JP2005246133A - Methane fermentation apparatus and methane fermentation method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To realize a stirring apparatus constituted of a methane fermentation tank which has good conveyance volume efficiency and realizes sufficient stirring. <P>SOLUTION: A methane fermentation apparatus is provided with: the box type methane fermentation tank in which organic waste is charged and then microorganisms are added to cause methane fermentation; a stirrer which moves repetitively and vertically inside the box type methane fermentation tank; and a driving device for moving the stirrer repetitively and vertically. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

The present invention relates to a methane fermentation apparatus comprising a box-type methane fermentation tank for methane fermentation of organic waste such as livestock waste and garbage.

In the case of a methane fermentation apparatus that decomposes organic waste and produces biogas by fermentation action of methane fermentation in a methane fermentation tank, this biogas can be used effectively as a fuel for a cogeneration system. .
For example, as a method of treating organic waste, the waste is crushed, and the crushed matter is biologically treated by anaerobic microorganisms in an anaerobic treatment tank in which anaerobic microorganisms such as methane bacteria float. An anaerobic digestion treatment method is disclosed in which digestion gas containing methane as a main component is generated and the digestion gas is effectively used as fuel (Japanese Patent Laid-Open Nos. 11-28445 and 11-300433). No. publication).
In recent years, methane fermentation has attracted attention as one of organic waste treatment methods and has begun to spread.
In this methane fermentation method, when high-molecular organic substances contained in wastewater and waste are decomposed to methane, 1) low molecular weight by hydrolyzing bacteria 2) production of organic acids by acid-fermenting bacteria 3) methane by methane bacteria It progresses at the same time in three steps of generation, and as a whole, dozens of kinds of microorganisms work. Therefore, in order to perform methane fermentation efficiently, it is very important to continue to provide a suitable environment for methane fermentation. This is because the organic waste in the methane fermentation tank is stirred and maintained at a constant temperature, thereby effectively promoting the fermentation action of the methane fermentation bacteria and efficiently producing biogas. It is.
In other words, in order to efficiently perform methane fermentation in a methane fermentation tank, it is important to sufficiently stir organic waste such as livestock waste and garbage and microorganisms so that they have an even and official fermentation temperature. It becomes.
Conventional stirring techniques include: (1) a type in which a vertical cylindrical methane fermenter is used to stir with a propeller, and (2) a horizontal cylindrical methane fermenter in which a stirring tool comprising a heating tube is used. There was a type of rotating and stirring.
As a conventional stirring technique, the reason for not using a rotating stirring tool such as a propeller blade in the box-type methane fermentation tank is that the central part of the box-type methane fermentation around the rotating stirring tool can be sufficiently stirred. However, in the vicinity of the inner wall of the methane fermentation, there is a region where the rotating stirrer does not reach, where stirring is insufficient and methane fermentation cannot be performed efficiently. In order to avoid a region where the rotating stirring tool does not reach, a rotating type stirring tool that is stirred with a propeller has been used in the cylindrical methane fermenter.
However, when the cylindrical methane fermenter is transported by a transport vehicle such as a trailer, the transport volume efficiency of the methane fermenter is reduced as compared with the box-type methane fermenter.
However, since the stirring method of the box-type methane fermentation tank has not been solved, the box-type methane fermentation tank itself has not been realized.
Moreover, the subject of the realization technique of the heating method of a box-type methane fermenter was unsolved.
Furthermore, after preheating the organic waste such as livestock waste and garbage with a preheating device installed outside the methane fermentation tank, the organic waste is put into the methane fermentation tank.
After the organic waste is put into the methane fermenter, the preheating device is exposed to the outside air in winter, and the temperature of the preheating device rapidly decreases.
When the organic waste is again put into the methane fermentation tank, it is necessary to reheat the preheating device cooled by the outside air and lowered in temperature, and the energy consumed for heating the preheating device is discarded to the outside air. Therefore, the preheating efficiency of the methane fermentation apparatus is poor, and it is necessary to further improve energy saving.

