WO2006041273A1 - Procede de fabrication d'un element catalytique multifonctions - Google Patents

Procede de fabrication d'un element catalytique multifonctions Download PDF

Info

Publication number
WO2006041273A1
WO2006041273A1 PCT/LT2004/000006 LT2004000006W WO2006041273A1 WO 2006041273 A1 WO2006041273 A1 WO 2006041273A1 LT 2004000006 W LT2004000006 W LT 2004000006W WO 2006041273 A1 WO2006041273 A1 WO 2006041273A1
Authority
WO
WIPO (PCT)
Prior art keywords
catalyst
hydrotalcite
powder
catalytic
nitrogen oxides
Prior art date
Application number
PCT/LT2004/000006
Other languages
English (en)
Russian (ru)
Inventor
Alexander Pavlovich Khinsky
Rimantas Pakamanis
Original Assignee
Uab 'norta'
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 Uab 'norta' filed Critical Uab 'norta'
Priority to PCT/LT2004/000006 priority Critical patent/WO2006041273A1/fr
Publication of WO2006041273A1 publication Critical patent/WO2006041273A1/fr

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
    • F01N3/08—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous
    • F01N3/10—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust
    • F01N3/18—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust characterised by methods of operation; Control
    • F01N3/20—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust characterised by methods of operation; Control specially adapted for catalytic conversion ; Methods of operation or control of catalytic converters
    • F01N3/2006—Periodically heating or cooling catalytic reactors, e.g. at cold starting or overheating
    • F01N3/2013—Periodically heating or cooling catalytic reactors, e.g. at cold starting or overheating using electric or magnetic heating means
    • F01N3/2026—Periodically heating or cooling catalytic reactors, e.g. at cold starting or overheating using electric or magnetic heating means directly electrifying the catalyst substrate, i.e. heating the electrically conductive catalyst substrate by joule effect
    • 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
    • B01D2255/91—NOx-storage component incorporated in the catalyst
    • 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 invention relates to the field of mechanical engineering, and more particularly, to the field of automotive industry, and, in particular, to the field of designing devices for neutralizing exhaust gases of an internal combustion engine, namely carbon monoxide, hydrocarbons and nitrogen oxides.
  • the invention relates to the field of honeycomb structures, and, in particular, to the field of honeycomb structures heated by electric current.
  • the harmful components of the exhaust gases are mainly carbon monoxide, hydrocarbons and nitrogen oxides.
  • a specific feature of most catalytic devices is their lack of readiness for operation in the first seconds of engine operation. This is a consequence of the fact that even in the presence of a highly active catalyst, it takes time to warm it up to a temperature of at least 80-100 0 C. Until the catalyst is heated, the exhaust gases exit not neutralized. This situation is called the “cold” engine start.
  • catalytic converters are used using both ceramic and metal honeycomb carriers.
  • metal honeycomb carriers have a decisive advantage over ceramic ones because the thermal conductivity of a metal is two orders of magnitude higher than that of ceramic. Therefore, the use of ceramic honeycomb structures to ensure rapid heating of the catalyst in the conditions of a “cold” start is irrational.
  • the fastest heating of the metal honeycomb carrier under cold start conditions is ensured by both the use of individual design solutions and their combination. So, for example, a rather trivial design solution is to place the catalytic converter as close as possible to the place where the exhaust gases exit the engine. In this case, the exhaust gases leaving the engine do not have time to cool and provide the maximum temperature gradient, which, in turn, determines the most rapid heating of the cellular carrier and its normal functioning.
  • Another reserve for increasing the heating rate under conditions of a “cold” start is an increase in the cell density in the cross section of the honeycomb structure, which obviously increases the degree of heat transfer during the passage of the exhaust gas flow through the carrier and, thereby, increases the heating rate.
  • Catalytic elements and devices using a metal base with a catalyst deposited on its surface are widely described in the patent and technical literature.
  • a metal strip or a bulk porous metal structure obtained by a metallurgical or chemical method (sintering of powder materials, leaching, etc.) is used as a metal base.
  • a metal base is usually formed from it - a cylindrical (or ellipsoidal) element, and then a catalytic layer is applied to this element by immersion in a suspension, in several stages.
  • Another, more advanced method for producing catalytic elements is the method of spraying a suspension onto a pre-corrugated tape, followed by coagulation of the catalytic element.
