Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J35/00—Catalysts, in general, characterised by their form or physical properties
  • B01J35/50—Catalysts, in general, characterised by their form or physical properties characterised by their shape or configuration
  • B01J35/56—Foraminous structures having flow-through passages or channels, e.g. grids or three-dimensional monoliths
• • 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]
  • B01D53/945—Simultaneously removing carbon monoxide, hydrocarbons or nitrogen oxides making use of three-way catalysts [TWC] or four-way-catalysts [FWC] characterised by a specific catalyst
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
  • B01J23/38—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of noble metals
  • B01J23/54—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of noble metals combined with metals, oxides or hydroxides provided for in groups B01J23/02 - B01J23/36
  • B01J23/56—Platinum group metals
  • B01J23/63—Platinum group metals with rare earths or actinides
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J35/00—Catalysts, in general, characterised by their form or physical properties
  • B01J35/40—Catalysts, in general, characterised by their form or physical properties characterised by dimensions, e.g. grain size
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
  • B01J37/02—Impregnation, coating or precipitation
  • B01J37/0201—Impregnation
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
  • B01J37/02—Impregnation, coating or precipitation
  • B01J37/0201—Impregnation
  • B01J37/0205—Impregnation in several steps
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
  • B01J37/02—Impregnation, coating or precipitation
  • B01J37/0201—Impregnation
  • B01J37/0211—Impregnation using a colloidal suspension
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
  • B01J37/02—Impregnation, coating or precipitation
  • B01J37/0215—Coating
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
  • B01J37/02—Impregnation, coating or precipitation
  • B01J37/0234—Impregnation and coating simultaneously
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
  • B01J37/02—Impregnation, coating or precipitation
  • B01J37/024—Multiple impregnation or coating
  • B01J37/0242—Coating followed by impregnation
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D2255/00—Catalysts
  • B01D2255/10—Noble metals or compounds thereof
  • B01D2255/102—Platinum group metals
  • B01D2255/1021—Platinum
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D2255/00—Catalysts
  • B01D2255/10—Noble metals or compounds thereof
  • B01D2255/102—Platinum group metals
  • B01D2255/1023—Palladium
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D2255/00—Catalysts
  • B01D2255/10—Noble metals or compounds thereof
  • B01D2255/102—Platinum group metals
  • B01D2255/1025—Rhodium
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D2255/00—Catalysts
  • B01D2255/20—Metals or compounds thereof
  • B01D2255/204—Alkaline earth metals
  • B01D2255/2042—Barium
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D2255/00—Catalysts
  • B01D2255/20—Metals or compounds thereof
  • B01D2255/209—Other metals
  • B01D2255/2092—Aluminium
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D2255/00—Catalysts
  • B01D2255/40—Mixed oxides
  • B01D2255/407—Zr-Ce mixed oxides
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D2279/00—Filters adapted for separating dispersed particles from gases or vapours specially modified for specific uses
  • B01D2279/30—Filters adapted for separating dispersed particles from gases or vapours specially modified for specific uses for treatment of exhaust gases from IC Engines
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
  • Y02T10/00—Road transport of goods or passengers
  • Y02T10/10—Internal combustion engine [ICE] based vehicles
  • Y02T10/12—Improving ICE efficiencies

Definitions

• the present invention relates to a process for impregnating a porous body with a suspension, in particular a monolithic body with a honeycomb structure and an installation for using such a method.
• It relates more particularly to a monolith of a porous ceramic material used for the filtration of a gaseous stream or a liquid stream.
• the invention aims especially but not exclusively a coating process of a porous body used as particulate filter (FAP) for the exhaust gas of an internal combustion engine, especially diesel type.
• FAP particulate filter
• the exhaust gases of a diesel-type internal combustion engine comprise particles or soot that are released into the atmosphere and such discharges are harmful to human health. These gases also include other pollutants, such as carbon oxides CO, nitrogen oxides NOx (nitric oxide NO and nitrogen dioxide NO 2 ) and unburned HC hydrocarbons, which are released into the atmosphere untreated, and thereby also affect the health of man.
• pollutants such as carbon oxides CO, nitrogen oxides NOx (nitric oxide NO and nitrogen dioxide NO 2 ) and unburned HC hydrocarbons, which are released into the atmosphere untreated, and thereby also affect the health of man.
