Abstract: An exhaust gas stream aftertreatment system and method achieves high efficiency NOx reduction in exhaust gas emissions by arranging a selective catalytic reduction (SCR) catalyst element upstream from a NOx adsorber catalyst. In an exemplary embodiment, a reductant is introduced into the exhaust gas stream, exposing the exhaust gas stream containing the reductant to a selective catalytic reduction (SCR) catalyst element, and exposing the exhaust gas stream that was exposed to the SCR catalyst element to a NOx adsorber catalyst element. The NOx adsorber catalyst element can be regenerated by temporarily reducing an oxygen concentration in an exhaust gas stream to reduce the ? of the exhaust gas stream. While the oxygen concentration is reduced, reductant is introduced into the exhaust gas stream at a rate that achieves a fuel-rich condition, and the fuel rich exhaust stream is exposed to the NOx adsorber catalyst element.

Abstract: According to one embodiment, an exhaust gas after-treatment apparatus includes an exhaust tube through which a main exhaust gas stream is flowable. The exhaust tube defines an exhaust flow channel. The apparatus also includes an exhaust flow segregator positioned within the exhaust tube. The exhaust flow segregator separates the exhaust flow channel into a first channel through which a first portion of the main exhaust gas stream is flowable and a second channel through which a second portion of the main exhaust gas stream is flowable. Additionally, the apparatus includes an injector coupled to the exhaust tube. The injector is communicable in reductant injecting communication with the first portion of the main exhaust gas stream flowing through the first channel. The apparatus also includes at least one exhaust gas heater communicable in heat supplying communication with the first portion of the main exhaust gas stream flowing through the first channel.

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: An apparatus, system, and method are disclosed for determining the distribution of particulate matter on a particulate filter. The apparatus, in one embodiment, determines a first distribution of particulate matter by comparing the pressure change across the particulate filter with a change in engine operating conditions. The apparatus may include an input module for receiving input corresponding to engine operating conditions and input from a differential pressure sensor and a feedback module to determine a first distribution of particulate matter. The apparatus may further include a feed forward module for determining a particulate distribution trend and a selection control module to combine the first distribution of particulate matter with the particulate distribution trend to determine a second distribution of particulate matter. The distribution may be defined as a uniform distribution factor in certain embodiments.

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: A technique is described including receiving a hydrocarbon stream, and heating the hydrocarbon stream with an exhaust steam from an internal combustion engine. This technique may include reacting the hydrocarbon stream catalytically to produce hydrogen and a modified hydrocarbon stream having a lower saturation state than the hydrocarbon stream, recovering energy from the hydrogen stream, and/or providing the modified hydrocarbon stream to a fuel supply for the internal combustion engine.

Abstract: Inhibiting uncontrolled regeneration of a particulate filter fluidly coupled to an exhaust manifold of an internal combustion engine may comprise reducing an oxygen concentration of exhaust gas supplied to the particulate filter if active regeneration of the particulate filter is in progress and rotational speed of the engine speed thereafter drops to an idle speed range from an elevated rotational speed that is greater than the idle speed range. Reducing the oxygen concentration of the exhaust gas supplied to the particulate filter may include any one or combination of reducing the oxygen concentration of intake air supplied to the intake manifold, reducing the air portion of the air-to-fuel ratio of the air-fuel mixture supplied to the engine and removing oxygen from the exhaust gas supplied to the particulate filter.

Abstract: An OBD system that diagnoses on board the condition of NOx adsorber catalysts in diesel engines and that relies on existing mass-produced exhaust gas oxygen sensor, also known as lambda sensor, technology, and the following established phenomena. In a reducing environment, typical exhaust gas oxygen (lambda) sensors have different sensitivities to various reductants, with sensitivity decreasing in this order: H2>CO>short-chain hydrocarbons>long-chain hydrocarbons. In the process of regeneration of the NOx adsorber catalyst, the original reductant may evolve into a different reductant species, e.g., via reactions such as a water-gas shift (WGS), a reforming, a partial oxidation, etc. This leads to a difference in exhaust gas oxygen sensor readings between the inlet to the catalyst and outlet from the catalyst. It has been observed in diesel engine testing that the ability of the NOx adsorber catalyst to perform such a reductant evolution is correlative to the catalyst's NOx reduction capability.

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.

Abstract: An apparatus, system, and method are disclosed for determining a regeneration cycle thermal ramp. A thermal ramp module estimates a regeneration cycle thermal ramp. A soot content module estimates a soot content for a filter. In one embodiment, an oxygen content module estimates an oxygen gas concentration for the filter. A thermal profile module calculates a thermal profile for the filter as a function of the soot content and the thermal ramp. The thermal profile module may also include the oxygen content in the thermal profile calculation. A test module modifies the regeneration cycle thermal ramp if the thermal profile exceeds a thermal threshold. In one embodiment, a communication module may communicate a warning if the thermal ramp exceeds a warning threshold.

Abstract: One embodiment is a unique system of EGR catalyzation with reduced EGR heating. Further embodiments, forms, objects, features, advantages, aspects, and benefits shall become apparent from the following description and drawings.

