Classifications

• • C—CHEMISTRY; METALLURGY
  • C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
  • C12M—APPARATUS FOR ENZYMOLOGY OR MICROBIOLOGY; APPARATUS FOR CULTURING MICROORGANISMS FOR PRODUCING BIOMASS, FOR GROWING CELLS OR FOR OBTAINING FERMENTATION OR METABOLIC PRODUCTS, i.e. BIOREACTORS OR FERMENTERS
  • C12M21/00—Bioreactors or fermenters specially adapted for specific uses
  • C12M21/04—Bioreactors or fermenters specially adapted for specific uses for producing gas, e.g. biogas
• • C—CHEMISTRY; METALLURGY
  • C05—FERTILISERS; MANUFACTURE THEREOF
  • C05F—ORGANIC FERTILISERS NOT COVERED BY SUBCLASSES C05B, C05C, e.g. FERTILISERS FROM WASTE OR REFUSE
  • C05F17/00—Preparation of fertilisers characterised by biological or biochemical treatment steps, e.g. composting or fermentation
  • C05F17/90—Apparatus therefor
• • C—CHEMISTRY; METALLURGY
  • C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
  • C12M—APPARATUS FOR ENZYMOLOGY OR MICROBIOLOGY; APPARATUS FOR CULTURING MICROORGANISMS FOR PRODUCING BIOMASS, FOR GROWING CELLS OR FOR OBTAINING FERMENTATION OR METABOLIC PRODUCTS, i.e. BIOREACTORS OR FERMENTERS
  • C12M23/00—Constructional details, e.g. recesses, hinges
  • C12M23/34—Internal compartments or partitions
• • C—CHEMISTRY; METALLURGY
  • C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
  • C12M—APPARATUS FOR ENZYMOLOGY OR MICROBIOLOGY; APPARATUS FOR CULTURING MICROORGANISMS FOR PRODUCING BIOMASS, FOR GROWING CELLS OR FOR OBTAINING FERMENTATION OR METABOLIC PRODUCTS, i.e. BIOREACTORS OR FERMENTERS
  • C12M23/00—Constructional details, e.g. recesses, hinges
  • C12M23/36—Means for collection or storage of gas; Gas holders
• • C—CHEMISTRY; METALLURGY
  • C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
  • C12M—APPARATUS FOR ENZYMOLOGY OR MICROBIOLOGY; APPARATUS FOR CULTURING MICROORGANISMS FOR PRODUCING BIOMASS, FOR GROWING CELLS OR FOR OBTAINING FERMENTATION OR METABOLIC PRODUCTS, i.e. BIOREACTORS OR FERMENTERS
  • C12M23/00—Constructional details, e.g. recesses, hinges
  • C12M23/38—Caps; Covers; Plugs; Pouring means
• • C—CHEMISTRY; METALLURGY
  • C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
  • C12M—APPARATUS FOR ENZYMOLOGY OR MICROBIOLOGY; APPARATUS FOR CULTURING MICROORGANISMS FOR PRODUCING BIOMASS, FOR GROWING CELLS OR FOR OBTAINING FERMENTATION OR METABOLIC PRODUCTS, i.e. BIOREACTORS OR FERMENTERS
  • C12M23/00—Constructional details, e.g. recesses, hinges
  • C12M23/58—Reaction vessels connected in series or in parallel
• • C—CHEMISTRY; METALLURGY
  • C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
  • C12M—APPARATUS FOR ENZYMOLOGY OR MICROBIOLOGY; APPARATUS FOR CULTURING MICROORGANISMS FOR PRODUCING BIOMASS, FOR GROWING CELLS OR FOR OBTAINING FERMENTATION OR METABOLIC PRODUCTS, i.e. BIOREACTORS OR FERMENTERS
  • C12M29/00—Means for introduction, extraction or recirculation of materials, e.g. pumps
• • C—CHEMISTRY; METALLURGY
  • C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
  • C12M—APPARATUS FOR ENZYMOLOGY OR MICROBIOLOGY; APPARATUS FOR CULTURING MICROORGANISMS FOR PRODUCING BIOMASS, FOR GROWING CELLS OR FOR OBTAINING FERMENTATION OR METABOLIC PRODUCTS, i.e. BIOREACTORS OR FERMENTERS
  • C12M29/00—Means for introduction, extraction or recirculation of materials, e.g. pumps
  • C12M29/02—Percolation
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
  • Y02E50/00—Technologies for the production of fuel of non-fossil origin
  • Y02E50/30—Fuel from waste, e.g. synthetic alcohol or diesel
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
  • Y02P20/00—Technologies relating to chemical industry
  • Y02P20/141—Feedstock
  • Y02P20/145—Feedstock the feedstock being materials of biological origin
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
  • Y02P20/00—Technologies relating to chemical industry
  • Y02P20/50—Improvements relating to the production of bulk chemicals
  • Y02P20/59—Biological synthesis; Biological purification
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
  • Y02W30/00—Technologies for solid waste management
  • Y02W30/40—Bio-organic fraction processing; Production of fertilisers from the organic fraction of waste or refuse

Definitions

• the invention relates to a waste treatment plant, as well as to a method for implementing this installation.
