CN111936612A - Reactor and apparatus for anaerobic digestion - Google Patents

Abstract

A continuous stirred reactor (100) for anaerobic digestion of biodegradable organic substrates is provided, the reactor comprising a horizontally extending reactor tank (101) having an inflow port at an entry end and at least one outflow port at a discharge end opposite the entry end. The reactor (100) further comprises means for continuous stirring of the organic substrate inside the reactor tank (101) and a temperature regulation system, advantageously comprising a plurality of internal tubes configured to traverse through the lateral walls and/or the base of the reactor tank and to convey a temperature regulation fluid along the internal tubes.

Description

Reactors and equipment for anaerobic digestion

technical field

The present invention generally relates to systems and methods for anaerobic biodegradation of organic substrates with biogas recovery. In particular, the present invention relates to continuously stirred horizontal reactors for dry anaerobic digestion of organic substrates, and plant facilities comprising said reactor (or reactors).

Background technique

Anaerobic digestion (AD), the complex process of decomposing organic matter by methanogens, has been reduced in use in various biorefinery technologies including agricultural and industrial waste treatment. In all cases, anaerobic digestion is also accompanied by the production of biogas, which is further upgraded to produce biofuels.

Two types of anaerobic digestion processes are generally distinguished in order to manage solid waste with different dry matter (DM) contents, and these two types of anaerobic digestion processes are referred to as "wet" (DM from 5 wt% to 15wt%) and "dry" (30wt% to 55wt% DM). Dry digesters with an average capacity of 950m ³ to 1000m ³ , upgradable to about 2000m ³ are generally more compact than wet digesters with an average capacity of 2m ³ to 4000m ³ . Generally speaking, any anaerobic digester can be used for both wet and dry processes; however, in practice, equipment is designed to meet specific requirements imposed by selection and/or availability of feed materials, expected output, available sites, etc. Require. Other advantages of dry digestion, when used for waste treatment, relate to the tolerance of relatively impure waste, i.e. containing substantial amounts of non-biodegradable material; therefore, the cost of pre-processing and conditioning the feedstock prior to digestion can be minimized .

Conventional AD equipment includes a pretreatment facility, one or more digester reactors, and several post-processing facilities, including a solids separator and sanitary tanks for digested material, and a portion of the digested material as a The inoculum is returned to the recirculation apparatus in the reaction space. Common reactor configurations include stationary dome-shaped tanks with, in most cases, one or more wall-bound mixers. Dry AD reactors operating on a continuous flow-through basis are often referred to as plug flow reactors, and are implemented as a horizontally extending narrow tank with an inlet and an outlet in which the feed is fed. It is continuously decomposed as it travels along the length of the tank. Some plug flow solutions are supplemented with mixers or mixing screws in the form of bladed rods.

Dry anaerobic digestion - also known as dry fermentation - has additional advantages for the following reasons. First, the disposal of the waste portion becomes more challenging. Some waste management measures prohibit landfilling of organic waste; therefore, the portion of waste intended for recycling becomes drier and more difficult to shred due to the presence of large amounts of impurities such as stones, sand and dirt. Incineration of organic waste is a popular solution, but it offers lower energy yields and leads to severe flue gas emissions. On the other hand, while dry matter can be handled to some extent by wet anaerobic digestion methods, wet anaerobic digestion methods do not allow the presence of large amounts of impurities in the feedstock.

However, dry anaerobic digester solutions operating on a continuous flow basis suffer from several common disadvantages. In most cases, biodegradable wastes obtained from agricultural and municipal sources contain substantial amounts of non-digestible solids such as stones, sand, glass and various plastics, which result in slicks and large amounts of plastic in the digester sediment. To handle heavy sediments, US Patent No. 8,241,869 (Büchner et al.) discloses a dry anaerobic fermenter operating on a plug-flow basis, provided in the form of an elongated tubular vessel having Overlapping stirring blades configured to push sediment towards the discharge end and a suction spigot for removing solid sediment from the reactor via an additional outlet. However, this solution does not address the separation of light impurities; therefore a filter station will be required to handle the plastic-rich waste stream.

In addition, the aforementioned indigestible substrates (sand, stones, etc.) cause friction, so the equipment requires a robust feeding system.

An additional challenge involves increasing the capacity of AD equipment without compromising its economic viability in terms of capital investment. Conventional solutions include: increasing the number of reaction tanks per device, which is not always possible due to limited area; and/or providing transmissions that agitate and travel the material through extremely long reactors support. Thus, an exemplary solution according to US patent no. 7659108 (Schmid) relates to detection and compensation of drooping of agitator bars in horizontal anaerobic fermenters, especially in horizontal anaerobic fermenters longer than 50 meters appliance.

In addition, according to existing requirements set out in national and EU standards and regulations for anaerobic digestion processes of biodegradable feedstocks, including Finnish Fertilizer Products Act No. 539/2006 and Finnish Fertilizer Products Act No. 24/11 , and Commission Regulation (EU) No. 142/2011 of Regulation (EC) No. 1069/2009 on animal by-products and derived products not intended for human consumption, that the decomposition products from the AD process must first be purified and then treated with fertilizers. , compost or soil amendments are reintroduced into the ecosystem. In conventional anaerobic digester plants, this purification is carried out in a separate facility, usually downstream of the digester reactor.

Typically, the DM content in the feedstock loaded into the dry AD reactor is significantly higher than that in the wet process. Higher DM content results in lower thermal conductivity; therefore, the dry reactor must have a more powerful heating system. Wet processes have high energy consumption and bring high costs to the recycling process. We point out here that although higher DM content in dry fermentation reactors is not essential, if the reactors intended for dry processing are loaded with feedstocks suitable for processing in (cheap) wet AD plants material, the benefits of dry fermentation will be lost.

The setup of an AD reactor is usually associated with the production of (bio)gas. To maximize the gas production, efficient mixing is required in all types of digestion processes. This remains a challenge for dry AD (fermentation) reactors due to the higher solids content of the feedstock.

In this regard, considering the challenges of applying AD technology as part of a solid waste management system, there is still a need to revise the technology related to anaerobic digestion in horizontal and continuously stirred reactors suitable for biogas production , and in particular, the technology is associated with suboptimal removal of pollutants, blockage of outflow paths, ineffective mixing of materials in the digester, and/or low biogas production.

SUMMARY OF THE INVENTION

It is an object of the present invention to solve or at least alleviate each of the problems caused by limitations and disadvantages of the related art. This object is achieved by various embodiments of reactor arrangements for the anaerobic digestion of biodegradable organic substrates and their associated uses. Accordingly, in one aspect of the present invention, according to what is defined in independent claim 1, there is provided a reactor arrangement for the anaerobic digestion of biodegradable organic substrates.

In a preferred embodiment, the reactor comprises: at least one reactor tank extending horizontally, the tank having an inflow port at the inlet end and at least one outflow port at the discharge end opposite the inlet end; longitudinally extending of at least two stirrers arranged side by side inside the tank; and a temperature regulation system configured to regulate the temperature in the reactor tank and including a plurality of inner tubes configured to longitudinally The direction traverses through the lateral walls and/or base of the tank and transports the temperature regulating fluid along the plurality of internal tubes.

In an embodiment, the reactor arrangement is configured such that the biodegradable organic substrate is transported along the length of the reactor tank towards the discharge end such that: the digested organic substrate is discharged from the tank through the main outlet port and is indigestible The residue is discharged through at least one auxiliary outflow port.

In an embodiment, the lateral walls defining the interior of the can in the longitudinal direction are inclined such that one or more inclined elements are formed along the entire length of the can at the intersection between the lateral walls and the bottom. In an embodiment, each of said lateral walls comprises one or more panels that are substantially flat, said one or more panels having inclined elements arranged as separate modules.

