides an engine operation command to continue engine operation in response to the temperature value being at least equal to the threshold temperature value.

Abstract: A method includes providing a system having a fluid flow, a fuel injector and an oxygen sensor disposed in the fluid flow, where the oxygen sensor is downstream of the fuel injector. The method includes determining a first air fuel ratio, changing an injection rate of the fuel injector and determining a second air fuel ratio, and determining a fault value for the fuel injector from the first air fuel ratio and the second air fuel ratio. The method further includes determining the fault value for the fuel injector by determining a difference between the first air fuel ratio and the second air fuel ratio, and by determining that the fault value is positive in response to the difference being lower than a passing threshold value. The method includes changing injection rates of the fuel injector for specified periods of time short enough to significant disruption of system temperatures.

Abstract: According to one representative embodiment, an apparatus for determining the degradation of a selective catalytic reduction (SCR) catalyst of an engine exhaust aftertreatment system includes a system properties module configured to store at least one system dynamics property value of the exhaust system at a first time and receive the at least one system dynamics property value of the exhaust aftertreatment system at a second time subsequent to the first time. The apparatus also includes a system dynamics module configured to determine a storage capacity of the SCR catalyst based on a comparison between the at least one system dynamic property value at the first time and the at least one system dynamic property value at the second time. Additionally, the apparatus includes an SCR catalyst degradation factor module configured to determine an SCR catalyst degradation factor based at least partially on the storage capacity of the SCR catalyst.