JP-A-11-28445 JP 11-300323 A

From the above, the problem to be solved by the present invention is to realize an agitation apparatus comprising a methane fermentation tank that has good transport volume efficiency and can be sufficiently agitated.
Furthermore, the problem to be solved by the invention is to realize an agitator comprising a methane fermentation tank that has good transport volume efficiency and can be easily heated.
Furthermore, the problem to be solved by the invention is to realize a stirring device comprising a methane fermenter that increases the preheating efficiency of the organic waste and further improves energy saving.

Hereinafter, the terminology will be explained below in order to eliminate doubts about the interpretation of terms used in the claims and the specification of the present application.
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<Explanation of terms>
O A methane fermentation apparatus means the methane fermentation apparatus which decomposes | disassembles organic waste and produces | generates biogas by methane fermentation.
The methane fermentation apparatus is classified into a household methane fermentation apparatus and a commercial methane fermentation apparatus according to usage. In the present invention, when the home methane fermentation apparatus is symmetric, the methane fermentation apparatus is to be read as a household methane fermentation apparatus. In the present invention, when the commercial methane fermentation apparatus is symmetric, the methane fermentation apparatus is to be read as the commercial methane fermentation apparatus.
In the present invention, the commercial methane fermentation apparatus will be mainly described. However, the methane fermentation apparatus of the present invention is not necessarily limited to the commercial methane fermentation apparatus.
O Organic waste refers to animal waste or food waste.
The organic waste is a slurry-like mixture (also referred to as organic slurry) obtained by mixing solid organic waste and liquid organic waste (also referred to as organic wastewater) and crushing the mixture with a crusher. Say. In addition, the above is an illustration, Comprising: It is not necessarily limited to this.
O Inputting organic waste means, for example, bringing organic waste (slurry mixture obtained by crushing the mixture with a crusher) into the methane fermentation tank through the organic waste input pipe.
It is not necessarily limited to the above, and it is also conceivable to drop solid organic waste into the methane fermentation tank from the opening.
O The methane fermentation method refers to the production of methane by decomposing organic waste into methane fermentation microorganisms. More specifically, after organic waste (a mixture of solid and organic wastewater) is pulverized and slurried, this slurry is put into a fermenter and fermented with methane-fermenting bacteria under anaerobic conditions. This is a method of decomposing the organic waste into biogas and water, and has the merit that the organic waste can be greatly reduced and the biogas produced as a by-product can be recovered as energy. In addition, since it is anaerobic and does not require aeration power, it is an energy-saving treatment method.
Methane fermentation is a process of converting organic substrates into biogas through joint work by a plurality of different microorganism groups (hereinafter sometimes referred to as methane fermentation microorganism groups). Various organic wastewater and garbage are used as materials. It can be.
It is held in a methane fermentation tank at a predetermined fermentation temperature suitable for growth of methane fermentation bacteria and the like (37 ° C for low-temperature methane fermentation and 55 ° C for high-temperature methane fermentation is a suitable temperature for methane fermentation). Thus, the maximum reaction rate of methane fermentation can be obtained under a suitable environment.
○ Biogas is a gas obtained by methane fermentation of organic waste such as livestock manure and garbage. It mainly consists of methane (CH4: approx. 60%) and carbon dioxide (CO2: approx. 40%). ing. Various organic wastes can be used as raw materials (livestock manure, food waste from household / food industry, organic residues from food industry, sewage sludge, etc.), but the livestock excrement law was enforced in November 1999 (provisional measures) 5 years) has attracted attention as one of the effective methods for utilizing livestock manure.

