Abstract: An exemplary method and associated architecture for reducing NOx and particulate matter emissions in an exhaust stream may include passing the exhaust stream through a catalytic oxidation reactor; passing the exhaust stream through a two-way selective reduction catalyst particulate filter located downstream of the catalytic oxidation reactor, wherein the two-way selective reduction catalyst particulate filter may include a wall flow filter substrate having internal walls coated with a first selective catalytic reduction catalyst; and passing the exhaust stream through a catalytic reduction reactor located downstream of the two-way selective reduction catalyst particulate filter, wherein the catalytic reduction reactor may include a second selective catalytic reduction catalyst.

Abstract: One embodiment includes an oxidation catalyst assembly formed by applying a washcoat of platinum and a NOx storage material to a portion of a substrate material.

Abstract: A method for monitoring a hydrocarbon-selective catalytic reactor device of an exhaust aftertreatment system of an internal combustion engine operating lean of stoichiometry includes injecting a reductant into an exhaust gas feedstream upstream of the hydrocarbon-selective catalytic reactor device at a predetermined mass flowrate of the reductant, and determining a space velocity associated with a predetermined forward portion of the hydrocarbon-selective catalytic reactor device. When the space velocity exceeds a predetermined threshold space velocity, a temperature differential across the predetermined forward portion of the hydrocarbon-selective catalytic reactor device is determined, and a threshold temperature as a function of the space velocity and the mass flowrate of the reductant is determined.

Abstract: An exhaust gas treatment system for a diesel engine is disclosed. The exhaust gas treatment system includes a lean NOX trap (LNT) 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 LNT 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 reductant delivery system for an exhaust treatment system of an internal combustion engine is disclosed. The system includes a turbocharger fluidly coupled to, and configured to receive exhaust gas from, the internal combustion engine. An exhaust gas driven turbine wheel is disposed for rotation in a turbine housing of the turbocharger. A reductant injection device is fluid communication with the exhaust gas driven turbine wheel, a reductant tank having a reductant stored therein and a conduit system fluidly connecting the reductant tank with the reductant injection device. Reductant is delivered to the reductant injection device for delivery of the reductant to the exhaust gas driven turbine wheel.

Abstract: Exhaust emissions from a spark-ignition direct-injection engine connected to an oxidation catalytic device and a selective catalyst reduction device having a capacity to store ammonia reductant are controlled. The engine operates in a first combustion mode to generate ammonia reductant, stored on the second aftertreatment device. The engine operates lean of stoichiometry and nitrides of oxygen in the exhaust gas feedstream are reduced on the second aftertreatment device.

Abstract: A method for supplying reductant into an exhaust gas feedstream for an internal combustion engine includes storing a fuel/reductant blend in the fuel storage and delivery system, separating the reductant from the fuel/reductant blend, storing the reductant in a reductant storage tank, and injecting the reductant into the exhaust gas feedstream upstream of the aftertreatment device.

Abstract: A method for initiating a regeneration mode in selective catalytic reduction device utilizing hydrocarbons as a reductant includes monitoring a temperature within the aftertreatment system, monitoring a fuel dosing rate to the selective catalytic reduction device, monitoring an initial conversion efficiency, selecting a determined equation to estimate changes in a conversion efficiency of the selective catalytic reduction device based upon the monitored temperature and the monitored fuel dosing rate, estimating changes in the conversion efficiency based upon the determined equation and the initial conversion efficiency, and initiating a regeneration mode for the selective catalytic reduction device based upon the estimated changes in conversion efficiency.

Abstract: Where oxygenated hydrocarbons, such as ethanol, may be considered for use as a reductant to be added to diesel or gasoline engine exhaust for promoting the catalyzed reduction of NOx to N2, there is a need to continually adjust the amount of the reductant to be added as engine and catalyst operating conditions change. It is found that useful methods, to be practiced using a suitably programmed on-vehicle computer, can be based on a correlation for ethanol, or other specific reductant, with continually measured values of catalyst temperature, the oxygen and NOx contents of the exhaust, and the volumetric flow rate of the exhaust over a reduction catalyst, such as silver supported on alumina, selected for reduction of NOx to nitrogen. Effective amounts of the reductant for substantial reduction of NOx may be reliably determined using at least such parameters.

Abstract: A method for supplying reductant into an exhaust gas feedstream for an internal combustion engine includes storing a fuel/reductant blend in the fuel storage and delivery system, separating the reductant from the fuel/reductant blend, storing the reductant in a reductant storage tank, and injecting the reductant into the exhaust gas feedstream upstream of the aftertreatment device.

Abstract: A method for monitoring a hydrocarbon-selective catalytic reactor device of an exhaust aftertreatment system of an internal combustion engine operating lean of stoichiometry includes injecting a reductant into an exhaust gas feedstream upstream of the hydrocarbon-selective catalytic reactor device at a predetermined mass flowrate of the reductant, and determining a space velocity associated with a predetermined forward portion of the hydrocarbon-selective catalytic reactor device. When the space velocity exceeds a predetermined threshold space velocity, a temperature differential across the predetermined forward portion of the hydrocarbon-selective catalytic reactor device is determined, and a threshold temperature as a function of the space velocity and the mass flowrate of the reductant is determined.

