Organic matter treatment device

Abstract

To provide an organic matter treatment apparatus that does not adopt a two-tank system, and can methanize carbon dioxide in a biogas while avoiding occurrence of a situation in which methane fermentation stops.SOLUTION: An organic matter treatment apparatus comprising a methane fermentation tank 10 to which organic matter is supplied comprises: a carrier T which is arranged in the methane fermentation tank 10 in a state in which a part thereof is immersed in a methane fermentation liquid in the methane fermentation tank 10 and the remainder is positioned in a space 12 above a liquid level of the methane fermentation liquid, or in a state in which a liquid is positioned in the space 12 above the liquid level, and is impregnated with the methane fermentation liquid; and hydrogen supply means 20 which supplies hydrogen to the space 12 above.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to an organic matter treatment apparatus that treats organic matter using methane fermentation.

Background Art

[0002] Biogas obtained by methane fermentation of organic matter contains carbon dioxide and various components in addition to methane. In recent years, for the purpose of using biogas as city gas, the development of so-called biomethanation technology for converting carbon dioxide in biogas into methane by microorganisms has been promoted. For example, Non-Patent Document 1 proposes a method of methanating carbon dioxide in biogas by methane bacteria by blowing hydrogen into a liquid containing methane bacteria.

[0003] By the way, in the methane fermentation process, organic acids such as propionic acid are generated from organic matter via a plurality of substances, acetic acid is generated from this organic acid, and finally methane is generated from acetic acid. Here, when performing methane fermentation treatment in a state where the organic matter load is high (the production rate of organic acid is high), by blowing hydrogen into the methane fermentation liquid, the production of acetic acid from the organic acid is inhibited, the organic acid in the methane fermentation liquid increases, and the pH of the solution decreases. As a result, the activity of bacteria involved in methane production from acetic acid decreases, and there is a risk that methane fermentation will finally stop.

[0004] Therefore, in Non-Patent Document 1, in order to avoid the stop of methane fermentation, a two-tank system is adopted, and biogas is generated by methane fermentation in the first tank, and it is proposed to blow hydrogen in the second tank to methanate carbon dioxide.

Prior Art Documents

Non-Patent Documents

[0005]

Non-Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, when adopting a two-tank type as in the technology described in Non-Patent Document 1 above, enlargement of the apparatus is inevitable, and equipment for stably supplying the methanogenic fermentation liquid and biogas from the first tank to the second tank is required, so complication of the apparatus is also inevitable.

[0007] The present invention has been made in view of the above circumstances, and an object thereof is to provide an organic matter treatment apparatus that can achieve both methanogenesis of organic matter and methanation of carbon dioxide in biogas while avoiding the occurrence of a situation where methanogenesis stops without adopting a two-tank type.

Means for Solving the Problems

[0008] The characteristic configuration of the organic matter treatment apparatus according to the present invention for achieving the above object is an organic matter treatment apparatus including a methanogenic fermentation tank to which organic matter is supplied, a carrier disposed in the methanogenic fermentation tank in a state where a part is immersed in the methanogenic fermentation liquid in the methanogenic fermentation tank and the remainder is located in a space above the liquid level of the methanogenic fermentation liquid, or in a state where it is located in a space above the liquid level of the methanogenic fermentation liquid, and impregnated with the methanogenic fermentation liquid, and hydrogen supply means for supplying hydrogen to the above space.

[0009] According to the above characteristic configuration, a part of the carrier is immersed in the methanogenic fermentation liquid in the methanogenic fermentation tank and the remaining part is located in the space above the liquid level of the methanogenic fermentation liquid, or the carrier is arranged in the space above the liquid level of the methanogenic fermentation liquid, and carbon dioxide in the biogas existing in the space above the liquid level can be methanated by the methanogenic bacteria in the methanogenic fermentation liquid impregnated in this carrier. That is, according to the above characteristic configuration, in the methanogenic fermentation tank, without blowing hydrogen into the methanogenic fermentation liquid, while performing methanogenic fermentation in the methanogenic fermentation liquid, carbon dioxide in the biogas generated by the methanogenic fermentation can be methanated by the methanogenic bacteria held on the carrier.

