The invention relates to a method for the operation of an exhaust gas aftertreatment system in an exhaust tract of an internal combustion engine. The exhaust gas aftertreatment system includes an SCR particle filter, a first reducing agent feed device for introducing the reducing agent into the exhaust tract upstream of the SCR particle filter, continuous regeneration of the SCR particle filter being possible using nitrogen dioxide as oxidizing agent, an SCR catalytic converter element arranged downstream of the SCR particle filter, and a second reducing agent feed device for introducing the reducing agent into the exhaust tract downstream of the SCR particle filter and upstream of the SCR catalytic converter element. A control unit regulates a quantity of reducing agent introduced into the exhaust tract by the first reducing agent feed device and/or by the second reducing agent feed device as a function of the temperature (T.sub.SCR-PF) of the SCR particle filter.

An engine system includes a compression ignition diesel engine connected with an aftertreatment system. A source of diesel fuel, which may have a high sulfur content, is fluidly connected to the engine. The aftertreatment system includes a particle trap fluidly positioned between the engine and the tailpipe, and an SCR catalyst fluidly positioned on the particle trap or between the particle trap and the engine. The SCR catalyst is a sulfur tolerant SCR catalyst. A non-thermal particle trap regeneration system includes a valve fluidly positioned between a particulate volume and an inlet to the particle trap. A reductant system has a doser positioned, possibly in the exhaust manifold, to deliver a reductant into the aftertreatment system upstream from the SCR catalyst.

The present disclosure is directed to a method for treating a gaseous exhaust stream containing nitrogen oxides (NO.sub.x) from a diesel or lean-burn gasoline engine following a cold-start of the engine The method involves contact of the gaseous exhaust stream with at least a low temperature NO.sub.x adsorber (LT-NA) component. The LT-NA component includes a rare earth metal component, a platinum group metal (PGM) component, and a dopant. The present disclosure is also directed to a method of modulating a NO.sub.x adsorption/desorption profile of an LT-NA composition, a NO.sub.x desorption temperature range of an LT-NA composition, or both.

The present disclosure relates to a substrate containing passive NO.sub.x adsorption (PNA) materials for treatment of gases, and washcoats for use in preparing such a substrate. Also provided are methods of preparation of the PNA materials, as well as methods of preparation of the substrate containing the PNA materials. More specifically, the present disclosure relates to a coated substrate containing PNA materials for PNA systems, useful in the treatment of exhaust gases. Also disclosed are exhaust treatment systems, and vehicles, such as diesel or gasoline vehicles, particularly light-duty diesel or gasoline vehicles, using catalytic converters and exhaust treatment systems using the coated substrates.

An air dryer includes a supporting base, a drying agent container, and an outer cover. The supporting base includes an inlet for receiving compressed air to be subject to a drying process and an outlet for delivering the processed compressed air that has undergone the drying process. The drying agent container is a container supported on the supporting base, contains a drying agent in the interior, and enables the drying process to be performed by passing the compressed air from the inlet through the drying agent. The outer cover surrounds the outer side of the drying agent container on the supporting base and defines a chamber for storing the compressed air between itself and the drying agent container. The supporting base includes first and second mounting surfaces, which are oriented in different directions, and a plurality of inlets, which are oriented in different directions and receive the compressed air.

Methods and systems are provided for reducing engine cold-start emissions. An exhaust system having a passive NOx adsorber (PNA) may store NOx during an engine cold-start until conditions are optimal for release of the stored NOx to a downstream SCR catalyst. Based on PNA conditions, including a NOx load and a PNA bed temperature, adjustments to EGR rate and/or injection timing may be made to achieve a catalytically favorable ratio of NOx species upstream of the SCR catalyst, after the SCR catalyst has reached its light-off temperature.

A method for reducing the level of occluded alkali metal cations from an MSE-framework type molecular sieve comprises either (a) contacting the molecular sieve with a solution containing ammonium ions at a temperature of at least about 50 C. to ammonium-exchange at least part of the occluded potassium ions or (b) contacting the molecular sieve with steam at a temperature of at least about 300 C. and then subjecting the steamed molecular sieve to ammonium exchange.

An oxidation catalyst for treating an exhaust gas produced by a compression ignition engine comprising: a substrate; a catalytic material disposed on the substrate, wherein the catalytic material comprises platinum (Pt); and a region comprising a capture material, wherein the capture material comprises a Pt-alloying metal disposed or supported on a refractory oxide, wherein the refractory oxide comprises at least 65% by weight of zirconia, wherein the region is arranged to contact the exhaust gas after the exhaust gas has contacted and/or passed through the catalytic material.

An exhaust purification system includes an exhaust after-treatment apparatus which is provided on an exhaust passage of an internal combustion engine and which includes catalysts for purifying exhaust gas, a catalyst temperature retention control module for executing a catalyst temperature retention control in which an intake air flow is reduced to thereby suppress a reduction in the temperature of the catalysts when the internal combustion engine is in a motoring state where fuel injection into the internal combustion engine is stopped, and a prohibition module for prohibiting the execution of the catalyst temperature retention control in a case where an activation of an exhaust brake system is detected while the internal combustion engine is in the motoring state.

An evaporative emission control canister system comprises an initial adsorbent volume having an effective incremental adsorption capacity at 25 C. of greater than 35 grams n-butane/L between vapor concentration of 5 vol % and 50 vol % n-butane, and at least one subsequent adsorbent volume having an effective incremental adsorption capacity at 25 C. of less than 35 grams n-butane/L between vapor concentration of 5 vol % and 50 vol % n-butane, an effective butane working capacity (BWC) of less than 3 g/dL, and a g-total BWC of between 2 grams and 6 grams. The evaporative emission control canister system has a two-day diurnal breathing loss (DBL) emissions of no more than 20 mg at no more than 210 liters of purge applied after the 40 g/hr butane loading step.