EP1885473A1

EP1885473A1 - Method and device for treating exhaust gases of internal combusting engines

Info

Publication number: EP1885473A1
Application number: EP06743101A
Authority: EP
Inventors: Rolf BRÜCK; Peter Hirth; Wolfgang Held; Eberhard Jacob; Ulf Klein
Original assignee: Emitec Gesellschaft fuer Emissionstechnologie mbH
Current assignee: Vitesco Technologies Lohmar Verwaltungs GmbH
Priority date: 2005-06-03
Filing date: 2006-06-02
Publication date: 2008-02-13
Also published as: RU2007147908A; JP2008542609A; KR20080017437A; US20080102010A1; WO2006128712A1; KR100918602B1

Abstract

The invention relates to an exhaust gas treating device comprising a particle separator (101), an SCR catalyst (102) for selectively reducing nitrogen oxides and an ammonia generator (103) for producing the ammonia in the form of a selective reduction agent for reducing said nitrogen oxides, wherein the particle separator (101) is placed in a main exhaust gas line (104), the ammonia generator (103) is mounted in a first auxiliary line (105) leading to the main exhaust gas line (104) opening, which is embodied in such a way that a gas flow containing the ammonia produced in the ammonia generator (103) is enable to pass through the SCR catalyst (102). The inventive method and device make it possible to simultaneously reduce the content in particles and nitrogen oxides (NOx) of the exhaust gases of an internal combustion engine (100), wherein the power consumption for said reduction is limited and the device can be entirely produced in the form of a compact unit.

Description

Method and device for the treatment of exhaust gases of internal combustion engines

The subject matter of the present invention is a method and a device for treating exhaust gases of internal combustion engines, in particular for reducing the nitrogen oxide and particulate content of these exhaust gases. Preferably, the invention finds application in automobiles.

Internal combustion engines produce exhaust gases, which are composed differently depending on the type, displacement and operating condition of the internal combustion engine. These exhaust gases must comply with legal limit values in many countries both in the stationary sector, for example in power plants, as well as in mobile use, for example in motor vehicles, boats or aircraft, which are gradually being tightened progressively. These limits can often be met only by exhaust gas treatment or aftertreatment. Since limits are to be met for a variety of exhaust gas components, also relatively complex devices and methods for exhaust aftertreatment are necessary. This requires a variety of different emission control components, the operation of each of which may affect the concentration of another component of the exhaust gas, as is the case for example in the concentration of nitrogen oxides and particles in the exhaust gas, especially of diesel engines.

In the reduction of nitrogen oxides, methods based on the selective catalytic reduction (SCR) of nitrogen oxides have been proposed. Here, a selective reducing agent such as ammonia (NH3) is used, which leads to a suitably designed catalyst for a selective catalytic reduction of nitrogen oxides. Since a direct storage of ammonia, especially in mobile requirements is problematic, was often the storage of Ammoniakprecursorn like For example, urea, isocyanic acid, cyanuric acid or ammonium carbamate proposed. In particular, the storage of urea in aqueous solution has been developed to market maturity. These systems have the after ^¬ part, that an additional reservoir for the ammonia precursor is necessary, which is disadvantageous especially in mobile applications due to the small space, especially in the passenger car area and what also requires a full-coverage system with which the ammonia precursor can be filled because without Ammonia Precursor is a reaction of nitrogen oxides completely omitted and so no reaction can take place in an empty reservoir.

Furthermore, systems have been proposed for producing ammonia on-board. For example, DE 102 58 185 A1 discloses the generation of ammonia from atmospheric nitrogen by plasma-assisted formation of nitrogen monoxide and subsequent reduction of this nitrogen monoxide to ammonia with a hydrogen-containing gas stream. This system has the disadvantage that only nitrogen oxides and not further components of the exhaust gas are considered.

On this basis, the present invention seeks to provide an apparatus and a method for reducing the concentration of nitrogen oxides and particles in the exhaust gas of an internal combustion engine, which allow simultaneous reduction of both components and which are not dependent on the entrainment of another resource.

This object is achieved by a device having the features of claim 1 and a method having the features of claim 15. Advantageous developments are the subject of the respective dependent claims.

The exhaust gas treatment device according to the invention comprises a particle separator, an SCR catalyst for the selective reduction of nitrogen oxides and an ammonia generator for generating ammonia as a selective reduction agent for the reduction of nitrogen oxides, wherein the particle separator is formed in a main exhaust line and the ammonia generator in a first secondary line, wherein the first secondary line in a Mouth opens into the main exhaust line, which is designed so that the ammonia-containing gas stream generated in the ammonia generator can flow through the SCR catalyst.

Preferably, the particle separator is flowed through by the ammonia-containing gas stream. The formation of the ammonia generator in the first secondary line means in particular that the ammonia generator can be formed in a bypass of the exhaust pipe. On the other hand, it is also possible to connect the first secondary line with the exhaust pipe so that the ammonia formed (NH3) can be fed into the exhaust pipe, but not the exhaust gas is passed through or to the ammonia generator. Particles are understood to mean, in particular, carbon-containing particles or also particles of pure carbon.

The particle separator, the SCR catalyst and the ammonia generator may each comprise at least one honeycomb body. A honeycomb body is understood to mean a body with a large wall surface, which has cavities which can be swept at least for a fluid such as an exhaust gas. A honeycomb body may for example be made of ceramic material, for example by extrusion. Furthermore, a honeycomb body can also be constructed of metallic layers. These may comprise, for example, at least partially structured layers which are spirally wound, optionally together with one or more substantially smooth layers. Another embodiment of a honeycomb body also includes metallic layers that are stacked. One or more stacks are wound in the same direction or in opposite directions. A stack can have at least one at least partially structured layer and if appropriate, comprise at least one substantially smooth layer. Also, a honeycomb body comprising a non-wound stack of at least one at least partially structured and optionally at least one substantially smooth metallic layer is possible and according to the invention.

A metallic layer is understood to mean, in particular, sheet metal foils, nonwoven fabrics, sintered porous metallic layers, wire mesh layers or combinations of at least two of these elements. An at least partially structured layer is understood as meaning a layer which, at least in some areas, has structures which form cavities after being wound up, stacked or twisted. In particular, these structures may be wave-shaped. By a substantially smooth layer is meant a layer which is smooth and optionally has microstructures. Microstructures are structures that have a structuring amplitude that is significantly smaller than the structuring amplitude of the at least partially structured layer.

The particle separator may in particular be open or closed. A closed particle separator is constructed so that the exhaust gas must pass through at least one wall of the particle separator when flowing through the exhaust gas. This can be achieved, for example, by forming the particle separator with a multiplicity of channels separated by porous walls, which are closed alternately at the end face of the honeycomb body entering the gas inlet and gas outlet, so that a first group of cavities opens with end sides open on the gas inlet side and closed on the gas outlet side and a second group of cavities with gas inlet side closed, gas outlet open end faces is present.

A particle separator may also include an open particle filter. A particle filter is called open if it can be traversed completely by particles, even of particles that are considerably larger than the particles actually being filtered out. As a result, such a fi clog even during agglomeration of particles during operation. A suitable method for measuring the openness of a particle filter is, for example, the testing of the diameter to which spherical particles can still trickle through such a filter. In the present case of application, a filter is open, in particular, when balls larger than or equal to 0.1 mm in diameter can still trickle through, preferably balls with a diameter of more than 0.2 mm.

The particle separator may be formed in particular of metal and / or ceramic foam. The particle separator may have cavities that are regular, irregular or chaotically shaped.

The SCR catalyst preferably comprises a honeycomb body which is provided with an SCR coating. This comprises, in particular, a titanium dioxide (A-natas) -supported vanadium / tungsten mixed oxide or metal-exchanged zeolites, in particular of the X, Y, ZSM-5 or ZSM-II type, preferably iron-exchanged zeolites. When forming an on-board ammonia generator, a hydrolysis catalyst which is usually required for hydrolyzing urea can advantageously be dispensed with.

The device according to the invention offers particular advantages in connection and during operation. Thus, a single device can be used which simultaneously reduces two critical and coupled exhaust components. In particular, the device according to the invention can also be controlled so that both the proportion of nitrogen oxides and of particles are reduced in the same way. The device according to the invention can be regarded as a so-called "black box", in which the user and the system planner for exhaust systems do not have to worry about the detailed functioning of the components installed in this box, but merely the connection to the exhaust system and a power supply must be made. Advantageously, the formation of the junction in such a way that the particle separator is flowed through by the ammonia-containing gas stream. Ammonia is advantageous in the regeneration of the particle separator.

The particle separator preferably comprises alternately closed channels, which are separated from one another by walls at least partially through which a fluid can flow.

Preferably, the particle separator is constructed so that an exhaust gas flow through the wall can take place. Depending on the design, the exhaust gas can flow partly through the wall, in particular in the case of an open particle separator, or also completely through the wall, in particular in such a case a closed filter with mutually closed channels can be present. The walls may preferably be formed ceramic and / or metallic.

The particle separator preferably comprises an at least partially metallic carrier. A partially metallic carrier may, for example, be a metallic honeycomb body as stated above. Another example is a ceramic carrier in which metallic structures, for example as electrodes for electrostatic agglomeration and / or separation of particles, are incorporated.

The at least partially metallic carrier preferably comprises at least one metallic layer. It is preferred here for the SCR catalytic converter, the ammonia generator and / or the particle separator to comprise a honeycomb body comprising at least one metallic layer. Furthermore, further support bodies may be formed comprising at least one metallic layer.

The particle separator preferably comprises a ceramic filter element which has metallic deposits. In particular, the ceramic filter element may be constructed in layers, in particular via corresponding "rapid manufacturing" techniques. A layered structure is understood here in particular to mean that a first layer of the body is first constructed from one or more raw materials, then solidified at least in some areas and a further layer of one or more raw materials is then applied to this solidified layer This layer is then likewise solidified at least in some areas and then the process is continued as described above until the filter element is completed.