• the invention relates to the treatment and energy recovery of any solid waste, non-toxic and containing organic materials.
• the main source of such waste is the collection of garbage and so-called vegetable or green waste, generated by agriculture or the maintenance of parks and gardens.
• composting has a very low added value because compost has virtually no market value, except in countries with no quality agricultural land.
• anaerobic digestion allows a significant recovery of organic waste, because it makes it possible to produce biogas.
• the latter constitutes a renewable energy, whose energy potential is high since it contains a substantial fraction of methane, and whose carbon balance is very favorable.
• the treatment of the organic fraction of waste is mainly oriented towards energy recovery. Indeed, the latter presents a much more economically attractive, while being environmentally equivalent compared to the composting industry.
• the methanogenesis sector uses the biogas thus produced as a fuel in electric generators operating on gas, or injects this biogas into existing town gas distribution networks.
• This type of recovery can only treat the fermentable part of the waste to be recovered.
• the thermal recovery of this ultimate waste is not feasible because it is technically complex and therefore too expensive to be economically viable.
• Methanogenesis occurs naturally in garbage dumps, but over very long periods of time (up to 20 years).
• Methanogenesis is better implemented in a methanizer, which is a small reactor equipped with waste brewing means.
• the treatment time is relatively low, but the methanizer requires, to be effective, a prior separation of the organic fraction, which is very complex and expensive, bringing the cost of the methanization of solid waste to economically prohibitive levels. .
• the incineration process uses heat produced in various devices, such as steam turbines or heat networks. This recovery is, however, effective only on the dry part of the waste to be recovered, such as fibrous or plastic materials.
• the methanogenic potential of the wet fermentable fraction is not valorised, which greatly degrades the efficiency of the thermal recovery of the dry fraction and makes the operation of incinerators very complex.
• EP 1 767 500 which relates to a dry fermentation plant.
• receiving compartments for the waste to be treated which can be selectively covered by means of a waterproof membrane.
• the technical solution described in this document does not ensure optimum treatment of all types of waste, in particular the wet fermentable fraction thereof.
• a digester for the production of biomethane from organic substances.
• This digester comprises a fixed base and an upper vessel, which delimits several compartments and can be rotated around its central hub.
• FR 2 543 159 also teaches the skilled person to fully immerse each compartment, indicating a minimum level 31. This teaching diverts the skilled person to use any recirculation of liquid, as in the present invention . Indeed, such a recirculation is totally incompatible with the complete immersion of the compartments provided for in FR 2 543 159. Moreover, this document does not provide any clear technical instruction to those skilled in the art as regards the emptying of each compartment. In this regard, it will be recalled that one of the objectives of the present invention is precisely to provide a satisfactory solution to the technical problem of emptying large compartments. Finally, the central hub of FR 2 543 159 is also immersed while being movable in rotation. These The features are totally incompatible with providing a common functional space, according to an advantageous feature of the present invention.
• an object of the present invention is to overcome, at least partially, the disadvantages of the prior art mentioned above.
• Another object of the invention is to provide an installation and a process which allows efficient treatment of both the moist fermentable fraction and the non-fermentable dry fraction of the waste.
