WO2001085311A1

WO2001085311A1 - Method and device for the catalytic conversion of a substance

Info

Publication number: WO2001085311A1
Application number: PCT/DE2001/001782
Authority: WO
Inventors: Erich Hums; Horst Spielmann
Original assignee: Siemens Aktiengesellschaft
Priority date: 2000-05-10
Filing date: 2001-05-10
Publication date: 2001-11-15
Also published as: EP1296751A1; TW561144B; CN1240467C; CN1429129A; KR20030015236A; DE10022763A1

Abstract

The invention relates to a method for converting a substance contained in a gas stream (A). According to said method, the gas stream (A) is supplied to a reaction chamber (2) and the substance (NO) is subjected to the action of a catalytically active material (K, KU). A material (S) which is a catalytically active material (K; KU), or from which catalytically active material (K; KU) can be formed, is supplied to the reaction chamber (2) together with the gas stream (A). The material (S) is preferably mixed with a combustible (B). When the latter is burnt, the substance (NO) contained in the gas stream (A) is produced as exhaust gas. According to a method for reactivating a deactivated catalyst module (3), the catalyst module (3) is wetted by a material (S), which is, or contains a fresh, catalytically active material (KU), or from which such a material can be separated. The two methods can be used in particular, in accordance with the principle of selective catalytic reduction, for the degradation of nitrogen oxide (NO) in a combustion gas (A). The invention also relates to a combustible (B), which contains a material (S) that is a catalytically active material, or from which catalytically active material (KU) is produced during combustion.

Description

description

Method and device for the catalytic conversion of a substance

The invention is in the field of catalysts.

The invention relates to a method for converting a substance in a gas stream, in particular for the catalytic conversion of nitrogen oxide into one mixed with ammonia

Flue gas flow to water and nitrogen according to the principle of selective catalytic reduction, the gas flow being fed to a reaction space and the substance being exposed to the action of a catalytically active material.

The invention also relates to a method for reactivating an at least partially deactivated catalyst module which has been produced by depositing a catalytically active material in or on a catalyst substrate, in particular for reactivating a catalyst module which works on the principle of selective catalytic reduction for the reduction of nitrogen oxide in a flue gas.

The invention also relates to a fuel for combustion in a combustion process.

Furthermore, the invention relates to an exhaust gas purification system of the first type, in particular for a combustion system of a power plant or for an internal combustion engine of a motor vehicle, in which an exhaust gas stream resulting from the combustion is passed through a catalytic converter module to convert a pollutant contained therein by separating a the catalytic conversion of the pollutant-promoting catalytically active material is produced on or in a catalyst substrate, it being possible in particular to convert nitrogen oxide contained in the exhaust gas stream according to the principle of selective catalytic reduction. The invention also relates to an exhaust gas purification system of the second type, in particular for a combustion system of a power plant or an internal combustion engine of a motor vehicle, in which an exhaust gas stream resulting from the combustion of a fuel for converting a pollutant contained therein is passed through a catalyst module which is separated by separating the catalytic conversion of the pollutant-demanding catalytically active material is produced on or in a catalyst substrate, wherein in particular nitrogen oxide contained in the exhaust gas stream can be converted according to the principle of selective catalytic reduction.

The oxidic combustion of fossil fuels creates substances or pollutants in the exhaust gas or flue gas that pollute the environment. For example, nitrogen oxides, for example NO or NO ₂ , are contained in the flue gases which arise in waste incineration plants, power plants, melting furnaces or heating plants. An exhaust gas or fluid flow of a comparable type also arises when diesel fuel or other fuels are burned in the internal combustion engines of motor vehicles.

A process known as "selective catalytic reduction (SCR)" for converting the undesired nitrogen oxides is described, for example, in a brochure from Siemens AG with the

Order number A96001-U11-A294-V1 from 1996, or known from German patent DE 24 58 888.