[0010] Therefore, according to the above characteristic configuration, without adopting a two-tank type, in one methanogenic fermentation tank, while avoiding the occurrence of a situation where methanogenic fermentation stops, the methanogenic fermentation of organic substances and the methanation of carbon dioxide in biogas can be made compatible, and the enlargement and complication of the device can be avoided.

[0011] A further characteristic configuration of the organic substance treatment device according to the present invention is that it is provided with fermentation liquid supply means for constantly or intermittently supplying the methanogenic fermentation liquid in the methanogenic fermentation tank to the carrier.

[0012] When the organic substance treatment device is continuously operated, when the methanogenic fermentation liquid impregnated in the carrier drops off or for some reason the activity of the methanogenic bacteria in the methanogenic fermentation liquid decreases, it may be necessary to supply the methanogenic fermentation liquid to the carrier. According to the above characteristic configuration, when the activity of the methanogenic bacteria in the methanogenic fermentation liquid impregnated in the carrier decreases or every time a certain period of time has elapsed since the start of the treatment, the methanogenic fermentation liquid can be supplied to the carrier. Therefore, continuous operation of the organic substance treatment device becomes possible without requiring an operation such as taking out the carrier from the methanogenic fermentation tank and impregnating it with the methanogenic fermentation liquid.

[0013] A further characteristic configuration of the organic substance treatment device according to the present invention is that it is provided with cleaning means for cleaning the carrier.

[0014] When the impregnation of the methanogenic fermentation liquid into the carrier or the supply of the methanogenic fermentation liquid by the fermentation liquid supply means is repeated, dirt accumulates on the surface of the carrier, the flow of gas (hydrogen and carbon dioxide) into the carrier is obstructed, and it may become difficult for the methanation of carbon dioxide by the methanogenic bacteria in the methanogenic fermentation liquid impregnated in the carrier to occur. However, according to the above characteristic configuration, since the carrier can be washed, the accumulation of dirt on the surface of the carrier can be suppressed, and the occurrence of a situation where it becomes difficult for the methanation of carbon dioxide by methanogenic bacteria to occur can be suppressed. Therefore, stable continuous operation of the organic matter treatment device becomes possible.

[0015] A further characteristic configuration of the organic matter treatment device according to the present invention is In the methanogenic fermentation tank, the methanogenic fermentation treatment is carried out with an organic matter load of 3 gCODcr / L / day or more.

[0016] The situation where methanogenic fermentation stops is likely to occur by blowing hydrogen into the methanogenic fermentation liquid when the methanogenic fermentation treatment is a treatment with a particularly high organic matter load (a large amount of methane generation). According to the above characteristic configuration, when performing the methanogenic fermentation treatment with a high organic matter load as described above, it is possible to avoid the occurrence of the situation where methanogenic fermentation stops and to methanate carbon dioxide in the biogas.

[0017] A further characteristic configuration of the organic matter treatment device according to the present invention is The organic matter is food waste.

[0018] According to the above characteristic configuration, when treating food waste, which is likely to have a relatively high organic matter load, it is possible to avoid the occurrence of the situation where methanogenic fermentation stops and to methanate carbon dioxide in the biogas.

[0019] A further characteristic configuration of the organic matter treatment device according to the present invention is Recovery means for recovering gas from the upper space in the methanogenic fermentation tank, Supplying the gas recovered by the recovery means together with the hydrogen supplied by the hydrogen supply means to the upper space.

[0020] According to the above characteristic configuration, the portion of the hydrogen supplied into the methane fermentation tank that is not used for methanation can be recovered from the upper space together with the biogas and supplied again to the upper space, so that the effective utilization of the unused hydrogen becomes possible.

[0021] A further characteristic configuration of the organic matter treatment apparatus according to the present invention is that the carrier is a fibrous carrier.

