JPH0810790A - Device and method for taking out gaseous methane - Google Patents

Abstract

PURPOSE:To always maintain optimum conditions and to accelerate methane fermentation by setting the upper limit and lower limit of liquid in a gaseous methane generating tank and controlling a discharge value so as to open this discharge valve at the upper limit level of the liquid and to close the discharge valve at the lower limit level. CONSTITUTION:This gaseous methane taking out device is provided with a piping for carrying night soil from a flush toilet 1 and is provided with a branch pipe 4 of this piping for carrying the night soil by directing this branch pipe toward the inside of the gaseous methane generating tank 5. The upper limit A and lower limit B of the level of the liquid are set at this tank 5 and sensors for detecting the respective liquid levels are disposed at the tank. The discharge valve 23 is so controlled as to be opened at the upper limit level and to be closed at the lower limit level to maintain the optimum conditions for promoting the methane fermentation for generating the gaseous methane. The upper position in the tank 5 is provided with a pipeline for bleeding the gaseous methane and the lower part of the tank 5 is provided with a reside discharge vale 24 for mixing the treated filth of the night soil in the tank 5 with adsorbents, such as ashes, and taking out the mixture for the purpose of forming a fertilizer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a methane gas extraction device and a methane gas extraction method.

[0002]

2. Description of the Related Art Conventionally, research has been conducted on a methane gas extraction device and a methane gas extraction method. In particular,
In pig farms, as part of the treatment of excrement excreted by pigs, it is stored in a treatment storage tank for excrement, etc., and the raw gas generated there is carried through a long thin tube, etc. It has been used for lighting or for cooking. Also, C
H ₄ methane gas emits a small amount of CO ₂ when used as a methane gas automobile. Therefore, it is necessary to use CH ₄ methane gas in order to prevent global warming. Then, when oxygen O ₂ is combined, it becomes methanol, which can be used as a fuel for a methanol automobile. Further, it can be synthesized into a monomer such as a synthetic resin. In this way, the field of application of methane gas is wide, but the technology for extracting methane gas is sufficient.
It cannot be said that it is being researched, and it has become a subject of future research.

[0003]

DISCLOSURE OF THE INVENTION The present invention sets the upper and lower limits of the liquid level at appropriate positions in the methane gas generation tank, and generates methane gas within the upper and lower limits of the liquid level. A sensor for accelerating methane fermentation is provided, and the discharge valve 23 is opened at the upper limit of the liquid level and the discharge valve 23 is opened at the lower limit of the liquid level in association with the sensor.
The first purpose is to accelerate the methane fermentation so that the can be closed. In addition, the present invention uses the discharge valve 23 that can be automatically opened and closed to set the methane gas generation tank 5
Within the upper and lower limits of the level of the liquid inside, the methane fermentation for methane gas generation can be promoted, and the discharge valve 23 is automatically opened at the upper limit of the liquid level, and the lower limit of the liquid level is reached. The second purpose is to automatically close the discharge valve 23 and promote methane fermentation for methane gas generation. Further, the present invention enables the residue discharge valve 24 to be opened and closed by operating the switch C in order to mix the treated waste of human waste in the methane gas generation tank 5 with an adsorbent such as ash to make it a fertilizer. The second purpose is to mix the treated waste of human waste in the methane gas generation tank with an adsorbent such as ash to make a fertilizer. Further, the present invention carries the excrement from the flush toilet by piping, pour the excrement into the methane gas generation tank through the opening of the pipe that carries the excrement, and set the upper and lower limits of the level of the liquid in the methane gas generation tank. Then, the methane fermentation for methane gas generation can be promoted within the upper and lower limits of the level of the liquid, and the discharge valve 23 is opened at the upper limit of the liquid level to discharge at the lower limit of the liquid level. A third object is to provide an apparatus and method for closing the valve 23 and promoting methane fermentation for generating methane gas to take out methane gas. Further, according to the present invention, the methane gas can be extracted from an appropriate position above the methane gas generation tank 5 through a pipe, and the minus part of the extracted methane gas is used as a heat source to provide the methane gas around the methane gas generation tank 5. The heat source pipe can be heated from the outside, and the heat source in the pipe can heat the periphery of the methane gas generation tank 5, and the hot water around the methane gas generation tank 5 heated there The methane gas generation tank 5 is warmed up so that the waste water in the bath or the hot water from the use of solar heat can be supplied to fill the hot water around the methane gas generation tank 5, and the upper limit of the liquid level in the methane gas generation tank is set. The lower limit is set so that the methane fermentation for methane gas generation can be accelerated within the upper and lower limits of the level of the liquid, An apparatus and method for extracting methane gas by opening the discharge valve 23 at the upper limit of Bell and closing the discharge valve 23 at the lower limit of the liquid level so that optimum conditions for promoting methane fermentation for methane gas generation can be maintained. The fourth purpose is to provide.