In some embodiments, each agitator includes a drive rod having several blades mounted to the drive rod. In an embodiment, an inner tube is arranged inside the drive rod of the agitator, the inner tube being configured to transport the temperature regulating fluid along the inner tube.

In some embodiments, the temperature conditions in the tubes arranged in the lateral walls of the tank and the temperature conditions in the tubes arranged in the base of the tank are independently adjustable.

In an embodiment, the reactor arrangement further comprises a pretreatment facility having at least one feed supply device configured to regulate the temperature of the organic substrate entering the at least one reactor tank to be consistent with that maintained in the tank temperature matches.

In some embodiments, the reactor also includes a sanitation system for thermal purification of the digested substrate. In an embodiment, the sanitation system is provided in an aftertreatment facility arranged downstream of the at least one tank.

In an alternative embodiment, the sanitary system includes at least one enveloped conduit configured to traverse through the lateral wall and/or base of the tank in a longitudinal direction and to receive digested substrate discharged through the main outlet port.

In an embodiment, the reactor arrangement further comprises a heat recovery and circulation system configured to recover heat generated in the at least one tank during the anaerobic digestion and direct the recovered heat to the pretreatment facility.

In some embodiments, the heat recovery and circulation system is further configured to direct the recovered heat to a temperature regulation system and optionally to a sanitary system.

In an embodiment, the heat recovery and circulation system includes at least one heat exchanger unit for mediating heat transfer between the at least one tank and the pretreatment facility.

In some embodiments, the reactor arrangement includes several tanks arranged next to each other.

In another aspect, according to what is defined in independent claim 16, there is provided the use of a reactor arrangement for the anaerobic digestion of organic waste.

In a further aspect, according to what is defined in independent claim 17, there is provided the use of a reactor arrangement for biogas production.

The utility of the invention arises from various reasons in accordance with each embodiment of the invention. First, the present invention provides a compact reactor solution, the length of which is reduced by at least two times compared to conventional AD reactors of the same type, wherein this is compensated by the provision of at least two reactor sub-zones arranged side by side reduced length. The absence of dividing walls between the agitator units allows for efficient mixing of the digested matrix. By reducing the length of the reactor, excessive loads on the agitator and/or drive motor are avoided, thereby increasing the stability and reliability of the reactor, improving mixing efficiency, reducing energy requirements, and allowing Save a lot of repair and maintenance costs.

In addition, the system provided within the reactor for efficient sorting and recovery of effluent/residues allows the processing of "dirty" feedstocks including deposits and/or light impurities such as plastic packaging and The wrappings are heavily contaminated with organic substrates. An efficient sediment recovery system further prevents the formation of a solid layer on the bottom of the reaction tank and creates the prerequisites for continuous flow dynamics therein.

Due to its pre-fabricated construction mode, the disclosed reactor solution can be easily and quickly assembled on site. Additionally, with regard to pre-fabricated building blocks, the pre-fabricated building blocks for the reactor are designed to be suitable for transport by conventional motor vehicles or platforms, including on standard bridges (eg highway bridges) under transport and via road tunnels; therefore, no special transport is required.

The reactor solutions disclosed herein also allow for preheating of the feedstock such that when the matrix material enters the reaction space, the temperature of the matrix material is close to that required for microbial activity.

Furthermore, the reactor employs an integrated heat recovery and circulation (recycle) concept, so that the heat obtained during AD processing in the reaction tank is recovered for various facilities upstream and downstream towards the reaction space. Further storage and/or recycling. In addition, the heat thus recovered can be further used to adjust the temperature within the reactor tank to obtain conditions most favorable to the bacterial population present in the tank. As a result, the present reactor is fully capable of cost-effective operation under thermophilic conditions (42°C to 97°C, preferably 42°C to 66°C, and in some cases 43°C to 55°C) during winter in the Nordic climate. operate in a cost-effective manner.

The provision of a sanitation system integrated inside the walls and/or base of the reactor tank increases the compactness of the overall solution and naturally eliminates the need to build a separate purification facility. Similarly, an integrated system of hollow tubes for circulating temperature-regulating fluid inside the walls and/or base of the reactor tank further allows fine-tuning of the reaction conditions within the system for the Biodegradation creates the most favorable environment. By adjusting the temperature inside the reactor, the population of mesophilic and thermophilic bacteria can be adjusted, thereby changing the biogas production accordingly.

Overall, the reactors disclosed herein meet the requirements necessary for efficient digestion of (organic) waste fractions under anaerobic conditions in a cost-effective manner, ie: in the entire reactor facility (including feeders) constant temperature conditions are maintained in the reactor; uniform and efficient mixing is performed over the entire length of the reactor tank; and feedstock materials are uniformly supplied.

The expression "organic substrate" in the present disclosure refers to a substrate material of biological origin; whereas the term "biodegradable" refers to an (organic) substrate that decomposes naturally and/or as a result of the biological activity of microorganisms. The term "anaerobic" in this disclosure refers to a biodegradation process that takes place in the absence of oxygen.

The expression "number" is used in the context of this document to refer to any positive integer starting from one (1). The expression "plurality" here refers to any positive integer starting from two (2), eg to two, three or four.

Various embodiments of the present invention will become apparent upon consideration of the detailed description and drawings.

Description of drawings

1A, 1C and 1D schematically illustrate a reactor arrangement 100 for anaerobic digestion according to an embodiment. FIG. 1B is a perspective view of the reactor arrangement 100 according to an embodiment. Figure 1E shows a top assembly for a reactor arrangement 100 according to an embodiment.

2A, 2B, and 3 illustrate exemplary configurations of reactor arrangements 100. FIG.

4A-4D schematically illustrate cross-sectional views of reactor tank 101 for various configurations of reactor 100 .

5A is a longitudinal cross-sectional view of reactor arrangement 100 in an exemplary configuration. 5B is a plan view of the anaerobic digestion arrangement 100 viewed from the top, according to an embodiment.

Figure 6 shows the reactor tank 101 viewed from the side, according to an embodiment.

FIG. 7 schematically shows the heating and temperature regulation system within the reactor arrangement 100 .

Detailed ways

Detailed embodiments of the present invention are disclosed herein with reference to the accompanying drawings. The same reference numerals are used to refer to the same components throughout the drawings. The following references are used for the following components:

100-reactor arrangement for anaerobic digestion,

101 - Reactor Tank,

201 - Aftertreatment facility optionally with mechanical parts,

202 - Sediment discharge device,

203 - Discharge device for digested matrix,

301 - feed tank with (optional) cover 311,

302 - first feed supply device,

401 - Pretreatment Facility,

402 - Second Feed Supply Device (Temperature Adjustable),

501A - for the top of a reactor support structure (reactor support structures),

10, 10A, 10B - the inside of the reactor tank,

11, 11A, 11B - Lateral (Wall) Profiles,

12, 12A - base element and extension of the corresponding base element,

13 - External Insulation/Gasket,

14 - External base element,

15, 501 - Cover and top respectively above the reaction tank,

16, 17 - entry end and corresponding discharge end,

18 - Incoming port,

19, 20, 21 - outgoing ports,

22 - agitator

23 - Transmission rod/shaft,

24, 24A, 24B - mixing blades and parts of mixing blades,

25 - Separation device,

26 - The recess for housing the drive rod,

27 - Drive rod support element,

30 - Health System,

31, 32, 33 - Flow conduits, sheaths and extraction apertures for sanitary systems according to embodiments,

40-Temperature adjustment system,

41, 42 - the walls of the reactor tank and the tube(s) inside the base,

43 - Tube(s) inside the drive rod,

44 - Heat Recovery and Circulation Systems,

50 - Heat Exchanger Unit,

51 - Central heat distribution and control unit,

1A-1C schematically illustrate at 100 below the concept of various embodiments of an anaerobic digestion reactor arrangement - hereinafter reactor - 100 in accordance with aspects of the present invention. The arrangement 100 advantageously includes at least one reactor tank or pool 101 , a pre-treatment facility 401 and a post-treatment facility 201 . The pretreatment facility advantageously includes various feeders 302, 402, several storage vessels 301 for storing feedstock materials, chemicals, buffers, etc., and various mechanical solutions. The aftertreatment facility 201 advantageously includes an exhaust apparatus 202, heat recovery and heat purification solutions, and optional mechanical solutions.

