Methane reduction device

Abstract

To provide a methane reduction device capable of reducing the amount of methane generated from a methane generation source on-site.SOLUTION: A methane reduction device 1 includes a methane sensor 11, a methane reduction unit 12, and an outside air supply path 40. The methane sensor 11 detects the presence or absence of methane in the atmosphere. The methane reduction unit 12 reduces a concentration of methane in the atmosphere. The outside air supply path 40 communicates with the atmosphere and the methane reduction unit 12. When the methane sensor 11 detects methane, the methane reduction device 1 supplies atmospheric air to the methane reduction unit 12 through the outside air supply path 40.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a methane reduction device that reduces the amount of methane generated from farmland, pastures, and the like. [Background technology]

[0002] Methane gas is known as one of the greenhouse gases. Known sources of methane gas include natural sources such as wetland soil and oceans, as well as anthropogenic sources such as paddy field soil and livestock waste. Methane gas is responsible for approximately 23% of the impact of all greenhouse gases on global warming, and is known to have a stronger greenhouse effect than carbon dioxide when compared by weight, despite having a shorter average lifespan than carbon dioxide (approximately 10 years in the atmosphere).

[0003] For this reason, attempts are being made to suppress the generation of methane gas from, for example, paddy field soil, wetland soil, and the like.

[0004] For example, Patent Document 1 discloses a methane gas generation inhibitor consisting of magnesium oxide powder and / or magnesium hydroxide powder. This methane gas generation inhibitor is a powder having a particle size of 0.75 mm or less, and is added to an aqueous mixture of putrefactive organic matter such as wetland soil, paddy field soil, or livestock waste to suppress the generation of methane gas.

[0005] Patent Document 2 discloses a microbial preparation for inhibiting the production of harmful gases, such as methane, nitrogen compounds, and sulfides, which are generated in pastures, fields, rice paddies, lakes, marshes, or aquaculture ponds, and for reducing greenhouse gases on a global scale. This microbial preparation contains microorganisms belonging to the genera Bacillus, Lactobacillus, Strptococcus, Candida, and Pichia. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2010-115572 A [Patent Document 2] JP 2009-201354 A Summary of the Invention [Problem to be solved by the invention]

[0007] Thus, in order to suppress the generation of methane gas from methane sources, it has been proposed to add methane generation inhibitors to the sources. However, no method or device has been proposed for reducing methane generated from paddy fields, wetlands, etc., on-site.

[0008] An object of the present invention is to provide a methane reduction device that can reduce the amount of methane generated from a methane generation source on-site. [Means for solving the problem]

[0009] A methane reduction device according to one aspect of the present invention includes a methane sensor that detects the presence or absence of methane in the atmosphere, a methane reduction unit that reduces the concentration of methane in the atmosphere, and an outside air supply path that communicates with the atmosphere and the methane reduction unit. When the methane sensor detects methane, the methane reduction device supplies the atmosphere to the methane reduction unit through the outside air supply path.

[0010] According to the above configuration, outside air can be supplied to the methane reduction unit at the timing when the methane sensor detects the generation of methane. By using such a methane reduction device at a place where methane is generated, the amount of methane contained in the outside air at that place can be reduced on the spot.

[0011] In the methane reducer according to one aspect of the present invention, the methane reducer may have a catalyst that converts methane into carbon dioxide.

[0012] According to the above configuration, the methane reduction section can easily convert methane into carbon dioxide by the action of the catalyst.

[0013] In a methane reduction device according to one aspect of the present invention, the outside air supply pathway may include a first pathway in which the methane sensor is disposed, a second pathway branching off from the first pathway in which the methane reduction unit is disposed, and a valve disposed at the branching point between the first pathway and the second pathway for opening and closing an inlet to the second pathway, and when the methane sensor detects methane, the valve is opened and outside air is supplied to the second pathway.

[0014] According to the above configuration, by opening the valve when the methane sensor detects the generation of methane, outside air can be instantly supplied to the methane reduction unit. Therefore, air can be supplied to the methane reduction unit at a more appropriate timing depending on the presence or absence of methane in the air supplied to the outside air supply path. Furthermore, by arranging the methane sensor and the methane reduction unit in one outside air supply path, it is possible to realize space saving in the outside air supply path.

