DE10020555A1 - Method and device for cleaning exhaust gases from an internal combustion engine - Google Patents

Method and device for cleaning exhaust gases from an internal combustion engine

Info

Publication number
DE10020555A1
DE10020555A1 DE2000120555 DE10020555A DE10020555A1 DE 10020555 A1 DE10020555 A1 DE 10020555A1 DE 2000120555 DE2000120555 DE 2000120555 DE 10020555 A DE10020555 A DE 10020555A DE 10020555 A1 DE10020555 A1 DE 10020555A1
Authority
DE
Germany
Prior art keywords
exhaust gas
catalyst
means
characterized
particular
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.)
Withdrawn
Application number
DE2000120555
Other languages
German (de)
Inventor
Bernd Mahr
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.)
Robert Bosch GmbH
Original Assignee
Robert Bosch GmbH
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 Robert Bosch GmbH filed Critical Robert Bosch GmbH
Priority to DE2000120555 priority Critical patent/DE10020555A1/en
Publication of DE10020555A1 publication Critical patent/DE10020555A1/en
Withdrawn legal-status Critical Current

Links

Classifications

    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01NGAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N3/00Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
    • F01N3/08Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous
    • F01N3/10Exhaust 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
    • F01N3/18Exhaust 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
    • F01N3/20Exhaust 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
    • F01N3/2066Selective catalytic reduction [SCR]
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01DSEPARATION
    • B01D53/00Separation 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
    • B01D53/34Chemical or biological purification of waste gases
    • B01D53/92Chemical or biological purification of waste gases of engine exhaust gases
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01DSEPARATION
    • B01D53/00Separation 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
    • B01D53/34Chemical or biological purification of waste gases
    • B01D53/92Chemical or biological purification of waste gases of engine exhaust gases
    • B01D53/94Chemical or biological purification of waste gases of engine exhaust gases by catalytic processes
    • B01D53/9404Removing only nitrogen compounds
    • B01D53/9409Nitrogen oxides
    • B01D53/9431Processes characterised by a specific device
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01DSEPARATION
    • B01D53/00Separation 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
    • B01D53/34Chemical or biological purification of waste gases
    • B01D53/92Chemical or biological purification of waste gases of engine exhaust gases
    • B01D53/94Chemical or biological purification of waste gases of engine exhaust gases by catalytic processes
    • B01D53/9445Simultaneously removing carbon monoxide, hydrocarbons or nitrogen oxides making use of three-way catalysts [TWC] or four-way-catalysts [FWC]
    • B01D53/9454Simultaneously removing carbon monoxide, hydrocarbons or nitrogen oxides making use of three-way catalysts [TWC] or four-way-catalysts [FWC] characterised by a specific device
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01NGAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N13/00Exhaust or silencing apparatus characterised by constructional features ; Exhaust or silencing apparatus, or parts thereof, having pertinent characteristics not provided for in, or of interest apart from, groups F01N1/00 - F01N5/00, F01N9/00, F01N11/00
    • F01N13/009Exhaust or silencing apparatus characterised by constructional features ; Exhaust or silencing apparatus, or parts thereof, having pertinent characteristics not provided for in, or of interest apart from, groups F01N1/00 - F01N5/00, F01N9/00, F01N11/00 having two or more separate purifying devices arranged in series
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01NGAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N13/00Exhaust or silencing apparatus characterised by constructional features ; Exhaust or silencing apparatus, or parts thereof, having pertinent characteristics not provided for in, or of interest apart from, groups F01N1/00 - F01N5/00, F01N9/00, F01N11/00
    • F01N13/009Exhaust or silencing apparatus characterised by constructional features ; Exhaust or silencing apparatus, or parts thereof, having pertinent characteristics not provided for in, or of interest apart from, groups F01N1/00 - F01N5/00, F01N9/00, F01N11/00 having two or more separate purifying devices arranged in series
    • F01N13/0093Exhaust or silencing apparatus characterised by constructional features ; Exhaust or silencing apparatus, or parts thereof, having pertinent characteristics not provided for in, or of interest apart from, groups F01N1/00 - F01N5/00, F01N9/00, F01N11/00 having two or more separate purifying devices arranged in series the purifying devices are of the same type
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01NGAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N3/00Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
    • F01N3/01Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust by means of electric or electrostatic separators
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01NGAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N3/00Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
    • F01N3/02Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust
    • F01N3/021Exhaust 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
    • F01N3/023Exhaust 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 using means for regenerating the filters, e.g. by burning trapped particles
    • F01N3/0231Exhaust 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 using means for regenerating the filters, e.g. by burning trapped particles using special exhaust apparatus upstream of the filter for producing nitrogen dioxide, e.g. for continuous filter regeneration systems [CRT]
