JP2006122879A - Method for producing methane gas and apparatus therefor, and method for producing electricity using method for producing methane gas - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing methane gas and an apparatus therefor wherein the number of microorganism groups contained in residue is easily made constant due to recycling of the residue, and the decomposition rate of a deposit is made constant, as a result, the generation rate of methane gas is made uniform, moreover, the running cost can be suppressed and rich practicality is realized due to no need for preparing mud or sludge at every decomposition, and a method for producing electricity using the method for producing methane gas. <P>SOLUTION: A lignocellulose-based material is ground to produce a fine chip assembly. This chip assembly is deposited for a certain period of time at least until the starting of decay in a part by decay fungus is recognized, under an aerobic condition while applying moisture thereto. The deposition is charged in a silo, and water and mud or sludge is subjected to pure agar culture to proliferate the microorganism groups. Using the deposition, the residue after producing methane gas is applied thereto as an active agent for producing methane gas. The content and residue in the silo are cultured at a temperature suitable for methane fermentation under an anaerobic condition. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method and apparatus for producing methane gas, and a method for producing electricity using the method for producing methane gas. More specifically, it is a material typified by wood-based waste materials that are generated when the tree is cut, never passed through the digestive tract of animals such as livestock, and industrially used as food or feed A lignin-containing cellulosic material, i.e., a lignocellulosic resource including a woody material, which has not been subjected to a processing or decomposition step, and is unsuitable as a food or food raw material, and a method for producing methane gas The apparatus and the method for producing electricity by using a method for producing methane gas, and in particular, cultivating a group of microorganisms by pure agar culture of mud or sludge, and using that to produce methane gas first. It is characterized in that the later residue is reused as an activator for subsequent methane gas production.

  Lignocellulose is the most abundant organic substance on earth, and is composed of cellulose and hemicellulose, which are structural polysaccharides, and lignin, which is a polymer of aromatic compounds. In particular, wood-based waste materials become hot when burned, so they can be healed by waste disposal companies, and composting is difficult because it requires heating. There are cases where it is used after being mixed with a molded product or pyrolyzed, but with regard to the treatment that does not apply heat, there is currently research on whether termites can be used, and it cannot be reused. Is currently incinerated or left alone.

  On the other hand, despite the use of various waste organic materials (including livestock manure as lignocellulosic resources) as raw materials for methane fermentation and biogas production, the growth of trees and other lignocellulosic resources is also large. Lignocellulosic resources that have not passed through the gastrointestinal tract of livestock, such as the branches of trees that have been cut off, are the most abundant forms of organic matter on earth. It has been rarely used as a raw material for methane fermentation or bioproduction. Furthermore, until now, the production of biogas using garbage etc. has not produced much methane.

  Therefore, in spite of the presence of a large amount of raw materials, lignin binding that has not passed through the gastrointestinal tract of livestock, such as tree branches that have been considered unsuitable as a raw material for generating methane gas. It can be said that it is extremely valuable if methane gas can be produced using a cellulosic material or waste material used as a raw material for generating methane gas.

  By the way, when methane gas that can be generated from organic substances is released into the atmosphere in an uncontrolled state, it adversely affects the environment as a greenhouse gas having a greenhouse effect that is about 20 times that of carbon dioxide. On the other hand, if it is generated in the tank so that it does not leak into the atmosphere as a waste treatment process, it should be possible to realize both partial waste treatment and production of useful methane gas at once.

  The usefulness of methane gas is that it can be an energy source as a fuel, can be a raw material for producing hydrogen by reforming reaction and direct decomposition used in fuel cells, or a phosphoric acid fuel cell using direct biogas It can be used for

  It is well known that organic matter is converted to methane by methane fermentation by microbial action, and application to waste treatment called digestion gas or biogas (mixed gas of methane, carbon dioxide, etc.) has become popular.

  In order to achieve the above-mentioned problems, the present inventor has conducted extensive research and succeeded in developing a technology that makes it possible (Patent Document 1).

JP 2004-243188 A

  By the way, the gist of the technology is as follows. In other words, it is a material containing a woody part that was part of a plant body, never passed through the digestive tract of animals such as livestock, and processed or decomposed to make it industrially food or feed In the case of using a material containing cellulosic substance with lignin, which has not been subjected to the process and is not suitable as a food or food raw material, the material is pulverized into a fine chip aggregate. This chip aggregate is deposited for a certain period of time until the start of decay is recognized at least partially due to the attachment of decaying fungi, while maintaining the shape of the chip under aerobic conditions while applying moisture. Placing the deposit in a tank, adding water and at least 20% by weight mud or sludge to the weight of the deposit, and subjecting the tank contents to anaerobic conditions at a temperature suitable for methane fermentation. And culture, from the tank to the place to take out the methane gas.

When using raw garbage as a raw material,
(a) If necessary, grind the raw garbage brought in from the carry-in entrance, and then stir it in a stirring tank with mud or sludge rich in aqueous anaerobic bacteria.
(b) Put this agitation into a silo under anaerobic conditions and hold it in this silo for a certain period of time to decompose garbage.
(c) collecting and collecting methane gas generated in the silo from the silo;
By the way.

