DE102022114422A1 - Fine dust reducing composition and method for reducing fine dust in a fireplace - Google Patents

Abstract

The invention relates to a composition for reducing the formation of fine dust during the combustion of solids, comprising at least a first component that reduces the formation of fine dust, which is selected from a group consisting of Al2O3, Al(OH)3, bauxite, talc, kaolin, kaolinite and kaolin-containing clays comprises, wherein the composition comprises a second particulate matter reducing component which is selected from a group comprising metakaolin, thermally activated trilayer silicates, fly ash and microsilica and/or combinations of these substances. The invention further relates to a method for burning a solid fuel in a fireplace with the addition of such a composition.

Description

The present invention relates to a method for reducing fine dust in a fireplace and/or boiler system as well as a fine dust-reducing composition and its use. The invention further relates to a method for producing such a composition.

It is known from the prior art that some Al-containing compounds such as Al ₂ O ₃ , Al(OH) ₃ , bauxite, talc and/or kaolin or kaolinite (but also kaolin-containing clays) act as additives in the combustion of solids can be added and reduce the formation of fine dust

For example, this is off DE 10 2020 128 231 A1 an incineration system is known, which includes a kaolinite storage and dosing device for releasing kaolinite into the combustion process.

Out of DE 10 2014 210 614 B4 Pellets made from a pressed biomass are known which contain an aluminum-containing inorganic compound, clay and/or a clay mineral as an ash and/or fine dust reducing additive. This additive is intended to make it possible to use raw materials alternative to firewood, such as chips from short rotation plantations (SRC), straw, grain and the like, for the production of pellets for heating purposes in small combustion systems.

Scientific studies on the influence of kaolinite on combustion and the resulting fine dust were also carried out. Particularly worth mentioning are studies carried out at the TU Hamburg (TUHH), especially at the Institute for Environmental Technology and Energy Economics. For example, in the article Huelsmann, T., Mack, R., Kaltschmitt, M. et al. Influence of kaolinite on the PM emissions from small-scale combustion. Biomass Conv. Bioref. 9, 55-70 (2019) https://doi.org/10.1007/s13399-018-0316-8 Studies on the influence of kaolinite on particulate matter emissions are described. These studies show that a higher proportion by weight of the addition of kaolinite does not necessarily lead to a reduction in particulate matter emissions. For example, at the test stand in Hamburg, with an addition of 1 percent by weight (wt.%) of kaolinite in pellets with an average of 94 mg/Nm ³ , almost the same level of fine dust emissions in the exhaust gas were detected as without the addition of kaolinite (average of 98 mg/Nm ³ ). In contrast, with the addition of only 0.5% by weight of kaolinite in pellets, an average significantly reduced fine dust load in the exhaust gas of only 53 mg/Nm ³ could be measured. An analog comparative measurement at the Technology and Support Center in the Competence Center for Renewable Raw Materials in Straubing led to different results, in which the fine dust emissions in the exhaust gas when 1% by weight of kaolinite was added to pellets compared to the fine dust emissions in the exhaust gas from burning pellets with a Addition of just 0.5% by weight of kaolinite could be reduced further.

As can be seen from the above-mentioned prior art, the selection of the additive is not the only decisive factor in reducing fine dust when burning solids. There seem to be other factors, particularly with additives containing kaolin or kaolinite, that significantly influence the degree of fine dust reduction.

There is therefore a need to provide a composition that is particularly effective. There is also a need to provide a method with which the formation of fine dust during the combustion of (particularly organic) solids can be reduced particularly efficiently.

This task can be solved by the subject matter of the independent patent claims. Preferred embodiments are described below as such and/or are the subject of the dependent claims.

The invention therefore relates to a composition for reducing the formation of fine dust during the combustion of solids, comprising at least one first component that reduces the formation of fine dust, which is selected from a group consisting of Al ₂ O ₃ , Al(OH) ₃ , bauxite, talc, kaolin, Includes kaolinite and clays containing kaolin. In addition, a composition according to the invention comprises a second component that reduces particulate matter formation, which is selected from a group that includes metakaolin, thermally activated three-layer silicates, fly ash and microsilica and / or combinations of these substances. It has been shown that the presence of the second component that reduces the formation of fine dust (hereinafter also referred to as the “second component”) reduces the formation of fine dust even at very low combustion temperatures, for example ≤ 650 ° C, ≤ 600 ° C, ≤ 550 °C or even ≤ 500°C and/or with incomplete combustion, for example due to low acidity material supply can be significantly reduced. Even at high combustion temperatures and sufficient oxygen supply, the composition according to the invention has proven to be advantageous because it improves ash formation and, by avoiding clumping or at least reducing the tendency of the ash to clump together, enables a good long-term supply of oxygen through the fuel and the combustion chamber.