Abstract: An exhaust gas treatment system for a diesel engine is disclosed. The exhaust gas treatment system includes a lean NOX trap (LNT) 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 LNT 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 reductant delivery system for an exhaust treatment system of an internal combustion engine is disclosed. The system includes a turbocharger fluidly coupled to, and configured to receive exhaust gas from, the internal combustion engine. An exhaust gas driven turbine wheel is disposed for rotation in a turbine housing of the turbocharger. A reductant injection device is fluid communication with the exhaust gas driven turbine wheel, a reductant tank having a reductant stored therein and a conduit system fluidly connecting the reductant tank with the reductant injection device. Reductant is delivered to the reductant injection device for delivery of the reductant to the exhaust gas driven turbine wheel.

Abstract: A method for initiating a regeneration mode in selective catalytic reduction device utilizing hydrocarbons as a reductant includes monitoring a temperature within the aftertreatment system, monitoring a fuel dosing rate to the selective catalytic reduction device, monitoring an initial conversion efficiency, selecting a determined equation to estimate changes in a conversion efficiency of the selective catalytic reduction device based upon the monitored temperature and the monitored fuel dosing rate, estimating changes in the conversion efficiency based upon the determined equation and the initial conversion efficiency, and initiating a regeneration mode for the selective catalytic reduction device based upon the estimated changes in conversion efficiency.

Abstract: A method of reducing NOx in a lean burn engine exhaust stream from a hydrocarbon burning engine may be first passing the exhaust stream over a thrifted diesel oxidation catalyst that substantially completes the oxidation of carbon monoxide to carbon dioxide and the oxidation of hydrocarbons (HC) to carbon dioxide and water. Next, separate additions of ozone and ammonia or urea may be introduced to the exhaust gas stream upstream of the catalytic reduction reactor at temperatures below 250 degrees Celsius. The additions of ozone and ammonia or urea modify the exhaust gas composition to improve the performance of NOx reduction catalysts in the catalytic reduction reactor. At temperatures above 250 degrees, the ozone addition may be reduced or eliminated, while the ammonia addition can be controlled as a function of the amount of NOx in the exhaust stream and the temperature of the catalytic reduction reactor.

Abstract: One embodiment includes an oxidation catalyst assembly formed by applying a washcoat of platinum and a NOx storage material to a portion of a substrate material.

Abstract: A method of reducing NOx in a lean burn engine exhaust stream from a hydrocarbon burning engine may be first passing the exhaust stream over a thrifted diesel oxidation catalyst that substantially completes the oxidation of carbon monoxide to carbon dioxide and the oxidation of hydrocarbons (HC) to carbon dioxide and water. Next, separate additions of ozone and ammonia or urea may be introduced to the exhaust gas stream upstream of the catalytic reduction reactor at temperatures below 250 degrees Celsius. The additions of ozone and ammonia or urea modify the exhaust gas composition to improve the performance of NOx reduction catalysts in the catalytic reduction reactor. At temperatures above 250 degrees, the ozone addition may be reduced or eliminated, while the ammonia addition can be controlled as a function of the amount of NOx in the exhaust stream and the temperature of the catalytic reduction reactor.

Abstract: Exhaust emissions from a spark-ignition direct-injection engine connected to an oxidation catalytic device and a selective catalyst reduction device having a capacity to store ammonia reductant are controlled. The engine operates in a first combustion mode to generate ammonia reductant, stored on the second aftertreatment device. The engine operates lean of stoichiometry and nitrides of oxygen in the exhaust gas feedstream are reduced on the second aftertreatment device.

Abstract: A selective catalytic reduction system for reducing oxides of nitrogen in the exhaust gas flow of an internal combustion engine is disclosed. The system has a ceramic monolith disposed within said exhaust gas flow and includes exhaust flow passages extending therethrough. A high temperature selective catalytic reduction catalyst composition is applied to an inlet portion of the exhaust flow passages and a low temperature selective catalytic reduction catalyst composition applied to an outlet portion of the exhaust flow passages. The high and the low temperature catalytic reduction catalysts are operable to reduce oxides of nitrogen at high load and low load operation of the internal combustion engine.

Abstract: An exemplary method and associated architecture for reducing NOx and particulate matter emissions in an exhaust stream may include passing the exhaust stream through a catalytic oxidation reactor; passing the exhaust stream through a two-way selective reduction catalyst particulate filter located downstream of the catalytic oxidation reactor, wherein the two-way selective reduction catalyst particulate filter may include a wall flow filter substrate having internal walls coated with a first selective catalytic reduction catalyst; and passing the exhaust stream through a catalytic reduction reactor located downstream of the two-way selective reduction catalyst particulate filter, wherein the catalytic reduction reactor may include a second selective catalytic reduction catalyst.