  Although it has been found that by adopting these methods, methane gas can be generated more efficiently than in the conventional case, the present inventor has further researched and found a method for generating a larger amount of methane gas. Have been filed as patents (application number: Japanese Patent Application No. 2004-278972, filing date: September 27, 2004). By the way, the gist of the technology is as follows.

  That is, before adding mud or sludge to the sediment or raw garbage or crushed garbage, the mud or sludge is subjected to pure agar culture, and at least gravy is added to pure agar-cultivated agar to activate it. It is characterized in that it is added as an agent to the deposits, garbage or crushed garbage. That is, it is possible to greatly promote the generation of methane gas by growing the microorganism group by pure agar culture of mud or sludge and adding it as an activator to the deposit or the garbage or the crushed garbage. it can.

  According to this technique, the generation of methane gas can be greatly promoted, but the microorganisms are grown by culturing mud or sludge in pure agar and using it as an activator for the deposit or the garbage or the crushed powder. Since the number of the microbial groups used for the treatment must be mixed every time the garbage is processed, the decomposition rate of the deposit or the garbage or the garbage after pulverization is different. There is a disadvantage that the amount of methane gas generated is not uniform and it is difficult to put it on a profitable basis. In this case, since mud or sludge has to be prepared every time the decomposition process is performed, the running cost is naturally increased, and there is a disadvantage that it is not suitable for practical use.

Therefore, as the present inventor further researched, the microorganism group was grown by pure agar culture of mud or sludge, and the residue after previously producing methane gas using it was used to generate methane gas after dredging. It has been found that it can be reused as an activator for this purpose, and that the above disadvantages can be eliminated.
That is, in the method for producing methane gas of the present invention, it is a material containing a woody part that has been part of a plant body, has not passed through the digestive tract of animals such as livestock, and is industrially The material containing cellulosic substance with lignin binding, which has not been processed or decomposed to produce food or feed, and is unsuitable as food or food raw material, This is a set of chips, and the chip assembly is maintained in the aerobic condition while giving moisture, with the shape of the chips held as it is, at least until the start of partial decay due to the attachment of decaying fungi. This sediment is put into a silo for a period of time, and a microorganism group is grown by pure agar culture of water and mud or sludge. Added as active agents for the gas generation, the culturing silo contents under anaerobic conditions at a temperature suitable to the methane fermentation, is characterized in that retrieving the methane gas from the silo.

  According to this method, mud or sludge is cultured on pure agar to grow a microorganism group, and the residue after previously producing methane gas using it is reused as an activator for producing methane gas after dredging. The number of microbial groups contained in the residue is likely to be constant, and the rate of decomposition of the deposits, the garbage or the crushed garbage is constant, and as a result, the amount of methane gas generated is uniform and profitable. There is an advantage that it is easy to put on the base. Moreover, since there is no need to prepare mud or sludge every time the decomposition process is performed, there is an advantage that running cost can be suppressed and practicality is high.

When using raw garbage as a raw material,
(a) After pulverizing raw garbage, if necessary, cultivating a group of microorganisms by pure agar culture, and using it to produce methane gas Stir with the residue of
(b) Put this agitation into a silo under anaerobic conditions and hold it in this silo for a certain period of time to decompose garbage.
(c) collecting and collecting methane gas generated in the silo from the silo;
(d) The emptied silo again includes the step used for step (b) above,
There is a feature.

  In this case, raw garbage is used as a raw material, mud or sludge is cultured in pure agar, the microorganism group is propagated, and the methane gas is first generated using the microbial group. By reusing as, methane gas can be produced efficiently and in large quantities.

When the mud or sludge is cultured on pure agar, the mud or sludge is preferably cultured on the agar culture bed at a certain temperature, for example, about 35 ° C. for about a week. The amount of mud or sludge used for pure agar culture is preferably about 500 g to 1 kg with respect to 2 kg of the agar culture bed. In addition, it is desirable to add gravy to agar that has been subjected to pure agar culture, and it may be further cultured for about one week after the addition of gravy.
By culturing mud or sludge in pure agar, the microbial group can be grown, and by adding gravy to pure agar-cultured agar and subsequent culture, the microbial group can be further grown. By reusing the residue after previously producing methane gas using as an activator for the subsequent methane gas production, generation of methane gas can be further promoted.
“Meat soup” refers to a gelatinized form of boiled beef, pork, chicken or other various meat fats, and the amount added is preferably about 10 g. In order to reduce the cost, it is desirable to use the cheapest meat and the unnecessary fat.

  More specifically, the mud or sludge is suitable for the habitat of both hydrogen-producing bacteria and methane-producing bacteria and contains these fungi, or mud soil in a lotus field with water or It is selected from the group consisting of sludge, sludge or sludge at the bottom of stagnation of river water that contains organic matter to some extent due to sludge, domestic wastewater, hot spring bath drainage, etc., and sludge or sludge at the bottom of lakes that contain a lot of organic matter Muddy soil or sludge.

  “Muddy soil” means a muddy soil with physical properties such as mud. When “sadro” means mud containing organic matter precipitated on the bottom of the water, it can be included in “mud”. “Sludge” may also be included in “mud”. Where a weight percentage of such mud relative to the weight of the ground decay decay chip deposit is indicated, it is expressed as a weight percentage of such moisture content and not a percentage of dry matter.

