Hydrogen supply device for methane gas fermentation tank

Abstract

To provide a hydrogen supply device for a methane gas fermentation tank capable of safely and easily eliminating clogging SOLUTION: In a biomethanation reaction for converting carbon dioxide (CO2) contained in a biogas into methane (CH4) by adding hydrogen into a digestive liquid of a methane fermentation tank, a hydrogen gas feeder 11 is inserted and arranged through an insertion part 7 provided in the methane fermentation tank 1. The hydrogen gas supply device includes a first tube part configured such that a distal end region thereof is positioned in the digestive juice W, and a second tube part disposed in the first tube part so as to be capable of being inserted into and pulled out from the first tube part and having a length capable of protruding from a distal end open region of the first tube part, and the second tube part has a hydrogen gas blowing region communicating with the inside of the tube in a protruding region protruding from the distal end open region of the first tube part.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to an improvement in a hydrogen supply device for a methane gas fermenter. [Background technology]

[0002] Efforts are underway worldwide to achieve carbon neutrality, which means reducing greenhouse gas emissions to zero overall. One such initiative is "biomethanation," which produces methane (CH4) by reacting hydrogen with carbon dioxide (CO2) in biogas, which is produced by fermenting sewage sludge, food waste, etc. Biogas is composed of 60% methane (CH4) and 40% carbon dioxide (CO2). Biomethanation converts the carbon dioxide (CO2) in this biogas into methane (CH4), extracting highly concentrated methane (CH4) that can be used as renewable energy.

[0003] In a biomethanation reaction in which carbon dioxide (CO2) contained in biogas is converted to methane (CH4) by adding (diffusing) hydrogen into a methane gas fermentation tank that ferments combustible gases such as methane (CH4), a device has been proposed for supplying hydrogen to the methane gas fermentation tank, in which a diffuser (diffusing pipe) 50 for adding hydrogen (H2) is immersed and disposed in the digested liquid W in the methane gas fermentation tank 1, as shown in FIG. 12 (see, for example, Patent Document 1).

[0004] Here, when the supply of hydrogen is stopped or when intermittent operation is performed, it is conceivable that the diffuser 50 may become clogged with suspended matter (fine particles) present in the digested liquid W. As shown in Figure 12, in a structure in which the diffuser 50 is simply immersed and disposed in the methane gas fermentation tank 1, if the diffuser 50 becomes clogged, the entire diffuser 50 must be removed from the methane gas fermentation tank 1 to clear the clog.

[0005] However, when removing the diffuser 50 from the methane gas fermentation tank 1, because methane (CH4), a combustible gas, is handled, safety measures such as purging the methane gas fermentation tank 1 with nitrogen are required to remove the diffuser 50 disposed in the methane gas fermentation tank 1. Therefore, there are problems such as the labor and time required for taking such safety measures. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 01-119397 Summary of the Invention [Problem to be solved by the invention]

[0007] The present invention has been made to solve the problems associated with the prior art, and its object is to provide a hydrogen supply device for a methane gas fermenter that can safely and easily eliminate clogging. [Means for solving the problem]

[0008] To achieve this object, the first invention provides a biomethanation reaction in which carbon dioxide contained in biogas is converted into methane by adding hydrogen to a digested liquid in a methane gas fermenter, a first pipe portion of a desired length that is inserted through an insertion portion provided in the methane gas fermenter and configured so that at least a tip region in the insertion direction is positioned in the digested liquid; a second tubular portion that is removably inserted into the first tubular portion and has a length that allows it to protrude a desired length from the distal end open region of the first tubular portion, The second pipe section is a hydrogen supply device for a methane gas fermenter, characterized in that it has a hydrogen gas blowing area communicating with the inside of the pipe in a protruding area protruding from the open area at the tip of the first pipe section.

[0009] The second invention is a hydrogen supply device for a methane gas fermenter according to the first invention, characterized in that the hydrogen gas blowing area is a bubble blowing section consisting of a large number of coarse holes that can diffuse hydrogen gas into the digested liquid as coarse bubbles.

[0010] The third aspect of the present invention is the first aspect of the present invention, wherein the second pipe portion has a divided structure that can be separated and connected to a first constituent pipe to an nth constituent pipe in the length direction, The distal end surface of the first component pipe located at the distal end in the insertion direction has an opening communicating with the interior of the first component pipe, The hydrogen gas blowing area is a bubble blowing section made up of micropores in a polymer separation membrane (membrane filter) arranged in an area a desired distance away from the open end of the first component tube in the direction of the nth component tube, which is a hydrogen supply device for a methane gas fermenter.