[0015] In one aspect of the present invention, the methane reduction apparatus is used on water, and includes a floating body for floating on the water and a driving unit for moving on the water surface. The device may further include:

[0016] According to the above configuration, the methane reduction device can be suitably used on the water surface of, for example, a rice paddy, a pond, etc. Effect of the Invention

[0017] According to one aspect of the present invention, a methane reduction device can reduce the amount of methane generated from a methane generation source on-site. [Brief description of the drawings]

[0018] [Figure 1] 1 is a schematic diagram showing a configuration of a methane reduction device according to one embodiment. FIG. [Diagram 2] 2 is a schematic diagram showing the internal configuration of a main body of the methane reduction device according to the first embodiment. FIG. [Diagram 3] 5 is a flowchart showing a flow of opening and closing control of a valve in an outside air supply path. [Figure 4] FIG. 6 is a schematic diagram showing the internal configuration of a main body of a methane reduction device according to a second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In this embodiment, a methane reduction device 1 that reduces the amount of methane generated from farmland such as rice paddies, pastures, and the like will be described as an example.

[0020] <First embodiment> 1 shows the configuration of a methane reduction device 1 according to one embodiment. The methane reduction device 1 is used on water, such as in rice paddies and ponds, and is configured to be movable on water. The methane reduction device 1 mainly includes a main body 10, a drive unit 20, and a floating body 31.

[0021] The main body 10 and the drive unit 20 are disposed on a floating body 31. The floating body 31 has the property of floating on water. For example, a small boat, a ship, a float, or the like can be used as the floating body 31. As a result, the main body 10, the drive unit 20, and the like of the methane reduction device 1 are floating on the water surface H.

[0022] The main body 10 includes a methane sensor 11, a methane reduction unit 12, a control unit 13, and the like.

[0023] The methane sensor 11 detects the presence or absence of methane in the atmosphere. The methane sensor 11 is, for example, a catalytic combustion type, an oxide semiconductor type, an electrochemical type, or other gas sensor. More specifically, the methane sensor 11 is a catalytic combustion type gas sensor. An example of a catalytic combustion type gas sensor is that described in Patent Document 3 (JP 2017-102132 A).

[0024] The methane sensor 11 detects whether or not methane is contained in the atmosphere. The methane sensor 11 may be capable of measuring the methane concentration in the atmosphere. In this case, the methane sensor 11 determines that methane is contained in the atmosphere when the measured methane concentration is equal to or greater than a predetermined value, and determines that methane is not contained in the atmosphere when the measured methane concentration is less than the predetermined value.

[0025] The methane reduction unit 12 reduces the concentration of methane in the atmosphere. The methane reduction unit 12 has a catalyst 51 that converts methane (CH4) into carbon dioxide (CO2). Examples of the catalyst 51 include precious metal catalysts such as platinum and palladium. More specifically, a catalyst in which platinum is supported on alumina is preferably used as the catalyst 51.

[0026] In the first embodiment, the methane sensor 11 and the methane reduction unit 12 are disposed in the outside air supply path 40. Fig. 2 shows the configuration of the outside air supply path 40 disposed in the main body unit 10 in the methane reduction device 1 according to the first embodiment. In Fig. 2, components other than the outside air supply path 40 disposed in the main body unit 10 are omitted from the illustration.

[0027] The outside air supply path 40 is configured to supply outside air to the methane reduction section 12 when the methane sensor 11 detects methane.

[0028] 2, the outside air supply path 40 has a first path 40a, a second path 40b, a gas inlet 41, a first gas exhaust port 42, a second gas exhaust port 43, a fan 44, and a valve 45. In FIG. 2, the flow of gas (air) passing through the outside air supply path 40 of the methane sensor 11 is indicated by arrows.

[0029] One end of the first path 40a is provided with a gas inlet 41, and the other end of the first path 40a is provided with a first gas outlet 42. A methane sensor 11 and a fan 44 are disposed in the first path 40a.

[0030] In this embodiment, the fan 44 is disposed on a side closer to the gas inlet 41 in the first path 40a (this side is referred to as the upstream side of the gas flow). By operating the fan 44, an air flow is formed in the outside air supply path 40, traveling from the gas inlet 41 to each of the gas exhaust ports 42 and 43.

