Dry methane fermentation tank and dry methane fermentation system

Abstract

The present invention provides a dry methane fermentation tank with excellent durability and heat retention, and a dry methane fermentation system equipped with the said dry methane fermentation tank. [Solution] A dry methane fermentation tank has a fermentation tank body for carrying organic resources and / or raw materials derived from organic resources in a containment space and performing dry methane fermentation, the fermentation tank body includes a partition member that separates the containment space from the outside of the fermentation tank body, the partition member has a base material and a polyurea resin layer provided on the side of the base material that faces the containment space and at least a portion of the surface facing the containment space.

Description

[Technical Field]

[0001] This invention relates to a dry methane fermentation tank and a dry methane fermentation system. [Background technology]

[0002] To effectively utilize limited resources and create a prosperous society, solutions to many social problems, such as preventing global warming and ensuring a stable energy supply, are being considered. Among these social problems, waste management has become one of the most important issues to address in recent years. Organic waste, including food waste, agricultural and marine products, and livestock excrement, amounts to over 200 million tons annually. Burial requires vast amounts of land, and incineration incurs enormous disposal costs.

[0003] Methane fermentation technology is a technique that uses methanogenic bacteria to produce biogas containing useful gases such as methane and hydrogen from organic matter. Methane and hydrogen can be used as energy by combustion and are also useful as raw materials for chemical products. By applying such methane fermentation technology to organic waste, it is possible to convert waste into valuable resources, thereby reducing the burden associated with disposal and carbon dioxide emissions associated with incineration. Furthermore, if methane fermentation is carried out near the site where the organic waste is generated, local production and consumption of resources becomes possible, eliminating the costs and burdens associated with transporting organic waste and the obtained resources.

[0004] This methane fermentation technology includes wet methane fermentation, which is carried out at a relatively low solid content concentration, for example, 10% or less, and dry methane fermentation, which is carried out at a relatively high solid content concentration, for example, 15% to 45%.

[0005] Wet methane fermentation has advantages such as simple equipment and low maintenance costs, but it also has disadvantages compared to dry methane fermentation, such as lower gas production, larger wastewater volume, and higher treatment costs. On the other hand, dry methane fermentation produces a large amount of biogas, but it also has disadvantages such as high power consumption and relatively complex equipment.

[0006] Incidentally, a wide variety of materials are introduced into dry methane fermentation tanks used for dry methane fermentation. Because the solid content of the materials to be fermented is relatively high, the materials are subjected to physical forces from the dry methane fermentation tank during their introduction and discharge, as well as during fermentation. Furthermore, the pH and other properties of the fermented material in the dry methane fermentation tank change depending on the type of material being fermented. In addition, during dry methane fermentation, the fermented material and the dry methane fermentation tank containing it are exposed to relatively high temperatures.

[0007] Thus, dry methane fermentation tanks require excellent durability because they are exposed to harsh environmental conditions during long-term fermentation. Patent Document 1 proposes a dry methane fermentation tank made of concrete. [Prior art documents] [Patent Documents]

[0008] [Patent Document 1] Japanese Patent Publication No. 2005-230624 [Overview of the project] [Problems that the invention aims to solve]

[0009] As mentioned above, dry methane fermentation tanks require excellent durability because they are exposed to harsh environmental conditions during long-term fermentation. On the other hand, to increase the durability of dry methane fermentation tanks, it is generally necessary to construct the tank with concrete through large-scale construction work, as described in Patent Document 1, or to construct the tank with highly durable materials such as stainless steel.

[0010] On the other hand, the method described above requires significant costs for the manufacture and installation of dry methane fermentation tanks. The materials used for methane fermentation are by-products and waste generated in each region and location. Considering the transportation costs and energy required to transport the materials to the methane fermentation facility, it is preferable to install a methane fermentation facility at each location where the materials are generated. However, in such cases, methane fermentation facilities are often small in scale, making it difficult to justify the large costs of their installation.

[0011] Furthermore, dry methane fermentation is carried out at relatively high temperatures. Currently, heating is generally performed using heaters or similar devices to maintain the fermentation temperature in dry methane fermentation. However, heating by heaters consumes energy itself, which ultimately reduces the energy efficiency of dry methane fermentation, so it is preferable to minimize it as much as possible. From this perspective, if the dry methane fermentation tank has excellent heat retention, it is possible to reduce the amount of heating required by heaters. However, conventional fermentation tanks do not adequately consider the heat retention of the tank itself.

[0012] Therefore, the object of the present invention is to provide a dry methane fermentation tank that is highly durable and has excellent heat retention properties, and a dry methane fermentation system equipped with said dry methane fermentation tank. [Means for solving the problem]

[0013] As a result of diligent research to achieve the above objective, the inventors of the present invention discovered that even if the main constituent material of the dry methane fermentation tank is an inexpensive material with insufficient durability, the durability of the dry methane fermentation tank can be significantly improved by coating at least a part of the inner wall of the dry methane fermentation tank with polyurea resin. Furthermore, they found that this dry methane fermentation tank has excellent heat retention properties. As a result of further research, they arrived at the present invention.

[0014] The gist of this invention is as follows: [1] Having a fermentation tank body for carrying out dry methane fermentation by storing organic resources and / or raw materials derived from organic resources in a containment space, The fermentation tank body includes a partitioning member that partitions the accommodation space from the outside of the fermentation tank body. The partitioning member has a base material and a polyurea resin layer provided on the accommodation space side of the base material and disposed on at least a part of the surface facing the accommodation space, and is a dry methane fermentation tank. [2] The dry methane fermentation tank according to [1], wherein the partitioning member further has a heat insulation layer. [3] The dry methane fermentation tank according to [2], wherein the heat insulation layer is disposed between the polyurea resin layer and the base material. [4] The dry methane fermentation tank according to [2] or [3], wherein the heat insulation layer is a foamed resin layer. [5] The dry methane fermentation tank according to any one of [1] to [4], wherein the partitioning member includes a metal material. [[ID=I3]][6] The dry methane fermentation tank according to any one of [1] to [5], wherein the partitioning member includes a steel material. [7] The dry methane fermentation tank according to [6], wherein the steel material includes carbon steel. [8] The dry methane fermentation tank according to any one of [1] to [7], wherein the partitioning member includes a wall member and a ceiling member, and at least a part of the surface of the wall member and / or the ceiling member facing the accommodation space is coated with the polyurea resin layer. [9] The dry methane fermentation tank according to any one of [1] to [8], wherein the fermentation tank body is configured using a container.