[0011] A fourth aspect of the present invention is the methane gas fermenter according to any one of the first to third aspects of the present invention, wherein the methane gas fermenter includes an agitator that generates an upward flow, The hydrogen supply device for a methane gas fermentation tank is characterized in that the insertion portion is drilled at a position where the first pipe portion and the second pipe portion can be arranged near the inner wall surface of the fermentation tank.

[0012] The fifth aspect of the present invention is the hydrogen supply device for a methane gas fermentation tank according to the fourth aspect of the present invention, characterized in that the insertion portions are perforated in a plurality in the circumferential direction on the upper surface of the methane gas fermentation tank. [Effects of the Invention]

[0013] According to the present invention, it is possible to provide a hydrogen supply device for a methane gas fermenter that can safely and easily eliminate clogging. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is a schematic plan view of a methane gas fermenter incorporating a hydrogen supply device according to a first embodiment. FIG. [Figure 2] 1 is a schematic vertical cross-sectional view of a methane gas fermenter incorporating a hydrogen supply device according to a first embodiment. [Figure 3] 1 is a schematic vertical cross-sectional view of the entire hydrogen supply device of a first embodiment. [Figure 4] FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. [Figure 5] 4A is a cross-sectional view taken along line VV in FIG. 3, and FIG. 4B is a partially enlarged cross-sectional view showing an enlarged portion of the vibration suppression structure. [Figure 6] FIG. 10 is a schematic plan view of a methane gas fermenter incorporating a hydrogen supply device according to a second embodiment. [Figure 7] FIG. 10 is a schematic vertical cross-sectional view of a methane gas fermenter incorporating a hydrogen supply device according to a second embodiment. [Figure 8] FIG. 4 is a schematic vertical cross-sectional view of the entire hydrogen supply device of the second embodiment. [Figure 9] (a) is a partially enlarged schematic cross-sectional view showing the state in which the second pipe section is pulled out vertically upward, and (b) is a partially enlarged schematic cross-sectional view showing the state in which the pulled-out second pipe section has been separated and removed. [Figure 10] FIG. 4 is a schematic cross-sectional view showing a partially enlarged open-mouth region of the second pipe portion. [Figure 11] FIG. 10 is a cross-sectional view taken along line XI-XI in FIG. 8. [Figure 12] FIG. 1 is a schematic diagram of a methane gas fermenter incorporating a conventional hydrogen supply device. DETAILED DESCRIPTION OF THE INVENTION

[0015] An embodiment of the present invention will be described below. It should be noted that this embodiment is merely one embodiment of the present invention, and should not be construed as being limited to this embodiment in any way, and appropriate design modifications are possible within the scope of the present invention. "First embodiment"

[0016] Figures 1 to 5 show a first embodiment of a hydrogen supply device for a methane gas fermenter that can safely and easily unclog the hydrogen supply device in a biomethanation reaction in which carbon dioxide (CO2) contained in biogas is converted into methane (CH4) by adding hydrogen gas (H2) to the digested liquid W in the methane gas fermenter 1.

[0017] In the methane gas fermenter 1, biomaterials such as sewage sludge and food waste are fed into the tank, where they are decomposed by anaerobic microorganisms (e.g., methane-producing bacteria) and subjected to methane fermentation to generate biogas containing carbon dioxide (CO2) and methane (CH4). The methane gas (CH4) obtained by fermentation is taken out of the tank via a discharge line connected to the methane gas fermenter 1. The methane gas fermenter 1 envisioned in this embodiment is composed of, for example, a cylindrical tank body 3 with a bottom and an open top in the vertical direction H, and a lid portion 5 that seals the open top area of ​​the tank body 3 (see Figures 1 and 2). The lid portion 5 is provided with a large number of insertion portions 7 into which the hydrogen supply device 11 of this embodiment can be inserted and disposed.

[0018] In this embodiment, a plurality of holes are drilled in the circumferential direction on the upper surface of the lid portion 5 so that the outside of the tank communicates with the internal space of the tank body 3, and these holes function as insertion portions 7.