Regarding "mud soil suitable for the habitat of both hydrogen-producing bacteria and methane-producing bacteria and containing these bacteria", the nutrients used by hydrogen-producing bacteria and methane-producing bacteria are said to be different, but anaerobic It is thought that there are methane producing bacteria where hydrogen producing bacteria exist.
For “mud or sludge that is suitable for the habitat of both hydrogen-producing bacteria and methane-producing bacteria and contains these bacteria”, as an example, in a place where the soil is also rich in proteolysates or organic matter. If the soil is anaerobic (eg, at the bottom of the water), the water is not flowing and stagnant, and the water is not soiled (the water above is clear) Such mud or sludge is thought to be suitable for the habitat of both hydrogen producing and methane producing bacteria.
Mud or sludge in lotus field with water, mud or sludge at the bottom of river stagnation that contains organic matter to some extent due to domestic wastewater or hot spring bath drainage, etc. and lakes rich in organic matter The bottom mud or sludge meets these conditions.

On the other hand, examples of woody materials include one or more selected from the group consisting of disposal materials generated by cutting branches and trunks of trees, fallen trees, discarded trees and parts thereof, and deciduous leaves, or Mention may be made of a mixture of a substantial or major amount and one or more selected from the group consisting of waste vegetables, weed litter, straw and raw litter. Waste wood and wood chips generated in the lumbering process and demolition may be used as woody raw materials, but in recent years, mainstream foreign timber has been invaded by seawater, and new construction materials contain chemical substances. In many cases, it is not suitable.
The wood material is preferably crushed to such an extent that it can pass through the eyes of an 8 mm sieve. Since woody waste contains twigs or is fibrous and elongated, it also includes fragments with a length longer than 8 mm. For example, it can be pulverized to about 2 cm in advance, and then pulverized to such an extent that it passes through the eyes of an 8 mm sieve.

  About 60% of the moisture content of the entire sediment when the wood material crushed chips are deposited and decayed is preferable. At the stage of sedimentation and decay, it is only necessary to ventilate the water to make it aerobic, and no other mixing is necessary. Mixing can be counterproductive. For example, when rot was attempted by mixing residues of the fungi of sea bream (nameko and shimeji), there was an adverse effect on the subsequent methane fermentation stage. It was observed that the temperature rose to about 50-60 ° C. during the deposition stage. The deposition period is preferably 20-30 days. In other words, it is the time when the decay has started a little after the start of decay, and the shape of the chip is maintained.

The reason why methane can be efficiently produced by using the wood material crushed decay chips as raw materials is presumed to be through the following process. Aerobic decay is caused by the fact that the wood decay fungus adheres to the surface of the ground material due to the accumulation of the ground material of the wood material under aerobic conditions, and the ground material that has been partially decayed is immersed in water. Bacteria produce fine bubbles on the surface of the pulverized product. In the state where the oxygen in the bubble is exhausted, the decaying bacteria die, and instead, the anaerobic hydrogen-producing bacteria in the mud or sludge are easily propagated at the interface between the bubble and water. Hydrogen-producing bacteria break down cellulose, hemicellulose, etc., the bond between lignin and cellulose is destroyed and the pulverized product becomes soft, and the methane-producing bacteria that existed in the mud or sludge that nourished it by the growth of hydrogen-producing bacteria It is thought to breed and produce methane.

  On the other hand, even when raw garbage is used as a raw material, methane can be efficiently produced because the raw garbage is decomposed by the propagation of hydrogen-producing bacteria and is present in mud or sludge that nourishes hydrogen-producing bacteria. It is thought that the methane-producing bacteria that had been bred grow and produce methane.

  In the present invention, in generating methane gas, the above-described mud or sludge is subjected to pure agar culture to grow a microbial group, and without using it, the residue after previously producing methane gas is discarded. By reusing it as an activator for the subsequent methane gas production, methane gas can be produced efficiently and in large quantities.

The residue may be used as it is as an activator for methane gas generation after drought, but it is preferable to transfer the liquid component separated from the residue to the incubator as a seed bed and further propagate the microorganism group until reuse . In this case, the microorganisms contained in the liquid separated from the residue can be further grown in an incubator, and reused as an activator for the subsequent generation of methane gas further promotes the generation of methane gas. Can be made.

  On the other hand, in the apparatus for producing methane gas of the present invention, it is a material containing at least a woody part that was part of the plant body, never passed through the digestive tract of animals such as livestock, and It is obtained by crushing a material containing cellulosic substance with lignin, which has not been processed or decomposed industrially to become food or feed and is unsuitable as food or food raw material. Accumulated fine chips were accumulated for a certain period of time until the start of decay was recognized at least partially due to the attachment of decaying bacteria under the aerobic condition while giving moisture, with the shape of the chips kept intact Sediment or garbage is mixed with mud or sludge in pure agar to grow microbial populations, and then mixed with the residue after previously producing methane gas. A plurality of anaerobic silos for holding for a certain period of time, and a gas holder for keeping the inside of the silo in use to collect gas at an appropriate pressure at which microorganisms contained in the residue can act And a gas storage means for storing methane gas generated in the silo.