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01NGAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N3/00Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
    • F01N3/02Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust
    • F01N3/021Exhaust 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
    • F01N3/033Exhaust 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 in combination with other devices
    • F01N3/035Exhaust 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 in combination with other devices with catalytic reactors, e.g. catalysed diesel particulate filters
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01NGAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N3/00Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
    • F01N3/08Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous
    • F01N3/0807Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by using absorbents or adsorbents
    • F01N3/0828Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by using absorbents or adsorbents characterised by the absorbed or adsorbed substances
    • F01N3/0842Nitrogen oxides
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01NGAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N3/00Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
    • F01N3/08Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous
    • F01N3/0892Electric or magnetic treatment, e.g. dissociation of noxious components
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01NGAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N3/00Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
    • F01N3/08Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous
    • F01N3/10Exhaust 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
    • F01N3/24Exhaust 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 constructional aspects of converting apparatus
    • F01N3/28Construction of catalytic reactors
    • F01N3/2882Catalytic reactors combined or associated with other devices, e.g. exhaust silencers or other exhaust purification devices
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01DSEPARATION
    • B01D2259/00Type of treatment
    • B01D2259/80Employing electric, magnetic, electromagnetic or wave energy, or particle radiation
    • B01D2259/818Employing electrical discharges or the generation of a plasma
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01DSEPARATION
    • B01D53/00Separation 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
    • B01D53/32Separation 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 by electrical effects other than those provided for in group B01D61/00
    • B01D53/323Separation 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 by electrical effects other than those provided for in group B01D61/00 by electrostatic effects or by high-voltage electric fields
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01NGAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N2240/00Combination or association of two or more different exhaust treating devices, or of at least one such device with an auxiliary device, not covered by indexing codes F01N2230/00 or F01N2250/00, one of the devices being
    • F01N2240/04Combination or association of two or more different exhaust treating devices, or of at least one such device with an auxiliary device, not covered by indexing codes F01N2230/00 or F01N2250/00, one of the devices being an electric, e.g. electrostatic, device other than a heater
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01NGAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N2240/00Combination or association of two or more different exhaust treating devices, or of at least one such device with an auxiliary device, not covered by indexing codes F01N2230/00 or F01N2250/00, one of the devices being
    • F01N2240/28Combination or association of two or more different exhaust treating devices, or of at least one such device with an auxiliary device, not covered by indexing codes F01N2230/00 or F01N2250/00, one of the devices being a plasma reactor
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01NGAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N2240/00Combination or association of two or more different exhaust treating devices, or of at least one such device with an auxiliary device, not covered by indexing codes F01N2230/00 or F01N2250/00, one of the devices being
    • F01N2240/40Combination or association of two or more different exhaust treating devices, or of at least one such device with an auxiliary device, not covered by indexing codes F01N2230/00 or F01N2250/00, one of the devices being a hydrolysis catalyst
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01NGAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N2260/00Exhaust treating devices having provisions not otherwise provided for
    • F01N2260/04Exhaust treating devices having provisions not otherwise provided for for regeneration or reactivation, e.g. of catalyst
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01NGAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N2610/00Adding substances to exhaust gases
    • F01N2610/02Adding substances to exhaust gases the substance being ammonia or urea
    • YGENERAL 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
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02TCLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T10/00Road transport of goods or passengers
    • Y02T10/10Internal combustion engine [ICE] based vehicles
    • Y02T10/20Exhaust after-treatment
    • Y02T10/22Three way catalyst technology, i.e. oxidation or reduction at stoichiometric equivalence ratio
    • YGENERAL 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
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02TCLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T10/00Road transport of goods or passengers
    • Y02T10/10Internal combustion engine [ICE] based vehicles
    • Y02T10/20Exhaust after-treatment
    • Y02T10/24Selective Catalytic Reactors for reduction in oxygen rich atmosphere