The fermented digestive juice that has generated biogas by anaerobic fermentation can be used as liquid fertilizer or compost because the fertilizer component remains.
* A box-type methane fermenter means a box-type methane fermenter. The biggest feature of the box-type methane fermenter is that the box-type methane fermenter can be loaded and transported on a trailer or the like, as in container transportation, so that the transport capacity efficiency is large.
The outer dimensions of the box-type methane fermenter are, for example, 20 ft and 40 ft general container sizes because the box methane fermenter is to be transported.
The former has a length (outer dimension) of 19′-10 ″ 1/2 (6,058 mm), a width (outer dimension) of 8 ′ (2,438 mm), and a height (outer dimension) of 8′-06 ″. The size is (2,591 mm).
The latter has a length (outer dimension) of 40 ′ (12,192 mm), a width (outer dimension) of 8 ′ (2,438 mm), and a height (outer dimension) of 8′-06 ″ (2,591 mm). It is a size.
* A cylindrical methane fermenter means a cylindrical methane fermenter. The conventional methane fermenter was a cylindrical methane fermenter. There are two types of cylindrical methane fermenters: vertical and horizontal. Each is characterized by rotating by rotating a stirring unit such as a propeller. As a prior art, there was no methane fermenter of any type other than the cylindrical methane fermenter. The prejudice that a cylindrical shape was necessary for stirring to rotate the stirring tool was in the minds of those skilled in the art. It was big.
O A vertical cylindrical methane fermenter is a methane fermenter in which the longitudinal direction of the cylindrical methane fermenter is a vertical direction, and is long and thin and has a cylindrical cross section.
O A horizontal cylindrical methane fermenter is a methane fermenter with a cylindrical methane fermenter having a horizontal direction in the longitudinal direction and lying horizontally and having a cylindrical cross section.
〇Transportation volume efficiency refers to the ratio of volume per transportation (m ³ / time). Since the transport volume efficiency of the box-type methane fermenter is larger than the transport volume efficiency of the cylindrical methane fermenter, the equipment cost of the methane fermenter can be suppressed. In particular, when importing a foreign-made methane fermentation tank, the equipment cost reduction effect of the methane fermentation tank is great.
-A stirrer is a substance that directly contacts organic waste and microorganisms and gives stirring power to organic waste and microorganisms.

In general, propeller blades, screw blades, etc. can be imagined, but in the present invention, instead of such rotating blades etc., it moves repeatedly up and down to act on organic waste to stir organic waste. The component which gives a stirring flow.
The drive device is a device for repeatedly moving the stirring tool up and down, and usually the stirring tool is repeatedly moved up and down by means of a hydraulic cylinder. In addition, a motor or the like may be used as the driving means.
O Heating tube refers to a tube that heats organic waste and microorganisms to maintain the methane fermentation temperature.

In the present invention, the stirrer is composed of a heating tube and exhibits two functions of stirring and heating.
○ The heat medium refers to a substance that transfers heat to the object to be heated by passing through the inside of the heating tube. Usually, water with high sensible heat and low price is selected.
O A preheating device is a device that preheats organic waste to be introduced into a methane fermentation tank to near the methane fermentation temperature in advance when the temperature in winter, etc. is significantly lower than the fermentation temperature. The organic waste is preheated to near the methane fermentation temperature and then charged into the methane fermentation tank.
There are various types of residual heat devices. For example, there are (1) a heat exchange type and (2) an electric heater.
(1) As the heat exchange type, a double tube type using a heat medium is generally used in the same manner as the heating tube described above.
(2) A heating device (not shown) using an electric heater can be exemplified by a heating device that is a heating tank and an electric heater embedded in the wall of the heating tank.
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The configuration of the present invention will be described below.
[Claim 1] A box-type methane fermenter in which microorganisms are added and methane fermentation is performed after introducing organic waste, a stirrer that repeatedly moves up and down in the box-type methane fermenter, and a stirrer that is repeated up and down A methane fermentation apparatus comprising a moving drive device.

  A characteristic component of the present invention is that a box-type methane fermenter is used. Box-type methane fermenters can be transported by trailer, ship, etc. in the same way as container transport, and the transport volume efficiency is larger than that of cylindrical methane fermenters, so the equipment costs of methane fermenters are reduced. be able to. In particular, when importing a foreign-made methane fermentation tank, the equipment cost reduction effect of the methane fermentation tank is great.

  The stirring technology of the conventional methane fermenter is that the propeller is used in the vertical cylindrical methane fermenter and the rotating stirrer is used in the horizontal cylindrical methane fermenter. It was only what was rotated and stirred. This is because the rotating tool is rotated, and so on, etc. are caught by the preconception that the methane fermentation tank is also limited to the cylindrical type, and there is a certain amount among those skilled in the art that the transportation volume efficiency is inevitable by that amount. The compliments were widespread.