• treatment systems for these pollutants are implemented on certain engines and are better known under the name of catalysed FAP that can treat all or part of the pollutants contained in the exhaust gas.
• the treatment of the particles is carried out by trapping and then oxidation of the trapped particles
• the treatment of HC and CO can be carried out by catalytic oxidation reaction and the treatment of NOx by adsorption and then catalytic desorption / reduction or selective catalytic reduction.
• a catalyzed filter consisting of a monolithic body made of a refractory porous material and having a plurality of channels disposed between the two end faces of this body.
• the channels are placed in the direction of the gas stream to be treated and are separated from each other by porous partitions. These channels are alternately plugged, at the faces of the body, at one or the other of their ends so as to form inlet channels with open ends facing the gas stream and the outlet channels with blocked ends opposite this same gas flow.
• this stream of exhaust gas enters the inlet channels and then passes through the porous partitions separating the inlet channels of the outlet channels and then emerge through these outlet channels.
• the particles contained in the gas stream are retained on the walls and the gas flowing in the outlet channels is largely removed from these particles. These captured particles are then burned in situ, especially during an increase in the temperature of the exhaust gas flowing in the filter, so as to ensure the regeneration of the filter.
• the removal of the particles can be further facilitated by the addition of at least one catalytic or catalyst formulation, in particular a catalyst for oxidation of the particles.
• this catalyst is incorporated in the particulate filter, thus producing a catalyzed particulate filter which makes it possible to lower the oxidation temperature of the particles.
• the washcoat layer which is a solid film resulting from the drying and calcination operations of the body impregnated with a suspension containing a catalytic formulation, is deposited on the surface of the walls of the channels constituting the FAP.
• This has the disadvantage of significantly increasing the pressure drop when the amount of washcoat deposited is important.
• EP 1 338 322, EP 1 403 231 and US 2005/0056004 describe a method for incorporating a sol-gel type solution into the porosity of the FAP by impregnating solutions containing soluble precursors of the oxides. considered, which are then precipitated or hydrolysed / condensed, then dried and calcined.
• washcoat deposited within the porosity using these methods is however low, or even insufficient, or requires many successive deposition operations.
• WO 00/01463 describes an introduction of a suspension within the porosity of the FAP which has a very high porosity. Given this high porosity, the performance relative to particle filtration is minimal. Thus in order to achieve sufficient filtration efficiency, a filtration membrane having a smaller pore size distribution is added to the exit side of the FAP gas to stop the particles. This has the disadvantage of complicating the impregnation process and requiring the establishment of a membrane.
• the present invention proposes a simple impregnation method, inexpensive and whose quality of the deposition of the catalytic phases within the partitions can be controlled.
• the present invention relates to a process for impregnating a porous body with a suspension containing at least a portion of particles, said body comprising a multiplicity of channels delimited by porous partitions extending from one of the faces. to the other of the faces of said body, a portion of said channels being obstructed at one of the faces and the other part of the channels being obstructed at the other side, characterized in that the method comprises:
• the method may include exerting pressure on the introduced slurry.
• the method can also consist in exerting a depression on the introduced suspension.
• the process may consist in using a gas as a fluid.
• this process may consist in using an inert gas as a fluid. It may consist in producing at least one other suspension impregnation in the body.
• the method may include placing the other of the faces of the body in communication with a collector base.
• It may consist in connecting the collecting base to a suspension and / or fluid recovery device.
• the method may consist of placing the body in a sealed sheath.
• This process may include drying and calcining the body after impregnation.
• a porous body impregnated according to the process of the invention may be used to treat at least one pollutant contained in exhaust gases.
• porous body impregnated according to the process of the invention can be used for the filtration of liquid stream.
• the invention also relates to an installation for impregnating a porous body comprising an enclosure containing an impregnation suspension with at least a portion of particles, said enclosure being in communication with one of the faces of the body, characterized in that it comprises a device for pressurizing the enclosure.
• the installation may comprise a sealed sleeve for receiving the porous body.
• the installation may comprise a waterproofing membrane between the sheath and the body.
• This membrane may be an expandable membrane, in particular by inflation.
• the installation may comprise a collector base which may include means for evacuating the suspension.
• the Dvgo / Dpores ratio defined in the present invention is strictly positive. It may be preferentially greater than 0.001 and even more preferably greater than 0.01.