Abstract

Process for cleaning exhaust gases of an internal combustion engine with the following steps: DOLLAR A - introduction of the exhaust gas comprising gaseous and particulate pollutants into an oxidation catalyst and / or a plasma reactor for at least partial oxidation of the gaseous pollutants contained in the exhaust gas, in particular in accordance with the reactions NO-> NO¶ 2¶, CO-> CO¶2¶, HC-> CO¶2¶, DOLLAR A - electrical loading of the exhaust gas for electrical charging or polarization of particulate pollutants, DOLLAR A - separation of the electrically charged or polarized particulate pollutants on one with respect to the charge or polarization of the opposite electrical pole or to the ground of a separating device, in particular a second catalytic converter, and DOLLAR A - combustion of the soot particles thus separated by means of the NO2 in the exhaust gas.

Description

The present invention relates to a method and a Device for cleaning exhaust gases Internal combustion engine.

In recent years, there has been a tightening of the legal limit values for car emissions worldwide, which is partly accompanied by efforts to reduce CO 2 emissions. As a result, lean-burning, direct-injection engines are becoming increasingly important, but due to the excess of oxygen, exhaust gas cleaning still causes problems with regard to nitrogen oxides (NO x consisting of NO and NO 2 ). One solution for diesel cars is the selective catalytic reduction (SCR) of nitrogen oxides using suitable catalysts. Another option for nitrogen oxide reduction is the NO x storage catalytic converter.

With efficient combustion, diesel engines have very low HC concentrations (HC - Hydro Carbons) in the exhaust gas. Here, reducing agents are suitable that release ammonia, for example urea or urea-water solution, or ammonia itself. These reducing agents can reduce nitrogen oxides to more than 80% using suitable catalysts even with substoichiometric metering. With ammonia (NH 3 ) as a reducing agent, this technology has been used successfully in power plants for nitrogen oxide reduction for many years. Solid or liquid substances are better suited for mobile use. In contrast to ammonia, they are harmless per se, but allow the generation of the ammonia required for the catalytic reaction on board a motor vehicle. An example of such a substance is urea, from which ammonia can be obtained by thermal decomposition. The hydrolysis of urea, which is added to the exhaust gas, for example in the form of an aqueous solution, can be carried out on the same catalyst as the selective catalytic reduction.

In passenger cars in particular, there is no Catalyst and reducing agent the problem that the Exhaust gas temperatures in the starting phase and during city trips with frequent idle phases for selective catalytic Reduction is not enough. In this context it is difficult to meet future limits.

An energetically complex way to solve this Problems exist in the use of heated catalysts. It is also known exhaust gases with non-thermal plasmas  to treat in combination with catalysts, thus for to achieve an effective exhaust gas cleaning Temperature ranges in catalysts below 100 ° C can be reduced.

Non-thermal plasmas are known to be in them by electron impact dissociation of the main components of an exhaust gas energetically efficient chemically active Radicals are generated that are in low Attack concentrations of existing pollutants. Examples of non-thermal plasmas are pulsed Corona discharges as well as the dielectric barrier Discharges (DBE). When operated lean Internal combustion engines, such as the diesel engine, N, O and OH radicals are expected, both trigger reducing and oxidizing reactions.

In addition to the gaseous pollutants in an exhaust gas, in particular carbon monoxide (CO), hydrocarbons (HC), nitrogen oxides (NO x ) and sulfur dioxide (SO 2 ), special attention should be paid to solid pollutants, in particular soot particles. Soot particles are formed during combustion with a lack of air, which is the case locally, for example in the case of a diesel engine due to the inhomogeneous mixture. The sharp increase in soot when approaching λ = 1 follows from the increasing expansion of the rich mixture zones as a result of an increased injection quantity. Due to the soot particle emissions, essentially carbon particles, the diesel engine repeatedly comes into public criticism. The particles consist of solid, soluble and volatile components which, due to their diameter of only a few ten thousandths of a millimeter, are suspended in the air.