  • the method of thermal spraying of ceramic materials provides reliable adhesion to a metal substrate, however, due to the melting of powder particles during the spraying process (gas flow temperature reaches 12000 0 C), the free surface of the coating is very low and is, as a rule, of the order of several m 2 per gram of coating.
  • the catalytic activity of the material is proportional to the size of the free surface, so that the effectiveness of catalytic coatings of this type is small.
  • the catalyst includes a metal carrier, an adhesive layer that improves the adhesion of the catalytic layer to the metal carrier, and the catalytic layer itself deposited on the adhesive layer, the catalytic layer being characterized by a smooth gradient of catalytically active components, which provides a 100% concentration of catalytically active components on the surface and is close to their concentration at the boundary of the adhesive and catalytic layers is zero.
  • the catalytic layer is applied by plasma spraying, and thermally easily decomposable substances such as hydroxides, nitrates and transition metal carbonates are included in the sprayed composition.
  • the spraying process provides the spraying of these materials without their thermal decomposition in the plasma jet.
  • Heat treatment in air in the temperature range 500 - 600 0 C provides activation of the catalyst.
  • Known German (DE59710895D), Austrian (AT252417T) and Korean patents (KR2000022062) which describes the method of production of a catalytic converter.
  • the sprayed material is applied by thermal spraying onto a carrier on which it is converted into a catalytically active composition during subsequent thermal activation.
  • US patents are also known (application US2001014648 and patent US6,228,801), which describes a method for producing a catalyst by thermal spraying a material containing titanium hydroxide onto a support, followed by converting the sprayed material into a catalyst by heat treatment.
  • the next, more advanced design solution is to change the design and manufacturing technology of the metal honeycomb carrier, ensuring its rapid heating in the conditions of a “cold” start.
  • fuel combustion can be used to heat the honeycomb carrier based on a steel strip, which is additionally supplied to the catalyst.
  • a metal type catalytic burner is described in US Pat. No. 6,334,769.
  • the burner includes channels that are coated with a catalyst, and channels that are not coated catalytically.
  • the ratio of the cross section of the channels with the catalyst to the channels without the catalyst is chosen large enough to support combustion without additional heat input, but not too large to avoid catalyst deactivation due to overheating during operation.
  • the temperature of the walls separating the channels will be at a level that ensures the catalytic combustion process without additional heating.
  • a metal-fired catalytic burner for high temperature conditions is described in US patents (US5,406,704 and US5,437,099).
  • the burner for the first stage of a multi-stage combustion process includes a honeycomb structure, where metal strips are coated with a catalyst on one side only. Tapes are additionally corrugated. Then the strips are bent so as to form a reactor with the necessary cross-section.
  • the reactor has rows of channels that are formed between the layers of the metal strip.
  • the tape coated on one side of the catalyst forms the walls of the channels in each other row.
  • a mixture of fuel and air which passes through channels coated with a catalyst, burns out.
  • a mixture of fuel with air which passes through channels not coated with a catalyst, does not burn out and cools the catalytic surfaces.
  • Corrugating in the “fish scale” type protects metal tapes from collapsing, and, in addition, forms a long, zigzag path for the gas flow to pass through.
  • a catalytic burner in a metal design with a lower ignition temperature is described in patent (AU1723401).
  • the burner is formed from corrugated metal strips completely coated with the catalyst on the one hand, while on the other hand only narrow bands at the edge of the tape are coated with the catalyst.
  • the tape is then bent so as to form a burner.
  • the burner has channels completely coated with the catalyst, which alternate with channels on which the catalyst is present only in the form of a narrow strip at the channel boundary. This alternation of coated and uncoated channels prevents overheating of the honeycomb structure and catalyst deactivation.
  • the application of the catalyst at the edge of an uncoated channel reduces the ignition temperature of the catalyst.
  • the metal catalytic reactor is described in European Patent (EP0724069).
  • the catalytic reactor is used to ignite the gas mixture in a multi-stage burner.
  • the catalytic reactor comprises a packet of corrugated metal tapes, each of which is coated with catalyst on one side, while the coated side of one tape is adjacent to the uncoated side of an adjacent tape.
  • the reactor has channels, in each of which there are two walls, and only one of them is covered with a catalyst.
  • the two strips have a spiral shape formed by winding two strips into a roll, each of the strips having a catalytic coating on only one side. The covered side of one of the strips faces facing the bare side of the other.
