EP4313366A1 - Procédé pour augmenter la filtration douce de filtres à particules d'essence - Google Patents

Procédé pour augmenter la filtration douce de filtres à particules d'essence

Info

Publication number
EP4313366A1
EP4313366A1 EP22720306.4A EP22720306A EP4313366A1 EP 4313366 A1 EP4313366 A1 EP 4313366A1 EP 22720306 A EP22720306 A EP 22720306A EP 4313366 A1 EP4313366 A1 EP 4313366A1
Authority
EP
European Patent Office
Prior art keywords
wall
filter
powder
exhaust gas
flow filter
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
EP22720306.4A
Other languages
German (de)
English (en)
Inventor
Jan Schoenhaber
Naina DEIBEL
Joerg-Michael Richter
Michael Schiffer
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Umicore AG and Co KG
Original Assignee
Umicore AG and Co KG
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Umicore AG and Co KG filed Critical Umicore AG and Co KG
Publication of EP4313366A1 publication Critical patent/EP4313366A1/fr
Pending legal-status Critical Current

Links

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
    • F01N3/02—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust
    • F01N3/021—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust by means of filters
    • F01N3/022—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust by means of filters characterised by specially adapted filtering structure, e.g. honeycomb, mesh or fibrous
    • F01N3/0222—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust by means of filters characterised by specially adapted filtering structure, e.g. honeycomb, mesh or fibrous the structure being monolithic, e.g. honeycombs
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D46/00—Filters or filtering processes specially modified for separating dispersed particles from gases or vapours
    • B01D46/24—Particle separators, e.g. dust precipitators, using rigid hollow filter bodies
    • B01D46/2403—Particle separators, e.g. dust precipitators, using rigid hollow filter bodies characterised by the physical shape or structure of the filtering element
    • B01D46/2418—Honeycomb filters
    • B01D46/2425—Honeycomb filters characterized by parameters related to the physical properties of the honeycomb structure material
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/34—Chemical or biological purification of waste gases
    • B01D53/92—Chemical or biological purification of waste gases of engine exhaust gases
    • B01D53/94—Chemical or biological purification of waste gases of engine exhaust gases by catalytic processes
    • B01D53/9445—Simultaneously removing carbon monoxide, hydrocarbons or nitrogen oxides making use of three-way catalysts [TWC] or four-way-catalysts [FWC]
    • B01D53/9454—Simultaneously removing carbon monoxide, hydrocarbons or nitrogen oxides making use of three-way catalysts [TWC] or four-way-catalysts [FWC] characterised by a specific device
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2255/00—Catalysts
    • B01D2255/90—Physical characteristics of catalysts
    • B01D2255/915—Catalyst supported on particulate filters
    • B01D2255/9155—Wall flow filters
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2258/00—Sources of waste gases
    • B01D2258/01—Engine exhaust gases
    • B01D2258/012—Diesel engines and lean burn gasoline engines
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/34—Chemical or biological purification of waste gases
    • B01D53/92—Chemical or biological purification of waste gases of engine exhaust gases
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/34—Chemical or biological purification of waste gases
    • B01D53/92—Chemical or biological purification of waste gases of engine exhaust gases
    • B01D53/94—Chemical or biological purification of waste gases of engine exhaust gases by catalytic processes
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N2260/00—Exhaust treating devices having provisions not otherwise provided for
    • F01N2260/06—Exhaust treating devices having provisions not otherwise provided for for improving exhaust evacuation or circulation, or reducing back-pressure
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N2260/00—Exhaust treating devices having provisions not otherwise provided for
    • F01N2260/14—Exhaust treating devices having provisions not otherwise provided for for modifying or adapting flow area or back-pressure
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N2330/00—Structure of catalyst support or particle filter
    • F01N2330/06—Ceramic, e.g. monoliths
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N2510/00—Surface coverings
    • F01N2510/06—Surface coverings for exhaust purification, e.g. catalytic reaction

Definitions

  • the present invention is directed to a wall flow filter. This contains a powder coating, which only increases the filtration efficiency when it is fresh. Also claimed is an exhaust system which has such a wall-flow filter.
