422 results about "Diesel exhaust" patented technology

A filter, system and method is provided for filtering nanoparticles in a hot gas, namely particles <about 1 micron in a gas >about 200° C. and further particularly >about 450° C. including diesel exhaust. The filter includes filter media material composed of fibrous filter media having a plurality of fibers and granular filter media having a plurality of granules extending from the surfaces of the fibers. The filter is characterized by a permeability >about 3×10−12 m2 and an inertial resistance coefficient <about 1×106 m−1. The filter captures particles in the Most Penetrating Region (MPR). A filter system includes a nanoparticle filter in series with a diesel exhaust treatment element.

The invention is directed at a mullite-aluminum titanate porous diesel particulate filter constituting a porous ceramic body containing, expressed in terms of weight percent of the total body, of 60-90%, preferably 70-80%, most preferably 70% iron-aluminum titanate solid solution having a stoichiometry of Al2(1−x)Fe2xTiO5, where x is 0-0.1, and 10-40%, preferably 20-30%, most preferably 30% mullite (3Al2O3.2SiO2), and consists essentially, expressed in terms of weigh percent on the oxide basis, of 3 to 15% SiO2, 55 to 65% Al2O3, 22 to 40% TiO2, and 0 to 10% Fe2O3, and being useful for filtration of diesel exhaust. The inventive diesel particulate filter exhibits high interconnected open porosity and large median pore size, in combination with high permeability when fired to a temperature of between 1650° to 1700° C., along with high thermal shock resistance and good filtration capability.

An aluminum titanate-based ceramic body having a composition a formula comprising a(Al2O3.TiO2)+b(CaO.Al2O3.2SiO2)+c(SrO.Al2O3.2SiO2)+d(BaO.Al2O3.2SiO2)+e(3Al2O3.2SiO2)+f(Al2O3)+g (SiO2)+h(Fe2O3.TiO2)+i(MgO.2TiO2), wherein a, b, c, d, e, f, g, h, and i are weight fractions of each component such that (a+b+c+d+e+f+g+h+i)=1, wherein 0.5<a≦0.95; 0≦b≦0.5; 0≦c≦0.5; 0≦d≦0.5; 0<e≦0.5; 0≦f≦0.5; 0≦g≦0.1; 0≦h≦0.3; 0≦i≦0.3; b+d>0.01. A method of forming the ceramic body is provided. The ceramic body is useful in automotive emissions control systems, such as diesel exhaust filtration.

The invention is directed at a mullite-aluminum titanate porous diesel particulate filter constituting a porous ceramic body containing, expressed in terms of weight percent of the total body, of 60-90%, preferably 70-80%, most preferably 70% iron-aluminum titanate solid solution having a stoichiometry of Al2(1-x)Fe2xTiO5, where x is 0-0.1, and 10-40%, preferably 20-30%, most preferably 30% mullite (3Al2O3.2SiO2), and consists essentially, expressed in terms of weigh percent on the oxide basis, of 3 to 15% SiO2, 55 to 65% Al2O3, 22 to 40% TiO2, and 0 to 10% Fe2O3, and being useful for filtration of diesel exhaust. The inventive diesel particulate filter exhibits high interconnected open porosity and large median pore size, in combination with high permeability when fired to a temperature of between 1650° to 1700° C., along with high thermal shock resistance and good filtration capability.

The invention provides low temperature NO2 trap compositions useful for adsorbing NO2 from a gas stream at lower temperatures, and releasing the NO2 at higher temperatures. The low temperature trap compositions are useful for incorporation into a diesel exhaust system equipped with a soot filter. The NO2 from the diesel exhaust can be stored when the exhaust temperature is cool, e.g., during startup and at times of low load, and released when the exhaust is at higher temperatures. The released NO2 serves as an effective oxidant for the combustion of soot deposited on the soot filter. These temperatures are significantly lower than those required for the combustion of soot using O2 as an oxidant. The methods of the invention thereby provide a method for regenerating the soot filter within operating temperature ranges typical of diesel engine exhaust systems.