• Another object of the invention is to propose such a method, which is relatively simple to control and which allows a reasonable processing time.
• Another object of the invention is to provide such an installation, which has a relatively simple structure and involves relatively low operating costs.
• Another object of the invention is to provide such an installation, which allows gravity filling and convenient emptying of waste for ultimate recovery.
• the above objectives are achieved by means of a solid waste treatment plant containing organic matter, in particular household waste and / or vegetable waste, for producing biogas and recovering the biogas produced.
• installation comprising at least two compartments, the volume of each compartment being greater than 1000 (thousand) cubic meters, as well as means of separation between these compartments, impervious to both gases and liquids, each compartment comprising: an interior volume for receiving the waste to be treated, presenting an opening for the admission of waste;
• peripheral walls bordering this interior volume
• the installation further comprising at least one gas and liquid-tight cover capable of covering at least one compartment;
• said installation comprises means for collecting a gaseous fraction, originating at least in part from the decomposition of the waste, in that each compartment defines an accumulation zone of a liquid fraction, originating at least in part decomposition of the waste, and in that the installation comprises circulation means adapted to circulate this liquid fraction from the accumulation zone to the interior receiving volume.
• the volume of each compartment is greater than 2000 (two thousand) cubic meters, in particular greater than 8000 (eight thousand) cubic meters, preferably greater than 12000 (twelve thousand) cubic meters.
• the volume of each compartment is less than 50000 (fifty thousand) cubic meters, in particular less than 40000 (forty thousand) cubic meters, preferably less than 25000 (twenty-five thousand) cubic meters.
• the installation shall comprise at least three (3) compartments, in particular at least four (4) compartments.
• the installation comprises a maximum of sixteen (16) compartments, in particular a maximum of twelve (12) compartments, preferably a maximum of eight (8) compartments
• the accumulation zone of the liquid fraction is a gravity accumulation zone.
• the accumulation zone by gravity is delimited by a bottom of the installation, inclined relative to the horizontal.
• the circulation means are adapted to circulate this liquid fraction from the accumulation zone to the upper part of the interior receiving volume
• the circulation means comprise, for each compartment, pumping means, located in the vicinity of the zone d accumulation, transfer means as well as distribution means in the interior receiving volume.
• the collection means comprise, for each compartment, at least one tubular collection assembly, which is placed in the internal volume of receiving, and a collector in communication with each tubular collector assembly.
• the installation comprises a common functional space, provided in the vicinity of all the compartments.
• the common functional space is central and the compartments extend to the periphery of this functional space, which defines a portion of the peripheral walls of at least a portion of the compartments.
• the separating means comprise separating walls extending radially from the central common functional space.
• At least one compartment is a so-called service compartment, which opens directly into the common functional space.
• the means for transferring the liquid fraction comprise means for controlling at least one parameter of the liquid fraction present in each compartment.
• the means for transferring the liquid fraction extend partly outside the compartment, in particular in the common functional space,
• a collector of the gaseous fraction which is common to several compartments and which extends partly to the outside of the compartment, in particular in the common functional space.
• N T * X / (V * entering), WHERE
• T is the duration of the internal cycle of a compartment, from the beginning of the filling phase until the end of the emptying phase (expressed in number of reference periods);
• X is the tonnage of waste entering the facility (expressed in tonnes per reference period);
• V is the average volume of the compartments of the installation
• dentrant is the average density of waste entering the facility.
• the subject of the invention is also a process for implementing a waste treatment plant containing organic materials, in particular household waste and / or vegetable waste, for producing biogas and recovering the biogas produced, as shown here. above, this method comprising, for each compartment, the following steps:
• the cover which is impervious to both gases and liquids, is placed above the bulk of waste so as to make the internal volume substantially watertight; at least partial anaerobic digestion of the fermentable part of the waste is carried out so as to produce a gaseous fraction as well as a liquid fraction; during at least part of the anaerobic digestion step, at least a portion of the liquid fraction is extracted from the accumulation zone and at least a portion of the liquid fraction thus extracted is introduced into the waste mass; at the end of the digestion step, the residue of the waste mass is evacuated from the interior volume.