  By using this device, mud or sludge is cultured in pure agar to grow a microorganism group, and the residue after previously producing methane gas using it is reused as an activator for the production of methane gas after dredging. As a result, methane gas can be generated efficiently and in large quantities. In particular, the silo in use for collecting gas is maintained at an appropriate pressure at which the microorganisms contained in the residue can be activated by the gas holder provided in this apparatus. Methane gas can be generated under conditions that are fully active and can be stored in the gas storage means.

  It is desirable to provide a pressure pump for keeping the gas pressure in the gas holder below the upper limit pressure and above the lower limit pressure and feeding back the methane gas extracted from the silo to the silo in use. In this case, the inside of the gas holder is kept below the upper limit pressure and above the lower limit pressure by the pressurization pump, and the methane gas taken out from the silo by the pressurization pump can be fed back to the silo in use. The decomposed material in the silo inside can be stirred.

  It is desirable to provide an incubator for further growing the microorganism group contained in the residue in the silo after gas generation until reuse. In this case, the residue remaining in the silo after gas generation can be transferred to an incubator, and the microorganism group contained in the residue can be further grown until reuse. Therefore, by reusing the residue obtained by further growing the microorganism group in the incubator as an activator for producing methane gas after drought, methane gas can be generated efficiently and in large quantities in the silo. It can be stored in a gas storage means. The incubator is also for temporarily storing the residue after growing the microorganism group until reuse.

  It is desirable to provide a secondary container for sequentially filling the plurality of gas storage means with methane gas at an appropriate pressure. In this case, since the secondary storage device sequentially fills the plurality of gas storage means with the appropriate pressure with the appropriate pressure, the plurality of gas storage means can be automatically and sequentially filled with the appropriate pressure with the appropriate pressure.

In order to generate electricity, methane gas may be supplied to the raw material for the fuel cell. This is very convenient because the production of methane can be used directly in combination with a fuel cell.

  According to the method of claim 1, the residue after the microbial group is grown by pure agar culture of mud or sludge and the methane gas is first generated using it is used as an activator for the methane gas generation after dredging. Since it is reused, the number of microbial groups contained in the residue is likely to be constant, and there is an advantage that the amount of methane gas generated is uniform and easily placed on the profit base. Moreover, since there is no need to prepare mud or sludge every time the decomposition process is performed, there is an advantage that running cost can be suppressed and practicality is high. Furthermore, the raw material cost is low, and the lignocellulosic resources and the mud or sludge are agar-cultured pure agar to grow the microorganism group, and the residue after producing methane gas using it, By reusing as an activator for the subsequent methane gas production, methane gas can be produced efficiently and in large quantities.

  According to the method of claim 2, raw garbage is used as a raw material, mud or sludge is cultured in pure agar, and a microorganism group is propagated. Using this, methane gas is first generated, and the residue is used to produce methane gas after dredging. By reusing as an activator for methane, methane gas can be produced efficiently and in large quantities.

According to the method of claim 3, the microorganism group contained in the liquid separated from the residue can be further propagated in the incubator, and by reusing it as an activator for generating methane gas after drought, methane gas Can be generated efficiently and in large quantities.

  According to the method of claim 4, the methane gas is efficiently produced in a large amount by using mud or sludge that does not incur raw material costs, is easily available, and does not have to worry about depletion even when used. Can be generated.

  When the apparatus according to claim 5 is used, the microorganisms are grown by pure agar culture of mud or sludge, and the residue after previously producing methane gas using it is used to produce methane gas after dredging. By reusing as an activator, methane gas can be produced efficiently and in large quantities. In particular, the silo in use for collecting gas is maintained at an appropriate pressure at which the microorganisms contained in the residue can be activated by the gas holder provided in this apparatus. Methane gas can be generated under conditions that are fully active and can be stored in the gas storage means.

  According to the sixth aspect of the present invention, the inside of the gas holder is maintained at a pressure not more than the upper limit pressure and not less than the lower limit pressure by the pressurizing pump, and the methane gas taken out from the silo by the pressurizing pump can be fed back to the silo in use. The gas to be decomposed in the silo in use can be stirred.

  According to the invention of claim 7, the microbial group can be further propagated in the incubator, and by reusing it as an activator for generating methane gas after drought, methane gas is efficiently used in the silo, Moreover, it can be generated in large quantities and stored in the gas storage means.

  According to the eighth aspect of the invention, since the secondary storage unit sequentially fills the plurality of gas storage units with methane gas at an appropriate pressure, the plurality of gas storage units are automatically and sequentially filled with the methane gas at an appropriate pressure. can do.

  According to the invention described in claim 9, since the production of methane can be directly combined with the fuel cell and used, it is very convenient.

Hereinafter, embodiments of the present invention will be described in detail. However, the example shown below shows an example to the last, and is not limited to them.

(1) Selection of wood materials In the previous application (Japanese Patent Application Laid-Open No. 2004-243188) related to the same applicant, the wood materials include both conifers and broadleaf trees, and both coniferous and broadleaf trees. It is proved that it is good to use abandoned trees, cut branches and leaves (proportion of normal garden tree pruning), cedar leaves and trunks, deciduous trees, fallen leaves, birch leaves and trunks, pine leaves and trunks, etc. Has been. Then, they are pulverized by a pulverizer to obtain a pulverized product (chip) having a size passing through an 8 mm sieve. If pulverization at one time is difficult, a coarsely pulverized product may be used and then finely pulverized again.