  • the exhaust gas from internal combustion engines in motor vehicles typically contains the pollutant gases carbon monoxide (CO) and hydrocarbons (HC), nitrogen oxides (NO x ) and possibly sulfur oxides (SO x ), as well as particles, which largely consist of solid carbonaceous particles and possibly adhering organic agglomerates . These are referred to as primary emissions.
  • CO, HC and particles are products of the incomplete combustion of fuel in the engine's combustion chamber.
  • Nitrogen oxides are formed in the cylinder from nitrogen and oxygen in the intake air when the combustion temperatures exceed 1200°C. Sulfur oxides result from the combustion of organic sulfur compounds, which are always present in small amounts in non-synthetic fuels.
  • the flow-through or wall-flow honeycomb bodies just described are also referred to as catalyst carriers, carriers or substrate monoliths, since they carry the catalytically active coating on their surface or in the walls forming this surface.
  • the catalytically active coating is often applied to the catalyst support in a so-called coating process in the form of a suspension. Many such processes are in the past of automotive catalytic converter manufacturers been published on this (EP1064094B1, EP2521618B1, W010015573A2,
  • the operating mode of the internal combustion engine is decisive for the possible methods of pollutant conversion in the catalytic converter.
  • Diesel engines are usually operated with excess air, most petrol engines with a stoichiometric mixture of intake air and fuel. Stoichiometric means that on average there is just as much air available to burn the fuel in the cylinder as is required for complete combustion.
  • the combustion air ratio l (A/F ratio; air/fuel ratio) relates the air mass mi_,tats actually available for combustion to the stoichiometric air mass mi_,st:
  • lean-burn motor vehicle engines Insofar as lean-burn motor vehicle engines are mentioned in the present text, reference is hereby mainly made to diesel engines and predominantly lean-burn Otto engines on average.
  • the latter are predominantly gasoline engines operated with an average lean A/F (air/fuel) ratio.
  • most gasoline engines are mainly operated with a combustion mixture that is stoichiometric on average.
  • This change in the air ratio l is essential for the exhaust gas cleaning result.
  • the exhaust gas can therefore be described as “on average” stoichiometric. So that these deviations do not have a negative impact on the exhaust gas cleaning result when the exhaust gas is transferred via the Affect three-way catalyst, the oxygen storage materials contained in the three-way catalyst compensate for these deviations by absorbing oxygen from the exhaust gas as required or releasing it into the exhaust gas (R.
  • the pollutant gases carbon monoxide and hydrocarbons can be rendered harmless from a lean exhaust gas by oxidation on a suitable oxidation catalytic converter.
  • all three pollutant gases HC, CO and NOx
  • all three pollutant gases can be eliminated via a three-way catalytic converter.
  • the reduction of nitrogen oxides to nitrogen (“denitrification" of the exhaust gas) is more difficult due to the high oxygen content of a lean-burn engine.
  • a well-known method here is the selective catalytic reduction of nitrogen oxides (Selective Catalytic Reduction; SCR) on a suitable catalyst, called SCR catalyst for short. This method is currently considered to be preferred for the denitrification of lean-burn engine exhaust gases.
  • the nitrogen oxides contained in the exhaust gas are reduced in the SCR process with the aid of a reducing agent dosed into the exhaust line from an external source.
  • Ammonia is used as a reducing agent, which converts the nitrogen oxides in the exhaust gas to nitrogen and water in the SCR catalytic converter.
  • the ammonia used as a reducing agent can be made available by metering an ammonia precursor compound, such as urea, ammonium carbamate or ammonium formate, into the exhaust system and subsequent hydrolysis.
  • Diesel particle filters (DPF) or petrol particle filters (GPF)/otton particle filters (OPF) with and without an additional catalytically active coating are suitable units for removing particle emissions.
