EP1354022A2

EP1354022A2 - Transforming animal meal into fuels

Info

Publication number: EP1354022A2
Application number: EP01989423A
Authority: EP
Inventors: Klaus-Rainer Töllner; Manfred Hessel; Ursula Perplies; Robert Leweke; Bernhard Josef Budde
Original assignee: Individual
Current assignee: Individual
Priority date: 2001-01-02
Filing date: 2001-12-21
Publication date: 2003-10-22
Also published as: AU2002227877A1; WO2002053686A3; WO2002053686A2

Abstract

The invention relates to a method for transforming animal meal into fuels, particularly for industrial combustion plants, such as power stations, furnaces or combustion ovens. The animal meal is mixed with at least one additive, which can be a substance containing carbon and/or minerals and/or metal to form a mixture and is rolled under pressure into pellets or briquettes. The invention also relates to a solid fuel based on organic material, consisting essentially of animal flour and at least one additive and is embodied as a pressed item in the form of a pellet or briquette. The invention also relates to a method for disposing animal residues, particularly animal meal with the aid of the above-mentioned method.

Description

Processing animal meal into fuels

The invention relates to a method for processing animal meal into fuel and to a solid fuel essentially produced from animal meal according to the preamble of patent claim 1 and of patent claim 8.

Animal meal represents an end product in the disposal of animal carcasses that has previously been used as animal feed. However, animal meal feed has recently proven to be critical, particularly in the context of the BSE problem, so that, in the current legal situation, animal meal may no longer be used as animal feed for reasons of epidemic hygiene. However, the burning of animal meal is problematic in many ways when using normal, untreated animal meal and poses technical as well as health and labor protection problems.

For example, animal meal is high-energy in terms of its energy content and there is a risk of dust explosions during processing. This is especially true when the animal meal is in an essentially dry state and in a fine distribution. In addition, animal meal is suitable for triggering allergies due to its high protein content There is a risk of the possible transmission and generation of infections, so that the processing generally makes protective work ^clothing necessary.

Furthermore, for reasons of epidemic hygiene, it must be ensured that the material is no longer consumed by animals, so that unauthorized use of the animal meal for feeding purposes is prevented per se.

In addition to the problems already mentioned, however, the combustion of animal meal is also not easily possible and involves numerous problems, which are essentially technically justified. For example, feeding the animal meal to a reduction device is problematic, since pure animal meal tends to produce blockages in the supply lines. Furthermore, bridging and other technical problems in the combustion process are to be feared and must be given special attention when feeding to the furnace. At this point, therefore, a fuel is required that is both blowable, free-flowing and largely abrasion-resistant. The abrasion resistance is also desirable in order to avoid dust formation during transport, storage and introduction into the oven.

From what has been said and from the fact that, especially in the field of animal husbandry, large quantities of animal meal will continue to be produced in the future, it emerges that there is an urgent need for a disposal facility for There is animal meal, and from an economic point of view, optimal use of resources should also be a priority, particularly with regard to the high energy content of animal meal, which roughly corresponds to that of wood or lignite. Another important point is that thermal treatment of animal meal has to be carried out in such a way that the organic substances contained in the animal meal are completely destroyed. Such temperatures are theoretically given in coal-fired power plants or in kilns of cement factories. However, it has been shown that in practice the addition of animal meal to large combustion plants does not lead to sufficient destruction of the protein substances and therefore protein residues are found in the ashes and in the flue gases.

Since animal meal is still a quasi-renewable fuel raw material, it is also desirable from an energy-economic point of view that this resource can be used safely and functionally optimized for energy generation, both technologically and physiologically , There is a corresponding demand both from the electricity industry and from the cement industry.

It is therefore the object of the present invention to show a method for processing animal meal into fuel and a fuel produced therefrom, the above-mentioned disadvantages being avoided and the parameters with regard to the processability shown physiological harmlessness and optimal use of resources are complied with and, in addition, recycling or disposal of animal meal is possible using the method.

This object is achieved by a method according to claim 1 and by a solid fuel according to claim 8.