[0004]

According to the present invention, an upper limit and a lower limit of a liquid level are set at appropriate positions in a methane gas generation tank, and a methane gas is generated within the upper and lower limits of the liquid level. A discharge valve 23 provided with a sensor for promoting methane fermentation, the discharge valve 23 being capable of opening the discharge valve 23 at the upper limit of the liquid level and closing the discharge valve 23 at the lower limit of the liquid level in association with the sensor. The methane gas extraction device is characterized in that the optimum conditions for promoting methane fermentation for methane gas generation can be maintained, and the present invention also relates to a liquid in a methane gas generation tank. By setting the upper and lower limits of the level so that the methane fermentation for methane gas generation can be promoted within the upper and lower limits of the level of the liquid, the upper limit of the level of the liquid,
The methane gas extraction method is characterized in that the discharge valve 23 is opened and the discharge valve 23 is closed at the lower limit of the liquid level so that optimum conditions for promoting methane fermentation for methane gas generation can be maintained.

[0005]

According to the present invention, the upper and lower limits of the liquid level can be set at appropriate positions in the methane gas generation tank, and methane fermentation for methane gas generation can be promoted within the upper and lower limits of the liquid level. A sensor for opening the discharge valve 23 at the upper limit of the liquid level in relation to the sensor,
The methane gas is characterized in that the exhaust valve 23 is arranged so that the exhaust valve 23 can be closed at the lower limit of the liquid level, and the optimum conditions for promoting methane fermentation for methane gas generation can be maintained. Since it is a take-out device, the upper and lower limits of the liquid level can be set at appropriate positions in the methane gas generation tank so that the methane fermentation can be promoted within the upper and lower limits of the liquid level. The condition can be maintained. Further, the present invention, by setting the upper and lower limits of the level of the liquid in the methane gas generation tank, so as to be able to promote methane fermentation for methane gas generation within the upper and lower limits of the level of the liquid, The discharge valve 23 is opened at the upper limit of the liquid level, and the discharge valve 23 is closed at the lower limit of the liquid level so that the optimum conditions for promoting methane fermentation for methane gas generation can be maintained. Since it is a method for extracting methane gas, the upper and lower limits of the liquid level are set at appropriate positions in the methane gas generation tank so that the methane fermentation can be promoted within the upper limit of the liquid level and the lower eye range. Optimum conditions for fermentation can be maintained, and the discharge valve 23 is opened at the upper limit of the liquid level and the discharge valve 23 is closed at the lower limit of the liquid level to promote methane fermentation for methane gas generation. That.

[0006]

Example 1 In the present invention, a pipe for carrying excrement from the flush toilet 1 is provided, an opening portion of the pipe for carrying the excrement is provided so as to face the inside of the methane gas generation tank 5, and the pipe is placed at an appropriate position in the methane gas generation tank 5. By setting the upper and lower limits of the level of the liquid, and arranging a sensor for promoting methane fermentation for methane gas generation within the upper and lower limits of the level of the liquid, in connection with the sensor, the liquid The drain valve 23 is opened at the upper limit of the level and the drain valve 23 is opened at the lower limit of the liquid level.
The methane gas generation tank 5 is provided with a discharge valve 23 that can be closed to prevent the methane gas from flowing into the sewer to maintain optimum conditions for promoting methane fermentation for methane gas generation.
A discharge valve 22 is provided to allow direct discharge of human waste from the flush toilet 1 to the sewer system in the event of a breakdown of the discharge valve 23.
To automatically open the discharge valve 23 and automatically close the discharge valve 23 at the lower limit of the liquid level so that it can be automatically opened and closed to maintain the optimum conditions for promoting methane fermentation for methane gas generation, A pipe line for extracting methane gas is provided at an appropriate position above the methane gas generation tank 5, and sewerage is used to mix the treated waste of human waste in the methane gas generation tank 5 with an adsorbent such as ash to make fertilizer. The switch C that can be taken out without flowing it to the residue discharge valve 24
Water discharge valve 2 that can be installed in the water and discharges water toward the sewer
3 is a methane gas take-out device in which water can be discharged toward the sewer through the water discharge valve 23.