  • DPF diesel particle filters
  • GPF petrol particle filters
  • OPF otton particle filters
  • a particulate filter - whether catalytically coated or not - leads to a noticeable increase in exhaust back pressure compared to a flow carrier of the same dimensions and thus to a reduction in engine torque or possibly increased fuel consumption.
  • the quantities of oxidic support materials for the catalytically active elements of the catalyst or oxidic catalyst materials are generally applied in smaller quantities in a filter than in a flow carrier.
  • the catalytic effectiveness of a coated particle filter is often inferior to that of a flow monolith of the same size.
  • the catalytically active coating is not located as a layer on the wall of a porous wall-flow filter, but instead permeates the wall of the filter with the catalytically active material (WO2005016497A1, JPH01-151706, EP1789190B1).
  • the particle size of the catalytic coating is chosen so that the particles penetrate into the pores of the wall flow filter and can be fixed there by calcination.
  • a filtration layer (“discriminating layer”) is created on the walls of the flow channels on the inlet side by depositing ceramic particles via a particle aerosol.
  • the layers consist of oxides of zirconium, aluminum or silicon, preferably in the form of fibers from 1 nm to 5 ⁇ m and have a layer thickness of more than 10 ⁇ m, generally 25 ⁇ m to 75 ⁇ m.
  • a coating within the pores of a wall flow filter unit by means of atomizing dry particles is described in US Pat. No. 8,388,721 B2.
  • the powder should penetrate deep into the pores. 20% to 60% of the surface of the wall should be accessible to soot particles, i.e. remain open.
  • soot particles i.e. remain open.
  • a more or less strong powder gradient can be set between the inlet and outlet side.
  • aluminum oxide particles containing gas stream Derge stalt coated that the complete particles having a particle size of 0.1 pm to 5 pm deposited as a porous filling in the pores of the wall flow filter who the.
  • the particles themselves can implement a further functionality of the filter in addition to the filter effect.
  • these particles are deposited in the pores of the filter in an amount of more than 80 g/l based on the filter volume. They fill 10% to 50% of the volume of the filled pores in the canal walls. Both with soot and without soot, this filter has an improved filtration efficiency compared to the untreated filter with a lower exhaust back pressure of the filter loaded with soot.
  • EP2502661A1 and EP2502662B1 further processes for the application of powder coating to filters are mentioned.
  • Corresponding apparatuses for subjecting the filter to a powder-gas aerosol are also shown there, in which the powder applicator and the wall-flow filter are each separated in such a way that air is sucked in through this space during coating.
  • a membrane (“trapping layer”) is produced on the surfaces of the inlet channels of filters to increase the filtration efficiency of catalytically inactive wall-flow filters is described in patent specification US8277880B2.
  • the filtration membrane on the surfaces of the inlet channels is realized by sucking through a gas flow loaded with ceramic particles (e.g. silicon carbide, cordierite).
  • the honeycomb body is fired at temperatures above 1000°C in order to increase the adhesive strength of the powder layer on the channel walls.
  • WO2011151711 A1 describes a method with which a non-coated or catalytically coated filter is exposed to a dry aerosol.
  • the aerosol is provided by dispersing a powdered high-melting metal oxide with an average particle size of 0.2 ⁇ m to 5 ⁇ m and guided by means of a gas stream over the inlet side of a wall-flow filter.
  • the individual particles agglomerate to form a bridged network of particles and are deposited as a layer on the surface of the individual inlet channels running through the wall flow filter.
  • the typical loading of a filter with the powder is between 5 g and 50 g per liter of filter volume. It is expressly pointed out that that it is not desirable to coat the pores of the wall-flow filter with the metal oxide.
  • GPF gasoline particulate filters
  • OPF gasoline particulate filters
  • Such Fil ter usually have a particularly high exhaust back pressure, which - as ge says - can lead to reduced engine performance and / or increased fuel consumption. Oil ash and soot particles that are deposited during operation inevitably lead to a further increase in exhaust back pressure and filtration performance (Fig. 2 for stable powder).