To remove the solid particles in the exhaust gas from Diesel engines are known as soot filters. It will be here various filter systems used, according to State of the art a so-called ceramic monolith filter currently the best compromise on the filter represents requirements. In contrast to continuous catalyst monoliths are the channels for that Soot filter mutually closed, so that particle-laden exhaust gas due to the uncoated, porous Walls of the honeycomb body must flow. Store the particles themselves in the pores. Depending on the porosity of the ceramic body The efficiency of the filter fluctuates between 70 and 90%.

Combined systems with catalysts and particle filters are also known. Here, for example, the CRT system (Continuously Regenerating Trap) is pointed out, which has an oxidation catalyst, in particular for carrying out a main reaction according to NO + 1 / 2O 2 → NO 2 and a downstream particle filter, in which a reaction of the form C + 2NO 2 → CO 2 + 2NO is feasible.

As a disadvantage with particle filters or combined Systems made of particle filters and catalysts have been proven the high resulting in such systems Exhaust back pressure. It should also be noted that after approx. 80,000 km mileage of a car an expansion of the Particulate filter for cleaning oil ash is necessary. In the case of CRT systems, it should also be pointed out that the  mentioned reaction taking place in the particle filter encountered difficulties when the soot or Carbon particles only poorly on the particle filter be liable.

To ensure the full functionality of the filter they have to be regenerated at certain intervals. There are two methods for cleaning, in in both cases soot particles are burned: in the chemical Processes add additives to the fuel's ignitability the soot particles down to the usual exhaust gas temperature. The additions can be disadvantageous secondary emissions. At the thermal process becomes a fuel assembly switched on, which the exhaust gas temperature to about 700 ° C. elevated. For this, burner elements with high performance needed. The regeneration can be done in the simplest case Carry out with the engine switched off. The time of Filter regeneration is either via a time control or determined via a pressure cell. Especially that Providing a soot filter in combination with a Fuel element proves to be relatively expensive in practice and large building, so that searched for further possibilities will be able to do without such measures.

The object of the invention is therefore to provide a Process or an apparatus for cleaning exhaust gases of an internal combustion engine with which in as simple as possible Wise efficient cleaning possible is.  

This problem is solved by a cleaning process of exhaust gases from an internal combustion engine with the characteristics of Claim 1 and a corresponding device with the features of claim 4.

According to the invention is a compact exhaust gas treatment system provided which high pollutant Conversion rates realized. To be particularly advantageous proves that when using the invention Measures compared to traditional approaches only low exhaust back pressures arise.

The system according to the invention is robust and has proven itself for Diesel engines and gasoline engines are equally suitable. At least on a complex particle filter system partially, can be dispensed with, in particular there is no burner necessary for the regeneration of a particle filter. The System according to the invention is further characterized in that that it is not susceptible to oil ash, which is the case with conventional systems is a practical problem.

The first electric field provided according to the invention can in the simplest case, be designed as a capacitor. It is also conceivable with the oxidation catalyst appropriate means for generating the electrical Field. Here, for example, it is possible an integrated oxidation catalyst / plasma reactor to provide. It is also possible according to the invention to dispense with an oxidation catalyst and the system only on the input side with a plasma reactor. On such a plasma reactor is on the one hand with appropriate Temperatures capable of oxidation  To support exhaust gas components and on the other hand the Charging or polarization provided according to the invention to ensure the particulate pollutants.

The electrical supply is expediently carried out the exhaust gas by means of a first electric field, which in particular in the form of a plasma reactor after Principle of barrier discharge or according to the dielectric disabled discharge works or in the form of suitable Capacitor means is realized.

The electrical opposite pole or ground pole of the second electrical field can be used, for example, as a ceramic Monolith or in the form of bulk material, metal foam, Ceramic foam or be implemented as a metal carrier. At suitable catalytic coating is an integration the opposite pole or ground pole with a second catalyst realizable.

The first and the second electric field can be used as DC or AC voltage source (or plasma or corona discharge).