An essential idea of the invention is to condition animal meal using additives with regard to the form of further use in such a way that it does not pose any technical, general epidemic and other health risks for the employees concerned, but also for the environment, in the Usually used furnaces for heat generation and for the production of process energy, in particular in the course of commercial activities, can preferably be used in cement and power plants.

The product as a result of the process described below is an energy-rich fuel in a preferably solid, possibly also dusty or floury form, which fulfills the aforementioned requirements. This product can be obtained by rolling the animal meal mixed with the additive (s) or by preferably compressing the fuel material. The risk of dust explosions or other contamination with dust in the wide _¬ ren use is avoided by the processing of the fuel to a pressure. The product represents a versatile fuel to ^¬ which by a suitable choice of the additives, the Mischungsver ^¬ holds isses and dimensions of the compacts or the granularity of the unpressed final material exactly to the respective specific needs of the respective combustion furnace in terms of heat value Introduction to the combustion chamber, adaptation to the grid and the dimensioning of the grate can be adjusted.

In particular, the object is achieved by a method for processing animal meal into fuel, in particular for industrial firing systems, in which the animal meal is mixed with at least one additive, as the starting materials for producing the fuel according to the invention, to form a mixture to be pressed and one is then subjected to pressure treatment. The pressure treatment preferably comprises rollers or a shaping pressure treatment, in which pellets or bricks are preferably produced.

Crumbling of the pellets is also avoided according to the invention in that at least one additive is added to the animal meal and this is intimately mixed with the animal meal. By adding the additive, the adhesiveness of the animal meal or the mixture is improved, so that the mixture can be shaped into dimensionally stable and essentially abrasion-resistant pellets or bricks. Crumbling even with little force is generally not to be feared. By pressing in the course of the production of the fuel, the animal meal is also chemically and physically bound to the aggregate in such a way that uniform and homogeneous combustion is ensured, with the result that temperatures and oxidation processes are achieved in the overall area of the combustion of the fuel ensure that proteins, especially the prions responsible for the spread of BSE, do not remain in the ash or in the exhaust air flow from the combustion. The animal meal conditioned with the process described below and the problematic or dangerous organic compounds contained therein disintegrate safely and completely in the combustion process and are no longer detectable in the ashes as well as in the flue gases.

In addition, the compacts produced are so resistant to abrasion under conventional conditions of use that secondary dust is avoided during product handling during transport, intake and supply for combustion, but at least to a negligible, but in any case harmless, degree is reduced. This concerns both technical dangers, in particular that of a dust explosion, but also reduced pollution of machines and equipment, as well as general epidemic hygiene dangers due to the unintentional spread of animal meal in the area, and special health hazards for the employees entrusted with handling the fuel. In particular, the dangers of inhaling dust and the ingestion of disease germs from the animal meal, which occurs via the respiratory tract and lungs, should be mentioned here.

At this point it should be mentioned that in the context of this invention the terms animal meal, additives), compact (s) and pressing are to be understood according to the following definitions:

MBM:

Residue produced by processing animal carcasses according to known methods, consisting of proteins, fats, carbohydrates, minerals, including bone meal, and other organic constituents originally contained in carcasses, in a floury, dusty or pulpy consistency. Animal meal in this sense is also:

so-called milk replacer. This includes milk powder, in which the natural fat of the milk has been removed and replaced by animal carcass fat, which is produced in the production of usual animal meal, and

Slate, how this arises in the production process of animal meal production as an intermediate product before cooling and grinding the end product "animal meal". Aggregate (s):

Mixtures in a floury, dusty or pulpy consistency, consisting of brown coal, hard coal, cellulose, wood, gypsum, sewage sludge, rejects, deinking sludge, plastic, denaturing agents or other carbonaceous, especially combustible, materials and metal dusts.

Pellet (e):

End product (= fuel) brought in the form of pellets, briquettes or other pressed forms.

pressing:

Mixing and subsequent pressing or rolling to reduce the volume and to achieve an intimate connection and conveyance of chemical compounds of the animal meal and the additives in the course of the production of the fuel.