  • Claim 8 relates to an exhaust system according to the invention.
  • the subclaims dependent on these claims are directed to preferred embodiments of the wall-flow filter or the exhaust gas system according to the invention.
  • thermolabile powder on and/or in its input surface, which increases the filtration efficiency of the filter when it is fresh and its surface or volume when properly Operation of the filter decreases in such a way that an increase in the exhaust back pressure compared to a filter that has not been treated with the thermolabile powder by a maximum of 10% after an equivalent exposure to particulate exhaust gas components is recorded, this can be achieved very easily and elegantly, but not for that less surprising to solve the task.
  • the thermal load on the filter in normal operation and during regeneration phases reduces the surface area and volume of the thermolabile powder, so that the proportion of the powder coating in the total back pressure slowly decreases over time. Since the filter at the same time, for example If oil ash accumulates, the filtration performance remains largely unchanged, despite the decrease in surface area and volume of the thermolabile powder (Fig. 1/2).
  • Porous wall flow filter substrates made of cordierite, silicon carbide or aluminum titanate are preferably used. These wall-flow filter substrates have inflow and outflow channels, with the outflow-side ends of the inflow channels and the inflow-side ends of the outflow channels being offset from one another and sealed with gas-tight “plugs”.
  • the exhaust gas to be cleaned which flows through the filter substrate, is forced to pass through the porous wall between the inflow and outflow channels, which results in an excellent particle filter effect.
  • the filtration properties for particles can be designed through the porosity, pore/radius distribution and thickness of the wall.
  • the porosity of the uncoated wall flow filter is usually more than 40%, generally from 40% to 75%, especially from 50% to 70% [measured according to DIN 66133 - latest version on the filing date].
  • the average pore size of the uncoated filters is at least 7 ⁇ m, e.g. B. from 7 pm to 34 pm, preferably more than 10 pm, in particular more preferably from 10 pm to 25 pm or very preferably from 15 pm to 20 pm [measured according to DIN 66134 latest version on the filing date].
  • the finished filters with a pore size of typically 10 ⁇ m to 20 ⁇ m and a porosity of 50% to 65% are particularly preferred.
  • thermolabile means the property of exhibiting instability under the influence of elevated temperatures.
  • the powder Before lying a thermolabile powder is used.
  • the powder therefore consists of a solid which undergoes a transformation under the action of sufficient heat energy in such a way that its density increases.
  • the volume and surface area of the powder decreases as a result of this heat effect.
  • the powder presents less volume or surface area to the incoming exhaust gas. Therefore, the exhaust back pressure of the filter decreases as described above. This decrease in exhaust back pressure is compensated for by the oil ash that accumulates in the filter over time and cannot be removed.
  • thermolability - ie the speed at which the powder loses its volume and surface - should correspond to this ideal as closely as possible.
  • the thermolabile powder should therefore preferably show a reduction in surface area of 15-50%, preferably 20-40% and most preferably 25-35% after aging for 6 hours in the oven in the presence of air at 1000°C.
  • thermolabile powder in the present invention runs counter to the trend that normally high surface area carrier substances for catalytically active metals are used in car exhaust gas catalysts, which have a surface which is as thermostable as possible. Because the more stable the surface, the less subject a catalyst is to thermally induced aging through sintering of the carrier oxide. In the present case, however, it is a question of allowing such a high-surface area powder to age thermally in a targeted manner.
  • the same substances can be used for the present inventions that also serve as normal carrier oxides in car exhaust gas catalysts, provided they are in a form that has a thermal stability as characterized above.
  • the powder is preferably high-surface oxides of metals, for example those selected from the group consisting of aluminum oxide, silicon dioxide, cerium oxide, zirconium oxide, titanium dioxide or mixtures or mixed oxides (solid solutions) thereof.
  • the oxides are preferably not doped with other metals, which leads to better stability.
