FR2818657A1 - Treatment of animal-derived meal for use as a solid fuel constituent involves mixing the meal with a carbonaceous powder and agglomerating the mixture to form solid particles - Google Patents

Abstract

Treatment of animal-derived meal involves intimately mixing the meal with a carbonaceous powder such that the mixture contains 5-40% of the carbonaceous powder, and forming solid particles from the mixture by agglomeration under pressure. The carbonaceous powder wholly or partly comprises coal, lignite, coke, petroleum coke, peat, or carbonaceous residue. A binder is mixed with the mixture of the meal and the carbonaceous powder, and the composition is cold-molded under an elevated pressure of 50-150 bars. The binder comprises hydraulic lime and/or fibrous clay. The fibrous clay is preferably an attapulgite-type clay. Sodium tripolyphosphate in amount 0.05-0.3% can be incorporated into the mixture. 5-10% of clay can be added to the mixture in order to provide a bactericidal effect and an effluent-fixation effect during combustion. The granules are obtained by compression in an agglomeration machine. Independent claims are given for: (a) a product obtained by using the above process; and (b) an installation for the implementation of the above process, comprising weighing, mixing and agglomerating units.

Description

<Desc / Clms Page number 1>

PROCESS FOR THE PROCESSING OF ANIMAL FLOUR WITH A VIEW TO MAKING IT CONSUMABLE.

PRODUCT THUS OBTAINED AND MEANS OF IMPLEMENTATION
The invention relates to a process for transforming animal meal with a view, at least, to making it non-consumable, storable and reusable as common solid fuel.

 The invention also relates to the product obtained and to the means of implementation.

 Flours of animal origin have been used massively as food supplements in animal feed.

 These animal meals are a source of protein, making it possible to increase the lactation and muscle mass of cattle more quickly.

 Animal meal is produced from fish meat but also from animal meat.

 In recent years, it has become likely that these animal meals were the cause of spongiform encephalopathies.

 This observation led the authorities of various countries to take binding measures to prohibit their use in animal feed and systematically destroy the stocks.

 The problem of destruction of dead animals or slaughterhouse waste, etc., must also be resolved.

 Destruction is not a simple operation.

 For example, destruction systems consist of injecting flour in powder form into cement kilns.

graisses qui perturbent le bon fonctionnement des fours. Such a system is not very effective because animal meal produces

greases which interfere with the proper functioning of the ovens.

Indeed, the fat contained in these flours oozes at the top of the hearth and clogs the grates.

<Desc / Clms Page number 2>

Furthermore, the injection of animal flour in powder form is not conducive to good destruction and encounters difficulties in pneumatic transport by clogging of the circuits.

 Note that this also poses pollution problems because, when handling a site to another site, there is a risk of dust flight.

 Also, the ovens are designed to process materials of a predetermined size and not fines.

 Animal meal contains 10 to 30% fat which makes it difficult to store, grind and manipulate due to self-heating and clogging phenomena.

 This is why manufacturers are not in favor of this method of destruction.

 The invention relates to a process for transforming animal meal with a view to destroying it which overcomes these drawbacks, this process being characterized in that animal flour is mixed with carbon powder in proportions such that the mixture obtained contains 5 to 40% carbonaceous powder so as to obtain a homogeneous mixture of coal and flour and with this mixture solid granules are formed by agglomeration under pressure.

 The invention will be clearly understood with the aid of the description given below, by way of nonlimiting example, with regard to the drawing which schematically represents the various operating steps of the process.

 Referring to the drawing, we see that, to destroy animal meal, we proceed to a treatment of these meals.

 According to a characteristic of the invention: - animal flour 1 is intimately mixed with carbon powder 2 and possibly mineral materials in proportions such that the mixture obtained contains 5 to 40% carbon powder and, with this mixture, - solid pellets, pellets or briquettes are formed by pressure agglomeration.

