1459 results about "Diesel particulate filter" patented technology

A system for effective NOx and particulate matter control in a diesel or other lean burn internal combustion engine is presented. The system includes a urea-based SCR catalyst having an oxidation catalyst coupled upstream of it and a particulate filter coupled downstream of the SCR catalyst. This system configuration results in improved NOx conversion due to fast SCR catalyst warm-up and higher operating temperatures. Additionally, placing the particulate filter last in this system configuration reduces tailpipe ammonia emissions as well as prevents any thermal damage to the SCR catalyst due to the particulate filter regeneration.

A diesel engine exhaust treatment system and method is provided which utilizes a diesel particulate filter positioned in the exhaust gas stream of a vehicle which includes an SCR catalyst, an ammonia oxidation catalyst, and / or a diesel oxidation catalyst. The system is capable of performing multiple functions including converting NOx to N2, converting HC and CO to H2O and CO2, trapping particulates, and minimizing ammonia emissions. The system is more compact and efficient than prior systems utilizing separate catalyst units, and minimizes backpressure while maximizing catalyst performance.

One concept of the inventors relates to a system and method in which a particulate filter comprises at least about 40% by weight of an NOx adsorbant. The filter can be used as both an NOx trap and a particulate filter. By constructing the filter elements using a substantial amount of NOx adsorbant, a large volume of NOx adsorbant can be incorporated into the particulate filter, which substantially reduces the volume and expense of an exhaust system that includes both a catalytic diesel particulate filter and an NOx trap having a large quantity of NOx adsorbant. In a preferred embodiment, the filter also oxidizes NO to NO2. In another preferred embodiment, an SCR catalyst is position downstream of the filter elements.

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 present invention is directed to an exhaust gas treatment system and method for removing particulate matter and nitrogen oxides from diesel engine exhaust streams. More specifically, the present invention relates to an emission treatment system that effectively provides simultaneous treatment of the particulate matter, as well as the NOx and other gaseous components of diesel engine exhaust. The emission treatment system uses an integrated soot filter coated with a catalyst washcoat composition comprising sub-micron particles, thereby providing an ultra-thin sub-micron washcoat layer showing improved catalyst performance without causing excessive backpressure.

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.

By using catalytic partial oxidation or autothermal reforming process, a catalytic oxidizer installed in the engine's Exhaust Gas Recycle (EGR) line can be used to produce from fossil fuels or bio-fuels a reformate gas containing H2 and CO for an IC engine or a gas turbine. Thus, a system consisting of an EGR Oxidizer and an IC engine / gas turbine can be used by itself as a driving device, or can be combined with an electric generator and a battery bank to produce, store and transmit electricity to be used in stationary or mobile power generation, transportation and utility etc.The Oxidizer can also be used to provide reducing gases to regenerate the NOx or diesel particulate traps, so that the traps can continuously be used for reducing emissions from IC engine, diesel truck, gas turbine, power plant etc.

A diesel particulate filter (14) which traps particulate matter and a NOx trap catalyst (13) which traps nitrogen oxides are installed in series in an exhaust passage (10) of a diesel engine (1). A controller (21) calculates a particulate matter deposition amount in the diesel particulate filter (14) (S4). The controller (21), when the particulate matter deposition amount exceeds a first predetermined amount (PM2), prevents sharp increase of the particulate matter deposition amount by prohibiting rich spike where the oxygen concentration of the exhaust gas is controlled to a value corresponding to a rich air-fuel ratio in order to regenerate the NOx trap catalyst (13) (S301, S302, S306), and prevents the particulate matter deposition amount of the diesel particulate filter (14) from reaching a limit.

A diesel engine (1) provided with a NOx catalyst (28A) and a diesel particulate filter (28B) performs lean burn operation during normal running, rich burn operation during regeneration of the NOx catalyst (28A), operation under the stoichiometric air-fuel ratio during desulphating of the NOx catalyst (28A), and operation under a slightly lean air-fuel ratio to regenerate the filter after desulphating of the NOx catalyst (28A). When the lean burn operation is applied, a controller (31) first controls the fuel injection amount, and controls an air supply amount based on the fuel injection amount. When rich burn operation is applied, the controller (31) first controls the air supply amount and controls the fuel injection amount based on the air supply amount. Due to this control, the response of the excess air factor control is enhanced while preventing torque fluctuation accompanying the variation of the target excess air factor.

A method for operating an internal combustion engine (100) and exhaust system therefor includes the step of initiating a regeneration event in a diesel particulate filter (DPF 109) (401). A first oxygen concentration (213) of a gas upstream of the DPF 109, and a second oxygen concentration (215) of the gas downstream of the DPF 109 are sensed (403) to infer a rate of combustion of material in the DPF (405) based on the difference between the first (213) and the second (215) oxygen concentrations. The rate of combustion is compared to a threshold value (409) and the regeneration event in the DPF 109 is terminated (411) if the rate of combustion is above the threshold.