  • the spiral formed by winding two tapes into a roll includes channels containing a catalytic coating on only one wall of the channel.
  • a metal catalytic burner for a gas turbine is described in WO03068371.
  • a catalytic burner for a gas turbine includes a stack of metal strips, each of which has an end that serves as an input and an opposite end that serves as an output.
  • the inlet end of the tape on both sides has no catalytic coating in order to limit the temperature and maintain the rigidity of the tape at the output end.
  • both sides of the tape have “ignition” strips coated with a catalyst adjacent to the uncoated outlet strips.
  • One side of the tape (side A) also includes at least one strip “Burning”, while the other side (side B) does not have the corresponding strips with a supported catalyst.
  • the resulting structure prevents the burner from overheating, maintains its rigidity and reduces back pressure.
  • a metal-reforming catalytic reactor for steam reforming is described in U.S. Patent Application (US2004060238).
  • the compact reactor produces hydrogen to power a chemical current source, one that could be used in a car.
  • the reactor includes a first channel at least partially coated with a reforming catalyst and a second channel at least partially coated with a combustion catalyst, the channels being in thermal contact with each other.
  • the heat generated during fuel combustion is used in the steam reforming reaction.
  • the reactor can be equipped with a package of tapes forming channels for steam reforming, which alternate with channels for burning fuel.
  • the reactor may include a set of modules connected in series, and each module includes a tape package described above.
  • the design of the catalytic element to neutralize harmful gas impurities and the method of production of such an element are described in US patent (US5, 737,918).
  • the cylindrical catalyst element includes longitudinal channels with a catalyst inside these channels.
  • the longitudinal channels have a curved shape in cross section, and the thickness of the catalyst on the walls of the channels is constant.
  • the production method of the catalytic element is based on the production of a catalytically active layer based on alumina on the surface of a metal support by flame spraying.
  • a catalytically active layer based on alumina on the surface of a metal support by flame spraying.
  • the heating of the metal honeycomb structure as a whole or of its individual elements under conditions of a “cold” start can also be carried out by electric current.
  • the metal-heated honeycomb structure is described in US5,411,711.
  • the patent provides an example of a practical embodiment, in which a packet of metal tapes is formed in a cylindrical mandrel, bent in accordance with the letter S, to which an electric current is supplied through two contacts, in the form of half-shells placed at the ends of the honeycomb structure. Uniform distribution of electric current in a given honeycomb structure is achieved by regulating the size of the package of metal tapes and the shape of the contacts.
  • US Pat. No. 5,546,746 describes a combined catalytic element that provides both electric heating and ignition at the time of a “cold” start.
  • the element uses two types of structural components - components responsible for heating the element with electric current and components responsible for the "ignition" of the element.
  • Both of them are a composition of three thin metal ribbons connected in parallel, the central ribbon being corrugated and the two outermost ones flat. From these structural components, a bag is collected, which is then folded spirally to form a cylindrical element.
  • an insulating layer based on alumina is applied by immersion in a suspension. Then, on the components responsible for the ignition of the element at the time of the “cold” start, the catalysts are applied by impregnation.
  • the structural components of the catalytic element responsible for heating, while passing an electric current at the time of a “cold” start quickly heat up and give their heat to the structural components with a catalytic coating responsible for the “ignition” of the element, which ensures quick neutralization of harmful exhaust components.
  • US Pat. No. 5,628,928 discloses a catalytic element that includes metal-heated electric strips alternating with non-electric-heated thin metal tapes.
  • the set of ribbons described above coils spirally to form a catalytic element cylindrical shape.
  • An insulating coating based on alumina is applied to the surface of the tapes by precipitation from a suspension.
  • the heating of tapes not connected to the electric circuit is carried out due to thermal conductivity at the contact points of corrugated and flat tapes along the entire length of the catalytic element.
  • the catalytic element for “cold” start conditions in metal execution is described in the Russian patent (RU2126717).
  • the catalytic element is a honeycomb structure made of two metal tapes with a catalyst deposited by thermal spraying. One of the metal tapes is corrugated after spraying and coils with a flat tape, forming a honeycomb structure.
