Abstract: An exhaust aftertreatment system for purifying an exhaust gas feedstream from an internal combustion engine disposed to operate at a lean air/fuel ratio is described, and includes an oxidation catalyst disposed upstream of a low-temperature NOx adsorber. The oxidation catalyst includes a zeolite catalyst including a base metal, a noble metal, and a zeolite disposed on a substrate, and the low-temperature NOx adsorber includes a zeolite catalyst and a supported platinum group metal catalyst.

Abstract: A dual-layer catalyst includes a substrate, a first layer disposed on the substrate, and a second layer disposed on the first layer. The first layer includes a first catalyst for storing NOx when the first catalyst has a temperature below an active temperature of a second catalyst. The first catalyst is to release the stored NOx when the first catalyst is heated to the active temperature of the second catalyst. The second layer includes the second catalyst for ammonia Selective Catalytic Reduction of the released NOx. The dual-layer catalyst is to be included in a catalytic converter and a catalyst system for reducing NOx emissions from a diesel engine, the NOx emissions including NOx emitted during a predetermined cold-start time period.

Abstract: An aftertreatment system utilizes chemical reactions to treat an exhaust gas flow. A device for use within an aftertreatment system includes a silver-based NOx storage catalyst and a zeolite. The silver-based NOx storage catalyst and the zeolite store NOx through a low temperature startup period of operation. In one embodiment, the zeolite includes a barium Y zeolite.

Abstract: Nitrogen oxides (NOx), carbon monoxide (CO), and residual hydrocarbons are adsorbed and stored from a low temperature, cold-start, diesel engine (or lean-burn gasoline engine) exhaust stream by a combination of a silver-based (Ag/Al2O3) NOx adsorber material and a zeolite-platinum group metal (zeolite-PGM) adsorber material for low temperature temporary storage of the NOx. The combination of NOx adsorber materials is formed as separate washcoats on channel walls of an extruded flow-through monolithic support.

Abstract: An aftertreatment system utilizes chemical reactions to treat an exhaust gas flow. A device for use within an aftertreatment system includes a silver-based NOx storage catalyst and a zeolite. The silver-based NOx storage catalyst and the zeolite store NOx through a low temperature startup period of operation. In one embodiment, the zeolite includes a barium Y zeolite.

Abstract: Provided is an improved selective catalytic reduction filtering (SCRF) device that separates reduction of nitrogen oxides (NOx) from oxidation of soot, hydro-carbon (HC) and carbon monoxide (CO). The SCRF device has a diesel oxidation catalyst unit for oxidizing HC and CO and oxidizing diesel fuel to support DPF regenerations, and a SCR filtering unit, including at least one inlet channel and being connected to the diesel oxidation catalyst unit, for controlling (soot) emission, cleaning-up slipped HC and CO during a DPF regeneration, and reducing nitrogen oxides in the diesel exhaust gas. At least one inlet channel is coated with an ammonia-neutral oxidation catalyst, and at least one outlet channel is coated with a selected catalytic reduction catalyst.

Abstract: A method is disclosed of providing a fuel efficient regeneration of an exhaust after-treatment (AT) system that includes a lean oxides of nitrogen (NOX) trap (LNT) and a selective catalytic reduction filter (SCRF) positioned downstream of the LNT. The method includes regulating a selectable position valve. The valve permits a first gas flow portion to pass through the LNT and diverts a remaining second portion of exhaust gas flow from a first passage connecting an engine and the AT system to a second exhaust passage to thereby bypass the LNT. The method also includes regulating a first device to inject fuel into the first portion of the exhaust gas flow. The injection of fuel in to the first portion of the exhaust gas flow provides fuel efficient regeneration of the LNT and promotes NOX conversion and ammonia (NH3) formation in the LNT. A system employing the method is also disclosed.

Abstract: A method of determining aging of a diesel oxidation catalyst (DOC) in an engine exhaust system includes receiving a first sensor signal from a first nitrogen oxides (NOx) sensor positioned in exhaust flow upstream of the DOC. The first sensor signal is indicative of an amount of NOx in the exhaust flow upstream of the DOC. The method further includes receiving a second sensor signal from a second NOx sensor positioned in exhaust flow downstream of the DOC. The second sensor signal is indicative of an amount of NOx downstream of the DOC. A difference between the first sensor signal and the second sensor signal is calculated via a controller. A DOC aging level based on a predetermined correlation between the difference and DOC aging is then determined by the controller.

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 correction factor.

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 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: An exhaust gas treatment system includes a SCR device and a DOC converter disposed upstream of the SCR device. A DEF dosing system includes an injector disposed upstream of the DOC converter for injecting ammonia reductant into the flow of exhaust gas upstream of the DOC converter. The DOC converter includes a corrugated metallic substrate having an ammonia-neutral oxidation catalyst compound that is operable to oxidize hydrocarbons and carbon monoxide in the flow of exhaust gas, while not reacting with the ammonia reductant in the flow of exhaust gas. The ammonia-neutral oxidation catalyst compound allows the ammonia reductant in the flow of exhaust gas to pass through the DOC converter, for reaction with a selective catalytic reduction composition in the SCR device.