  The inventor noticed for the first time that the volumetric efficiency of transportation is improved when the box-type methane fermenter is adopted rather than when the box-type methane fermenter is adopted.

  However, the technical problem is that there has been no agitation technology that provides a suitable environment in which methane-fermenting microorganisms can methane-ferment uniformly and stably in a box-type methane fermenter.

  The inventor has realized that uniform and stable stirring is possible by repeatedly stirring the stirring tool up and down, instead of rotating the rotating tool and stirring, and thus corresponds to the present invention.

When the stirrer is moved upward, the organic waste and microorganisms above the stirrer and obliquely above the stirrer flow upward along with the stirrer. On the other hand, the organic waste and microorganisms in the vicinity of the inner wall of the methane fermentation tank flow downward along with the stirring tool (see FIG. 4).
On the contrary, when the stirring tool is moved downward, the organic waste and microorganisms below the stirring tool and obliquely below the stirring tool flow downward along with the stirring tool. On the other hand, the organic waste and microorganisms in the vicinity of the inner wall of the methane fermentation tank flow upward along with the stirring tool (the reverse is the case in FIG. 4).
In this way, the stirring device is moved up and down by the drive device, whereby a stirring flow is generated inside the methane fermentation tank, and the stirring flow is reversed as the vertical movement of the stirring device is switched.
Thereby, the stirring method of the box-type methane fermenter which is not inferior to the system which rotates the stirring tool of a cylindrical methane fermenter was realizable.
In the method of moving the stirrer up and down, the time and the vertical position Z of the stirrer are expressed by the following equation depending on the time t.
Z = Z (t) ......... (1)
When the time and the vertical position Z of the stirring tool are expressed by a sine function, the expression (1) is expressed as follows.
Z = Z (t) = SIN (t) (2)
Generally, it is expressed by equation (2), but it is also possible to determine the functional form of Z (t) so that the stirring of the organic waste is uniform and well mixed.
In some cases, the above-described stirring flow causes the organic waste at the top of the stirring tool to flow in the same direction as the stirring tool, but the flow in the gap between the stirring tool and the stirring tool is in the opposite direction to the stirring tool. It is also possible to stir so that the flow becomes.
[2] The methane fermentation apparatus according to [1], wherein the stirrer comprises a heating tube for passing the heat medium through the tube and a heating device for heating the heat medium.

  A feature of the present invention is that the organic waste and microorganisms in the methane fermentation tank are warmed to a temperature suitable for methane fermentation by passing a heat medium through a tube of a heating tube that is also a stirrer. In general, inexpensive water is used as the heat medium. The heating pipe forms a closed circulation path through which the heat medium circulates, and the heat medium heated by the heating device passes through the forward pipe line and reaches the heating pipe which is also a stirring tool. As the heat medium passes through the heating tube, heat is transferred from the heat medium to the organic waste. The heat medium finishes transferring heat through the heating pipe and returns to the heating device through the return pipe.

  Thereby, the stirring tool can simultaneously exhibit two functions of stirring and heating of the box-type methane fermentation tank, and the stirring device and the heating device are made compact, so that the cost can be reduced.

Further, since the boundary layer of the stirrer periodically acts on the boundary layer of the stirrer by repetitive movement of the stirrer, efficient heat transfer can be performed to organic waste and microorganisms.
[Claim 3] The methane fermentation apparatus according to claim 2, wherein the heating tubes are arranged in a zigzag in the horizontal direction.

  The present invention is characterized in that the stirrer is constituted by a heating tube, and the heating tubes are arranged in a zigzag in the horizontal direction.

  For example, as shown in FIG. 3, the case where a heating pipe is combined with a U-shaped pipe and a straight pipe and arranged in a zigzag in the horizontal direction can be exemplified.

With this configuration of the present invention, the stirrer can function as a stirring unit and as a heating unit.
[Claim 4] The methane fermentation apparatus according to claims 2 and 3, wherein the heating tubes are arranged in a zigzag manner in the horizontal direction and in multiple stages in the vertical direction.

  According to the present invention, the heating tubes arranged in a zigzag in the horizontal direction according to the third aspect of the present invention are arranged in multiple stages.