FIG. 1B shows an exemplary arrangement 100 configured as an anaerobic (biological) digestion plant comprising two reactor tanks 101 (see top 501 ) having a common pretreatment facility 401 and a belt A common aftertreatment facility 201 with a discharge facility. The various devices (eg 301 , 302 , 402 ) configured for pre-treating and feeding the raw material into the tank(s) 101 may be located in a separate "processing" hall (Fig. IB, left side building, Fig. 5B) and/or in a pretreatment section arranged upstream of the tank(s). Elements denoted by reference numerals 301, 302, 401 and optionally 402 are device-specific (depending on the size of the device, substrate, climatic conditions, etc.) and may vary from implementation to implementation. Preferably, the feed supply device 402 configured for thermal treatment of organic feedstocks is provided substantially unchanged in each of the embodiments described herein and/or understood by those of skill based on the present disclosure.

The reactor arrangement 100 advantageously includes: a temperature regulation system configured to regulate the temperature in the reactor tank (or tanks); and a heat recovery and circulation system configured to allow The heat generated in the tank(s) during the anaerobic digestion is recovered and the heat thus recovered is directed to the pretreatment facility 401 and optionally to a temperature regulation system. The mentioned system will be described in further detail below.

Thus, the reactor arrangement 100 includes a horizontally elongated tank 101 which constitutes a reaction chamber (reaction space). Accordingly, in some preferred embodiments, the reactor tank 101 has the following dimensions as expressed in length x width x height: 21m x 12m x 6m to 7m.

The reactor tank 101 is defined by a horizontally extending quadrilateral vessel having an inlet end 16 for receiving organic feedstock and a discharge end 17 for extracting digested slurry (digestate). For purposes of clarity, in this disclosure, the terms "digestate" and "digested substrate" refer to any substantially solid by-product of anaerobic digestion other than biogas. Feedstock supplied from feed tank (or feed tanks) 301 in pretreatment facility 401 is received into reactor tank 101 through feed inlet port 18 (inflow port) provided at inlet end 16 .

In a preferred embodiment, the reactor tank 101 is rectangular at the bottom of the reactor tank 101 . In this case, the width of the tank is the same at the inlet end and the discharge end.

In some other embodiments, the reactor tank 101 may be configured as a quadrilateral body that is wider at the discharge end 17 than at the inlet end 16 (not shown). At the base of the quadrilateral body, this configuration forms an upside-down isosceles trapezoid (with the narrower base of the isosceles trapezoid at the entry end 16).

The reactor tank 101 houses within the interior 10 of the reactor tank 101 at least two agitators or mixers 22 positioned side-by-side and extending in the longitudinal direction through the entire length of the reactor tank, which is described herein. Defined in the disclosure as the distance from the entry end 16 to the discharge end 17 .

As mentioned above, the agitator shaft should not be too long. On the other hand, the AD reactor tank must have a capacity of at least 800 m ³ ; otherwise the stability of the reactor state is compromised. Both requirements are met by providing a tank with dual mixing shafts (ie two shafts positioned next to each other).

The agitators may be arranged strictly parallel (in the case of the "rectangular" tank 101 ), or the agitators are preferably not more than 45 degrees off the longitudinal axis of symmetry in each direction (in the case of the "trapezoidal" reactor tank 101 ) ).

Each agitator 22 includes a drive rod 23 configured as a shaft with several mixing blades 24 . The shaft is advantageously provided as a tubular body having a wall thickness in the range from 30mm to 70mm, preferably in the range from 50mm to 70mm, also preferably in the range from about 60mm to 65mm. In some embodiments, the mixing blades 24 are configured to fit to the blade paddles (vanes) of the drive rods, respectively, to follow a generally radial pattern ( FIGS. 2A , 2B ) or a generally helical pattern (not shown). In some alternative embodiments (not shown), each mixing blade may be configured as an open impeller comprising a series of vanes attached to a central hub fitted to the drive rod 23 . The agitator may also be constructed as a helical ribbon impeller (not shown).

FIG. 1C shows an exemplary configuration of a reactor including mixing blades 24 configured as paddles made from separate components 24A, 24B. The innermost part 24A (dashed frame) of each blade is provided as a pair of tubular elements which can run through the shaft 23 and be fixed, for example by welding, whereby the amount of mechanical stress to the blade is minimized, And the entire shaft structure is given torsional stiffness. The innermost component 24A may be fastened to the shaft(s) 23 already located at the manufacturing facility. Attachment of the outermost component 24B to the innermost component 24A may be accomplished, for example, via a joint coupling followed by welding.

To facilitate transport of the shaft(s) about 20 m long, the outermost part 24B may be fastened to the innermost part 24A at the location where the reactor arrangement 100 is assembled. As can be seen in Figure 1C, other identical mixing vanes 24 are mounted on the shaft(s) 23 such that each subsequent vane is rotated 45 degrees relative to the previous vane. These positions are fixed. For example, the outermost ends of the mixing blades 24 denoted by Roman numerals (ii) and (iv) on Figure 1C point in four cardinal directions, namely, North (N)-South (S) and East (E, respectively) )-west (W); while the leaves indicated by numbers (i) and (iii) point in four intermediate directions, namely, southwest-northeast and northwest-southeast, respectively. In the above example, compass directions are used.

Where the reactor tank 101 follows a trapezoidal shape, the diameter of the series of vanes 24 is preferably configured to gradually increase towards the discharge end 17 .

Rod 23 is preferably engine driven. At least one motor motor, preferably an electric motor (not shown), may be provided within the machinery section provided in the aftertreatment facility 201 and/or the pretreatment facility 401 . In some cases, at least one additional drive mechanism may be mounted on the exterior of the tank 101 adjacent the incoming "front" end 16 of the tank 101 to interface with the drive on the "rear" of the reactor disposed within the mechanical section Main motor engine pairing. By providing at least two motors at both ends of the reactor tank, overloading of the stirrer can be avoided. The mechanical portion may also include additional mechanisms, such as various controllers, amplifiers, and the like.

It is also preferred that the gearbox and motor head are arranged in an area within the pretreatment facility 401 . With this arrangement, the sealing structure for the stirrer can be replaced even when the reaction tank(s) are filled with the matrix material.

In order to provide the most efficient agitation of the reaction substrate within the reactor tank 101, the agitator 22 is set to rotate in opposite directions (as indicated by the arrows on Figures 2A, 2B); The center is directed towards the sides of the tank and then returned to the center. A preferred rotation pattern is also shown in Figure 4A (direction drawn by arrows), where the agitator on the right side of the reactor tank 101 (as viewed from the entry end 16) is set to rotate clockwise and, correspondingly, the agitator on the left side set to rotate counterclockwise. In other configurations, the agitators 22 may be set to rotate toward each other (right-counterclockwise; left-clockwise); or alternatively, the agitators 22 may be set to rotate in the same direction.