One raw material can form the later ceramic wall, while another raw material can form the later metallic storage. The solidification can be based on a brief increase in temperature, which is achieved for example by irradiation with laser light. By a spatially selective and / or inhomogeneous heating and / or by using a raw material, which is applied spatially selective and / or inhomogeneous, so cavities separated by walls can be generated, which may for example also have microstructured walls. Furthermore, by using a plurality of raw materials, walls with regions of different properties can be constructed which, for example, have different porosities or also electrical conductivities in different regions. In this way it is also possible, based on the formation of the metallic inclusions, to specify a current distribution in the filter element after completion and thus to be able to specify in the case of an electrostatic agglomeration and / or deposition in the filter element, in which regions a separation takes place to which extent. In particular "Selective Laser Sintering", "Three Dimensional Printing" and "Fused Deposition Modeling" techniques are advantageously used for the construction. Preference is given to the formation of a particle separator which has cavities which can be swept at least for a fluid and which are at least partially separated from one another by walls.

By a cavity which can be passed through is meant, for example, a sewer closed on the end. In particular, the cavities can also be flowed through. It may further preferably be formed cavities having larger dimensions than the channels. Such cavities can preferably serve the better mixing of the exhaust gases.

Preferably, the walls have at least one of the following properties:

8.1) the walls have at least partially a coating; or

8.2) the walls comprise at least one catalytically active component.

The particle separator or the filter element - as well as all other honeycomb bodies disclosed here - can have a coating according to 8.1). This may in particular be ceramic and / or comprise a washcoat and / or zeolites. According to 8.2), the walls of the particle separator - as well as the walls of all other honeycomb bodies disclosed here - can comprise catalytically active components. These can be incorporated in a coating formed according to 8.1) or else directly in and / or on the wall, the latter preferably when these walls comprise ceramic material. The catalytically active component may preferably comprise noble metals, for example in the form of noble metal complexes. Preferably, several noble metals may be included in the catalytically active component.

The particle separator can comprise, for example, an oxidation-promoting catalytically active component, preferably in the region of one of the end faces, preferably in the flow inlet-side end face region. This can in particular catalyze the oxidation of nitrogen monoxide to nitrogen dioxide needed in continuous regeneration according to the continuous regeneration trap (CRT) principle. Furthermore, a catalytically active component can be formed on the particle separator which catalyzes the CRT regeneration reaction. Such a coating may preferably be formed throughout the particle separator. An oxidation-promoting coating can for example also catalyze an oxidation of hydrocarbons, which leads to a heating of the particle separator. The hydrocarbons can be introduced into the particle separator, for example, by operating the internal combustion engine at short notice, for example in a cylinder of the internal combustion engine in one cycle, with an increased fuel fraction, ie, fat. This leads to hydrocarbons reaching the particle separator where it can oxidize.

According to a further advantageous embodiment of the device according to the invention, the particle separator has a regeneration possibility for the regeneration of the particle separator. In this context, it is particularly preferred that the possibility of regeneration is produced by at least one of the following measures:

10.1) providing nitrogen dioxide upstream of at least a portion of the particle separator;

10.2) increasing the temperature of at least part of the particle separator above a limit temperature; 10.3) providing an oxidant upstream of at least one

Part of the particle separator; or 10.4) regeneration by an electrical discharge.

When applying one of the methods 10.1) to 10.4) to a part of the particle separator, it is understood that the appropriate measure may be applied to a part of the particle separator itself (in cases 10.1) and 10.3) or in a part of the particle separator (10.2) can take place. A regeneration possibility is understood to mean the suitability of the particle separator for the regeneration of the incorporated and / or accumulated particles, that is to say the removal of the particles from and / or from the particle separator. This regeneration possibility can be designed in particular thermally and / or chemically. If the particle separator has a thermal regeneration possibility, means may be provided which can bring about heating of the particle separator above a temperature at which oxidation of the carbon of the particles takes place, preferably also with a residual oxygen content in the exhaust gas. The particle separator may comprise catalytically active materials which catalyze such oxidation. A thermal regeneration can be achieved by increasing the exhaust gas temperature and / or by additional heating devices.

If the particle separator has a chemical regeneration possibility, it is possible to achieve a degradation of the particles by means of a chemical reaction. This can be achieved, for example, via a reaction of the carbon with nitrogen dioxide to form nitrogen monoxide and carbon dioxide. A further possibility of a regeneration possibility consists in a CRT process in which means are formed which ensure as continuously as possible a sufficiently large concentration of nitrogen dioxide in the exhaust gas in the particle separator so as to continuously convert the carbon particles. A regeneration possibility based on an electrical discharge is based, for example, on a surface sliding discharge.

According to a further advantageous embodiment of the device according to the invention, the particle separator comprises means for generating an electric field in the particle separator, by which at least one of the following functions is fulfilled: 12.1) agglomeration of particles; or 12.2) Separation of particles. Under an agglomeration of particles is here in particular the cumulation of several small particles to larger particles understood. The deposition of particles is understood to mean, in particular, the adsorption of the particles on the filter.

Particulate matter, such as particles 10 microns in diameter and less, is an undesirable exhaust gas component due to the ability of these particles to enter human lung tissue. The larger the mean diameter of the particles, the less likely it will be to take up these particles in the lung tissue. Therefore, it is advantageous, in addition to a deposition of particles, which may still lead to a later - release of the small particles, for example by mechanical effects on the Partikelabscheider agglomeration of the particles to larger particles, so as to increase the proportion of particulate matter in the Reducing the exhaust gas and allowing such average diameter of the particles to be achieved that they can not be taken up into the lung tissue predominantly.

Such an agglomeration can also be achieved by applying an electric field. The electric field can be generated, for example, by the particle separator having a ground pole and a pole at a positive potential, so that a corresponding electric field is formed, in particular transversely to a channel longitudinal axis or the direction of flow through the particle separator. Preferably, a plurality of poles, which construct such a field, may be formed parallel to each other, so that the particle separator comprises a plurality of electric fields for agglomeration and separation of particles. The fields can be operated in particular by a DC voltage, however, an operation with an AC voltage, in particular a low-frequency AC voltage with a frequency of 10 Hz or less is also possible and according to the invention. By polarizing the soot particles, they are drawn to one of the electrical poles and deposited there. The poles may, in particular with the Wan ^¬ applications of the particle separator may be combined, in particular be designed as part of this or these form itself. In this case, the formation of the particle separator made of metal foam is preferred, wherein the particle separator preferably comprises at least two components, which are in particular of the same design. Particularly preferred is the formation of the Partikelabscheiders of a metal foam, which forms a plurality of cavities, which are flowed through by exhaust gas.

The particle separator preferably comprises means for generating a second electrical field in the particle separator, by means of which a surface sliding discharge is generated for regeneration of the particle separator.

The details of the Partikelabscheiders disclosed in the context of this application can also be realized alone without the other components of the device.

According to a further advantageous embodiment of the device according to the invention, the ammonia generator comprises a plasma generator.

In particular, this may be a plasma generator as described in DE 102 58 185 A1, the disclosure content of which is incorporated in particular in relation to the operating parameters of the plasma generator, the formation of the electrodes and the addition of operating gas in the disclosure of this application. The plasma generator is preferably operated so that the operating gas heats up to temperatures of more than 2500 K in the short term. The plasma generator is operated with a nitrogen and oxygen-containing gas as operating gas, wherein the operating parameters of the plasma generator are chosen such that the reaction equilibrium of the reactions taking place in the plasma is shifted in such a way that nitrogen monoxide is preferably produced. This embroidery Substance oxide can then be reduced via an appropriately designed reduction catalyst, which is applied in particular to a honeycomb body, with the addition of, for example, hydrogen and / or hydrocarbons as the reducing agent to give ammonia. In particular, the operating gas used can be air, exhaust gas or air enriched exhaust gas.

Preference is given here to the formation of an ammonia generator, which comprises at least one storage element for the temporary storage of at least one of the following components: 15.1) ammonia or

15.2) an ammonia precursor.

An ammonia precursor is understood as meaning a substance which liberates ammonia, for example by thermal, pyro- and / or hydrolysis, or which can react with ammonia to form another starting material. Preference is given in this case to component 15.2) comprising nitrogen monoxide, since a relatively high yield of ammonia can be achieved here, in particular in cooperation with a ammonia generator comprising a plasma generator for reducing the nitrogen monoxide to ammonia at a relatively low additional fuel consumption. , The stored components 15.1) and / or 15.2) can in particular also serve as a buffer for very large NO _x occurring in the exhaust gas.

Concentrations are used, in which a relatively large amount of ammonia is needed. In addition, the storage element can be used advantageously for the intermittent storage and release of nitrogen monoxide as shown above. In addition to nitrogen monoxide, the term "ammonia precursors" also includes, for example, urea, isocyanic acid, cyanuric acid or ammonium carbamate.

It is further preferred here that the storage element temporarily stores the at least one component by sorption, in particular by chemical and / or physisorption. Physical absorption is understood to mean, in particular, storage due to physical interactions, whereas chemisorption involves adsorption based on a chemical bond. Physical absorption takes place in particular at low temperatures below a first limit temperature, while above this first limit temperature desorption of the ammonia precursor takes place. Chemisorption occurs to a significant extent above a second limit temperature, since a correspondingly shifted reaction equilibrium requires a certain temperature. By appropriate selection of the storage element, for example a correspondingly designed coating of the storage element, the first and the second limit temperature can be selected such that adsorption of nitrogen monoxide is made possible over a wide temperature range.

A corresponding coating of a honeycomb body may, for example, be designed such that a region of the coating which is farther away from a surface swept by exhaust gas is more suitable for physisorption, whereas a region closer to a surface of the coating flowed by exhaust gas is more suitable for chemisorption.

For example, it is possible to provide an ammonia generator which has at least two storage elements, one of which is filled with nitrogen monoxide, while another storage element at least partially releases the nitrogen monoxide stored in it, so that it can be reduced to ammonia. In particular, the delivery of the nitrogen monoxide into a hydrogen-containing and preferably oxygen-poor gas stream can take place here. This reduces the required hydrogen content, since hydrogen would normally first react with oxygen. If the operating gas of the plasma generator comprises at least air, then the oxygen content of the operating gas when leaving the plasma generator is still relatively high, for example in the range from 18% to 19%. If now a low-oxygen, hydrogen-containing gas is used in which or in which the provision of the nitrogen monoxide is made, the demand for hydrogen is much lower than when the working gas directly would mixed with egg ^¬ nem hydrogen-containing gas.