For the reasons explained above, it is particularly preferred that the second component is suitable for binding fine dust-forming Na and/or K salts at combustion temperatures ≤ 650 ° C. This enables the entire composition to reduce the formation of fine dust even at such low combustion temperatures. How an addition of the second component can lead to an improvement in the reduction of fine dust formation, which essentially corresponds to the reduction of a similar proportion of the first component at high combustion temperatures, has not yet been clarified, but it is assumed that due to the presence of the second Component uses the binding of fine dust and the larger particles formed, if necessary in interaction with the first component, catalyzes the further binding and thus reduction of fine dust.

Preferably, the second component comprises one or more substances from a group comprising kaolin, halloysite, dickite and nacite, at least one of these substances being thermally activated. Thermal activation has proven to be advantageous for these substances, as this results in the conversion of kaolin to metakaolin, for example, which is particularly suitable for binding fine dust at low temperatures. It is assumed that at least partial thermal activation also takes place during the combustion process in the known compositions. However, this only occurs at comparatively high combustion temperatures, which are not reached in some areas of the combustion chamber and/or the flame or fire. In the case of compositions without a second component, the formation of fine dust cannot be reliably reduced depending on the flame temperature and the location of the feed in the combustion chamber

A composition in which the second component is present as a particulate solid has proven to be particularly suitable. This configuration allows a large surface-to-volume ratio to be achieved. It is believed that such a ratio is positive for achieving a temperature necessary to reduce particulate matter. In addition, the comparatively large surface area could promote the accumulation and thus binding of fine dust. However, the exact mode of action has not yet been fully analyzed.

Preferably the second component is thermally treated. It is preferably treated at a temperature in the range of approximately 600 - 900°C, preferably 650 - 800°C. At this temperature, for example, kaolin converts to metakaolin. During this thermal treatment, a reaction is preferably brought about in which previously bound crystal water is released. In addition to or as an alternative to the treatment at the above-mentioned temperature, the thermal treatment preferably takes place over a period of 1 - 90 minutes, preferably 5 - 75 minutes, particularly preferably 10 - 60 minutes. As can be seen from these values, it takes some time until there is sufficient or (almost) complete conversion to the reactive component, which can bind and/or reduce the fine dust produced during combustion particularly effectively.

It inevitably follows that without the addition of such a second component at certain times (for example at the beginning of a combustion process and immediately after adding the fine dust reducing component known from the prior art to an ongoing combustion) there is not enough of the reactive component to be present Effectively reduce the formation of fine dust.

Experience shows that uncontrolled combustion in a combustion chamber can result in temperatures in a very wide temperature range. This temperature range usually includes temperatures of around 100 - 1000°C. In this temperature range, the temperature for forming the reactive component (in particular metakaolin) which is particularly suitable for reducing fine dust may not be sufficient locally, or it may be locally too high and thus a further conversion to silicates with reduced reactivity takes place. The distribution of temperature in a combustion chamber can only be controlled to a limited extent, if at all, so that, for example, the formation of metakaolin during combustion cannot be controlled or controlled. Analogously, this often also applies to the residence time, which can last from a few seconds to several hours during a combustion. Wh If the residence time is too short, not enough of the reactive component can often be formed, while if the residence time is too long, the reactive component (for example the metakaolin) can be deactivated.

These disadvantages can be counteracted by the prior production of the second component and its use in a composition according to the invention.

An embodiment has proven to be particularly preferred in which the particles of the second component have a particle size (Sedigraph) d ₉₅ ≤ 100 µm, preferably ≤ 50 µm, more preferably ≤ 20 µm and particularly preferably ≤ 10 µm. Additionally or alternatively, particle sizes d ₉₅ ≥ 1 µm, preferably ≥ 2 µm, more preferably ≥ 3 µm and particularly preferably ≥ 5 µm are preferred. These minimum sizes can improve handling and, in particular, prevent these particles from entering the environment as fine dust even during handling.