With this configuration of the present invention, the stirring tool can function more reliably as the stirring means and as the heating means.
[5] A methane fermentation apparatus comprising a preheating apparatus installed in a box-type methane fermentation tank.

  The present invention is characterized in that the preheating device is installed in a box-type methane fermenter.

  In the prior art, the preheating device is installed outside the methane fermentation tank, and the organic waste to be input is preheated to the vicinity of the methane fermentation temperature and then input to the methane fermentation tank. For example, when the outside air temperature is low, such as a cold morning in winter, the preheater that has been warmed is cooled to the outside temperature, and the heat is wasted.

  In the present invention, since the preheating device is not directly in contact with the outside air and is heated by the heat in the methane fermentation tank, it is cooled by the outside air and does not waste heat unnecessarily as in the prior art.

In the preheating device, when the organic waste is put into the preheating device, the organic waste is preheated by a heater or the like. Temporarily, since the temperature of the input organic waste is low, the temperature of the preheating device is lowered, but the influence is not so much on the fermentation temperature of the methane fermenter.
[Claim 6] The organic waste and the microorganism are stirred by repeatedly moving the stirrer up and down inside the box-type methane fermenter in which the microorganism is added and then methane fermentation after adding the organic waste. A methane fermentation method.

  The present invention is a method invention corresponding to the first aspect of the present invention.

A characteristic component of the present invention is a step of stirring organic waste and microorganisms by repeatedly moving the stirring tool up and down.
[Claim 7] Inside the box-type methane fermenter in which organic waste is added and then microorganisms are added for methane fermentation, the organic waste and microorganisms are moved up and down repeatedly with a drive device by a stirrer composed of a heating tube. A methane fermentation method characterized by stirring organic waste and microorganisms through a heating medium through a heating tube while stirring.

  The present invention is a method invention corresponding to the invention of claim 2 which is a product invention.

  The characteristic constitutional feature of the present invention is that the organic waste and the microorganism are agitated by repetitively moving up and down with a drive device by a stirrer composed of a heating tube and the organic waste and the microorganism are agitated through a heating medium through the heating tube It is a step.

That is, it is a characteristic constituent feature of the present invention to simultaneously stir and heat the box-type methane fermenter with a stirrer composed of a heating tube.
[8] The methane fermentation method according to [7], wherein the heating tubes are arranged in a zigzag manner in the horizontal direction.

The present invention is a method invention corresponding to the invention of claim 3 which is a product invention.
[9] The methane fermentation method according to any one of [7] to [8], wherein the heating tubes are arranged in a zigzag manner in the horizontal direction and in multiple stages in the vertical direction.

The present invention is a method invention corresponding to the invention of claim 4 which is a product invention.
[10] The methane fermentation method according to any one of [6] to [9], wherein the input organic waste is preheated by a preheating device installed in the box-type methane fermentation tank.

  The present invention is a method invention corresponding to the invention of claim 5 which is a product invention.

  A feature of the present invention is to use a preheating device installed in a box-type methane fermenter, and in particular, it is a characteristic constituent feature of the present invention to install a preheating device in a box-type methane fermenter. .

  By installing the preheating device in the box-type methane fermenter, even if the outside air temperature is low as in winter, the preheating device is not exposed to the outside air and cooled down, so that heat is not wasted. The present invention can exhibit an energy saving effect.

With the above configuration of the present invention, all the problems to be solved by the invention can be achieved.
With the above-described configuration of the present invention, it was possible to realize a stirrer composed of a methane fermenter with good transport volume efficiency and sufficient stirring.
Furthermore, the said structure of this invention has implement | achieved the stirring apparatus which consists of a methane fermenter which has good conveyance volume efficiency and can be heated easily.
Furthermore, the said structure of this invention was able to implement | achieve the stirring apparatus which consists of a methane fermentation tank which made the preheating efficiency of the said organic waste high, and also improved energy-saving property.
Thus, by devising the heating device and the sales expansion device, the inside of the box-type methane fermenter was maintained at the proper temperature for methane fermentation, and the fermentation action of methane fermentation bacteria could be promoted. Could be generated.