• the waste to be treated is lacerated so as to transform a major part of this waste into strips, the largest dimension of which is advantageously greater than 5 centimeters, in particular to 10 centimeters, and the smallest dimension is advantageously between 2 and 5 centimeters.
• At inf ((V * entering) / X; T / N), WHERE
• X is the tonnage of waste entering the facility (expressed in tonnes per reference period);
• V is the average volume of the internal volume of waste reception from the compartments of the installation
• dentrant is the average density of waste entering the facility;
• T is the duration of the internal cycle of a compartment, from the beginning of the filling phase until the end of the emptying phase (expressed in number of reference periods);
• N is the number of compartments constituting the installation.
• the extracted liquid fraction is analyzed so as to access at least one parameter of this liquid fraction, and at least a portion of this extracted fraction is eliminated in the case where it has at least one parameter whose analyzed value is outside a set range.
• the anaerobic digestion step is controlled so as to reach a predetermined digestion rate of the degradable organic fraction initially present in the waste mass, this content being between 50 and 95%, preferably between 70 and 90% .
• the gaseous fraction produced in each compartment is extracted and the methane content contained in this gaseous fraction is measured in real time.
• the recirculation of the liquid fraction can be interrupted and the drying phase of the residual waste can be started.
• the duration of the anaerobic digestion step is between 12 and 72 months, especially between 30 and 60 months.
• the anaerobic digestion step is carried out so as to break down at least
• At least a portion of the extracted liquid fraction is introduced into the waste mass, so as to maintain the relative humidity of this mass of waste at a value of between 20% and 70%, preferably between 40% and 60%.
• at least a portion of the generated biogas is sent to a device for producing energy, in particular mechanical energy, such as a motor or a turbine.
• a step is taken to dry the waste mass, so as to lower the relative humidity of this mass of waste to below 20%, preferably below 10%.
• dry residue is obtained at the end of the drying step and at least a portion of this residue is thermally recovered, in particular in a solid fuel boiler or other combustion device.
• dry residue is meant a mass of waste whose liquid mass is less than 20% of the mass of the dry matter.
• the subject of the invention is a method of dimensioning a waste treatment installation such as above, in which the minimum number (N) of compartments of the installation is determined by the following formula:
• N T * X / (V * entering), WHERE
• T is the duration of the internal cycle of a compartment, from the beginning of the filling phase until the end of the emptying phase (expressed in number of reference periods);
• X is the tonnage of waste entering the facility (expressed in tonnes per reference period);
• V is the average volume of the compartments of the installation
• dentrant is the average density of waste entering the facility.
• the waste treatment plant allows the separate energy recovery of fermentable and non-fermentable fractions of solid waste. Note further that this facility is able to operate effectively, without the need for physical separation prior to the two aforementioned fractions.
• the waste is first treated by anaerobic digestion of its fermentable organic fraction, leading in particular to the production of biogas.
• This fermentable fraction thus disappears from the internal volume of the treatment compartment, leaving a residue with high calorific value, recoverable thermally at the end of the overall treatment process.
• This residue has the characteristics of a solid recovery fuel, or CSR, which allows its thermal recovery by any combustion system and recovery of the heat thus produced.
• Waste Apart from the filling, compacting and emptying of the compartments, the waste remains substantially static in the installation. This is advantageous, in particular because the compartment does not have to be equipped with brewing means, which are of a high cost and entail substantial operating costs. Waste makes the subject of a purely biochemical treatment, of a duration determined precisely according to the rate of anaerobic digestion of the organic compounds present in the massive waste.
• the installation according to the invention makes it possible to reach optimum efficiency conditions, with a view to a satisfactory recovery of the waste by methanogenesis.
• the invention firstly provides conditions for optimizing the generation of methane.
• the recirculation of the leachates namely the liquid fraction
• the grinding of the waste prior to their entry into the compartment, provides a targeted particle size, which improves the efficiency of methanogenesis.
• the invention also provides conditions for optimizing the capture rate of generated biogas.
• the presence of capture networks in each compartment is particularly advantageous.
• the cover ensures the sealing of each compartment during the anaerobic digestion phase.