A catalyzed diesel particulate filter (CDPF) and a method for filtering particulates from diesel engine exhaust are provided, where the catalyzed diesel particulate filter includes a substrate and a catalyst composition, where the catalyst composition contains at least one first component, at least one second component, and at least one third component, where the first component is at least one first component selected from the group consisting of cerium and a lanthanide and mixtures thereof, the at least one second component is selected from the group consisting of cobalt, copper, manganese and mixtures thereof; and the third component comprises strontium, where the first component, the second component, and the third component are in an oxide form after calcination. The catalyst on the catalyzed diesel particulate filter lowers the temperature at which particulates are removed from the CDPF by oxidizing the particulates on the filter. The catalyzed diesel particulate filter may also include a washcoat. Washcoats prepared from colloidal aluminum oxide may have higher surface areas and pore volumes loadings than washcoats containing aluminum oxide prepared from aluminum nitrate.

A cordierite ceramic body having (i) a pore size distribution and a porosity which satisfy the relationship 10.2474 / [(d50)<2>(pore fraction)]+0.0366183(d90)-0.00040119(d90)<2>+0.468815(1 / pore fraction)<2>+0.0297715(d50)+1.61 639(d50-d10) / d50<=3.65, and (ii) a CTE (25°-800° C.) of <=15X10<-7> / ° C., wherein the cordierite ceramic body is produced from a moldable mixture comprising cordierite-forming raw materials including (a) a fine talc having a median particle diameter, as measured by laser diffraction, of less than 10 micrometers, and a B.E.T. specific surface area of greater than 5 m<2> / g, and (b) a pore former. The cordierite ceramic body is suitable in the fabrication of cellular, wall-flow diesel particulate filters having a low pressure drop, high filtration efficiency and improved strength.

A ceramic comprising predominately a cordierite-type phase approximating the stoichiometry Mg2Al4Si5O18 and having a coefficient of thermal expansion (25-800° C.) of greater than 4×10−7 / ° C. and less than 13×10−7 / ° C. and a permeability and a pore size distribution which satisfy the relation 2.108 (permeability)+18.511 (total pore volume)+0.1863 (percentage of total pore volume comprised of pores between 4 and 40 micrometers)>24.6. The ceramic is suitable in the fabrication of cellular, wall-flow, diesel particulate filters having a pressure drop in kPa that at an artificial carbon soot loading of 5 grams / liter and a flow rate of 26 scfm is less than 8.9-0.035 (number of cells per square inch)+300 (cell wall thickness in inches), a bulk filter density of at least 0.60 g / cm3 and a volumetric heat capacity of at least 0.67 J cm−3 K−1 as measured at 500° C.

A flow rate of gas supplied to a diesel particulate filter is increased when it is determined that rapid combustion of collected particulates, which are collected by the particulate filter, is likely to occur based on an operating state of an internal combustion engine. Alternatively, the flow rate of gas supplied to the filter is increased when it is determined that rapid combustion of the collected particulates is initiated based on a state of the particulate filter.

A diesel particulate filter assembly, including a housing having an inlet end and an outlet end, a particulate filter portion consisting essentially of mullite fibers and positioned in the housing, channels in the filter, a porous wall between adjacent channels, and an exhaust path extending through the inlet end, through the particulate filter portion and though the outlet end.

A system for filtering and oxidizing particulate matter produced by a gasoline direct injection engine is disclosed. In one embodiment, engine cylinder air-fuel is adjusted to allow soot to oxidize at an upstream particulate filter while exhaust gases are efficiently processed in a downstream catalyst.

Uncontrolled regeneration in a Diesel particulate filter is prevented by controlling the concentration and mass flowrate of oxygen passing through the Diesel particulate filter during regeneration.

The exhaust gas of internal combustion engines operated with a predominantly stoichiometric air / fuel mixture contains, as well as the gaseous hydrocarbon (HC), carbon monoxide (CO) and nitrogen oxide (NOx) pollutants, also ultrafine particulates. The introduction of the EU-5 exhaust gas standard in Europe in 2010 will for the first time impose a legal limit to these particulate emissions for gasoline vehicles. Future exhaust gas cleaning concepts for these vehicles must include devices for removing these particulates.A catalytically active particulate filter, an exhaust gas cleaning system and a process for cleaning the exhaust gases of predominantly stoichiometrically operated internal combustion engines are presented, which are suitable, as well as the gaseous CO, HC and NOx pollutants, also for removing particulates from the exhaust gas. The particulate filter comprises a filter body and a catalytically active coating consisting of two layers. Both layers contain alumina. The first layer contains palladium. The second layer contains rhodium. The latter is disposed above the first layer.