Combustion:

Either direct combustion or gasification and subsequent combustion at temperatures of preferably above 800 ° C. According to one embodiment of the invention, the mixing of the animal meal with at least one additive is carried out in a mixer using negative pressure or a pressure reduced compared to atmospheric pressure. Accordingly, the animal meal is fed in a closed feed system - likewise under negative pressure - to the measuring device, preferably a roller, pelletizer or bricket operator. In this way, an unintentional, in particular dusty, discharge of the mixture from the mixer is avoided. Furthermore, the mixer is closed in a dust-tight manner during the collapse and mixing process, in particular encapsulated, in order also to prevent unintentional loss of substance or dust discharge.

Further safeguards which, according to a development of the invention, are carried out before the starting substances are mixed and the mixture is subjected to pressure treatment are that the starting material animal meal is delivered and stored in closed containers. Any grinding process of the starting materials that may still be required in order to bring them into a powdery, flour-like or pulpy consistency is also encapsulated, like the actual production process.

According to one embodiment, the entire system is constantly kept under a slight negative pressure (= approx. 0.8 to 0.9 atm.), The air drawn off by a suitable pump advantageously using of a cyclone of portions of the starting materials contained therein, in particular animal meal, is cleaned.

According to a further embodiment of the invention, a carbon-containing and / or mineral and / or metal-containing substance is used as the additive. In particular, coal dust and / or sawdust and / or gypsum and / or cellulose and / or rejects and / or deinking sludge and / or sewage sludge and / or plastic and / or metal dust and / or denaturing agents and / or denaturants are particularly suitable.

The additive preferably contains non-oxidized carbon and groups which are capable of hydrogen bonding, a dipole-dipole or a van der Waais interaction with the constituents of the animal meal at free valences, the additive also preferably in a fissured form is present, which makes it possible to bring the aggregate and the animal meal in close, preferably in-tuned, connection, in which the animal meal penetrates into the fractured structure of the additive. This process is supported by the action of the fluid contained in the animal meal or the additives or, as explained below, additionally added fluid, in particular water. In particular, a high porosity of an additive is well suited for the process according to the invention due to the large surface area thus available. Suitable additives can essentially be differentiated according to their adhesion-promoting and / or combustion-promoting properties or denaturing properties.

The first two include aggregates that have disordered spatial structures, such as folds, cavities and the like depressions, as well as graphitic components, polar binding centers or dipole structures or unsaturated valences. Lignite dust, hard coal dust, sawdust, gypsum, deinking sludge and residues from the recycling process of paper such as cellulose and rejects, but also sewage sludge, have proven to be suitable here.

The denaturing agents which primarily serve to make the animal meal no longer accessible to feeding and which are intended to reliably prevent misuse are essentially commercially available denaturing agents, such as those for denaturing ethyl alcohol which is not intended for drinking purposes be used. Examples include 2-butanone or pyridine bases, but also other suitable denaturing agents such as chloroform or toluene.

Additives to be used are preferably added as dust or flour or as a chunky ingredient. This enables a sufficient and intimate mixing of the admixtures with the animal meal, the animal meal and the dust wetting or encasing each other and the animal meal, in particular in fissile components can penetrate so that a good mutual bond, in particular after pressing, is made possible and there is no risk that pellets or bricks break apart due to an inhomogeneous structure as a result of inhomogeneous mixing and a resulting poor adhesion of the components.

According to an advantageous development of the invention, the substances that are considered as additives are themselves combustible or combustion-promoting or suitable for influencing the calorific value of the pellets or bricks produced, it being emphasized that the above list is not to be understood as conclusive. For example, oxygen-releasing substances, such as highly oxidized salts, are also suitable as additives.

According to a development of the method, the additives are used in a quantity range from 0.5 vol.% To 20 vol.%, Preferably in a quantity range from 1.5 vol.% To 18 vol.% And particularly preferably in a quantity range from 3% by volume to 15% by volume are added to the mixture, the stated quantity ranges based on the total proportion of additives.

Furthermore, it is possible to add a fluid, preferably water, to the mixture in order to suppress potential dust formation during the processing operation on the one hand and on the other hand to initiate a certain stickiness or additional adhesiveness of the substances in the mixture and also to promote migration of additives and animal meal to and into one another.