  • the thermolabile powder is more preferably aluminum oxide, very preferably an undoped aluminum oxide or mixed oxides of aluminum oxide and silicon oxide, such as zeolites.
  • zeolites can be selected or synthesized in a way that is tailor-made for the problem at hand in terms of their structure.
  • oxides with a high surface area this means oxides with a BET surface area of more than 10 m 2 /g, preferably more than 30 m 2 /g and very particularly preferably more than 50 m 2 /g .
  • BET surface area of more than 10 m 2 /g, preferably more than 30 m 2 /g and very particularly preferably more than 50 m 2 /g .
  • the person skilled in the art knows how to obtain such oxides.
  • the filter according to the invention can be manufactured according to methods which are described above as prior art.
  • a metal oxide powder for example, is generally mixed with a gas (http://www.tsi.com/Aerosolgeneratoren-und-disperqierer/; https://www.palas.de/de/product/aerosolgeneratorssolidparticles).
  • This mixture of the gas and the powder produced in this way is then advantageously conducted via a gas flow into the inlet side of the wall-flow filter.
  • the part of the filter formed by the inflow channels/inlet channels is seen on the inlet side.
  • the entrance surface is defined by the wall surfaces of the inflow ducts/entrance ducts formed on the inlet side of the wall flow filter. The same applies to the outlet side.
  • gases suitable for the person skilled in the art for the present purpose can be used as gases for the production of the aerosol and for the introduction into the filter.
  • air is very particularly preferred.
  • other reaction gases can also be used which can develop either an oxidizing (e.g. O2, NO2) or a reducing (e.g. H2) activity towards the powder used.
  • inert gases e.g. N2
  • noble gases e.g. He
  • the aerosol preferably has a speed of 5 m/s to 50 m/s, more preferably 10 m/s to 40 m/s and very particularly preferably 15 m/s up to 35 m/s is sucked through the filter. This also achieves advantageous adhesion of the applied powder.
  • a wall-flow filter manufactured according to the method outlined above should preferably have the powder in the large pores, since these are mainly responsible for the poor filtration efficiency of the filter. For this purpose it is preferred if the powder does not fall below a certain particle size (measured according to the latest ISO 13320-1 on the filing date).
  • the D50 values of the powder are usually between 1 and 5 ⁇ m, preferably between 2 and 4 ⁇ m and very particularly preferably around 3 ⁇ m. This preferably blocks the large pores of the filter, so that it has a significantly increased filtration performance, but also a greater back pressure than the raw substrate.
  • the filtration efficiency of the filter containing powder should correspond as closely as possible to that which results after the oil ash has been deposited after proper operation.
  • the filtration efficiency of the filter containing powder in the fresh state is between 85% and 99.9%, preferably >87% and most preferably >90%.
  • Those skilled in the art know how to determine filtration efficiency.
  • Another key factor in how this filtration efficiency can be achieved is the amount of powder to be separated in the wall flow filter. It should not be too high in order not to create excessive exhaust gas back pressure of the filter when fresh, but it should be high enough to achieve the targeted fresh filtration efficiency.
  • the powder should be applied to the filter in an amount of 1-40 g/l, preferably 1.5-30 g/l and very preferably 2-25 g/l.
  • the comparison envisaged according to the invention with regard to the exhaust gas back pressure of a wall flow filter treated according to the invention with thermolabile powder and an untreated filter of the same type in which the exhaust gas back pressure increases by a maximum of 10%, preferably a maximum of 7% and particularly preferably a maximum of 5% increase should be done after a period of proper operation of the filter.
  • the filter has then already undergone several filter regenerations and the applied powder should no longer change its volume or its surface due to the effect of heat at this point.
  • the filter regenerations can also be artificially simulated in appropriate systems. Before geous way, the increase in the exhaust back pressure for the specified comparison is determined immediately after 10 active soot regenerations. Temperatures of approx.
  • 700 - 800 °C act on the filter for 5 - 10 minutes during each regeneration. This should be sufficient to allow maximum sintering of powder in the pores of the wall flow filter.