[0022] The inventor of the present application has experimentally confirmed that by using a fibrous carrier as the carrier, methanation of carbon dioxide occurs in the presence of hydrogen and carbon dioxide in a state where the carrier is impregnated with the methane fermentation liquid.

[0023] A further characteristic configuration of the organic matter treatment apparatus according to the present invention is that the fibrous carrier is a carbon fiber carrier.

[0024] The inventor of the present application has experimentally confirmed that by using a carbon fiber carrier as the fibrous carrier, the above-mentioned methanation of carbon dioxide occurs sufficiently.

Brief Description of the Drawings

[0025]

Figure 1

Figure 2

Figure 3

Figure 4

Embodiments for Carrying Out the Invention

[0026] Hereinafter, an organic matter treatment apparatus according to an embodiment of the present invention will be described with reference to the drawings. In the following, the case where the organic matter to be treated is food waste will be described as an example.

[0027] FIG. 1 is a diagram showing a schematic configuration of an organic matter treatment apparatus according to an embodiment. As shown in FIG. 1, the organic matter treatment apparatus includes a methane fermentation tank 10 to which food waste is supplied, a hydrogen supply unit 20 (hydrogen supply means) for supplying hydrogen into the methane fermentation tank 10, and a biogas recovery unit 30 (recovery means) for recovering biogas from the methane fermentation tank 10.

[0028] 〔Methane Fermentation Tank〕 As shown in FIG. 1, the methane fermentation tank 10 is composed of a housing and forms a methane fermentation space 11 for biodegradating food waste supplied from the outside of the housing by methane fermentation by methane bacteria. In this methane fermentation space 11, a heat exchanger (not shown) is provided to maintain the methane fermentation liquid in the methane fermentation space 11 at a favorable temperature (for example, 30 to 37 ° C, or 50 to 65 ° C) for good methane fermentation. In the present embodiment, in the methane fermentation space 11, a food waste supply port 15 for supplying food waste is provided so as to face the methane fermentation space 11 on one of the two opposing inner walls of the housing. Further, on the other of the two inner walls, a treated water discharge port 16 for discharging the treated water to the outside is also provided so as to face the methane fermentation space 11.

[0029] The upper space of the methane fermentation space 11 (the space above the liquid level of the methane fermentation liquid in the methane fermentation tank 10) constitutes a biogas collection space 12 for collecting biogas such as methane and carbon dioxide generated in the methane fermentation space 11.

[0030] In the biogas collection space 12, a net-like support member S is spanned between two opposing inner walls of the housing. A carrier T impregnated with the methanogenic fermentation liquid is placed on this support member S, and the carrier T is in a state where it does not contact the liquid surface of the methanogenic fermentation liquid in the methanogenic fermentation space 11, but there is no problem even if it contacts. In the present embodiment, the carrier T is a fiber carrier made of carbon fiber, but it is not particularly limited as long as it can hold the methanogenic fermentation liquid. For example, polyester, PVA, or acrylic resin can be adopted. In addition, the higher the bulk density of the carrier T, the higher the methanation rate of carbon dioxide (in other words, carbon dioxide can be efficiently converted into methane). Therefore, it is preferable to use a carrier T with a large bulk density within the range where the methanogenic fermentation liquid can be impregnated.

[0031] In addition, on the ceiling of the housing constituting the methanogenic fermentation tank 10 (above the biogas collection space 12), a first shower 40 (fermentation liquid supply means) for injecting the methanogenic fermentation liquid pumped up from the methanogenic fermentation space 11 onto the carrier T and a second shower 45 (cleaning means) for injecting a cleaning liquid (for example, water) for cleaning the carrier T onto the carrier T are installed.

[0032] The first shower 40 is configured such that the methanogenic fermentation liquid is pumped up from the methanogenic fermentation space 11 through the fermentation liquid supply path 41, and the fermentation liquid supply path 41 is provided with an on-off valve, a flow rate adjustment valve, etc. (not shown). In the present embodiment, the operations of these on-off valves and flow rate adjustment valves are configured to be controllable by a control device (not shown), and the injection amount and injection timing of the methanogenic fermentation liquid from the first shower 40 can be adjusted. Therefore, the first shower 40 can supply the methanogenic fermentation liquid in the methanogenic fermentation space 11 to the carrier T constantly or intermittently. In addition, the supply of the methanogenic fermentation liquid to the carrier T by the first shower 40 may be performed every time a predetermined time has elapsed since the start of the operation of the organic matter treatment device, or may be performed during the operation.