The hydrogen-containing gas may in particular be a cracking or synthesis gas which is produced by partial oxidation of hydrocarbon. In particular, the fuel used for operating the internal combustion engine can serve as starting material for the cracking or synthesis gas. Since the required hydrogen content is reduced, the fuel consumption also decreases compared to conventional systems. The plasma generator can be operated intermittently with two gas strands, each comprising a storage element for the temporary storage of nitrogen monoxide and optionally a reduction unit for the reduction of nitrogen monoxide to ammonia. If appropriate, the reduction unit for the reduction of nitrogen monoxide to ammonia can also be charged together by the two gas strands. Furthermore, it is possible to form memory element and reduction unit in a single component, for example by forming a honeycomb body with a corresponding storage reduction coating.

The generation of fission and / or synthesis gas can be carried out in a suitably designed reformer or reactor, preferably in a second secondary strand. Preference is given here to the production of the cracking and / or synthesis gas by partial oxidation of hydrocarbons. The second secondary line is in particular designed so that it opens in front of the at least one Speicherele- ment in the first secondary line, so that the at least one storage element can be flowed through by the cracking and / or synthesis gas.

Furthermore, the ammonia generator may alternatively or cumulatively comprise means which accumulate nitrogen monoxide in a gas stream, for example by separating a gas stream containing nitrogen oxides (NO _x ) into a first gas stream in which the relative proportion of NO to NO _{x is} increased and a second one Gas flow in which the relative proportion of NO2 to NO _{x is} increased. This is possible for example by appropriate membrane.

Another possibility is a storage element which can selectively store only nitrogen monoxide but not nitrogen dioxide. This can be achieved by appropriately designed molecular sieves, in particular zeolites. Such a storage element can then be traversed by exhaust gas until a certain amount of nitrogen monoxide is stored. Then, for example, by changing a physical and / or chemical process variable, the nitrogen monoxide temporarily stored in this storage element can be dissolved out and released into a hydrogen-containing gas stream, whereupon a reduction to ammonia by a corresponding catalyst is also catalyzed.

The possibilities described here of enriching or storing nitrogen monoxide directly from the exhaust gas can preferably also be implemented in the main exhaust gas stream and, in particular, without a particle filter or an SCR catalyst being formed.

Preferably, the ammonia generator comprises means for supplying a reducing agent for the reduction of nitrogen monoxide to ammonia. Preferably, these are connectable to a reservoir of the reducing agent and / or a reducing agent forming reactor and / or reformer. It is furthermore preferred that the reducing agent comprises at least one of the following substances:

19.1) hydrocarbons or

19.2) hydrogen.

Preference is given to the formation of first reduction devices, which are designed so that on or in them a reduction of nitrogen oxides, preferably from

Nitric oxide, with the reducing agent 19.1) and / or 19.2) can be carried out. In particular, a reaction with nitrogen oxides in bound form can be carried out, for example with chemisorbed nitrogen oxides, which are present in the form of nitrite or ratgruppen Nit ^¬.

In particular, means for providing and / or generating the reducing agent are formed. These include in particular a reformer and / or a reactor for the partial oxidation of hydrocarbons. The means for supplying the reducing agent preferably comprise a mixer which is suitable for mixing the reducing agent with another gas. This may be an active and / or a passive mixer.

According to a further advantageous embodiment of the device according to the invention, the first secondary line is traversed by at least one of the following gases: 24.1) exhaust gas;

24.2) a gas comprising at least oxygen and nitrogen; or

24.3) air.

In this case, according fiction, any mixing ratios of the gases 24.1), 24.2) and 24.3) occur. In particular, the first secondary line flows through pure exhaust gas, preferably when the exhaust gas has a high oxygen content, for example when the internal combustion engine is a diesel engine. Furthermore, the first secondary strand can be traversed by pure air. In particular, when a plasma generator is included in the ammonia generator, it may be advantageous to design the first secondary line such that, in addition to the gases 24.1), 24.2) and / or 24.3), a hydrogen-containing gas can flow through the secondary line, so as to reduce it from nitric oxide to ammonia. The first secondary line is preferably designed such that the ratios of the gases 24.1), 24.2) and / or 24.3) are adjustable and / or changeable relative to one another. According to a further advantageous embodiment of the device according to the invention, the particle separator comprises means for generating an electric field in the particle and the ammonia generator a plasma generator, wherein at least one control device for generating and controlling the electric field of the Partikelabscheiders and for driving the plasma generator is formed.

In particular, the formation of a single control device is advantageous both for the particle separator and for the plasma generator, since the operating conditions of both components can be optimally adjusted to one another. In particular, an operating method in which the particle fraction, the particle size distribution and / or the nitrogen oxide content can likewise be reduced or changed can be carried out by a common control device. Furthermore, such a method can be carried out, in which, in addition to an adjustable or selectable reduction or modification of the above-mentioned parameters, the lowest possible energy and / or additional fuel consumption is achieved at the same time. For this purpose, the control device can also be connected to corresponding sensors, for example temperature sensors, lambda probes, gas partial pressure sensors, etc.

The means for generating an electric field comprise in particular electrodes in the particle separator and a voltage source which is electrically connectable to the electrodes in the particle separator. Preference is given to the formation of a single control device, via which both the means for generating an electric field in the particle separator and the plasma generator are controlled and optionally supplied with electrical energy. In particular during the cold start, the means for generating an electric field in the particle separator can be supplied with electrical energy in an advantageous manner, after which the plasma generator is also supplied with electrical energy after a predefinable period of time. This has the advantage that the particles are generally agglomerated and / or precipitated while a reaction The nitrogen oxides only take place when the SCR catalytic converter has reached its minimum operating temperature ("light-off temperature"). However, this operating temperature reaches the SCR catalyst only after a certain time.

The ammonia generator described in this application, as well as the first secondary strand, can also be realized in an advantageous manner even in isolation, ie without the other components of the device according to the invention.

According to a further advantageous embodiment of the device according to the invention, an oxidation catalyst is formed at at least one of the following locations:

26.1) upstream of the particle separator;

26.2) downstream of the ammonia generator and upstream of the SCR catalyst; or

26.3) downstream of the SCR catalyst.

At point 26.1), the oxidation catalyst can in particular catalyze the oxidation of nitrogen monoxide to nitrogen dioxide and thus provide a regeneration possibility for the particle separator. At point 26.3), the oxidation catalyst can serve as a barrier catalyst, which effectively prevents the breakthrough of, for example, ammonia and / or hydrocarbons. At point 26.2), the oxidation catalyst can advantageously serve the consumption of oxygen, which may contain the gas leaving the particle separator. The coatings of the oxidation catalyst, in particular with regard to the nature and concentration of the catalytically active substances used, can be adapted differently to the respective catalysts to be catalyzed at the oxidation catalysts at points 26.1), 26.2) and 26.3). According to a further advantageous embodiment of the device according to the invention, this comprises a first flow region and at least one second flow region, which can be flowed through substantially parallel to each other, wherein the first flow region is at least a part of the main exhaust line, wherein the first and the second flow region are formed so that a heat input from the first flow region into the at least one second flow region can take place.

Preferably, the flow areas are coaxial and / or concentric. Furthermore, it is preferred that at least one of the following components is formed in a second flow region:

31.1) at least one plasma generator

31.2) at least one reformer or

31.3) at least one reactor.

Preferably, in a first second flow region, a plasma generator and in a second second flow region, a reformer or reactor is formed, which in particular generates hydrogen via a partial oxidation of hydrocarbons. Further preferred is a development in which the first and the at least one second flow region are separated from each other by at least one partition wall.

In particular, the first flow region lies on a first side of the dividing wall, while the second flow region is formed on a second side of the dividing wall. The partition may be formed one or more layers. In particular, it is preferred to form the two flow regions by surface-integral connection of two conventional tubes, wherein the tubes may optionally still be deformed. In addition to a coaxial design of the first and second flow region and a concentric arrangement of these areas is possible and according to the invention. The device according to the invention permits the guidance of exhaust gas in a first partial flow in the first flow region and in a second exhaust gas flow in a second flow region. Since the components 31.1) ,. 31.2) and / or 31.3) is formed only in the first flow area, it can thus be ensured, for example, without major design effort, that only an exhaust or partial gas stream is subjected to plasma treatment in a flow region or partial only in an exhaust or partial gas stream Oxidation of hydrocarbons takes place. In particular, a plasma generator can be integrated very compactly in the exhaust system of motor vehicles. In particular, the plasma generator is designed so that the exhaust gas is heated in the plasma generator by the gas discharge to temperatures above 2000 Kelvin, preferably even over 2800 Kelvin. In operation, molecular nitrogen, which is present in both the exhaust gas and in the - optionally zugebbaren - air, and oxygen electronically excited, disassociated and ionized by non-thermal, plasma-induced collision processes with high-energy electrons. Nitrogen oxides are preferably formed by reactions of the electronically excited molecules, radicals and ions with the exhaust gas heated by the plasma. Nitrogen monoxide (NO) is preferably formed on account of the high applied temperature, since the reaction equilibrium at these temperatures correspondingly prefers the formation of nitrogen monoxide and that of nitrogen dioxide. The response times are in the range of less than 10 milliseconds.

Thus, the concentration of nitric oxide can be increased during operation by the plasma generator. This nitrogen monoxide may furthermore preferably be reduced to ammonia. The plasma generator can be constructed, for example, as described in DE 102 58 185 A1, the content of which is completely included in the disclosure content of this application with regard to the construction and operation of the plasma generator.

In the region of the plasma generator, the device has suitable connections with which the plasma generator with a corresponding power supply and a corresponding controller can be connected. Corresponding insulation and the like may be designed according to the invention.

If the plasma generator is operated in such a way that the exhaust gas is locally heated by the gas discharge to fairly high temperatures, such as 2800 Kelvin and more, in the presence of molecular nitrogen (N2), on the one hand, it reacts with oxygen radicals formed by the plasma Nitrogen monoxide and nitrogen are formed and, on the other hand, to the reaction of such a nitrogen atom with molecular oxygen (O2) to nitrogen monoxide and an oxygen radical. Further reactions are rather of minor importance at relatively high temperatures, so that a high yield of nitrogen monoxide can be achieved by use and corresponding operation of the plasma generator.