  • the test to be assessed here is advantageously based on 10 filter regenerations, each lasting 10 minutes and during which the filter is exposed to a temperature of at least 800°C for 5 minutes. In the case of artificially induced tests, the amount of ash must therefore be dimensioned accordingly so that such a temperature curve can be ensured.
  • the filter can have been catalytically coated before being subjected to the powder/gas aerosol.
  • catalytic coating means the ability to convert harmful components of the exhaust gas from internal combustion engines into less harmful ones.
  • the exhaust gas components NOx, CO and HC as well as particles should be mentioned here.
  • this catalytic activity is provided by coating the wall-flow filter with a catalytically active material.
  • coating is accordingly understood to mean the application of catalytically active materials to the wall flow filter. The coating takes on the actual catalytic function.
  • the coating is carried out by applying a correspondingly low-viscosity aqueous suspension—also called a washcoat—or a solution of the catalytically active components to the wall-flow filter, see e.g. B. according to EP1789190B1.
  • a correspondingly low-viscosity aqueous suspension also called a washcoat
  • a solution of the catalytically active components to the wall-flow filter, see e.g. B. according to EP1789190B1.
  • the wall-flow filter is dried and, if necessary, calcined at elevated temperature.
  • the catalytically coated filter preferably has a loading of 20 g/l to 200 g/l, preferably 30 g/l to 150 g/l.
  • the most suitable loading level of a wall-coated filter depends on its cell density, wall thickness and porosity.
  • the preferred load is 20 g/l to 50 g/l (related to the outer volume of the filter substrate).
  • Highly porous filters (>60% porosity) with, for example, 300 cpsi and 8 mil have a preferred loading amount of 25 g/l to 150 g/l, particularly preferably 50 g/l to 100 g/l.
  • the catalytic coating of the filter can preferably be selected from the group consisting of a three-way catalytic converter, SCR catalytic converter, nitrogen oxide storage catalytic converter, oxidation catalytic converter, and soot ignition coating.
  • a catalytically active coating comprising at least one metal ion-exchanged zeolite, cerium/zirconium mixed oxide, aluminum oxide and palladium, rhodium or platinum or combinations of these noble metals.
  • the present invention also relates to an exhaust system having a wall flow filter according to the invention and at least one other unit for reducing harmful exhaust gas components selected from the group consisting of oxidation catalyst, three-way catalyst, SCR catalyst, hydrocarbon trap and ammonia blocking catalyst.
  • the use of an exhaust gas system is particularly preferred which has a three-way catalytic converter close to the engine and a wall-flow filter according to the invention, also positioned close to the engine and provided with a three-way catalytic coating. It is also preferred if the exhaust gas system has a wall flow filter according to the invention provided with a three-way catalytic coating located in the underbody of the vehicle downstream of the close-coupled three-way catalytic converter.
  • close-coupled is an arrangement of the catalytic converter at a distance from the exhaust gas outlet of the cylinder of the engine of less than 120 cm, preferably less than 100 cm and very particularly preferably less than 50 cm.
  • the catalytic converter close to the engine is preferably arranged directly after the exhaust manifold is merged into the exhaust pipe.
  • Alumina stabilized with lanthana was combined with a first oxygen storage component comprising 40% by weight ceria, zirconia, lanthana and praseodymia and a second oxygen storage component comprising 24% by weight ceria, zirconia, lanthana and yttria. suspended in water. Both oxygen storage components were used in equal parts. The weight ratio of alumina and oxygen storage component was 30:70. A palladium nitrate solution and a rhodium nitrate solution were then added to the suspension thus obtained, with constant stirring. The resulting coating suspension was used directly for coating a commercially available wall-flow filter substrate, with the coating being introduced into the porous filter wall over 100% of the substrate length.
  • the total loading of this filter was 75 g/l, the total precious metal loading was 1.986 g/l with a ratio of palladium to rhodium of 5:1.