Advantageous embodiments of the invention Procedures are the subject of the subclaims.

Expediently, NO, which is the combustion of the Soot particles are formed or contained in the original exhaust gas was, by means of a downstream Denitrification catalyst reduced. With this measure is a further purification of the exhaust gas from pollutants  achievable. It is possible to use the denitrification catalyst and to train the second catalyst integrated.

It is preferred that the exhaust gas is subjected to a reducing agent, in particular urea or a urea-water solution, before and / or after its introduction into the first electric field / plasma. Particle growth can be supported by this measure, which promotes the deposition of the particles on the electrical opposite pole and / or the mass of the second electrical field and thus facilitates the oxidation of the particles. It should be mentioned that H 2 or O 3 can also be used as reducing agents:

The expediently point to the second electrical field assigned or downstream catalyst means Hydrolysis catalyst and / or one Denitrification catalyst, especially an SCR Catalyst, and / or an oxidation catalyst. By means of such catalysts, which if necessary as Unity can be formed is another effective Exhaust gas cleaning achievable. It should be noted that if necessary to individual of the above Catalyst components can be dispensed with.

According to a further preferred embodiment, the device according to the invention also has at least one NO x sensor and / or at least one particle sensor and / or a temperature sensor. Such sensors can be provided in particular before and after the exhaust gas aftertreatment system in order to check or control the effectiveness of the system.

Preferred embodiments of the invention will now further explained with reference to the accompanying drawing. In this shows, each schematically

Fig. 1 of a block diagram a first preferred embodiment of the device according to the invention,

Fig. 2 block diagram-like a second preferred embodiment of the device according to the invention, and

Fig. 3 block diagram-like a third preferred embodiment of the device according to the invention.

The exhaust gas purification system shown in FIG. 1 initially has an oxidation catalytic converter 1 . The oxidation catalytic converter 1 serves to oxidize the gaseous pollutants contained in an internal combustion engine exhaust gas, in particular carbon monoxide, hydrocarbons and nitrogen oxides, for example in accordance with the reaction equations CO → CO 2 , HC → CO 2 and NO → NO 2 . It should be noted that a plasma reactor can be provided instead of or in addition to the oxidation catalyst 1 .

The exhaust gas emerging from the oxidation catalytic converter 1 , which is at least partially oxidized as described, is then introduced into a first electrical field 2 . The electric field 2 serves for the electrical charging or polarization of soot particles (carbon particles) also contained in the exhaust gas. The first electrical field 1 can be implemented in any suitable manner, in the simplest case as a capacitor. It can also be made in one piece or integrated with the oxidation catalyst 1 and / or a plasma reactor. In particular, the plasma reactor can be used to generate the first electrical field.

The particles charged by means of the first electrical field 2 are now introduced into the effective range of a second electrical field 3, which represents an electrical opposite pole to the charging of the particles. This second electrical field 3 or the electrical opposite pole can be located before the entry, directly at the entry or in a first section of a subsequent further catalyst 4 . It is also possible to provide the electric field in connection with a non-catalytic separating device, whereby an effective particle filter can be implemented even without a catalytic effect.

The charged soot particles differ due to a electrostatic interaction on the electrical Opposite pole. It should be noted once again that a Deposition to mass is advantageously possible.

The soot particles adhering to the catalyst 4 (by means of impactation) are now easier to burn by means of the NO or NO 2 also present in the exhaust gas or generated in the first oxidation catalyst 1 , precisely because of their electrostatically assisted adhesion, than is the case with solutions according to the State of the art was possible.

The NO produced during this combustion, as well as the NO not oxidized in the first catalytic converter 1 , is reduced in a subsequent denitrification catalytic converter 5 (DeNOx catalytic converter). The SCR catalytic converter (Selective Catalytic Reduction) or the NO x storage catalytic converter may be mentioned as an example of a DeNOx catalytic converter suitable in this context.

It should be noted that even without the provision of the second electric field 3, a much better adhesion of the soot particles to the second catalytic converter 4 should be observed compared to conventional solutions, since this catalytic converter is usually in contact with the vehicle mass.