[0033] The second shower 45 is configured such that cleaning liquid is supplied from a cleaning liquid supply unit 47 via a cleaning liquid supply passage 46. An on-off valve and a flow rate adjustment valve (not shown) are provided in the cleaning liquid supply passage 46. In this embodiment, the operations of these on-off valve and flow rate adjustment valve are configured to be controllable by a control device (not shown), and the injection amount and injection timing of the cleaning liquid from the second shower 45 are adjustable. Note that it is preferable to perform the cleaning of the carrier T by the second shower 45 at the timing when the operation of the organic matter treatment device is stopped. The cleaning frequency depends on, for example, the degree of soiling of the carrier T, but is preferably about once a week, for example.

[0034] Note that when the microorganisms on the carrier T require trace elements to maintain their activity, methane fermentation liquid may be supplied as trace elements by the first shower 40, or a cleaning liquid containing trace elements such as iron, nickel, and cobalt may be supplied by the second shower 45.

[0035] In this embodiment, in the biogas collection space 12, a hydrogen supply port 23 for supplying hydrogen from a hydrogen supply unit 20 is provided facing the biogas collection space 12 on one of the two opposing inner walls of the housing. Also, a biogas outlet 33 for taking out biogas to the biogas recovery unit 30 is similarly provided facing the biogas collection space 12 on the other of the two inner walls.

[0036] In this embodiment, the hydrogen supply unit 20 is composed of a hydrogen cylinder 21 storing hydrogen, a hydrogen supply passage 22, a hydrogen supply port 23, etc., and the hydrogen in the hydrogen cylinder 21 is supplied into the biogas collection space 12 via the hydrogen supply passage 22 and the hydrogen supply port 23. In this embodiment, the operation of the on-off valve provided in the hydrogen cylinder 21 is configured to be controllable by a control device (not shown). Therefore, according to the hydrogen supply unit 20, hydrogen can be supplied into the biogas collection space 12 at an arbitrary supply amount and arbitrary timing. Note that the hydrogen supply unit 20 is not particularly limited as long as it is configured to be able to supply hydrogen into the biogas collection space 12. For example, a hydrogen production device may be employed instead of the hydrogen cylinder 21.

[0037] In this embodiment, a biogas recovery unit 30 is constituted by a tank 31 connected to a pump (not shown), a biogas extraction path 32, a biogas outlet 33, a circulation supply path 34, etc., and biogas is sucked from the inside of the biogas collection space 12 through the biogas outlet 33 and the biogas extraction path 32 and stored in the tank 31. Further, the biogas recovery unit 30 is configured to supply the biogas recovered in the tank 31 into the biogas collection space 12 together with hydrogen through a circulation supply path 34 connecting the tank 31 and the hydrogen supply path 22. In this embodiment, an on-off valve and a flow rate adjustment valve that can be operationally controlled by a control device (not shown) are provided in each of the biogas extraction path 32 and the circulation supply path 34. Therefore, according to the biogas recovery unit 30, biogas can be recovered from the inside of the biogas collection space 12 in an arbitrary extraction amount and at an arbitrary timing, and biogas can be supplied into the biogas collection space 12 through the circulation supply path 34 in an arbitrary supply amount and at an arbitrary timing. Note that the biogas recovery unit 30 is not particularly limited as long as it can recover biogas from the biogas collection space 12.

