EP2807239A1

EP2807239A1 - Product made from dried animal waste material, in particular used as a biofuel, and method for producing same

Info

Publication number: EP2807239A1
Application number: EP14707927.1A
Authority: EP
Inventors: Agnès KORN
Original assignee: Aksea Sarl
Current assignee: Aksea Sarl
Priority date: 2013-04-08
Filing date: 2014-02-25
Publication date: 2014-12-03
Also published as: WO2014167195A1; FR3004191A1

Abstract

The present invention concerns a product made from dried waste material from equine animals, characterised in that it comprises only wood residue amalgamated with said dried waste material. This product can be used, in particular, as a fuel. It is economical and environmentally friendly. It allows animal bedding made from wood residue to be recycled.

Description

PRODUCT BASED ON DRY MATTER ANIMAL DEJECTION, IN PARTICULAR AS BIOCOMBUSTIBLE,

The invention relates to a product based on dried animal excrement matter of the equine type, in particular to provide a natural fuel with a high calorific performance.

The invention will be more particularly described with respect to a horse dung product, without being limited thereto. Other types of animal dung can be used.

The product of the invention is preferably in the form of logs, sticks, pellets or granules, without being limited thereto.

The product is more particularly used as a fuel for heating, but may have other properties for being used for other uses, such as an insulation product including acoustic. In this latter application, it is for example integrated with insulating panels.

Today, fossil fuels that are used as heating fuels are dwindling and are becoming increasingly expensive. For several years, we have been looking for substitutes for conventional heating fuels.

Among the alternative solutions currently proposed, anaerobic digestion or the combustion of biomass, such as that of plants or of various products resulting from livestock farming activities, is particularly valued. For example, it is known to recycle horse manure to make a fuel. Patent application WO2007 / 093143 proposes fuel pellets made from dried horse manure.

It should be remembered that the horse manure is derived from clean straw which is at the base of horse bedding, and which has been soiled by manure (liquid and solid) from equines.

The manufacturing method described in the aforementioned patent application is however tedious to implement, including many steps, including several drying steps and a humidification step once the material has been dried, in order to proceed to the formatting of the final product.

Other documents of the prior art, such as patent applications EP0985723, DE102007049128 or US201 10162264, provide manure-based fuel products and which after drying are added wood chips. However, these products are made from manure, that is to say from straw and dung. It is then necessary after one or more stages of drying to add wood to constitute a fuel. The valuation of animal waste in the form of biofuel is therefore a very interesting way. However, the products and manufacturing process proposed today do not favor the development of the sector. The object of the invention is therefore to propose a product derived from animal manure so as to valorize it, this product nevertheless being different from the prior art and generating a simplified manufacturing process, while leading to various uses, and not exclusively as fuel.

To this end, the subject of the invention is a product based on dried animal excrement matter, of the equine type, comprising wood residues characterized in that it exclusively comprises wood residues amalgamated with said dried excrement matter. and that the wood residues and the dried excrement materials are the exclusive components of soiled bedding of animals, the litters being made (exclusively) of wood residues. In particular, litters are made of untreated wood residues. Preferably, the litters are made of softwood residues.

"Wood residues" means wood chips, petals or wood fibers from the processing of wood.

Thus, if the prior art discloses a product based on manure (mixed straw and dung), the invention proposes a product exclusively made of a mixture of wood chips (and not straw) and dung. The product of the invention therefore excludes the use of manure consisting of straw stained with animal dung such as dung.

This new product assumes that animal litter is no longer based on straw but wood chips. While this will change the habits in many equestrian complexes, but this has an advantage certain as to the valuation of wood from its first transformation. The applicant thus proposes a process for both recovery of wood residues (use for litter) and recycling (soiled litter).

The product of the invention is particularly advantageous because it allows a manufacturing process whose number of steps is extremely limited.

In addition, it involves a first recycling well upstream, that of wood residues, especially in sawmills or wood furniture manufacturing plants for example, to provide litter to animals, especially equines.

Then, the wood residues thus undergo, after using the litter, a second recycling to be converted into a product of the invention that can be used as a biofuel or acoustic insulation.

For example, a racetrack can generate about a ton and a half per day of soiled litter, which can be recycled. A ton of manure at 45% moisture represents 700 kg of dry matter of the product of the invention which can then be compacted to the dimensions and shape desired for example to make logs.