[10] The dry methane fermentation tank according to any one of [1] to [9], further having a fluid discharge nozzle attached to the fermentation tank body and discharging fluid toward the accommodation space.

[11] A dry methane fermentation system including the dry methane fermentation tank according to any one of [1] to

[10] .

[12] The dry methane fermentation system according to

[11] , including a plurality of the dry methane fermentation tanks.

Advantages of the Invention

[0015] As described above, the present invention provides a dry methane fermentation tank with excellent durability and heat retention, and a dry methane fermentation system equipped with the dry methane fermentation tank. [Brief explanation of the drawing]

[0016] [Figure 1] Figure 1 is a diagram showing the configuration of a dry methane fermentation system according to the first embodiment of the present invention. [Figure 2] Figure 2 is a schematic longitudinal cross-sectional view showing a dry methane fermentation tank according to the first embodiment of the present invention. [Figure 3] Figure 3 is a schematic cross-sectional view showing a portion of the fermentation tank body of the dry methane fermentation tank shown in Figure 2. [Figure 4] Figure 4 is a diagram showing the configuration of a dry methane fermentation system according to a second embodiment of the present invention. [Figure 5] Figure 5 is a schematic cross-sectional view showing a dry methane fermentation tank according to a second embodiment of the present invention. [Figure 6] Figure 6 is a schematic cross-sectional view of the fermentation tank body of the dry methane fermentation tank shown in Figure 5, along line xx. [Figure 7] Figure 7 is a schematic cross-sectional view showing a portion of a dry methane fermentation tank according to a modified example of the present invention. [Figure 8] Figure 8 is a schematic cross-sectional view showing a portion of a dry methane fermentation tank according to another modification of the present invention. [Figure 9] Figure 9 is a schematic cross-sectional view showing a portion of a dry methane fermentation tank according to another modification of the present invention. [Modes for carrying out the invention]

[0017] Hereinafter, preferred embodiments of the dry methane fermentation tank and dry methane fermentation system according to the present invention will be described in detail with reference to the drawings.

[0018] <1. First Embodiment> Figure 1 is a schematic diagram of the dry methane fermentation system according to the first embodiment of the present invention, Figure 2 is a schematic longitudinal cross-sectional view showing the dry methane fermentation tank according to the first embodiment of the present invention, and Figure 3 is a schematic cross-sectional view showing a part of the fermentation tank body of the dry methane fermentation tank shown in Figure 2. In the figures, the size of each component is exaggerated for the sake of clarity, and the actual proportions and sizes of each component are not shown.

[0019] The dry methane fermentation system 1 shown in Figure 1 is a device for obtaining biogas containing methane by fermenting organic resources 200 using dry methane fermentation. Methane fermentation is one method of fermenting biologically derived organic resources under anaerobic conditions to recover fermentation heat and methane gas, which are then used as energy or raw materials for chemicals. Furthermore, in the dry methane fermentation system 1, since dry methane fermentation is performed, methane fermentation takes place at a relatively high solid content concentration, for example, between 15% by mass and 45% by mass.

[0020] Generally, organic resources 200 are waste materials such as livestock manure and food waste that have no other use. Examples of organic resources 200 used in this embodiment include household food waste (e.g., food waste), household waste such as paper waste, sewage sludge, animal-derived waste such as livestock manure, wood chips (e.g., waste wood, sawdust, bark, packaging waste, planks, waste chips, felled wood (thinned wood, etc.), pruned branches, stumps), crop residues (leaf removal, fruit thinning, grass cuttings, etc.), and plant-derived waste such as spent mushroom substrate. Only one of these may be used as organic resources 200, or two or more may be combined and used as organic resources 200.

[0021] The dry methane fermentation system 1 comprises a crusher 11, a kneader 13, a dry methane fermentation tank 100, a desulfurization device 15, a gas storage tank 17, and a re-bacteria tank 19.

[0022] The crusher 11 crushes the organic resources 200 into pieces of appropriate size. Examples of crushers 11 include cutting chippers, cutter knife chippers, hammer crushers, chain crushers, single-shaft crushers, and multi-shaft crushers (e.g., twin-shaft crushers). One of these can be used alone or in combination of two or more. The organic resources 200 crushed in the crusher 11 are transferred to the kneader 13. If only organic resources 200 of an appropriate size are used, the crusher 11 can be omitted.

[0023] The kneader 13 is a device that kneads the crushed and / or uncrushed organic resources 200 obtained in the crusher 11 with the starter culture. Examples of kneaders 13 include single-screw mixers, multi-screw mixers (e.g., twin-screw mixers), open roll mixers, pressure kneaders, internal mixers, Banbury mixers, etc., and one of these can be used alone or in combination of two or more. The organic resources 200 mixed with the starter culture in the kneader 13 are transferred to the dry methane fermentation tank 100. In this embodiment, the starter culture is made from the reclaimed bacteria obtained as fermentation residue after dry methane fermentation and is introduced into the kneader 13.

[0024] The dry methane fermentation tank 100 shown in Figure 2 is a tank for carrying organic resources 200 and / or their processed products (raw materials derived from organic resources) and performing dry methane fermentation. The dry methane fermentation tank 100 has a fermentation tank body 110, a biogas recovery nozzle 120, a fluid discharge nozzle 130, and a heating device 140. The material to be subjected to methane fermentation treatment in the dry methane fermentation tank 100 may be either organic resources 200, raw materials derived therefrom (raw materials derived from organic resources, processed products), or both, but in the following explanation, only organic resources 200 will be described as a representative example for the purpose of simplifying the explanation.

[0025] The fermentation tank body 110 is airtight and pressure-resistant, and in its containment space 111, it serves as a fermentation tank for fermenting organic resources 200 and other materials to be fermented, as well as a containment container for various equipment. In this embodiment, the fermentation tank body 110 is a roughly rectangular parallelepiped container and is a horizontal fermentation tank that is long in the horizontal direction. The fermentation tank body 110 is composed of various partition members such as wall members 113, ceiling members 115, floor members 117, opening and closing doors 119, and frame members (not shown) that ensure the physical strength of the fermentation tank body 110.

[0026] Various partitioning members such as wall members 113, ceiling members 115, floor members 117, and opening / closing doors 119 separate the inside and outside of the fermentation tank body 110, forming a containment space 111 inside the fermentation tank body 110 that is covered by the partitioning members. The containment space 111 houses the material to be fermented, such as organic resources 200, and various equipment such as heating devices 140. Here, the containment space 111 is the space in which the material to be fermented is subjected to methane fermentation.