  • the coated filter obtained in this way was dried and then calcined. It is hereinafter referred to as VGPF1.
  • Alumina stabilized with lanthana was combined with a first oxygen storage component comprising 40% by weight ceria, zirconia, lanthana and praseodymia and a second oxygen storage component comprising 24% by weight ceria, zirconia, lanthana and yttria. suspended in water. Both oxygen storage components were used in equal parts. The weight ratio of alumina and oxygen storage component was 30:70. A palladium nitrate solution and a rhodium nitrate solution were then added to the suspension thus obtained, with constant stirring. The resulting coating suspension was used directly for coating a commercially available wall-flow filter substrate, with the coating being introduced into the porous filter wall over 100% of the substrate length.
  • the total loading of this filter was 75 g/l, the total precious metal loading was 1.986 g/l with a ratio of palladium to rhodium of 5:1.
  • the coated filter obtained in this way was dried and then calcined.
  • This filter was then sprayed with an aerosol (powder-gas mixture) coated, in which 7 g/l aluminum oxide were deposited on the filter.
  • This filter is hereinafter referred to as GPF1.
  • the VGPFl and the GPFl were then characterized with regard to their physical properties, filtration efficiency and back pressure behavior.
  • the back pressure of the two filters was measured on the cold gas test stand at a volume flow of 600 m 3 /h.
  • the filter VGPF1 had a pressure loss of 36.4 mbar, while the filter GPF1 according to the invention had a correspondingly higher back pressure of 42 mbar. This difference corresponds to a 15% increase in the back pressure of GPF1 over VGPF1, which is due to the deposition of the alumina.
  • the two filters were then examined on the engine test bench with regard to their filtration performance.
  • the filters were installed in the exhaust system in a position close to the engine, on the downstream side of a conventional three-way catalytic converter, and measured between two particle counters in the so-called WLTP cycle.
  • the filter VGPF1 showed a filtration efficiency of 60%, while the filter according to the invention had a filtration efficiency of 76% due to the filtration efficiency-increasing coating.
  • the filter GPF1 was then tempered for 10 hours at 1100°C in an air atmosphere and then measured again. It was found that after the temperature exposure on the cold gas test stand, the filter had a back pressure of only 37.1 mbar with the same volume flow as before. This corresponds to a back pressure increase of only 2% compared to the VGPF1. Although the back pressure of the filter has decreased after the temperature treatment, the filter still has an unchanged high filtration performance. This method is therefore ideally suited for providing filters that have an initially increased filtration performance and maintain this during continuous operation and at the same time have an ever-decreasing back pressure during operation due to the sintering of the filtration efficiency material.

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  • Engineering & Computer Science (AREA)
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  • Chemical Kinetics & Catalysis (AREA)
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Abstract

La présente invention concerne un filtre à écoulement sur paroi. Ledit filtre à écoulement sur paroi contient un revêtement en poudre qui augmente l'efficacité de filtration uniquement à l'état doux. L'invention concerne également un système de gaz d'échappement comprenant un tel filtre à écoulement sur paroi.