In the methane fermentation apparatus of the present invention, from the viewpoint of improving the transport volume efficiency, a box-type methane fermenter that has not been seen conventionally is adopted. The box-type methane fermentation tank has a characteristic offensive with a drive device that repeatedly moves the stirring tool up and down.
The stirrer was composed of a heating tube for passing a heat medium, and the heating tube was arranged in a zigzag manner in the horizontal direction and arranged in multiple stages in the vertical direction.
Furthermore, the preheating device was installed in a box-type methane fermenter and aimed for energy saving effect.

  The flowchart of the methane fermentation method used for a present Example is demonstrated (refer FIG. 1).

  The organic waste 1 in which the solid organic waste and the liquid organic waste (organic waste water) are mixed is finely pulverized by the pulverizer 6 to become the slurry-like organic waste 1. The slurry-like organic waste 1 is sent to the preheating device 50 by a pump.

  The slurry-like organic waste 1 is preheated by the preheating device 50 and then charged into the box-type methane fermentation tank 10. Therefore, after being maintained in a suitable methane fermentation environment and subjected to methane fermentation treatment, the biogas 2 is collected from the upper part of the box-type methane fermentation tank 10, created by a pump, and stored in the gas holder 7. . On the other hand, the digestive juice is taken out from the upper part of the box-type methane fermentation tank 10.

Details of the first embodiment will be described below with reference to FIG.
The box-type methane fermenter 10 used in the present embodiment is shaped like a container box and is horizontal (the longitudinal direction is horizontal and the cross section is rectangular). The box-type methane fermentation tank 10 of the present embodiment may be compared with a methane fermentation tank having a circular transport volume efficiency. This is because the methane fermentation tank was made into a container-like shape to improve the transport volume efficiency.
The outer dimensions of the box-type methane fermenter 10 used in this example are 20 feet, the length (outer dimension) is 6,058 mm, the width (outer dimension) is 2,438 mm, and the height (outer dimension). Is a size of 2,591 mm.
The stirrer 10 includes a heating tube 41. The heating tube 41 is arranged in a zigzag manner in the horizontal direction and in multiple stages in the vertical direction. The heating pipe 41 is filled with a heat medium 4 (in this embodiment, water is used) and circulates.
Specifically, as shown in FIG. 3, the agitator 10 is composed of a combination of U-tubes and straight tubes and two stages of heating tubes 41 arranged in a zigzag in the horizontal direction. The heating tube 41 is firmly fixed so as not to move by the reinforcing tool 44.
The inlet and outlet of the heating tube 41 as a stirrer are connected by a flexible pipe so that the heating medium 42 can be supplied from the heating device 42 to the heating tube 41 even if the stirrer 10 repeatedly moves up and down. Yes.
The heating tube 41 is bundled with the reinforcing tool 44 at two locations of the stirring tool 10, and the fixing tools 21 and 32 suspend the stirring tool 10 from above.
Two driving devices 21 and 31 that repeatedly move the stirring tool 10 up and down are connected to the fixing tools 22 and 32.
The driving devices 21 and 31 used in the present embodiment were hydraulic driving devices. The drive devices 21 and 31 are computer controlled so as to repeatedly move the stirring tool 10 up and down. The computer controller is not shown.

  The box-type methane fermenter 10 is provided with a preheating device 50 at the upper left portion in the box-type methane fermenter 10. The preheating device 50 has a structure that does not come into direct contact with outside air.

The preheating device 50 is a heat exchange type preheating device. The heat medium superheated by the heating device circulates in the circulation path passing through the preheating device 50 and the heating device. The heat of the heat medium is transferred to the organic waste 1 by heat exchange in the preheating device 50.
In the preheating device 50, a heater for heating the input organic waste 1 may be built in the inner wall.

  In the present embodiment, the cold season in winter (outside air temperature 5 ° C.), the organic waste 1 (cooled to about 10 ° C. by the outside air) is first put into the preheater 50 and the methane fermentation temperature. Preheated to near.

  Next, after confirming that the organic waste temperature reached 37 ° C., the slurry-like organic waste 1 was charged into the box-type methane fermentation tank 10 through the organic waste charging pipe L1.