[0019] The insertion portion (insertion hole) 7 is formed at a position where the hydrogen supply device 11 can be disposed close to the inner wall surface 3a of the tank body 3. In other words, the insertion portion (insertion hole) 7 is formed at a position where the hydrogen supply device 11 can be disposed close to and along the inner wall surface 3a. As shown in FIGS. 1 and 2, in this embodiment, 12 insertion portions 7 are drilled at equal intervals (30 degree intervals) on an imaginary circle (PCD: Pitch Circle Diameter).

[0020] An agitator 9 for agitating the digestion liquid W in the tank is disposed in the central region of the internal space of the tank body 3. In this embodiment, for example, the agitator 9 is configured to generate an upward flow in the digestion liquid W. The agitator 9 is not particularly limited, and any agitator having a known structure can be appropriately selected and adopted within the scope of the present invention, and therefore a detailed description thereof will be omitted here. Furthermore, the agitator 9 is not limited to the structure that generates an upward flow as in this embodiment, but may be a structure that generates a downward flow.

[0021] The methane fermentation tank 1 employed in the present invention is not particularly limited in its interpretation, and the other components are not particularly limited in its interpretation, so detailed explanations are omitted, and the design can be modified as appropriate within the scope of the present invention.

[0022] The hydrogen supply device 11 of this embodiment is composed of a first pipe section (sheath pipe) 13 and a second pipe section (hydrogen gas supply pipe) 21 that is disposed in the first pipe section 13 so as to be insertable and detachable.

[0023] In this embodiment, the first pipe portion 13 is formed of, for example, stainless steel (SUS) as a circular pipe body with a desired outer diameter and desired length and open at both ends. An annular flange portion 17 is integrally provided on the outer periphery of the upper end of the first pipe portion 13 (see FIG. 3). In this embodiment, the annular flange portion 17 is formed separately and is integrally disposed on the outer periphery of the first pipe portion 13 by welding, but it is also possible to adopt a form in which the flange portion 17 is integrally formed on the outer periphery of the first pipe portion 13, and the design can be modified as appropriate.

[0024] The first pipe section 13 has an outer diameter that allows it to be inserted into the insertion section (insertion hole) 7 provided in the lid section 5 in tight sliding contact. The first pipe section 13 is inserted into the insertion section 7 and then placed in concrete (buried). The first pipe section 13 has a length in the pipe insertion direction P such that at least the tip region 15 is positioned in the digested liquid W in the methane gas fermenter 1. In this embodiment, the first pipe section 13 is positioned so that about half of its length is immersed in the digested liquid W (see FIG. 2).

[0025] The second pipe section 21 has a pipe body 23 formed in the shape of a circular pipe that is longer and has a smaller diameter than the first pipe section 13 and is open at both the top and bottom ends, and is disposed so as to be insertable and removable within the first pipe section 13. The second pipe section 21 has an upwardly protruding region 24 that protrudes upward by a predetermined length from the open upper end of the first pipe section 13, and is formed to have an overall length with a downwardly protruding region 23 that protrudes by a desired length from the tip open region 15 of the first pipe section 13 (see FIG. 3). Since the second pipe portion 21 must be pulled out upward in the vertical direction H, it must be as lightweight as possible, and in this embodiment it is assumed to be made of stainless steel (SUS). An annular flange portion 19 is integrally formed on the outer periphery of the upper region 24 of the second pipe portion 21. In this embodiment, the annular flange portion 19 is molded separately and is welded to the outer periphery of the second pipe portion 21, but it is also possible to mold the flange portion 19 integrally with the outer periphery of the second pipe portion 21, and the design can be modified as appropriate. The flange portion 19 is attached and fixed to the flange portion 17 of the first pipe portion 13 by bolting.

[0026] The second pipe section 21 has a downward protruding region 23 protruding from the tip open region 15 of the first pipe section 13, and a hydrogen gas blowing region (bubble blowing region) 29 communicating with the inside of the pipe. In this embodiment, the hydrogen gas blowing area (bubble blowing area) 29 is composed of a plurality of bubble blowing portions (holes) 31. There are six bubble blowout sections (holes) 31 drilled at equal intervals (60° intervals) in the same circumferential direction, and three rows drilled at desired intervals along the length of the pipe, for a total of 18 holes, each with a coarse hole size (for example, about 10φ) (see Figures 3 and 4). The hole shape, hole diameter, number of holes, etc. are not particularly limited and can be freely modified in design.