In addition, the use of wood chips as bedding has many advantages over straw, including:

- The wood chips are very absorbent, which contributes to the comfort of the horse, the box remaining dry and odorless, and for a long time;

- Once dusted, the wood chips are particularly well tolerated by horses, which when they have difficulties breathing are much less inconvenienced than with straw. It has indeed been shown that horses are becoming more and more allergic to straw because of the numerous chemical treatments imposed on crops;

- The conditioning of wood chips results in easier storage than that of straw;

- The cleaning of the boxes is much faster;

- The volume of soiled litter is less to recycle than that of straw.

Therefore, the product of the invention made based litter stained wood residues exclusively (and not straw-based) thus has many advantages and allows a recycling of wood completely upstream of the wood utilization chain, Sawmills and factories manufacturing wood-based industrial products such as furniture.

Finally, when the product of the invention is used as a fuel, the ash resulting from the combustion can advantageously be recycled as fertilizer.

As a result, the applicant is proposing an innovative way of using wood residues that had never previously been proposed, the use of animal litter which, once soiled, is transformed into a recycled product, the same product once used as fuel can be further recycled.

According to a characteristic of the product of the invention, the wood represents 60 to 90% of the mass of the product while the waste materials represent 40 to 10% of the mass, the mixture of wood and materials dejection representing 100% of the mass, preferably the proportions being of the order of 90% for wood and 10% for excrement materials. The estimation of the proportions is carried out at the time of grinding where the "pellets" of dung are ejected by the machine.

Preferably, the product according to the invention has a residual moisture content of not more than 15%, especially between 5 and 15%, preferably between 9 and 12%. The product is densified, having been dehydrated and compacted. It has very slow combustion properties and has a lower heating value (PCI) of the order of 4000 to 5000 kW / ton, three to four times more than conventional wood. Advantageously, the product according to the invention is present in the form of logs, sticks, pellets or pellets, in particular to constitute a heating fuel.

In particular, this product can replace firewood. It is suitable for any type of system using wood as fuel, stove, fireplace with particular insert, boiler, wood stove, etc.

This solution is much more economical and ecological compared to current solutions such as oil or gas, wood combustion releasing much less C0 ₂ .

This solution is also much more ecological compared to traditional firewood, avoiding the massive felling of trees, while being very efficient in its function. Surprisingly, the applicant has demonstrated that the product of the invention used as a fuel burns slowly and has a heating value four times higher than cutting wood.

In addition, at equal performance, the storage volume is much lower, especially divided by four. The subject of the invention also relates to the method of manufacturing said product. The method comprises a step of grinding wood residues soiled with animal excrement materials to form a mixture, a dehydration step of the mixture, a shaping step to provide a product ready for use.

The raw material in the grinding stage consists exclusively of wood residues and animal dung from litters soiled with animals, the litter being made of wood residues. The manufacturing process of the finished product does not include any step of adding wood residues to soiled wood residues.

Advantageously, the raw material is brewed before the grinding step.

The process comprises only one dehydration step and this grinding step is prior to dehydration.

Grinding involves grinding the soiled bedding to provide a substantially homogenous ground mixture for dewatering. The Soiled litter does not need to undergo a previous dehydration step.

Before the implementation of the method, soiled litter of animals, in particular equines, were of course collected.

According to another characteristic, the method of manufacturing said product comprises before the dehydration step, a step of measuring the moisture content of the ground mixture.

According to another characteristic, the method of manufacturing said product makes it possible, at the end of the dehydration step, for the mixture to comprise a residual moisture content of between 5 and 15%, preferably between 9 and 12%. Advantageously, the dehydration step of said process is carried out by heating the ground mixture in a chamber coupled to a dehumidifier, in particular the heating temperature being between 25 and 40 ° C. In another embodiment, the dehydration step is carried out by heating the ground mixture by means of infrared radiation heating means, in particular the mixture running on a carpet in a tunnel provided with said heating means whose temperature is between 75 and 100 ° C.

In the context of fuel utilization, the dehydration step is directly followed by the shaping of the product to be ready for use.