• FIG. 1 which is a diagram showing, in axial section, an impregnating installation using the method according to the invention
• FIG. 2 which illustrates a cross-section along the line AA of FIG. 1
• FIG. 3 which is a graph showing the evolution of the pressure drops as a function of the amount of washcoat obtained by the process according to the invention and by the method according to the prior art.
• FIG. 1 shows an installation 10 for impregnating with a suspension 12 a porous body 14.
• the body 14 is preferably a monolithic ceramic body with a honeycomb structure.
• the ceramic material may be silicon carbide, silicon nitride, cordierite, mullite, sialon, boron nitride, silica, alumina, aluminosilicates, aluminum titanate or zirconium phosphate and it can relate to a pure ceramic material (a single ceramic composition) or composite (several different ceramic compositions).
• This body comprises a multiplicity of substantially parallel channels 16 which extend from one end face 18 of this body to another end face 20. These channels are separated from each other by porous partitions 22 and can have any desired shape in section (circular, square, rectangular, triangular ). These channels comprise plugs 24 at one or the other of their ends so as to form input and output channels 28.
• the input channels comprise open ends at the face 18 and obstructed ends at the face 20 while the outlet channels 28 comprise clogged ends facing the face 18 and open ends opposite the face 20.
• this body can be used as catalyzed FAP to treat the pollutants (particles, CO, NOx and HC) contained in the exhaust gas of an internal combustion engine as a membrane for filtration / separation, such as the separation and / or filtration of liquid or gaseous material, such as the separation of hydrogen.
• pollutants particles, CO, NOx and HC
• This body may in particular have a number of channels ranging from 50 to 1100 channels per square inch.
• this number of channels per square inch may be between 50 and 600.
• the number of channels may range from 150 to 350 channels per square inch.
• the porosity of the partitions is 30 to 80% by volume and preferably 40 to 60% while the pore size distribution is 10 to 200 ⁇ m and preferably 20 to 50 ⁇ m.
• the impregnation installation comprises a vertical enclosure 30 with a casing 32 comprising an upper horizontal opening 34 and a lower horizontal opening 36 while considering FIG. 1.
• the upper opening 34 is closed by a cover 38 which is sealingly attached to this housing by any means, such as by screwing, with the interposition of a seal 40 between the cover and the rim of the opening of the housing.
• the lid carries a closed orifice 42 sealed by a plug 44 and which allows access to the interior of the chamber to pour the suspension 12 containing at least one catalytic phase.
• the lid also includes an intake manifold 46 of a pressurized fluid 48 within the enclosure and which is connected to a pressurizing installation 50 of the fluid.
• This installation comprises, in a manner known per se, a pressurizing pump and a fluid reservoir (not shown).
• this fluid is a gas, in particular air, and advantageously an inert gas, such as nitrogen, especially in the case where the suspension can evolve in an oxidizing or reducing atmosphere.
• the lid carries a relief valve 52 for discharging a portion of the pressurized fluid contained in the chamber in the case where the pressure in this chamber exceeds a limit pressure.
• a stop flange 54 extends radially inwardly of the housing.
• On the lower horizontal face of this collar rests, sealing, an upper end of a vertical receiving sleeve 56 in which is placed the body 14.
• the sleeve is placed vertically in the opening 36 and is immobilized against the collar by any means, such as screwing this sleeve into the opening, with the interposition of a seal 58 between the flange and the upper rim of the sleeve.
• the sheath is a tubular sheath whose inner dimensions correspond substantially to the outer dimensions of the body 14 so as to seal this body.
• the inner diameter of the sheath corresponds to the outer diameter of the body and the length of this sheath corresponds to at least the length of the body 14.
• a membrane (not shown) expandable, for example by inflation, can be arranged between the sheath and the body.
• the other end of the sheath is fixed, for example by screwing, on a collector base 60 while also bearing against sealing.
• This base advantageously in the form of a bowl, has a peripheral rim 62 rising towards the enclosure 30 and a bottom 64.
• the bottom 64 has a vertical discharge passage 66 disposed in the central region of the bottom and connected by a line 68 to a recovery device 70 of the suspension and / or pressurized gas.
• radial collector grooves 72 in the form of a portion of a cylinder or portion of Camembert which communicate with the passage 66 at their ends closest to this passage.