The arrangement of the vanes 24 in a radial and helical/helical pattern on the drive rod 23 is preferably such that the spacing between the individual vanes 24 at the entry end 16 is greater than the spacing at the discharge end 17 . The increase in blade density per unit distance along the drive rod 23 allows for efficient processing, ie mixing of the reactive matrix, which in turn increases in density along the length of the tank 101 from the inlet end 16 towards the discharge end 17 decreases as it travels because the organic substrate is dissolved in the reactor due to anaerobic digestion.

Reactor 100 is preferably configured as a horizontal plug flow reactor (PFR) for continuously stirred anaerobic digestion processing of organic substrates. In the present disclosure, the term "anaerobic digestion" refers to a process by which microorganisms degrade organic matter under anoxic conditions over a wide temperature range with concomitant production of biogas. Based on the temperature range, two sub-processes can generally be identified: mesophilic digestion in the range from 10°C to 48°C, preferably in the range from 30°C to 42°C, and in the range from 42°C to 97°C , preferably thermophilic digestion in the range of 42°C to 66°C, and in some cases in the range of 43°C to 55°C. Thus, microorganisms that are stable and active within the ranges indicated above refer to mesophilic and thermophilic microorganisms.

In fact, according to Brock Biology of Microorganisms (12th ed., Madigan, Martinko, Dunlap, and Clark), thermophilic microorganisms are subdivided into: Thermophilic bacteria such as Geobacillus stearothermophilus active at 60°C; hyperthermophiles 1 active at temperatures ranging from 67°C to 97°C, optimally at 88°C ), such as Thermococcus celer (Thercococcus celer); and hyperthermophilic bacteria 2, such as Pyrolobus fumarii, which are active at temperatures above 100°C. For the purposes of the present invention, the thermophilic temperature range is defined as 42°C to 97°C.

An exemplary representative of mesophilic microorganisms is E. coli with an optimum temperature of about 39°C.

Mesophilic microorganisms demonstrated increased efficiency and yield in biogas production; however, thermophilic microorganisms were also more sensitive to changes in temperature, pH levels, redox potential, and to the presence of inhibitors such as heavy metals, antibiotics, and detergents. The reactors 100 provided herein can be configured to operate with mesophilic microorganisms, thermophilic microorganisms, or with both types of microorganisms present in the reactor tank insofar as the above parameters are adjusted to appropriate values. As the organic matrix material travels through the reactor 100, the organic matrix material gradually dissolves due to the activity of the microorganisms.

Thus, during bacterial-mediated anaerobic digestion, the biodegradable organic substrate is decomposed to produce biogas and a roughly solid residue, commonly referred to as digestate. The digestate includes fibrous material (cellulose and lignin), dead bacterial cells, and a sludge-like fraction containing solids and methanogenic liquids. These by-products can be further used as fertilizers, compost, low-grade building materials such as fiberboard, and/or as feedstocks for ethanol production.

Feed input for reactor 100 is primarily represented by organic waste of vegetable or animal origin, such as field (vegetable) biomass and by-products (bagasse, bran, straw), kitchen and catering (bio) Waste, household and/or municipal waste, by-products of the food industry, forestry, agriculture (farming, animal and poultry raising), and sewage slurries and waste cement slag.

Obviously, the above-mentioned raw materials vary widely in terms of purity. In this regard, field biomass and crop by-products, for example, are substantially free of indigestible or non-digestible impurities, or field biomass and crop by-products contain negligible amounts of indigestible or non-digestible impurities in the form of gravel or sand quantity. On the other hand, household or agricultural bio-waste usually contains a large amount of pollutants represented by indigestible plastics and/or metals and various indigestible organic by-products such as wood and/or wood processing for example of industrial by-products.

In order to efficiently treat these indigestible fractions present in the reaction matrix traveling through the reactor tank 101 , in particular the indigestible portions traveling through the reactor tank 101 from the inlet end 16 along the length of the reactor tank towards the discharge end 17 Reacting these indigestible parts of the matrix, the reactor arrangement 100 also includes means for sorting and separating the digested matrix from the indigestible residues and extracting the digested-containing materials from tanks 101 independent of each other part and part containing residues.

With further reference to Figure 3, Figure 3 shows the reactor tank 101 within the reactor arrangement 100 (after-treatment facility 201 not shown). Thus, the reactor tank 101 includes a feedstock receiving inflow port 18 at the inlet end 16 and at least one outlet port at the discharge end 17 opposite the inlet end 16 . In some configurations, the reactor includes several outflow ports 19 , 20 , 21 at the discharge end 17 . The biodegradable organic matrix comprising feedstock (F) supplied from a feed tank (not shown) via the pretreatment facility 401 enters the reactor tank 101 through the inflow port 18 . As mentioned above, feedstock (F) includes various solid, indigestible contaminants suspended in the feedstock.

With the feedstock (F) traveling along the length of the reactor tank 101 while being continuously agitated by at least two agitators 22, the biodegradable organic matrix material contained in the feedstock is assisted by mesophilic microorganisms and/or Thermomicroorganisms undergo a process of anaerobic digestion. At the same time, heavy, non-buoyant, indigestible sediments such as stones, gravels, sand, glass, metal particles, etc. are dragged downward due to their own weight and sink to the bottom of the tank 101, while light, Buoyant, indigestible residues such as plastics, for example, float on the surface of the organic matrix material and reside there. In conventional digesters with inlets and outlets, this indigestible contaminant must be removed manually when emptying the reactor(s) to avoid clogging the discharge path and/or to avoid being at the bottom of the reactor tank A layer of sediment is formed on it. The formation of a sediment layer causes a rise in the base level, which alters the flow dynamics that arise during agitation.

The reactor arrangement 100 may be configured to allow for continuous and efficient removal of indigestible contaminants from the reaction space 101 during the digestion process. Thus, the digested substrate (digestate), denoted by the capital letter D on FIG. 3, can be discharged from the reactor tank 101 via the main outlet port 19, while the non-buoyant indigestible residue R1 (sediment) can be discharged via the first An auxiliary outflow port 20 discharges. The digested matrix D thus obtained is free of solid, indigestible material, or contains insignificant or negligible amounts of indigestible impurities. In any event, the digested matrix D did not require further purification and/or refining.

The reactor 100 may also include a second auxiliary outflow port 21 configured to receive light, buoyant, indigestible residues R2 (floating matter), such as various non-recyclable plastics (plastics). packaging, Styrofoam, etc.). Accordingly, in some cases, the auxiliary outflow ports 20 and 21 may be arranged directly below or above the main outflow port (see Fig. 3, port 21). Alternatively, either of the auxiliary ports 20 , 21 (see FIG. 3 , port 20 ) may be displaced laterally in a horizontal plane relative to the position of the main port 19 . In some other cases, the at least one auxiliary outflow port 20 , 21 may be arranged at the same level as the main outflow port 19 .

The reactor arrangement 100 may also include a number of devices configured to: suspend the suspension during anaerobic digestion as the organic matrix material travels along the length of the reactor tank 101 towards the outflow ports 19 , 20 and/or 21 . mediated separation and classification of solid, indigestible substances in organic matrix materials.