At this point it is also possible to add an organic solvent, a wetting agent or another surface-active substance, in particular a fluid that reduces the surface tension, to the mixture. A fluid is advantageously used here which has a low enthalpy of vaporization or can itself serve as fuel. Another, preferably fire-accelerating, preferably carbon-containing fluid can also be added in addition or exclusively.

However, it should be emphasized that the addition of a fluid can also be dispensed with entirely, provided that the animal meal and / or the additives have sufficient adhesiveness for pellet formation as well as a suitable surface quality and / or moisture.

The fluid can either be added to the mixture during mixing, or it can be added immediately prior to pelleting, the latter being preferred.

Another additive to be added is metal dust from a vividly oxidizing metal or an alloy or solution of different metals. The oxidation of the metal dust promotes the combustion process of the mass and causes a reduction of organic compounds around the oxygen contained therein.

The raw materials are mixed to form a homogeneous, slightly pasty mass, depending on the moisture content, and this is then pressed or rolled. As a result, chemical or physical bonds, preferably through hydrogen bonds, dipole-dipole or van-der-Waals interactions, are achieved on the one hand through close spatial attachment, preferably incausticization of the starting materials to one another. The pressing can also give shape to presses of different dimensions. The dimensional stability of these compacts is achieved by a suitable choice of the dimensioning in the shaping and by a suitable choice of the pressing pressure and, in the case of pellets, also the thickness of the die plate or the die ring. With a suitable carbon fan part of the aggregate and a suitable pressure of the pressing process, dimensionally stable and largely abrasion-resistant pellets or briquettes are produced, provided that the shaping pressure of the pressing process according to a development of the invention is in the range from 15 bar to 250 bar, preferably in the range of 25 bar to 200 bar and particularly preferably in the range from 30 bar to 180 bar and in particular exceeds 120 kg / cm ² . It applies that sufficiently stable and abrasion-resistant compacts can be produced if the pressure is correspondingly low during the production of compacts with larger dimensions. near increases. The pellet shape should not be significantly less than 15 mm thick.

The pellets are preferably produced by means of a pelletizer in a size in the range from 5 mm to 30 mm and preferably in the range from 10 mm to 25 mm, larger pellets or bricks with a size in the range of 50 mm depending on the composition of the mixture up to 500 mm, preferably in the range from 100 mm to 300 mm and particularly preferably in the range from 150 mm to 250 mm. The decisive point here is that the adhesive's adaptability is adapted to the size of the pellets or bricks to be produced in such a way that the pellets or bricks are sufficiently strong after the mixture has been pressed.

At this point it should be mentioned that, of course, sticky additives for the production of very large bricks are also part of the invention.

The conditioning of the animal meal with one or more additives is achieved in that these, in particular lignite or hard coal in powdery, floury or pulpy form, have extremely disordered structures in the form of folds and / or cavities in graphite parts thereof, into which by the pressing process Animal meal is backfilled. The cavity dimension of the additive added to the animal meal is reduced by the fact that between the polar binding centers, such as the proteins or protein fragments of the animal meal and unsaturated valences of the carbon, and any humic acid present (for example in the case of lignite dust, meal, pulp as an additive) new major and minor valences arise. Among other things, hydrogen bonding occurs at the unsaturated valences of the carbon, which reduces the cavity dimensions and the folding structures of the admixtures. At the same time, a volume concentration is achieved in connection with the pressing.

In addition, according to the aforementioned, non-polar regions of the constituents of the mixture also accumulate. Here too, for example, van der Waals bonds are formed, which in turn also contribute to a volume contraction.

In particular, adhesive forces act between small carbon granules of the starting material, which are generated in that the carbon granules are brought sufficiently close together by the pressing process. The same also applies to graphite crystals that are present in the starting material. The adhesion effect is enhanced by the proteins of animal meal, which with their predominantly polar structures generate particularly strong intermolecular bonds and hydrogen bonds of the type already mentioned. The aforementioned process makes it possible to produce solid and largely abrasion-resistant pellets of various sizes, which can be adapted exactly to the needs of the furnace. The end product is a homogeneous, non-hazardous fuel that can be produced technically in large quantities and in a reproducible manner at any time. The calorific value of the fuel can be individually adjusted by changing the mixing ratio of the components.