[0027] The floor member 117 is positioned horizontally below the dry methane fermentation tank 100. The three wall members 113 and the opening / closing door 119 are positioned perpendicularly from the floor member 117, surrounding the containment space 111 from the side. Specifically, two of the wall members 113 are positioned along the longitudinal direction, and one of the wall members 113 and the opening / closing door 119 are positioned to seal the two wall members 113 along the longitudinal direction at their longitudinal ends. The ceiling member 115 is joined to the wall members 113 and the opening / closing door 119 to seal the upper opening formed by the wall members 113 and the opening / closing door 119. The opening / closing door 119 is openable and closable, allowing for the loading and unloading of organic resources 200 and their fermented products.

[0028] Here, as shown in Figure 3, each partition member constituting the fermentation tank body 110 is formed by laminating a base material 1101, a foamed resin layer 1103, and a polyurea resin layer 1105 in this order from the outside toward the containment space 111. For example, specifically, as shown in Figure 3, the wall member 113 has a base material 1101, a polyurea resin layer 1105 covering its containment space 111 side, and a foamed resin layer 1103 positioned between the base material 1101 and the polyurea resin layer 1105. In this embodiment, the entire surface of each partition member facing the containment space 111 is covered with the polyurea resin layer 1105.

[0029] Thus, by coating the inner surface of the partition members of the fermentation tank body 110 with polyurea resin, the durability of the fermentation tank body 110 is improved. To explain in more detail, a wide variety of materials to be fermented (organic resources 200) are introduced into the dry methane fermentation tank 100 for dry methane fermentation. For this reason, the pH and other properties of the fermented material in the dry methane fermentation tank 100 also change depending on the type of material being fermented. Specifically, depending on the type of material, the fermented material can exhibit an acidic to alkaline pH of about 3 to 9. Furthermore, during dry methane fermentation, the fermented material and the dry methane fermentation tank 100 containing it are exposed to relatively high temperatures, for example, 30 to 80°C, during the fermentation process.

[0030] In environments with a wide range of acidic to alkaline pH and high temperatures, the materials constituting a dry methane fermentation tank are generally prone to deterioration such as corrosion, swelling, and decomposition. While it is possible to construct the fermentation tank body of a dry methane fermentation tank from stainless steel or concrete, this would result in high installation costs due to the material costs and extensive construction expenses. In contrast, polyurea resin is chemically stable even in the harsh environments described above. Therefore, by using polyurea resin as the material for the inner surface of the fermentation tank body 110, chemical deterioration of the fermentation tank body 110 caused by the fermentation of the fermented material can be suppressed. This is thought to be partly because polyurea resin is a polymer composed of polyamine and isocyanate, and the polymer chain of the polyurea resin has few oxygen atoms, making hydrolysis less likely.

[0031] Furthermore, depending on the type, the organic resources 200 may include relatively hard materials such as wood chips. Such materials may cause physical damage to the fermentation tank body 110 by scratching or rubbing against the inner wall of the fermentation tank body 110 when they are added or removed after fermentation. However, polyurea resin has excellent abrasion resistance, and by coating the inner surface of the fermentation tank body 110 with it, damage to the fermentation tank body 110 can be prevented.

[0032] Furthermore, polyurea resin possesses excellent physical strength, such as high tensile strength, tear strength, and elasticity, and by coating the inner surface of the fermentation tank body 110, the physical strength (mechanical strength) and physical durability of the fermentation tank body 110 itself can be improved.

[0033] As described above, by coating the surface of the partition members of the fermentation tank body 110 facing the containment space 111 with polyurea resin, the chemical and physical durability of the fermentation tank body 110 can be improved simultaneously. Therefore, even if the base material of the partition members constituting the fermentation tank body 110 is a relatively inexpensive and less durable material, such as general steel (steel plate), the durability of the fermentation tank body 110, and consequently the dry methane fermentation tank 100, can be improved.

[0034] In addition, compared with inorganic materials such as metal materials and concrete, the polyurea resin has a low thermal conductivity and high heat insulation properties. For example, the thermal conductivity of metal materials such as steel plates and stainless steels is in the range of more than a dozen W / (m·K) to several hundred W / (m·K), and the thermal conductivity of concrete is about 1.5 W / (m·K). In contrast, the thermal conductivity of the polyurea resin is about 0.14 W / (m·K), although it depends on its composition. By arranging the polyurea resin layer 1105 containing such a polyurea resin on the inner surface side of the partitioning member, the outflow of heat from the accommodation space 111 of the fermentation tank body 110 is prevented. As a result, the heat retention property of the entire fermentation tank body 110 is improved.

[0035] The above-mentioned polyurea resin is a compound mainly formed by the chemical reaction of an isocyanate compound composition (main agent) and an amine compound composition (curing agent). Examples of the polyurea resin include HiChem TM 11-70, eXtreme TM HP11-50, eXtreme TM HP11-70, eXtreme TM HP11-50FR, eXtreme TM HP11-50GTS, ECO-COAT TM , TuffGripp TM , SolarMax TM , HYBRID TM , Duratite TM 2185P, FastFloor TM , Chrome TM (All of the above are manufactured by Rhino Linings Corporation) etc. can be mentioned.

[0036] The isocyanate compound composition as the main component contains at least an isocyanate compound. Examples of isocyanate compounds include aliphatic isocyanates and aromatic isocyanates, which can be used individually or in combination of two or more. Examples of aliphatic isocyanates include 1,6-hexamethylene diisocyanate, 1,5-pentamethylene diisocyanate, 1-isocyanate-3-isocyanate-methyl-3,5,5-trimethylcyclohexane, dicyclohexylmethane 4,4'-diisocyanate, xylylene diisocyanate, cyclohexane diisocyanate, 1,4-bis(isocyanate-methyl)cyclohexane, and tetramethylxylylene-diisocyanate. Furthermore, examples of aromatic isocyanate compounds include 2,4-trylene-diisocyanate, 2,6-trylene-diisocyanate, 2,2'-methylenebis(phenylisocyanate), 2,4'-methylenebis(phenylisocyanate), 4,4'-methylenebis(phenylisocyanate), p-phenylene-diisocyanate, dimethylbphenylene diisocyanate, naphthalene-1,5-diisocyanate, and 4,4-dibenzyl diisocyanate.