Abstract: A method of determining aging of a diesel oxidation catalyst (DOC) in an engine exhaust system includes receiving a first sensor signal from a first nitrogen oxides (NOx) sensor positioned in exhaust flow upstream of the DOC. The first sensor signal is indicative of an amount of NOx in the exhaust flow upstream of the DOC. The method further includes receiving a second sensor signal from a second NOx sensor positioned in exhaust flow downstream of the DOC. The second sensor signal is indicative of an amount of NOx downstream of the DOC. A difference between the first sensor signal and the second sensor signal is calculated via a controller. A DOC aging level based on a predetermined correlation between the difference and DOC aging is then determined by the controller.

Abstract: A method and system for determining conversion of NO to NO2 in an engine exhaust stream by an oxidation catalyst during operation of the engine is disclosed based on injecting hydrocarbon fuel into the exhaust stream upstream of the oxidation catalyst, measuring a temperature of the exhaust stream on the upstream and downstream sides of the oxidation catalyst, calculating a difference in exhaust stream temperature between the upstream and downstream sides of the oxidation catalyst, and determining the conversion of NO to NO2 by the oxidation catalyst from the difference in exhaust stream temperature based on a predetermined correlation profile between the temperatures on the upstream and downstream sides of the oxidation catalyst and conversion of NO to NO2.

Abstract: An exhaust system for an engine comprises a selective catalytic reduction (“SCR”) device having a NOx reducing selective catalytic reduction composition disposed thereon. A particulate filter is disposed in the rigid shell or canister downstream of the selective catalytic reduction device. An ammonia dosing system comprising a controller in signal communication with NOx sensors located upstream and downstream of the selective catalytic reduction device for injection of ammonia into the exhaust gas upstream of the SCR device based on information collected from the NOx sensors to thereby optimize the reduction of NOx in the exhaust gas. An ammonia-neutral oxidation catalyst compound is disposed on the wall-flow substrate of the particulate filter device and is configured to pass through ammonia constituents of the exhaust gas exiting the selective catalytic reduction device with little or no conversion of the ammonia constituents to N2, N2O and NOx.

Abstract: An emission treatment system for a vehicle having an internal combustion engine is described. The emission treatment system has an HC-SCR catalyst including a non-Pt group metal dispersed in a ceramic matrix configured to receive an exhaust gas flow from an engine. The system also has an oxidation catalyst comprising a Pt group metal configured to receive the exhaust gas flow from the HC-SCR catalyst. The system also has a U-SCR catalyst and a diesel particulate filter, one of the U-SCR catalyst or the DPF configured to receive the exhaust gas flow from the oxidation catalyst and the other one of the U-SCR catalyst or the diesel particulate filter configured to receive the exhaust gas flow from the respective one.

Abstract: An exhaust system for an engine comprises a selective catalytic reduction (“SCR”) device having a NOx reducing selective catalytic reduction composition disposed thereon. A particulate filter is disposed in the rigid shell or canister downstream of the selective catalytic reduction device. An ammonia dosing system comprising a controller in signal communication with NOx sensors located upstream and downstream of the selective catalytic reduction device for injection of ammonia into the exhaust gas upstream of the SCR device based on information collected from the NOx sensors to thereby optimize the reduction of NOx in the exhaust gas. An ammonia-neutral oxidation catalyst compound is disposed on the wall-flow substrate of the particulate filter device and is configured to pass through ammonia constituents of the exhaust gas exiting the selective catalytic reduction device with little or no conversion of the ammonia constituents to N2, N2O and NOx.

Abstract: According to one aspect of the invention, a mixer element to be placed between an internal combustion engine exhaust manifold and catalytic converter is provided. The mixer element includes a tubular conduit that receives an exhaust gas flow from the internal combustion engine, a first mixer configured to induce a first vortex of the exhaust gas flow in a first rotational direction and an injector disposed in the tubular conduit downstream of the first mixer, the injector being configured to inject a diesel emission fluid flow into the exhaust gas flow. The mixer element also includes a second mixer positioned downstream of the injector and a third mixer positioned downstream of the second mixer, the third mixer being configured to induce a second vortex of the exhaust gas flow and the diesel emission fluid mixture in a second rotational direction, opposite of the first rotational direction.

Abstract: A method and system for determining conversion of NO to NO2 in an engine exhaust stream by an oxidation catalyst during operation of the engine is disclosed based on injecting hydrocarbon fuel into the exhaust stream upstream of the oxidation catalyst, measuring a temperature of the exhaust stream on the upstream and downstream sides of the oxidation catalyst, calculating a difference in exhaust stream temperature between the upstream and downstream sides of the oxidation catalyst, and determining the conversion of NO to NO2 by the oxidation catalyst from the difference in exhaust stream temperature based on a predetermined correlation profile between the temperatures on the upstream and downstream sides of the oxidation catalyst and conversion of NO to NO2.

Abstract: An exhaust diagnostic system includes an exhaust gas temperature management module that selectively increases a temperature of a selective catalytic reduction (SCR) catalyst to a predetermined testing temperature range using an intrusive exhaust gas temperature management approach. An SCR efficiency testing module estimates an efficiency of the SCR catalyst while the temperature is within the predetermined temperature range.