An aluminum titanate-based ceramic article having a composition comprising u (Al2O3—TiO2)+v (R)+w (3Al2O3—2SiO2)+x (Al2O3)+y (SiO2)+z (1.1SrO-1.5Al2O3-13.6SiO2—TiO2)+a (Fe2O3—TiO2)+b (MgO-2TiO2), where, R is SrO—Al2O3-2SiO2 or 11.2SrO-10.9Al2O3-24.1SiO2—TiO2, where u, v, w, x, y, z, a and b are weight fractions of each component such that (u+v+w+x+y+z+a+b=1), and 0.5<u≦0.95, 0.01<v≦0.5, 0.01<w≦0.5, 0≦x≦0.5, 0≦y≦0.1, 0≦z≦0.5, 0<a≦0.3, and 0≦b≦0.3. A method of forming the ceramic article is provided. The ceramic article is useful in automotive emissions control systems, such as diesel exhaust filtration.

Disclosed are ceramic articles, which in one aspect are composed predominately of a cordierite having a composition close to that of Mg2Al4Si5O18. The ceramic articles possess a microstructure characterized by a unique combination of relatively high porosity and relatively narrow pore size distribution, both as measured by mercury porosimetry, that render the ceramic structure useful for ceramic filter applications requiring high thermal durability and high filtration efficiency coupled with low pressure drop along the length of the filter. Such ceramic bodies are particularly well suited for filtration applications, such as diesel exhaust filters or DPFs. Also disclosed are methods for the manufacture of the ceramic articles described herein.

A coated diesel exhaust filter is provided that applies a relatively low pressure drop across the exhaust system despite the buildup of soot deposits. The filter includes a porous ceramic structure having an inlet end, an outlet end, and a plurality of gas inlet and gas outlet channels disposed between the inlet and outlet ends, the channels being separated by porous ceramic walls. A catalyst is distributed at least partly within the porous ceramic walls of the structure, and is distributed at a higher concentration within portions of the ceramic walls adjacent to the outlet surfaces than within portions of the ceramic walls adjacent the inlet surfaces. Both the inlet and outlet surfaces are substantially free of the catalyst in order to maintain a gas-conducting porosity in these surfaces. The resulting filter effectively treats nitrogen oxides, carbon monoxide and unburned hydrocarbons present in the exhaust gas stream while advantageously imposing a relatively low pressure drop across the exhaust system even when soot deposits accumulate on the inlet surfaces of the ceramic walls.

A diesel exhaust treatment system and method of oxidizing NO to NO.sub.2 at low temperatures are provided. The system utilizes a platinum catalyst on a zirconia-stabilized silica support which oxidizes NO in the exhaust gas to NO.sub.2 and uses the NO.sub.2 in an amount sufficient to oxidize particulate trapped on a particulate filter. The catalyst is preferably pre-treated at a temperature of between about 500 to 650.degree. C. in a NO-oxygen-nitrogen mixture to increase conversion at low temperatures. The catalyst preferably includes an additional oxide component selected from the group consisting of TiO.sub.2, P.sub.2 O.sub.5, WO.sub.3, B.sub.2 O.sub.3, and Al.sub.2 O.sub.3. or a heteropolyacid component to further increase activity at low temperatures or to decrease platinum loading at the same level of performance.

An oxidation catalyst for the treatment of exhaust gas emissions, such as the oxidation of unburned hydrocarbons (HC), and carbon monoxide (CO) and the reduction of nitrogen oxides (NOx) from a diesel engine and methods of exhaust gas treatment are disclosed. More particularly, a washcoat composition is disclosed comprising at least two washcoat layers, a first washcoat comprising palladium supported on ceria-zirconia and ceria-zirconia-alumina and a second washcoat containing one or more of platinum and palladium and one or more hydrocarbon storage components. An undercoat may also be included in the catalyst. Also disclosed are method of exhaust gas treatment and diesel exhaust gas treatment systems that include the oxidation catalyst and a downstream soot filter.