The particle size is preferably adjusted by grinding and, if necessary, subsequent sieving and/or sifting.

The ratio of the first component to the second component can be varied within a comparatively wide range and thus adapted to the conditions occurring during combustion. For example, in a preferred composition there may be a ratio of the first component that reduces fine dust formation to the second component that reduces fine dust formation in the range of 1:99 - 99:1.

However, a ratio of the first component to the second component in the range of 50:50 - 98:2, more preferably 60:40 - 95:5 and particularly preferably 75:25 - 90:10 has proven to be preferred. In this ratio, the reduction of the fine dust produced during combustion can be effective even at comparatively low temperatures, without disproportionately increasing the cost of the composition due to the second component - which is often more expensive due to activation.

In order to keep the costs for the second component low, the use of residues from other processes has proven to be particularly advantageous. When using fly ash, it is preferred that it comes from large-scale industrial processes such as electricity generation in coal-fired power plants. If, on the other hand, microsilica is used as a component or basis of the second component, it preferably comes from the fine dust produced during the production of Si metal.

In a preferred embodiment, the composition comprises a combustible substance. This is preferably selected from a group that includes wood, straw, husks, grass, bran, yeast cells, grain, hemp, fruit and/or vegetable seeds or peels, lignite, lignite coke, lignite powder, dry stillage (DDGS), hard coal, hard coal coke , hard coal powder, charcoal, charcoal powder and petroleum coke. This combustible substance can be added to the composition in a combustion chamber or mixed with the other components of the composition outside of a combustion chamber. It is conceivable, for example, to press a fuel with other components of the composition, for example into logs, briquettes, pellets or similar forms that are easy to handle (and preferably without excessive dust formation).

Pure dosage variants as well as dosage variants in conjunction with other substances such as carrier materials have proven to be advantageous as the preferred dosage form of the composition. For pure dosage variants, the powder or granulate form has proven to be particularly suitable. A particularly suitable variant of administration in conjunction with other substances is the use of a suspension.

In addition, a dosage form in the form of compacted tablets has proven to be particularly suitable. Such a compacted compact can be in the form of a pellet, briquette and/or pressed log, for example. The first and second components of the composition can be pressed together or other substances such as auxiliary substances can be added. Both organic and inorganic auxiliary materials are conceivable as auxiliary materials. These can, for example, ensure that at elevated temperatures such as those in a combustion chamber, a compact disintegrates or is blown apart and thus a particularly large reactive surface is available for binding fine dust-promoting substances to the surface of the particles of the first and second components.

Depending on the application, the (weight) proportion of the auxiliary substances in the composition can be selected in a very large range of 99.9 - 0.1, preferably 99-1, more preferably 75 - 25. In particular, if an auxiliary substance is a fuel, it can be well over 75%, for example over 90%, ≥ 95% or even ≥ 98% and in particular be present in a very large excess compared to the first and / or second component.

Preferably the composition comprises a binder. Such a binder can be an auxiliary substance as mentioned above. It is particularly preferred that the composition has a binder if the composition is in the form of a pellet, briquette, granulate and/or pressed log. The binder is preferably selected from a group including hydrocarbon-based materials, oil, wax, paste and flour. These have proven to be particularly suitable for releasing the first and second components of the composition during combustion and for releasing no or only extremely small amounts of harmful substances during combustion, for example in the exhaust gas or the ash.

The composition preferably comprises a fuel. In particular, it is preferred that the composition comprises several different fuels. Preferably, a fuel of the composition can be burned with little or no fine dust formation. In addition or as an alternative to this, a fuel can preferably be burned with the formation of fine dust. This fuel, which can be burned with the formation of fine dust, is preferably the fuel whose formation of fine dust is to be reduced. As explained above, this (fine dust-forming fuel) is preferably selected from a group that includes wood (for example as pellets, logs, wood chips, shavings, pressed wood), straw, husks, grass, mulch, bran, yeast cells, grain, hemp, fruit - and/or vegetable kernels or peels, lignite, lignite coke, lignite powder, dry stillage (DDGS), hard coal, hard coal coke, hard coal powder, charcoal, charcoal powder and petroleum coke. However, the fuel is not limited to the substances mentioned.

