Abstract: An exhaust after-treatment system is described. Generally speaking, the system includes separate primary and secondary NOx reducing systems for delivering reductant (e.g. urea and ammonia) to an exhaust stream, a sensor system for determining relevant operating conditions and an electronic control module for activating the reducing systems. The two NOx reducing systems include flow control modules coupled to the electronic control module. Methods for reducing NOx in an exhaust stream are also described. Generally speaking, the methods include the steps of determining a need for NOx reduction in an exhaust stream, determining temperature of exhaust stream, and injecting at least one of a primary reductant and a secondary reductant into the exhaust stream based on the determined temperature of the exhaust stream. Typically, the primary reductant comprises urea and the secondary reductant comprises ammonia.

Abstract: An exhaust after-treatment system is described. Generally speaking, the system includes separate primary and secondary NOx reducing systems for delivering reductant (e.g. urea and ammonia) to an exhaust stream, a sensor system for determining relevant operating conditions and an electronic control module for activating the reducing systems. The two NOx reducing systems include flow control modules coupled to the electronic control module. Methods for reducing NOx in an exhaust stream are also described. Generally speaking, the methods include the steps of determining a need for NOx reduction in an exhaust stream, determining temperature of exhaust stream, and injecting at least one of a primary reductant and a secondary reductant into the exhaust stream based on the determined temperature of the exhaust stream. Typically, the primary reductant comprises urea and the secondary reductant comprises ammonia.

Abstract: A system and method for mitigating deposit of diesel emission fluid (DEF) decomposition products on interior surfaces of an internal combustion engine exhaust system (14). A processor in a controller (34) contains a model-based control algorithm (50A; 50B) for controlling DEF injection by a DEF injector (24) to mitigate deposit formation.

Abstract: A method for injecting ammonia into an exhaust gas stream downstream of a diesel engine includes providing an exhaust gas passageway (11) from the diesel engine to an ambient (14). The exhaust gas passageway (11) includes an NOx Slip Catalyst (NSC) 20 downstream of an NOx Particulate Filter (NPF) 18. The method includes emitting exhaust gas (EG) through the exhaust gas passageway (11), and selectively injecting ammonia (NH3) upstream of the NPF 18, upstream of the NSC (20), both upstream of the NPF and the NSC, or not injecting ammonia, depending on the temperature of the exhaust gas at the NPF and at the NSC.

Abstract: A method fluidly coupling components of an exhaust gas treatment system to an exhaust gas system, then injecting gaseous ammonia into the gas treatment system, beginning reaction of gaseous ammonia with exhaust gas at a temperature of less than about 180° C., preferably about 150° C., and then continuing reaction of gaseous ammonia with exhaust gas during operation of the vehicle, is disclosed. The gas treatment system includes a mixing chamber for reacting gaseous ammonia with exhaust gas to reduce NOx in the exhaust gas. Other components of the system include a diesel oxidation catalyst (DOC), a diesel particulate filter (DPF), a NOx slip catalyst (NSC) canister, wherein the DOC, DPF and NSC are all fluidly coupled together and to the mixing chamber, an injection port for adding gaseous ammonia to the mixing chamber, and a solid ammonia source for supplying gaseous ammonia to the injection port.

Abstract: A method for injecting ammonia into an exhaust gas stream downstream of a diesel engine includes providing an exhaust gas passageway (11) from the diesel engine to an ambient (14). The exhaust gas passageway (11) includes an NOx Slip Catalyst (NSC) 20 downstream of an NOx Particulate Filter (NPF) 18. The method includes emitting exhaust gas (EG) through the exhaust gas passageway (11), and selectively injecting ammonia (NH3) upstream of the NPF 18, upstream of the NSC (20), both upstream of the NPF and the NSC, or not injecting ammonia, depending on the temperature of the exhaust gas at the NPF and at the NSC.