Abstract: A NOx adsorber catalyst may comprise a housing defining an inlet configured to receive exhaust gas produced by an internal combustion engine, an outlet and a chamber between the inlet and the outlet. A NOx adsorber element may be positioned in the chamber adjacent to the inlet. The NOx adsorber element may be configured to trap NOx in the exhaust gas during lean fuel operation of the engine, and to release the trapped NOx and reduce the released NOx to nitrogen during rich fuel operation of the engine. A hydrocarbon trap may be positioned in the chamber between the NOx adsorber element and the outlet. The hydrocarbon trap may be configured to trap hydrocarbons that travel through the NOx adsorber element during the rich fuel operation of the engine. The trapped hydrocarbons may be oxidized by oxygen present in the exhaust gas during lean fuel operation following rich fuel operation.

Abstract: A NOx adsorber catalyst may comprise a housing defining an inlet configured to receive exhaust gas produced by an internal combustion engine, an outlet and a chamber between the inlet and the outlet. A NOx adsorber element may be positioned in the chamber adjacent to the inlet. The NOx adsorber element may be configured to trap NOx in the exhaust gas during lean fuel operation of the engine, and to release the trapped NOx and reduce the released NOx to nitrogen during rich fuel operation of the engine. A hydrocarbon trap may be positioned in the chamber between the NOx adsorber element and the outlet. The hydrocarbon trap may be configured to trap hydrocarbons that travel through the NOx adsorber element during the rich fuel operation of the engine. The trapped hydrocarbons may be oxidized by oxygen present in the exhaust gas during lean fuel operation following rich fuel operation.

Abstract: Inhibiting uncontrolled regeneration of a particulate filter fluidly coupled to an exhaust manifold of an internal combustion engine may comprise reducing an oxygen concentration of exhaust gas supplied to the particulate filter if active regeneration of the particulate filter is in progress and rotational speed of the engine speed thereafter drops to an idle speed range from an elevated rotational speed that is greater than the idle speed range. Reducing the oxygen concentration of the exhaust gas supplied to the particulate filter may include any one or combination of reducing the oxygen concentration of intake air supplied to the intake manifold, reducing the air portion of the air-to-fuel ratio of the air-fuel mixture supplied to the engine and removing oxygen from the exhaust gas supplied to the particulate filter.

Abstract: An OBD system that diagnoses on board the condition of NOx adsorber catalysts in diesel engines and that relies on existing mass-produced exhaust gas oxygen sensor, also known as lambda sensor, technology, and the following established phenomena. In a reducing environment, typical exhaust gas oxygen (lambda) sensors have different sensitivities to various reductants, with sensitivity decreasing in this order: H2>CO>short-chain hydrocarbons>long-chain hydrocarbons. In the process of regeneration of the NOx adsorber catalyst, the original reductant may evolve into a different reductant species, e.g., via reactions such as a water-gas shift (WGS), a reforming, a partial oxidation, etc. This leads to a difference in exhaust gas oxygen sensor readings between the inlet to the catalyst and outlet from the catalyst. It has been observed in diesel engine testing that the ability of the NOx adsorber catalyst to perform such a reductant evolution is correlative to the catalyst's NOx reduction capability.

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: An apparatus, system, and method are disclosed for determining a regeneration cycle thermal ramp. A thermal ramp module estimates a regeneration cycle thermal ramp. A soot content module estimates a soot content for a filter. In one embodiment, an oxygen content module estimates an oxygen gas concentration for the filter. A thermal profile module calculates a thermal profile for the filter as a function of the soot content and the thermal ramp. The thermal profile module may also include the oxygen content in the thermal profile calculation. A test module modifies the regeneration cycle thermal ramp if the thermal profile exceeds a thermal threshold. In one embodiment, a communication module may communicate a warning if the thermal ramp exceeds a warning threshold.

Abstract: Mass spectrometry system for analyzing components of a gas. In accordance with one embodiment, the system includes a mass spectrometer adapted to analyze components of the gas, and an inlet capillary fluidically connected to the mass spectrometer to convey a sample of the gas to the mass spectrometer. The inlet capillary includes an inner bore with a bore wall having a catalytic coating thereon for reacting with at least one component of the sampled gas to convert the at least one component to another gas species as the sampled gas is conveyed through the inlet capillary. The mass spectrometer is adapted to analyze the converted gas species and derive information, such as quantity, of the component of sample gas that has been converted. A method of analyzing a gas is also provided.

Abstract: An apparatus, system, and method are disclosed for determining the distribution of particulate matter on a particulate filter. The apparatus, in one embodiment, determines a first distribution of particulate matter by comparing the pressure change across the particulate filter with a change in engine operating conditions. The apparatus may include an input module for receiving input corresponding to engine operating conditions and input from a differential pressure sensor and a feedback module to determine a first distribution of particulate matter. The apparatus may further include a feed forward module for determining a particulate distribution trend and a selection control module to combine the first distribution of particulate matter with the particulate distribution trend to determine a second distribution of particulate matter. The distribution may be defined as a uniform distribution factor in certain embodiments.

Abstract: Mass spectrometry system for analyzing components of a gas. In accordance with one embodiment, the system includes a mass spectrometer adapted to analyze components of the gas, and an inlet capillary fluidically connected to the mass spectrometer to convey a sample of the gas to the mass spectrometer. The inlet capillary includes an inner bore with a bore wall having a catalytic coating thereon for reacting with at least one component of the sampled gas to convert the at least one component to another gas species as the sampled gas is conveyed through the inlet capillary. The mass spectrometer is adapted to analyze the converted gas species and derive information, such as quantity, of the component of sample gas that has been converted. A method of analyzing a gas is also provided.