Regardless of the choice of fuel, it is preferred that the proportion of the second component, based on the fuel, be in the range of 0.05 - 5% by weight. It has been shown that with this proportion the amount of fine dust that would normally be produced when the fuel is burned can be reduced particularly efficiently. A proportion of 0.1 - 4% by weight, more preferably 0.15 - 3% by weight and particularly preferably 0.2 - 2.5% by weight has proven to be particularly efficient and therefore preferred.

Mixing ratios of the first to the second component of the composition in the range of 10:1 - 3:10, preferably 9:1 - 4:10, particularly preferably 8:1 - 5:10 have proven to be particularly preferred. Larger mixing ratios can be more cost-effective, whereas smaller mixing ratios already contain a larger proportion of the second component and can therefore already be active independently of any chemical conversion caused by the combustion itself.

A mixture as described above is preferably prepared together with at least one auxiliary substance, for example with a binder and a combustible substance, as a compact (for example as a briquette or pellet). A composition in the form of such a compact preferably has the first and second components in a total amount of 30 - 95%, preferably 40 - 90%, particularly preferably 50 - 80%.

If such a pellet (for example pellet or briquette) is burned in a furnace together with an additional (for example as described above) fuel, the pellet is preferably added in an amount such that the sum of the (weight) proportions of the first and second components based on the total mass used for combustion (i.e. including the fuel) is preferably in the range of 0.05 - 5% by weight, since with this proportion the amount of fine dust that would otherwise normally be produced when the fuel is burned can be reduced particularly efficiently . In particular, a proportion of 0.1 - 4% by weight, more preferably 0.15 - 3% by weight and particularly preferably 0.2 - 2.5% by weight has proven to be particularly efficient. Using the example of a pellet as described above with, for example, 60% by weight of the first and second components, this means that approximately 1 g per 20 kg of fuel should be used in order to obtain a sum of the (weight) proportions of the first and second components to reach the total mass used for firing of 2.9% by weight.

The aforementioned preferred sum of the (weight) proportions of the first and second components based on the total mass used for firing are independent of the packaging the composition has proven to be advantageous. For example, when using the composition as a powder or granulate, proportions in the above-mentioned range are advantageous.

Preferably, through the choice of the recipe (in particular the selection of the first and/or second component as well as the use of optional auxiliary materials) and/or the packaging (form of addition) and/or frequency, their addition to the combustion chamber of the oven/heating point and the respectively recommended The amount of fuel to be added, the proportion of the sum of the (weight) proportions of the first and second components, is kept within the above-mentioned framework throughout the entire combustion process.

• - mindestens eine erste die Feinstaubbildung reduzierende Komponente, welche ausgewählt ist aus einer Gruppe, die Al₂O₃, Al(OH)₃, Bauxit, Talkum, Kaolin, Kaolinit und kaolinhaltige Tone umfasst, und
• - eine zweite, die Feinstaubbildung reduzierende Komponente, welche ausgewählt ist aus einer Gruppe, die Metakaolin, thermisch aktivierte Dreischichtsilikate, Flugasche und Mikrosilica und/oder Kombinationen dieser Substanzen umfasst.

Another essential aspect of the present invention is a method for burning a solid fuel in a fireplace. In this case, a composition is added to the fuel to reduce the formation of fine dust. This composition includes

• - at least one first component that reduces fine dust formation, which is selected from a group that includes Al ₂ O ₃ , Al (OH) ₃ , bauxite, talc, kaolin, kaolinite and kaolin-containing clays, and
• - a second component that reduces fine dust formation, which is selected from a group that includes metakaolin, thermally activated three-layer silicates, fly ash and microsilica and / or combinations of these substances.

This process can effectively reduce the formation of fine dust when burning (solid) fuels.

Adding the particulate matter reduction composition to the fuel may occur before or during combustion of the fuel and may occur separately from the fuel or together with fuel. For example, the addition can take place when lighting and/or adding fuel. In addition or alternatively, the addition can take place outside or in the combustion chamber or combustion zone.

In a preferred variant of the process, a composition is used as described above on the product side.

In a preferred process variant, the composition is added to the fuel in an amount in which the proportion of the second component that reduces fine dust formation, based on the fuel, is in the range of 0.05 - 5% by weight, preferably 0.1 - 4% by weight. -%, more preferably 0.15 - 3% by weight and particularly preferably 0.2 - 2.5% by weight. It has been shown that a particularly efficient reduction in fine dust is possible with a proportion from this range. At the same time, the costs of the composition can be kept low.