In this process, nitrogen oxides are converted catalytically into harmless nitrogen and water vapor by adding ammonia. For this purpose, the flue gas or exhaust gas is passed through a catalytic converter or through a catalytic converter module at a temperature between 300 and 500 ° C. The catalyst module consists of a ceramic matrix or a ceramic catalyst substrate, on which a catalytically active material is deposited, which effects or promotes the conversion of the nitrogen oxides into nitrogen and water vapor. On such catalytic material are, for example, the oxides of titanium, vanadium and / or tungsten and / or molybdenum.

It is known that SCR catalysts deactivate in the course of their operation, depending on the smoke gas constituents. The reasons for the deactivation are e.g. chemically justified, i.e. that the catalytically active material forms compounds that cannot participate in the SCR process. However, it may also be the case that the catalytically active material is transported out of the catalytic converter module by the exhaust gas stream flowing through during operation. This occurs in particular if the catalytically active material enters into volatile metal-halogen compounds with halogens contained in the exhaust gas.

The deactivation of the SCR catalysts has been compensated so far by adding additional catalyst volume or additional catalyst modules. This procedure is expensive and complex. When performing the ^' SCR in

It is technically feasible in the motor vehicle sector only with unacceptable effort. A power plant shutdown is required for use in the power plant area.

Accordingly, there is a need to counteract the deactivation of the catalytically active material by other measures. The invention is therefore based on the object of specifying a method, a device and a substance for this purpose.

This object is achieved in relation to the method according to the invention mentioned at the outset in that a substance which is catalytically active material or from which catalytically active material can be formed is fed to the reaction space with the gas stream. The substance is preferably added continuously. However, discontinuous addition is also possible.

A catalyst module is not necessarily required when performing this method. The catalytic conversion of the pollutant in the exhaust gas can take place solely through such catalytically active material that is fed to the reaction space in the form of the substance. This catalytically active material can be fed continuously or batchwise.

According to a preferred embodiment, the gas stream is passed through a catalyst substra, in particular arranged in the reaction space, or past one.

The substance is preferably added to the gas stream in the flow direction upstream of the catalyst substrate.

In particular, the substance is highly dispersed or atomized when added to the gas stream.

The substance is preferably or is admixed with a fuel, the combustion of which produces the substance contained in the gas stream as exhaust gas.

A catalytically active material which promotes the catalytic conversion of the substance is incorporated or deposited to form a catalyst module with particular advantage in or on the catalyst substrate. The catalyst module was thus produced, for example, by separating the catalytically active material in a separate manufacturing process before carrying out the method according to the invention.

If such a catalyst module is completely or partially deactivated, it is possible with this method to regenerate it quasi in situ. The catalyst module therefore does not necessarily have to be taken out of operation for regeneration. that, in particular a power plant does not necessarily have to go out of operation. In the case of a fresh or unused catalyst module, deactivation is counteracted right from the start when this method is used.

According to a preferred embodiment, the catalytically active material which is supplied with the gas stream or is formed from the substance is the same as the catalytically active material which was incorporated or deposited in the manufacture of the catalyst module. This regenerates the catalytic converter module in a particularly efficient manner.

In addition, the catalytic material added to or formed in the gas stream itself has a catalytic effect, so that an increase in the catalytic efficiency would be possible even if the catalyst module were not regenerated.

To increase the regeneration effect, the catalytically active material added upstream of the catalyst module or the catalytically active material formed from the substance has the property of being deposited on the catalyst module.

A catalyst module is likewise formed with particular advantage by incorporating or depositing the catalytically active material of the gas stream in or on the catalyst substrate.

With this method it is namely possible in a particularly advantageous manner to introduce an inert or catalytically inactive catalyst substrate into the gas stream. The catalyst module then gradually forms by separating or storing the catalytically active material formed from or contained in the substance.

The catalyst module is produced in particular in the following steps: a) The gas stream is mixed with a substance which is or contains catalytically active material or from which catalytically active material can be separated. b) The gas stream is then passed through or over a catalyst substrate. c) The catalyst module is formed by depositing or embedding the catalytically active material on or in the catalyst substrate.