A diesel exhaust treatment system and method of oxidizing NO to NO2 at low temperatures are provided. The system utilizes a platinum catalyst on a zirconia-stabilized silica support which oxidizes NO in the exhaust gas to NO2 and uses the NO2 in an amount sufficient to oxidize particulate trapped on a particulate filter. The catalyst is preferably pre-treated at a temperature of between about 500 to 650° C. in a NO-oxygen-nitrogen mixture to increase conversion at low temperatures. The catalyst preferably includes an additional oxide component selected from the group consisting of TiO2, P2O5, WO3, B2O3, and Al2O3. or a heteropolyacid component to further increase activity at low temperatures or to decrease platinum loading at the same level of performance.

Disclosed are ceramic honeycomb articles, which are composed predominately of a crystalline phase cordierite composition. The ceramic honeycomb articles possess a microstructure characterized by a unique combination of relatively high total porosity of less than 54%, and relatively narrow pore size distribution having a d10 pore diameter of not less than 8 μm, a d90 pore diameter of not greater than 35 μm, and a value of df=(d50−d10) / d50 of less than 0.50. The articles exhibit high thermal durability and high filtration efficiency coupled with low pressure drop across the filter. Such ceramic articles are particularly well suited for filtration applications, such as diesel exhaust filters or DPFs. Also disclosed are methods for manufacturing the ceramic articles of the present invention.

A system for aftertreatment of diesel engine exhaust on a vehicle which is equipped for dynamic braking, using the electrical power generated by the dynamic braking to energize a resistor bank which incinerates particulate matter which has been collected in a particulate matter filter, thereby regenerating the filter.

The invention discloses an SCP urea injection system for the post treatment of diesel engine emissions, which belongs to internal combustion engine waste gas purification systems, comprises a urea solution box, a conveying pump, a filter, a urea nozzle, a pressure sensor and a temperature sensor, and is characterized in that the urea injection system comprises an energy accumulator, a large-capacity injection accommodating cavity and a device for heating urea solution by diesel exhaust, wherein the energy accumulator is connected with a main pipeline of the system in parallel and is used for stabilizing the pressure of the main pipeline; the large-capacity injection accommodating cavity is directly connected with the urea nozzle; and the device for heating the urea solution by the diesel exhaust comprises a waste gas inlet pipe, a temperature control valve, a waste gas outlet pipe and the like, wherein the urea nozzle adopts a pintle type nozzle which can prevent the urea from being crystallized at a low temperature to block an injection orifice. The system can realize precise and reliable injection metering of the urea solution.

This invention provides a method of reducing nitrogen oxides in an oxygen containing exhaust stream using ethanol as a reductant for plasma-assisted selective catalytic reduction. The exhaust gas, generated from a diesel engine or other lean-burn power source, comprises nitrogen oxides, especially NO. Ozone generated from a plasma reactor is injected into the exhaust stream to convert NO to NO2 and the plasma injection is followed by the addition of ethanol. The NO2 is then reduced by contacting the exhaust stream with a dual-bed catalytic reactor comprising BaY (or NaY) and CuY zeolite catalysts in the presence of ethanol as the reductant. The plasma power density and the molar ratio of ethanol to NOx fed to the catalytic reactor are controlled as a function of the catalyst temperature for the best performance of the plasma-catalyst system. An average conversion of NOx to N2 of at least 90% is achieved over the temperature range of 200–400° C.

A diesel exhaust aftertreatment device regeneration system includes an exhaust conduit adapted to conduct exhaust gas to an exhaust gas aftertreatment device. The system further includes a low pressure bottom feed fuel injector having an inlet portion fully received within a chamber of an adaptor housing having a lower portion attached to the exhaust conduit. The housing is provided with fuel flow openings to allow low pressure fuel to circulate around and cool the fuel injector inlet portion within the chamber. Fuel injected into the exhaust conduit is preferably targeted toward a vaporization member, within the exhaust conduit, operative to absorb heat from the exhaust gas and vaporize fuel deposited thereon. A plurality of inwardly extending mixing baffles within the exhaust conduit intermediate the vaporization member and the aftertreatment device extend the mixing path to improve fuel vaporization for assisting regeneration of the device.