[0027] A hydrogen gas supply line L1 for supplying hydrogen gas (green gas) to the second pipe section 21 is connected to a branching portion of the upwardly protruding region 24 of the second pipe section 21, which protrudes from the open upper end of the first pipe section 13 in the vertical direction H. An annular flange portion 26 is integrally disposed at the upper end of the upwardly protruding region 24. A disk-shaped lid flange portion 35 is bolted to the upper surface of the annular flange portion 26 to seal the upper end of the second pipe section 21. Reference numeral 37 denotes a ring portion integrally protruding from the lid flange portion 35. The second pipe section 21 is lifted via the ring portion 37 using a winch, hoist, or other hoisting device (for automatic lifting) or a pulley (for manual lifting) and removed from the first pipe section 13 for cleaning, replacement, or other work. The annular flange portion 26 and the lid flange portion 35 described above are merely exemplary embodiments and are not intended to be limiting. For example, although not shown, the upper end of the pipe may be closed with a cap or the like. In this case, it is preferable that the upper surface of the cap has a structure such as a ring portion 37 on which a hook for lifting can be attached. In this embodiment, the second pipe portion 21 is described as a circular pipe with open upper and lower ends, the open upper end of which is sealed by the lid flange portion 35, but the upper end may not be open from the beginning, or may be closed later by welding or the like, and the design can be modified as appropriate depending on the specifications of the implementation of the present invention.

[0028] In this embodiment, a pressure gauge 39 for measuring the pressure value inside the second pipe portion 21 is disposed at the branching portion of the upward protruding region 24 . Whether or not the hydrogen gas blowing area (bubble blowing section 31) 29 has become clogged can be confirmed by checking the reading (PG reading) of the pressure gauge 39, since the pressure inside the pipe changes as the holes become clogged. Furthermore, when all of the bubble blowing sections (holes) 31 become completely clogged, hydrogen gas will blow out from the open port at the tip 33 of the second pipe section 21, and the reading (PG reading) of the pressure gauge 39 will become a constant value. Therefore, it is easy to determine that complete clogging has occurred when the PG reading of the pressure gauge 39 indicates a constant value, and it is also easy to determine when to remove the second pipe section 21 (completely clogged state).

[0029] When hydrogen gas is being supplied into the second pipe section 21, the force of the supply causes the second pipe section 21 to vibrate and shake laterally in the gap between the second pipe section 21 and the inner surface of the first pipe section 13. Therefore, a vibration suppression structure 27 for suppressing vibration of the second pipe portion 21 is provided between the inner surface of the first pipe portion 13 and the outer surface of the second pipe portion 21 .

[0030] In this embodiment, three rectangular flat anti-vibration plates (anti-vibration structures) 27 are provided at equal intervals (120 degree intervals) and integrally protrude from the outer circumferential surface of the pipe body 23 of the second pipe section 21 (see Figure 5(a)). Each vibration suppression plate 27 has a tip end surface in the insertion direction P that is formed with a surface portion that is inclined from the outer surface of the second pipe portion 21 toward the opposite direction from the insertion direction (see FIG. 5(b)). The reason for providing such an inclined surface portion is to reduce resistance when inserting the second pipe portion 21 into the first pipe portion 13.

[0031] According to this embodiment, since the agitator 9 that generates an upward flow is provided, the digested liquid W in the methane gas fermentation tank 1 convects as shown by the arrows in Fig. 2. Therefore, a downward flow is generated near the inner wall surface of the tank body 3 (see Fig. 2). In this embodiment, the hydrogen gas blowing area (bubble blowing section 31) 29 is a blowing hole for supplying hydrogen gas into the digestive liquid W, and is made up of coarse holes to prevent clogging.However, since the first pipe section 13 and the second pipe section 21 that make up the hydrogen supply device 11 are arranged near the inner wall surface of the tank main body 3 (arranged close to and along the inner wall surface), the hydrogen gas bubbles blown into the digestive liquid W from the hydrogen gas blowing area (bubble blowing section 31) 29 of the second pipe section 21 are drawn downward by the downward flow, and are efficiently stirred while being prevented from floating up.