In the next configuration, the reactor arrangement 100 includes a sediment discharge device 202 ( FIGS. 1A , 2A, 2B ) configured to remove the non-buoyant indigestible residue R1 from the tank 101 . The bottom is delivered to the outside of the reaction space via the first auxiliary outflow port 20 . A device 202 is arranged at the discharge end 17, optionally within the aftertreatment facility 201, and configured as at least one conveyor, such as designed to collect accumulation on the bottom of the tank 101 and towards The discharge end 17 travels slowly (due to agitator mediated agitation) to a screw conveyor of solid deposits such as gravel and sand. Thus, in the embodiment shown in Figures 2A and 2B, 101, means 202 comprise: a conveying screw provided within the tank 101 and arranged in a substantially horizontal plane; and a second conveying screw 202, the first Two conveying screws 202 are arranged in the riser to convey the deposited residue R1 upwards before it is withdrawn from the reactor 100 . After removal from the reactor 100, the solid, non-buoyant sediment is collected for recovery. Alternative configurations include a single elevated or non-elevated conveyor, such as, for example, a screw conveyor. Regardless, any other suitable form of implementation may be utilized. Also shown on Figure 5A is a device 202 disposed within the reactor arrangement 100.

In some configurations, the reactor 100 also includes an additional residue discharge device (not shown) configured to be present on the surface of the organic matrix material traveling along the length of the reactor tank 101 . The buoyant indigestible residue R2 on the surface is transported to the outside of the reaction space via the second auxiliary outflow port 21 . A possible configuration of the additional residue discharge means includes a conveyor configured to convey the lightweight plastic residue R2 in a horizontal plane and/or down for further collection and recycling.

FIG. 2B shows an exemplary configuration in which the reactor 100 further includes a number of separation devices 25 located within the reactor tank 101 for promoting difficult suspension in an organic matrix. Separation of digested (both buoyant/floating and non-buoyant/sedimented) matter. The separation device 25 may be constructed with a vertical bar fixed to the lower end of the bottom of the tank 101, the bar being set to perform a vibrating or oscillating movement. The rod is preferably motor driven. Separation device 25 is preferably positioned adjacent discharge end 17 of tank 101 to facilitate separation of digested (biodegradable) organic products from indigestible solids, and correspondingly digested product D and residue R1 and/or R2 is sorted towards the appropriate outflow ports 19 , 20 and/or 21 .

In some configurations, the reactor tank 101 includes several optionally identical outflow ports 19, 20, 21 for discharging (unseparated) digestate D. In this case, the separation of indigestible residues occurs elsewhere. All outflow ports can be located at the same level or at different levels. It should be noted that more than three outflow ports may be provided per tank.

Referring further to FIGS. 4A-4D , FIGS. 4A-4D illustrate various embodiments of the reactor arrangement 100 in cross-section of the reactor tank 101 . In this regard, the tank 101 is defined by lateral walls (side walls) in the longitudinal direction. In order to achieve a more efficient mixing of the reaction substrates in the reactor tank 101 and to avoid deposits from accumulating in the corners formed at the intersection between the (lateral) wall profile and the bottom, the reactor tank 101 is defined in the longitudinal direction Each lateral wall of the interior 10 is sloped (oblique). Thus, the inclined elements denoted by the capital letter S are advantageously formed along the entire length of the reactor tank 101 at the corners or intersections where the lateral walls meet the bottom.

FIG. 4A shows an exemplary configuration in which each lateral wall is defined by several L-shaped profiles 11 ; whereby an inclined element S is correspondingly incorporated into each L-shaped profile . The tilting element S is shown by dashed lines on Figure 4A.

In the configuration of FIG. 4A , the L-shaped profiles 11 forming the lateral walls are advantageously positioned opposite each other and joined at the bottom by one or more base (central) elements 12 , such that inside the reactor tank 101 10 At least two adjoining subsections 10A, 10B are formed therein, wherein each subsection 10A, 10B is configured to receive an agitator 22 (not shown; the direction of rotation is depicted by the arrow). Thus, the base element(s) 12 are arranged to form a raised separation between the subsections 10A, 10B. The height of the divider can optionally be increased by mounting extension element(s) 12A on the divider. In some configurations (not shown), the central base element(s) 12 (shown in FIG. 4A ) may be provided as a generally flat panel(s) with optional mounting to separate divider element for the panel.

The individual L-shaped profiles 11 are positioned opposite each other in pairs in order to comply with the principle of mirror symmetry. The L-shaped profile 11 is configured such that the reactor tank 101 is externally defined as a tank that is rectangular at the base of the tank, while the inner surface of the tank 101 is curved to allow at least two adjoining subsections 10A, 10B Correspondingly, at least two stirrers 22 are accommodated therein.

Figures 4B-4D show preferred configurations of the reactor arrangement 100.

Thus, Figure 4B shows a configuration in which each lateral wall is formed by a generally flat vertical panel 11A. For each lateral wall 11A, the inclined element (S) may be provided as a separate module 11B.

In some configurations, the side panels forming the side walls are provided approximately 450 mm thick, while the panels forming the head end (front and rear) walls 16 and 17 are correspondingly approximately 550 mm thick. The mentioned panels are preferably produced by casting or moulding, such as for example continuous moulding. As shown in FIG. 4C , a plurality of (here, two) holes or recesses 26 are formed in each of the end panels 16 , 17 to receive the shaft 23 . Additional support for the shaft is further provided by providing support/reinforcing legs 27 at each end 16, 17 of the tank 101 (Figs. 1C, 6). The legs 27 may be provided as concrete slabs about 600mm thick.

In a preferred embodiment, the arrangement 100 includes at least two reactor tanks 101 placed next to each other (FIG. 4D). In this case, two adjacent reactor tanks advantageously share a lateral wall 11, which can be provided as a dividing wall between the two reactor tanks (see Figs. 4D, 5B). Nonetheless, providing more than four reactor tanks arranged side-by-side does not necessarily appear to be feasible due to thermal expansion. Where more than four tanks are positioned side by side, a moving seal is required.

The sloped surface can be curved (FIG. 4A) or flat (FIG. 4B). The inclination (oblique) angle (theta, θ) may vary from about 35 degrees to about 60 degrees; preferably, the inclination angle may be set to about 45 degrees. Figures 4C and 4D show a reactor configuration comprising a separate inclined element 11B with a slightly curved inclined surface.

In the configuration shown in FIGS. 4B to 4D , the base element 12 is provided as a generally flat panel (eg 600 mm thick); thus, at least two stirrers 22 are received in the undivided interior 10 . In a further configuration (not shown), the arrangement of the base element may be accomplished in the manner shown in Figure 4A. Accordingly, the reactor tank as shown in Figure 4B may also include separate dividing elements (not shown) to separate the interior 10 into at least two subsections. Each tilting module 11B is in turn provided as an elongated block or several continuous blocks extending through the entire length of the tank 101 .

To ensure efficient mixing of the materials within the reactor tank 101, the reactor tank 101 is configured to have a generally flat bottom, as shown in Figures 4B-4D.

Reactor 100 also advantageously includes at least one layer of outer liner and/or insulation 13 (FIGS. 4A, 4B). The reactor tank 101 is also placed on the base element 14 and sealed from the top by a flexible or rigid cover 15 (Figs. 1C, 1D, 4C, 4D).

Although biogas is the end product of bacterial digestion of organic feedstock entering the reaction space, most biogas is produced during the digestion process, therefore, reactor 100 is advantageously equipped with an inflatable cover and/or top for storing biogas . The flexible cover 15 is provided as an inflatable layer or layers which, when inflated, can be accommodated in a fixed, rigid dome-like top structure 501 (FIGS. 1A-1E). In some cases, the cover 15 may be constructed as a rigid fixed structure (dome-like or flat), in which case the reactor is advantageously equipped with a biogas extraction system (not shown).