[0031] The methane sensor 11 is disposed in the first path 40a downstream of the fan 44. The methane sensor 11 detects the presence or absence of methane (CH4) contained in the air flowing through the first path 40a. Information regarding the detection result of methane by the methane sensor 11 is transmitted to the control unit 13.

[0032] In this embodiment, the methane sensor 11 detects the presence or absence of methane generation in the surrounding environment. When the methane reduction device 1 is used in a paddy field, the methane sensor 11 detects the presence or absence of methane generated by methanogenic microorganisms living in soil S present under water W in the paddy field.

[0033] As described above, when the methane reduction device 1 is used in wet soil such as a paddy field or a marsh, the methane sensor 11 detects, for example, the presence or absence of methane generated by methanogenic microorganisms living in the marsh soil. On the other hand, when the methane reduction device 1 is used on a ranch or the like, the methane sensor 11 may detect, for example, the presence or absence of methane generated by livestock.

[0034] The second path 40b is provided so as to branch off from the first path. The second path 40b is provided with the methane reducer 12. A second gas outlet 43 is provided at the downstream end of the second path 40b.

[0035] A valve 45 is disposed at the branch point between the first path 40a and the second path 40b. The valve 45 opens and closes an inlet to the second path 40b. The valve 45 is opened and closed based on a command from the control unit 13. The valve 45 is configured, for example, by a three-way valve and a stop valve.

[0036] In this embodiment, when the methane sensor 11 detects methane, the valve 45 is opened and outside air is supplied to the second path 40b.

[0037] As described above, the methane reducer 12 has the catalyst 51 that converts methane into carbon dioxide. Therefore, methane contained in the outside air that flows into the second path 40b is converted into carbon dioxide by the action of the catalyst 51. As a result, gas containing mainly carbon dioxide (CO2) is discharged from the second gas outlet 43. At this time, gas containing methane (CH4) that is approximately the same as the components of the outside air that flows in from the gas inlet 41 is discharged from the first gas outlet 42 of the first path 40a in which the methane sensor 11 is arranged.

[0038] The control unit 13 is connected to each component part (e.g., the methane sensor 11, the methane reduction unit 12, the drive unit 20, etc.) in the methane reduction device 1 and controls them. The control unit 13 includes a CPU, a memory, a timer, etc.

[0039] For example, the control unit 13 can execute the opening and closing operation of the valve 45 upon receiving information on the presence or absence of methane generation from the methane sensor 11. Furthermore, the control unit 13 can operate the drive unit 20 based on its own judgment or on information transmitted from other devices, and can move the methane reduction device 1 to a predetermined position.

[0040] The drive unit 20 includes a motor 21, a screw 22, a rudder 23, and a rechargeable battery 24 (see FIG. 1). The motor 21 starts and stops operation based on commands from the control unit 13 (more specifically, a drive control circuit in the control unit 13).

[0041] When the motor 21 is operated, the screw 22 rotates and the methane reduction device 1 moves on the water surface. At this time, the rudder 23 operates based on a command from the control unit 13 to determine the direction of travel of the methane reduction device 1. This allows the methane reduction device 1 to move on the water surface.

[0042] The methane reduction device 1 according to this embodiment may be one that moves to a predetermined location by its own initiative (so-called self-propelled type), or one that moves by remote control.

[0043] For example, in the case of a self-propelled methane reduction device 1, the methane reduction device 1 is equipped with a camera (not shown). Information on images captured by the camera is transmitted to the control unit 13. The camera captures an image of the periphery of the device 1 (for example, the periphery of the water surface of a rice paddy or the like) and transmits the result to the control unit 13, whereby the control unit 13 can move the methane reduction device 1 by operating the rudder 23 so as to avoid obstacles (for example, crops such as seedlings or rice) contained in the captured image. This allows the methane reduction device 1 to be moved without damaging crops on the rice paddy or the like.

[0044] Next, a description will be given of an example of the operation of the self-propelled methane reducing apparatus 1. FIG.

[0045] When the methane reduction device 1 is started, the drive unit 20 starts operating, and the methane reduction device 1 moves on the water surface H. In the case of a self-propelled methane reduction device 1, the drive unit 20 moves the methane reduction device 1 while avoiding obstacles based on the photographic information from the camera.