A single lean NOx trap (8) has an inlet manifold (10) with baffles (18–20) to divide the inlet manifold into three flow paths (11–13). Each flow path has a thermal reformer (24–26; CPO, (POX, or ATR) with an electric heater provided electric power by related lines (29–31). Fuel from a source (50) is controlled (45–46) to apply pulses of fuel through nozzles (40–42) into each corresponding path (11–13) in turn. A plurality of diesel particulate filters (14) are disposed in the flow paths (11–13) upstream of the lean NOx trap (8). A diesel oxidation catalyst (53) is disposed downstream of the lean NOx trap.

An exhaust gas treatment system for a diesel engine is disclosed. The exhaust gas treatment system includes a lean NOX trap (LNT) in fluid communication with a diesel engine to receive an exhaust gas flow therefrom. The system also includes a two-way catalyst in fluid communication with the LNT to receive the exhaust gas flow therefrom, the two-way catalyst comprising a urea selective catalytic reduction catalyst and a diesel particulate filter (DPF).

An exhaust gas treatment system for a diesel engine is disclosed. The exhaust gas treatment system includes a hydrocarbon selective catalytic reduction catalyst (HC-SCR) in fluid communication with a diesel engine to receive an exhaust gas flow therefrom. The system also includes a two-way catalyst in fluid communication with the HC-SCR to receive the exhaust gas flow therefrom, the two-way catalyst comprising a urea selective catalytic reduction catalyst and a diesel particulate filter (DPF).

A regeneration control method for regenerating a continuously regenerating diesel particulate filter device capable of regenerating a filter by efficiently removing PM while suppressing the deterioration of fuel consumption and preventing a drivability from being deteriorated, wherein the clogged-state of the filter is judged in three or more phases of the clogged-state and, when the clogged-state of the filter reaches a specified phase, a specified regenerating mode operation set in correspondence with the reached phase is performed.

Pollution control apparatus. An exhaust aftertreatment unit is fitted to the exhaust of an internal combustion engine and a fuel reformer provides hydrogen rich gas in an optimal way to the aftertreatment unit to regenerate the aftertreatment unit. It is preferred that the hydrogen rich gas be provided only to a portion of the aftertreatment unit at any time to regenerate that portion. Stored hydrogen may be used.

The present invention is directed to a filter cleaning device, in particular, diesel particulate filters. In one embodiment, the device comprises a source of high pressure fluid and means to transport the fluid to a nozzle or nozzles; an actuator for moving the nozzles; a controller with logic for instructing the actuator to automatically move the nozzle or nozzles across the surface of the filter; a collection device and suction device downstream of the filter; and ducting to transport the fluid between parts of the system. In one embodiment, a second collection device is used downstream of the suction device to provide additional particulate removal. There are three methods proposed for providing high pressure cleaning fluid to the filter face: 1) rotating the filter and rotating the jet about an axis outside of the filter; 2) moving a nozzle in two perpendicular directions (i.e., x-y); and 3) rotating a rectangular nozzle about the central axis of the filter.

The invention discloses a purification system of vent gas of diesel engine. The purification system of vent gas of diesel engine essentially consists of a wall-flow diesel particle filter (DPF) and a heating regeneration device used for regeneration of the wall-flow diesel particle filter (DPF). The heating regeneration device consists of an electronic control unit (ECU), a combustion chamber and an ignition system. The ignition system comprises a spark plug, a high voltage wire and an ignition coil, a combustion air generating device and relevant pipes, ejector components and pipes, an oil nozzle, relevant temperature and pressure sensor and other gas paths, a valve of oil circuit and an automatic protection device. Compared with the prior art, the invention is characterized by reliable regeneration, efficient purification and no restriction of the way vehicle driving, etc.

An apparatus, system, and method are disclosed for estimating particulate production from a diesel engine. Engine conditions such as fuel rate, exhaust gas recirculation, and fuel injection timing are determined. Based on empirical evidence or theoretical calculations, or both, particulate production markers, each indicating a level of particulate production, are assigned to each engine condition. The markers are combined and the combined marker is used to interpolate between a minimum and a maximum level of particulate production from the engine to estimate a particulate production rate. The production rate may be combined with an oxidation rate to determine a particulate accumulation rate, which may in turn be combined with a particulate load estimate to produce a combined particulate load estimate. The combined estimate may be used to determine whether to initiate regeneration of a diesel particulate filter.

High exhaust gas temperatures whereby sulfur is removed from a lean NOx traps simultaneously with regeneration of a Diesel particulate filter is provided by alternating engine operation in respectively defined lean and rich combustion modes. The duration and frequency of the respective lean and rich operating modes, as well as the air / fuel ratio during the respective modes, are preferably controlled by the sensed temperature of the lean NOx trap substrate.