It should also be pointed out that the second catalytic converter 4 and the denitrification catalytic converter 5 can optionally be designed as a unit.

A further preferred embodiment of the system according to the invention is explained with reference to FIG. 2.

1 again describes an oxidation catalyst (or a plasma reactor). By means of a urea metering device 6 , it is possible to meter urea or a urea-water solution into the exhaust gas before or after the first electrical field 2 . In this case, urea or urea-water solution acts as a reducing agent and also supports growth of the soot particles, which supports the deposition of the particles on the electrical opposite pole of the catalyst 4 . As further shown in FIG. 2, a hydrolysis catalytic converter 7 and a further oxidation catalytic converter 8 can be connected downstream of the second catalytic converter in addition to the SCR catalytic converter 5 already described with reference to FIG. 1. The catalyst 4 , in particular the second electric field 3 , the hydrolysis catalyst 7 , the SCR catalyst 5 and the oxidation catalyst 8 can optionally be combined into one unit, it also being possible to combine the second catalyst 4 and the hydrolysis catalyst 7 into a first, and to combine the SCR catalytic converter 5 and the oxidation catalytic converter 8 into a second unit.

The embodiment according to FIG. 3 differs from that of FIG. 2 in that a hydrolysis catalytic converter 7 is dispensed with. It is also conceivable to dispense with the oxidation catalytic converter 8 .

The SCR catalytic converter, which is preferably used as a denitrification catalytic converter 5, is expediently designed with a further urea metering system (not shown). The catalysts mentioned can be catalysts based on metal or ceramic (metal support, ceramic monoliths, bulk material, metal foam, ceramic foam).

Following the systems shown in each case, NO x , HC and / or NH 3 sensors and an exhaust gas temperature sensor are preferably also provided. Furthermore, a temperature measuring point before or after the first oxidation catalyst 1 (or plasma reactor) has proven to be advantageous. In addition, a NO x sensor can be used in front of the exhaust gas aftertreatment system. It should also be pointed out that particle sensors can also be provided before or after the exhaust gas aftertreatment system or between its individual components.

Finally, it should be noted that, for example, the embodiment according to FIG. 1 can also be used as a particle filter without the provision of the denitrification catalyst 5 , ie only with the oxidation catalyst 1 , the electric field 2 and the second catalyst 4 .

Claims (8)

1. A method for cleaning exhaust gases from an internal combustion engine with the following steps:
  • - Introduction of the gaseous and particulate pollutants exhaust gas in an oxidation catalyst and / or a plasma reactor for at least partial oxidation of the gaseous pollutants contained in the exhaust gas, in particular accordingly the reactions NO → NO2, CO → CO 2 , HC → CO 2 .
  • - electrical loading of the exhaust gas for electrical charging or polarization of particulate pollutants,
  • - Deposition of the electrically charged or polarized particulate pollutants on an opposite electrical pole with respect to the charging or polarization or on the mass of a separation device, in particular a ceramic foam, metal foam or bulk material, in particular a second catalyst, and
  • - Combustion of the soot particles separated in this way by means of the NO 2 present in the exhaust gas.
2. The method according to claim 1, characterized in that the electrical loading of the exhaust gas by means of a  First electrical field takes place, which in particular in Form of a plasma reactor based on the principle of Barrier discharge or after the dielectric barrier Discharge works or in the form of suitable Capacitor means realized.
3. The method according to any one of claims 1 or 2, characterized in that NO produced during the combustion of particulate pollutants is reduced by means of a downstream denitrification catalyst ( 5 ).
4. The method according to any one of claims 1 to 3, characterized characterized in that the exhaust gas before and / or after it Introduction into the first electric field with a Reducing agents, especially urea or one Urea water solution or hydrogen or oxygen, is applied.
5. Device for cleaning exhaust gases from an internal combustion engine, with
an oxidation catalyst ( 1 ) and / or a plasma reactor for at least partial oxidation of gaseous pollutants contained in the exhaust gas,
Means ( 2 ) for generating a first electric field in which particulate pollutants contained in the exhaust gas can be electrically charged or polarized, and
Means ( 3 ) for generating a second electric field, which are designed such that the electrically charged or polarized particulate pollutants are deposited on an opposite pole with respect to charging or polarization or on the mass of a separating device, in particular a second catalyst ( 4 ) are, so that combustion of the separated particulate pollutants can be carried out by means of the NO 2 contained in the exhaust gas.
6. The device according to claim 5, characterized by Means for loading the exhaust gas with a Reducing agents, especially urea or urea Water solution, before and / or after its application by means of the first electric field.
7. Device according to one of claims 5 or 6, characterized characterized in that the second catalyst Hydrolysis catalyst and / or one Denitrification catalyst, especially an SCR Has catalyst, and / or an oxidation catalyst.
8. Device according to one of claims 5 to 7, characterized by at least one NO x sensor and / or at least one particle sensor and / or at least one temperature sensor.
DE2000120555 2000-04-27 2000-04-27 Method and device for cleaning exhaust gases from an internal combustion engine Withdrawn DE10020555A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
DE2000120555 DE10020555A1 (en) 2000-04-27 2000-04-27 Method and device for cleaning exhaust gases from an internal combustion engine