The process-related object is achieved in relation to the method mentioned at the outset according to the invention in that the catalyst module is wetted with a substance which is or contains catalytically active material or from which catalytically active material can be separated.

For example, after the catalyst module has been in operation for a long time, catalytic material is again applied or introduced into or onto the catalyst substrate of the catalyst module.

In particular, the catalytically active material of the substance is stored and / or deposited in or on the catalytically active material which is present due to the production.

The catalytically active material of the substance is particularly advantageously the same as the catalytically active material that was deposited or deposited during the manufacture of the catalyst module.

According to a particularly preferred embodiment, the substance is fed to the catalyst module during catalyst operation. Such online operation has the particular advantage that the catalyst module does not have to be taken out of operation for the regeneration and therefore there is no need to interrupt the catalytically influenced process. The substance is preferably mixed with a substance which is fed to the catalyst module to promote the conversion of the substance. It is therefore advantageously not necessary to have a separate material flow to the catalyst module, since the substance is admixed with the substance that is supplied to the catalyst module anyway in accordance with the operation.

For wetting the catalyst module, the substance is preferably in the vaporized or gaseous state.

According to a preferred variant, the substance is or is mixed with a fuel, the combustion of which produces a substance as exhaust gas, which is fed to the catalyst module to promote the conversion of the substance.

In all of the processes mentioned, the catalytically active material preferably contains atoms of one of the elements vanadium, titanium, tungsten, iron and / or molybdenum, and the catalytically active material is in particular an oxide of one of these metals. Mixtures of the elements mentioned are also possible.

The related to a material object is .gemäß of the invention characterized by ^'' a fuel for combustion in a combustion process, which contains a substance or a substance is added, the catalytically active material or is selected from the catalytically active material in the combustion arises. The fuel thus contains, in particular, catalytically active material or catalytically active material is added to it.

Such a fuel is particularly suitable for carrying out the method according to the invention, in particular for those configurations in which a fuel is explicitly used. The advantages mentioned in this connection apply analogously to the fuel. The substance content in the fuel preferably has a value between 10 mg / kg of fuel and 200 mg / kg of fuel.

In particular, the catalytic material content of the fuel has a value between 50 mg / kg fuel and 100 mg / kg fuel.

The substance, and in particular the catalytically active material, is preferably contained in the fuel in dissolved or dispersed form or is added to it in soluble or dispersing form.

The catalytically active material is preferably suitable for promoting the conversion of the pollutant formed during the combustion.

According to a particularly preferred embodiment, the catalytically active material has the property of converting nitrogen oxide according to the principle of selective catalytic reduction, which is contained in the exhaust gas produced during the combustion.

According to another preferred embodiment of the fuel, the catalytically active material contains at least one of the elements vanadium, titanium, tungsten, iron, molybdenum, or mixtures thereof.

The device-related object is achieved in relation to the exhaust gas purification system of the first type mentioned at the outset according to the invention by an injection device with which a substance can be fed into the exhaust gas in the flow direction upstream of the catalyst module, the substance being or containing catalytically active material or from the substance being catalytically active Material is separable.

The injection device preferably has a storage container for holding the substance. The device-related object is achieved in relation to the exhaust gas cleaning system of the second type mentioned at the outset according to the invention by means of a feed device by means of which a substance can be added to the fuel, the substance being or containing or containing catalytically active material or being able to be separated from the substance.

The exhaust gas cleaning systems of both types are particularly suitable for carrying out the first-mentioned method according to the invention. The advantages mentioned in connection with this apply analogously to these emission control systems.

The feed device preferably has a storage container for holding the substance.

Six exemplary embodiments of a device according to the invention or to explain a method according to the invention are explained in more detail below with reference to FIGS. 1 to 6. Show it:

1 shows a first exemplary embodiment of an exhaust gas cleaning system according to the invention,

2 shows a second embodiment relating to

Implementation of a method according to the invention,

3 shows a third exemplary embodiment relating to a method according to the invention,

4 shows a fourth exemplary embodiment relating to a method according to the invention,

IG 5 a fifth exemplary embodiment relating to a method according to the invention, FIG. 6 shows a sixth exemplary embodiment relating to an apparatus and a method according to the invention,

7 shows a first measurement result, which was achieved with the method according to the second embodiment, and

8 shows a second measurement result which was achieved with the method of the second exemplary embodiment.