[0007]

[Embodiment 2] In the present invention, the excrement from the flush toilet 1 is carried by a pipe, and the excrement is poured into the methane gas generation tank through the opening of the pipe for carrying the excrement, and the upper limit of the liquid level in the methane gas generation tank And the lower limit are set so that methane fermentation for methane gas generation can be promoted within the upper and lower limits of the level of the liquid, and the discharge valve 23 is opened at the upper limit of the liquid level to set the liquid level. The exhaust valve 23 is closed at the lower limit of the above so that optimum conditions for promoting methane fermentation for methane gas generation can be maintained, and when the methane gas generation tank 5 breaks down, the human waste from the flush toilet 1 is The methane gas generation tank 5 is allowed to flow directly to the sewer through the discharge valve 22 without being made to flow into the methane gas generation tank 5, and the discharge valve 23 can be automatically opened and closed. Accordingly, at the upper level of the liquid, automatically open the discharge valve 23, discharge valve at the lower level of the liquid 23
In order to maintain the optimum conditions for accelerating methane fermentation for methane gas generation and to mix the treated waste of human waste in the methane gas generation tank 5 with an adsorbent such as ash to make fertilizer. The switch C is operated so that the residue discharge valve 24 can be opened and closed, and the treated waste in the methane gas generation tank can be mixed with an adsorbent such as ash to form a fertilizer, which can be taken out without flowing into the sewer. So that the methane gas can be extracted from an appropriate position above the methane gas generation tank 5 through a pipe line.
In order to mix the treated waste of human waste in the methane gas generation tank 5 with an adsorbent such as ash to make fertilizer, the switch C is operated so that the residue discharge valve 24 can be opened and closed. The treated sewage of human waste and an adsorbent such as ash can be mixed to be fertilizer so that it can be taken out without flowing into the sewer, and water can be discharged to the sewer through the water discharge valve 23. A tube for a heat source provided around the methane gas generation tank 5 so that the methane gas can be extracted from an appropriate position above the methane gas generation tank 5 through a pipeline, and a part of the extracted methane gas is used as a heat source. The passage can be heated from the outside, and the periphery of the methane gas generation tank 5 can be warmed by the heat source in the pipe so that the circumference of the methane gas generation tank 5 is heated. The warm water of the methane gas generation tank 5 is warmed by the hot water, and waste water in the bath or hot water using solar heat can be supplied to fill the hot water around the methane gas generation tank 5. The upper limit and the lower limit of the level are set so that the methane fermentation for methane gas generation can be promoted within the range of the upper limit and the lower limit of the liquid level, and the discharge valve 23 is opened at the upper limit of the liquid level, The methane gas extraction method is characterized in that the discharge valve 23 is closed at the lower limit of the liquid level so that the optimum condition for promoting methane fermentation for methane gas generation can be maintained.

[0008]

[Embodiment 3] A drain pipe is connected to a flush toilet 1 including a water-saving toilet, an auxiliary tank 2 is interposed at an intermediate position of the drain pipe, and a storage pipe 3 is provided below the auxiliary tank 2. , A methane gas generation tank 5 at the lower end position of the storage pipe 3.
When the urine breaks down, the human waste from the flush toilet 1 is directly
A discharge valve 22 for flowing into the sewer is provided, and the auxiliary tank 2 is caused to flow down the sewage from the flush toilet 1 together with the wash water flowing out of the flush toilet 1, and the excess portion of the supernatant water is passed through the passage 20. Through the passage 20 to the vertical pipe 19 connected to the passage 20, the lower end of the vertical pipe 19 is connected to the sewer pipe, and the upper end of the vertical pipe 19 is opened. Is provided with a ventilator 27 so that the methane gas can be extracted from an appropriate position above the methane gas generation tank 5 through the pipe line 6, and a part of the extracted methane gas is burned through the pipe line. Two
5, the burner 25 is used as a heat source to heat the waste water of the bath provided around the methane gas generation tank 5 or the hot water supply pipe for supplying heat water from the outside to warm it from the outside. The methane gas generation tank 5 can be heated by the heat source in the pipe, and the methane gas generation tank 5 can be heated by the hot water around the methane gas generation tank 5 which is heated there.
In order to heat the hot water and to fill the hot water around the methane gas generation tank 5, practically all or most of the hot water can be supplied with waste water from the bath or hot water using solar heat, By setting the upper and lower limits of the liquid level in the methane gas generation tank so that methane fermentation for methane gas generation can be promoted within the upper and lower limits of the liquid level, The discharge valve 23 is automatically opened, and the discharge valve 23 can be automatically closed at the lower limit of the liquid level so that optimum conditions for promoting methane fermentation for methane gas generation can be maintained. Is a method for extracting methane gas.