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE2000120555 DE10020555A1 (en) 2000-04-27 2000-04-27 Method and device for cleaning exhaust gases from an internal combustion engine
PCT/DE2001/001261 WO2001080977A1 (en) 2000-04-27 2001-04-03 Method and device for purifying the exhaust gases of an internal combustion engine

Publications (1)

Publication Number Publication Date
DE10020555A1 true DE10020555A1 (en) 2001-10-31

Family

ID=7640055

Family Applications (1)

Application Number Title Priority Date Filing Date
DE2000120555 Withdrawn DE10020555A1 (en) 2000-04-27 2000-04-27 Method and device for cleaning exhaust gases from an internal combustion engine

Country Status (2)

Country Link
DE (1) DE10020555A1 (en)
WO (1) WO2001080977A1 (en)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2004025092A1 (en) * 2002-09-05 2004-03-25 Robert Bosch Gmbh Exhaust gas post-treatment arrangement and method therefor
EP1515012A1 (en) * 2003-09-11 2005-03-16 PS Unternehmensbeteiligungs GmbH Device for elimination of carbon black particulates from an exhaust gas stream of an internal combustion engine
BE1016015A5 (en) * 2004-05-11 2006-01-10 Mann Naturenergie Gmbh & Co Kg Installation of treatment of exhaust gases for combustion engines and method for cleaning exhaust gases.
WO2006128712A1 (en) * 2005-06-03 2006-12-07 Emitec Gesellschaft Für Emissionstechnologie Mbh Method and device for treating exhaust gases of internal combusting engines
DE102008062417A1 (en) 2008-12-17 2010-07-01 Volkswagen Ag Exhaust gas cleaning system for cleaning exhaust gas flow of internal combustion engine, has exhaust gas turbine driven by exhaust gas flow
DE102010060966B3 (en) * 2010-12-02 2012-04-19 Reinhausen Plasma Gmbh A generator

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2003054364A2 (en) * 2001-12-20 2003-07-03 Johnson Matthey Public Limited Company Method and apparatus for filtering partriculate matter and selective catalytic reduction of nox
FR2918708A1 (en) * 2007-07-09 2009-01-16 Renault Sas Evaluation of loading a particle filter.
DE102009037050A1 (en) * 2009-08-13 2011-02-17 Polysius Ag Method and device for preventing dust deposits in a treatment device through which a dust-laden exhaust gas flows

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB9301433D0 (en) * 1993-01-20 1993-03-17 Atomic Energy Authority Uk Gas purification
US6038854A (en) * 1996-08-19 2000-03-21 The Regents Of The University Of California Plasma regenerated particulate trap and NOx reduction system
DE19635231A1 (en) * 1996-08-30 1998-03-05 Siemens Ag Diesel exhaust gas purification unit combining high-frequency silent plasma discharge and catalytic action
DE19826831A1 (en) * 1998-04-09 1999-10-14 Fev Motorentech Gmbh Reduction of noxious petrol and diesel engine exhaust gas emissions
GB9821947D0 (en) * 1998-10-09 1998-12-02 Johnson Matthey Plc Purification of exhaust gases
AU6111799A (en) * 1998-10-12 2000-05-01 Johnson Matthey Public Limited Company Process and apparatus for treating combustion exhaust gas