Preferably, the at least one second flow region is formed at at least one of the following locations:

32.1) upstream of a storage element;

32.2) upstream of a reformer or reactor; or

32.3) upstream of a plasma generator.

Thus, advantageously, a heat input into the respective operating gas of the storage element, the reformer or reactor and / or the plasma generator, so that the energy to operate these components and thus the overall system can be reduced. In particular, the heat of the exhaust gas, which can flow through the first flow region, can thus be used for heating the storage element, the reformer or reactor and / or the plasma generator. In particular, an education at the point 32.1) is advantageous if sorption takes place on the storage element. Gas supply means are preferably provided in an axial preferred flow direction upstream of the plasma generator, in particular for supplying a gas comprising oxygen and / or nitrogen.

The gas supply means may be formed both in the first flow region and in a part of the exhaust gas treatment unit in which the flow regions are not yet separated from one another. Such a region can be formed upstream, for example, by the fact that the dividing wall is not yet formed there.

For example, ambient air can be supplied as gas comprising oxygen. This has the further advantage that molecular nitrogen is supplied to the system, which can serve in the same way for the formation of nitrogen monoxide. In this case, it is basically possible to supply air, for example via a compressor, under pressure.

Preferably, at least in an axial preferred flow direction downstream of the first and the second flow region, a common third flow region is formed. In this, the two gas flows formed by the separating wall can flow together again after flowing through the respective flow areas and are in particular mixed there. In this area, when the plasma generator is operated to produce nitrogen monoxide in the second flow area, formation of a nitrogen oxide-enriched total exhaust gas flow occurs that includes both partial exhaust gas streams flowing through the two flow areas. It is also possible to provide for the reduction of the nitrogen monoxide to ammonia before merging the two gas streams by, for example, a corresponding catalyst is introduced, for example, on a catalyst carrier body in the first flow region downstream of the plasma generator. Preferably, in a preferred axial flow direction downstream of the plasma generator, a first honeycomb structure is formed with a first reduction catalyst coating for reducing oxygen.

This first honeycomb structure can serve in particular for removing the residual oxygen from the exhaust gas flow. This residual oxygen content can be high, especially when air has been supplied via the gas supply means. The first reduction catalyst coating used is, in particular, a ceramic coating material such as, in particular, washcoat, in which components containing precious metals, for example platinum and / or palladium, are introduced.

Preferably, in a preferred axial flow direction downstream of the plasma generator, a second honeycomb structure with a second Reduktionskataly- satorbeschichtung for reducing nitrogen oxide to ammonia formed. The second reduction catalyst coating comprises, in particular, platinum and / or palladium as active components; in particular, only little rhodium is present in this coating, preferably substantially no rhodium.

Thus, the two flow range allow the provision of a compact on-board ammonia generator, which can be used in particular in mobile applications in the exhaust system of internal combustion engines. The ammonia which can be produced in this way can serve downstream as a reducing agent in a selective catalytic reduction (SCR) process of nitrogen oxides. In mobile applications in particular, the formation of tanks for reducing agents such as, for example, ammonia precursors (eg urea, ammonium carbamate, isocyanic acid, cyanuric acid, etc.) in solution or as a solid can thus be dispensed with.

By a corresponding embodiment of the second Reduktionskatalysatorbe- layering of the second honeycomb structure, other reactions can be catalyzed by which instead of ammonia other reducing agents such as se isocyanic acid or cyanuric acid are generated. Also such reducing agents and corresponding second reduction catalyst coatings are possible and according to the invention. The second reduction catalyst coating comprises in particular noble metals as catalysts such as platinum. The second reduction catalyst coating comprises, in particular, titanium dioxide (anatase) -treated vanadium / tungsten oxide or else metal-exchanged zeolites, in particular zeolites of the type X, Y, ZSM-5 or ZSM-11.

Reduction supply means for supplying a reducing agent are preferably formed in the flow direction between the plasma generator and the second honeycomb structure. If a first honeycomb structure is also formed for the reduction of, in particular, the remaining oxygen, the reduction feed means are preferably formed between the first and the second honeycomb structure.

As a reducing agent for the reduction of nitrogen monoxide to ammonia, in particular hydrocarbons have proven. These can be obtained in a simple manner from the fuel of the internal combustion engine. For example, it is possible to inject fuel, in particular diesel fuel, of the internal combustion engine via the reduction supply means directly into the exhaust gas flow upstream of the second honeycomb structure. In particular, the reduction feed means are designed as nozzles. The reduction supply means are in particular designed so that the most uniform possible concentration of the reducing agent over the flow cross-section is achieved. In particular, it has been proven to spray the reducing agent in the form of small droplets.

In the common flow region, a mixer, in particular a mixer structure, is preferably formed.

A mixer structure may for example consist of a honeycomb structure which has openings between the individual channels, through which the exhaust gas can flow at least partially substantially transversely to the flow direction. This causes the mixing of the exhaust gas flow. Particularly preferred here is the formation of conductive structures in the channel wall, which guide the exhaust gas flow toward the openings located between the channels.

A third honeycomb structure with an SCR catalyst coating is preferably formed in the flow direction downstream of the second honeycomb structure.

This SCR catalyst coating is a coating containing a catalyst that catalyzes the selective catalytic reduction of nitrogen oxides. The SCR catalyst coating comprises, in particular, titanium dioxide (anatase) -treated vanadium / tungsten oxide or else metal-exchanged zeolites, in particular zeolites of the type X, Y, ZSM-5 or ZSM-11.

In operation, it may thus come to molecular nitrogen due to the ammonia component formed in the second honeycomb structure for the selective catalytic reduction of the nitrogen oxides. As a result, the nitrogen oxide emissions of the internal combustion engine are effectively reduced.

It is particularly advantageous in this context if means for temporary storage of a reducing agent are formed between the second honeycomb structure and the third honeycomb structure.

In particular, these are means for the temporary storage of the reducing agent, which is formed in the preceding process step. In particular, they are agents for the temporary storage of ammonia. However, other reducing agents can be stored accordingly, such as, for example, isocyanic acid or cyanuric acid.

The formation of means for temporary storage allows the presence of a certain amount of reducing agent, which can then be used when a very rapidly very high concentration of To reduce nitrogen oxides. In order to eliminate the possible inertia of the system for generating the reducing agent here, the provision of a certain amount of reducing agent in the means for temporary storage is advantageous. In particular, these agents may be coated honeycomb structures, which are coated in particular with certain zeolites, such as zeolites of types A, X, Y or ZSM-5.

Particularly advantageous here is the formation of a control circuit with which, on the one hand, the concentration of nitrogen oxides in the exhaust gas is determined directly or indirectly, which further detects the amount of incorporated reducing agent in the temporary storage means. In this case, in particular the generation of nitrogen monoxide in the plasma generator is regulated, for example via switching the plasma generator on and off, a change in the current intensity and / or frequency or even a change in the gas composition, for example by supplying or changing the amount of an oxygen-like gas. It is particularly advantageous in this case if the control tries in a certain way to anticipate the extrapolation of the content of nitrogen oxides in the exhaust gas of the internal combustion engine at a future time. This can be done, for example, by observing the nitrogen concentration in addition to the nitrogen oxide concentration by means of a memory module and a differentiator and the slope of the nitrogen concentration. Thus, it is possible in a simple manner to extrapolate the nitrogen oxide concentration in the future and thus also to be able to make estimates for the required amount of reducing agent. According to this estimate, the generation of nitrogen oxides and subsequently of ammonia can take place.

In this context, it is particularly preferred that in the direction of flow in front of the common wall between the first and the second flow region flow guide means are formed, which allow the Abgasteilstroman- part, which flows in the first flow region set. Basically, by the formation of the partition per se, a division of the exhaust gas flows to the first and the second flow region. In this situation, a first partial exhaust gas stream flows into the first flow area and a second partial exhaust gas flow into the second flow area. Depending on the connection, it may be necessary for the first partial exhaust gas flow, which flows through the first flow region, to be greater or smaller than the first geometric partial exhaust gas flow. For example, it is advantageous to conduct only a very small mass flow through the first flow region and relatively large mass flows through the second flow region. If, in such a case, due to, for example, the space requirement of the plasma generator or the reformer / reactor, the first partial exhaust gas stream is greater than the required partial exhaust gas flow, it may be necessary to form means in the front flow zone of the wall, which reduce the partial flow of exhaust gas flowing into the first flow region , This may, for example, consist in an entanglement in this area or else in a movable flap which makes the proportion of exhaust gas flow variable. Preference is also given to the formation of flow-guiding means in which essentially the entire mass flow is passed through the second flow region. In such a case, it must be ensured that the operating gas, which is supplied to the plasma generator, contains sufficient nitrogen in addition to oxygen. For example, here air can be used as operating gas.

Regardless of the formation of flow-guiding means, the first flow region can also be formed on the input side substantially closed. This means in particular that essentially no exhaust gas can flow into the first flow region. In such a case, it is preferred that the first flow region is designed such that the operating gas for the plasma generator, for example air, can flow into the first flow region and the exhaust gas heats the operating gas through contact with the common wall. It is advantageous to preheat the operating gas of the reformer / reactor and / or the plasma ^¬ generator. This can be done by an electrical resistance heater or by a heat input from the exhaust. It may furthermore be part way before ^¬, to cool the gas which flows in at least one storage element in the desorption temperature is exceeded in the physisorption or chemisorption by addition of air.

The embodiment of first and second flow regions described in this application can also be realized advantageously independently of the remaining embodiment of the device, that is to say in isolation, and is also inventive in its own right.

Preferably, a mixer is formed at at least one of the following points: 39.1) at the junction of the first secondary strand into the main strand; 39.2) upstream of the particle separator; or

39.3) at the junction of the second secondary strand into the first secondary strand.

The at least one mixer can be designed here as an active mixer and / or as a passive mixer. For example, a passive mixer includes a mixer structure as described above. Furthermore, the particle separator can also comprise a passive mixer, that is to say a mixing, in particular a cross-mixing of the gas streams flowing through it. An active mixer is understood in particular to mean a turbine or a turbocharger. Furthermore, the mixer can be designed as a swirl mixer.