<Desc / Clms Page number 3>

 The carbonaceous powder will consist of all or part of the following materials: coal, lignite, coke, petroleum coke, peat or carbonaceous residues.

 This agglomerated fuel makes it possible to: - collect the flours with guaranteed traceability fulfilling the pass requirements expressed by the Public Administration, - denature the flours by mixing and agglomeration with carbon and mineral materials making it completely impossible to reintroduce the flours thus processed in the livestock feed chain, - reducing by volume the volume of flour to be transported and destroyed, - improving the handling and storage of flour, - stabilizing the flour by reducing the specific surface area and adding mineral elements, - to promote the product thus obtained as a common solid fuel which does not require too significant a modification in the existing fleet of boilers (industrial, electric power plants, heating furnaces, cement manufacturers ...) and does not generate additional nuisances during of combustion.

 These agglomerates after solidification will be introduced into an oven, after possible grinding.

The advantage of such a system consists in that each agglomerate has a composition promoting combustion, this composition being able to be qualified as stoichiometric.

A homogeneous distribution of the carbonaceous powder with the flour must be obtained.

 Indeed, instead of introducing the flour in mass in a boiler while trying to obtain a reaction with the fuel contained in the boiler, each agglomerate behaves like an autonomous fuel.

 The most important point is that through the agglomeration is obtained a solid fuel with specific behavior.

<Desc / Clms Page number 4>

During the rise in temperature which can range from a few seconds to twenty minutes depending on the boilers, the oils and greases liquefying and gasifying, are trapped in the carbon matrix.

In fact, carbonaceous matter has a large internal specific surface, a function of its genesis, up to the qualities of activated carbon thus allowing a fixation of liquid or gas phase in its atomic and molecular structure.

 The addition of lime eventually allows chemical and bactericidal neutralization as well as fixing of sulfur and phosphorus and other mineral parts and metals in the ashes.

 This percentage will be between 5 and 20%.

 Thus, during the rise in temperature, the crystal lattice and the arrangement of the divided material are physically reinforced by viscous adhesion. The volatilization of oils, fats and materials contained in the carbon part allows a more perfect combustion than carbon alone or animal meal alone.

 Advantageously, during combustion, a kind of external shell is therefore formed which causes total combustion of the core of the granule.

 There is no accumulation of material in a part of the oven, which can then be rejected in nature.

 In order to complete the combustion, it may advantageously be incorporated sodium tripolyphosphate at the rate of 0.05% to 0.3% of the total mass.

 The agglomeration is carried out by compression by the use of agglomeration machines such as tangent wheel presses, briquetting piston presses or extrusion presses.

 Due to the abrasiveness of the materials used, the wearing parts of these machines can advantageously be produced in high-speed steel quality, that is to say HSS, for example, grade M2.

 In the case of piston or extrusion presses, under the effect of forces and deformations, the intimate mixture of flour and mineral matter increases by

<Desc / Clms Page number 5>

 temperature so that the fat in the flour melts slightly and forms a binder.

 Free or accelerated air cooling allows the granules to freeze.

 In another embodiment, to the intimate mixture of flour and mineral materials, a binder 3 is added and, after kneading, the composition undergoes cold molding under a high pressure of between 50 and 150 bars.

 One can also use a piston press such as those used for lignit briquettes.

 The binder can consist of hydraulic lime, molasses, a fibrous clay.

 This fibrous clay will be an attapulgit type clay.

 The clay will act as an absorbent.

 Hydraulic lime will have a fourfold function: - that of hydraulic binder, - that of bactericide, - that of fat stabilizer.

 - that of fixative in the ashes of molecules released by combustion such as sulfur, phosphorus, ... helping to reduce gaseous effluents.

 The product obtained will be composed of animal meal and mineral matter, intimately mixed in a proportion of 5 to 50% of total mineral matter by weight.