Likewise, the material can be mixed with almost any other fuel that is used in the stoves in question. A mixture with rejects, with different plastics or plastic fractions and last but not least a mixture with paper, but also above-mentioned combustible and / or aggregate materials is particularly advantageous. At this point it should be mentioned that the animal meal-based pellets or bricks can also be coated with substances that promote combustion or ensure slow combustion, if this is desired.

Depending on the size, the material is blowable and / or free-flowing and can be fed to a combustion furnace with the usual feed devices. Blockages in the feed lines due to the animal meal components are not to be feared with a fuel according to the invention. The treatment of the end product, preferably after molding, is carried out conventionally; Because of the dimensional stability, abrasion resistance and freedom from dust that are achieved, dangers with regard to general epidemic hygiene and with regard to the health of the employees are reduced to such an extent that a simple dust filter as mouth and nose protection is sufficient to protect the employees directly involved in handling the product. Both the nature of the finished pulp material and the production process of the material itself make it possible to avoid direct skin contact in all stages of production, processing and use.

Furthermore, the object is achieved by a solid fuel based on organic material, in particular for industrial combustion plants, such as power plants, kilns or incinerators, the solid fuel consisting essentially of animal meal and at least one additive.

The solid fuel is preferably in the form of pressings, in particular in the form of pellets or bricks with the above-mentioned dimensions or in a rolled form.

According to the invention, the solid fuel has, as an additive, carbon-containing and / or mineral and / or metal-containing substances, in particular coal dust such as lignite dust and

Hard coal dust, sawdust, gypsum, cellulose, rejects, Deinking sludge, sewage sludge, plastics), metal dust, denaturing and denaturing agents. The aggregates are available individually or in combination and ensure the mechanical stability, abrasion resistance and good oxidizability of the solid fuel.

The total concentration of the additives present in the solid fuel is in the range from 0.5% by volume to 20% by volume, preferably in the range from 1.5% by volume to 18% by volume and particularly preferably in the range from 3% by volume % to 15% by volume, the additives preferably being intimately mixed with the animal meal and being homogeneously distributed in the solid fuel. However, it should be emphasized that it is also possible to build up the pellets or bricks in layers, in particular if they are spherical or oval in shape, the layers having different reaction enthalpies with regard to their oxidizability or flammability.

Furthermore, if necessary, the solid fuel can have one or more fluids as coagulation or adhesion aids and / or as regulating agents with regard to flammability and / or as denaturants. Essentially water is considered here, but organic fluids are also possible, in particular with regard to denaturation. At this point it should be mentioned that the solid fuel, for example in combination with easily flammable organic Any kind of igniter can also be used in fluids, although this plays a subordinate role here.

Otherwise, the present object is achieved by using the method shown above, which is suitable for disposing of animal residues, in particular animal meal.

The above method for producing a fuel from animal meal is excellently suitable for this, since an essentially complete and residue-free disposal of animal residues is possible with the use of optimal energy resources. Using the solid fuel generated by the process, it is possible to do without fossil, non-renewable, fuels at least partially in the application areas mentioned. In addition, health concerns arising from animal residues, in particular from animal meal, have largely been eliminated after the solid fuel according to the invention has been produced in accordance with the process outlined.

Further embodiments of the invention result from the subclaims.

The invention is described in more detail below using an exemplary embodiment.

80% animal meal, 4% lignite dust, 4% hard coal dust, 1% sawdust, 3% metal dust, 1% gypsum, 1, 5% cellulose and 5% clarifying Sludge and 0.5% denaturant are ground in a mill to a homogeneous material, then mixed and then preferably pressed into pellets or bricks. The pressure is 180 kg / cm ² . When producing pellets, the hole diameter of the die is 9 mm and its thickness is 45 mm. The resulting solid fuel is free-flowing and blowable, does not show any abrasion and is dimensionally stable even under the loads and pressures on the compacts that are normal.

This process therefore relates to a safe and safe form of disposal of animal meal and an excellent fuel for industrial ovens for generating heat and process energy in both dusty, floury, pulpy and preferably compressed consistency.

It can be seen from the above that the present invention relates not only to a method for processing animal meal into fuel, but also to a solid fuel and a method for the disposal of animal residues.