[0038] In the methane fermentation tank 10 having the above configuration, methane fermentation is carried out in the methane fermentation space 11, so that biogas is generated, and the generated biogas is collected in the biogas collection space 12. Then, by using the hydrogen supplied into the biogas collection space 12, carbon dioxide in the biogas in the biogas collection space 12 (in the space above the liquid level of the methane fermentation liquid) is methanated by methane bacteria in the methane fermentation liquid impregnated in the carrier T. That is, in this embodiment, without blowing hydrogen into the methane fermentation liquid in the methane fermentation space 11, while carrying out methane fermentation in the methane fermentation liquid in the methane fermentation space 11, carbon dioxide in the biogas generated by the methane fermentation can be methanated by methane bacteria held in the carrier T, and the occurrence of a situation where methane fermentation stops can be avoided within one methane fermentation tank 10, and carbon dioxide in the biogas can be methanated, and an increase in the size and complexity of the device can also be avoided.

[0039] Also, in the present embodiment, in the methane fermentation tank 10, methane fermentation for treating food waste is performed, and such methane fermentation is a treatment with a high organic matter load (a large amount of methane generation). In the methane fermentation treatment with a high organic matter load, a situation where methane fermentation stops easily occurs by blowing hydrogen into the methane fermentation liquid. That is, the organic matter treatment apparatus according to the present embodiment can be particularly preferably used when performing a methane fermentation treatment with a high organic matter load (more specifically, a methane fermentation treatment with an organic matter load of 3 gCODcr / L / day or more, preferably 5 gCODcr / L / day or more, more preferably 10 gCODcr / L / day or more) in the methane fermentation tank 10.

[0040] 〔Treatment Flow〕 Hereinafter, the process of treating food waste by the organic matter treatment apparatus having the above configuration will be described.

[0041] First, food waste is supplied to the methane fermentation tank 10, and the food waste supplied to the methane fermentation tank 10 is methane-fermented in the methane fermentation tank 10 to generate biogas, and the generated biogas is collected in the biogas collection space 12.

[0042] Here, hydrogen is supplied from the hydrogen supply unit 20 into the biogas collection space 12. Therefore, using the hydrogen supplied into this biogas collection space 12, methane bacteria in the methane fermentation liquid impregnated in the carrier T methanate carbon dioxide in the biogas in the biogas collection space 12.

[0043] On the other hand, the treated water generated by methane fermentation is discharged to the outside from the treated water discharge port 16.

[0044] As described above, according to the organic matter treatment apparatus according to the present embodiment, methane fermentation in the methane fermentation liquid and methanation of carbon dioxide in the biogas generated by methane fermentation can be performed without blowing hydrogen into the methane fermentation liquid in the methane fermentation space. Therefore, without adopting a two-tank type, it is possible to achieve both methane fermentation of organic matter and methanation of carbon dioxide in biogas while avoiding the occurrence of a situation where methane fermentation stops in one methane fermentation tank, and it is possible to avoid an increase in the size and complexity of the apparatus.

[0045] Hereinafter, examples and comparative examples will be shown.

[0046] 〔Example 1〕 A 3 cm carbon fiber carrier (Donacarb felt manufactured by Osaka Gas Chemical Co., Ltd.) impregnated with methane fermentation liquid for 24 hours was placed in a 120 ml vial simulating the space above the liquid level of the methane fermentation liquid in the methane fermentation tank (hereinafter also referred to as the gas phase space). Then, after replacing the gas in the vial with biogas generated from a separate food waste methane fermentation test apparatus, 100 ml of hydrogen gas was further added and heated at 55°C. When the gas volume in the vial after 24 hours was measured, 13.5 ml of hydrogen had been consumed. This corresponds to the amount required to methanate 3.4 ml of carbon dioxide. From this, it was confirmed that by placing the carrier impregnated with the methane fermentation liquid in the gas phase space, methanation of carbon dioxide in the gas phase space occurred. Also, when calculating the consumption rate of carbon dioxide per unit volume of the carrier, it was 0.047 ml / cm / hour. The general biogas generation rate of an apparatus for treating food waste is 2 ml / ml / day, and since 40% of the biogas is carbon dioxide, the generation rate of carbon dioxide is 0.033 ml / ml / hour. That is, it was also found that by installing a carrier having a volume similar to that of the methane fermentation liquid in the methane fermentation tank and impregnating the carrier with the methane fermentation liquid, most of the carbon dioxide in the biogas generated by methane fermentation can be methanated. 3