(2) Partial decay processing of wood raw material In the previous application (Japanese Patent Application Laid-Open No. 2004-243188) related to the same applicant, the pulverized chips are deposited and moistened at intervals of once every two days. It has been proven good to keep it for 20 days to 1 month. Visually confirm that the internal temperature is about 50 to 60 ° C. and that aerobic heterotrophs recently (mainly white rot fungi and filamentous rot fungi) begin to attach naturally (in about a week). Yes. It has also been confirmed that when oxygen is supplied, earlier attachment of aerobic bacteria is recognized by activation of the aerobic bacteria. In large-scale production, this decaying fungus treatment process only requires water from time to time, and can be deposited outdoors, so it can be used in a relatively small area, so the period of 20 days to 1 month will deteriorate the efficiency of the process. Must not.

(3) Selection of mud In the previous application (Japanese Patent Application Laid-Open No. 2004-243188) related to the same applicant, partly obtained in the step (2), that is, the partial decay treatment process of the woody material. 1 kg of wood material crushed material decay chip (hereinafter referred to as pulverized product decay chip or wood material crushed material decay chip) with decaying fungi, which are decaying, are put in a 10 liter container, 50% by weight of water is added to the weight of the crushed material decay chip, and 30 to 50% by weight of various mud is added to the weight of the crushed material decay chip. Tried to find out. As a result, it has been proved that the mud in the lotus root field is the most suitable as the mud component, and the mud in the downstream of the Muddy River is the second most suitable. In this experiment, among the mud components that can be used for the generation of methane gas, the mud of the lotus root field that has the best results is used as the mud component.

(4) Pure Agar Culture of Mud In the present invention, the mud is subjected to pure agar culture before adding the mud or sludge (hereinafter simply referred to as mud) to the crushed material decay chip. When the mud is cultivated in pure agar, the mud is preferably cultivated for about a week while maintaining a constant temperature, for example, about 35 ° C., on the agar culture bed. In this case, the amount of mud is preferably about 500 g to 1 kg with respect to 2 kg of the agar culture bed. By culturing mud or sludge with pure agar, the microorganism group can be grown.

(5) Addition of gravy Add at least gravy to agar cultured on pure agar. “Meat broth” refers to a gelatinized form of boiled beef, pork, chicken and other various meat fats, and the amount added is preferably about 10 g. After adding gravy to pure agar-cultured agar, it is preferable to maintain a certain temperature, for example, about 35 ° C., and further culture for about one week. By adding gravy to pure agar-cultured agar and subsequent culture, the microorganism group can be further grown.

(6) Pure agar culture of mud or sludge to grow microorganisms and use it to recover the residue after first producing methane gas 20 kg of crushed decayed chips into 200 liters of anaerobic conditioned silo Add 50% by weight of water to the weight of the crushed material decay chip, further culture the mud or sludge in pure agar, add the meat juice to it, and culture the agar for about a week. Air purge with nitrogen is performed by adding 50% by weight. Then, methane gas can be generated in the silo. The temperature in the silo is kept at 35 ° C. A semi-solid content and a liquid content are separated from the residue generated at that time, and at least the liquid content is recovered and reused for the generation of methane gas. The semi-solid content can be used as an additive at the time of manufacturing compost and soil.

(7) Culture of recovered residue The residue after producing methane gas may be used as it is, and methane gas may be generated by using the microorganism group contained therein as an activator. It is transferred to the incubator as a bed, and 0.5 kg of gravy and 4 kg of well water (soft water) are added to the incubator, air purge with nitrogen is performed, and the microorganism group is further grown for one week until reuse. In this case, a group of microorganisms contained in the liquid separated from the residue can be further grown in an incubator, and generation of methane gas can be further promoted by using this residue.

(8) Methane gas generation Instead of using pure agar cultured in mud or sludge in step (6) and adding meat juice to it, the residue cultured in step (7) Used to generate methane gas in the same manner as described above. At that time, the silo was in a low oxygen state, but the temperature therein was kept at 35 ° C., and the amount of methane gas generated after 2 weeks was measured. The measurement of methane gas was performed based on the JIS K 2301 gas chromatography (TCD) method. In addition, since tap water may have a bactericidal action, the water used here used well water (soft water).

(9) Collection of methane gas Two weeks after charging into the silo, methane gas was stored in a 100-liter tank and the value was measured.

Example 1
The collected amount of methane gas produced by the steps (1) to (9) is shown in Table 1 in volume%. In Example 1, the lotus soil in the lotus root field is cultured in pure agar, and after adding meat juice to the agar, the microorganism group is further cultured to proliferate the microorganism group. Used in culture.

(Comparative Example 1)
On the other hand, the mud soil of lotus root was cultured on pure agar, and after adding meat juice to the agar, the same experiment as in Example 1 was performed using the further cultured agar as an activator for methane gas production. The data in that case is also shown in Table 1 as Comparative Example 1.