[0046] When the methane reduction device 1 starts moving, the control unit 13 operates the fan 44 (step S11). In this state, the valve 45 is closed (step S21). Therefore, in the outside air supply path 40, outside air is supplied only to the first path 40a.

[0047] The methane sensor 11 disposed in the first path 40a detects the presence or absence of methane contained in the outside air flowing through the first path 40a (step S13). If the methane sensor 11 determines that there is no methane in the outside air (NO in step S13), the valve 45 is maintained in a closed state. Then, the methane reduction device 1 continues to move and detects whether or not methane is contained in the outside air.

[0048] Thereafter, if the methane sensor 11 determines that "methane is present in the outside air" (YES in step S13), the control unit 13 opens the valve 45 (step S14). As a result, the outside air is supplied to a second path 40b branching off from the first path 40a. The outside air that flows into the second path 40b passes through the methane reduction unit 12. At this time, the action of the catalyst 51 in the methane reduction unit 12 converts the methane contained in the outside air into carbon dioxide.

[0049] While the methane sensor 11 determines that "methane is present in the outside air" (YES in step S15), the valve 45 is maintained in the open state. Then, the methane reduction device 1 continues to move and detects whether or not methane is present in the outside air.

[0050] Thereafter, if the methane sensor 11 determines that "there is no methane in the outside air" (NO in step S15), the control unit 13 closes the valve 45 (step S16), thereby stopping the supply of outside air to the second path 40b.

[0051] By opening and closing the valve 45 in the above manner, outside air can be instantly supplied to the methane reduction unit 12 at the timing when the methane sensor 11 detects the generation of methane. Then, the methane contained in the outside air supplied to the methane reduction unit 12 is converted to carbon dioxide by the action of the catalyst 51. By using such a methane reduction device 1 in a place where methane is generated, such as a rice paddy, the amount of methane contained in the outside air at that place can be reduced on the spot.

[0052] (Summary of the first embodiment) The methane reduction device 1 according to this embodiment includes a methane sensor 11, a methane reduction unit 12, and an outside air supply path 40. The methane sensor 11 detects the presence or absence of methane in the atmosphere. The methane reduction unit 12 reduces the concentration of methane in the atmosphere. The outside air supply path 40 is configured to supply outside air to the methane reduction unit 12 when the methane sensor 11 detects methane.

[0053] According to the methane reduction device 1 of this embodiment, outside air can be supplied to the methane reduction unit 12 at the timing when the methane sensor 11 detects the generation of methane. By using such a methane reduction device 1 at a place where methane is generated, the amount of methane contained in the outside air at that place can be reduced on the spot.

[0054] In the methane reducer 1 according to this embodiment, the outside air supply path 40 has a first path 40a in which the methane sensor 11 is disposed, and a second path 40b branching from the first path 40a and in which the methane reducer 12 is disposed. A valve 45 is disposed at the branching point between the first path 40a and the second path 40b. When the methane sensor 11 detects methane, the valve 45 is opened to supply outside air to the second path 40b.

[0055] According to the above configuration, by opening the valve 45 at the timing when the methane sensor 11 detects the generation of methane, outside air can be instantly supplied to the methane reduction section. Therefore, air can be supplied to the methane reduction section 12 at a more appropriate timing depending on the presence or absence of methane in the air supplied to the outside air supply path 40. Furthermore, according to the above configuration, it is possible to reduce the discrepancy between the amount of methane detected by the methane sensor 11 and the amount of methane contained in the outside air supplied to the methane reduction section 12.

[0056] In this embodiment, the methane reduction apparatus 1 that moves while floating on water has been described as an example, but the methane reduction apparatus 1 is not limited to use on water and can also be used on land such as farms, swamps, ranches, etc. When using the methane reduction apparatus 1 on land, the drive unit 20 is provided with a moving means (for example, wheels, etc.) suitable for movement on land.

[0057] As described above, the methane reduction apparatus 1 according to the present embodiment can reduce the amount of methane generated from a methane generation source on-site. Therefore, the methane reduction apparatus 1 can be suitably used as a measure against global warming in agriculture.