At this point it should be pointed out that all the parts described above are viewed on their own and any combination is claimed as being essential to the invention. Modifications to this are familiar to the person skilled in the art.

Claims

claims:

1. A process for processing animal meal into fuel, in particular for industrial combustion plants, characterized in that the animal meal is mixed with at least one additive and is subjected to a pressure treatment, the pressure treatment preferably being carried out by rolling or shaping, in particular briquettes or pellets.

2. The method according to claim 1, characterized in that the mixing of the animal meal with the at least one additive using reduced compared to atmospheric pressure

Printing takes place.

3. The method according to any one of the preceding claims, characterized in that a carbon-containing and / or mineral and / or metal-containing substance, in particular coal dust and / or sawdust and / or gypsum and / or cellulose and / or rejects and / or deinking sludge and / or sewage sludge and / or plastic and / or denaturing agent and / or denaturant and / or metal dust is used.

4. The method according to claim 3, characterized in that metal dust or a mixture, in particular alloy or solution, of various metal dusts in a quantity range of 0.5 vol.% To 4 vol.%, Preferably in the range from 1.9 vol.% To 3.6 vol.% And particularly preferably in the range from 2.8 vol. To 3.1 vol. % is added to a mixture to be compressed.

5. The method according to any one of the preceding claims, characterized in that the total amount of additive in a quantity range from 0.5 vol.% To 20 vol.%, Preferably in the range from 1.5 vol.% To 18 vol. % and particularly preferably in the range from 3% by volume to 15% by volume is added to the mixture to be pressed.

6. The method according to any one of the preceding claims, characterized in that a fluid, preferably water, is added to the mixture to be pressed.

7. The method according to any one of the preceding claims, characterized in that the mixture to be pressed using a pressure in the range from 15 bar to 250 bar, preferably in the range from 25 bar to 200 bar and particularly preferably in the range from 30 bar to 180 bar is rolled or pressed to form pellets and / or bricks.

8. Solid fuel based on organic materials, especially for industrial combustion plants. for example power plants. Kilns or incinerators, characterized in that the solid fuel consisting essentially of animal meal and egg zurnindest consists _¬ nem aggregate.

9 ^. Solid fuel according to claim 8, characterized in that the solid fuel as an additive is a carbon-containing and / or mineral and / or metal-containing substance, in particular

Coal dust and / or sawdust and / or gypsum and / or cellulose and / or rejects and / or deinking sludge and / or sewage sludge and / or plastic and / or denaturing agents and / or denaturants and / or metal dust.

10. Solid fuel according to claim 9, characterized in that in the solid fuel a concentration of metal dust or a mixture, in particular alloy or solution, of various metal dusts in a quantity range from 0.5 vol.% To 4 vol.%, Preferably in the range of 1.9% by volume to 3.6% by volume and particularly preferably in the range from 2.8% by volume to 3.1% by volume.

11. Solid fuel according to one of claims 8 to 10, characterized in that in the solid fuel a total concentration of additive in the range from 0.5 vol.% To 20 vol.%, Preferably in the range from 1.5 vol. % to 18% by volume and particularly preferably in the range from 3% to 15% by volume.

12. Solid fuel according to one of claims 8 to 11, characterized in that the at least one additive is intimately mixed with the animal meal.

13. Solid fuel according to one of claims 8 to 12, characterized in that the solid fuel is a fluid, in particular

Contains water and / or a carbon-containing, in particular fire-accelerating, fluid.

14. Solid fuel according to one of claims 8 to 13, characterized in that the solid fuel is a pressing.

15. Solid fuel according to one of claims 8 to 14, characterized in that the solid fuel is a pellet.

16. Solid fuel according to one of claims 8 to 14, characterized in that the solid fuel is a bricket.

17. Solid fuel according to one of claims 8 to 13, characterized in that the solid fuel is present after storage in a powdery, granular or pulpy consistency.

18, solid fuel, characterized by a composition according to ei ^¬ nem of claims 8 to 17, so that the Protei ^¬ contained therein ne of the meal in the combustion safely be destroyed and are contained by the combustion either in the exhaust air flow in the ash such proteins ,