The present invention relates to a method for adaption of an exhaust treatment system arranged for treating an exhaust stream produced by an engine, where the exhaust treatment system includes at least a first additive dosage device, a first selective catalytic reduction catalyst arranged downstream of the first additive dosage device, a second additive dosage device arranged downstream of the first selective catalytic reduction catalyst, and a second selective catalytic reduction catalyst arranged downstream of the second additive dosage device. The method includes initiating an adaption of the second selective catalytic reduction catalyst, and controlling, during the adaption of the second selective catalytic reduction catalyst, the first additive dosage device to inject additive in accordance with at least one injection rule being designed for the adaption.

A filtration assembly for removing particulate matter from exhaust gas produced by an engine, including: a first filter; a second filter positioned downstream of the first filter; and a valve including: a first ring defining a plurality of first openings, and a second ring defining a plurality of second openings, the second ring abutting the first ring. The valve is moveable between a closed position in which the plurality of first openings are misaligned with the plurality of second openings to prevent a fluid from flowing through the plurality of first and second openings, and an open position in which the second ring is rotated relative to the first ring such that the plurality of first openings are aligned with the plurality of second openings allowing the fluid to flow therethrough. A first end of the valve is positioned at an outlet of the first filter, and a second end of the valve is positioned at an inlet of the second filter. In the closed position of the valve, substantially all of the exhaust gas flows through the second filter, and in the open position of the valve, at least a portion of the exhaust gas flows through the valve and bypasses the second filter.

An oxidation catalyst composition is provided, the composition including a plurality of platinum group metal particles having a multi-modal distribution of particle sizes. The plurality of platinum group metal particles includes a first population of platinum group metal particles having a range of particle sizes of from about 0.5 nm to about 3 nm, and a second population of platinum group metal particles having a range of particle sizes of from about 4 nm to about 15 nm. Methods for the preparation and use of the catalyst composition are also provided, as well as catalyst articles and emission gas treatment systems employing such catalyst articles. The catalyst exhibits enhanced stability with respect to oxidation performance after degreening and/or aging, as compared to conventional oxidation catalysts, in particular less loss of NOx oxidation performance.

The present disclosure is directed to an emission treatment system for NO.sub.x abatement in an exhaust stream of a lean burn engine. The emission treatment system includes a lean NO.sub.x trap (LNT) in fluid communication with and downstream from the lean burn engine and a low-temperature NO.sub.x adsorber (LT-NA) in fluid communication with and downstream of the LNT. Further provided is a method for abating NO.sub.x in an exhaust stream from a lean burn engine utilizing the disclosed system.

A controller for controlling regeneration of a selective catalytic reduction (SCR) catalyst of an aftertreatment system is configured to cause increase in a SCR catalyst temperature of the SCR catalyst to a first regeneration temperature, the first regeneration temperature being lower than a high regeneration temperature that is equal to or greater than 500 degrees Celsius. The controller is configured to determine an amount of ammonia slip downstream of the SCR catalyst; and cause an increase in the SCR catalyst temperature to a second regeneration temperature greater than the first regeneration temperature but lower than the high regeneration temperature based on the determined amount of ammonia slip.

An exhaust gas sample collector includes a tubular body, a plurality of inlet openings circumferentially spaced about an outer periphery of the tubular body, the plurality of inlet openings configured to receive exhaust gas, an outlet in fluid communication with the plurality of inlet openings, and a sensor configured to measure a characteristic of the exhaust gas at the outlet.

The present invention relates to an exhaust gas treatment system for treating exhaust gas from a lean burn combustion engine, wherein said exhaust gas comprises hydrocarbons and NOx, the exhaust gas treatment system comprising: (i) a means for injecting hydrocarbons into an exhaust gas stream; (ii) a diesel oxidation catalyst (DOC) comprising a substrate and a catalyst coating provided on the substrate, wherein the catalyst coating comprises one or more platinum group metals, wherein the one or more platinum group metals comprise platinum; (iii) a means for injecting a nitrogenous reducing agent into an exhaust gas stream; and (iv) a multifunctional catalyst (MFC) comprising an oxidation catalyst, and a selective catalytic reduction (SCR) catalyst for the selective catalytic reduction of NOx, wherein the MFC comprises a substrate and a catalyst coating provided on the substrate, wherein the catalyst coating comprises the oxidation catalyst and the SCR catalyst, wherein the oxidation catalyst comprises one or more platinum group metals, wherein the one or more platinum group metals comprise palladium and/or platinum, and wherein the SCR catalyst comprises a zeolitic material loaded with copper and/or iron; wherein the means for injecting hydrocarbons, the DOC, the means for injecting a nitrogenous reducing agent, and the MFC are located in sequential order in a conduit for exhaust gas, wherein the means for injecting hydrocarbons into an exhaust gas stream is located upstream of the DOC, wherein the DOC is located upstream of the MFC, and wherein the means for injecting a nitrogenous reducing agent into the exhaust gas stream is located between the DOC and the MFC. Furthermore, the present invention relates to a method for the treatment of exhaust gas using the exhaust gas treatment system according to the present invention, and to a method for the preparation of an exhaust gas treatment system according to the present invention.

A system for removing methane oxidation catalyst (MOC) poisons from an exhaust gas including a methane abatement unit that may receive the exhaust gas having methane (CH.sub.4)and the MOC poisons. The methane abatement unit includes a guard bed that may remove the MOC poisons from the exhaust gas and may generate an intermediate exhaust gas having the CH.sub.4 and devoid of the MOC poisons. The guard bed includes a MOC poisons capturing component having a first transition metal oxide, an aluminum oxide (Al.sub.2O.sub.3) support material, and a dolomite-derived support material. The methane abatement unit also includes a MOC bed fluidly coupled to and positioned downstream from the guard bed. The MOC bed includes a MOC and may remove CH.sub.4 from the intermediate exhaust gas to generate a treated exhaust gas having less than approximately 200 parts per million volume (ppmv) CH.sub.4.

The present disclosure provides SCR catalyst compositions capable of reducing nitrogen oxide (NO.sub.x) emissions in engine exhaust. The catalyst compositions include a reducible metal oxide support containing ceria, one or more transition metal oxides as a redox promotor; and an oxide of niobium, tungsten, silicon, molybdenum, or a combination thereof as an acidic promotor. The redox promotor and the acid promotor are both supported on the reducible metal oxide support. Further provided are SCR catalyst articles coated with such compositions, processes for preparing such catalyst compositions and articles, an exhaust gas treatment system including such catalyst articles, and methods for reducing NO.sub.x in an exhaust gas stream using such catalyst articles and systems.

An aftertreatment system for reducing constituents of an exhaust gas having a sulfur content includes: an oxidation catalyst; a filter disposed downstream of the oxidation catalyst; and a controller configured, in response to determining that the filter is to be regenerated and a desulfation condition being satisfied, to: cause a temperature of the oxidation catalyst to increase to a first regeneration temperature that is greater than or equal to 400 degrees Celsius and less than 550 degrees Celsius; cause the temperature of the oxidation catalyst to be maintained at the first regeneration temperature for a first time period; and after the first time period, cause the temperature of the oxidation catalyst to increase to a second regeneration temperature equal to or greater than 550 degrees Celsius.