FIG. 1 shows a line 1 in which a reaction space 2 is formed. A catalyst device comprising three catalyst modules 3 is arranged in the reaction space 2. A fluid or gas A, which is an exhaust gas or flue gas, flows through the catalyst modules 3 in the flow direction 5. The exhaust gas A contains a substance or pollutant, namely nitrogen oxide NO (NO _x ). In order to reduce the nitrogen oxides according to the principle of selective catalytic reduction (SCR), ammonia NH (NH ₃ ) reducing agent is added to the gas A with the pollutant NO by means of a first feed line 7 opening into the line 1. The nitrogen oxides NO, together with the admixed ammonia NH, enter the catalyst modules 3 in the reaction space 2, where the nitrogen oxide NO is converted into nitrogen (N ₂ ) and water vapor (H ₂ 0), so that the exiting after the catalyst modules 3 Gas stream has a greatly reduced nitrogen oxide content.

The exhaust gas A originates, for example, from the combustion system of a power plant operated with gas, oil or coal. The catalyst modules 3 contain K as a catalytically active material, vanadium, molybdenum, tungsten and / or titanium, in particular in oxidic form. In the preferred temperature range of 300 ° C to 450 ° C, the catalytically active materials K used for the SCR process work highly selectively, so that undesirable side reactions are largely prevented.

The catalyst modules 3 can partially or completely deactivate after prolonged operation. The effects of dust or come as possible causes of deactivation the action of chemical compounds, for example halogens contained in the exhaust gas A, on the catalytically active material K into question.

For in-situ regeneration of the deactivated catalyst modules 3, new or fresh catalytically active material KU is fed to the exhaust gas A in the flow direction 5 upstream of the catalyst modules 3 by means of an injection device 8. Instead of catalytically active material KU, the injection device 8 can also be used to supply a substance S from which the catalytically active material KU is formed, for example only in the exhaust gas stream A. The added or forming catalytically active material KU is the same or has a similar composition to the catalytically active material K that is already present in the catalyst modules 3 or was originally present.

The injection device 8 has a storage container 11 for holding the substance S or the catalytically active material KU. Starting from the storage container 11, a second feed line 9 opens into the line 1 carrying the exhaust gas A. The second feed line 9 is configured at its mouth in such a way that the substance S or the catalytically active material KU disperses or enters the line 1 is atomized.

The line 1, the catalyst modules 3 and the first feed line 7, together with the injection device 8, form an exhaust gas cleaning system 13 which can be used both stationary for a combustion system of a power plant and for a combustion engine of a motor vehicle.

The second exemplary embodiment of a method according to the invention shown in FIG. 2 differs from the first exemplary embodiment essentially in that the

Substance S or the fresh catalytically active material KU is mixed with a fuel B, from which voltage in a combustion chamber 15, the exhaust gas A only arises. In the exemplary embodiment shown, the fuel B, to which the substance S or the catalytically active material KU is added in dissolved or dispersed form, is conveyed into the combustion chamber 15 by means of a fuel line 17. A pump 19 is provided to deliver the fuel B from a tank 21. The fuel B contains the substance S or the catalytically active material KU with a proportion between 10 mg / kg fuel and 200 mg / kg fuel.

The fuel B is burned in the combustion chamber 15, producing nitrogen oxide-containing exhaust gas A. For example, the new catalytically active material KU also forms from the substance S in the combustion chamber 15. The exhaust gas A with the nitrogen oxide NO and the new catalytically active material KU comes out of the combustion chamber 15 through the line 1 to the catalyst modules 3 in the reaction space 2. In the flow direction 5 in front of the catalyst modules 3, the first feed line is used, as in the first exemplary embodiment 7 ammonia NH mixed.