With regard to the fireplace, there are no restrictions on using a composition as described above and/or carrying out the method described above. The composition can be used extremely flexibly. It can be used, for example, in individual fireplaces and in boiler systems of any size. There is also great flexibility in the manner, timing and location of adding the composition to the fuel.

By means of a method as described above and/or a composition as described above, it is possible to reduce the amount of fine dust when a solid is burned by at least 10%, preferably at least 25%, more preferably at least 50% and in many cases are particularly preferred, even reduced by 75% or more. The percentages mentioned in this regard (like all other percentages mentioned in the context of this disclosure, unless otherwise defined) refer to percent by weight. In this case, the basic size is the amount of fine dust formed without the addition of the composition according to the invention.

Preferably, the amount of total dust produced during combustion can also be reduced. Preferably, a reduction of at least 10%, preferably at least 25%, more preferably at least 50% and particularly preferably at least 75% is possible.

In addition to reducing the fine dust produced during combustion, a composition according to the invention can in many cases also improve the ash sintering behavior, in particular avoiding or at least reducing the sintering of the ash.

In many cases, the addition of a composition as described above also leads to a reduction in the CO content in the exhaust air. This can be attributed, among other things, to the improved ash sintering behavior and the associated better supply of fresh air and/or oxygen and the associated more complete combustion.

Preferably, a cost saving can be achieved by a composition as described above and/or the method described above, since exhaust gas aftertreatment or exhaust gas purification can be dispensed with or the systems and equipment necessary for this must be designed to be smaller or less complex.

Preferably, the composition is designed, suitable and/or intended to carry out a method as described above as well as all method steps described in connection with the method individually or in combination with one another or individual method steps using the composition described above. Conversely, the method can be carried out individually or in combination with all the features described in the context of the composition.

The present invention is further directed to a fireplace in which at least some and preferably all of the method steps of the method according to the invention and preferably one of the preferred embodiments described can be carried out. Such a fireplace preferably has a device for supplying a composition as described above to a combustion chamber or a mixing chamber.

The present invention is further directed to a control device which is designed to control a system (for example a fireplace) so that it carries out the method or parts thereof as described above.

Results of comparative studies are presented in the following tables.

Table 1 shows the results of fine dust measurements on a single pellet stove, manufacturer ANSELMO COLA, type URBAN, NWL 1.99-7.1 0kw. If a composition according to the invention (referred to as “additive” in the table) was added to the fuel, it was used in a mixing ratio of pellet (fuel) to composition of 4kg to 20g. Table 1 Measurement time fuel Description Fine dust [mg/m ³ ] 1 9:15-9:30 pellet Measurement at full load without additive 13.7 2 9:45-10:00 pellet Measurement at full load without additive 14.8 3 10:15-10:30 pellet Measurement at full load without additive 15.2 9 12:20-12:35 pellet Measurement at full load with additive 0.5% 6.4 10 12:40-12:55 pellet Measurement at full load with additive 0.5% 5.6

These results clearly show that even with the addition of 0.5% by weight of the additive (a powdered variant of the composition according to the invention), a significant reduction in the fine dust produced could be measured. The amount of fine dust could be reduced to less than 50% based on the mean value of comparative measurements 1 - 3.

Table 2 shows the results of fine dust measurements on a single fireplace for logs, manufacturer Austroflamm, type CLOU Xtra, NWL 8kw. If a composition according to the invention (referred to as “additive” in the table) was added to the firewood, it was added in a mixing ratio of approximately 1.2 - 1.4 kg of firewood to 10 g of additive. Table 2 Measurement time fuel Description Fine dust [mg/m ³ ] 4 10:40-10:55 logs 1.3 kg without additive 38.2 5 11:00-11:15 logs 1.4 kg without additive 34.2 6 11:20-11:35 logs 1.4 kg without additive 36.8 7 11:40-11:55 logs 1.3 kg with 10 g additive (pellet) 20.5 8th 12:00-12:15 1.4 kg with 10 g additive (pellet) 22.3

Unlike the measurements shown in Table 1, in the measurements shown in Table 2 the additive was used in a form pressed into a pellet. The results of these measurements also clearly show that a significant reduction in the fine dust produced could be measured with the addition of approximately 0.7 - 0.8% by weight of the additive (a variant of the composition according to the invention pressed into pellets). Although the amount of fine dust - unlike the measurements according to Table 1 - could not be reduced to less than 50% based on the mean value of comparative measurements 4 - 6, here too a reduction to well under 60% was achieved. The lower effectiveness of the additive in the tests according to Table 3 can be explained by the reduced surface area of the additive pressed into pellets.