The box-type methane fermenter 10 has already been charged with the organic waste 1, and the stirrer 10 is repeatedly moved up and down by the two drive devices 21 and 31 to stir the organic waste 1 and the microorganisms. It was.
The driving devices 21 and 31 used in the present embodiment were hydraulic driving devices. The drive devices 21 and 31 are computer controlled so as to repeatedly move the stirring tool 10 up and down. Illustration of the computer control device is omitted.
The organic waste 1 and microorganisms are agitated by repetitively moving them up and down by the drive devices 21 and 31 by the agitator 10 comprising the heating tube 41, and the organic waste 1 and microorganisms are heated through the heating medium 41 through the heating medium 41. Temperature control is performed so that the methane fermentation temperature is 37 ° C.
When the methane fermentation treatment is performed, the biogas 2 mainly composed of methane is collected in the biogas chamber 60 at the upper part of the methane fermentation tank 10. The biogas 2 from the biogas chamber 60 is stored in the gas holder 7 through the biogas pipe L2.
On the other hand, when a methane fermentation process is performed, the digestive liquid 3 is taken out from the digestive liquid taking-out pipe L3 of the lower part of the methane fermentation tank 10. FIG.
Thus, even in the case of the box-type methane fermentation tank 50, the stirring can be realized as in the case of a circular methane fermentation tank, and the structure in which the stirring tool 10 is used as a heating tube can be used for a methane fermentation environment at a suitable temperature. It became possible to maintain.
Moreover, by installing the preheating device 50 in the box-type methane fermentation tank 10, the box-type methane fermentation device 100 capable of exhibiting an energy saving effect could be realized.

FIG. 1 is a flowchart of a methane fermentation process (Example 1). FIG. 2 is a drawing of a methane fermentation apparatus (Example 1). FIG. 3 is a drawing of a stirring tool (Example 1). FIG. 4 is a drawing showing the flow of organic waste when the stirrer rises.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Organic waste 2 ... Biogas 3 ... Digestion liquid 4 ... Heating medium 10 ... Box-type methane fermentation tank 50 ... Preheating apparatus 40 ... Stirring tool 21, 31 ... Drive apparatus 22, 32 ... ... Fixture 41 ... Heating tube 42 ... Heating device 44 ... Reinforcing tool 100 ... Methane fermentation apparatus

Claims (10)

A box-type methane fermenter that adds microorganisms and adds microbial fermentation after introducing organic waste, a stirrer that repeatedly moves up and down in the box-type methane fermenter, and a drive device that repeatedly moves the stirrer up and down A methane fermentation apparatus characterized by comprising. The methane fermentation apparatus according to claim 1, wherein the stirrer comprises a heating tube for passing the heat medium through the tube and a heating device for heating the heat medium. The methane fermentation apparatus according to claim 2, wherein the heating tubes are arranged in a zigzag manner in the horizontal direction. 4. The methane fermentation apparatus according to claim 2, wherein the heating tubes are arranged in a zigzag manner in the horizontal direction and in multiple stages in the vertical direction. A methane fermentation apparatus comprising a preheating apparatus installed in a box-type methane fermentation tank. A method of methane fermentation in which organic waste and microorganisms are stirred by repeatedly moving a stirrer up and down inside a box-type methane fermentation tank in which microorganisms are added and then subjected to methane fermentation after adding organic waste . Inside the box-type methane fermenter where microbial fermentation is performed by adding microorganisms after adding organic waste, the organic waste and microorganisms are stirred and heated repeatedly by a drive device using a stirrer consisting of a heating tube. A method for methane fermentation, comprising stirring organic waste and microorganisms through a heat medium through a tube. The methane fermentation method according to claim 7, wherein the heating tubes are arranged in a zigzag manner in the horizontal direction. 9. The methane fermentation method according to claim 7, wherein the heating tubes are arranged in a zigzag manner in the horizontal direction and in multiple stages in the vertical direction. The methane fermentation method according to any one of claims 6 to 9, wherein the input organic waste is preheated by a preheating device installed in a box-type methane fermentation tank.

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