[0032] According to this embodiment, the hydrogen gas blowing area 29 of the second pipe section 21, which supplies hydrogen gas into the digestive liquid W, is a bubble blowing section 31 consisting of coarse holes, so it is thought that clogging occurs less frequently.

[0033] According to this embodiment, the hydrogen supply device 11 installed in the methane gas fermenter 1 has a double-pipe configuration including a first pipe section 13 inserted through the insertion section 7 of the lid 5 of the methane gas fermenter 1 and a second pipe section 21 removably inserted into the first pipe section 13. This configuration allows the second pipe section 21 to be removed with at least the tip region of the first pipe section 13 immersed in (positioned in) the digestive fluid W. Therefore, even if all of the bubble blowing sections 31 in the hydrogen gas blowing region 29 provided in the second pipe section 21 become clogged, the second pipe section 21 can be removed and the clogs easily unclogged (cleaned). Since at least the tip region of the first pipe section 13 is positioned in the digestive fluid W, leakage of methane gas (CH4) from the fermenter 1 to the outside of the tank can be prevented. Therefore, removing the second pipe section 21 of the hydrogen supply device 11 for cleaning or replacement does not require extensive safety measures, such as nitrogen purging, inside the methane gas fermenter 1. Therefore, clogging can be prevented safely and easily. Even if the bubble blowing section 31 becomes clogged, the holes themselves are coarse, so it is possible to unclog the holes by forcefully supplying hydrogen gas. Second Embodiment

[0034] 6 to 11 are schematic diagrams showing a second embodiment of the present invention, and since this embodiment has a technical feature in the shape of the second pipe portion 21, the second pipe portion 21 will be described in detail, and the other configurations and effects, including the first pipe portion 13, are the same as those of the first embodiment. Therefore, the same reference numerals are used for the same parts, and the explanation of the other configurations and effects will refer to the first embodiment.

[0035] In this embodiment, 24 insertion portions 7 are provided on the cover portion 5 at equal intervals (15 degree intervals) on an imaginary circle (PCD: Pitch Circle Diameter). The number of insertion portions 7 to be provided can be changed as appropriate depending on the specifications.

[0036] The second pipe portion 21 has a divided structure that allows it to be separated and connected to a first constituent pipe 25a to a sixth constituent pipe 25f in the length direction (see FIGS. 8 and 9). In this embodiment, the third component pipe 25c and the fourth component pipe 25d, the fourth component pipe 25d and the fifth component pipe 25e, and the fifth component pipe 25e and the sixth component pipe 25f are each configured to be separably connectable via union joints 41 (see Figures 8 and 9). The union joint 41 can be of a known type. Furthermore, the number of divisions of the second pipe section 21 can be arbitrarily changed in design as long as the division configuration allows for separation and connection of the first component pipe 25a to the nth component pipe, and the pipe lengths of each divided component pipe may be equal or different.

[0037] The tip 33 of the first component tube 25a located at the tip in the insertion direction P has an opening communicating with the inside of the first component tube 25a (see FIG. 10). The second component tube 25b, which is located a desired distance away from the open port in the vertical direction H, is configured to have a bubble blowing section (hole) 31 made of a polymer separation membrane (membrane tube section) having a large number of micropores as a hydrogen gas blowing area 29 (see Figure 8).

[0038] The membrane tube portion constituting the second component tube 25b is formed into a tubular shape with bubble blowing portions (holes) 31 made of a polymer separation membrane around the entire circumference. The outer and inner diameters of the tube are the same as those of the other component tubes 25a, etc. Also, the membrane structure of this embodiment can be of a known type.

[0039] The second component pipe (membrane pipe portion) 25b is disposed between the first component pipe 25a and the third component pipe 25c, and the respective connection regions are firmly fastened and connected via a fastening band made of, for example, stainless steel (SUS). The connection form between the second component pipe (membrane pipe portion) 25b and the first component pipe 25a and the third component pipe 25c is not limited to a specific interpretation, and may be any form that allows for tight connection via a unit joint or the like of a desired configuration, and also allows for detachable connection and fixation.

[0040] In this embodiment as well, a pressure gauge 39 for measuring the pressure value inside the second pipe portion 21 is provided. For example, if clogging occurs in the holes of the second component tube 25b, which serves as the membrane tube section, the pressure inside the tube changes, and clogging can be confirmed by checking the reading (PG reading) of the pressure gauge 39. Furthermore, if all of the blow-out holes become completely clogged, hydrogen gas will blow out from the open port at the tip 33 of the second tube section 21, and the reading (PG reading) of the pressure gauge 39 will become a constant value. Therefore, it is easy to know that complete clogging has occurred when the PG reading of the pressure gauge 39 indicates a constant value, and it is also easy to know when to remove the second tube section 21 (when it has reached a completely clogged state).