• the installation makes it possible to combine all the favorable conditions for methanogenesis and the capture of generated biogas. Under these conditions, one can realistically aim for a digestion of more than 80% of the biodegradable organic fraction during the five years following the anaerobic conditioning of the waste treated by this installation.
• the invention constitutes a judicious compromise between the respective solutions proposed by the methanizers and the discharges.
• the installation according to the invention is devoid of particular waste brewing means, so that its structure is less expensive than that of the methanizers.
• This facility also has a volume of waste treatment that is much higher than that of the methanizers.
• the invention has specific advantages over discharges.
• the waste can be loaded and emptied more conveniently than in the context of a landfill.
• the invention allows a very short total treatment time compared to the complete life cycle of a discharge, which is
• the invention makes it possible to remedy the drawbacks related to the teaching of EP 1 767 500.
• the circulation of the liquid fraction in the waste mass makes it possible to keep the latter at a humidity level. optimal. Under these conditions, the methanogenic potential of the wet fermentable fraction can be satisfactorily valued.
• Figure 1 is a perspective view illustrating a waste treatment plant according to the invention.
• Figure 2 is a top view illustrating the installation of Figure 1.
• Figures 3 and 4 are perspective views of a compartment belonging to the installation of Figures 1 and 2, respectively illustrating the gas sensing means, and the liquid circulation means equipping the compartment.
• FIG. 5 is a sectional view of the compartment of FIGS. 3 and 4, along line V-V in FIG. 2.
• Figure 6 is a perspective view of the compartment of Figure 5, at an angle different from Figures 3 and 4, with tearing along the line V-V.
• the installation according to the invention essentially comprises a central, centrally located functional space, a plurality of compartments extending radially from this common functional space, as well as gas collection means and liquid circulation means.
• the common functional space 1 is hollow and has a polygonal shape, seen from above. It rests on a base 2, also polygonal, which has radial dimensions larger than those of this space.
• the number of sides of the functional space corresponds to the number of compartments, which is provided with the installation.
• Each peripheral wall 1A to 1F of the functional space corresponding to one side of the latter, forms a first lateral wall of a respective compartment. From each corner of the functional space, namely each intersection between two consecutive sides, a respective radial wall 3A to 3F extends outwardly. Two consecutive radial walls 3A and 3B, 3B and 3C, 3F and 3A, form two other side walls of a respective compartment.
• the constituent material of the walls 1A to 1F, of the base 2, as well as of the walls 3A to 3F, advantageously has the following characteristics:
• a preferred material is, for example, concrete.
• metal walls or earthen slopes covered with waterproof geomembranes are also used.
• the installation according to the invention comprises six receiving and waste treatment compartments, which are assigned references 4A to 4F.
• the structure of the compartment 4A will be presented in greater detail, it being understood that the other compartments have a similar structure.
• the compartment 4A has a bottom 10, which is formed in part by the base 2.
• this base is advantageously concreted.
• the outer part 1 1 of the bottom, peripheral to this base, is advantageously waterproofed by any suitable coating, in particular thanks to a geo-membrane.
• the bottom surface is slightly inclined, namely that its altitude increases from the junction with the functional space 1. This allows the liquid to accumulate, by gravity, in a zone Z delimited by this surface.
• the slope ratio between this surface and the horizontal, denoted a in FIG. 5, is advantageously between 1 and 2 ° (degrees).
• the bottom 10 is extended, radially outwardly, by an enclosure wall 12 which connects the free ends of the two side walls 3A and 3B, and which defines an inclined ramp. If ⁇ is the angle formed by the surface of this wall 12 and the horizontal, this angle is advantageously between 30 ° and 60 ° (degrees). This surface is advantageously impregnated by any suitable coating, in particular thanks to a geotextile membrane.
• the inclined enclosure wall 12 is provided, for each compartment, with a ramp 15 extending obliquely with respect to the line of greatest slope.
• the slope of this access ramp at the bottom of the compartment is less than 33% (per cent)
• peripheral track 14 forming a periphery of the compartment, which slopes gently from the free end of a first side wall 3A towards the other side wall 3B.