[0058] <Second embodiment> Next, a second embodiment of the present invention will be described. In the second embodiment, a configuration will be described in which a methane detection path in which a methane sensor 11 is arranged is provided separately from an outside air supply path in which a methane reducer 12 is arranged. Other configurations can be applied similarly to the first embodiment. Therefore, in the second embodiment, the points different from the first embodiment will be mainly described.

[0059] Fig. 4 shows the configuration inside the main body 10 of the methane reduction device 1 according to the second embodiment. In the second embodiment, an outside air supply path 140 and a methane detection path 150 are provided inside the main body 10. In Fig. 4, components other than the outside air supply path 140 and the methane detection path 150 arranged inside the main body 10 are not shown.

[0060] The outside air supply path 140 is configured to supply outside air to the methane reduction unit 12 when the methane sensor 11 detects methane.

[0061] As shown in Fig. 4, outside air supply path 140 has gas inlet 141, gas outlet 142, fan 144, etc. Also, methane detection path 150 has gas inlet 151, gas outlet 152, fan 154, etc. In Fig. 4, the flow of gas (air) passing through outside air supply path 140 and methane detection path 150 is indicated by arrows.

[0062] The methane reduction unit 12 is disposed in the outside air supply path 140. The methane reduction unit 12 has a catalyst 51. By operating the fan 144, an air flow is formed in the outside air supply path 140 from the gas inlet 141 toward each gas outlet 142. Methane contained in the outside air that has flowed into the outside air supply path 140 is converted to carbon dioxide by the action of the catalyst 51. As a result, gas containing mainly carbon dioxide (CO2) is discharged from the gas outlet 142.

[0063] The methane sensor 11 is disposed in the methane detection path 150. By operating the fan 154, an air flow is formed in the methane detection path 150 from the gas inlet 151 to the gas outlet 152. The methane sensor 11 detects the presence or absence of methane (CH4) contained in the air flowing in the methane detection path 150. Information regarding the detection result of methane by the methane sensor 11 is transmitted to the control unit 13.

[0064] In the methane reduction device 1 of this embodiment, when the device starts moving, the control unit 13 operates the fan 154 in the methane detection path 150, while keeping the fan 144 in the outside air supply path 140 stopped.

[0065] Thereafter, at the timing when the methane sensor 11 detects the generation of methane, the control unit 13 operates the fan 144 in the outside air supply path 140. As a result, when the methane sensor 11 detects methane, outside air is supplied to the methane reduction unit 12 in the outside air supply path 140, and the amount of methane contained in the outside air can be reduced.

[0066] As described above, the methane reduction apparatus 1 according to the present embodiment can reduce the amount of methane generated from a methane generation source on-site. Therefore, the methane reduction apparatus 1 can be suitably used as a measure against global warming in agriculture.

[0067] The embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present invention is indicated by the claims, not by the above description, and is intended to include all modifications within the meaning and scope of the claims. In addition, configurations obtained by combining the configurations of the different embodiments described in this specification are also included in the scope of the present invention. [Explanation of symbols]

[0068] 1: Methane reduction device 10: Main body 11: Methane sensor 12: Methane reduction section 13: Control section 20: Drive unit 31: Floating body section 40: Outside air supply route 40a: First Route 40b: Second Route 44: Fan 45: Valve 51: Catalyst 140: Outside air supply route 150: Methane detection pathway

Claims

1. a methane sensor for detecting the presence or absence of methane in the atmosphere; a methane reduction unit that reduces the concentration of methane in the atmosphere; an outside air supply path communicating with the atmosphere and the methane reduction unit; Equipped with a methane reduction device that supplies the atmospheric air to the methane reduction section through the outside air supply path when the methane sensor detects methane;

2. The methane reducer according to claim 1 , wherein the methane reducer comprises a catalyst that converts methane into carbon dioxide.

3. The outside air supply path is a first path in which the methane sensor is disposed; a second path branching off from the first path and including the methane reduction unit; and a valve disposed at a branch point between the first path and the second path, for opening and closing an inlet to the second path; having When the methane sensor detects methane, the valve is opened to supply outside air to the second path. The methane reduction device of claim 1 .

4. The methane reduction device is for use on water, A floating body for floating on the water; A drive unit for moving on the water surface and Further comprising: A methane reduction device according to any one of claims 1 to 3.

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