• these grooves are arranged at equal angular distance from each other, here at an angle of 30 °, and have the same section, leaving radial support strips 74 for the body 14.
• the The diameter of the circle circumscribed in these grooves is at least equal to the outside diameter of the body 14.
• a bearing surface 76, here annular, for the other end of the sheath is arranged in the continuity of the plane passing through the tops of the bars 74. between the inner face of the peripheral rim 62 of the base and the limit of the circle circumscribed to these grooves.
• This bearing surface has dimensions corresponding to the cross section of the sleeve with an inner diameter corresponding to that of the sleeve and an outer diameter at least equal to that of the outer diameter of the sleeve. It is therefore between the bearing surface 76 and the rim of the lower end of the sleeve that is disposed a seal 78 so as to seal between these two elements.
• the base 60 provided with its seal 78 is placed on a work surface and is connected to the recovery device 70.
• the lower end of the sleeve 56 is then placed on this base, then is screwed into the rim 62 until this end rests on the bearing surface 74 by compressing the seal 78.
• the body 14 is slid inside the sleeve 56 so that the face 20 of this body bears on the bars 74. In this position, the face 18 of the body 14 is preferably at the same level as the upper end of the sleeve 56.
• the enclosure 30 is then placed on the upper end of this sleeve then is screwed until the upper end bears against sealing on the radial flange 54 provided with its seal 58.
• the suspension 12, containing at least one catalytic phase, is introduced into the enclosure through the opening 42 and fills the input channels. This filling is continued to a level leaving a free space between the cover and this suspension.
• the realization of the suspension is such that the size distribution of the particles in the suspension, measured by laser diffraction, must be adapted to the size distribution of the pores of the body to allow the impregnation of the partition without clogging the pores.
• the ratio D V g / Dpores must be less than 0.25 to allow the impregnation of this body.
• the term DV ⁇ O refers to the dimension for which 90% of the particles in the suspension have a diameter (measured in volume by laser diffraction) smaller than this dimension whereas Dpores relates to the average pore size of the body, measured by mercury porosimetry. .
• the Dygo / Dpores ratio defined in the present invention is strictly positive when the term Dvgo is evaluated by volume measurements by laser diffraction.
• the ratio D V9 o / Dpores will be greater than 0.001 and even more preferably greater than 0.01.
• the orifice 42 is closed by the stopper 44 and the tubing 46, connected to the pressurizing installation 50, introduces the gas under pressure 48 into the free space of the enclosure 30.
• the suspension is pushed into the channels 26, until it passes through the porous partitions 22 to open into the outlet channels 28, as illustrated by the arrows in the figure 1.
• the suspension can not pass through the partitions located at the periphery of the body 14. In the following operational process the suspension, which has not been retained by the partitions, is pushed into the outlet channels 28 by the gas under pressure and ends in the grooves 72.
• the suspension is pushed by the gas into the evacuation passage 66 to be directed next through line 68 to the recovery device which may include a tray for receiving this suspension.
• the pressure is maintained in the chamber so that the gas passes through these partitions with a linear velocity of the gas in the channels (gas flow compared with to the total entrance surface of the body) between 2500 and 3000 m / h 1 .
• This allows the excess suspension to be evacuated contained in the pores of the heart of the partitions and perform a first drying of the film of the suspension deposited not only in the heart of these partitions but also on their peripheral surfaces.
• this pressurized gas circulates in the channels 28, the grooves 72 and the passage 66 to be either recovered by the recovery device 70 or vented to the atmosphere.
• the viscosity and the particle size distribution of this suspension are controlled, by the techniques known to those skilled in the art, in order to obtain a suspension satisfying the Dygo / Dpores ⁇ 0.25 and is sufficiently fluid to be forced through the walls of the FAP.
• the viscosity may be less than or equal to 20 mPa.s (measured at 1200 s -1 ).
• this viscosity is less than or equal to 15 mPa.s and even more preferably less than or equal to 10 mPa.s.Once these operations are completed, the pressurizing installation 50 is stopped and the enclosure is set to atmospheric pressure. The enclosure is then removed from the sheath 56 to be able to remove the body 14 of this sheath. This body is then dried in an oven and then calcined.
• the method described above makes it possible to insert solid particles into a porous body without blocking the porosity, judiciously choosing the textural properties of the porous body and adjusting the characteristics of the suspension used to insert the particles within the porosity of this porous body.