• This track 14 is extended, at its lower end adjacent to this wall 3B, by a radially inner ramp 15 which opens on the bottom 10.
• the peripheral tracks 14 and 14 'of two adjacent compartments (for example A and F on Figure 2) communicate with each other.
• the enclosure wall 12 is further bordered by a backfill 16, which is raised several meters above the ground level 17.
• a backfill 16 which is raised several meters above the ground level 17.
• Height H1 of space 1 between 4 m and 20 m, typically between 8 m and 15 m.
• the waste treatment plant according to the invention further comprises a cover 20, capable of selectively covering the internal volume of one or the other of the above compartments, depending on the state of progress of the invention. waste treatment process.
• the material constituting this cover which is represented on the compartment 4E (solid and covered) of FIGS. 1 and 2, advantageously has the following characteristics:
• a preferred material is for example a geotextile, the cover then being geo-membrane type.
• the cover can be placed directly on the massive waste, without additional fixation, especially on the side walls.
• fastening means preferably removable attachment, to secure the cover, especially on the aforementioned side walls.
• the capture means equipping the installation according to the invention, can extract, from each compartment, the gases released by the waste during their treatment.
• These sensing means are more particularly visible in FIGS. 5 and 6, as well as in FIG. 3, where the circulation means of the liquid fraction are not represented, for the sake of clarity.
• They comprise, in each compartment, at least one tubular assembly 30, each of which is formed by a main tube 31, extending radially, as well as by secondary tubes 32. These latter extend in the horizontal plane obliquely, on both sides of the aforementioned main tube.
• FIG. 5 illustrates two tubular assemblies 30 and 30 ', regularly distributed over the height of the central space 1.
• the tubes 31 and 32 are advantageously made of a resistant material, in use, at the static pressure of the massive waste. As an indication, such a material is for example polyethylene.
• Each tube, whose cross section is of a diameter included between 5 and 15 cm, is pierced with openings of capture. These openings, provided at regular intervals, typically have a section between 1 and 3 cm 2 .
• the various tubular assemblies placed in the compartments of the installation, open radially inwards into a common manifold 33 provided in the central common space (see in particular FIGS. 5 and 6).
• a common manifold 33 provided in the central common space (see in particular FIGS. 5 and 6).
• the connection between each tube 31 and this manifold is of removable type, for example by means of a movable sleeve.
• This manifold 33 which allows to centralize the gas flows, is associated with a pump 34, for example centrifugal type.
• the latter advantageously has an adjustable power, in order to give a modular character to the depression of the tubular collection network.
• the collector 33 extends out of the central common space 1 and opens into an unrepresented energy production device, for example of the motor (or turbine) type operating with biogas, driving an electric and operating generator. advantageously in a combined cycle.
• the circulation means equipping the installation according to the invention make it possible to recycle the liquid fraction from the bottom of the compartment where this fraction accumulates by gravity towards the top of this compartment.
• These circulation means are more particularly visible in FIGS. 5 and 6, as well as in FIG. 4, where the means for collecting the gaseous fraction are not represented, for the sake of clarity. They comprise, in each compartment, a tubular pump member 43, extending over substantially the entire height of the space 1, which is associated with a circulation pump 44.
• a first end 43 'of the pumping member opens in the vicinity of the bottom of the compartment, through the bottom of the partition wall 1A, while its other end 43 "communicates with a tubular distribution assembly 40.
• the latter is formed by a radially extending main tube 41, as well as secondary tubes 42 extending transversely, on either side of this main tube, advantageously, there is a single tubular distribution assembly 40 placed at the
• the pump member 43 is advantageously equipped with means (not shown) for controlling at least one parameter of the liquid fraction present in each compartment.
• the tubes 41 and 42 are advantageously made of a plastic material.
• a plastic material is for example polyethylene.
• Each tube 41 or 42 whose cross section is for example between 6 and 20 cm 2 , is equipped with injectors, of known type, for dispensing the liquid fraction above the massive waste. These injectors are provided at regular intervals, typically between 1 and 3 m.
• injectors are provided at regular intervals, typically between 1 and 3 m.
