JPH11149933A - Fuel cell plant fueled with fermentation gas of organic waste - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fuel cell plant fueled with fermentation gas of organic wastes capable of continuously and stably operating fuel cells for a long duration by adjusting the quantity of power generation of the fuel cells corresponding to the amount of the collected organic wastes. SOLUTION: A sludge sensor 2 for detecting the amount of sludge A is installed in a storage tank 1. A totalizing part 9 for computing the production amount of a bio-gas B based on the detected value of the sludge sensor 2 is installed in the sludge sensor 2. An indicating part 10 for indicating the optimum power generation quantity calculated from the production amount of the bio-gas B to a fuel cell main body 7 corresponding to the production amount of the bio-gas B computed by the totalizing part 9 is further connected with the totalizing part 9.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel cell plant utilizing a fermentation gas generated from organic waste as a fuel gas, and more particularly, to a stable continuous operation by monitoring an amount of organic matter supplied to the plant. The present invention relates to a fuel cell plant that uses an organic waste fermentation gas.

[0002]

2. Description of the Related Art Generally, in the field of treating organic wastes such as sewage and human waste, or garbage and food wastewater, these organic substances are discarded by incineration or dehydration. However, in today's world, where environmental protection has been taken up on a global scale, incineration and dehydration have each had serious problems. That is, in the incineration treatment, carbon dioxide gas and dioxin are emitted, which may promote global warming and air pollution. Also,
In the dehydration treatment, there was a concern that dehydration would contaminate the groundwater.

[0003] Digestion, which adds bacteria to organic waste and decomposes it, has attracted attention. If organic waste is decomposed by adding bacteria, there is no risk of air pollution or groundwater pollution, and excellent environmental harmony can be exhibited. One type of such digestion treatment is anaerobic digestion treatment using anaerobic bacteria in a state where air is shut off. Anaerobic digestion generates secondary fermentation gas when organic waste is decomposed. Since this fermentation gas contains 60 to 70% of methane gas, it is also called methane fermentation.

[0004] Fermentation gas in anaerobic digestion is usually
As organic waste 1kg per 0.4～0.7M ³ occurs, owns a very high heat of 5000~7500kcal / m ^3. Therefore, it has been considered that this fermentation gas is recovered as heat energy and used as an energy source for gas engines and fuel cells.

[0005] A fuel cell is a device that directly converts chemical energy held by fuel into electric energy, and is attracting attention as a clean power generation device that does not cause air pollution. Therefore, utilizing fermentation gas by-produced in waste treatment as an energy source for fuel cells
It is very effective from the viewpoint of environmental protection and recycling.

In addition, a fuel cell plant using a fuel cell can employ not only a power generation system, but also a cogeneration system that takes out and uses waste heat from the fuel cell generated during power generation. Therefore, it is possible to raise the activation temperature of the anaerobic bacteria by using the exhaust heat from the fuel cell, and to increase the processing capacity of the organic waste. As described above, the fuel cell plant and the anaerobic digestion treatment facility can have good compatibility. Therefore, in recent years, the practical use of a fuel cell plant using fermentation gas of organic waste using fermentation gas as fuel gas for a fuel cell has been considered.

[0007]

However, realizing a fuel cell plant using organic waste fermentation gas has the following problems.

That is, in order to use fermentation gas as fuel gas for a fuel cell, it is necessary to constantly collect a predetermined amount or more of organic wastes, which are sources of fermentation gas.
However, in the field of organic waste treatment, stable collection of organic waste was difficult except in the sewage treatment field where continuous treatment was possible due to the spread of sewerage.

[0009] That is, in the human waste processing field and the garbage processing field, collection of human waste and garbage is still performed by a collection vehicle. Therefore, organic waste can be secured only on the collection day, and the amount of organic waste collected is not constant. Also, in the food wastewater treatment field, when a food factory stops operating, such as on a holiday, the wastewater from the factory also stops, so that organic waste cannot be secured in a stable manner.