EP22720306.4A 2021-03-23 2022-03-22 Procédé pour augmenter la filtration douce de filtres à particules d'essence Pending EP4313366A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE102021107130.5A DE102021107130B4 (de) 2021-03-23 2021-03-23 Vorrichtung zur Erhöhung der Frischfiltration von Benzinpartikelfiltern
PCT/EP2022/057428 WO2022200311A1 (fr) 2021-03-23 2022-03-22 Procédé pour augmenter la filtration douce de filtres à particules d'essence

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EP4313366A1 true EP4313366A1 (fr) 2024-02-07

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US (1) US20240159175A1 (fr)
EP (1) EP4313366A1 (fr)
CN (1) CN117083118A (fr)
DE (1) DE102021107130B4 (fr)
WO (1) WO2022200311A1 (fr)

Family Cites Families (25)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4609563A (en) 1985-02-28 1986-09-02 Engelhard Corporation Metered charge system for catalytic coating of a substrate
JPH01151706A (ja) 1987-12-08 1989-06-14 Toyota Central Res & Dev Lab Inc 可燃性微粒子と窒素酸化物を除去するための触媒及びフィルター
GB9805815D0 (en) 1998-03-19 1998-05-13 Johnson Matthey Plc Manufacturing process
US6478874B1 (en) 1999-08-06 2002-11-12 Engelhard Corporation System for catalytic coating of a substrate
DE10014547B4 (de) 2000-03-23 2005-09-29 Umicore Ag & Co. Kg Verfahren zum teilweisen Beschichten eines Tragkörpers
US7229597B2 (en) 2003-08-05 2007-06-12 Basfd Catalysts Llc Catalyzed SCR filter and emission treatment system
DE102004040551A1 (de) 2004-08-21 2006-02-23 Umicore Ag & Co. Kg Verfahren zur Beschichtung eines Wandflußfilters mit einer Beschichtungszusammensetzung
WO2008066167A1 (fr) 2006-11-30 2008-06-05 Hitachi Metals, Ltd. Filtre céramique en nid d'abeilles et son procédé de fabrication
JP5378659B2 (ja) 2007-06-07 2013-12-25 株式会社キャタラー 貴金属担持方法
CN102170969B (zh) 2008-08-06 2013-09-11 巴斯夫欧洲公司 带有用于基于整件的汽车用和化学催化剂的旋转分度台的定位设备和方法
CN102223951A (zh) 2008-11-21 2011-10-19 日产自动车株式会社 粒状物净化材料、使用粒状物净化材料的粒状物净化用过滤器催化剂以及粒状物净化用过滤器催化剂的再生方法
EP2415522B2 (fr) 2009-04-03 2021-06-23 Cataler Corporation Procédé et dispositif de fabrication d'un catalyseur de contrôle d'émission de gaz d'échappement
GB201000019D0 (en) 2010-01-04 2010-02-17 Johnson Matthey Plc Coating a monolith substrate with catalyst component
JP5524696B2 (ja) 2010-04-22 2014-06-18 日本碍子株式会社 目封止ハニカム構造体の製造方法
GB201100595D0 (en) 2010-06-02 2011-03-02 Johnson Matthey Plc Filtration improvements
CN103270002B (zh) 2010-09-01 2017-06-13 陶氏环球技术有限责任公司 经由气体运载的多孔组件在多孔陶瓷过滤器上施加区别层的方法
JP5597153B2 (ja) 2011-03-24 2014-10-01 日本碍子株式会社 ハニカムフィルタ及びその製造方法
JP5643692B2 (ja) 2011-03-25 2014-12-17 日本碍子株式会社 ハニカムフィルタ及びその製造方法
GB201207313D0 (en) 2012-04-24 2012-06-13 Johnson Matthey Plc Filter substrate comprising three-way catalyst
DE102012220181A1 (de) 2012-11-06 2014-05-08 Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V. Partikelfilter
JP6177570B2 (ja) 2013-04-12 2017-08-09 株式会社キャタラー スラリー塗布装置
DE102018108346A1 (de) * 2018-04-09 2019-10-10 Umicore Ag & Co. Kg Beschichteter Wandflussfilter
DE102018110804B4 (de) * 2018-05-04 2024-06-27 Umicore Ag & Co. Kg Beschichteter Wandflussfilter
DE102018127953A1 (de) * 2018-11-08 2020-05-14 Umicore Ag & Co. Kg Wandflussfilter mit hoher Filtrationseffizienz
GB201911702D0 (en) * 2019-08-15 2019-10-02 Johnson Matthey Plc Particulate filters

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CN117083118A (zh) 2023-11-17
DE102021107130A1 (de) 2022-09-29
US20240159175A1 (en) 2024-05-16
DE102021107130B4 (de) 2022-12-29
WO2022200311A1 (fr) 2022-09-29

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