• Such a valve or a plurality of such valves makes it possible to empty this circuit and / or to fill it with liquids coming from outside the compartment, especially with a view to to regulate and / or modify the bacterial seeding of recirculated liquids in this compartment.
• Such a valve or a plurality of such valves may also allow communication between the liquids, between the different compartments. It can be provided that a first valve provides the emptying function, while another valve provides the filling function. Alternatively, it can be provided that a single valve provides both emptying functions and filling.
• the common functional space is placed centrally, while the treatment compartments are placed radially at the periphery of this central space.
• the compartments are arranged side by side, for example on two parallel lines.
• the common space, equipped with the functional elements common to these compartments, is then provided medially between the two lines mentioned above.
• compartments are so-called processing compartments, namely that they are separated from the common functional space 1 by one of the peripheral walls 1A to 1F
• at least one compartment is a so-called service compartment, namely that it opens directly into the common functional space 1, without being separated from the latter by a wall, such as than those 1A to
• Such an embodiment is advantageous because it allows particularly simple access to the common functional space.
• the or each service compartment extends in an angular sector, which is smaller than that of the treatment compartments.
• the treatment process carried out in the installation comprises at least the three following stages, namely the filling of each compartment, the anaerobic digestion of the fermentable fraction, and the emptying of each compartment.
• the aforementioned filling is first empty in a hopper, the dumpsters in which are collected waste to be treated.
• the bags containing the waste are disemboweled and then sieved of this waste.
• the waste is ground in order to obtain a predefined particle size, typically of median value of between 20 mm and 80 mm, which makes it possible to improve the efficiency of the anaerobic digestion phase of the treatment. .
• the waste thus ground is then conveyed to the right of each compartment, in particular by unrepresented conveyor belts, then are admitted by gravity into the interior volume of each of these compartments.
• This filling step has a duration typically between 1 and 15 months, especially between 6 and 12 months.
• the compartment is closed.
• the network 40 of circulation surface of the liquid fraction then one sets up the cover 20 above the compartment.
• This closing step has a duration typically between 10 and 30 days.
• the step of anaerobic digestion, or methanogenesis allows in a manner known per se to degrade the organic materials present in the waste, in the absence of oxygen.
• This degradation is ensured by bacteria digesting the cellulosic wall of these organic materials. These bacteria are present in the organic material itself and, where appropriate, may be supplemented by any additional bacteria which are sown in the waste mass.
• the aforementioned degradation essentially leads to the formation of a liquid fraction, mainly comprising water, and a gaseous fraction, or biogas, comprising a substantial part of methane.
• the biogas thus produced is first drawn in by the capture tubes 31 and 32.
• the biogas flow is then combined in the main collector and is then analyzed in real time in order to measure the parameters of the biogas. temperature, flow (in m 3 per second), methane level and oxygen levels, and at regular intervals to determine the presence (or not) of corrosive chemical compounds.
• the biogas is then cooled and dried, and then filtered in order to eliminate, in particular, undesirable chemical compounds, such as chlorinated compounds, sulfur compounds and siloxanes.
• the biogas thus filtered is finally injected into an energy production device, such as a motor (or a turbine) coupled to an electric generator, advantageously operating in a combined cycle.
• the liquid fraction produced during anaerobic digestion is extracted out of the accumulation zone, located at the bottom of the compartment, in the vicinity of the wall bordering the space 1.
• This extraction is carried out by any appropriate means, in particular by a suction pump.
• the flow rate of the pump is measured continuously and the circulating liquid fraction is also analyzed at regular intervals to measure in particular some of the following parameters: bacteria present, pH, ammonium content and various salts.
• the corrective actions may be a bacterial reseeding, a neutralization, a dilution or a reduction of the liquid fraction circulating in each compartment.
• the extracted liquid fraction is then recycled or re-circulated, namely that it is introduced into the massive waste.
• This operation is performed via the tubes 41 and 42, which allow an admission of liquid above the massive waste. This allows in particular to maintain this waste under appropriate conditions of humidity and temperature.
• the volume of this liquid fraction put into circulation is continuously monitored.