[0037] Furthermore, the isocyanate compound composition may contain compounds other than the isocyanate compounds described above. For example, the isocyanate compound composition may contain a carbodiimide-modified product of the isocyanate compound described above (a carbodiimide-containing isocyanate). In addition, the isocyanate compound composition may contain oligomeric reaction products of the isocyanate compound and the polyol described later.

[0038] Among those described above, the isocyanate compound composition preferably contains an aromatic isocyanate, more preferably one or more selected from the group consisting of 2,4-trylene-diisocyanate, 2,6-trylene-diisocyanate, 2,2'-methylenebis(phenylisocyanate), 2,4'-methylenebis(phenylisocyanate), 4,4'-methylenebis(phenylisocyanate), p-phenylene-diisocyanate, dimethylbphenylenediisocyanate, naphthalene-1,5-diisocyanate, and 4,4-dibenzyldiisocyanate, and even more preferably one or more selected from the group consisting of 2,2'-methylenebis(phenylisocyanate), 2,4'-methylenebis(phenylisocyanate), and 4,4'-methylenebis(phenylisocyanate).

[0039] Furthermore, the amine compound composition as a curing agent includes at least an amine compound having active hydrogen. Examples of such amine compounds include hydrazine, ethylenediamine, 4,4'-methylene-bis-(2-chloroaniline), dimethylthiotoluenediamine, diethylthiotoluenediamine, trimethylene glycol di(p-aminobenzoate), 4,4'-methylene-bis-(3-chloro-2,6-diethylaniline), 4,4'-methylene-bis-(2,6-diethylaniline), triisopropanolamine, p-bis(aminocyclohexyl)methane, naphthalene-1,5-diamine, xylylenediamine, phenylenediamine, toluene-2,4-diamine, t-butyltoluenediamine, 1,2-bis(2-aminophenylthioethane), etc., and one of these can be used alone or in combination of two or more.

[0040] Furthermore, the amine compound composition may also contain a polyol compound. Examples of such polyol compounds include alkylene glycol compounds such as ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, 1,2-propanediol, 1,3-propanediol, dipropylene glycol, tripropylene glycol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 1,5-pentanediol, 1,5-hexanediol, 1,6-hexanediol, 2,5-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, and 1,10-decanediol, as well as diethylene glycol, dipropylene glycol, dihexamethylene ether glycol, and ditetramethylene ether glycol. Examples include ether condensation oligomers of alkylene glycol compounds such as triethylene glycol, tripropylene glycol, trihexamethylene ether glycol, and tritetramethylene ether glycol; polyether polyols such as polyethylene glycol, polyoxypropylene glycol, polyhexamethylene ether glycol, and polytetramethylene ether glycol; polyester polyols such as polycaprolactone polyol and polyethylene adipate; glycerin, ditrimethylolpropane, trimethylolpropane, pentaerythritol, dihydroxymethylpropionic acid, and condensates of one or more of these compounds, which can be used individually or in combination of two or more.

[0041] Furthermore, it is preferable that the polyol compound contains a compound that includes an ether bond. Compared to an ester bond, the ether bond is chemically more stable and can prevent hydrolysis of the polyurea resin layer 1105 within the fermentation tank body 110, thereby preventing deterioration of the polyurea resin layer 1105 when dry methane fermentation is carried out for a long period of time. Examples of compounds containing such ether bonds include ether condensation oligomers of alkylene glycol compounds and polyether polyols.

[0042] In particular, the amine compound composition preferably contains a compound having three or more functional groups (hydroxyl groups) as a polyol. Such a compound can crosslink in the formed polyurea resin to form a three-dimensional network structure. As a result, the physical strength of the resulting polyurea resin layer 1105 is improved. Examples of such compounds having three or more functional groups (hydroxyl groups) include glycerin, ditrimethylolpropane, trimethylolpropane (TMP), pentaerythritol, and condensates of these with the polyol compounds mentioned above, such as polyoxyethylene-polyoxypropylene glyceryl ether and polyoxypropylenetriol.

[0043] Furthermore, the amine compound composition may also contain an inorganic filler. The inorganic filler improves the abrasion resistance of the polyurea resin layer 1105 by improving the hardness of the formed polyurea resin layer 1105. Examples of such inorganic fillers include titanium dioxide, zeolite, silica, kaolin, clay, talc, diatomaceous earth, calcium silicate, magnesium silicate, mica, etc., and one of these can be used alone or in combination of two or more.

[0044] The polyurea resin layer 1105 can be formed, for example, by mixing the isocyanate compound composition and the amine compound composition described above and spraying the mixture onto the target portion of the partition member.

[0045] Furthermore, the thickness of the polyurea resin layer 1105 is not particularly limited, but for example, it is 0.10 mm or more and 20 mm or less, preferably 0.50 mm or more and 10 mm or less. By keeping the thickness of the covering polyurea resin layer 1105 within the above range, it is possible to suppress the excessive use of polyurea resin while fully obtaining the effects of the polyurea resin described above.

[0046] The foamed resin layer 1103 is an insulating layer, and in this embodiment, it suppresses heat exchange between the base material 1101 and the polyurea resin layer 1105. This further improves the heat retention of the fermentation tank body 110, suppresses heating by the heating device 140 during dry methane fermentation, and reduces energy consumption due to heating. As a result, the overall energy efficiency of dry methane fermentation is improved.

[0047] Such a foamed resin layer 1103 can be composed of a foamed resin. The foamed resin is not particularly limited, but examples include polyurethane resin, polystyrene resin, polyolefin resin (e.g., polyethylene resin, polypropylene resin), phenolic resin, polyvinyl chloride resin, urea resin, silicone resin, polyimide resin, melamine resin, etc., and one of these can be used alone or in combination of two or more. Among the above, it is preferable that the foamed resin layer 1103 contains polyurethane resin. Polyurethane resin has a composition similar to that of polyurea resin and has excellent affinity and adhesion to the polyurea resin layer 1105.

[0048] Furthermore, the thickness of the foamed resin layer 1103 is not particularly limited, but for example, it is 1.0 mm or more and 100 mm or less, preferably 3.0 mm or more and 50 mm or less. By having the thickness of the foamed resin layer 1103 within the above range, it is possible to sufficiently improve the heat retention of the fermentation tank body 110 while also ensuring sufficient durability of the fermentation tank body 110.