The mixing of gas streams, for example of the ammonia-containing gas stream with the main exhaust gas stream, can preferably take place by means of an active mixer, for example a turbocharger. Furthermore, it is possible to mix the gas streams to be mixed tangentially. Furthermore, a mixer may be formed which has, for example, a honeycomb body with channels of a first repetition length and holes or caverns which have a dimension, which is greater than the repetition length. Furthermore, the channel walls may have apertures of dimensions substantially smaller than the repetition length of the structures and conductive structures directing a gas flow into an adjacent channel.

Furthermore, it may be advantageous to also drive the ammonia-containing gas stream through the particle separator. In particular, the ammonia-containing gas stream can have a positive effect on the regeneration of the particulate filter. In such a case, the particle separator can also advantageously effect the mixing of the ammonia gas stream with the main exhaust gas stream. In such a case, a structure of the device may be selected in which the first secondary line opens into the main exhaust line upstream of the Partikelabscheiders and the SCR catalyst.

Also preferred is a further development of the device in which flow line means are formed, which make it possible to adjust an exhaust gas or gas flow component which flows into the first secondary line. These flow conduit means may comprise throttle valves and / or valves.

Advantageously, the enrichment of nitrogen monoxide in the cold start phase takes place only when the at least one memory element formed downstream of the plasma generator is in an operating state which permits sorption of nitrogen oxides. In particular, this is the case with chemisorbing storage elements at temperatures above about 200 ° C the case.

In principle, a plurality of storage elements may be formed in series, in addition downstream of a reduction device may be formed, on which a reduction of nitrogen oxides, preferably nitrogen monoxide, is catalysed to ammonia. The formation of, for example, two storage elements, one of which is based on physisorption and one on chemisorption, is possible and according to the invention. Ammonia is preferably not provided until the SCR catalyst has reached its operating temperature above the light-off temperature, which preferably has a coating in which ammonia can be stored be used by occurring nitrogen oxide in the exhaust gas.

Preferably, the method can be designed so that during operation a positive heat transfer takes place before or into a chemisorption-based storage element, in order to keep it above the limit temperature, from which the corresponding reaction proceeds to a significant extent. Preferably, the method can be designed so that during operation, a negative heat transfer takes place before or in a physisorption based storage element to keep it below its desorption temperature.

Preferably, an air supply means such as a blower or compressor may be formed, which supplies the plasma generator with air as at least a part of its operating gas.

Preferably, a temperature and / or concentration monitoring of the gas flows with a computer-based model, in which data on other points of the system are calculated via input data, for example, at least one sensor or even from the engine management.

Preferred is an embodiment of the device in which the SCR catalyst and the particle separator form a unit. It is particularly preferred here that the same surfaces serve both for particle separation and / or agglomeration, and for catalyzing the SCR process.

The connection of particle separator and SCR catalyst to a unit advantageously allows the construction of a compact erfϊndungsgemäßen Contraption. By using a surface for both particle separation and SCR catalysis, a more compact design of the unit becomes possible.

It is furthermore preferred that the SCR catalyst is designed such that a first amount of reducing agent, preferably ammonia, can be stored in it, in particular by a corresponding configuration of the coating of the SCR catalyst.

Also preferred is an embodiment of the device according to the invention, in which at least one turbine is formed in the main exhaust line and the first secondary line branches off from the main exhaust line in front of the turbine. It is particularly preferred here that the first secondary line opens into the main line after a turbine. The pressure gradient created by the turbine can advantageously be used for metering the amount of gas flowing into the first secondary line, for example by means of a flutter valve. A turbine is understood here in particular as a turbocharger. If two or more, in particular serial, turbochargers are formed in the system, the junction with one and in front of another turbocharger can advantageously take place.

It is furthermore preferred that means are provided for regulating the amount of gas flowing into the first and / or second secondary line. In particular, these means comprise a flutter valve and / or a movable flap. Thus, advantageously, the operating conditions of the ammonia generator formed in the first secondary line can be adjusted and adjusted.

It is further preferred that the reformer and / or reactor is provided with an operating gas, which at least partially an exhaust gas recirculation line can be removed. Preference is also given to a device in which all components of the device, ie in particular the ammonia generator, the particle separator and the SCR catalyst are formed in a common housing. This advantageously allows easy connection to the exhaust system, the device can thus be used as a "black box" especially for retrofitting exhaust systems.

According to a further aspect of the inventive concept, a method for the treatment of exhaust gas is proposed, are at least partially deposited by a particle in the exhaust particles and are at least partially reduced in the nitrogen oxides in the exhaust gas in an SCR catalyst, wherein the deposition of the particles in a Main exhaust gas is carried out and ammonia is generated in a first secondary strand, which is fed to the SCR catalyst as a reducing agent.

In this case, the generation of the ammonia in the first secondary strand from at least one educt which is gaseous at room temperature is preferred. Furthermore, the production of ammonia from a gaseous nitrogen source at room temperature is preferred. In particular, air and / or exhaust gas can serve as nitrogen source.

According to an advantageous embodiment of the method according to the invention, the first secondary line and the main exhaust line are combined so that the ammonia-containing gas stream generated in the first secondary line can flow through the particle separator.

According to a further advantageous embodiment of the method according to the invention, at least one electric field is formed in the particle separator, which performs at least one of the following functions: 58.1) agglomeration of the particles, 58.2) deposition of the particles, or 58.3) Regeneration of the particle separator.

An agglomeration according to 58.1) is understood to mean the attachment of particles to particles, so that particles with larger average diameters are formed. This can be done in particular by applying a DC voltage or a low-frequency AC voltage. A separation in the sense of 58.2) is understood to mean the removal of the particles from the exhaust gas stream. 58.3) is understood to mean the removal of particles by means of an electric field.

According to a further advantageous embodiment of the method according to the invention, the particle separator has a regeneration possibility for the regeneration of the particle separator. It is particularly preferred here for the regeneration possibility to be based on at least one of the following mechanisms: 60.1) provision of nitrogen dioxide upstream of at least part of the particle separator;

60.2) raising the temperature of the particle separator above a limit temperature;

60.3) providing an oxidant upstream of at least a portion of the particle separator; or

60.4) Regeneration by an electrical discharge.

A regeneration of a particle separator is understood in particular to mean the removal of the separated particles from the particle separator. A regeneration possibility is understood to mean the suitability of the particle separator for the regeneration of the incorporated and / or deposited particles, that is to say the removal of the particles from and / or from the particle separator. This regeneration option can be designed in particular thermally and / or chemically.

If the particle separator has a thermal regeneration option according to 60.2), means may be provided which allow the particle removal to be heated up. cause separators over a temperature at which an oxidation of the carbon of the particles takes place, preferably also with a residual oxygen content in the exhaust gas. The particle separator may comprise catalytically active materials which catalyze such oxidation. A thermal regeneration can be achieved by increasing the exhaust gas temperature and / or by additional heating devices.

If the particle separator has a chemical regeneration capability according to 60.1) and / or 60.3), it is possible to achieve a degradation of the particles by means of a chemical reaction. This can be achieved, for example, via a reaction of the carbon with nitrogen dioxide to form nitrogen monoxide and carbon dioxide. A further possibility for regeneration consists in a CRT process, in which means are formed which ensure, as continuously as possible, a sufficiently large concentration of nitrogen dioxide in the exhaust gas in the particle separator so as to continuously convert the carbon particles. For example, a regeneration option based on an electrical discharge according to 60.4) is based on a surface slip discharge.

According to a further advantageous embodiment of the method according to the invention, ammonia is produced by a plasma-assisted generation of nitrogen monoxide and subsequent reduction to ammonia.

With regard to the production of nitric oxide by a plasma, reference is made to DE 10258185 A1, the disclosure of which is included in the disclosure of this application.

In this case, a plasma generator is preferably operated with a first operating gas comprising at least nitrogen and oxygen. In particular, here air and / or exhaust gas can be used as operating gas. Also preferred is a method in which the ammonia generator preferably at least? a memory element comprises, in which nitrogen oxides are reversibly storable.

The reversible storage of nitrogen oxides, it is possible to provide two gas strands that are connectable to the plasma generator, so that each stored in a gas line nitrogen oxides and released in another nitrogen oxides, which can then be reduced to ammonia. Preference is given to memory elements comprising honeycomb body with a Speicherreduktionsbe- layering, in which nitrogen oxides are chemisorbed as nitrites and / or nitrates.

Further preferred is a method in which at least two storage elements are formed, wherein nitrogen oxides are stored in at least one storage element, while stored from at least one storage element stored nitrogen oxides. Further preferred in this context is a method in which nitrogen oxide is stored and dissolved out alternately in each storage element.

Preference is given to an embodiment of the method in which the storage of nitrogen oxides is based on physical and / or chemisorption.

Furthermore, a method is preferred in which the storage and removal of the nitrogen oxides takes place as a function of at least one physical and / or chemical process variable. Particularly preferably, the at least one process variable in this context comprises at least one of the following variables:

69.1) temperature of the exhaust gas;

69.2) temperature of the storage element; or

69.3) concentration of a component of the gas flowing through the storage element. Particularly preferred in this context is a process in which the process quantity according to 69.3) comprises the concentration of at least one of the following: 70.1) hydrogen or 70.2) hydrocarbons.

Preference is given here to the provision of the substance 70.1) by a reformer and / or reactor, in particular by partial oxidation of hydrocarbons. In this case, the reformer and / or reactor is preferably formed in a second secondary line.

It when the second secondary line opens into the first secondary line upstream of the storage element is particularly advantageous. Preferably, the second secondary line, in particular upstream of the reformer and / or reactor, be heated, in particular by the waste heat of the exhaust gas. A direct heating of the reformer and / or reactor is possible and according to the invention. In addition to or in addition to a heating by the waste heat of the exhaust gas, an additional heating can take place, for example by an electrical resistance heater. The second secondary line can be charged with hydrocarbons and, if appropriate, air as operating gas.

Preferably, the storage of nitrogen oxides takes place at temperatures substantially below a first limit temperature due to physisorption.

Further preferred is a method in which the storage of the nitrogen oxides takes place at temperatures substantially above a second limit temperature due to chemisorption.

In this context is preferred 76.1) a storage element is formed on or in which a reversible storage of the nitrogen oxides takes place essentially by physical and chemical absorption or

76.2) at least two storage elements are formed, wherein on or in at least one of these storage elements is a reversible storage of nitrogen oxides substantially by physisorption and on or in at least one other storage element reversible storage of nitrogen oxides substantially by chemisorption, wherein the at least one memory element so is designed so that the first limit temperature is substantially greater than the second limit temperature.