[0010] As described above, the amount of collected organic waste was unstable as it varied from day to day. Therefore, when the amount of collected organic waste is small and the production amount of the fermentation gas falls below the amount required for operating the fuel cell main body, the fuel cell main body must be stopped. Unless such operation instability of the fuel cell body is eliminated, it has been difficult to stably and continuously operate a fuel cell plant using fermentation gas of organic waste over a long period of time.

When a large amount of organic waste is collected and the amount of fermentation gas supplied to the fuel cell main body exceeds the amount required for operation of the fuel cell main body, the fermentation gas is not supplied to the fuel cell main body. Gas will be supplied in excess, and such excess fermentation gas will be discharged outside the plant. As a result, the environment surrounding the plant was affected.

Further, a transfer pump for supplying the fermentation gas to the fuel cell body is indispensable for the fuel cell plant using the fermentation gas of the organic waste, and this transfer pump reduces the production amount of the fermentation gas. Regardless, they generally demonstrate a certain supply capacity. Therefore, even if the amount of organic waste collected is small and the amount of fermented gas produced is small,
The same level of supply capacity as in the case of a large amount of fermented gas production was exhibited, the running cost was high, and it was economically disadvantageous.

When collecting organic waste, it is needless to say that it is desirable to immediately and accurately determine the amount of the collected organic waste. Therefore, it is required that the fuel cell plant be provided with an excellent tallying unit for the collection amount.

Further, even if organic waste is collected, not only organic waste effective for generating fermentation gas is not always collected. Particularly, in the field of garbage disposal, organic waste is not collected. In some cases, components that inhibit the production of fermentation gas and components that are harmful in the production of fermentation gas and the operation of the fuel cell were included. Therefore, unless the components in the collected organic waste were confirmed, the organic waste could not be used as a safe energy source.

Furthermore, at present, when the demand for the treatment of organic waste is severe, the amount of collected organic waste is at least extremely small, and the fuel from the fermentation gas of organic waste can be used sufficiently. The battery plant was waiting.

The present invention has been proposed in view of the above situation, and its main purpose is to adjust the power generation amount of a fuel cell in accordance with the amount of collected organic waste for a long time. An object of the present invention is to provide a fuel cell plant using fermentation gas of organic waste, which can realize stable continuous operation of a fuel cell.

Another object of the present invention is to adjust the supply of fermentation gas in accordance with the amount of collected organic waste, thereby reducing running costs and improving economic efficiency.
It is another object of the present invention to provide a fuel cell plant using organic waste fermentation gas, which can suppress the release of excess fermentation gas and contribute to maintaining the environment near the plant.

Still another object of the present invention is to provide a fuel cell plant using an organic waste fermentation gas, which is provided with an excellent counting unit so that the amount of collected organic waste can be immediately and accurately grasped. To provide.

Another object of the present invention is to provide a fuel cell plant using fermented organic waste gas which can continue safe operation by detecting harmful components in the collected organic waste. Is to do.

Still another object of the present invention is to provide a fuel cell plant using an organic waste fermentation gas, which can sufficiently utilize an organic waste even if the amount is very small. It is in.

[0021]

In order to achieve the above object, the invention of claim 1 provides a fuel cell body using fermentation gas generated from organic waste as fuel, and storing the organic waste. A storage tank, an organic waste provided with a fermentation gas producing apparatus for producing the fermentation gas by taking in the organic waste from the storage tank, and a transfer pump for supplying the fermentation gas to the fuel cell body In a fuel cell plant using fermentation gas, an organic substance sensor for detecting an amount of the organic waste in the storage tank is installed in the storage tank, and the organic substance sensor detects a detection value from the organic substance sensor. A tallying unit for inputting and calculating the production amount of the fermentation gas based on the detection value is connected, and the tallying unit is connected to the fuel cell main body according to the production amount of the fermentation gas calculated by the tallying unit. It is characterized in that the power generation amount instruction section for instructing the power generation is connected for.

In the first aspect of the present invention having the above configuration, the organic substance amount sensor detects the amount of organic waste in the storage tank and sends the detected value to the counting section. The tallying unit inputs a detection value from the organic substance amount sensor, and calculates a production amount of the fermentation gas based on the detection value. Then, the power generation amount instructing unit instructs the fuel cell body on the amount of power generation according to the fermentation gas production amount calculated by the tallying unit.