Abstract: A blow-by treatment assembly (10) for a vehicle having an engine (22) emitting blow-by gas (18) includes a duct (16) for receiving blow-by gas from the engine. A catalyst trap (14) is disposed in fluid communication with the duct (16). The catalyst trap (14) removes hydrocarbon emissions from the blow-by gas (18). A pump (12) pumps the blow-by gas (18) through the catalyst trap (14). An outlet (32) is in fluid communication with the catalyst trap (14) for emitting the blow-by gas to either the ambient or to a tailpipe.

Abstract: A method (10) for injecting ammonia (NH3) into exhaust gas upstream of a catalyst of an aftertreatment system includes the steps of determining whether a regeneration event is imminent (14) on the basis of predetermined parameters, and determining whether dosing parameters are met (22). The method (10) further includes the steps of calculating an amount of NH3 to fill the catalyst (18) and adjusting a quantity of NH3 dosed (22) before the regeneration event occurs.

Abstract: A method (10) for injecting ammonia (NH3) into exhaust gas upstream of a catalyst of an aftertreatment system includes the steps of determining whether a regeneration event is imminent (14) on the basis of predetermined parameters, and determining whether dosing parameters are met (22). The method (10) further includes the steps of calculating an amount of NH3 to fill the catalyst (18) and adjusting a quantity of NH3 dosed (22) before the regeneration event occurs.

Abstract: A device and method for catalytic reduction of NOx in gaseous products of a combustion process before entry into the atmosphere. The gaseous and particulate products of a combustion process flow radially through a radial flow particulate filter element (24) that is effective to trap particulate matter, and are then directed axially through a collector (26). An injector (30) introduces a reductant into an axial end of the collector for entrainment with axial flow through the collector in a direction away from the injector. Flow leaving the collector is directed through an SCR catalyst (40) where catalytic reduction of NOx occurs.

Abstract: A blow-by treatment assembly (10) for a vehicle having an engine (22) emitting blow-by gas (18) includes a duct (16) for receiving blow-by gas from the engine. A catalyst trap (14) is disposed in fluid communication with the duct (16). The catalyst trap (14) removes hydrocarbon emissions from the blow-by gas (18). A pump (12) pumps the blow-by gas (18) through the catalyst trap (14). An outlet (32) is in fluid communication with the catalyst trap (14) for emitting the blow-by gas to either the ambient or to a tailpipe.

Abstract: A diesel particulate filter has a thin band of washcoated filter material either on the inlet of the upstream side or the outlet of the downstream side. The washcoating is with platinum group metals (PGM), e.g., Pt and Pd added to the surface and pore structure of a DPF. The PDF should provide comparable or improved distance between active regeneration and/or should prevent HC/CO slip during active DPF regeneration.

Abstract: A diesel exhaust after-treatment system (110, 210) for a vehicle includes a precious metal primary diesel oxidation catalyst (DOC1) and a precious metal secondary diesel oxidation catalyst (DOC2). The primary diesel oxidation catalyst (DOC1) is located on an exhaust pipe (116, 250) and in fluid communication with and between an engine (12) and an exhaust gas outlet (126, 226). The secondary diesel oxidation catalyst (DOC2) is disposed in fluid communication with the primary diesel oxidation catalyst (DOC1) on a second exhaust pipe (130, 230, 232) and in fluid communication with the engine (12). At least one valve (128, 228, 246) is disposed on the exhaust pipe (116, 216) for selectively permitting the continuous, positive flow of exhaust gas through the secondary diesel oxidation catalyst (DOC2).

Abstract: An electrically heated element within the exhaust system of a diesel engine raises the exhaust temperature sufficiently at idle or similar low exhaust flow/low exhaust temperature conditions to the point where the DOC is activated to burn fuel. As soon as the catalyst within the DOC housing is active, the DPF regeneration can be initiated. The electrically heated element can be provided within the exhaust pipe between the turbine outlet of turbocharged diesel engines and the DOC housing inlet. The electrically heated element can be powered from the engine alternator and activated when needed by the engine electronic control module.

Abstract: A compression ignition engine (10) has an EGR loop (22) that contains a metallic DOC (30) for treating recirculated exhaust gas obtained directly from cylinder exhaust through an exhaust manifold (16) before the exhaust gas passes through a cooler (26, 28) and an EGR valve (24) to an intake system (18).