As is clear from Table 1, in the case of Example 1 (the lotus field mud was subjected to pure agar culture, and after adding gravy to the agar, the culture was further cultured to grow the microbial community, which was used to methane gas first. In the case of Comparative Example 1 (the lotus soil in the lotus root is cultured on pure agar, and the gravy is added to the agar). It was proved that the amount of methane gas generated was greatly increased compared to the case of using agar further cultured after the addition.
It should be noted that the increase in the amount of methane gas produced after 2 weeks from the preparation is that prior applications (Japanese Patent Application Laid-Open No. 2004-243188 and Japanese Patent Application No. 2004-278972, filing date: September 27, 2004) related to the same applicant. The measurement from the preparation to 2 weeks and the measurement after 2 weeks were omitted.

  Further, it has already been demonstrated in a previous application (Japanese Patent Application Laid-Open No. 2004-243188) related to the same applicant that the amount of methane generated does not change even if the amount of mud (accelerator) is changed. It can also be applied to. That is, even if the amount of mud is changed while a necessary and sufficient amount is supplied, it does not greatly affect the change in the amount of methane produced. This is thought that mud works to promote methane generation in a certain range rather than as a raw material for methane. For example, the idea that it contributes to the supply of microorganisms seems to hold.

Next, an apparatus for producing methane gas by this method will be described in detail with reference to FIG.
FIG. 1 is a schematic diagram showing the entire apparatus. In FIG. 1, reference numeral 1 is an anaerobic silo for generating methane gas, and a plurality (four in the drawing) are provided side by side. Reference numeral 2 is a desulfurizer for removing hydrogen sulfide mixed in the gas generated in the silo 1, and reference numeral 3 is included in the residue in the silo in use to collect the gas. A gas holder for maintaining a proper pressure at which microorganisms can act. Reference numeral 4 indicates that the gas pressure in the gas holder 3 is kept below the upper limit pressure and above the lower limit pressure, and the methane gas taken out from the silo 1 is fed back to the silo 1 in use. This is a pressurizing pump.
Reference numeral 5 is a mist separator for separating water vapor generated from the silo 1 and oil mist discharged from the pressure pump 4 from methane gas, and reference numeral 6 is an appropriate pressure in a plurality of tanks 7 and 7. It is a secondary container used to fill methane gas.
The devices 1 to 7 communicate with each other through pipes indicated by solid lines so that methane gas generated in the silos 1 and 1 can be finally stored in a plurality of tanks 7 and 7 sequentially.

Reference numeral 8 denotes an incubator for further growing the microorganism group contained in the residue in the silo 1 after gas generation until reuse.
Further, reference numeral 9 denotes a substance to be decomposed in the silo 1, that is, a crushed material decay chip inserted in the silo 1 and mud or sludge, and a microorganism group is grown by pure agar culture, and methane gas is first used by using it. In order to keep the temperature of the generated residue at an appropriate temperature of 35 ° C., it is a gas boiler for circulating and supplying hot water, and branches from the middle of the pipe connecting the outlet side of the secondary container 6 and the inlet side of the tank 7. It is arranged at the position.

Each silo 1, 1 is a material containing at least a woody part that was part of the plant body, has never passed through the digestive tract of animals such as livestock, and is industrially A set of fine chips obtained by crushing a material containing cellulosic substances bound to lignin, which has not been processed or decomposed to become feed and is unsuitable as a food or food ingredient Put your body in. And the start of decay is recognized at least partially due to the attachment of decaying fungi in a state where the shape of the chip is maintained as it is under aerobic conditions while moistening the aggregate of fine chips thrown into the silo 1 The sediment or garbage deposited for a certain period of time is mixed with mud or sludge in pure agar to grow the microbial community, and then the residue after producing methane gas is mixed with the mixture. Methane gas can be generated by keeping it in an airtight state for a certain period.

  The silos 1 and 1 communicate with each other by a pipe 1f (shown by a dotted line in FIG. 1) branched from a pipe 9a extending from the gas boiler 9 to the silos 1 and 1 side, and a pipe indicated by a solid line 1 g communicates with a nitrogen gas tank 10 for air purge with nitrogen. In each silo 1, 1, the sediment or raw garbage and the mud soil or sludge put into the silo are agar-agar cultured to proliferate the microorganism group, and the residue after previously producing methane gas using it. A temperature sensor 1a for managing the temperature of the water and a warm water heater coil 1b for heating are provided. Each silo 1 and 1 is provided with a nitrogen filling port 1c and an air release valve 1d so that nitrogen air purge can be performed in each silo. Further, in each silo 1, 1, methane gas fed back by the pressurizing pump 4 is discharged from the bottom of the silo 1 in use, and a gas discharge port 1e for stirring the aggregate of fine chips and the residue. Is provided.

  As described above, the desulfurizer 2 is used to remove (desulfurize) hydrogen sulfide mixed in the gas generated in the silo 1, and a plurality of silos while alternately desulfurizing and replacing activated carbon. A plurality (two in the drawing) are provided so that gas can be successively generated in the first and the first. Switching between the plurality of desulfurizers 2 and 2 can be performed by alternately switching the electromagnetic three-way valve 2a provided on the suction side of both desulfurizers 2 and 2. Activated carbon is used to adsorb it to remove (desulfurize) hydrogen sulfide, and can be used with small rocks.

In the desulfurizer 2, when the activated carbon is replaced, it is necessary to recover the methane gas remaining therein so that it is not released into the atmosphere. The suction side valve 2b of the desulfurizer 2 to be replaced with activated carbon is closed, the discharge side electromagnetic three-way valve 2c of the desulfurizer 2 is set to the pressure pump 4 side, and the discharge side electromagnetic three-way valve of the pressure pump 4 is set. By operating the pressurizing pump 4 with 4b as the secondary container 6 side, the methane gas can be recovered by sending it into the secondary container 6.