[0009]

[Effect] According to the present invention, the upper limit and the lower limit of the liquid level can be set at appropriate positions in the methane gas generation tank, and the methane fermentation for generating methane gas can be promoted within the upper limit and the lower limit of the liquid level. A sensor for opening the discharge valve 23 at the upper limit of the liquid level in relation to the sensor,
The methane gas is characterized in that the exhaust valve 23 is arranged so that the exhaust valve 23 can be closed at the lower limit of the liquid level, and the optimum conditions for promoting methane fermentation for methane gas generation can be maintained. Since it is a take-out device, the upper and lower limits of the liquid level are set in the methane gas generation tank so that the methane fermentation can be promoted within the upper and lower limits of the liquid level to maintain the optimum conditions for methane fermentation. There are possible effects. Further, the present invention, by setting the upper and lower limits of the level of the liquid in the methane gas generation tank, so as to be able to promote methane fermentation for methane gas generation within the upper and lower limits of the level of the liquid, The drain valve 23 is opened at the upper limit of the liquid level, and the drain valve 23 is opened at the lower limit of the liquid level.
The methane gas extraction method is characterized in that the optimum conditions for accelerating methane fermentation for methane gas generation can be maintained, so the upper limit of the liquid level is set at an appropriate position in the methane gas generation tank. The lower limit can be set so that the methane fermentation can be promoted within the upper and lower limits of the level of the liquid, and the optimum condition of the methane fermentation can be maintained. Opening and closing the discharge valve 23 at the lower limit of the liquid level has the effect of promoting methane fermentation for methane gas generation.

[Brief description of drawings]

FIG. 1 is a system diagram showing a methane gas extraction device according to the present invention.

[Explanation of symbols] 1 flush toilet 2 auxiliary tank communicating with flush toilet 3 storage pipe below auxiliary tank 4 branch pipe to methane gas generation tank 5 methane gas generation tank 6 pipeline from above gas generation tank 7 Discharge pipe from gas generation tank 8 Bath wastewater, heating part using solar heat 9 Stirring blade of methane gas generation tank 10 Deodorizer 11 Compressor 12 Methane gas cylinder 13 Open / close valve 14 Pressure inlet at one end of methane gas cylinder 15 Pressure at the other end of gas cylinder Inlet 16 Detachable detachable valve 17 Compressor driving motor 18 Cylinder piston of switch mechanism 19 Vertical pipe 20 Outflow passage of excess supernatant water 21 Outflow passage from heating section to vertical pipe 22 Discharge valve for flowing into sewer 23 Moisture discharge valve that opens and closes automatically 24 Residue discharge valve 25 Burner 26 Power box and ABC switch 27 Ventilator A liquid level upper limit B liquid level lower limit C Residue discharge valve residue removal switch

Claims (14)