[0047] 〔Example 2〕 A 24-cm carbon fiber carrier impregnated with the methanogenic fermentation broth for 24 hours in a vial of the same type as that used in Example 1 was placed. 3 Subsequently, after replacing the gas in the vial with the above biogas, 100 ml of hydrogen gas was further added, and the mixture was heated at 55°C. The production rate of methane per hour in the vial, which increased between 18 hours and 24 hours after the start of heating, was 1.8 ml / h. On the other hand, after 24 hours, when the gas in the vial was completely replaced with fresh biogas and 100 ml of hydrogen was added and the same test was conducted, the methane production rate per hour was 4.6 ml. From this, it is inferred that the methanogenic bacteria once fixed on the carrier can be reused repeatedly, and the ability of the methanogenic bacteria on the carrier has been improved by self-proliferation while causing a methanation reaction on the carrier.

[0048] [Example 3] Using carbon fiber carriers with the impregnation time of the methanogenic fermentation broth changed to 10 minutes and 2 hours, tests were conducted in the same procedure as in Example 2. As a result, the methane generation amount did not increase for those with an impregnation time of 10 minutes and 2 hours. The amount of the methanogenic fermentation broth adhering to the carrier was 0.5 times that when the impregnation time was 24 hours for 10 minutes and 0.6 times for 2 hours. In both cases, although a certain amount of the methanogenic fermentation broth adhered, the methane generation amount decreased. Therefore, it is considered important for the methanation of carbon dioxide that methanogenic bacteria settle on the carrier. As can be seen from Example 2, once the methanogenic bacteria settle on the carrier, the activity of the methanogenic bacteria can be maintained and expanded thereafter, so it is not necessary to constantly supply the methanogenic fermentation broth to the carrier.

[0049] [Example 4] Figure 2 shows the relationship between the amount of carrier holding liquid and the methane acceleration rate obtained by conducting tests in the same procedure as in Example 2 using four types of carbon fiber carriers (bulk density: 9.5, 63, 100 kg / m 3 ). As can be seen from Figure 2, methane generation was confirmed for all carriers, but no correlation was found between the amount of carrier holding liquid and the methane acceleration rate. Further, the relationship between the bulk density and the methane production rate is shown in FIG. 3. As can be seen from FIG. 3, since the higher the bulk density of the carrier, the faster the methane production rate, it was confirmed that the weight per volume is important in order to effectively cause the methanation of carbon dioxide.

[0050] 〔Comparative Example 1〕 After replacing the gas in a vial of the same type as used in Example 1 with the above biogas, 100 ml of hydrogen gas was further added and heated at 55°C. When the gas volume in the vial after 24 hours was measured, no consumption of hydrogen was confirmed. From this, it was confirmed that when there is no carrier impregnated with the methanogenic liquid, the methanation of carbon dioxide in the gas phase space does not occur.

[0051] 〔Comparative Example 2〕 A certain amount of methanogenic liquid was placed in a vial of the same type as used in Example 1, the gas was replaced with biogas, 100 ml of hydrogen gas was further added, and heated at 55°C. When the gas volume in the vial after 24 hours was measured, no consumption of hydrogen in the gas phase space was confirmed. From this, it was confirmed that in order to cause the methanation of carbon dioxide in the gas phase space, a carrier impregnated with the methanogenic liquid is necessary.