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2004025092A1 (en) * 2002-09-05 2004-03-25 Robert Bosch Gmbh Exhaust gas post-treatment arrangement and method therefor
EP1515012A1 (en) * 2003-09-11 2005-03-16 PS Unternehmensbeteiligungs GmbH Device for elimination of carbon black particulates from an exhaust gas stream of an internal combustion engine
EP1734234A3 (en) * 2003-09-11 2007-01-03 Pankl Emission Control Systems GmbH Device for elimination of carbon black particulates from an exhaust gas stream of an internal combustion engine
BE1016015A5 (en) * 2004-05-11 2006-01-10 Mann Naturenergie Gmbh & Co Kg Installation of treatment of exhaust gases for combustion engines and method for cleaning exhaust gases.
WO2006128712A1 (en) * 2005-06-03 2006-12-07 Emitec Gesellschaft Für Emissionstechnologie Mbh Method and device for treating exhaust gases of internal combusting engines
DE102008062417A1 (en) 2008-12-17 2010-07-01 Volkswagen Ag Exhaust gas cleaning system for cleaning exhaust gas flow of internal combustion engine, has exhaust gas turbine driven by exhaust gas flow
DE102010060966B3 (en) * 2010-12-02 2012-04-19 Reinhausen Plasma Gmbh A generator
WO2012072298A1 (en) 2010-12-02 2012-06-07 Reinhausen Plasma Gmbh Plasma generator

Also Published As

Publication number Publication date
WO2001080977A1 (en) 2001-11-01

Similar Documents

Publication Publication Date Title
US20170080388A1 (en) Gasoline engine with an exhaust system for combusting particulate matter
JP5876727B2 (en) Filter for collecting particulate matter from exhaust gas discharged from compression ignition engines
DE102010023819B4 (en) Exhaust gas treatment system for a diesel engine Method of using it and diesel engine and exhaust gas treatment system
KR101699923B1 (en) Method for purification of exhaust gas from a diesel engine
US8661790B2 (en) Electronically heated NOx adsorber catalyst
US8555617B2 (en) Exhaust gas treatment system including a four-way catalyst and urea SCR catalyst and method of using the same
EP1336032B1 (en) Method for reducing particle emissions containing carbon of diesel motors and a corresponding system
Farrauto et al. Catalytic converters: state of the art and perspectives
DE602004003354T2 (en) A particle filter and nox-absorber exhaust system for internal combustion engine with lubricants
KR100981338B1 (en) Exhaust cleaner for internal combustion engine
KR100496765B1 (en) Method and device for eliminating oxide pollutants in an exhaust gas containing oxygen and engine operating thereby
US8453430B2 (en) Configuration and method for cleaning an exhaust gas flow of an internal combustion engine by separating particles and motor vehicle having the configuration
EP1128895B1 (en) Process and apparatus for treating combustion exhaust gas
DE10315593B4 (en) Exhaust gas aftertreatment device and method
Alkemade et al. Engines and exhaust after treatment systems for future automotive applications
US6732507B1 (en) NOx aftertreatment system and method for internal combustion engines
EP1961933B1 (en) Catalytically activated diesel particulate filter with ammoniac blocking action
US7510600B2 (en) Gas purifying apparatus
Johnson Diesel emissions in review
US6696031B1 (en) Treatment of exhaust gas
US8505279B2 (en) Exhaust gas treatment system including a four-way catalyst and urea SCR catalyst and method of using the same
KR101659788B1 (en) Denox of diesel engine exhaust gases using a temperature-controlled precatalyst for providing no2 in accordance with the requirements
DE69902446T3 (en) Improvements of the pollution
US6029442A (en) Method and apparatus for using free radicals to reduce pollutants in the exhaust gases from the combustion of fuel
JP5630024B2 (en) Diesel engine exhaust purification device and exhaust purification method

Legal Events

Date Code Title Description
8139 Disposal/non-payment of the annual fee