[Claims] 1. A method for promoting methane fermentation for methane gas generation by setting upper and lower limits of a liquid level at appropriate positions in a methane gas generation tank within the upper and lower limits of the liquid level. A discharge valve 2 in which a sensor is provided, and the discharge valve 23 can be opened at the upper limit of the liquid level and the discharge valve 23 can be closed at the lower limit of the liquid level in association with the sensor.
3. A methane gas take-out device, characterized in that 3 is provided so that optimum conditions for promoting methane fermentation for methane gas generation can be maintained. 2. A liquid in a methane gas generation tank, wherein the upper and lower limits of the liquid level are set so that methane fermentation for methane gas generation can be promoted within the upper and lower limits of the liquid level. The discharge valve 23 is opened at the upper limit of the level and the discharge valve 23 is closed at the lower limit of the liquid level so that the optimum condition for promoting methane fermentation for methane gas generation can be maintained. The method for extracting methane gas according to claim 1. 3. A pipe for carrying human waste from the flush toilet is provided, an opening portion of the pipe for carrying human waste is provided toward the methane gas generation tank, and the upper and lower limits of the liquid level are set at appropriate positions in the methane gas generation tank. Is set, and a sensor for accelerating methane fermentation for methane gas generation is arranged within the upper and lower limits of the level of the liquid, and in connection with the sensor, the discharge is performed at the upper limit of the level of the liquid. Discharge valve 23 that opens the valve 23 and closes the discharge valve 23 at the lower limit of the liquid level
The methane gas extraction device according to claim 1, wherein the methane gas extraction device is provided to maintain optimum conditions for promoting methane fermentation for methane gas generation. 4. The excrement from the flush toilet is carried by a pipe, and the excrement is poured into the methane gas generation tank through the opening of the pipe for conveying the excrement, and the upper and lower limits of the liquid level in the methane gas generation tank are set. Then, the methane fermentation for methane gas generation can be promoted within the upper and lower limits of the liquid level, the discharge valve 23 is opened at the upper limit of the liquid level, and the discharge valve 23 is opened at the lower limit of the liquid level. Close 23,
The method for extracting methane gas according to claim 1, wherein the optimum conditions for promoting methane fermentation for generating methane gas can be maintained. 5. A pipe for carrying human waste from the flush toilet is provided, and an opening portion of the pipe carrying human waste is provided at a methane gas generation tank 5
The upper limit and the lower limit of the liquid level are set at appropriate positions in the methane gas generation tank 5, and the methane fermentation for generating methane gas is promoted within the upper limit and the lower limit of the liquid level. For discharging the water by opening the drain valve 23 at the upper limit of the liquid level and closing the drain valve 23 at the lower limit of the liquid level in association with the sensor. A discharge valve 23 capable of shutting off the exhaust gas is provided to maintain the optimum conditions for promoting methane fermentation for methane gas generation, and the treated waste of human waste in the methane gas generation tank 5 is used as an adsorbent such as ash. The residue discharge valve 24 is provided separately from the discharge valve 23 for mixing into fertilizer, and the residue discharge valve 24 is provided with a switch C so that the residue can be taken out without flowing into the sewer.
The methane gas extraction device described. 6. The sewage from the flush toilet is carried by a pipe, and the sewage is poured into the methane gas generation tank through an opening of the pipe for carrying the sewage, and the upper and lower limits of the liquid level in the methane gas generation tank are set. Then, the methane fermentation for methane gas generation can be promoted within the upper and lower limits of the liquid level, the discharge valve 23 is opened at the upper limit of the liquid level, and the discharge valve 23 is opened at the lower limit of the liquid level. Close 23,
In order to maintain optimum conditions for promoting methane fermentation for methane gas generation, and to mix treated waste of human waste in the methane gas generation tank 5 with an adsorbent such as ash to make fertilizer. , The switch C is operated so that the residue discharge valve 24 can be opened and closed, and the treated waste in the methane gas generation tank can be mixed with an adsorbent such as ash to form a fertilizer, without flowing into the sewer. The method for extracting methane gas according to claim 1, wherein a fertilizer produced by mixing the treated waste of human waste and an adsorbent such as ash can be taken out from the branch passage. 7. A pipe for carrying human waste from the flush toilet 1 is provided,
The opening part of the pipe for carrying the human waste is provided toward the methane gas generation tank 5, the upper and lower limits of the liquid level are set at appropriate positions in the methane gas generation tank 5, and the upper and lower limits of the liquid level are set. A sensor for accelerating methane fermentation for the production of methane gas is provided within the range, and in connection with that sensor, at the upper limit of the liquid level, the discharge valve 23
Is installed and the discharge valve 23 is closed at the lower limit of the liquid level so that the discharge valve 23 can be prevented from flowing into the sewer, and the optimum conditions for promoting methane fermentation for methane gas generation are maintained. The methane gas take-out device according to claim 1, further comprising a discharge valve 22 for directing human waste from the flush toilet 1 directly into the sewer when the generation tank 5 fails. 8. The human waste from the flush toilet 1 is carried by piping,