  • the thermal spraying method described in the invention provides an extremely high adhesion strength of the sprayed ceramic layer to the metal substrate, which allows mechanical processing (cutting, corrugation, perforation) of the tape immediately after spraying. High resistance to thermal cycling and gas erosion has also been reported.
  • Another technical solution that is being actively developed at present is the development of materials capable of sorbing some harmful components of exhaust gases on its surface and thereby preventing their emission, which is especially important in conditions of a “cold” start.
  • the proposed technical solution allows, according to its developers, to harmonize the operation of the catalytic converter, compensating for the difference in the adsorption rates of some harmful components of the exhaust gases, in particular, nitrogen oxides and the rate of oxidation of carbon monoxide.
  • the most interesting and promising solution in this area is the development of catalytically active materials that ensure the adsorption of nitrogen oxides with their subsequent reduction.
  • the catalysts they developed are based on the concept of the accumulation of NO in the form of nitrates on the surface of the catalyst with periodic recovery when the air / fuel ratio changes (due to a change in the operating mode of the engine or a special additive of hydrocarbons), which provides a change in work of the catalyst from oxidizing to reducing.
  • the reduction rate is two orders of magnitude higher than the adsorption rate and, as a result, the residence time of the catalyst under the conditions of an enriched mixture (excess fuel) is much shorter than the time of its residence under the conditions of a lean mixture (excess oxygen).
  • catalysts of this type materials obtained by decomposition of hydrotalcites of the Mg-Al system can be used. These catalysts have, as shown in studies, high catalytic activity, especially at low temperatures, and high resistance to poisoning by sulfur oxides.
  • honeycomb structure for the adsorption of nitrogen oxides and the oxidation of carbon monoxide and hydrocarbons in its various zones is a logical continuation of the sequence of design decisions in relation to the problem of neutralizing the harmful components of exhaust gases in the conditions of a “cold” start.
  • the honeycomb structure in metal with two different coatings is described in US Patent Application (US2003161766).
  • the honeycomb structure heated by electric current has at least two zones which are arranged sequentially in the direction of the gas flow and are used to clean the exhaust gases of the internal combustion engine.
  • a specific feature of this honeycomb structure is that at least two of its zones have different coatings. Different coatings have different functions, in particular during the “cold” phase of starting an internal combustion engine.
  • the function of the coating can be, for example, adsorption of gases, their catalytic conversion or oxidation of exhaust gas components.
  • the present invention proposes to separate these processes and conduct them in various areas of the honeycomb structure.
  • the first zone has a coating comprising an adsorbent material
  • the second zone has a catalytically active coating.
  • the honeycomb structure described above with two different coatings located in different zones of the honeycomb structure represents a significant step forward in the development of a catalytic converter capable of simultaneously performing various catalysis functions, such as adsorption, oxidation and recovery of harmful components of the exhaust gases of an internal combustion engine.
  • the so-called three-component catalyst has found wide application in the automotive industry, which can provide the simultaneous oxidation of carbon monoxide and hydrocarbons and the reduction of nitrogen oxides.
  • the conditions for the implementation of redox processes simultaneously and on the same catalyst impose severe restrictions on the ratio of redox components in the exhaust gas composition.
  • the so-called lambda probe is used, which ensures, by adjusting the engine parameters using the on-board computer, maintaining the fuel / air ratio within fairly narrow limits.
  • the transverse channel is a separate component of the honeycomb structure, performing both the functions of adsorption / reduction of nitrogen oxides and the function of oxidizing carbon monoxide and hydrocarbons, which is achieved by applying various types of catalysts on different walls of the channel. Structurally, this can be achieved by spraying various catalysts on two metal strips, which, after corrugating one of them, are folded into a honeycomb structure.
  • the subject of this invention is a catalytic element (block), which is a cylinder formed during the folding of two metal strips, one of which is deformed in such a way as to ensure the formation of protrusions on the surface, which play the role of spacers that provide the necessary amount of clearance when rolling.
