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.

The present invention relates to a method for producing automobile exhaust gas catalytic converters, to the catalytic converters as such and to the use thereof. In particular, the method comprises a step which results in a smaller particle size of the catalytically active material used.

Various embodiments include methods for determining the efficiency of an SCR catalytic converter in a system including a nitrogen oxide sensor, and a metering device for a reducing agent arranged in an exhaust-gas duct, and an exhaust recirculation line with a recirculation valve disposed downstream of the SCR catalytic converter and feeding an intake region of the engine. The methods comprise: setting or identifying a quasi-steady-state operating state and an associated recirculation rate; adding a first quantity of reducing agent using the metering device; measuring a resulting first nitrogen oxide value using the sensor; adding a further predefined quantity, different from the first quantity; measuring the resulting nitrogen oxide values using the sensor; and determining the efficiency of the SCR catalytic converter based at least in part on the associated exhaust-gas recirculation rate and the measured nitrogen oxide values.

An aftertreatment system includes a first exhaust gas path, a second exhaust gas path, and a selector valve configured to divert exhaust gas between the first exhaust gas path and the second exhaust gas path based on a temperature of the exhaust gas. The aftertreatment system also includes a controller programmed to control the selector valve such that the selector valve diverts at least a portion of the exhaust gas to the first exhaust gas path when the temperature of the exhaust gas is equal to or less than a predetermined temperature threshold and the selector valve diverts the exhaust gas to the second exhaust gas path when the temperature of the exhaust gas is greater than the predetermined temperature threshold. The first exhaust gas path includes a heater configured to heat the exhaust gas received in the first exhaust gas path.

The invention relates to a method for improving the efficiency of an SCR system of an exhaust gas aftertreatment system (5) of an internal combustion engine (1), and to an internal combustion engine (1), wherein an operating medium is metered in upstream of the SCR catalytic converter (2) of the SCR system in a normal operating mode, wherein the operating medium comprises a reducing agent or can be converted into a reducing agent, wherein the reducing agent is stored at least temporarily in an SCR catalytic converter (2) of the SCR system, wherein the method comprises the following steps: operating of the internal combustion engine (1) in the normal operating mode, defining of a determined control value (6) by way of determining of the mass of an exhaust gas component which is measured overall at a point in the course of the exhaust gas aftertreatment system (5) during a first measurement window, determining of a calculated control value (7) by way of calculating of the mass of the exhaust gas component which occurs overall at the point in the course of the exhaust gas aftertreatment system (5) during the first measurement window, determining of the deviation (8) between the determined control value and the calculated control value, checking whether the determined deviation lies within a predefined deviation range, adapting of the metering quantity of the operating medium if the determined deviation lies outside the deviation range.

To provide an exhaust gas purification catalyst that is less likely to cause an increase in pressure loss, even a large amount of zeolite-based SCR catalyst is used to improve NOx purification capability. The exhaust gas purification catalyst includes a DPF provided with zeolite having a primary particle size equal to or less than 0.5 μm. In addition, it is preferable that 50% particle size of the zeolite measured by dynamic light scattering is equal to or less than 2.0 μm, and further, it is preferable that the 90% particle size of the zeolite is equal to or less than 2.5 μm.

JMZ-1S, a silicoaluminophosphate molecular sieve having a CHA structure and containing a trimethyl(cyclohexylmethyl)ammonium cation cation is described. A calcined product, JMZ-1SC, formed from JMZ-1S is also described. Methods of preparing JMZ-1S, JMZ-1SC and metal containing calcined counterparts of JMZ-1SC are described along with methods of using JMZ-1SC and metal containing calcined counterparts of JMZ-1SC in treating exhaust gases and in converting methanol to olefines.

A water intrusion cover for a sensor probe in an exhaust system is provided. The water intrusion cover includes a main body portion having a substantially cylindrical shape, an inlet opening, and an outlet opening. The inlet opening and outlet opening are formed in a sidewall of the main body portion and are fluidly coupled to form a continuous flow path defined by a surface that, in a cross-section perpendicular to an axis of the main body portion, curves from the inlet opening to the outlet opening. The water intrusion cover further includes a shoulder portion having a substantially cylindrical shape. The main body portion and the shoulder portion collectively define a central passage for the sensor probe.

A dosing composition and method for treatment of reductant urea solutions utilizing organometallic catalyst precursors in combination with one or more surfactants to promote decomposition of relatively high molecular weight deposits which deposits may otherwise reduce selective catalytic reduction efficiency.

An improved SCRoF (selective catalytic reduction on filter) device for treating exhaust from an internal combustion engine. The filter has numerous entry and exit channels. Exhaust enters the entry channels and flows through side walls into the exit channels. Relative to the exhaust flow path, these side walls are coated on the downstream side with a ceria-based catalyst and on the upstream side with a Cu-zeolite catalyst. This allows the filter to optimally achieve both particulate matter oxidation and NOx reduction, respectively.