The shaping step in the process of the invention is carried out by compacting the ground and dehydrated mixture by means of a press. In in particular compacting is carried out under a pressure of the order of 150 bar, ie of the order of 150 kg / cm ² .

The high-pressure compaction of the dehydrated material is sufficient to produce the densified product without having to add glue or other additive-type bonding element.

The press will be adapted to the shape of the product to be delivered. The densified product obtained can for example be in the form of sticks, pellets or pellets.

A preferred example of a product of the invention relates to use as a fuel.

In an alternative use of the product, the product, once the collection, grinding and dewatering steps have been carried out, can be used as an insulation product, in particular an acoustic product, for example by being intended to be integrated with insulating panels. .

Finally, the invention therefore proposes the use of animal litter consisting exclusively of wood residues, characterized in that litter once soiled by animal dung is harvested and transformed into a recycled product made exclusively from soiled litter. According to this use, the recycled product is used in the form of fuel or insulating material.

The present invention is now described with the aid of an exemplary embodiment, only illustrative and in no way limiting the scope of the invention. The product of the invention is intended as an example to be used as a heating fuel. The product of the invention comprises wood chips amalgamated with dried animal excrement material such as horse dung.

The product is derived from the recycling of litter contaminated with equines based exclusively on untreated wood residues. "Wood residues" means wood chips, petals or wood fibers.

The product obtained by the process of the invention which will be described below comprises exclusively dung and wood chips in the following proportions relative to the mass of the product:

- 60 to 90% of wood;

- 40 to 10% dung;

the mixture of wood and dung representing 100% of the mass.

Preferably, the proportions are of the order of 90% for wood and 10% for excrement materials.

The dung-wood composition was crushed, dehydrated and compacted to provide a densified product having a density of the order of 1000 kg / m ³ .

The product has a residual moisture of at most 15%, preferably less than 12%, in particular between 9 and 12%. The product, although derived from animal waste, does not smell and does not release when burned, at least if no additive odor in the manufacturing process has been added. Very advantageously, the product of the invention has very slow combustion properties and has a lower heating value (ICP) of the order of 4000 to 5000 kW / ton, three to four times more than conventional firewood. Preferably, the wood used is softwood. This provides animal litters that are more comfortable than hardwood litters. In addition, in a heating use, the softwood delivers more heat than other types of wood. The manufacturing process is now described.

The process of the invention comprises the main steps of grinding, drying and shaping. Beforehand, the raw material, litter soiled with equines, is harvested.

The collected material presents a variable humidity rate according to the seasons and the mode of storage in the stables before use. This moisture content varies between 25 and 44% of the total mass of material.

If the harvested material is not immediately treated according to the method of the invention, it is then stored in a suitable place. The material is kneaded regularly to limit the methanation due to fermentation natural that takes place in any manure. The brewing is done by any appropriate means of known type.

The process of the invention begins with a step of grinding the collected material and amalgamated to deliver a substantially homogenous ground mixture.

In fact, the collected material has residues of wood and organic fibrous matter, the dung, whose size varies. In particular, the wood residues have a length of between one and four centimeters for a thickness of 0.5 to 1 mm, whereas the dung may vary between 2 and 10 cm in diameter.

Grinding is obtained by any known means, such as a grinding mill type machine.

The ground mixture is advantageously in the form of aggregates, in particular of the diameter of about 1 millimeter thick by 2 to 5 cm long and 1 cm wide.

Before starting, the second main step of the method which is drying, the moisture content of the ground mixture is measured in the usual manner, and with a known type of apparatus measuring the moisture content. The analysis of the moisture content of the ground mixture makes it possible to determine the operating conditions of the dehydration (drying) stage so as to obtain a crushed and dried mixture having a residual moisture of at most 15%, preferably between and 12%, more specifically between 9 and The moisture content of the crushed and dried product is measured in the same way as before grinding, by the same apparatus.

Below a moisture content of 9%, the applicant has highlighted that the product used as a fuel is not efficient because burning far too quickly.

Above a moisture content of 12%, the applicant has shown that the product has a tacky feel that makes handling unpleasant, and used as a fuel makes its combustion difficult and less efficient.

A residual moisture content between 9 and 12% makes it possible to obtain a high performance fuel with regard to its lower heating value (ICP).