In option 76.1), a honeycomb body may comprise a corresponding coating which comprises, for example, a zeolite or a similar molecular sieve for physisorption, which is suitably designed such that chemisorption occurs alternatively or cumulatively.

Furthermore, a method is preferred in which a storage temperature is present at the at least one storage element, a reformer temperature at at least one reformer, an exhaust gas temperature in the exhaust gas, with a positive heat transfer from the exhaust gas or a negative heat transfer from at least one of the following components:

77.1) at least one memory element or

77.2) at least one reformer or reactor, the heat transfer meeting at least one of the following conditions:

77.1.a) the heat transfer to or from a storage element, at which predominantly physisorption occurs, is controlled and / or controlled such that the storage temperature is substantially below the first

Limit temperature remains, 77.1.b) the heat transfer to or from a storage element at which predominantly chemisorption occurs, regulated and / or controlled is that the storage temperature substantially above the second limit temperature and below a third limit temperature, above which a desorption of the nitrogen oxides takes place, or

77.2.a) the heat transfer to or from a reactor is controlled and / or controlled such that the reactor temperature is within a range in which the reactor produces hydrogen-containing gases.

According to a preferred embodiment of the method, an enrichment of nitrogen monoxide by a plasma generator takes place when a storage temperature of at least one at least partially chemisorption-based storage element is above the second limit temperature.

Further preferred is a method in which the mass flow of the first operating gas for the plasma generator substantially corresponds to a first predetermined value when the storage temperature of a partially chemisorption based storage element is below the second limit temperature and above a second predetermined value, which is greater than the first predetermined value is, if the storage temperature is above the second limit temperature.

Basically, a method is preferred in which the above-mentioned temperatures are at least partially determined by a computer-based model.

Also particularly preferred, and in particular in this connection, is the detection of at least one temperature via a measuring sensor.

According to a further advantageous embodiment of the method according to the invention, the production of ammonia is regulated and / or controlled as a function of the NOx and / or the ammonia concentration in the exhaust gas. In this context, it is particularly preferred that a NOx and / or an ammonia content of the exhaust gas is detected via a measuring sensor. Here kan _™ in particular, an indirect determination of NOx and / or ammonia content of the exhaust gas occur in the recorded another concentration over a sensor and then from this, the NOx and / or Ammoniakkon- obtain concentration. Furthermore, several sensors may be formed in the exhaust system.

According to a further advantageous embodiment of the method according to the invention, the NOx concentration is determined from the operating data of the internal combustion engine.

In particular, it is possible to deduce the NOx concentration in the exhaust gas from the engine map. An adaptation of the NOx concentration concentration value on the basis of measured values is possible in an advantageous manner.

Particularly preferred is a process control in which at least one turbine is formed in the main exhaust line and the first secondary line branches off from the main exhaust line upstream of the turbine. It is further preferred that the first secondary line after a turbine opens into the main exhaust line.

In this case, the pressure gradient resulting from the turbine can advantageously be used to regulate the operating gas flow in the first secondary line. In particular, means for regulating the operating gas flow may be formed, for example a flutter valve or the like.

Advantageously, the amount of gas flowing into the first and / or second secondary line is regulated and / or controlled, preferably by a flutter valve and / or a movable flap. Preferred is a development of the method in which the reformer and / or reactor is charged with an operating gas which is at least partially an exhaust gas recirculation line can be removed.

In particular, the exhaust gas recirculation line can be connectable via corresponding flow line means to a second secondary line in which the reformer and / or reactor is formed. About this flow line means, the gas mass flow can be controlled and / or regulated by the second secondary strand in an advantageous manner.

It is also particularly preferred that the reformer and / or reactor and / or the plasma generator is charged with an operating gas which is preheated.

The preheating can be done in particular by electrical heating and / or by using the waste heat of the exhaust gas.

The details disclosed for a device according to the invention can be transferred in the same way to the method according to the invention. In particular, the description of the components used, such as the Partikelabscheider, the ammonia generator, the SCR catalyst, the honeycomb bodies, etc. can be transferred directly to the inventive method.

In the following, the invention will be explained with reference to the attached figures, without these being limited to the exemplary embodiments shown there. Show it:

Figure 1 shows schematically a first embodiment of an exhaust gas treatment unit as part of a device according to the invention in longitudinal section; FIG. 2 is a longitudinal sectional view of a second exemplary embodiment of an exhaust gas treatment unit as part of a device according to the invention;

3 shows schematically a first exemplary embodiment of an exhaust system;

Figure 4 schematically shows a second exemplary embodiment of an exhaust system;

FIG. 5 schematically shows a cross section through an exhaust gas treatment unit as part of a device according to the invention;

FIG. 6 schematically shows a first exemplary embodiment of a device according to the invention;

Figure 7 schematically shows a second embodiment of a device according to the invention;

FIG. 8 schematically shows a first example of a particle separator;

FIG. 9 schematically shows a second example of a particle separator;

FIG. 10 shows schematically a third exemplary embodiment of a device according to the invention;

Figure 11 shows schematically an example of an ammonia generator; and

FIG. 12 schematically shows an example of a particle separator.

FIG. 1 schematically shows a longitudinal section of a first exemplary embodiment of an exhaust gas treatment unit 1, which may be part of a device according to the invention, but which also functions without the other components of the present invention. The device can be realized in an advantageous manner. The exhaust gas treatment unit 1 comprises a first flow region 3 and a second flow region 2, which can be flowed through substantially parallel to one another and are separated from one another by a partition 4. In the second flow region 2, a plasma generator 5 is formed. The second flow region 2 is part of the first secondary strand 105, the first flow region 3 is part of the main exhaust line 104. When forming an alternative or cumulative second flow region 2 with a reactor 133 and / or reformer 111, the second flow region 2 can be part of the second secondary strand 110 ,

In the present example, a plasma generator 5 is formed in the second flow area 2, which in particular may be designed according to one of the types shown in DE 102 58 185 A1. The plasma generator comprises a first electrode 6 and a second electrode 7. The second electrode 7 is funnel-shaped around the plasma channel 8. In the plasma channel 8, a plasma is generated upon application of the electrodes 6, 7 with a high voltage, which may be formed as a DC or AC voltage. By means of this plasma, which briefly causes gas temperatures of more than 2500 Kelvin, there is an increased conversion of nitrogen and oxygen to nitrogen monoxide. The electrical power supply via the connections. 9

FIG. 2 schematically shows a second exemplary embodiment of an exhaust gas treatment unit 1 having a first flow region 3 and a second flow region 2, which may in particular be part of an apparatus according to the invention for exhaust gas treatment. When using the exhaust gas treatment unit 1 in the exhaust system of an internal combustion engine 100, the exhaust gas treatment unit 1 is flowed through by an exhaust gas stream 10 in a flow direction 11. By dividing wall 4 separating flow regions 2, 3, the exhaust gas stream 10 is split into a first partial exhaust gas stream 12 and a second partial exhaust gas stream 13. In the first partial exhaust gas stream 12, which flows through the second flow zone 2, an enrichment is effected by means of the plasma generator 5. of nitric oxide. Before the enrichment in the plasma generator 5, an oxygen and optionally nitrogen-containing gas can be supplied by means of gas supply means 14. This may in particular be air. Due to the contact of the oxygen-containing gas with the common wall 4, the oxygen-containing gas is preheated by the exhaust gas flowing on the other side of the common wall 4. Both exhaust gas and air contain sufficient nitrogen (N2) _» which is available for oxidation to nitrogen oxides (NO _x ), preferably to nitric oxide (NO). After enrichment of the first partial exhaust gas stream 12 with nitrogen monoxide in the second embodiment of an exhaust gas treatment unit 1 in a first honeycomb structure 15, which has a first reduction catalyst coating, the reduction of still contained in the first partial exhaust stream 12 oxygen. The first honeycomb structure 15 can be traversed in the flow direction 11 for an exhaust gas and has in particular corresponding through the first honeycomb structure 15 continuous cavities or channels. The first honeycomb structure 15, like all other honeycomb structures disclosed herein, can be constructed, in particular, as a ceramic monolith or from at least partially structured metallic layers. In the flow direction 11 downstream of the first honeycomb structure 15, a second honeycomb structure 16 is formed. The second honeycomb structure 16 has a second reduction catalyst coating for the reduction of nitrogen monoxide to ammonia. Thus, in the flow direction 11 downstream of the second honeycomb structure 16 there is an ammonia-containing first exhaust gas flow 12.

As a result of the end of the dividing wall 4 located downstream in the flow direction 11, a common third flow region forms downstream of this end

17, in which the first partial exhaust gas stream 12 and the second partial exhaust gas stream 13 are brought together again. In the flow direction 11 upstream of the second honeycomb structure 16, a reducing agent supply 18 is formed. By means of this reducing agent supply 18, it is possible to supply reducing agent, which is required for the reduction of nitrogen monoxide to ammonia in the second honeycomb structure 16. In particular, as a reducing agent here coal _W sour substances, for example, the fuel of the internal combustion engine, are supplied.

Figure 3 shows schematically an exhaust system 19. The exhaust stream 10 of an internal combustion engine 20 flows through the exhaust system 19. The partition

4 separates a first flow region 3 from a second flow region 2.

Here is a division of the exhaust stream 10 into a first partial exhaust stream

12 and a second exhaust gas partial stream 13, which flow through the second flow region 2 and the first flow region 3. The first partial exhaust gas flow 12 passes through a plasma generator 5, in which nitrogen monoxide in the first partial exhaust gas flow

12 is enriched. After leaving the plasma generator 5, the first partial exhaust gas stream 12 flows through a second honeycomb structure 16, in which a reduction of the nitrogen monoxide to ammonia takes place. For this purpose, a hydrocarbon or hydrogen-containing reducing agent, in particular fuel of the internal combustion engine, is added via a reducing agent feed 18. After leaving the first flow region 3, the first ammonia-containing first partial exhaust gas stream 12 mixes in the common third flow region 17 with the second partial exhaust gas stream 13, which has passed through the first flow region 3. The mixture of the two partial exhaust gas streams 12, 13 is promoted by a mixer structure 21, in which there is a mixing of the two partial exhaust gas streams 12,

13 is coming. The mixer structure 21 can be constructed from corresponding metal foils such that on the one hand a transverse flow can take place substantially perpendicular to the flow direction 11 and that further conductive structures are formed which force or convey a transverse flow.