The applicant reserves the right to claim all features disclosed in the application documents as essential to the invention, provided that they, individually or in combination, are new compared to the prior art.

QUOTES INCLUDED IN THE DESCRIPTION

This list of documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102020128231 A1 [0003]
• DE 102014210614 B4 [0004]

Non-patent literature cited

• Huelsmann, T., Mack, R., Kaltschmitt, M. et al. Influence of kaolinite on the PM emissions from small-scale combustion. Biomass Conv. Bioref. 9, 55-70 [0005]

Claims (10)

Composition for reducing the formation of particulate matter during the combustion of solid matter, comprising at least a first component that reduces the formation of particulate matter, which is selected from a group that includes Al ₂ O ₃ , Al(OH) ₃ , bauxite, talc, kaolin, kaolinite and kaolin-containing clays , characterized in that the composition comprises a second particulate matter reducing component selected from a group comprising metakaolin, thermally activated trilayer silicates, fly ash and microsilica and/or combinations of these substances. Composition according to Claim 1 , characterized in that the second component that reduces fine dust formation is suitable for binding fine dust-forming Na and/or K salts at combustion temperatures ≤ 650 ° C and preferably comprises one or more substances from a group that includes kaolin, halloysite, dickite and Nakit includes, at least one of these substances being thermally activated. Composition according to one of the preceding claims, characterized in that the second component which reduces the formation of fine dust is present as a particulate solid, which preferably has a particle size (Sedigraph) d ₉₅ ≤ 100 µm, preferably ≤ 50 µm, more preferably ≤ 20 µm, particularly preferably ≤ 10 µm. Composition according to one of the preceding claims, characterized in that a ratio of the first component reducing the formation of fine dust to the second component reducing the formation of fine dust is in the range of 1:99 - 99:1, preferably 50:50 - 98:2, more preferably 60: 40 - 95:5 and particularly preferably 75:25 - 90:10. Composition according to one of the preceding claims, characterized in that it comprises a combustible substance, which is preferably selected from a group consisting of wood, straw, husks, grass, bran, yeast cells, grain, hemp, fruit and/or vegetable kernels, brown coal , lignite coke, lignite powder, dry stillage (DDGS), hard coal, hard coal coke, hard coal powder, charcoal, charcoal powder and petroleum coke. Composition according to one of the preceding claims, characterized in that the composition comprises a binder and is preferably present as a pellet, briquette, granulate and/or pressed log, the binder being preferably selected from a group consisting of hydrocarbon-based materials, oil, wax, Includes paste and flour. Composition according to one of the preceding claims, characterized in that it comprises a fuel which can be burned with the formation of fine dust, the proportion of the second component which reduces the formation of fine dust, based on the fuel, preferably being in the range of 0.05 - 5% by weight, preferably 0.1 - 4% by weight, more preferably 0.15 - 3% by weight and particularly preferably 0.2 - 2.5% by weight. Method for burning a solid fuel in a fireplace, characterized in that a composition for reducing the formation of fine dust is added to the fuel, this composition - at least one first component reducing the formation of fine dust, which is selected from a group consisting of Al ₂ O ₃ , Al(OH) ₃ , bauxite, talc, kaolin, kaolinite and kaolin-containing clays, and - a second component which reduces particulate matter formation and which is selected from a group consisting of metakaolin, thermally activated three-layer silicates, fly ash and microsilica and/or combinations of these Substances included. Method for burning a solid fuel in a fireplace Claim 8 , characterized in that the composition is a composition according to one of the Claims 1 - 6 is or includes such a composition. Method for burning a solid fuel in a fireplace according to one of Claims 8 - 9 ,: characterized in that the composition is added to the fuel in an amount so that the proportion of the second component that reduces fine dust formation is based on the Fuel in the range of 0.05 - 5% by weight, preferably 0.1 - 4% by weight, more preferably 0.15 - 3% by weight and particularly preferably 0.2 - 2.5% by weight lies.