Abstract: A diesel engine exhaust treatment system is provided which includes a diesel oxidation catalyst and a diesel particulate filter, where a first SCR catalyst is positioned at the inlet of the diesel particulate filter, and a second SCR catalyst is coated on the filter. The first and second SCR catalysts each have a low loading, such that a lower backpressure is achieved over the use of a single SCR-coated diesel particulate filter at higher catalyst loadings. The exhaust treatment system also provides effective catalyst efficiency for removal of NOx and other gaseous emissions.

Abstract: Systems and methods for reducing NOx emissions using a branched exhaust system with a first and second turbine including an emission-control device containing a zeolite, are described. In one example approach, a method comprises: during a first duration when exhaust temperature is below a first temperature threshold, directing exhaust gas through the second turbine and the emission-control device, and adjusting the second turbine to control intake boost; and during a second duration following the first, directing exhaust gas through the first turbine, and adjusting the first turbine to control intake boost. The emission-control device may be purged when exhaust temperature is above a second temperature threshold higher than the first temperature threshold, where during the second duration exhaust gas does not flow through the emission-control device.

Abstract: One aspect of the present invention is directed to a staged catalyst system for reducing gases in the exhaust from a combustion engine. In one embodiment, the staged catalyst system includes an integrated particulate filter block supporting thereupon a first selective catalytic reduction catalyst; and a flow-through catalyst block supporting thereupon a second selective catalytic reduction catalyst, wherein the integrated particulate filter block is disposed downstream of the combustion engine and upstream of the flow-through catalyst block.

Abstract: According to one aspect of the present invention, there is provided a multi-functional catalyst block for reducing waste materials in the exhaust from a combustion engine. In one embodiment, the multi-functional catalyst block includes a substrate, a urea-hydrolyzing catalyst supported on the substrate, and a selective catalytic reduction (SCR) catalyst supported on the substrate. In another embodiment, the substrate is a wall-flow monolith configured as a particulate filter. In yet another embodiment, the substrate is a flow-through monolith.

Abstract: Methods and systems for controlling and/or diagnosing an emission control system of a vehicle having a first SCR region upstream of a second SCR region are provided herein. One exemplary method includes, indicating degradation based on a first SCR region performance during a first condition; and indicating degradation based on a second SCR region performance during a second condition, the first condition different than the second condition. In this way, different levels of degradation among different SCR regions may be used to indicate emissions levels have increased above a threshold value, for example.

Abstract: According to at least one aspect of the present invention, a urea-resistant catalytic unit is provided. In at least one embodiment, the catalytic unit includes a catalyst having a catalyst surface, and a urea-resistant coating in contact with at least a portion of the catalyst surface, wherein the urea-resistant coating effectively reduces urea-induced deactivation of the catalyst. In at least another embodiment, the urea-resistant coating includes at least one oxide from the group consisting of titanium oxide, tungsten oxide, zirconium oxide, molybdenum oxide, aluminum oxide, silicon dioxide, sulfur oxide, niobium oxide, molybdenum oxide, yttrium oxide, nickel oxide, cobalt oxide, and combinations thereof.

Abstract: The present invention relates to an emission control system for reducing gases from the exhaust of a combustion process. In at least one embodiment, the emission control system includes an exhaust passage for transporting the exhaust from the combustion process; a reductant disposed within exhaust passage downstream of the combustion process, and an integrated particulate filter and selective catalytic reduction unit disposed downstream of the reductant, with the unit having a first selective catalytic reduction catalyst disposed within a first inner wall portion of the exhaust passage; and a particulate filter disposed within a second inner wall portion of the exhaust passage downstream of the first inner wall portion. In at least one particular embodiment, the particulate fileter is coated with a second selective catalytic reduction catalyst.

Abstract: A diesel engine exhaust treatment system and method is provided which utilizes a diesel particulate filter positioned in the exhaust gas stream of a vehicle which includes an SCR catalyst, an ammonia oxidation catalyst, and/or a diesel oxidation catalyst. The system is capable of performing multiple functions including converting NOx to N2, converting HC and CO to H2O and CO2, trapping particulates, and minimizing ammonia emissions. The system is more compact and efficient than prior systems utilizing separate catalyst units, and minimizes backpressure while maximizing catalyst performance.

Abstract: Systems and methods are provided for reducing NOx emissions from a vehicle including an engine having an exhaust. In one example, the system comprises a NOx reducing system coupled to the engine exhaust including a base metal zeolite, said NOx reducing system including a first layer with a first pore size and a second layer with a second pore size, said first pore size being smaller than said second pore size.

Abstract: Systems and methods are provided for reducing NOx emissions from a vehicle including an engine having an exhaust. One example system comprises a NOx reducing system coupled to the engine exhaust, said NOx reducing system including a catalytic unit, said catalytic unit including a first zeolite catalyst with a first NOx conversion performance in a first temperature range and a second NOx conversion performance, lower than said first NOx conversion performance, in a second temperature range. The catalytic unit also comprises a second zeolite catalyst with a third NOx conversion performance, lower than said first NOx conversion performance, in the first temperature range and a fourth NOx conversion performance, higher than said second and third NOx conversion performances in the second temperature range, said first temperature range being higher than said second temperature range.