[0049] Furthermore, the materials constituting the base material 1101 that make up various partition members such as wall members 113, ceiling members 115, floor members 117, and opening / closing doors 119 are not particularly limited and include metal materials, resin materials, glass materials, ceramic materials, concrete, wood materials, fiber-reinforced resin materials, and composite materials of one or more of these. One of these can be used alone or in combination of two or more. In addition, the materials constituting multiple partition members may be different from each other or the same. The materials can be changed as appropriate according to the performance required for the part in which the partition member is used.

[0050] The metal materials are not particularly limited, but examples include iron and steel, duralumin, aluminum, aluminum alloys such as Al-Mg alloys and Al-Mg-Si alloys, copper materials such as oxygen-free copper, tough pitch copper, brass, and free-cutting brass, magnesium materials, titanium materials, and nickel alloys. The iron and steel materials are not particularly limited, but examples include carbon steel such as cold-rolled plates, rolled steel for general structural use, carbon steel for machine structural use, and carbon tool steel, stainless steel, alloy tool steel, cemented carbide steel, high-tensile steel and other alloy steels, and cast iron.

[0051] Examples of resin materials include acrylic resin, polyacetal resin, and epoxy resin. Examples of wood-based materials include laminated timber, veneer laminated timber, plywood, oriented strand board, particleboard, and medium-density fiberboard. Examples of fiber-reinforced resin materials include glass fiber reinforced resin materials, carbon fiber reinforced resin materials, cellulose fiber reinforced resin materials, boron fiber reinforced resin materials, aramid fiber reinforced resin materials, Kevlar fiber reinforced resin materials, Dyneema fiber reinforced resin materials, and Zylon fiber reinforced resin materials.

[0052] Among the materials mentioned above, it is preferable that the base material constituting the partition members includes a metal material. Metal materials have excellent workability and excellent physical strength. In dry methane fermentation, the fermentation tank body 110 is required to have sufficient airtightness, pressure resistance, and excellent durability. From this viewpoint, metal materials with excellent workability and physical strength are suitable as materials for constituting the partition members of the fermentation tank body 110.

[0053] Furthermore, among metallic materials, iron and steel, especially carbon steel, are relatively inexpensive and have excellent workability and physical strength (mechanical strength), making them particularly suitable as materials for constituting the partition members of the fermentation tank body 110. Carbon steel, in particular, is inexpensive and has excellent workability and physical strength, but it is a relatively corroded material. However, by coating the parts facing the containment space 111 with the polyurea resin described above, corrosion of the carbon steel can be effectively prevented.

[0054] Furthermore, the materials used for other components constituting the fermentation tank body 110, such as the frame, can be the same as the various materials described for the base material 1101 of the partition member mentioned above.

[0055] The fermentation tank body 110 can be constructed, for example, by arranging the necessary components in a container. Specifically, it can be constructed by using the wall and ceiling components of a container as the base material 1101, placing a foamed resin layer 1103 inside, and then coating it with a polyurea resin to form a polyurea resin layer 1105. Examples of containers include shipping containers and construction containers. Such containers are mass-produced and relatively inexpensive to obtain, and it is easy to select a container with a capacity that matches the planned scale of dry methane fermentation. The fermentation tank body 110 can then be manufactured relatively easily by processing the obtained container, such as by coating it with polyurea resin.

[0056] Furthermore, the capacity of the storage space 111 of the fermentation tank body 110 is not particularly limited, but for example, 10 m³ 3 More than 1,000m 3 Preferably 20m 3 More than 200m 3 Below, more comfortably 30m 3 Over 100m 3 The following is true. Generally, dry methane fermentation tanks tend to have poor heat retention when they are small in size, but despite being relatively small, this fermentation tank body 110 has excellent heat retention thanks to the polyurea resin layer 1105 and foamed resin layer 1103 described above.

[0057] The biogas recovery nozzle 120 is attached to the upper part (ceiling member 115) of the fermentation tank body 110. The biogas recovery nozzle 120 is a nozzle for recovering biogas produced by dry methane fermentation carried out in the dry methane fermentation tank 100. The biogas recovery nozzle 120 is connected to a transfer pipe (not shown), and the biogas recovered from the dry methane fermentation tank 100 via the biogas recovery nozzle 120 is transported through the transfer pipe to the gas storage tank 17, which will be described later.

[0058] The fluid discharge nozzle 130 is attached to the upper part (ceiling member 115) of the fermentation tank body 110.

[0059] The fluid discharge nozzle 130 discharges a fluid, i.e., a composition mainly consisting of gas and / or liquid, towards the containment space 111. Specifically in this embodiment, the fluid discharge nozzle 130 injects the fluid towards the organic resources 200 in the containment space 111. This makes it possible to gently agitate the organic resources 200. The inventors have found that in the dry methane fermentation tank 100 of this embodiment, gentle agitation of the organic resources 200 is possible by fluid discharge from the fluid discharge nozzle 130, even without forcibly performing mechanical agitation with agitators or the like. This is presumed to be because, due to the configuration of the device, there is a large surplus space within the containment space 111 of the fermentation tank body 110 where the organic resources 200 are located, and this allows for the circulation of airflow and liquid through fluid discharge, thereby enabling agitation.

[0060] The fluid discharged from the fluid discharge nozzle 130 can be any fluid, but examples include gases such as air, hydrogen, and carbon dioxide, or liquids such as water and volatile organic acids (acetic acid, propionic acid, butyric acid, isobutyric acid, etc.). Hydrogen, carbon dioxide, and volatile organic acids function as reaction substrates in dry methane fermentation. Therefore, by discharging these reaction substrates from the fluid discharge nozzle 130, it is possible to supply insufficient reaction substrates while stirring the organic resource 200. The fluid may also be a mixture (mixed fluid) containing solids or the like in the above-mentioned fluids. Examples of such mixtures include liquids and / or liquids containing gases or starter cultures derived from processed materials obtained by treating the organic resource 200 before dry methane fermentation. Dry methane fermentation is promoted by adding such a mixture to the organic resource 200.

[0061] The heating device 140 is mounted on the lower part of the inside (containment space 111 side) of the fermentation tank body 110, that is, on the floor member 117, in contact with the containment space 111. In this embodiment, the heating device 140 is arranged along the longitudinal direction of the fermentation tank body 110 while reciprocating in the width direction of the fermentation tank body 110. That is, the heating device 140 is arranged along the longitudinal direction of the fermentation tank body 110 in a meandering manner. The heating device 140 controls the fermentation temperature in dry methane fermentation by heating the organic resources 200 in the fermentation tank body 110.