Further, in the desulfurizer 2, it is necessary to perform an air purge in order to discharge the air that has entered the activated carbon after it is replaced. Close the suction side valve 2b of the desulfurizer 2 after replacement of the activated carbon, set the discharge side electromagnetic three-way valve 2c of the desulfurizer 2 to the pressure pump 4 side, and set the discharge side electromagnetic three-way valve 4b of the pressure pump 4 to By operating the pressurizing pump 4 in an open state, an air purge for discharging the air that has entered the desulfurizer 2 can be performed.
In addition, each of the suction-side electromagnetic three-way valve 2a, the discharge-side electromagnetic three-way valve 2c, the suction-side electromagnetic three-way valve 4a, and the discharge-side electromagnetic three-way valve 4b of the desulfurizer 2 is controlled by a control panel. By controlling, air purge for desulfurization, methane gas recovery, and air discharge in the desulfurizer 2 can be performed without malfunction.

As described above, the gas holder 3 is used to keep the inside of the silo 1 being used to collect gas at an appropriate pressure at which microorganisms contained in the residue can act, and the upper limit pressure switch 3a, A lower limit pressure switch 3b is provided. If the gas pressure in the silo 1 in use is increased to collect gas, the activity of microorganisms is weakened. Therefore, it is necessary to maintain the silo 1 at an appropriate pressure by the gas holder 3.
When the gas pressure in the gas holder 3 reaches an upper limit pressure (for example, 2 KPa), the pressure pump 4 is automatically operated to transfer the gas to the secondary container 6. When the gas pressure in the gas holder 3 reaches a lower limit pressure (for example, 1 KPa or less), the automatic operation of the pressurizing pump 4 is terminated. At that time, the solenoid valve 3c installed at the discharge port of the gas holder 3 is also unit-controlled by the control panel.
Reference numeral 3d denotes a pressure gauge provided in the gas holder 3.

  As described above, the pressurizing pump 4 keeps the gas pressure in the gas holder 3 below the upper limit pressure and above the lower limit pressure, and feeds back the methane gas taken out from the silo 1 to the silo 1 in use. In order to keep the gas pressure in the gas holder 3 below the upper limit pressure and above the lower limit pressure, the gas in the gas holder 3 is pumped to the secondary container 6. In order to give a function as a vacuum pump, it is an oil seal type. The operation of the pressurizing pump 4 can be switched between unit control by the control panel and manual operation at the site.

  As described above, the mist separator 5 is for separating the water vapor generated from the silo 1 and the oil mist discharged from the pressure pump 4 from the methane gas, and can measure the pressure in the mist separator 5. A pressure gauge 5a that can be used is provided.

As described above, the secondary container 6 is used to fill the plurality of tanks 7 and 7 with methane gas at an appropriate pressure, and each tank 7 is operated by an upper limit pressure switch 6a provided therein. , 7 can be opened and closed by unit control by the control panel, and the tanks 7 and 7 can be automatically filled with methane gas sequentially at an appropriate pressure. . The tank 7 is a gas storage means for finally storing methane gas generated in the silo.
It is preferable that the valve of the tank 7 can be manually closed at the site by displaying on the control panel that methane gas is filled in one tank 7.
The secondary container 6 is provided with a pressure gauge 6b that can measure the pressure therein.

As described above, the incubator 8 is for further growing the microorganism group contained in the residue in the silo 1 after gas generation until reuse. Since the microbial group used for methane gas generation has a short life cycle of about 48 hours, the microbial group contained in the residue in the silo 1 is transferred to the incubator 8 after the gas generation is completed, and further proliferated until reuse. Can be made. The incubator 8 is also for temporarily storing the residue after the microorganism group has been propagated until reuse.
The semi-solid content and the liquid content are separated from the residue generated during the generation of methane gas, and at least the liquid content is recovered and reused for the subsequent generation of methane gas. The semi-solid content can be used as an additive at the time of manufacturing compost and soil.

As described above, the gas boiler 9 purely agar-cultures the material to be decomposed in the silo 1, that is, the crushed material decay chip and the mud or sludge charged into the silo 1 to proliferate the microorganism group, and uses it. In order to keep the temperature of the residue after generating methane gas at an appropriate temperature of 35 ° C., a gas boiler for circulatingly supplying hot water.
The gas boiler 9 is arranged at a position branched from the middle of the pipe connecting the outlet side of the secondary container 6 and the inlet side of the tank 7. From the gas boiler 9, a pipe 9 a is connected to each silo 1, 1 side. The gas boiler 9 and the silos 1 and 1 communicate with each other by a pipe 1f (indicated by a dotted line in FIG. 1) that extends from the pipe 9a.

When a heating boiler is used as the gas boiler 9, the discharge temperature is too high, so it is preferable to use a hot water storage boiler. Then, it is desirable to install a cistern pump (not shown) so that the gas can be returned to the water inlet of the gas boiler 9 and circulate, and the boiler 9 absorbs water.
Since the gas pressure for burning the gas boiler 9 may not be constant, the gas boiler 9 can be operated safely if a pressure regulator 9b is provided so that the rated combustion gas pressure of the boiler can be maintained. .