  • a method of manufacturing a catalytic element is as follows. Various chemically active substances are applied to the tapes on both sides by thermal spraying in the following combination: on one tape - nitrogen oxide adsorbent / reduction catalyst, on the other - oxidation catalyst on one tape - nitrogen oxide adsorbent, on the other - reduction catalyst on one tape - adsorbent carbon monoxide and hydrocarbons, on the other - an oxidizing catalyst. Then the tape is subjected to mechanical processing (cold stamping, cutting, punching, crimping, etc.) to form merchandise structure when coagulating them into a catalytic block.
  • the catalytic block After the catalytic block is fully formed, it is subjected to thermal activation by annealing in air in the temperature range 400 - 800 0 C.
  • FIG. 3 radiographs of the coating in the process of thermal decomposition
  • FIG. 4 - x-ray thermal decomposition of the material
  • FIG. 5 structure of the test bench.
  • FIG 1 shows two steel strips after plasma spraying.
  • Plasma spraying was carried out on the equipment developed by the Hopta company, using an original design plasma torch.
  • a chemically active layer was applied to the tapes used to create the catalytic element on both sides, one of the tapes being coated with a nitrogen oxide adsorbent and a reducing catalyst, and the other with an oxidizing catalyst.
  • the tape After plasma spraying, the tape, on the surface of which an adsorbent / reduction catalyst was applied on both sides, was sanded on a special installation developed for this technological process.
  • the second tape on the surface of which an oxidizing catalyst was applied, was not corrugated. Then both tapes were twisted relative to the common transverse axis, as shown in fir.l. with the formation of the honeycomb structure of the catalytic element.
  • the catalytic element thus obtained is characterized in that two processes are localized in it, in each of its transverse channels.
  • the first - the adsorption of nitrogen oxides - is localized on the walls of the 1st channel formed by a corrugated tape
  • the second - the oxidation of carbon monoxide and hydrocarbons - is localized on the wall 2 of the channel formed by a flat ribbon.
  • nitrogen oxides are adsorbed from the exhaust gas stream, and carbon monoxide and hydrocarbons are oxidized to carbon dioxide and water vapor.
  • the catalytic element is heated by electric current to the desired temperature and the necessary amount of reducing gas is supplied into it (in each channel), which, for example, can be natural gas (methane), a reducing atmosphere is created, and nitrogen oxides are rapidly reduced to molecular nitrogen.
  • reducing gas for example, can be natural gas (methane)
  • the catalytic element for the neutralization of exhaust gases of an internal combustion engine was manufactured as follows.
  • the second tape was sprayed with a powder of the following composition: metallic aluminum 1%, aluminum hydroxide - 20%, a composite powder based on aluminum hydroxide coated with hydrotalcite of the Mg-Al-Co system - the rest.
  • the dispersion of the powder in both cases was 60-100 microns, the deposition was carried out by the plasma method.
  • the corrugation of the first tape was carried out, the corrugation had a triangular shape (in cross section), the height of the tooth was 2.5 - 3.0 mm.
  • each of the longitudinal channels in the block has two walls formed by a corrugated tape with an adsorbent / reduction catalyst deposited on their surface based on partially decomposed hydrotalcite of the Mg-Al-Cu system, and one wall formed by a flat tape, with deposited on its surface by an oxidizing catalyst based on cobalt oxide.
  • the thermal activation of the catalytic unit was carried out according to the regime: heating with a furnace to a temperature of 550 0 C, holding for 5 hours, heating with a furnace to a temperature of 650 0 C, holding for 3 hours and cooling with a furnace to normal temperature.
  • the tests were carried out on a bench using an internal combustion engine.
  • the engine cylinder capacity is 1.6 liters.
  • Thermocouple 3 and two blocks 4 with a diameter of 32 mm and a length of 100 mm were installed in a special cartridge 5 (Fig.
  • the content of harmful components of the exhaust gases at the inlet and outlet of the cartridge was monitored using a Tehnotest 488 instrument.
  • the control was carried out on the content of carbon monoxide, hydrocarbons and nitrogen oxides in the exhaust gases.
  • the total test time was 6 hours.
  • the catalytic blocks provide the removal of carbon monoxide completely, hydrocarbons by 90%, as well as 80% adsorption of nitrogen oxides. After heating with electric current and supplying an additional amount of fuel, nitrogen oxides are reduced to molecular nitrogen.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Combustion & Propulsion (AREA)
  • Health & Medical Sciences (AREA)
  • Mechanical Engineering (AREA)
  • Toxicology (AREA)
  • General Engineering & Computer Science (AREA)
  • Biomedical Technology (AREA)
  • Environmental & Geological Engineering (AREA)
  • Analytical Chemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Oil, Petroleum & Natural Gas (AREA)
  • Catalysts (AREA)