The catalyst modules 3 are regenerated by the combustion of the fuel B mixed with substance S or catalytically active material KU for a longer period of time.

This regeneration can be seen from the first measurement result shown in FIG. In the underlying experiment, catalytic material KU was added to the fuel B of a refinery power plant as a mixture of vanadium V and iron Fe. 102 mg vanadium and 252 mg Eis.en per kg fuel B were added. During the combustion of fuel B, an exhaust gas flow with a volume flow iN moist of 150,000 m ³ / h was generated. The vanadium content in exhaust gas A or flue gas was 316 ppm. A damp smoke density of 1.31 kg / m ^{3 was used as a} basis. The operating temperature of the catalyst modules 3 was 370 ° C. The table below shows the vanadium content V205 (content of vanadium oxide V ₂ 0 ₅ ) at the start of the combustion of fuel B (t = Oh) and after approx. 6000 h, in each case measured on the upstream and downstream sides of the catalyst modules 3:

In the diagram in FIG. 7, the vanadium content V205 in the catalyst modules 3 is plotted in percent on the left ordinate. The time t in hours (h) is plotted on the abscissa.

The vanadium content V205 in the partially deactivated catalyst modules 3 was approximately 0.4% at the start of the regeneration measure (t = 0h). After 6000 hours of operation, the vanadium content V205 was measured with XRF (= X-ray fluorescence analysis), a dust covering having been removed beforehand.

The diagram shows that the vanadium content V205 had risen to about 1.3%. As a result, the nitrogen oxide-specific catalytic activity K-NOx of the catalyst modules 3 rose from initially approximately 41.5 m / h to approximately 48.5 m / h after 6000 operating hours (right ordinate).

In FIG. 8 the oxidation rate K-SOx for the oxidation reaction from S0 ₂ to S0 _{3 is} plotted on the right ordinate. During the 6000-hour observation phase, this increased from initially 200 m / h to approx. 550 m / h.

The third exemplary embodiment shown in FIG. 3 differs from the second ^exemplary embodiment shown in FIG. 2 in that the substance S or the fresh catalytically active material KU is not already mixed into the fuel B in the tank 21, but is only mixed into the fuel B from a separate container 25 after it has been conveyed out of the tank 21. In the example shown, the substance S or the catalytically active material KU is fed from the container 25 to the fuel line 17 by means of a feed line 27, so that the fuel B mixed with the substance S or the fresh catalytically active material KU - as in the exemplary embodiment of Figure 2 - gets into the combustion chamber 15. This variant of supplying fuel to the combustion chamber 15 can also be implemented in the exemplary embodiment in FIG. 2. The container 25 and the feed line 27 form a feed device 28.

The exemplary embodiment in FIG. 3 also differs from the exemplary embodiment in FIG. 2 in that no catalyst modules 3 are present. The catalytic conversion of the nitrogen oxides NO produced during the combustion in the exhaust gas stream A is done in this embodiment by the action al ^¬ lein of the fuel admixed B ka ^¬ catalytically active material KU on the nitrogen oxides NO, in particular in the reaction space. 2

The fourth exemplary embodiment of a method according to the invention shown in FIG. 4 serves to reactivate an at least partially deactivated catalyst module 3. The reactivation takes place ex-situ in the example shown, i.e. in a state in which the catalyst modules 3 are not used for the catalytic conversion of the substance NO.

The deactivated catalyst modules 3 are arranged in this Reakti ^¬ onsraum 2 and are wetted with a substance S, the new or fresh catalytically active material KU is or contains or can be separated from such a catalytically active material KU. The fresh catalytically effective

KU material superimposed here in or on a Katalysa ^¬ torsubstrat 31 on or off, in or on the already during the Production of the catalyst modules 3 catalytically active material K was deposited or deposited. The catalyst modules 3 are regenerated in this way.