A exhaust system and method for venting exhaust from an engine, such as a diesel engine, through an exhaust line coupled to the engine includes a first particulate filter disposed in the exhaust line and “close-coupled” with the engine, and a second particulate filter spaced a distance (d) from the first filter. The first particulate filter is “close-coupled” so that it operates in a passive regeneration mode to a greater extent than the second particulate filter. The first particulate filter may be a partial wall-flow filter including some plugged and some open channels. Some of the plugged channels may be plugged adjacent to an inlet end and others may be plugged adjacent to an outlet end. A partial wall-flow filter is also described having some unplugged flow-through channels and some plugged channels wherein some plugged channels are located adjacent to the inlet end and some are located adjacent to the outlet end.

A dosing valve assembly is disclosed for administering a reducing agent into an exhaust stream within an exhaust manifold of an internal combustion engine. The dosing valve assembly comprises a control valve coupled to a source of the reducing agent, a reducing agent delivery valve constructed and arranged for coupling to the exhaust manifold to enable a specified quantity of reducing agent to be administered into the exhaust stream, and an elongated conduit disposed between the control valve and reducing agent delivery valve for fluidly communicating reducing agent from the control valve to the reducing agent delivery valve. The disclosed arrangement enables the reducing agent delivery valve to be coupled to the exhaust manifold and the control valve to be displaced from the reducing agent delivery valve and away from the high temperature environment associated with the exhaust manifold.

Systems and methods to determine when regeneration of a diesel particulate filter (DPF) are presented. Such determination is made by indirectly determining soot accumulation in the DPF by monitoring soot accumulation on a regeneration burner spark plug based on the correlation between spark plug fouling and DPF soot loading. An ion current sensing circuit is used during periods of no flame to determine soot loading on the spark plug. When soot loading on the spark plug approaches an amount that could cause fouling of the spark plug, the ignition controller initiates a hot spark to burn the soot off the spark plug. The number of such cleaning events is tracked and used to determine when the DPF soot loading is at a level that regeneration should be initiated. Temperature rise across the DPF is monitored and used to adjust the number spark plug cleaning events needed before initiating regeneration.

The invention relates to a cerium-zirconium-tungsten composite oxide catalyst used for carrying out selective catalytic reduction on nitric oxide by ammonia, as well as a preparation method and usage thereof. The catalyst is a composite metal oxide formed by three types of metal including cerium, zirconium and tungsten. The catalyst adopts non-toxic and harmless raw materials; the cerium-zirconium-tungsten composite oxide catalyst which can adapt to high space velocity reaction condition and has the characteristics of being excellent in catalytic activity, high in N2 generation selectivity, wide in operating temperature window and the like can be prepared by using a simple and practicable method; and the cerium-zirconium-tungsten composite oxide catalyst is suitable for a nitric oxide catalytic purification device used for a moving source represented by diesel exhaust and a fixed source represented by flue gas of a coal-fired power plant.

A system is provided for removing particulate matter from a diesel particulate filter. The diesel particulate filter includes at least one diesel particulate filter unit to filter particulate matter from diesel engine exhaust gas received from a diesel engine. The system includes a sensor positioned adjacent to at least one diesel particulate filter unit, where the sensor is configured to determine the extent of particulate matter trapped within the diesel particulate filter unit. The system further includes an engine controller coupled to the sensor and the diesel engine, where the sensor is configured to output a first alert signal to the engine controller upon determining that the trapped particulate matter exceeds a predetermined threshold. The engine controller is configured to increase the temperature of the diesel exhaust gas entering the diesel particulate filter upon receiving the first alert signal.

An exhaust cleanup filter which, even if the exhaust temperature is low as during vehicular driving under low load, can trap PM efficiently to prevent clogging by PM buildup and which also is effective in purifying the exhaust from a diesel engine that does not use any burner or heater to remove PM. The cleanup filter is for purifying the exhaust from diesel engines and comprises particulate ceramic porous bodies that have a three-dimensional network structure, as well as artificial pores and communication channels in the interior, with some of the pores being partially exposed on the surfaces of the porous bodies.