After leaving the mixer structure 21, the exhaust gas stream then flows into a third honeycomb structure 22. This third honeycomb structure 22 is provided with a third reduction catalyst coating which catalyzes a selective catalytic reduction of nitrogen oxides with the reducing agent ammonia. The third honeycomb structure 22 thus leaves a cleaned exhaust gas stream 23 whose nitrogen oxide content is at least substantially reduced compared to the nitrogen oxide content of the exhaust stream 10

Figure 4 shows schematically a second exemplary embodiment of an exhaust system in longitudinal section. In the exhaust system 19, a plasma generator 5 is first formed in a second flow region 2. Downstream in the flow direction 11, behind the plasma generator 5, a first honeycomb structure 15 is formed for the reduction of any residual oxygen still present in the partial exhaust gas flow. Further downstream, a second honeycomb structure 16 is formed, in which a reduction of the nitrogen monoxide produced in the plasma generator 5 to ammonia takes place. Further downstream, means 24 for temporary storage of a reducing agent are formed. This may in particular be ammonia, which is formed in the second honeycomb structure 16. The means 24 for the temporary storage of a reducing agent make it possible to store a portion of the reducing agent in times of a reductant excess and to release it later if necessary. This can be done, for example, by a process based on chemical or physisorption, which can be reversed by supplying heat if necessary.

The plasma generator 5 is connected to control means 25, via which the plasma generator is supplied with power. Furthermore, the exhaust system 19 on Strömungsleitmittel 26, which are formed in the flow direction 11 in front of the partition wall 4 between the first 2 and the second flow region 3. This Strömungsleitmittel 26 as well as all other disclosed herein Strömungsleit- and -leitungsmittel may be formed, for example, as a conduit sheet or as a pivotable flap, which allows a variation of the distribution of the exhaust gas partial streams on the first 2 and the second flow region 3 during operation. The mobility of the flow guide 26 has been indicated by the arrow. FIG. 5 schematically shows a cross section through an exhaust gas treatment unit 1 in a region in which the first flow region 3 and the second flow region 2 are already formed. These are separated by the partition wall 4. In particular, such a heating of a relatively cold gas flowing through the second flow region 2 can take place through a relatively warm gas flowing through the first flow region 3. In this case, the heating of an operating gas for the plasma generator 5 in the second flow region 2 by the exhaust gas flowing through the first flow region 3 of the internal combustion engine 20 is preferred. An exhaust gas treatment unit 1 according to the invention may in particular also comprise a so-called "double-D pipe", which for example consists of two D-shaped deformed tubes, which are optionally held in a common tubular outer tube.

The exhaust gas or gas mass flow flowing through the second flow region 2 is preferably small in comparison with the exhaust gas mass flow flowing through the first flow region 3.

The exhaust gas treatment unit 1 advantageously permits the compact construction of a plasma generator 5 which operates in only a partial flow of the gas flowing through the exhaust gas treatment unit. Particularly advantageous is an exhaust gas treatment unit 1 with a plasma generator 5 for use in an exhaust system 19 in the context of a system or a method for reducing the nitrogen oxide emissions of an internal combustion engine 20. Due to the compact construction of the plasma generator 5, this is particularly suitable for use in exhaust systems 19 of mobile systems such as motor vehicles, especially passenger cars and trucks.

The exhaust gas treatment unit described in FIGS. 1 to 5 and the corresponding other parts of the invention can also be realized in isolation without the remaining parts of the device for exhaust gas aftertreatment. FIG. 6 schematically shows a first exemplary embodiment of a device according to the invention for treating the exhaust gases of an internal combustion engine 100, which comprises a particle separator 101, an SCR catalytic converter 102 for the selective catalytic reduction of nitrogen oxides (NOx) and an ammonia generator 103, the on-board in the ammonia generator generated ammonia is used as a selective reducing agent for the selective catalytic reduction of nitrogen oxides in the SCR catalyst. According to the invention, the particle separator 101 is formed in a main exhaust line 104 and the ammonia generator 103 in a first secondary line 105. The first secondary line 105 opens into the main exhaust line 104 in a junction 106. In the first exemplary embodiment, the junction 106 is formed upstream of the SCR catalytic converter 102.

Upstream of the ammonia generator 103, means 107 for providing at least one operating gas for the ammonia generator 103 are formed. These means 107 may also be included in the ammonia generator 103. The means

107 comprise in particular at least one of the following means: a) means for providing a nitrogen-containing operating gas stream; b) means for providing a hydrogen-containing reducing agent stream; c) means for providing an oxygen-containing operating gas stream.

For the possibilities a) and c) means for supplying exhaust gas, air and / or recirculated exhaust gas may be formed. The agents b) may comprise a reformer which generates a hydrogen-containing operating gas by means of partial oxidation from a hydrocarbon-containing educt.

Downstream of the SCR catalyst 102 may be a first oxidation catalyst

Be formed at which may be oxidized by the SCR catalytic converter 102 breaking ammonia or erupting hydrocarbons and thus are not released to the environment. 7 schematically shows a second exemplary embodiment of a device according to the invention for treating the exhaust gas of an internal combustion engine 100. In a main exhaust line 104, a first catalytic converter 108 is formed in a main exhaust line 101, an SCR catalytic converter 102 and downstream of the SCR catalytic converter 102. In particular, SCR catalyst 102 and first oxidation catalyst 108 may be formed on a single honeycomb body.

In the first secondary line 105, an ammonia generator 103 comprising a plasma generator 114 is formed. This is supplied via a compressor 109 with air as operating gas. Furthermore, in the second embodiment, a second secondary line 110 is formed, which comprises a reformer 111. This is connected to a fuel tank 112, from which the reformer 111 is supplied with hydrocarbons. Furthermore, the reformer 111 is supplied with an oxygen-containing gas, for example, air or the exhaust gas recirculation line exhaust gas removed. In the reformer 111, a partial oxidation of the hydrocarbons, so that a hydrogen-containing synthesis and / or fission gas stream is formed, which can be fed via the second junction 113 in the first secondary strand 105.

The plasma generator 114 generates a nitrogen oxide-containing, preferably nitrogen monoxide-containing, gas stream which is temporarily stored in the storage / reduction element 115. Chemisorption, in which the nitrogen oxides are stored in the form of nitrates and / or nitrites, is preferred here. Here, the nitrites and nitrates can react by means of hydrogen to form ammonia. The storage / reduction element 115 then leaves an ammonia-containing gas stream which first flows through the particle separator 101 and subsequently through the SCR catalytic converter 102. In the SCR catalyst 102, the ammonia acts as a reducing agent for the selective reduction of nitrogen oxides, in the particle separator 101 it can serve as an inhibitor for the regeneration of the particulate filter. Figure 8 shows schematically a section of a device according to the invention. In the main exhaust line 104, the particle separator 101 is formed. This comprises means 116 for generating a surface sliding discharge as a regeneration possibility of the particle separator 101.

Figure 9 shows schematically a section of a device according to the invention. In the main exhaust line 104, a particle separator 101 is formed. Upstream, ie in the direction of the internal combustion engine 100, a second oxidation catalyst 117 is formed. This can serve as a means of both the thermal regeneration and the chemical regeneration of the Partikelabscheiders 101. In the case of the chemical regeneration possibilities 10.1) and / or 10.3), the second oxidation catalyst 117 can serve for the oxidation of nitrogen monoxide to nitrogen dioxide, which can serve as a regeneration agent of the particle separator, in particular in the context of a CRT process. In the case of a thermal regeneration option 10.2) of the particle separator 101, hydrocarbons can be applied to the second oxidation catalyst 117 through the feed line 118, which are converted there and due to the exothermic oxidation of the hydrocarbons, a heating of the gas stream flowing through the particle separator 101 takes place. The second oxidation catalytic converter 117 may in particular also be part of the particle separator 101. The particle separator 101 can in particular also be equipped with an alternative or additional resistance heater or, for example, in its gas inlet-side, the internal combustion engine 100 facing region comprising a heated disc.

10 shows schematically a third exemplary embodiment of an inventive device for processing the exhaust gas of an internal combustion engine 100. The exhaust system comprises a main exhaust line 104 and a second secondary line 110, which branches off from the main exhaust line 104 upstream of a turbocharger 119. In the second secondary line 110, a reformer 111 is formed. det. The second secondary line 110 branches off in the branch 120 from the main line 104. The branch 120 is formed upstream of the turbocharger 119, while the second junction 113 is formed downstream of the turbocharger 119.

Furthermore, a first secondary line 105 is formed, in which an ammonia generator 103 comprising a plasma generator 114 is formed. As the operating gas 121 for the plasma generator 114 air and / or exhaust gas is used here, wherein the operating gas 121 may include exhaust gas and / or air. The operating gas 121 can be heated, in particular by waste heat of the exhaust gas of the internal combustion engine and / or by an electrical resistance heater 122.

In operation, the plasma generator 114 converts nitrogen and oxygen from the operating gas 121 to nitrogen oxides, preferably to nitric oxide. The plasma generator 121 is operated so that the highest possible yield of nitrogen monoxide is achieved. The nitrogen oxide-containing gas stream is then passed through the storage / reduction element 115, in which the nitrogen oxides, preferably nitrogen monoxide, chemisorbed and stored as nitrite and / or nitrate.

If the storage / reduction element 115 is now flowed through by the hydrogen-containing gas generated in the reformer 111, the nitrites and / or nitrates are reduced to ammonia. The resulting ammonia-containing gas stream is then passed through the SCR catalyst 102 and used there as a selective reducing agent for nitrogen oxides. The SCR catalyst 102 preferably comprises a honeycomb body as described above.

In the main exhaust line 104, a second oxidation catalyst 117 is formed, in which preferably an oxidation of nitrogen monoxide is catalyzed to nitrogen dioxide. This nitrogen dioxide (NO2) then converts carbon (C) contained in the particles into carbon dioxide (CO2) and becomes nitrogen itself. reduced monoxide (NO). This allows a regeneration of the Partikelabschei- DSRs 101 SUC ^g s.