In the fifth exemplary embodiment shown in FIG. 5, an initially inert catalyst substrate 33 is assumed. This catalyst substrate 33 is acted upon by a gas stream or exhaust gas stream A which arises, for example, when a fuel is burned. The gas flow A is either in a manner analogous to FIGS. 2 or 3 (in FIG

5 not explicitly shown) or by means of a branch line 29 opening into the line 1, a substance S is added which is or contains catalytically active material K or from which catalytically active material K can be formed. According to the exemplary embodiment shown in FIG. 5, a catalyst module 3 is thus produced by introducing the inert catalyst substrate 33 into the line 1 through which the exhaust gas A flows.

The exhaust gas purification system 41 shown in FIG. 6 as the sixth exemplary embodiment comprises, like the third exemplary embodiment shown in FIG. 3, a feed device 28. In contrast to FIG. 3, however, in FIG

6 shown embodiment, as in the embodiment of Figure 2, catalyst modules 3 are present in the reaction chamber 2, which have been produced by depositing or depositing a catalytically active material K in or on a catalyst substrate 31. In the exemplary embodiment shown in FIG. 6, the catalyst modules 3 are therefore regenerated by means of the new or fresh catalytically active material KU added by the feed device 28, or by means of the substance S, “in situ” or “online”.

A downstream of the capacitor modules 3 in the flow direction 5 is a separating device 49, in which catalytic converter 3 which is not required for regeneration of the catalyst modules effective material KU, that is, 'which is still contained in the exhaust gas stream A after the catalyst modules 3, is separated. A return line 51 leads from the separating device 49 - possibly via a concentrating device (not shown) - to the feed device 28. In this way, catalytically active material KU that is fed in but not required can be used again for feeding into the fuel B. As a result, the costs for catalytically active material KU are considerably reduced.

Claims

claims

1. Process for converting a substance (NO) in a gas stream (A), in particular for the catalytic conversion of nitrogen oxide in a flue gas stream mixed with ammonia (NH) to water and nitrogen according to the principle of selective catalytic reduction, the gas stream (A) fed to a reaction chamber (2) and the substance (NO) being exposed to the action of a catalytically active material (K, KU), characterized in that a substance (S) is fed to the reaction chamber (2) with the gas stream (A) , which is catalytically active material (K; KU) or can be formed from the catalytically active material (K; KU) (Figures 1, 2, 3, 5, 6).

2. The method according to claim 1, which also means that the gas stream (A) is passed through or past a catalyst substrate (31; 33), in particular arranged in the reaction chamber (2).

3. The method as claimed in claim 2, so that the substance (S) is added to the gas stream (A) in the direction of flow (5) upstream of the catalyst substrate (31; 33) (FIGS. 1, 5).

4. The method according to claim 3, so that the substance (S) is homogeneously dispersed or atomized when added to the gas stream (A).

5. The method according to any one of claims 1 to 4, characterized in that the substance (S) is or is mixed with a fuel (B), the combustion of which in the gas stream (A) contains substance (NO) as exhaust gas (Figures 2 or 3, 6).

6. The method according to any one of claims 2 to 5, characterized in that in or on the catalyst substrate (31) a catalytic conversion of the substance (NO) promoting catalytically active material (K) forming or forming a catalyst module (3) is (Figures 1, 2).

7. The method according to claim 6, characterized in that the catalytically active material (KU) which is supplied with the gas stream (A) or formed from the substance (S) is the same as the catalytically active material (K) , which was stored or deposited in the manufacture of the catalyst module (3).

8.- Method according to one of claims 2 to 5, characterized in that a catalyst module (3) is formed by storing or depositing the catalytically active material (K) of the gas stream (A) in or on the catalyst substrate (33) (Figure 5).

9. Procedure _. for reactivating an at least partially deactivated catalyst module (3) which has been produced by depositing a catalytically active material (K) in or on a catalyst substrate (31), in particular for reactivating a catalyst module (3 ) for the decomposition of nitrogen oxide (NO) in a flue gas (A), characterized in that the catalyst module (3) is wetted with a substance (S) that is or contains catalytically active material (KU) or from the catalytically active material (KU) can be separated (Figures 1, 2, 4).