  Thus, by using this apparatus provided with the devices 1 to 10 related to each other, mud soil or sludge is subjected to pure agar culture to grow a microorganism group, and the residue after previously producing methane gas using it. Is reused as an activator for the production of methane gas after soot, so that methane gas can be produced efficiently and in large quantities. In particular, the silo 1 in use for collecting gas is maintained at an appropriate pressure at which the microorganisms contained in the residue can be activated by the gas holder 3 provided in the apparatus. It is possible to generate methane gas under the condition that the microorganism group is sufficiently active, and it is possible to automatically and sequentially fill the plurality of tanks 7 and 7 with an appropriate pressure.

  In FIG. 1, reference numeral 11 denotes a generator for generating and supplying necessary electric power in the apparatus using methane gas generated in the apparatus, and includes an outlet side and a tank of the secondary container 6. 7 is arranged at a position branched from the middle of the pipe connecting the inlet side of 7. In FIG. 1, reference numeral 12 denotes a power transmission / reception panel for selling electricity generated by using this apparatus to an electric power company. If this apparatus is used, mengas can be generated extremely efficiently and consumed. Since there is a high possibility that the power will not be cut off, the power company will use the surplus power. If this generator 12 is a residual heat utilization type, the said gas boiler 9 is unnecessary.

1 is an overall schematic diagram showing an example of an apparatus for producing methane gas according to the present invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Silo, 2 ... Desulfurizer, 3 ... Gas holder, 3a ... Upper limit pressure switch, 3b ... Lower limit pressure switch, 4 ... Pressure pump, 5 ... Mist separator, 6 ... Secondary container, 7 ... Tank, 8 ... Incubator, 9 ... gas boiler, 10 ... nitrogen gas tank.

Claims (9)

A material containing a woody part that was part of the plant body, never passed through the digestive tract of animals such as livestock, and processed or decomposed to produce food or feed industrially A crushed material containing cellulosic lignin, which has not been received and is unsuitable as a food or food ingredient, to form an aggregate of fine chips,
This aggregate of chips is deposited for a certain period of time until at least partial start of decay due to adhesion of decaying fungi, with the shape of the chip maintained as it is under aerobic conditions while giving moisture.
This sediment is put into a silo, and water and mud or sludge is cultured on pure agar to proliferate the microorganism group, and the residue after previously producing methane gas using it is used as an activator for the production of methane gas after dredging. In addition,
Culturing the silo contents under anaerobic conditions at a temperature suitable for methane fermentation,
A method for producing methane gas, comprising extracting methane gas from the silo. (a) After pulverizing raw garbage, if necessary, cultivating a group of microorganisms by pure agar culture, and using it to produce methane gas Stir with the residue of
(b) Put this agitation into a silo under anaerobic conditions and hold it in this silo for a certain period of time to decompose garbage.
(c) collecting and collecting methane gas generated in the silo from the silo;
(d) The emptied silo again includes the step used for step (b) above,
A method for producing methane gas, characterized in that The method for producing methane gas according to claim 1 or 2, wherein the liquid component separated from the residue is transferred to an incubator as an inoculum bed and the microorganism group is further grown until reuse.   Use mud or sludge, which is suitable for the habitat of both hydrogen-producing bacteria and methane-producing bacteria, and contains these fungi, or mud or sludge in a lotus field with water, living Mud or sludge selected from the group consisting of mud or sludge at the bottom of the river stagnation containing organic matter to some extent due to drainage or hot spring bath drainage, etc. The method for producing methane gas according to claim 1 or 2, wherein sludge is used. at least,
A material containing a woody part that was part of the plant body, never passed through the digestive tract of animals such as livestock, and processed or decomposed to produce food or feed industrially Aerobic while giving moisture to a collection of fine chips obtained by crushing a material containing cellulosic lignin bound, which has not been received and is unsuitable as a food or food ingredient Under the conditions, with the shape of the chip kept intact, pure agar culture of sediment or garbage deposited for a certain period until at least partial start of decay due to adherence of decaying fungi, and mud or sludge is cultured. A plurality of anaerobic silos provided to multiply the microorganism group and mix the residue after the methane gas has been generated with the microorganism group, and to maintain the mixture in an airtight state for a certain period of time;
A gas holder for keeping the inside of the silo in use to collect gas at an appropriate pressure at which microbes contained in the residue can act;
Gas storage means for storing methane gas generated in the silo;
An apparatus for producing methane gas, comprising:   6. The pressurizing pump for keeping the gas pressure in the gas holder below the upper limit pressure and above the lower limit pressure and feeding back the methane gas taken out from the silo to the silo in use. A device that produces methane gas.   The apparatus for producing methane gas according to claim 5 or 6, further comprising an incubator for further growing a microorganism group contained in the residue in the silo after gas generation until reuse. .   6. The apparatus for producing methane gas according to claim 5, further comprising a secondary container for sequentially filling the plurality of gas storage means with methane gas at an appropriate pressure. A method for producing electricity using the method for producing methane gas according to any of claims 1 to 4, comprising the step of supplying methane gas to a raw material for a fuel cell to generate electricity.

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