This invention relates to an aluminum titanate body having a narrow pore size distribution as characterized by the relation (d50−d10) / d50 being less than 0.50 corresponding to a high degree of interconnected porosity. The body also preferably exhibits a low coefficient of thermal expansion of less than 15×10−7 C−1, high porosity of at least 38% by volume, and at least 0.10% by weight metal oxide, the metal being either yttrium, calcium, bismuth, a lanthanide metal or combinations of thereof. MOR is preferably at least 450 psi. Median pore diameter is preferably at least 8 microns. The inventive ceramic body is particularly useful as a wall-flow filter for a diesel exhaust. A method of fabrication is provided where the sintering temperature is preferably between 1375°-1550° C.

A diesel particulate filter construction, for filtering particulate from a flow of exhaust, includes a first layer of electrically resistive metal filter material in line with the flow of exhaust with particulate therein and a second layer of electrically resistive filter material which is also in line with the flow of exhaust with particulate therein. The layers are pleated cylinders concentrically positioned relative to one another. Current from a power supply is routed through the first layer and the second layer, which are electrically connected in series to one another. The layers are positioned so that exhaust flows through both the layers. Sufficient heat is generated by the flow of current through the layers to generate heat to, in turn, burn off entrapped particulate. The layers may be made of made of different materials of different fiber sizes or coated with different catalysts to generate different amounts of heat from one another to improve the filtration characteristics of the particulate filter construction.

A burner (18) is provided for use in a diesel exhaust gas treatment system (10) to treat an exhaust flow (12) from a diesel combustion process (14). The burner (18) includes an inner housing (34) defining a combustion flow path (40) to direct a first portion of the exhaust flow (12) through an ignition zone (42) wherein fuel is ignited, an outer housing (32) surrounding the inner housing (34) to define an annular bypass flow path (44) between the inner and outer housings (34, 32) to bypass a second portion of the exhaust flow (12) around the ignition zone (42), and a mixer (48) including a plurality of flow restrictor fingers (50) that extend across the bypass flow path (44) to restrict an available flow area of the bypass flow path (44), and a plurality of mixer fingers (52) having portions that extend inwardly from a location downstream from the inner housing (34).

An aluminum titanate-based ceramic body having a composition a formula comprising a(Al2O3.TiO2)+b(CaO.Al2O3.2SiO2)+c(SrO.Al2O3.2SiO2)+d(BaO.Al2O3.2SiO2)+e(3Al2O3.2SiO2)+f(Al2O3)+g (SiO2)+h(Fe2O3.TiO2)+i(MgO.2TiO2), wherein a, b, c, d, e, f, g, h, and i are weight fractions of each component such that (a+b+c+d+e+f+g+h+i)=1, wherein 0.5<a≦0.95; 0≦b≦0.5; 0≦c≦0.5; 0≦d≦0.5; 0<e≦0.5; 0≦f≦0.5; 0≦g≦0.1; 0≦h≦0.3; 0≦i≦0.3; b+d>0.01. A method of forming the ceramic body is provided. The ceramic body is useful in automotive emissions control systems, such as diesel exhaust filtration.

A system is provided for removing particulate matter from a diesel particulate filter. The system includes an engine controller coupled to the diesel engine, and to a locomotive controller. The locomotive controller includes an algorithm to create a trip plan to optimize the performance of the locomotive along a route in accordance with a power setting of the diesel engine at each location along the route. Each sensor is configured to output a first alert signal to the engine controller once the trapped particulate matter exceeds a predetermined threshold. Upon receiving the first alert signal, the engine controller communicates with the locomotive controller to determine a time region or distance region within the trip plan when the power setting exceeds a power threshold. The engine controller increases the temperature of the diesel exhaust gas entering the diesel particulate filter during the time region or distance region.