• the accumulation zone has a perfectly defined geometry. It is therefore easy to determine the volume of liquid accumulated against the bottom 10, knowing the altitude of the upper surface of this liquid. For example, it is possible to place a high sensor and a low sensor at the bottom of each compartment. This makes it possible to constantly maintain the accumulated liquid volume in a given range, corresponding to the desired humidity level in the compartment.
• the circulation circuit is also associated with a purge, which makes it possible to eliminate a part of this liquid fraction.
• a purge which makes it possible to eliminate a part of this liquid fraction.
• additional liquid is added to the recycled liquid fraction at the level of the tubes 41 and 42.
• pH between 5 and 9, in particular between 6.5 and 7.5.
• this step of anaerobic digestion is implemented, so as to valorize at least 70%, preferably at least 90%, of the degradable organic fraction of the waste.
• This anaerobic digestion stage has a duration typically between 12 and 72 months, especially between 30 and 60 months.
• the compartment is emptied. For this purpose, it first stops the circulation of the liquid fraction, which leads to the drying of the massive waste and the final end of the methanogenesis. Then, remove the upper cover and disassemble the circulation network of the liquid fraction.
• This drying and opening step has a duration typically between 3 and 12 months, especially between 6 and 9 months.
• the emptying of the compartment is carried out, in particular by means of the construction machinery used for the filling operation.
• the various elements of the biogas capture network are also dismantled. Residues discharged, resulting from anaerobic digestion, can then be subject to a thermal valuation, given their high rate of dryness and heat potential. Given the disassembly of the sensing means present in the compartment (which are thus reusable for the next treatment cycle), this emptying step has a duration typically between 1 and 12 months, especially between 3 and 9 months.
• the number of compartments of the installation is determined according to the waste stream to be treated and the intended treatment time.
• the minimum number of compartments of the installation can be calculated by the following formula:
• N T * X / (V * entering), WHERE
• X is the tonnage of waste entering the facility (expressed in tonnes per reference period);
• V is the average volume of the compartments of the installation
• dentrant is the average density of waste entering the facility
• T is the duration of the internal cycle of a compartment, from the beginning of the filling phase until the end of the emptying phase, and including in particular the time necessary to reach the rate of anaerobic digestion targeted by waste treatment (expressed in number of reference periods).
• the number N is rounded to the nearest integer, or any other rounding method relevant to the data taken into account.
• the volume of the compartments is adjusted so that the calculation of N results in a value as close as possible to an integer.
• rounded calculation of the integer N translate a sub-optimization of the use of the installation:
• the compartments In case of rounding down, the compartments must be emptied faster to make room for incoming waste in excess of the total volume available in the facility.
• the duration of the treatment cycle is reduced and therefore the anaerobic digestion rate reached at the end of the treatment is below the theoretical target.
• the treatment of the waste is done in one compartment after the other, while respecting a duration of cycle (of filling to emptying) equivalent for each one, with a shift in the time At (expressed in number of periods of reference) between each compartment, determined by the formula:
• X is the tonnage of waste entering the facility (expressed in tonnes per reference period);
• V is the average volume of the waste reception volume of the compartments of the installation
• dentrant is the average density of waste entering the facility
• T is the duration of the internal cycle of a compartment, from the beginning of the filling phase until the end of the emptying phase, and including in particular the time necessary to reach the rate of anaerobic digestion targeted by waste treatment (expressed in number of reference periods);
• N is the number of compartments constituting the installation.
• the treatment of the waste in the installation according to the invention comprises, for each compartment, an individual cycle starting with the filling phase, followed by the anaerobic digestion phase and then ending with the emptying phase. More generally, the installation according to the invention is controlled according to a sequence composed by the set of individual processing cycles, implemented in the different compartments, which start successively with the time shift At explained above. .
• Example 1 For the treatment of organic waste whose rate of decomposition is high (eg meat, fish, animal fat, etc.) anaerobic digestion can be carried out in 5 months. In this case, a facility receiving 400 tonnes per month of this waste (density 1, 25) in compartments offering a waste reception volume of 1000 m 3 that can be emptied in 1 month, could be configured in 2 compartments.
• organic waste whose rate of decomposition is high eg meat, fish, animal fat, etc.
• the almost complete anaerobic digestion of the fermentable fraction may take about 4 years. .

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