In addition to at least one filter element 123, the particle separator 101 may advantageously contain a second plasma generator 124, which cooperates with the at least one filter element 123 and is designed and operated such that electrical surface sliding discharges trigger the regeneration of the filter elements. With regard to the design and operation of the plasma generator, reference is made to DE 100 57 862 C1, the disclosure content of which is included in so far in the disclosure of this invention.

Furthermore, a control unit 125 is formed, which is connectable to a voltage source 126. This control unit 125 controls the plasma generator 114 and the second plasma generator 124 together. In this case, data from a motor controller 127 can be taken into account. In particular, based on the data of the engine controller 127, preferably based on the engine map, the NOx concentration in the exhaust gas can be determined.

The at least one filter element 123, the second oxidation catalytic converter 117, the SCR catalytic converter 102, the reformer 111, the storage / reduction unit 115, the ammonia generator 103 and / or the particle separator 101 may comprise at least one honeycomb body. The components of the device may preferably be formed in a common housing 128.

FIG. 11 schematically shows an ammonia generator 103, which is formed in the first secondary line 105. This comprises a plasma generator 114 in which nitrogen oxides, preferably nitrogen monoxide, are produced from a starting material mixture comprising nitrogen and oxygen. The gas stream thus produced nitrogen monoxide is passed into a first gas train 129 or a second gas train 130. The first gas train 129 comprises a first The second gas train 130 has a second storage / reduction element 132. In the gas train 129, 130 through which the exhaust gas of the plasma generator 114 flows, chemisorption of the nitrogen oxides takes place on the corresponding storage / reduction element 131, 132. The storage takes place as nitrite and / or nitrate. In the respective other gas line 130, 129, a reduction and simultaneous conversion of the respective nitrite and / or nitrate groups to ammonia takes place by passing a hydrogen-containing gas stream produced by the reactor 133. The ammonia-containing gas stream thus obtained is passed into the main exhaust line 104 to be used in the downstream SCR catalyst 102 as a selective reducing agent for the reduction of nitrogen oxides. The reactor 133 may in particular comprise a reformer and / or generate hydrogen by partial oxidation of hydrocarbons.

By the intermittent operation of the plasma generator 114, in each of which a storage / reduction element 131, 132 filled and parallel the other storage / reduction element 131, 132 is emptied, the required amount of hydrogen is reduced, since it is possible in the emptying the storage / reduction elements 131, 132 to keep the existing oxygen content as low as possible. In this case, there is no hydrogen-consuming reaction between hydrogen and oxygen, but predominantly to the desired reduction of the nitrates / nitrites to ammonia. The gas flows can be controlled by valves 134 accordingly.

FIG. 12 shows an advantageous development, in which the particle separator 101 comprises at least two elements 136 which can be connected to means 135 for generating a first electric field. The first electric field can be used to agglomerate and / or separate the particles.

The method according to the invention and the device according to the invention make it possible in an advantageous manner to reduce the proportion of exhaust gas in an internal combustion engine. machine 100 contained particles and nitrogen oxides (NO _x ) at the same time to reduce, the power consumption for this reduction is low and at the same time the entire device is designed as a compact unit buildable.

LIST OF REFERENCE NUMBERS

1 exhaust treatment unit

2 second flow region 3 first flow region

4 common wall

5 plasma generator

6 first electrode

7 second electrode 8 plasma channel

9 connection

10 exhaust gas flow

11 flow direction

12 first partial exhaust gas flow 13 second partial exhaust gas flow

14 gas circulation means

15 first honeycomb structure

16 second honeycomb structure

17 third flow area 18 reduction feed means

19 exhaust system

20 internal combustion engine

21 mixer structure

22 third honeycomb structure 23 purified exhaust gas stream

24 means for temporary storage of a reducing agent

25 control means

26 flow guide

100 Internal combustion engine 101 Particle separator

102 SCR catalyst 103 ammonia generator

104 main exhaust line

105 first secondary strand

106 confluence 107 means for providing at least one operating gas

108 first oxidation catalyst

109 compressor

110 second secondary strand

111 reformer 112 fuel tank

113 second junction

114 plasma generator

115 storage / reduction element

116 means for generating a surface sliding discharge 117 second oxidation catalyst

118 supply line

119 turbocharger

120 diversion

121 operating gas 122 resistance heating

123 filter element

124 second plasma generator

125 control unit

126 Voltage source 127 Motor control

128 housing

129 first gas train

130 second gas train

131 first storage / reduction element 132 second storage / reduction element

133 reactor 134 valve

135 means for generating a first electric field

Claims

claims

A device for exhaust gas treatment, comprising - a particle separator (101),

- An SCR catalyst (102) for the selective reduction of nitrogen oxides and

- An ammonia generator (103) for generating ammonia as a selective reducing agent for the reduction of nitrogen oxides, wherein the Partikelabscheider (101) in a main exhaust line (104) and the ammonia generator (103) in a first secondary line (105) is formed, wherein the first Nebenstrang (105) opens into an exit in the main exhaust line (104), which is designed so that the Arnmoniakhaltige gas flow generated in the ammonia generator (103) can flow through the SCR catalyst (102).

2. Device according to claim 1, wherein the first secondary line (105) in a first junction (106) opens into the main exhaust line, which is designed so that the ammonia-containing gas stream generated in the ammonia generator (103) can also flow through the particle separator (101) ,

3. Device according to one of the preceding claims, wherein the particle separator (101) has a regeneration option for the regeneration of the Partikelabscheiders (101).

4. The apparatus of claim 3, wherein the particle separator (101) is formed and / or such means (116, 117, 124) are provided that the regeneration capability is generated by at least one of the following measures: 10.1) providing nitrogen dioxide upstream at least one

Part of the particle separator (101);

10.2) raising the temperature of at least part of the particle separator (1 oil) above a limit temperature;

10.3) providing an oxidant upstream of at least a portion of the particle separator (101); or 10.4) regeneration by an electrical discharge.

5. Apparatus according to claim 4, wherein means (116) for regeneration are provided by a surface sliding discharge.

6. Device according to one of the preceding claims, wherein the Partikelabscheider (101) comprises means (135) for generating a first electric field in the particle separator (101) through which at least one of the following functions is fulfilled: 12.1) agglomeration of particles; or 12.2) Separation of particles.

7. Device according to one of the preceding claims, wherein the particle separator (101) comprises means (116) for generating a second electric field in the particle separator (101), by means of which a Oberfläch- chengengleitentladung is generated for regeneration.

8. Device according to one of the preceding claims, wherein the ammonia generator (103) comprises a plasma generator (5, 114).

9. Device according to one of the preceding claims, wherein the ammonia generator (103) at least one storage element (115, 131, 132) for temporarily storing at least one of the following components: 15.1) ammonia or 15.2) an ammonia precursor.

10. The apparatus of claim 9, wherein the component 15.2) Stickstoffmo ^¬ comprises monoxide.

11. Device according to one of the preceding claims, wherein the first secondary strand (105) is flowed through by at least one of the following gases:

24.1) exhaust gas;

24.2) a gas comprising at least oxygen and nitrogen; or

24.3) air.

12. Device according to one of the preceding claims, wherein at least one of the following points, an oxidation catalyst (108, 117) is formed:

26.1) upstream of the particle separator (101); 26.2) downstream of the ammonia generator (103) and upstream of the ammonia generator (103)

SCR catalyst (102); or 26.3) downstream of the SCR catalyst (102).

13. Device according to one of the preceding claims, comprising a first flow region (3) and at least one second flow region (2), which are flowed through substantially parallel to each other, wherein the first flow region (3) is at least a part of the main exhaust line (104), wherein the first (3) and the second flow region (2) are formed such that a heat input from the first flow region (3) into the at least one second flow region (2) can take place.

14. The device according to claim 13, wherein at least one of the following components is formed in a second flow region (2): 31.1) at least one plasma generator (5, 114), 31.2) at least one reformer (111) or

31.3) at least one reactor (133).

15. A method for treating exhaust gas, in which by a particle separator (101) located in the exhaust particles are at least partially separated and are at least partially reduced in the nitrogen oxides in the exhaust gas in an SCR catalyst (102), wherein the deposition of the particles in a Main exhaust line (104) takes place and in a first secondary line (105) ammonia is generated, which is the SCR catalyst (102) supplied as a reducing agent.

16. The method of claim 15, wherein the first secondary line (105) and the main exhaust line (104) are merged so that the ammonia-containing gas stream generated in the first secondary line (105) can flow through the particle separator (101).

17. The method according to any one of claims 15 or 16, wherein in the Partikelabscheider (101) at least one electric field is formed, which fulfills at least one of the following functions:

58.1) agglomeration of the particles,

58.2) separation of the particles or 58.3) regeneration of the particle separator (101).

18. The method according to any one of claims 15 to 17, wherein the particle separator (101) has a regeneration possibility for the regeneration of the Partikelabscheiders (101).

19. The method of claim 18, wherein the regeneration capability is based on at least one of the following mechanisms:

60.1) providing at least one nitrogen dioxide upstream

Part of the particle separator (101); 60.2) raising the temperature of at least part of the particle separator (101) above a limit temperature;

60.3) providing an oxidant upstream of at least a portion of the particle separator (101); or

60.4) Regeneration by an electrical discharge.

20. The method of claim 19, wherein the regeneration option according to 60.4) comprises a surface sliding discharge.

21. The method according to any one of claims 15 to 20, wherein the ammonia (NH3) is generated by a plasma-assisted generation of nitrogen monoxide and subsequent reduction to ammonia.

22. The method of claim 21, wherein a plasma generator is operated with a nitrogen and oxygen-containing first operating gas.

23. The method according to any one of claims 15 to 22, wherein the ammonia (NH3) is generated in an ammonia generator (103) and the ammonia generator (103) preferably at least one storage element (131, 132), in which nitrogen oxides (NO _x ) reversibly storable.

24. The method according to any one of claims 15 to 23, wherein the ammonia production in dependence on the NO _x - and / or the ammonia concentration in the exhaust gas regulated and / or controlled.

25. The method of claim 24, wherein a NO _x - and / or an ammonia content of the exhaust gas is detected by a sensor.

26. The method of claim 24 or 25, wherein the NOx concentration from the operating data of the internal combustion engine (20, 100) is determined.