[0041] According to this embodiment, the hydrogen gas blowing area 29 is a bubble blowing section (holes) 31 made of a polymer separation membrane (membrane tube section) having many micropores, so that the efficiency of dissolving hydrogen gas into the digestive liquid W is high.

[0042] When removing the second pipe section 21 from the first pipe section 13, first, as in the first embodiment, the second pipe section 21, which has been pulled up using a winch or the like, is pulled up in the vertical direction H. Then, the pulled-up sixth component pipe 25f is separated from the union joint 41 connected to the fifth component pipe 25e. Subsequently, the pulling-up and separation work is performed in order from the fifth component pipe 25e of the second pipe section 21 to the third component pipe 25c, the second component pipe 25b, and the first component pipe 25a. This allows the component pipes to be pulled up and separated individually, making the pulling-up work compact and easy. It is also safe because there is no risk of gas leakage.

[0043] The second pipe portion 21 of the first embodiment may have a divided structure that can be separated and connected via a union joint 41, like the second pipe portion 21 of the second embodiment. Instead of the second component tube (membrane tube portion) 25b that serves as the hydrogen gas blowing region in the second embodiment, it is also possible to use a hydrogen blowing region consisting of a plurality of blowing holes similar to the first embodiment. The diameter of the blowing holes can be selected arbitrarily depending on the specifications. [Industrial Applicability]

[0044] The present invention is applicable to a wide range of known methane gas fermenters. [Explanation of symbols]

[0045] 1. Methane gas fermenter 3 Tank body 5 Lid 7 Insertion part (insertion hole) 9 Mixer 11 Hydrogen supply device 13 First tube part (sheath tube) 15 Open tip area 21 Second pipe section (hydrogen gas supply pipe) 25a First component 25b Second component tube (membrane tube section) 25c Third component 25d Fourth Component 25e 5th Composition Section 25f 6th component 27 Anti-vibration structure (anti-vibration part) 29 Hydrogen gas injection area 31 Bubble blowing section 33 Tip 39 Pressure gauge 41 Union fitting H Vertical direction P Insertion direction

Claims

1. In the biomethanation reaction, carbon dioxide contained in biogas is converted into methane by adding hydrogen gas to the digested liquid in the methane gas fermentation tank. a first pipe portion of a desired length that is inserted through an insertion portion provided in the methane gas fermenter and configured so that at least a tip region in the insertion direction is positioned in the digested liquid; a second tubular portion that is removably inserted into the first tubular portion and has a length that allows it to protrude a desired length from the distal end open region of the first tubular portion, A hydrogen supply device for a methane gas fermenter, characterized in that the second pipe section has a hydrogen gas blowing area communicating with the inside of the pipe in a protruding area protruding from the open tip area of ​​the first pipe section.

2. 2. The hydrogen supply device for a methane gas fermenter according to claim 1, wherein the hydrogen gas blowing area is a bubble blowing section consisting of a large number of coarse holes that can diffuse hydrogen gas into the digested liquid as coarse bubbles.

3. the second pipe portion has a divided structure that can be separated and connected to a first constituent pipe to an n-th constituent pipe in the length direction, a tip of the first component pipe located at the tip in the insertion direction has an opening communicating with the inside of the first component pipe; 2. The hydrogen supply device for a methane gas fermenter according to claim 1, wherein the hydrogen gas blowing area is a bubble blowing section consisting of micropores in a polymer separation membrane arranged in an area a desired distance away from the open end of the first component tube in the direction of the nth component tube.

4. The methane fermenter includes an agitator that generates an upward flow, 4. A hydrogen supply device for a methane gas fermenter as described in any one of claims 1 to 3, characterized in that the insertion portion is drilled at a position that allows the first pipe portion and the second pipe portion to be arranged near the inner wall surface of the fermenter.

5. 5. The hydrogen supply device for a methane gas fermenter according to claim 4, wherein a plurality of the insertion portions are drilled in the circumferential direction on the upper surface of the methane fermenter.

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