The flour processing unit will include the following functions: a) storage of animal meal and other materials used in the composition of the agglomerate (carbon, mineral products, binders, etc.), b) manufacture of the agglomerate, c) storage of solid fuel. a) Storage of animal meal:
Such an installation can be located

<Desc / Clms Page number 6>

 - either directly at the place of manufacture of the flours in which case they will be transformed, through a buffer hopper, continuously in the process described, - or at an independent place allowing the taking into account of several sites of manufacture of flours.

 This skid-mounted installation can also be transferred to agglomerate by campaigns in flour storage places.

 The animal meal to be destroyed transported by trucks (piggyback possibilities) in a dedicated standard bucket by an approved specialized transporter, is emptied into a pit and taken up by continuous transport for storage on the covered floor or in a dedicated hopper.

 The recovery is done by tractor loader on belt conveyor to go to the adjoining workshop.

The other materials are stored either on the ground (coal), or in a silo (powdery products) or in tanks (liquid products). b) Manufacturing workshop:
Its organization is articulated in three modules: - weight dosage, - mixing, - agglomeration. c) Storage of solid fuel:
The fuel is taken out on the agglomeration workshop conveyor: - either in storage silos with an adjoining boiler, - or ashore in an adjoining covered hall with a capacity of three months to deal with: on call from the boiler,. possible technical unavailability of the boiler,. a cyclical need for the elimination of animal meal (systematic slaughter, etc.).

 Regarding combustion:

<Desc / Clms Page number 7>

Le combustible est stocké dans les silos à l'entrée de la chaudière. Il est extrait sur convoyeur à bande et peut être orienté vers deux circuits : - un circuit de broyage inférieur à zu et introduction directe dans la chaudière par brûleur à air pulsé, - une incorporation dans le circuit principal de charbon avant broyage et combustion.

The fuel is stored in the silos at the entrance to the boiler. It is extracted on a belt conveyor and can be oriented towards two circuits: - a grinding circuit lower than zu and direct introduction into the boiler by forced air burner, - incorporation into the main coal circuit before grinding and combustion.

 When pulverized material is used, it is preferred to grind the granules. In fact, animal meal and mineral materials such as coal remain in bond with a homotetic effect (fractal geometry) and the combustion qualities remain.

 In addition, the carbon and the incorporated mineral matter have a self-grinding and unclogging effect.

Claims (11)

 CLAIMS 1. Process for transforming animal meal with a view to destroying it CHARACTERIZED in that: - animal flour (1) is intimately mixed with carbon powder (2) in proportions such that the mixture obtained contains 5 to 40% carbonaceous powder and with this mixture, - solid granules are formed by agglomeration under pressure.  2. Method according to claim 1 characterized in that the carbon powder consists of all or part of the following materials: coal, lignit, coke, petroleum coke, peat or carbon residue.  3. Method according to claim 1 characterized in that the granules are obtained by compression through agglomeration machines.  4. Method according to claim 1 characterized in that to the intimate mixture of flour and carbonated powder, a binder is added and, after kneading, the composition undergoes cold molding under a high pressure of between 50 and 150 bars.  5. Method according to claim 4 characterized in that the binder consists of hydraulic lime and / or a fibrous clay.  6. Method according to claim 1 characterized in that incorporates sodium tripolyphosphate at the rate of 0.05% to 0.3%.  7. Method according to claim 4 characterized in that the fibrous clay is a clay of the attapulgit type.  8. Method according to claim 1 characterized in that 5 to 20% of lime are added for a bactericidal effect and fixing of the effluents in the ashes during combustion.  9. Method according to claim 1 characterized in that the agglomeration means are made of high-quality steel, that is to say HSS

 grade M2.  10. Product characterized in that it is obtained using the process for transforming animal meal according to any one of claims 1 to 9. <Desc / Clms Page number 9>

9 11. Means for implementing the method according to any one of claims 1 to 9 characterized in that they include weighing means, kneading means and agglomeration means.