According to the first aspect of the present invention, when the amount of organic waste collected in the storage tank is small,
It is possible to make an adjustment so as to keep the power generation amount of the fuel cell main body low by an instruction from the power generation amount instruction section. Therefore, it is not necessary to stop the fuel cell body at least when the amount of organic waste is present, and the fuel cell plant using the fermentation gas of organic waste can be operated continuously for a long period of time.

According to a second aspect of the present invention, there is provided a fuel cell body using fermentation gas generated from organic waste as a fuel, a storage tank for storing organic waste, and taking in the organic waste from the storage tank. A fermentation gas production apparatus for producing the fermentation gas at, and a transfer pump for supplying the fermentation gas to the fuel cell body, a fuel cell plant using organic waste fermentation gas, wherein the storage tank includes An organic substance sensor for detecting the amount of the organic waste in the storage tank is provided, and the organic substance sensor inputs a detection value from the organic substance sensor and calculates the production amount of the fermentation gas based on the detected value. A tallying unit for calculation is connected, and the tallying unit is configured to instruct the transfer pump to supply a fermentation gas supply amount according to the fermentation gas production amount calculated by the tallying unit. Radical 113 wherein the is connected.

According to the second aspect of the present invention having the above-described structure, the organic substance amount sensor detects the amount of organic waste in the storage tank and sends the detected value to the counting section. The tallying unit inputs the detected value, and calculates the production amount of the fermentation gas based on the detected value. Then, the fermentation gas supply amount instructing unit instructs the transfer pump on the fermentation gas supply amount according to the fermentation gas production amount calculated by the tallying unit.

According to the second aspect of the present invention, the supply capacity of the transfer pump can be adjusted according to the amount of fermentation gas produced by the instruction of the fermentation gas supply amount instruction section.
Therefore, when the amount of organic waste collected in the storage tank is small and the production amount of fermentation gas is small, the supply amount of fermentation gas can be kept low, and the running cost of the transfer pump can be reduced. it can. Moreover, since the supply amount of the fermentation gas can be adjusted, the fermentation gas is not excessively supplied to the fuel cell main body, and the fermentation gas is not released outside the plant. Therefore, the environment near the plant can be favorably maintained.

According to a third aspect of the present invention, in the fuel cell plant using the organic waste fermentation gas according to the first or second aspect, a deviation between a previous value detected by the counting unit a predetermined time ago and a current value is calculated. It is characterized by having been constituted so that.

According to the third aspect of the present invention having the above-described configuration, the totaling unit calculates a deviation from the previous value detected a predetermined time ago. And accurately.

The invention of claim 4 is the invention of claim 1, 2 or 3.
In the fuel cell plant using the organic waste fermentation gas described above, the organic substance sensor is harmful in the production of the fermentation gas and the operation of the fuel cell main body from the organic waste in the storage tank. It is characterized in that it is configured to detect the component amount.

According to the fourth aspect of the present invention having the above-described structure, the organic substance amount sensor can detect the amount of harmful components from the organic waste in the storage tank, so that the fuel cell body and the fermentation gas production can be detected. Deterioration or breakage of the performance of the device or the transfer pump can be avoided, and excellent safety can be ensured.

According to a fifth aspect of the present invention, in the fuel cell plant according to the first, second, third or fourth aspect of the present invention, a reserve fuel tank for storing reserve fuel is provided, and Reserve fuel supply control means for supplying the reserve fuel from the reserve fuel tank to the fuel cell body when a production amount of the fermentation gas produced by the device is smaller than an amount required for operation of the fuel cell body. Is provided.

According to the fifth aspect of the present invention having the above configuration, when the production amount of the fermentation gas produced by the fermentation gas production apparatus becomes smaller than the amount required for operating the fuel cell main body, the spare fuel supply is performed. The control means can supply the reserve fuel from the reserve fuel tank to the fuel cell body. Therefore, even if the collected organic waste is extremely small,
You can make the most of this.

