Abstract: An exhaust treatment control system includes a controller configured to determine a value representative of a NO2 concentration associated with an exhaust gas upstream of a selective catalytic reduction (SCR) catalyst, and determine a value representative of a NO concentration associated with the exhaust gas upstream of the SCR catalyst. The controller can also be configured to transmit a signal to at least partially control an injection of a hydrocarbon into the exhaust gas, wherein the hydrocarbon injection can occur upstream of an oxidation catalyst to at least partially decrease the NO2 concentration of the exhaust gas downstream of the oxidation catalyst, and wherein the oxidation catalyst can be located upstream of the SCR catalyst.

Abstract: A catalytic filter system is disclosed. The catalytic filter system contains a catalyst including a ternary nitride and at least one of gold, osmium, iridium, palladium, rhodium, rhenium, ruthenium, or cesium. The catalytic filter system may further include an energy source situated to impart energy to the catalyst.

Abstract: A method for treating a flow of exhaust from an engine includes injecting reductant into the flow of exhaust with an injector disposed upstream from a catalytic device. The injector and the catalytic device are disposed in an exhaust system for the engine. The method also includes passing the flow of exhaust through the catalytic device, sensing a characteristic of at least one of the exhaust system and the engine, monitoring the sensed characteristic to recognize a condition associated with a formation of a decomposition material formed from the reductant, and controlling an operation of at least one of the engine and the exhaust system to increase a temperature in the exhaust system in response to the recognized condition.

Abstract: A catalyst is disclosed. The catalyst contains a ternary nitride and at least one of gold, osmium, iridium, palladium, rhodium, rhenium, ruthenium, or cesium. The catalyst may be used for a particulate filter in an engine exhaust treatment system.

Abstract: A first aspect of the present disclosure includes a method of controlling nitric oxides emissions. The method may include producing an exhaust gas stream containing NOx and supplying the exhaust gas stream to an exhaust passage. The method may further comprise supplying ammonia to the exhaust passage at a location upstream of a first selective catalytic reduction catalyst, wherein the amount of ammonia supplied at the first location is less than about 90% of the effective amount of ammonia needed for reduction of all NOx at the first location. Further, ammonia may be supplied to the exhaust passage at a second location downstream of the first selective catalytic reduction catalyst and upstream of a second selective catalytic reduction catalyst.

Abstract: A power system is provided having a first power source including at least one engine configured to combust a first air/fuel mixture and produce a first exhaust stream. The fuel of the first air/fuel mixture may be liquefied petroleum gas. The system also has a first exhaust passageway fluidly connected to the first power source and configured to receive the first exhaust stream. In addition, the system has a second power source including at least one engine configured to combust a second fuel/air mixture and produce a second exhaust stream. Furthermore, the system has a second exhaust passageway fluidly connected to the second power source and configured to receive the second exhaust stream.

Abstract: An exhaust treatment system is provided having a first exhaust passageway fluidly connected to an engine. A particulate filter and a selective catalytic reduction catalyst are situated within the first exhaust passageway. In addition, the system has a first oxidation catalyst located within the first exhaust passageway upstream of the particulate filter and the selective catalytic reduction catalyst. The system also has a second exhaust passageway fluidly connected to the first exhaust passageway upstream and downstream of the first oxidation catalyst. The exhaust treatment system further has a sensor configured to sense a parameter indicative of an exhaust gas temperature. Furthermore, the system has a controller configured to direct exhaust gas through the first oxidation catalyst when the exhaust gas temperature is below a threshold temperature and direct the exhaust gas through the second exhaust passageway when the exhaust gas temperature is above the threshold temperature.

Abstract: A power system is provided having a first power source including at least one engine configured to combust a first air/fuel mixture and produce a first exhaust stream. The system also has a first exhaust passageway fluidly connected to the first power source and configured to receive the first exhaust stream. In addition, the system has a second power source including at least one engine configured to combust a second fuel/air mixture and produce a second exhaust stream. Furthermore, the system has a second exhaust passageway fluidly connected to the second power source and configured to receive the second exhaust stream.

Abstract: A system is provided for monitoring exhaust gas concentrations in an exhaust stream from an engine. The system may include the exhaust system configured to carry an exhaust stream generated by the engine. The system may further include at least one sensor in communication with the exhaust stream and configured to generate an output indicative of a concentration of NOx and a concentration of at least one sulfur-containing compound in the exhaust stream. The system may further include a controller configured to selectively produce one of a rich condition and a lean condition in the exhaust stream and to determine, during the rich condition, the concentration of the at least one sulfur-containing compound in the exhaust stream based on the output from the at least one sensor and to determine, during the lean condition, the concentration of NOx in the exhaust stream based on the output from the at least one sensor.

