An urea injection control system for an internal combustion engine, specifically adapted to apply a scheme for decreasing a NOx level downstream of a selective catalytic reduction catalyst of an ICE related exhaust gas aftertreatment system. The present disclosure also relates to a corresponding computer implemented method and a computer program product.

An apparatus and method for treating a semiconductor process gas comprises a gas inlet allowing a treatment target gas (or gas to be treated) to flow therethrough; a catalytic reaction portion including a catalyst and configured to allow the treatment target gas to be brought into contact with the catalyst; a space velocity controller between the gas inlet and the catalytic reaction portion, the space velocity controller extending from the gas inlet in a diagonal direction in relation to the gas inlet; a differential pressure buffer portion between the space velocity controller and the catalytic reaction portion and including a filter; and a gas outlet configured to externally discharge a product formed as the treatment target gas comes into contact with the catalyst.

An aftertreatment system comprises a SCR system, a first filter, and a second filter disposed downstream of the first filter and a bypass conduit providing a flow path bypassing the second filter. A valve is operatively coupled to the bypass conduit and is moveable between a closed position in which the exhaust gas flows through the second filter, and an open position in which at least a portion of the exhaust gas flows through the bypass conduit. A controller is operatively coupled to the valve configured to adjust the valve based on a first filtration efficiency of the first filter to cause the exhaust gas expelled into the environment from the aftertreatment to have a particulate matter count meeting particulate matter emission standards.

A mixer apparatus for an exhaust gas aftertreatment system of a motor vehicle. The apparatus includes a housing having enveloping, first end, and second end walls. An injection opening for an exhaust gas aftertreatment agent is in the enveloping wall. An inlet opening is in the first end wall. The injection opening is configured for mounting a metering module. A rectilinear metering axis, which extends through the metering module and corresponds to an injection direction of exhaust gas aftertreatment agent injected into the housing, tangentially contacts, at a contact point, a theoretical cylinder, disposed in the housing, having a variable radius and a cylinder axis that is congruent with a central axis of the housing. A region of the metering axis extending from the injection opening to the contact point is located, with respect to inflowing exhaust gas, in the shelter of an opening-free region of the first end wall.

Disclosed is a method of preparing a high-performance zeolite catalyst for reducing nitrogen oxide emissions, and more particularly a technique for preparing a zeolite catalyst, suitable for use in effectively removing nitrogen oxide (NOx), among exhaust gases emitted from vehicle internal combustion engines through selective catalytic reduction (SCR), thereby exhibiting high efficiency, high chemical stability and high thermal durability upon SCR using the prepared catalyst.

A porous ceramic honeycomb body (10) including intersecting walls that form channels (22) extending axially from a first end face to a second end face and layered plugs (62) comprised of a first layer (64) disposed on channel walls and a second layer (66) disposed inward toward an axial center of each respective channel on the first layer. The plugs seal at least one of a first portion of the channels at the first end face and a second portion of channels at the second end face of the porous ceramic honeycomb body.

The present disclosure relates to processes for formation of a molecular sieve, particularly a metal-promoted molecular sieve, and more particularly an Iron(III) exchanged zeolite. Preferably, the zeolite is of the chabazite form or similar structure. The processes can include combining a zeolite with Iron(III) cations in an aqueous medium. The process can be carried out at a pH of less than about 7, and a buffering material can be used with the aqueous medium. The processes beneficially result in Iron exchange that can approach 100% along with removal of cations (such as sodium, NH.sub.4, and H) from the zeolite. An Iron(III)-exchanged zeolite prepared according to the disclosed processes can include about 2,000 ppm or less of cation and about 1% by weight or greater of Iron(III). The disclosure also provides catalysts (e.g., SCR catalysts) and exhaust treatment systems including the Iron(III)-exchanged zeolite.

The present invention relates to an aqueous suspension comprising water, a source of one or more of a vanadium oxide and a tungsten oxide, and particles of an oxidic support; wherein the particles of the aqueous suspension exhibit a polymodal particle size distribution characterized by a particle size distribution curve comprising a first peak with a maximum M(I) in the range of from 0.5 to 15 micrometers and a second peak with a maximum M(II) in the range of from 1 to 40 micrometers, wherein (M(I)/μm):(M(II)/μm)<1:1.

A system (2) comprising (i) a vehicular compression ignition engine (1) comprising one or more engine cylinders and one or more electronically-controlled fuel injectors therefor; (ii) an exhaust line (3) for the engine comprising: a first emissions control device (5) comprising a first honeycomb substrate, which comprises a hydrocarbon adsorbent component; and a second emissions control device (7) comprising an electrically heatable element (7a) and a catalysed second honeycomb substrate (7b), which comprises a rhodium-free platinum group metal (PGM) comprising platinum, wherein the electrically heatable element (7a) is disposed upstream from the catalysed second honeycomb substrate (7b) and wherein both the electrically heatable element (7a) and the catalysed second honeycomb substrate (7b) are disposed downstream from the first honeycomb substrate; a third emissions control device (22), which is a third honeycomb substrate comprising an ammonia-selective catalytic reduction catalyst disposed downstream from the second emissions control device (7); and one or more temperature sensors located: upstream of the electrically heatable element and/or upstream of the first honeycomb substrate; and between the electrically heatable element (7a) and the catalysed second honeycomb substrate (7b); and (iii) an engine control unit (20) comprising a central processing unit pre-programmed, when in use, to control both a heating activation state of the electrically heatable element (7a); an injection timing strategy of the one or more electronically-controlled fuel injector to increase the temperature of at least the first emissions control device following key-on/cold-starting a vehicle comprising the system, wherein the one or more temperature sensors are electrically connected to the engine control unit for feedback control in the system.

A start-up method for heating a selective catalytic reduction (SCR) module in a hybrid propulsion system of a vehicle. An internal combustion engine is in fluid communication with an exhaust aftertreatment system having an exhaust. An SCR module is disposed in the exhaust passage downstream of the engine and an electric motor. The method includes operating the engine in a start-up mode with a torque restriction on the engine, allowing the SCR module to convert NOx emission; supplying a surplus amount of a reducing agent to the exhaust gas at a position between the engine and the SCR module, the surplus amount of the reducing agent being larger than a required amount of reducing agent for converting NOx emission from the engine; heating said SCR module to a working temperature; and terminating the start-up mode.