According to a sixth aspect of the present invention, in the fuel cell plant using the organic waste fermentation gas according to the first, second, third, or fourth aspect, a spare fuel tank for storing spare fuel is provided, and the inside of the storage tank is provided. When the amount of harmful components contained in the organic waste in the production of the fermentation gas or the operation of the fuel cell main body exceeds a predetermined allowable value, the spare fuel tank transfers the fuel cell main body to the fuel cell main body. A reserve fuel supply control means for supplying reserve fuel is provided.

According to the sixth aspect of the present invention having the above structure, the amount of harmful components contained in the organic waste in the storage tank in the production of the fermentation gas and the operation of the fuel cell main body is set to the predetermined allowable value. When the number of fuel cells exceeds the limit, the reserve fuel supply control means can supply reserve fuel from the reserve fuel tank to the fuel cell body. Therefore, similarly to the invention of the fourth aspect, it is possible to avoid performance deterioration or breakage of the fuel cell main body, the fermentation gas production device or the transfer pump, and it is possible to perform continuous operation while ensuring excellent safety. it can.

[0035]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, an embodiment of a fuel cell plant using an organic waste fermentation gas according to the present invention will be specifically described with reference to FIG. This embodiment includes the first to sixth aspects of the present invention.

(1) Configuration [Overall Configuration] In the fuel cell plant of the present embodiment, a storage tank 1 for storing organic waste (hereinafter, referred to as sludge) A, and a sludge from the storage tank 1 A gas fermentation tank 5 that takes in A to produce a fermentation gas (hereinafter referred to as biogas B) and a fuel cell body 7 that uses the biogas B produced by the gas fermentation tank 5 as a fuel gas are provided. Have been. The in-cell controller 8 for controlling the operating state of the fuel cell body 7 is incorporated in the fuel cell body 7.

Further, between the storage tank 1 and the gas fermentation tank 5, a transfer pump 3 for supplying biogas B to the fuel cell main body 7 and a sludge supply cutoff valve 4 are arranged. Further, a gas holder 6 for storing biogas B is disposed between the gas fermentation tank 5 and the fuel cell main body 7. The gas holder 6 is provided with a reserve fuel tank 12 for storing reserve fuel such as hydrogen via a reserve fuel supply cutoff valve 11. The reserve fuel supply cutoff valve 11 constitutes reserve fuel supply control means, and is configured to receive an instruction from an instruction unit 10 described later.

The configuration of this embodiment is characterized in that the storage tank 1 is provided with a sludge sensor 2, and the sludge sensor 2 is connected with a counting unit 9 and an instruction unit 10. The sludge sensor 2 is an organic matter amount sensor described in the claims, and the indicating unit 10 is a power generation amount indicating unit described in claim 1 and a fermentation gas supply described in claims 2 and 3. It also serves as a quantity indicating unit.

[Sludge sensor] The sludge sensor 2 is a bio-
From the sludge A in the storage tank 1, the effective component concentration effective in the generation of the gas B and the concentration of the harmful components of salts, fluorines, and silicons which are harmful in the generation of the biogas B and the operation of the fuel cell body 7 are determined. It is configured to detect. Specific examples of the configuration of the sludge sensor 2 include a sensor including a BOD meter for measuring the amount of organic substances and an individual analyzer for measuring the concentration of each harmful component such as salts, fluorines, and silicons.

[Tallying Unit] The tallying unit 9 incorporates a circuit for evaluating and calculating the concentration of the active ingredient and the concentration of the harmful ingredient detected by the sludge sensor 2. The counting unit 9 calculates the biogas B generated from the methane fermentation tank 5 based on the active ingredient concentration.
And the optimum power generation amount of the fuel cell main body 7 derived from the production amount. Regarding the evaluation of the concentration of harmful components, the counting unit 9 calculates the integrated value of the concentration of harmful components such as salts, fluorines, and silicon detected by the sludge sensor 2 and determines each component as an instantaneous value and an integrated value. It is configured to determine whether the value is exceeded. Further, the tallying unit 9 is configured to calculate a deviation between a previous value detected a predetermined time before and a current value. Then, the counting unit 9 transmits the calculated physical quantity to the instruction unit 10.