• a catalyst support of formulation 12% BaO, 18% CeO 2 , 13% ZrO 2 , 57% Al 2 ⁇ 3 (mass%) was prepared by co-precipitation of the corresponding nitrates.
• An aqueous suspension containing 30% of dry matter is prepared with this catalyst.
• the particle size is adjusted, by the techniques known to those skilled in the art, to obtain a ratio Dv ⁇ o / Dpores of 0.19.
• a porous body, usable as FAP, having a porosity of 40% is then impregnated in an operation according to the method of the invention by a sufficient amount of this suspension.
• a predrying is performed at room temperature by the gas with a drying LHSV in the range of 38000 h "1 p ⁇ iis PAF is dried in an oven at a temperature of about 150 0 C.
• a total charge of about 190 g / l of washcoat is obtained, with a pressure drop generated by this washcoat from 15mbar to 50000 h "1 .
• Precious metals are then impregnated on the FAP at a level of 1% Pt, 0.2% Pd and 0.2% Rh (% relative to the mass of washcoat deposited).
• a sol was prepared by mixing the salts of CeCl 2 , ZrOCl 2 , Ba (NO 3 ) 2 and boehmite at the concentrations necessary to obtain the same catalytic formulation as in the example of the process according to the invention. the invention.
• the FAP is immersed in this solution placed in a closed chamber, then the assembly is placed under vacuum to ensure a good wetting of all the pores of the FAP. This FAP is then drained, dried and calcined at 600 ° C. for
• FIG. 3 which shows the evolution of the pressure drops as a function of the amount of washcoat deposited by the process according to the invention (points and trend curve “invention”) and by the method of the prior art (points and trend curve D V go "prior art”), as described above.
• the losses of charge with high incorporation rate of the washcoat (of the order of 190 g / l) according to the process according to the invention are much lower, of the order of 15 mbar (millibars) than those of the process of the prior art which amount to more than 90 mbar.
• the incorporation of a large amount of washcoat (about 190 g / l) was carried out in a single operation according to the process of the invention, whereas the method according to the prior art requires more fifteen successive operations to obtain the same amount of washcoat.
• the porous filter body to be impregnated may be heat-treated or chemically treated in order to develop a thin oxide layer on the surface of the pores.
• This oxide layer makes it possible to obtain a strong adhesion of the washcoat on the body to be impregnated.
• the use of a suspension instead of a sol-gel for the impregnation of the body has the advantage of allowing the incorporation of any type of catalytic formulation (oxidation, SCR, DeNOx ...) within the porosity of this body. It is indeed possible, by the techniques those skilled in the art, to prepare a catalytic formulation dedicated to the intended application and then to prepare a suspension based on said formulation which has the necessary rheological characteristics to achieve the impregnation.

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• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Materials Engineering (AREA)
• Organic Chemistry (AREA)
• Health & Medical Sciences (AREA)
• Combustion & Propulsion (AREA)
• Biomedical Technology (AREA)
• Environmental & Geological Engineering (AREA)
• Analytical Chemistry (AREA)
• General Chemical & Material Sciences (AREA)
• Oil, Petroleum & Natural Gas (AREA)
• Catalysts (AREA)
• Solid-Sorbent Or Filter-Aiding Compositions (AREA)
• Manufacture Of Porous Articles, And Recovery And Treatment Of Waste Products (AREA)

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• 2006
  • 2006-08-18 FR FR0607399A patent/FR2904939B1/fr not_active Expired - Fee Related
• 2007
  • 2007-08-14 JP JP2009525087A patent/JP5547482B2/ja not_active Expired - Fee Related
  • 2007-08-14 WO PCT/FR2007/001370 patent/WO2008020129A1/fr active Application Filing
  • 2007-08-14 EP EP07823422A patent/EP2066444A1/fr not_active Withdrawn
  • 2007-08-14 MY MYPI20090595A patent/MY154950A/en unknown
  • 2007-08-14 AU AU2007285664A patent/AU2007285664B2/en not_active Ceased
  • 2007-08-14 US US12/377,928 patent/US20110305610A1/en not_active Abandoned
  • 2007-08-14 CN CN2007800306496A patent/CN101522307B/zh not_active Expired - Fee Related
• 2009
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