[0062] Furthermore, the heating device 140 can generate heat by any mechanism, such as an electric heating type (resistance heating type), an electromagnetic heating type such as a microwave heating type, a combustion heating type, a heat pump heating type, etc. Alternatively, the heating device 140 may heat the inside of the fermentation tank body 110 by passing a fluid such as a liquid or gas, used as a heat transfer medium, through a flow path arranged inside the fermentation tank body 110, or it may heat the inside of the fermentation tank body 110 by directly generating heat inside the fermentation tank body 110.

[0063] The dry methane fermentation tank 100 has been described above. Furthermore, the dry methane fermentation tank 100 is equipped with pressure gauges, thermometers, etc., as needed. In addition, each dry methane fermentation tank 100 may be configured to allow the addition of the desired microbial community from the outside.

[0064] The desulfurization apparatus 15 is a device for removing sulfur oxides (SOx) from biogas. The desulfurization apparatus 15 can be any device that can remove sulfur compounds, and can appropriately employ various desulfurization methods such as wet methods employing the lime-gypsum method, magnesium hydroxide method, soda method, etc., dry methods such as activated carbon adsorption method, electron beam method, lime ash utilization method, in-furnace desulfurization method, etc., and semi-dry methods such as spray drying method. The gas storage tank 17 is a pressure-resistant tank for storing biogas that has been desulfurized in the desulfurization unit 15.

[0065] The return culture tank 19 is a tank for producing starter cultures for dry methane fermentation by fermenting a portion of the fermentation residue generated in the dry methane fermentation tank 100.

[0066] The return culture tank 19 is configured to be sealed during fermentation, thereby ensuring an anaerobic environment during fermentation. Furthermore, the return culture tank 19 is equipped with a pressure gauge, a thermometer, and a temperature control device, allowing for temperature control according to the fermentation status. The return culture tank 19 may also be equipped with a stirring device as appropriate to allow for stirring of the fermented material inside the tank. Additionally, the return culture tank 19 may be configured to allow for the addition of desired microbial communities from the outside.

[0067] According to the embodiment described above, in the dry methane fermentation tank 100, at least a portion of the surface of each compartment member constituting the fermentation tank body 110 facing the containment space 111 is covered with a polyurea resin layer 1105. Therefore, even if a wide variety of materials to be fermented (organic resources 200) are introduced into the dry methane fermentation tank 100, and the dry methane fermentation tank 100 is exposed to a wide range of liquid conditions from acidic to alkaline and high temperatures, the fermentation tank body 110 is protected by the chemically stable polyurea resin, and chemical deterioration of the fermentation tank body 110 caused by the fermentation of the materials to be fermented can be suppressed.

[0068] Therefore, even if materials with less-than-ideal chemical durability are used for each component constituting the fermentation tank body 110, such as the partition members, the overall chemical durability of the dry methane fermentation tank 100 can be improved. As a result, the dry methane fermentation tank 100 can be constructed at a relatively low cost.

[0069] Furthermore, polyurea resin has excellent abrasion resistance, and by coating the inner surface of the fermentation tank body 110 with it, damage to the fermentation tank body 110 associated with the input of organic resources 200 and the removal of fermented products can be prevented. In addition, polyurea resin has excellent physical strength, such as high tensile strength, tear strength, and elasticity, and by placing a polyurea resin layer 1105 on the inner surface of the fermentation tank body 110, the physical strength and physical durability of the fermentation tank body 110 itself can be improved.

[0070] As described above, by coating the surface of the partition member of the fermentation tank body 110 facing the accommodation space 111 with a polyurea resin layer 1105, the chemical and physical durability of the fermentation tank body 110 can be improved simultaneously. Therefore, even if the base material of the partition member constituting the fermentation tank body 110 is a relatively inexpensive and less durable material, such as general steel (steel plate), the durability of the fermentation tank body 110, and consequently the dry methane fermentation tank 100, can be improved.

[0071] Furthermore, polyurea resin has a lower thermal conductivity and higher heat insulation properties compared to metal materials and inorganic materials such as concrete. By placing a polyurea resin layer 1105 containing such polyurea resin on the inner surface side of the partition member, heat outflow from the containment space 111 of the fermentation tank body 110 is prevented. As a result, the heat retention of the dry methane fermentation tank 100 can be improved.

[0072] Such a dry methane fermentation tank 100 and dry methane fermentation system 1 can be constructed relatively inexpensively, and are particularly advantageous for constructing relatively small-scale dry methane fermentation systems. In other words, generally, relatively small-scale dry methane fermentation systems have a relatively small amount of organic resources that can be processed, which limits the amount of biogas that can be obtained. As a result, the ratio of the profit obtained from biogas production to the installation cost of the dry methane fermentation system tends to be small. However, the dry methane fermentation tank 100 and dry methane fermentation system 1 can be constructed relatively inexpensively, and because they are small, for example, the dry methane fermentation tank 100 can be manufactured in a factory and transported to the location where the dry methane fermentation tank system 1 will be installed. Furthermore, the dry methane fermentation tank 100 has excellent durability and heat retention, which can reduce maintenance costs during operation and energy consumption during dry methane fermentation. As a result, it is possible to make the above-mentioned profit ratio relatively large. Therefore, while locally produced and consumed dry methane fermentation tends to be relatively small in scale due to its nature, the dry methane fermentation tank 100 and dry methane fermentation system 1 according to this embodiment are suitable for a locally produced and consumed dry methane fermentation system.

[0073] <2. Second Embodiment> Next, a dry methane fermentation system and a dry methane fermentation tank according to a second embodiment of the present invention will be described. The following description will focus on the differences between this system and the first embodiment and its modified examples described above, omitting descriptions of similar configurations. Figure 4 is a diagram of the dry methane fermentation system according to a second embodiment of the present invention, Figure 5 is a schematic cross-sectional view of a dry methane fermentation tank according to a second embodiment of the present invention, and Figure 6 is a schematic cross-sectional view of the fermentation tank body of the dry methane fermentation tank shown in Figure 5, along line xx.

[0074] The dry methane fermentation system 1A according to the second embodiment differs from the dry methane fermentation system 1 according to the first embodiment described above in that, instead of a single dry methane fermentation tank 100, it comprises a group of dry methane fermentation tanks 300 including multiple batch-type dry methane fermentation tanks 100A to 100E. In this way, by comprising a group of multiple batch-type dry methane fermentation tanks 100A to 100E in the dry methane fermentation tanks 100A to 100E, fermentation can be carried out in one batch-type dry methane fermentation tank 100A to 100E without opening or closing the dry methane fermentation tanks 100A to 100E after the material has been added, until the fermentation is completed to the desired stage, thereby suppressing leakage of the generated biogas.