10. The method according to claim 9, characterized in that the kata ^¬ lytically active material (KU) of the substance (S) in or on the catalytically active material (K) present due to the production process is stored and / or deposited.

11. The method according to claim 9 or 10, characterized in that the catalytically active material (KU) of the substance (S) is the same as the catalytically active material (K), which in the manufacture of the catalyst module (3) on or was deposited.

12. The method according to any one of claims 9 to 11, so that the substance (S) is fed to the catalyst module (3) during catalyst operation. .

13. The method according to claim 12, so that the substance (S) is mixed with a substance (NO) which is fed to the catalyst module (3) to promote the conversion of the substance (NO).

14. The method according to claim 12 or 13, characterized in that the substance (S) is or is mixed with a fuel (B), in the combustion of which a substance (NO) is formed as exhaust gas, which the catalyst module (3) to promote the conversion of Substance (NO) is supplied.

15. The method according to any one of claims 1 to 14, characterized in that the catalytically active material (K, KU) contains atoms of one of the elements vanadium, titanium, tungsten, iron and / or molybdenum, and that the catalytically active material (K, KU ) is in particular an oxide of one of these metals.

16. Fuel (B) for combustion in a combustion process, which contains a substance (S) or which contains a substance (S) is added, which is catalytically active material (KU) or from which catalytically active material (KU) is formed during combustion, in particular for carrying out the method according to claim 5 or 14.

17. The fuel (B) according to claim 16, d a d u r c h g e k e n e z e i c h n e t that its substance content has a value between 10 mg / kg fuel and 200 mg / kg fuel.

18. The fuel (B) as claimed in claim 16 or 17, so that the substance (S) is present in dissolved or dispersed form or is added in soluble or dispersing form.

19. Fuel (B) according to one of claims 16 to 18, that the catalytic material (KU) has the property of promoting the conversion of a pollutant (NO) that is produced during combustion.

20. Fuel (B) according to one of claims 16 to 19, characterized in that the catalytically active material (KU) has the property of converting nitrogen oxide according to the principle of selective catalytic reduction to the exhaust gas formed during combustion is included.

21. Fuel (B) according to one of claims 16 to 20, d a d u r c h g e k e n n z e i c h n e t that - the catalytically active material (KU) contains at least one of the elements vanadium, titanium, tungsten, iron, molybdenum or mixtures thereof.

22. exhaust gas cleaning system (13), in particular for a combustion system of a power plant or for an internal combustion engine of a motor vehicle, in which a during combustion The resulting exhaust gas stream (A) is led to the conversion of a pollutant (NO) contained therein through a catalyst module (3), which is deposited on or in a catalytic conversion of the pollutant (NO) promoting catalytic material (K) Catalyst substrate (31) is produced, nitrogen oxide contained in the exhaust gas stream (A) being convertible in accordance with the principle of selective catalytic reduction, characterized by an injection device (8) with which a substance (S) can flow in the direction of flow (5). can be fed into the exhaust gas upstream of the catalyst module (3), the substance (S) being or containing catalytically active material (KU) or being able to be separated from the substance (S) catalytically active material (KU) (FIG. 1).

23. Exhaust gas purification system (13) according to claim 22, that the injection device (8) has a storage container (11) for receiving the substance (S).

24. Exhaust gas cleaning system (41), in particular for a combustion system of a power plant or an internal combustion engine of a motor vehicle, in which an exhaust gas stream (A) resulting from the combustion of a fuel (B) for converting a pollutant (NO) contained therein by a catalyst module (3) which is produced by depositing a catalytically active material (K) which promotes the catalytic conversion of the pollutant (NO) on or in a catalyst substrate (31), nitrogen oxide contained in the exhaust gas stream (A) in particular according to the principle of selective catalytic Reduction is convertible, characterized by a feed device (43) by means of which a substance (S) can be added to the fuel (B), the substance (S) being or containing catalytically active material (KU) or from the substance (S) being catalytically active Material (KU) can be deposited (Figure 6).

25. The exhaust gas purification system (41) according to claim 24, so that the feed device (28) has a storage container (45) for receiving the substance (S).