Engine systems use a three-way catalyst followed by air injection and mixing to convert all hydrocarbons and carbon monoxide under various load conditions when exhaust gas temperature is above 500 degrees Celsius. A three-way catalytic converter is disposed in the exhaust system. A nozzle is configured to inject air into the exhaust system downstream from the three-way catalytic converter. A mixing plate with or without catalyst coatings is disposed in the exhaust system downstream from the nozzle. The mixing plate is bow shaped with a concave shaped side facing the nozzle to enhance carbon monoxide conversion. Optional two way catalytic converters are added downstream from the mixing plate to further reduce tailpipe hydrocarbon and carbon monoxide emissions.

An exhaust system of an internal combustion engine of a motor vehicle includes a particulate filter where particles are filterable out from the exhaust gas by the particulate filter. A selective catalytic reduction (SCR) catalytic converter through which the exhaust gas from the internal combustion engine is flowable for denitrifying the exhaust gas from the internal combustion engine is disposed downstream of the particulate filter. The exhaust gas of the internal combustion engine is heatable by a combustor at a point disposed upstream of the SCR catalytic converter and downstream of the particulate filter where the combustor provides an exhaust gas of the combustor. Particles are filterable out from the exhaust gas of the combustor by a filter element.

A method for controlling urea injection in an exhaust aftertreatment system includes injecting urea at a flow rate upstream of the first catalytic reduction device; measuring a level of nitrogen oxides downstream of the first catalytic reduction device and upstream of the second catalytic reduction device; controlling the flow rate of the urea injection until the measured level of nitrogen oxides fulfils a predetermined condition; if the measured level of nitrogen oxides is decreasing in response to reducing the flow rate of the urea injection, reducing the flow rate of the urea injection, and controlling a flow rate of urea injection using the second urea injector upstream of the second catalytic reduction device according to the measured level of nitrogen oxides downstream of the first catalytic reduction device and upstream of the second catalytic reduction device.

An exhaust treatment assembly for receiving exhaust gas from a motor vehicle includes a mix pipe, a sheath, and a heater. The mix pipe at least partially defines a passage adapted to receive the exhaust gas and a chemical reductant. The sheath includes a first end fluidly sealed to the mix pipe. At least a portion of the sheath is radially spaced apart from the mix pipe to at least partially define a gap. The heater is disposed in the gap. The heater is adapted to heat a reductant impingement surface.

A reaction device of a marine SCR system comprises a conveying unit (110), a reaction chamber (120), at least one catalyst module (130), and an air homogenization chamber (140), wherein, the conveying unit (110) includes an input pipeline (111) and an output pipeline (112) sleeved outside the input pipeline (111). One end of the reaction chamber (120) is connected to the conveying unit (110). The reaction chamber (120) comprises an inner cylinder (121) and an outer cylinder (122) sleeved outside the inner cylinder (121), the inner cylinder (121) is in communication with the input pipeline (111), and the outer cylinder (122) is in communication with the output pipeline (112). The catalyst module (130) is provided between the inner cylinder (121) and the outer cylinder (122). The air homogenization chamber (140) is connected to the other end of the reaction chamber (120) and is in communication with both the inner cylinder (121) and the outer cylinder (122). With the reaction device of the marine SCR system whereby the outer cylinder is sleeved outside the inner cylinder, flue gas from the inner cylinder is turned by the air homogenization chamber and then flows back into the outer cylinder. This can not only substantially reduce the size of the reaction device to improve the integration of the SCR system, but also allow the flue gas to turn in the air homogenization chamber and then flow back, so that the flue gas and a reducing agent can be fully mixed in the air homogenization chamber to improve the catalytic reaction efficiency.

A catalytic composition for treating a NOx-containing exhaust gas, wherein the composition comprises a copper-substituted small-pore zeolite comprising: i) Ce and/or La in a total amount of about 5 to about 400 g/ft.sup.3; and ii) Nd and/or Nb in a total amount of about 5 to about 400 g/ft.sup.3.

A diesel-electric locomotive includes a diesel emissions reduction unit, including an inlet configured to receive an exhaust stream of a high-speed diesel engine; means for trapping at least a portion of diesel particulate matter contained in the exhaust stream; an aqueous NH.sub.3 dosing system including a dosing controller in communication with an electronic locomotive controller and a nitrogen oxide (“NO.sub.x”) concentration sensor and an ammonia (“NH.sub.3”) concentration sensor, at least one oxidation catalyst panel arranged to isolate the NO.sub.x concentration sensor from NH.sub.3 in the exhaust stream; mixing elements located between the dosing system and the NO.sub.x and NH.sub.3 concentration sensors to mix metered aqueous NH.sub.3 in the exhaust stream; a selective catalyst reactor bed located between the mixing elements and the NO.sub.x and NH.sub.3 concentration sensors; and an exhaust heating system in communication with at least one of the dosing and electronic locomotive controllers.

A fluid filter, filtering medium composition, and associated process for removing contaminants from feed and exhaust fluids used in fuel cell electricity generation, laboratories, the semiconductor and other industries to improve performance and extend useful equipment lifetimes and to clean fluids of sulfur compound contaminants, as well as to remove noxious NOx contaminants from feed and exhaust gases.

A system and method for filtering exhaust gases of a vehicle is disclosed, that are based on an exhaust filter assembly includes an enclosure having an inlet coupled with an end of an exhaust pipe to allow exhaust gases of the vehicle into the enclosure, a filter element fitted with the enclosure to adsorb gaseous particles, moisture, and unburned fuel mist particles of the exhaust gases, sensors to sense gaseous particles adsorbed on the filter element, and generate first signals based on the sensed gaseous particles; a control unit; and a communication unit. The control unit includes processors to: receive the generated first signals, and generate second signals based on the received first signals. The communication is configured to transmit the second signals to computing devices of users to notify the users. Thermoelectric generator is adapted to convert heat energy of the exhaust gases into electric power.

A diesel-emissions reduction unit having an inlet adapted to receive an exhaust stream of the diesel engine; a diesel oxidation trap catalyst located adjacent the inlet; a dosing controller and an injection lance arranged to meter aqueous NH.sub.3 into the exhaust stream; a NOx concentration sensor and a NH.sub.3 concentration sensor with at least one oxidation catalyst panel arranged to isolate the NOx concentration sensor from NH.sub.3 in the exhaust stream; and an exhaust heater arranged to heat the exhaust stream of the diesel engine toward the inlet of the diesel emissions reduction unit.