It is generally preferred that the top structure for reactor arrangement 100 is configured as a dual membrane structure comprising inner membrane layer 15 and outer membrane layer 501 . The outer layer 501 is typically aerated with air and is configured to maintain the shape of the outer layer even in the absence of biogas production activity in the reactor tank(s) 101 . The outer membrane 501 may be configured to cover several reactor tanks 101 at a time (each reactor tank is covered with an inner membrane 15), for example: one reactor tank at a time (FIG. 1B, FIG. 1C) or several reactor tanks (FIG. 1C) at a time. Figure 1D, Figure 1E). The inner membrane 15 is usually formed by an inflatable gas-tight membrane when the biogas is generated inside the reactor tank. Double membranes can be removed from one or more tanks for repair and maintenance. The above actions require removal of both membranes for safety reasons (recovering an air/oxygen rich atmosphere in a typical anaerobic tank). When maintenance work is performed in a single tank, the other tanks in the reactor arrangement can still function normally (although in some configurations the outer membrane 501 has been removed).

In some configurations, the top 501A of the building or other support structure incorporating or housing the anaerobic digestion reactor tank(s) is positioned at an angle (FIGS. 1B, 1C). In the example shown in Figures IB and 1C, the walls of the pretreatment side 401 (feed side) are about 9 m high, while the walls of the post treatment side 201 (output side) are about 6 m high. In the described configuration, each reactor tank 101 is covered by a double membrane (layers 15 and 501). The reactor facility shown in Figures 1B, 1C is particularly suitable for geographic locations with large body temperature and climate, which eliminates the risk of snow and rain accumulation between the tops.

Figures 1D and 1E show a reactor arrangement in which the reactor tanks 101-1, 101-2 are covered by a common top (outer membrane 501). This configuration is achieved without a sloping top structure. The reactor arrangement shown in Figures 1D, 1E is particularly preferred in Nordic climates as it allows to avoid accumulation of snow and rain on the top 501 (from which the snow flows down).

The lateral profiles 11, 11A and/or 11B and the base (central) element 12 can be realized as precast blocks preferably made of concrete (formed and hardened before transport to the construction site). Typical concrete blocks or slabs include powdered Portland cement, water, sand and gravel. In some cases, the heavy sand and gravel in the concrete block can be replaced, for example, with lightweight expanded clay or expanded clay aggregate. In some cases, precast cinder blocks may be used in which the aforementioned gravel and sand are replaced by coal and/or cinder.

The wall structure and base structure are preferably made of concrete and moulded in situ (at the site where the reactor is assembled).

Additionally or alternatively, the aforementioned profile may be made of metal. Metal-based configurations include solutions consisting of sheet metal and an optional core. In some embodiments, the lateral walls 11, 11A are concrete slabs and the inclined modules 11B are metal-based blocks. Complete metal-based configurations are not excluded.

In some embodiments (not shown), the reactor tank 101 may comprise several base (central) elements 12 positioned side by side to form at least two partitions extending parallel in the longitudinal direction so as to be within the interior 10 of the tank 101 At least three contiguous subsections are formed. This configuration allows to accommodate at least three stirrers 22 arranged in parallel within the interior of the reaction space 10 .

Preferably, the reactor arrangement 100 also includes a sanitation system 30 for thermal purification of the digested substrate (Figs. 3, 4A, 4B, 5B). The sanitization system 30 is configured for post-treatment of the digested substrate D via inhibition and/or inactivation (thus, reversible or irreversible loss of microbial activity) of microorganisms contained in the digested substrate; thereby eliminating or At least epidemiological risk is reduced.

Thus, the sanitation system 30 is configured to transfer heat as a stream of thermal energy to the digested substrate; thus, the attenuation/elimination of microbial activity is thermally induced. For example, sanitization was performed at a temperature of 70°C for 1 hour; and sanitization was performed at a temperature of 100°C for 20 minutes; therefore, the flow rates through the devices forming the sanitation system have been adjusted accordingly adjust.

In a preferred configuration, the sanitation system 30 is provided in the aftertreatment facility 201 arranged downstream of the at least one tank 101 . The sanitation system 30 may be combined with a discharge device 203 configured to collect the digested substrate D from several tanks 101 and deliver the digested substrate to the outside of the reactor arrangement 100 (Fig. 5B) . In some configurations, the device 203 may be constructed as a conveyor, such as, for example, a scraper conveyor, and the sanitary system 30 may be constructed around the conveyor to establish a heating jacket. Alternatively, the discharge device 203 may be configured as a heated conveyor or conduit for conveying the digested substrate from the number of tanks 101 towards the outlet.

Whether or not the digested substrate needs to be post-treated, ie sanitized, the device(s) 203 configured as eg a piping system can be used for heat recovery via eg several heat exchanger units 50 (FIG. 5B).

In some alternative configurations, the sanitation system 30 may be incorporated into a sloping element S formed inside the reactor tank 101 (FIGS. 3, 4A, 4B). In this case, the sanitary system comprises at least one conduit 31 enclosed in a sheath or sheath 32 . Heat is transferred to the conduit(s) 31 via the jacket(s) 32 . One or more conduits 31 are configured to traverse through the lateral walls and/or base of the tank 101 in the longitudinal direction and receive digested substrate discharged through the main outlet port 19 .

The conduit(s) 31 may be configured to traverse each lateral wall through the reactor tank 101 defined by several L-shaped profiles 11 (FIG. 4A). Regardless of whether the L-shaped profile is formed from concrete slabs, in order to accommodate the sanitary system 30 in the L-shaped profile, each said slab includes a prefabricated through-hole that forms a hollow when the reactor tank is assembled A tubular tube or channel. Alternatively, conduit(s) 31 may be configured to traverse through tilt module 11B (FIG. 4B). Additionally or alternatively, the conduit(s) 31 may be incorporated into the base (central) element(s) 12 .

Sanitation system 30 implemented as shown in Figures 3, 4A, 4B is configured to receive digested substrate D discharged from reactor tank 101 through main outlet port 19 to mediate said substrate D from the discharge end Section 17 travels along at least one conduit 31 to the entry end 16, whereby microorganisms present in the digested substrate are inhibited and/or inactivated and passed through the arrangement at the entry end of the reactor tank 101 of at least one opening 33 to extract the post-treated (hygienic) substrate D1. The post-processed digested substrate D1 withdrawn from the inlet end 16 of the reactor 100 is further transported elsewhere for storage or transport.

Figures 3, 4A, 4B show a sanitary system 30 in the form of a single U- or Y-shaped conduit passing through the main outlet port 19 (at the discharge end 17) The two lateral walls, in particular the inclined elements S passing through the lateral walls, face the opening 33 arranged at the entry end 16 . Alternatively, the conduits extending through each lateral wall 11 may be provided as separate elements. Thus, the digested substrate D is purified by thermal post-treatment as it travels along the sanitation system 30 enclosing conduits 31 arranged to "penetrate" the lateral wall 11 in the longitudinal direction.

A heating jacket or other heating device (Figs. 3, 5B) provided within the sanitary system 30 advantageously includes heat transfer means in communication with the heat generating device. Preferably, the heat required for purification is obtained from the heat recovery and circulation system 44 (FIG. 5B) described further below. Thus, heating can be achieved via liquid circulation. Additionally or alternatively, heat transfer can be mediated by means of an external heat exchanger or heat pump. Exemplary locations of heat exchanger 50 are shown on Figures 3 and 5B.

The reactor arrangement 100 also includes a temperature regulation system 40 configured to regulate the temperature in the one or more tanks 101 . The system 40 includes a plurality of internal tubes 41, 42 configured to traverse through the lateral walls 11 and/or the base 12 of the tank in a longitudinal direction, and to convey temperature regulating fluid along the internal tubes accordingly (Fig. 4A to Figure 4C). By means of the temperature regulation system 40, the temperature within the reactor tank 101 is maintained at a level suitable for the normal functioning of the bacterial population essential for anaerobic digestion.