The dehydration step that follows the measurement of the moisture content is done in one go. It is carried out continuously, possibly with intermediate measurements of the moisture content. Thus, unlike the method of the prior art which, for straw, requires several dewatering phases, the method of the invention requires only one.

Dehydration is performed by drying means.

In one embodiment, the drying is obtained by heating the ground mixture in a closed chamber and coupled to at least one industrial dehumidifier. The heating temperature, internal temperature of the enclosure, is between 25 and 40 ° C. The dehumidifier is used to evacuate the water vapor. The drying time depends on the amount of mixture to be dried, the type of heater, the heating temperature, the type of means for evacuation of water vapor.

Preferably, the dehumidifier used can ensure an absorption of the order of 300 to 350 liters of water per hour.

For example, 24 hours will dry 15 m ³ of ground mixture.

In another embodiment, the dehydration step is carried out by heating the mixture by infrared radiation heating means.

The crushed mixture is for example placed on a conveyor belt and is conveyed in a tunnel with infrared heating. The mixture is spread over a thickness of about 2 cm. The mixture travels under the infrared radiation over a length of, for example, 5 m, and at a speed notably comprised between 1 and 2 meters / minute.

The temperature delivered by the infrared is in particular between 75 and 100 ° C.

Finally, the method comprises a shaping step of the milled and dried mixture to give it the desired shape for use. The mixture thus dried is compressed under high pressure. It is placed in particular in a press, such as for example a press of the known type delivering densified wood briquettes. The mixture is compressed in particular at a pressure of 150 bar, ie of the order of 150 kg / cm ² .

The product example described above relates to use as fuel but is not limited thereto.

Claims

1. A product based on equine animal-derived dried animal waste material comprising wood residues, characterized in that it exclusively comprises wood residues amalgamated with said dried excrement materials and that the wood residues and Dried excrement are the exclusive components of soiled bedding of animals, litter being made of wood residues.

2. Product according to claim 1, characterized in that the wood litter residue is softwood.

3. Product according to claim 1 or 2, characterized in that the wood represents 60 to 90% of the mass of the product while the excrement materials account for 40 to 10% of the mass, the mixture of wood and excrement materials representing 100% of the mass, preferably the proportions being of the order of 90% for wood and 10% for excrement materials.

4. Product according to any one of the preceding claims, characterized in that it has a residual moisture content of between 5 and 15%, preferably between 9 and 12%.

5. Product according to any one of the preceding claims, characterized in that it is in the form of a densified product, having been dehydrated and compacted.

6. Product according to any one of the preceding claims, characterized in that it is in the form of logs, sticks, pellets or pellets, in particular to form a heating fuel.

7. Product according to any one of the preceding claims, characterized in that it is used as an insulation product in particular acoustic, in particular being intended to be integrated with insulating panels.

8. A method of manufacturing a product according to any one of claims 1 to 7, comprising a step of grinding a raw material made of wood residues and animal waste materials to form a mixture, a dehydration step a step of shaping the mixture to provide a ready-to-use product, characterized in that the raw material in the grinding stage consists exclusively of wood residues and animal excrement from litters soiled with animals , the litters being made of wood residues.

9. Method according to claim 8, characterized in that the raw material is brewed before the grinding step.

10. The method of claim 8 or 9, characterized in that it comprises only one dehydration step after the grinding step.

1 1. Method according to one of claims 8 to 10, characterized that it comprises before the dehydration step, a step of measuring the moisture content of the mixture having been ground.

12. Method according to one of claims 8 to 1 1, characterized in that the dehydration is carried out by heating the ground mixture in an enclosure coupled to a dehumidifier, in particular the heating temperature being between 25 and 40 ° C.

13. Method according to one of claims 8 to 12, characterized in that the dehydration is carried out by heating the ground mixture, by means of infrared radiation heating means, in particular the mixture moving on a carpet in a tunnel provided with said means of heating whose temperature is between 75 and 100 ° C.

14. Method according to one of claims 8 to 13, characterized in that the dehydrated mixture is compacted and shaped, in particular the compaction being carried out under a pressure of the order of 150 bars.

15. Use of animal litter consisting exclusively of wood residues, characterized in that litter once soiled by animal dung is harvested and transformed into a recycled product made exclusively from soiled litter.