[0075] In other words, for example, after material has been added to dry methane fermentation tank 100A and fermentation has started, if new material to be fermented in the dry methane fermentation tank group 300 becomes available, the material can then be added to dry methane fermentation tank 100B and fermentation can be started. In this way, by sequentially adding material to different dry methane fermentation tanks 100A to 100E and carrying out fermentation, it is possible to complete fermentation in each dry methane fermentation tank 100A to 100E without opening or closing them to the desired stage. The biogas generated in the dry methane fermentation tank group 300 is the target product of the dry methane fermentation system 1, but conventionally, the leakage of biogas due to the addition of material during methane fermentation has been a problem. However, in this embodiment, this problem is prevented by providing multiple dry methane fermentation tanks 100A to 100E.

[0076] The methane-containing gas produced in the dry methane fermentation tank group 300 is transferred as biogas to the gas storage tank 17 via the desulfurization unit 15. In addition, a portion of the fermentation residue after fermentation is transferred to the return bacteria tank 19, and the remainder is used as organic compost 210. In this embodiment, the dry methane fermentation tanks 100A to 100E have the same configuration, so the dry methane fermentation tank 100A will be described as representative below. Also, in Figures 5 and 6, some components have been omitted for the sake of clarity.

[0077] The dry methane fermentation tank 100A is configured to be sealed during fermentation, thereby ensuring an anaerobic environment during fermentation and preventing leakage of generated gases, such as methane. The dry methane fermentation tank 100A comprises a fermentation tank body 110A, a biogas recovery nozzle 120A, a heating device 140A, a biogas circulation unit 150, and a support base 160.

[0078] The fermentation tank body 110A is a cylindrical fermentation tank and has a cylindrical wall member 113A, a floor member 117A, and a lid member 119A, which act as partition members to form a containment space 111A inside. The wall member 113A has a disc-shaped rib 1131 that spreads out around the wall member 113A at its upper end, improving the contact with the lid member 119A and improving the airtightness of the fermentation tank body 110A as a whole. The floor member 117A has an upper floor member 1171A and a lower floor member 1173A located below it, with a space 1175 formed between them. The space 1175 houses the piping 153 of the biogas circulation unit 150, which will be described later, as well as the wiring and equipment of the heater heating device A. The lower floor member 1173A extends outward from the fermentation tank body 110 in a larger circular shape than the wall member 113 in a plan view, contributing to improved installation stability of the fermentation tank body 110A. The lid member 119A is a disc-shaped plate member positioned in close contact with the rib 1131, and is supported by a hinge (not shown) to allow it to be opened and closed.

[0079] The wall member 113A, the upper floor member 1171A, and the lid member 119A are formed by laminating a base material 1101A, a foamed resin layer 1103A, and a polyurea resin layer 1105A in this order from the outside toward the containment space 111A.

[0080] Furthermore, the volume of the fermentation tank body 110A (volume of the containment space 111A) is not particularly limited, but for example, 1.0 m³ 3 Over 500m 3 Preferably 3.0m 3 Over 100m 3 More preferably 5.0m 3 More than 20m 3 The following is true: Despite being relatively small, the fermentation tank body 110A has excellent heat retention thanks to the polyurea resin layer 1105A and the foamed resin layer 1103A mentioned above.

[0081] The heating device 140A is a so-called panel heater and is embedded in the upper floor member 1171A as shown in Figures 5 and 6. Specifically, the heating device 140A is embedded in the foamed resin layer 1103A and its surface is covered with a polyurea resin layer 1105A.

[0082] The biogas circulation unit 150 contributes to the circulation of biogas within the fermentation tank body 110A. The biogas circulation unit 150 comprises a biogas recovery unit 151, piping 153, and a valve 155. The biogas recovery unit 151 is a pipe member inserted into the containment space 111A, penetrating the upper floor member 1171A from the space 1175. As shown in Figure 6, in this embodiment, four biogas recovery units 151 are arranged at the ends of the branched piping 153. The biogas recovery unit 151 has a plurality of holes 1511 along its pipe member, thereby recovering biogas generated in the fermented material 200. The recovered biogas is transported to the biogas recovery nozzle 120A by piping 153 connected to the biogas recovery nozzle 120A. At the biogas recovery nozzle 120A, the transported biogas may be transported outside the fermentation tank body 110A or returned to the containment space 111A. In this way, the biogas circulation unit 150 circulates biogas within the fermentation tank body 110A, removing excess biogas from the fermented material 200 and promoting its fermentation. The operation of the biogas circulation unit 150 can be controlled by opening and closing a valve 155 located in the middle of the piping 153.

[0083] Even in the dry methane fermentation tank 100A described above, the polyurea resin layer 1105A and the foamed resin layer 1103A simultaneously improve the chemical and physical durability of the fermentation tank body 110. Therefore, even if the base material of the partition members constituting the fermentation tank body 110 is a relatively inexpensive and less durable material, such as general steel (steel plate), the durability of the fermentation tank body 110A, and consequently the dry methane fermentation tank 100A, can be improved. In addition, the heat retention of the dry methane fermentation tank 100A is improved.

[0084] <3. Variant> Next, we will describe some modifications of the first embodiment (and the second embodiment) described above. The following description will focus on the differences from the first embodiment (and the second embodiment) described above, and similar configurations will not be described. Note that some components described in the first embodiment described above are omitted in the following drawings for the sake of clarity. Each of the modifications described below may be adopted individually, or multiple modifications may be combined as long as it is technically possible. While the following description will focus on comparing the modifications with the first embodiment, it goes without saying that each of the following modifications can be adopted in the second embodiment.

[0085] In the first embodiment described above, each partition member constituting the fermentation tank body 110 was formed by laminating a base material 1101, a foamed resin layer 1103, and a polyurea resin layer 1105 in that order from the outside toward the containment space 111. However, the present invention is not limited thereto, and as long as a polyurea resin layer is formed on the containment space side of the base material, the partition members can have any layer configuration.