In order to accommodate the temperature adjustment device 40 into the reactor tank 101 , the elements 11 , 11A forming the lateral walls and/or the base element(s) 12 can be provided as pre-formed with a plurality of hollow tubular tubes 40 hollow core concrete slab. The diameter of the tube forming the device 40 is preferably smaller than the diameter of the tube forming the conduit 31 . For the sake of clarity, reference numeral 41 further refers to a tube arranged in the side wall 11 , while reference numeral 42 refers to a tube arranged in the base element 12 . Tubes 41 and 42 are provided within the temperature adjustment system 40 .

In some embodiments, the tubes 41 , 42 further comprise (eg, metal) conduits that are enclosed in forming the lateral walls 11 , 11A and/or the base (central) element(s) 12 or inside lined/coated concrete slabs to reduce wear on the concrete slabs. A coating, such as eg a metallic coating, is preferably applied before the blocks 11 , 11A, 12 are assembled.

The temperature adjustment fluid is a glycol compound such as, for example, ethylene glycol or propylene glycol. Alternatively, the temperature adjustment liquid may be water. By circulating the heating fluid through the pipes 41, 42, the temperature within the reactor tank 101 is kept high enough for mesophilic digestion (10°C to 8°C, preferably 30°C to 42°C), or for thermophilic digestion (42°C to 97°C, preferably within 42°C to 66°C, and in some cases within 43°C to 55°C).

The tubes 41, 42 forming the temperature regulation system 40 may be arranged into a substantially closed-loop recirculation path, wherein the temperature regulation fluid flows between the tubes 41, 42 with the heat recovery and circulation system 44 described further below, and optionally with at least at least recirculation between an external heat source (not shown). To create a recirculation path, in some configurations, the head end wall element or the head end L-shaped profile may have pre-formed turns and/or pipe bends disposed therein.

Referring to FIG. 6 , in several configurations, an inner tube 43 is disposed inside the drive rod 23 of each agitator, the inner tube 43 being configured to convey the temperature regulating fluid along the inner tube 43 . As mentioned above, the stirrer shaft(s) are provided as a hollow interior tubular body. Tubes 43 formed inside each of the agitator shafts are used to transport a temperature-adjusting fluid such as glycol or water along the tubes and provide additional heating for the substrate agitated in the reactor tank 101 .

A temperature regulating fluid (eg, glycol) is fed into pipe 43 at discharge side 17 . The fluid circulates and returns via the shaft 23 in the direction of the entry end 16 (indicated by arrows in FIG. 6 ). The shaft is preferably equipped with a rotary coupling at least at the discharge end 17 to allow the temperature regulating fluid to be directed into the tube 43 during rotation of the agitator shaft 22 .

Providing a temperature-adjusting liquid inside the shaft allows microbial activity to be equalized over the entire length of the reactor tank.

Further preferably, via several local temperature control units (not shown) and/or via a central heat distribution and control unit 51 ( FIG. 7 ) the arrangement and arrangement within the tubes 41 arranged in the lateral walls of the tank 101 can be independently adjusted Temperature conditions within the tube 42 in the base of the tank. Providing independent temperature control for each of the walls and bottom of the reactor tank 101 allows for proper distribution of thermal energy to locations within the tank where material deposits and deposits are most likely to occur, such as distributing thermal energy where substrates are moving slowly or otherwise obstructed.

In a similar manner, the temperature conditions within the tube(s) 43 inside the stirrer shaft(s) can be controlled independently of the temperature in tubes 41 and/or 42 .

The temperature regulation system 40 is preferably arranged in communication with a heat recovery and circulation system 44 including at least one heat exchanger 50 (FIGS. 3, 7). Excess thermal energy released via temperature regulation system 40 and/or sanitation system 30 may be further supplied to pretreatment facility 401 and/or extracted for further utilization.

In some configurations, tubes 41, 42 and 43 establish temperature regulation system 40 and provide (internal) temperature regulation fluid circulation within the reactor tank. Reactor 100 also includes a so-called external fluid circulation system configured to circulate (recirculate) fluid substantially outside the reactor tank, also referred to as heat recovery and circulation ( recycling)/reuse system 44.

System 44 configured for efficient recovery and reuse of heat generated during anaerobic digestion forms one of the core features of reactor 100 (FIG. 5B, FIG. 7). System 44 is preferably configured to transfer heat from the output side (plant 201 ) to the feedstock supply side (plant 401 ). Additionally, the heat recovery and circulation (recirculation) system 44 is preferably configured to communicate with the "internal" temperature regulation system 40 and to direct the heat thus recovered to the system 40 and optionally to the sanitary system 30 .

FIG. 7 shows an exemplary configuration of the systems 40 , 44 within the reactor 100 . The temperature regulation system 40 comprising the tubes 41, 42, 43 and incorporating the reactor tanks 101-1, 101-2 is shown in dashed lines. The heat recovery and circulation (recirculation) system 44 is provided as a network of interconnected conduits or pipes configured to direct the heat obtained during the anaerobic digestion (17, 201) towards the pretreatment facility 401 and the pretreatment Various devices 301 , 302 , 401 in facility 401 pass. As mentioned above, heat transfer occurs via the liquid circulation.

We note here that systems 40 and 44 form an integrated ensemble for heat recovery, circulation and temperature control. In this disclosure, the systems are designated by different reference numerals to provide the reader with a better understanding of the heat recovery function of the reactor arrangement 100 .

Each of the systems 40 , 44 advantageously includes several local heat exchange units 50 and temperature control units such as thermostats (not shown) to detect and adjust temperature conditions in the reactor arrangement 100 .

Integrated control of the systems 40, 44 is achieved via a central heat distribution and control unit 51 (FIG. 7). Preferably, at least one heat exchanger unit 50 is provided within the heat recovery and circulation system 44 to mediate heat transfer between the tank(s) 101 (the digestate discharge side) and the pretreatment facility 401 (Fig. 5B). On Figure 5B, the heat transfer from the output (plant 201) to the input (plant 401) is shown by arrows (T).

Accordingly, one or more heat exchanger units 50 within the system 44 are provided for transferring the thermal energy obtained from the anaerobic digestion process in the at least one reactor tank 101 to the pretreatment facility 401 . Via said heat exchanger unit(s) 50, heat transfer can be mediated (in the order indicated) between the aftertreatment facility 201/sanitation system 30, the temperature regulation device 40 and the pretreatment facility 401. Heat extracted from facility 401 may be stored, transferred for further use and/or returned to the output side (plant 201).

In some cases, the reactor 100 also includes a substrate recycling appliance (not shown) for reintroducing a portion of the digested substrate into the reactor tank 101 . This fraction (the inoculum) is allowed to separate before the digested substrate enters the sanitation system 30 . Preferably, at least one third of the digested substrate is returned to reactor 100 to maintain a stable bacterial population in the reactor tank. The one or more conduits configured to transport the inoculum back into the reactor tank are not subjected to thermal treatment.

The reactor 100 is configured for anaerobic digestion treatment of organic substrates, wherein the content of dry matter (solid matter) is 0 to 80 percent by weight (wt %), preferably 0 to 45 wt %. In most cases, the DM content of the organic matrix inside the reactor tank 101 is in the range of 10 wt % to 35 wt %; however, the above range may vary on a case-by-case basis. In some embodiments, the preferred content of dry matter in the feedstock is about 35 wt%. The organic matrix entering the reactor tank 101 remains in the solid state, ie the dry matter is in the range of 30 wt% to 40 wt% mentioned above. In special cases, where the dry matter content equals or exceeds 50 wt%, it is necessary to dilute the reaction matrix. The organic matrix with about 35 wt% DM dissolves as it travels along the length of the reactor tank 101, whereby the digested product D contains about 25 wt% dry matter.