[0052] 〔Another Embodiment〕 〔1〕In the above-described embodiment, the carrier T is arranged on the support member S, and the carrier T is positioned in the biogas collection space 12 above the methane fermentation space 11. However, the present invention is not limited to this. For example, as shown in FIG. 4, the carrier T may be arranged such that a part of it is immersed in the methane fermentation liquid in the methane fermentation space 11 and the remaining part is located in the space above the liquid level of the methane fermentation liquid. Even in this case, since a part of the carrier T is located on the liquid surface of the methane fermentation liquid, methane fermentation can be carried out in the methane fermentation liquid in the methane fermentation space 11 without blowing hydrogen into the methane fermentation liquid in the methane fermentation space 11, and carbon dioxide in the biogas in the biogas collection space 12 generated by the methane fermentation can be methanated by the methane bacteria held on the carrier T. Therefore, without adopting a two-tank type, it is possible to achieve both methane fermentation of organic substances and methanation of carbon dioxide in biogas while avoiding the occurrence of a situation where methane fermentation stops in a single methane fermentation tank, and it is also possible to avoid an increase in the size and complexity of the device.

[0053] 〔2〕In the above-described embodiment, the first shower 40 is provided as the fermentation liquid supply means. However, the present invention is not limited to this, and an embodiment without the fermentation liquid supply means may also be possible.

[0054] 〔3〕In the above-described embodiment, the second shower 45 is provided as the cleaning means. However, the present invention is not limited to this, and an embodiment without the cleaning means may also be possible.

[0055] 〔4〕In the above-described embodiment, the organic substance to be treated is food waste. However, the present invention is not limited to this, and the object to be treated may be other organic substances. Further, the organic substance may be subjected to pretreatment such as crushing or solubilization.

[0056] 〔5〕In the above-described embodiment, the biogas recovery unit 30 is provided as the recovery means, and the biogas recovered from the biogas collection space 12 is supplied again to the biogas collection space 12 to circulate the biogas. However, the present invention is not limited to this. For example, the biogas recovered by the biogas recovery unit 30 may be stored in the tank without being circulated.

[0057] The configurations disclosed in the above-described embodiment (including other embodiments) can be applied in combination with the configurations disclosed in other embodiments as long as there is no contradiction. In addition, the embodiments disclosed in this specification are illustrative, and the embodiments of the present invention are not limited thereto, and can be appropriately modified within the scope not departing from the object of the present invention.

Industrial Applicability

[0058] The present invention can be used in an organic matter treatment apparatus that treats organic matter using methane fermentation.

Explanation of Reference Numerals

[0059] 1: Organic matter treatment apparatus 10: Methane fermentation tank 12: Biogas collection space (space above the liquid level of the methane fermentation liquid) 20: Hydrogen supply unit (hydrogen supply means) 30: Biogas recovery unit (recovery means) 40: First shower (fermentation liquid supply means) 45: Second shower (cleaning means) T: Carrier

Claims

1. An organic matter treatment apparatus comprising a methane fermentation tank to which organic matter is supplied, a carrier disposed in the methane fermentation tank in a state where a part thereof is immersed in the methane fermentation liquid in the methane fermentation tank and the remaining part is located in a space above the liquid level of the methane fermentation liquid, or in a state where it is located in a space above the liquid level of the methane fermentation liquid, and impregnated with the methane fermentation liquid, and a hydrogen supply means for supplying hydrogen to the above space.

2. The organic matter treatment apparatus according to claim 1, further comprising a fermentation liquid supply means for constantly or intermittently supplying the methane fermentation liquid in the methane fermentation tank to the carrier.

3. The organic matter treatment apparatus according to claim 1 or 2, further comprising a cleaning means for cleaning the carrier.

4. In the methane fermentation tank, the organic matter treatment apparatus according to any one of claims 1 to 3, wherein methane fermentation treatment is performed with an organic matter load of 3 g CODcr / L / day or more.

5. The organic matter treatment apparatus according to any one of claims 1 to 4, wherein the organic matter is food waste.

6. a recovery means for recovering gas from the above space in the methane fermentation tank, and The organic matter treatment apparatus according to any one of claims 1 to 5, wherein the gas recovered by the recovery means is supplied to the above space together with hydrogen supplied by the hydrogen supply means.

7. The organic matter treatment apparatus according to any one of claims 1 to 6, wherein the carrier is a fiber carrier.

8. The organic matter treatment apparatus according to claim 7, wherein the fiber carrier is a carbon fiber carrier.

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