Abstract: A power source has at least one combustion chamber, an exhaust system fluidly connected to the at least one combustion chamber and configured to receive an exhaust-gas stream, and a fuel source configured to supply fuel to the at least one combustion chamber. The power source also has an additive supply device configured to supply an ethanol additive to the at least one combustion chamber; and a selective reduction catalyst system catalyst fluidly connected to the exhaust system and configured to receive the exhaust-gas stream.

Abstract: A particulate regeneration system for an engine is disclosed. The particulate regeneration system may have a particulate filter configured to remove particulate matter from a flow of engine exhaust, and a diesel oxidation catalyst located upstream of the particulate filter to facilitate oxidation of the trapped particulate matter. The particulate regeneration system may further have a regeneration device located upstream of the diesel oxidation catalyst and configured to selectively heat the exhaust above an oxidation temperature of the trapped particulate matter, and a selective catalytic reduction device located downstream of the particulate filter to remove NOx from the engine exhaust. The particulate regeneration system may also have a controller in communication with the regeneration device and the engine. The controller may be configured to modify engine operation in response to initiation of a regeneration event.

Abstract: An engine exhaust treatment system is provided. The system may include a catalyst-based device including a catalyst configured to reduce an amount of NOx in exhaust gases produced by an engine, by using ammonia stored in the catalyst-based device. The system may also include a controller configured to control one or more operating parameters of the engine to, under predetermined operating conditions of the engine or catalyst-based device, increase an amount of NOx produced by the engine to prevent at least some of the ammonia stored in the catalyst-based device from being released from the catalyst-based device into the exhaust.

Abstract: A method of ammonia production for a selective catalytic reduction system is provided. The method includes producing an exhaust gas stream within a cylinder group, wherein the first exhaust gas stream includes NOx. The exhaust gas stream may be supplied to an exhaust passage and cooled to a predetermined temperature range, and at least a portion of the NOx within the exhaust gas stream my be converted into ammonia.

Abstract: An exhaust system for an engine is disclosed. The exhaust system may have a NOx reducer located to receive exhaust from the engine, and a bypass circuit configured to selectively pass supercharged air to the NOx reducer. The exhaust system may also have a valve disposed within the bypass circuit to regulate the flow of supercharged air, and a controller in communication with the valve. The controller may be configured to move the valve to pass the supercharged air and cool the exhaust received by the NOx reducer. The controller may also be configured to move the valve to reduce the passing of the supercharged air and remove sulfur compounds from the NOx reducer.

Abstract: An exhaust gas treatment system of an internal combustion engine includes a selective catalytic reduction catalyst fluidly connected to the internal combustion engine, an oxidation catalyst fluidly connected upstream of the selective catalytic reduction catalyst, and a particulate filter fluidly connected upstream of the selective catalytic reduction catalyst. The exhaust gas treatment system further includes a recirculation line configured to direct a portion of an exhaust flow of the internal combustion engine toward an inlet of the engine.

Abstract: An exhaust system for a combustion source is disclosed. The exhaust system may have a passageway connected to receive an exhaust flow from the combustion source, and a sensor disposed within the passageway. The sensor may generate a signal indicative of the concentration of a constituent in the exhaust flow. The exhaust system may also have a controller in communication with the sensor to receive the signal. The controller may be configured to selectively communicate a flow of calibration gas with the sensor during operation of the combustion source, and compare the signal received during the selective communication with a reference value. The controller may be further configured to adjust the sensor output in response to the comparison.

Abstract: A system of ammonia production for a selective catalytic reduction system is provided. The system includes producing an exhaust gas stream within a cylinder group, wherein the first exhaust gas stream includes NOx. The exhaust gas stream may be supplied to an exhaust passage and cooled to a predetermined temperature range, and at least a portion of the NOx within the exhaust gas stream may be converted into ammonia.

Abstract: An exhaust system for a combustion engine is disclosed. The exhaust system may have a housing connected to receive a flow of exhaust. The exhaust system may also have a first catalyst disposed within the housing to reduce the concentration of an exhaust constituent, and a second catalyst disposed within the housing downstream of the first catalyst to further reduce the concentration of the exhaust constituent. The exhaust system may further have a sensor disposed between the first and second catalysts to generate a signal indicative of the concentration of the exhaust constituent at the location between the first and second catalysts. The exhaust system may additionally have a controller in communication with the sensor to receive the signal. The controller may determine, based on the received signal, the concentration of the exhaust constituent at a location downstream of the second catalyst.

Abstract: An exhaust treatment system for a combustion source is disclosed. The exhaust treatment system may have a supply of catalyst configured to lower the combustion threshold value of an exhaust constituent, and an injector operable to selectively pass catalyst to the exhaust constituent. The exhaust treatment system may further have a controller in communication with the injector. The controller may be configured to determine a temperature of an exhaust flow, and operate the injector to pass catalyst in response to the combustion threshold value being greater than the determined temperature.