In some aspects of the invention, the use of the reactor 100 for the anaerobic digestion of organic waste is provided.

In another aspect, the use of the reactor 100 for the production of biogas is provided. As mentioned above, the anaerobic digestion process mediated by microbial activity results in the production of biogas. Biogas is a mixture of predominantly methane (50-70%) and carbon dioxide (30-40%) with traces of ammonia ( _NH3 ) and _hydrogen sulfide (H2S). The biogas obtained from the reactor 100 is advantageously directed for further refining, eg for the production of biofuels.

Figure 5A shows a transverse section of the anaerobic digestion reactor arrangement 100 along an (imaginary) longitudinal axis of symmetry, while Figure 5B shows an exemplary layout of the arrangement 100 viewed from the top. Thus, the reactor arrangement includes at least one reactor tank 101 (three tanks 101-1, 101-2 and 101-3 are shown on Figure 5B), a post-processing facility with the heat transfer equipment discussed above 201 , and a pretreatment facility 401 comprising at least one feed tank 301 advantageously equipped with a cover 311 and several feed supply means 302 , 402 configured to convey the raw material in the direction of the tank 101 .

Feed tank(s) 301 may be configured to receive either fully raw ("raw") feedstock or pre-comminuted feedstock. Where applicable, pre-comminution is preferably performed in a conventional pulverizer or mill prior to loading the feedstock into the feed tank(s) 301 . Desirably, the size of discrete aggregates, such as feedstock clumps and/or solid residues/inorganics, entering the reaction space 101 does not exceed the size of two clenched fists (150mm to 200mm). Whether or not the organic waste to be processed by the reactor 100 contains or is expected to contain larger aggregates and/or solid debris (eg, stone, gravel, or beef bones), such waste should be pre-comminuted in the manner described above.

On the other hand, considering the above-described embodiments, whether the feedstock to be processed is substantially homogeneous and/or does not contain oversized aggregates, the reactor 100 may be loaded with a certain amount of indigestible residues impure substrates of substances such as sand, stones and various plastic contaminants.

The substantially impure feed is pretreated in the first feed supply means 302 and the second feed supply means 402 before entering the reactor tank 101 . The second means 402 for conveying the feedstock into the reaction space 101 are preferably configured as conveyors, eg scraper conveyors, in the same manner as the discharge means 203 discussed above. Preferably, the device 402 is configured to adjust the temperature of the organic substrate entering the one or more reactor tanks 101 to match the temperature maintained in the tanks. The temperature-regulated feedstock delivered by the feed supply means 402 into the reactor tank(s) 101 is received into the reaction space through the inflow port 18 provided at the inlet end 16 .

In most cases, the feed supply device 402 is configured to thermally treat the organic feedstock by heating, since the temperature maintained inside the reactor tank 101 (especially the temperature maintained primarily by the temperature adjustment device 40) compared to the untreated feedstock ) is usually higher. Accordingly, the need to adjust the temperature within the reactor tank 101 arises from the necessity to maintain the vital function and activity of the microorganisms present. In some exceptional cases, facility 401 may be configured to cool incoming feedstock.

The means 302 configured to convey the raw material towards the storage (feed) tank 301 towards the heated conveyor 402 are preferably configured as screw conveyors or piston pumps.

It will be apparent to those skilled in the art that, as technology advances, the basic idea of the present invention is intended to cover various modifications included within the spirit and scope of the present invention. Therefore, the invention and its embodiments are not limited to the examples described above; rather, the invention and its embodiments may vary generally within the scope of the appended claims.

Claims (17)

1. A reactor arrangement (100) for anaerobic digestion of biodegradable organic substrates, the reactor arrangement comprising:

at least one reactor tank (101) extending horizontally, the tank (101) having an inflow port (18) at an inlet end (16) and at least one outflow port at a discharge end (17) opposite the inlet end (16),

at least two agitators (22) extending longitudinally, the agitators (22) being arranged side by side within the interior (10) of the tank (101), and

a temperature regulation system (40) configured to regulate the temperature in the at least one tank (101) and comprising a plurality of internal tubes (41, 42) configured to traverse in a longitudinal direction through lateral walls and/or a base of the at least one tank and to convey a temperature regulation fluid along the plurality of internal tubes.

2. The reactor arrangement (100) of claim 1, configured to transport biodegradable organic substrates along the length of the tank (101) towards the discharge end such that: digested organic matrix is discharged from the tank (101) through a main outflow port (19) and indigestible residue is discharged through at least one auxiliary outflow port (20, 21).

3. The reactor arrangement (100) according to any one of the preceding claims 1 or 2, wherein lateral walls defining the interior (10) of the tank (101) in a longitudinal direction are inclined, such that one or more inclined elements (S) are formed along the entire length of the tank at the intersection between the lateral walls and the bottom.

4. The reactor arrangement (100) according to any preceding claim, wherein each lateral wall comprises one or more substantially flat panels (11A) having the inclined elements (S) provided as separate modules (11B).

5. The reactor arrangement (100) according to any preceding claim, wherein each agitator (22) comprises a drive rod (23), the drive rod (23) having a number of blades (24) mounted to the drive rod (23).

6. The reactor arrangement (100) according to any preceding claim, wherein inside the drive rod (23) of the stirrer there is arranged the following inner tube (43): the inner tube (43) is configured to convey a temperature-adjusting fluid along the inner tube (43).

7. The reactor arrangement (100) according to any preceding claim, wherein the temperature conditions within the tubes (41) arranged in the lateral walls of the tank (101) and within the tubes (42) arranged in the base of the tank are independently adjustable.

8. The reactor arrangement (100) further comprising a pre-treatment facility (401) having at least one feed supply means (402), the feed supply means (402) being configured to adjust the temperature of the organic substrate entering the at least one reactor tank (101) to coincide with the temperature maintained in the tank (101).

9. The reactor arrangement (100) according to any preceding claim, further comprising a sanitation system (30) for thermally decontaminating digested substrate.

10. The reactor arrangement (100) according to any preceding claim, wherein the sanitation system (30) is provided in a post-treatment facility (201) arranged downstream of the at least one tank (101).

11. The reactor arrangement (100) according to any preceding claim 1 to 9, wherein the sanitation system (30) comprises at least one enclosed conduit (31) configured to traverse in a longitudinal direction through the lateral wall and/or the base of the tank (101) and to receive digested substrate discharged through the main outflow port (19).

12. The reactor arrangement (100) according to any preceding claim, further comprising a heat recovery and recycling system (44) configured to recover heat generated in the at least one tank (101) during anaerobic digestion and to direct the heat thus recovered to the pretreatment facility (401).

13. The reactor arrangement (100) according to any preceding claim, wherein the heat recovery and recycle system (44) is further configured to direct the recovered heat to the temperature regulation system (40) and optionally to the sanitation system (30).

14. The reactor arrangement (100) according to any preceding claim, wherein the heat recovery and recycle system (44) comprises at least one heat exchanger unit (50), the heat exchanger unit (50) for mediating heat transfer between the at least one tank (101) and the pretreatment facility (401).

15. The reactor arrangement (100) according to any one of the preceding claims, comprising several tanks (101) arranged next to each other.

16. Use of the reactor arrangement (100) according to claims 1 to 15 for anaerobic digestion of organic waste.

17. Use of a reactor arrangement (100) according to claims 1 to 15 for biogas production.

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