Abstract

L'invention appartient au domaine de l'industrie automobile et concerne notamment la conception de dispositifs destinés à neutraliser les gaz d'échappement des moteurs à combustion interne. Elle se rapporte au domaine des structures en alvéoles réchauffées par le courant électrique. Selon l'invention, un bloc catalytique est réalisé à partir de deux bandes métalliques; sur chacune d'elles, on applique par pulvérisation thermique un revêtement de substances chimiquement actives. Sur une bande on applique une substance absorbant les oxydes d'azote, et sur l'autre bande on applique un catalyseur d'oxydation des oxydes de carbone et des hydrocarbures. Une des bandes est soumise au gaufrage. Les deux bandes sont ensuite enroulées de manière à former des canaux ayant une section transversale triangulaire; deux côtés de chaque canal sont recouverts d'un absorbant et le troisième est recouvert d'un catalyseur d'oxydation (ou vice versa). Pendant la circulation des gaz d'échappement les oxydes d'azote sont sorbés sur des parois du canal, et l'oxyde de carbone ainsi que les hydrocarbures sont oxydés jusqu'au dioxyde de carbone et des vapeurs d'eau sur les autres parois. Lorsque la saturation de l'adsorbant par les oxydes d'azote est atteinte, le bloc catalytique est réchauffé par le courant électrique, et l'on y injecte de plus un gaz réducteur, ce qui assure la désorption et la réduction des oxydes d'azote.
PCT/LT2004/000006 2004-10-15 2004-10-15 Procede de fabrication d'un element catalytique multifonctions WO2006041273A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
PCT/LT2004/000006 WO2006041273A1 (fr) 2004-10-15 2004-10-15 Procede de fabrication d'un element catalytique multifonctions

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/LT2004/000006 WO2006041273A1 (fr) 2004-10-15 2004-10-15 Procede de fabrication d'un element catalytique multifonctions

Publications (1)

Publication Number Publication Date
WO2006041273A1 true WO2006041273A1 (fr) 2006-04-20

Family

ID=36148545

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/LT2004/000006 WO2006041273A1 (fr) 2004-10-15 2004-10-15 Procede de fabrication d'un element catalytique multifonctions

Country Status (1)

Country Link
WO (1) WO2006041273A1 (fr)

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
RU2126717C1 (ru) * 1995-03-06 1999-02-27 Хинский Александр Павлович Способ изготовления каталитического блока для нейтрализации газовых выбросов
RU2161068C2 (ru) * 1995-08-22 2000-12-27 Эмитек Гезельшафт Фюр Эмиссионстехнологи Мбх Способ изготовления сотового элемента из двух типов металлических листов, различающихся по своему строению
EP0820810B1 (fr) * 1993-12-28 2002-04-03 Ngk Insulators, Ltd. Purification de gaz d'échappement
US20030161766A1 (en) * 2000-10-18 2003-08-28 Brueck Rolf Heatable honeycomb body with two different coatings