[0086] For example, the wall member 113F, which serves as a partition member as shown in Figure 7, includes a base material 1101F and a polyurea resin layer 1105F covering the side facing the containment space 111F. Even with such a simple layer configuration, the placement of the polyurea resin layer 1105F on the side facing the containment space 111F protects the base material 1101F of the fermentation tank body, thereby improving the durability of the fermentation tank body 110. Furthermore, by placing the polyurea resin layer 1105F, which has relatively low thermal conductivity and high heat insulation properties, on the side facing the containment space 111F of the base material 1101F, heat outflow from within the containment space 111F is suppressed.

[0087] Furthermore, for example, the wall member 113G as a partition member shown in Figure 8 includes a base material 1101G, a polyurea resin layer 1105G covering the side of the containment space 111G, and a foamed resin layer 1103G laminated on the side of the base material 1101G opposite to the polyurea resin layer 1105G. When the foamed resin layer 1103G is placed on the outside side of the partition member in this way, it is possible to prevent the influence of temperature changes in the external environment on the fermentation temperature in the fermentation tank body.

[0088] Alternatively, for example, the wall member 113H as a partition member shown in Figure 9 includes a base material 1101H, a polyurea resin layer 1105H covering the side facing the containment space 111H, a foamed resin layer 1103H positioned between the base material 1101H and the polyurea resin layer 1105H, and a foamed resin layer 1103I laminated on the side of the base material 1101H opposite to the polyurea resin layer 1105H. By arranging the foamed resin layers 1103H and 1103I on both sides of the base material 1101C in this way, the heat retention of the fermentation tank body is further improved.

[0089] Furthermore, in the above-described embodiment, the entire surface of each partition member of the fermentation tank body 110 of the dry methane fermentation tank 100 facing the containment space 111 was covered with the polyurea resin layer 1105. However, the present invention is not limited to this, and it is sufficient if at least a portion of the surface of any of the partition members of the fermentation tank body 110 facing the containment space 111 is covered with the polyurea resin layer 1105.

[0090] For example, the polyurea resin layer 1105 may be formed only on the wall member 113 and the ceiling member 115 of the partition members, while the floor member 117 does not need to be coated with polyurea resin. Alternatively, the polyurea resin layer 1105 may be formed only on the members of the fermentation tank body 110 that have poor durability in dry methane fermentation.

[0091] The area of ​​the polyurea resin layer 1105 formed on the surface of each compartment member facing the accommodation space 111 of the fermentation tank body 110 of the dry methane fermentation tank 100 is not particularly limited, but can be, for example, 30% or more, preferably 50% or more, and more preferably 80% or more. This can further improve the durability and heat retention of the dry methane fermentation tank 100.

[0092] Furthermore, although the above-described embodiments were explained assuming that the heat insulating layer is a foamed resin layer 1103, 1103A, the present invention is not limited thereto, and any heat insulating material can be used as the heat insulating layer. The heat insulating material constituting the heat insulating layer is not particularly limited, and in addition to the material constituting the foamed resin layer 1103 described above, examples include inorganic fiber materials such as glass wool, rock wool, and mineral wool; foamed inorganic materials such as zeolite, silica aerogel, and foamed glass; and organic fiber materials such as cork, cotton, cellulose fibers, sheep's wool, recycled paper fibers, and coconut fibers. One or more of these can be used in combination.

[0093] Furthermore, although the above-described embodiments explained that the dry methane fermentation tank 100 is used in the dry methane fermentation system 1 described above, the present invention is not limited thereto, and the dry methane fermentation tank of the present invention can be used in any dry methane fermentation system or dry methane fermentation method.

[0094] For example, in the embodiment described above, the crushed organic resources 200 were directly subjected to dry methane fermentation in the dry methane fermentation tank 100, but the present invention is not limited thereto. For example, a pretreatment device may be provided so that the crushed organic resources 200 undergo pretreatment before being subjected to dry methane fermentation.

[0095] Examples of such pretreatment devices include drying devices and humidifying devices for adjusting the moisture content of the organic resource 200, crushing devices and explosion devices for further reducing the organic resource 200, and pre-fermentation devices for performing pre-fermentation (e.g., primary fermentation) on the organic resource 200 prior to dry methane fermentation. These can be used individually or in combination of two or more types.

[0096] Although the present invention has been described in detail above based on preferred embodiments, the present invention is not limited thereto, and each component can be replaced with any component that can perform a similar function, or any component can be added. [Explanation of Symbols]

[0097] 1.1A Dry methane fermentation system 11. Crusher 13 Mixing machine 15 Desulfurization equipment 17 Gas storage tank 19. Returning bacteria tank 100, 100A Dry Methane Fermentation Tank 110, 110A Fermentation tank body 1101 Base material 1103 Foamed resin layer (insulating layer) 1105 Polyurea resin layer 111, 111A Containment space 113, 113A Wall members 115 Ceiling components 117, 117A Floor members 119 Opening and closing doors 119A Cover Member 120 Biogas Recovery Nozzles 130 Fluid discharge nozzles 140, 140A heating device 150 Biogas Circulation Unit 160 Support stand

Claims

1. It has a fermentation tank body for carrying out dry methane fermentation by storing organic resources and / or raw materials derived from organic resources in a containment space, The fermentation tank body includes a partition member that separates the containment space from the outside of the fermentation tank body. The partition member comprises a base material and a polyurea resin layer provided on the side of the base material closer to the containment space and having at least a portion of the surface facing the containment space, in a dry methane fermentation tank.

2. The dry methane fermentation tank according to claim 1, wherein the partition member further has an insulating layer.

3. The dry methane fermentation tank according to claim 2, wherein the insulating layer is disposed between the polyurea resin layer and the substrate.

4. The dry methane fermentation tank according to claim 2, wherein the heat insulating layer is a foamed resin layer.

5. The dry methane fermentation tank according to claim 1, wherein the partition member includes a metal material.

6. The dry methane fermentation tank according to claim 1, wherein the partition member includes a steel material.

7. The dry methane fermentation tank according to claim 6, wherein the steel material includes carbon steel.

8. The dry methane fermentation tank according to claim 1, wherein the partition member includes a wall member and a ceiling member, and at least a portion of the surface of the wall member and / or the ceiling member facing the containment space is coated with the polyurea resin layer.

9. The dry methane fermentation tank according to claim 1, wherein the fermentation tank body is constructed using a container.

10. Furthermore, the dry methane fermentation tank according to claim 1, having a fluid discharge nozzle attached to the fermentation tank body for discharging fluid toward the containment space.

11. A dry methane fermentation system comprising a dry methane fermentation tank according to any one of claims 1 to 10.

12. The dry methane fermentation system according to claim 11, comprising a plurality of the dry methane fermentation tanks.

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