Abstract: A system for treating exhaust gases from an engine is described. The system includes, the exhaust gases routed from the engine to atmosphere through an exhaust passage, the system comprising: an injector directing a spray of reductant into the exhaust gases routed from the engine to atmosphere; an exhaust separation passage that separates an exhaust gas flow received from the engine into a plurality of separate exhaust gas flows; a plurality of oxidation catalysts, each of which receives one of the plurality of separate exhaust gas flows; a flow combining passage that receives the plurality of separate exhaust gas flows and combines them into a re-combined exhaust gas flow; a turbocharger that receives the re-combined exhaust gas flow from the flow combining passage; and a selective catalytic reduction catalyst positioned downstream of the turbocharger.

Abstract: An emission control system capable of remediating an exhaust from an internal combustion engine and having an exhaust passage, an oxidation catalyst, a reducing agent and a source of the reducing agent cooperating with an aperture in the exhaust passage. The aperture is disposed downstream of the oxidation catalyst. The system also includes a mixer arranged within the exhaust passage downstream of the aperture. The mixer includes a plurality of mixing elements. The mixer also includes a coating capable of hydrolyzing the reducing agent. At least a portion of the mixing elements which have a thermal conductivity greater than 8 W/m/° K. The system includes a selective catalytic reduction (SCR) catalyst disposed downstream from the mixer.

Abstract: A method for controlling reductant injection into an exhaust stream upstream of a catalyst coupled to an internal combustion engine is disclosed. In the method, an ammonia sensor located downstream of the exhaust catalyst is used to determine ammonia concentration in the exhaust stream. The ammonia concentration is compared to an allowable threshold and an allowable fraction, i.e., a maximum limit on a fraction of ammonia in the exhaust stream compared with the ammonia supplied by the reductant injector. Additionally, based on a NOx sensor, it is determined whether NOx conversion of the catalyst has increased in response to an increase in reductant injection. If not, reductant injection quantity is reduced.

Abstract: A system for effective NOx and particulate matter control in a diesel or other lean burn internal combustion engine is presented. The system includes a urea-based SCR catalyst having an oxidation catalyst coupled upstream of it and a particulate filter coupled downstream of the SCR catalyst. This system configuration results in improved NOx conversion due to fast SCR catalyst warm-up and higher operating temperatures. Additionally, placing the particulate filter last in this system configuration reduces tailpipe ammonia emissions as well as prevents any thermal damage to the SCR catalyst due to the particulate filter regeneration.

Abstract: A system and a method for effective NOx and particulate matter control in a diesel or other lean burn internal combustion engine is presented. The system includes a urea-based SCR catalyst having an oxidation catalyst coupled upstream of it and a particulate filter coupled downstream of the SCR catalyst. The particulate filter regeneration method teaches controlling operating conditions to bring the particulate filter temperature in the range where exothermic reaction between hydrocarbon and oxygen occurs. Once this is accomplished, extra hydrocarbons are injected into the exhaust gas entering the particulate filter where they combust and the resulting exotherm regenerates the filter. This method achieves effective particulate matter control while eliminating the risk of thermal damage to the upstream devices and minimizing regeneration fuel economy penalty.

Abstract: A method and system for freeze protecting liquid NOx reductants, preferably used in vehicle applications, wherein a liquid NOx reductant, carried onboard a vehicle exposed to cold weather conditions, is heated by existing thermal energy generated by fuel compression. The heated fuel heats a potentially frozen reductant and the liquid reductant is supplied to an exhaust gas pipe in front of a catalyst for reducing NOx on the surface of the catalyst and catalytically converted into environmentally safe nitrogen and water.

Abstract: A system and a method for effective NOx and particulate matter control in a diesel or other lean burn internal combustion engine is presented. The system includes a urea-based SCR catalyst having an oxidation catalyst coupled upstream of it and a particulate filter coupled downstream of the SCR catalyst. The particulate filter regeneration method teaches controlling operating conditions to bring the particulate filter temperature in the range where exothermic reaction between hydrocarbon and oxygen occurs. Once this is accomplished, extra hydrocarbons are injected into the exhaust gas entering the particulate filter where they combust and the resulting exotherm regenerates the filter. This method achieves effective particulate matter control while eliminating the risk of thermal damage to the upstream devices and minimizing regeneration fuel economy penalty.

Abstract: A system for effective NOx and particulate matter control in a diesel or other lean burn internal combustion engine is presented. The system includes a urea-based SCR catalyst having an oxidation catalyst coupled upstream of it and a particulate filter coupled downstream of the SCR catalyst. This system configuration results in improved NOx conversion due to fast SCR catalyst warm-up and higher operating temperatures. Additionally, placing the particulate filter last in this system configuration reduces tailpipe ammonia emissions as well as prevents any thermal damage to the SCR catalyst due to the particulate filter regeneration.

Abstract: A method and system for freeze protecting liquid NOx reductants, preferably used in vehicle applications, wherein a liquid NOx reductant, carried onboard a vehicle exposed to cold weather conditions, is heated by existing thermal energy generated by fuel compression. The heated fuel heats a potentially frozen reductant and the liquid reductant is supplied to an exhaust gas pipe in front of a catalyst for reducing NOx on the surface of the catalyst and catalytically converted into environmentally safe nitrogen and water.

Abstract: A method and system for controlling reductant injection into an exhaust stream upstream of a catalyst coupled to an internal combustion engine is disclosed. The method and system determine a reductant fraction representative of the fractional amount of the reductant used in the catalyst (i.e., the amount of reductant used in the reaction in the catalyst) and the amount of the reductant passing through the catalyst. The method and system vary the amount of reductant injection in accordance with both the determined reductant fraction and the amount of reductant passing from the catalyst.