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0820810B1 (fr) * 1993-12-28 2002-04-03 Ngk Insulators, Ltd. Purification de gaz d'échappement
RU2126717C1 (ru) * 1995-03-06 1999-02-27 Хинский Александр Павлович Способ изготовления каталитического блока для нейтрализации газовых выбросов
RU2161068C2 (ru) * 1995-08-22 2000-12-27 Эмитек Гезельшафт Фюр Эмиссионстехнологи Мбх Способ изготовления сотового элемента из двух типов металлических листов, различающихся по своему строению
US20030161766A1 (en) * 2000-10-18 2003-08-28 Brueck Rolf Heatable honeycomb body with two different coatings

Similar Documents

Publication Publication Date Title
EP1212135B1 (fr) Procede de preparation de matiere catalytique pour oxydation selective et elements catalyseurs contenant celle-ci
CA2077190C (fr) Procede catalytique
EP0967174B1 (fr) Dispositif de reformage
US7093428B2 (en) Exhaust system and method of thermal management
EP0913357B1 (fr) Dispositif de reformage et sa méthode de fonctionnement
EP0968958B1 (fr) Réacteur de reformage
US20060101809A1 (en) Internal combustion engine comprising a reducing agent production unit and operating method therefor
CA2124157A1 (fr) Convertisseur a corps partiellement chauffe a l'electricite
US7247258B2 (en) Compact partial oxidation reactor assemblage with fast start-up capability
US5456890A (en) Combined electrically heatable and light-off converter
KR20000068020A (ko) ＮＯｘ 흡착기
WO1993021431A1 (fr) Moyen de chauffage pour catalyseur
US5680503A (en) Honeycomb heater having a portion that is locally quickly heated
US20040216448A1 (en) Method of desulfation of nox-adsorbers
US4078898A (en) Catalyst-coated expanded metal foil substrate for an exhaust gas reactor
Twigg et al. Metal and coated-metal catalysts
US5308591A (en) Core body for catalytic converter
WO2006041273A1 (fr) Procede de fabrication d'un element catalytique multifonctions
JP3122919B2 (ja) 電気加熱触媒装置
US6447735B1 (en) Exhaust purifier and manufacturing method of same
WO1995008702A1 (fr) Piege a hydrocarbures combine avec un convertisseur a chauffage electrique
JP2000007304A (ja) 改質反応装置
JP3327164B2 (ja) 触媒体およびその製造方法
RU2796831C1 (ru) Способ нейтрализации токсичных компонентов дымовых газов без введения внешнего реагента
JP2002349248A (ja) ディーゼルエンジン排ガス中の窒素酸化物除去方法及び装置

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): AE AG AL AM AT AU AZ BA BB BG BR BW BY BZ CA CH CN CO CR CU CZ DE DK DM DZ EC EE EG ES FI GB GD GE GH GM HR HU ID IL IN IS JP KE KG KP KR KZ LC LK LR LS LT LU LV MA MD MG MK MN MW MX MZ NA NI NO NZ OM PG PH PL PT RO RU SC SD SE SG SK SL SY TJ TM TN TR TT TZ UA UG US UZ VC VN YU ZA ZM ZW

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): BW GH GM KE LS MW MZ NA SD SL SZ TZ UG ZM ZW AM AZ BY KG KZ MD RU TJ TM AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IT LU MC NL PL PT RO SE SI SK TR BF BJ CF CG CI CM GA GN GQ GW ML MR NE SN TD TG

121 Ep: the epo has been informed by wipo that ep was designated in this application
NENP Non-entry into the national phase

Ref country code: DE

WWE Wipo information: entry into national phase

Ref document number: 2004134336

Country of ref document: RU

122 Ep: pct application non-entry in european phase

Ref document number: 04793631

Country of ref document: EP

Kind code of ref document: A1