Pour the excrement into the methane gas generation tank through the opening of the pipe that carries the excrement, set the upper and lower limits of the level of the liquid in the methane gas generation tank, and set the upper and lower limits of the level of the liquid to the methane gas level. In order to promote methane fermentation for generation, in order to promote methane fermentation for generation of methane gas, the discharge valve 23 is opened at the upper limit of the liquid level and the discharge valve 23 is closed at the lower limit of the liquid level. The sewage from the flush toilet 1 is not directly caused to flow into the methane gas generation tank 5 when the methane gas generation tank 5 fails, and the sewage is directly supplied to the sewage system. The method for extracting methane gas according to claim 1, wherein 9. An upper limit and a lower limit of the level of the liquid in the methane gas generation tank 5 are set so that methane fermentation for generating methane gas can be promoted within the upper limit and the lower limit of the level of the liquid, The discharge valve 23 is automatically opened at the upper limit of the liquid level, and the discharge valve 23 is automatically closed at the lower limit of the liquid level, and is automatically opened and closed to maintain the optimum conditions for promoting methane fermentation for methane gas generation. Discharge valve 23
The residue discharge valve 24 is provided with a switch C that allows the treated waste of human waste in the methane gas generation tank 5 to be mixed with an adsorbent such as ash and used as fertilizer without being discharged to the sewer. The methane gas extraction device according to claim 1. 10. A discharge valve 23 capable of automatic opening and closing,
The discharge valve 23 is automatically opened at the upper limit of the liquid level so that the methane fermentation for generating methane gas can be promoted within the set upper and lower limits of the liquid level in the methane gas generation tank 5. , Drain valve 23 at the lower limit of the liquid level
In order to maintain the optimum conditions for accelerating methane fermentation for methane gas generation and to mix the treated waste of human waste in the methane gas generation tank 5 with an adsorbent such as ash to make fertilizer. The switch C is operated so that the residue discharge valve 24 can be opened and closed, and the treated waste in the methane gas generation tank can be mixed with an adsorbent such as ash to form a fertilizer, which can be taken out without flowing into the sewer. The method for extracting methane gas according to claim 1, wherein the method is for obtaining. 11. A fertilizer which is provided with a pipe line for extracting methane gas at an appropriate position above the methane gas generation tank 5 and which mixes treated waste of human waste in the methane gas generation tank 5 with an adsorbent such as ash. In order to achieve this, the residue discharge valve 24 is provided with a switch C that can be taken out without flowing into the sewer, and a water discharge valve 23 that can discharge water toward the sewer
The methane gas extraction device according to claim 1, wherein the methane gas extraction device is provided so that the water can be discharged toward the sewer through the water discharge valve 23. 12. A methane gas can be extracted from an appropriate position above the methane gas generation tank 5 through a pipeline, and the treated waste of human waste in the methane gas generation tank 5 is mixed with an adsorbent such as ash. Switch C to actuate the residue discharge valve 24 so that it can be opened and closed,
The treated waste of human waste in the methane gas generation tank and an adsorbent such as ash can be mixed into fertilizer so that it can be taken out without flowing into the sewer. Claim 1 adapted to be discharged
The methane gas extraction method described. 13. A pipe line for extracting methane gas is provided at an appropriate position above the methane gas generation tank 5, and a heat source for warming the methane gas generation tank 5 is provided around the methane gas generation tank 5, and the methane gas is provided. An upper limit and a lower limit of the liquid level are set at appropriate positions in the generation tank 5, and a sensor for accelerating methane fermentation for methane gas generation is provided within the upper limit and the lower limit of the liquid level. In connection with the sensor, the discharge valve 23 is opened at the upper limit of the liquid level and the discharge valve 23 is closed at the lower limit of the liquid level. The methane gas extraction device according to claim 1, wherein the optimum condition for promotion is maintained. 14. A methane gas can be extracted from an appropriate position above the methane gas generation tank 5 through a pipe, and a part of the extracted methane gas is used as a heat source to be provided around the methane gas generation tank 5. A pipe for a heat source can be warmed from the outside, and a heat source in the pipe can warm the periphery of the methane gas generation tank 5, and the hot water around the methane gas generation tank 5 heated there causes the methane gas to be heated. The generation tank 5 is warmed, waste water in the bath or hot water from the use of solar heat to supply hot water around the methane gas generation tank 5, and the upper and lower limits of the liquid level in the methane gas generation tank are supplied. Is set so that methane fermentation for methane gas generation can be promoted within the upper and lower limits of the liquid level, and Open the discharge valve 23 at the upper limit of the Le,
The method for extracting methane gas according to claim 1, wherein the discharge valve 23 is closed at the lower limit of the liquid level so that the optimum condition for promoting methane fermentation for methane gas generation can be maintained.