[Instruction Unit] The instruction unit 10 includes the transfer pump 3,
The sludge supply cutoff valve 4, the control unit 8 in the battery, and the reserve fuel supply cutoff valve 11 are connected. The instruction unit 10 is configured to instruct the operation control of the transfer pump 3, the sludge supply cutoff valve 4, and the reserve fuel supply cutoff valve 11, and the load adjustment of the control unit 8 in the battery.

When the sludge center 2 transmits the physical quantities already detected and compiled by the tallying unit 9 to the instruction unit 10, the instruction unit 10
Performs the following operation. First, the tallying unit 9 is the instruction unit
When the production amount of biogas B is transmitted to 0, the indicator 10
Is transferred to the transfer pump 3 based on this physical quantity.
Is indicated. When the totalizing unit 9 transmits the optimum power generation amount of the fuel cell main body 7 derived from the production amount of the biogas B to the instruction unit 10, the instruction unit 10 determines whether the fuel cell main body 7 The fuel cell control unit 8 is instructed to set a load so as to generate a large amount of power.

Further, since the counting section 9 transmits the physical quantity to the indicating section 10 based on the difference between the previous value and the present value, the indicating section 10 determines whether there is a supply of new sludge A to the storage tank 1 based on the difference. Judge. When the current value is smaller than the previous value, the supply amount of the transfer pump 3 is instructed so as to reduce the supply amount of the biogas B, and the fuel cell is controlled so as to reduce the power generation amount of the fuel cell body 7. A load setting instruction is issued to the control unit 8. Conversely, when the current value is larger than the previous value, the supply amount of the transfer pump 3 is instructed so as to increase the supply amount of the biogas B, and the fuel amount is increased so that the power generation amount of the fuel cell body 7 is increased. A load setting instruction is issued to the battery control unit 8.

By the way, in the course of the above operation, the counting section 9
When the production amount of the biogas B calculated in the step is smaller than the minimum amount necessary for the power generation of the fuel cell main body 7, the instruction unit 10 stops the transfer pump 3 and turns off the sludge supply cutoff valve 4. Then, the supply of the biogas B to the gas fermentation tank 5 is stopped, and the production of the biogas B is stopped. Then, the spare fuel supply cutoff valve 11 is opened. As a result, the spare fuel tank 12 sends the spare fuel to the fuel cell main body 7, and the fuel cell main body 7 continues to operate with the spare fuel.

Also, when the counting section 9 determines that each harmful component such as salts, fluorines and silicon exceeds the permissible value in the instantaneous value and the integrated value, the indicating section 10 performs the same operation as in the upper case. Then, the transfer pump 3 is stopped, the sludge supply cutoff valve 4 is closed, the supply of the biogas B to the gas fermentation tank 5 is stopped, and the production of the biogas B is stopped. Then, the spare fuel supply cutoff valve 11 is opened. As a result, the spare fuel tank 12 sends the spare fuel to the fuel cell main body 7, and the fuel cell main body 7 continues to operate with the spare fuel.

(2) Operation and Effect The operation and effect of the present embodiment as described above are as follows. That is, when the sludge sensor 2 detects that the amount of the sludge A collected in the storage tank 1 is small, the counting unit 9 transmits the detection result to the instructing unit 10, and the instructing unit 10 calculates the power generation amount of the fuel cell main body 7. At the same time, the supply capacity of the transfer pump 3 can be kept low. Therefore, it is not necessary to stop the fuel cell body 7 at least when the amount of collected sludge A is stopped, and the fuel cell power generation plant using the organic waste fermentation gas can be operated continuously for a long time.

When the amount of collected sludge A is small, the supply capacity of the transfer pump 3 is reduced, so that the running cost of the transfer pump 3 can be reduced, which is economically advantageous. In addition, since the supply amount of the bio gas B can be adjusted, the excessive supply of the bio gas B to the fuel cell body 7 can be prevented,
There is no risk of affecting the environment near the plant due to the release of biogas B.

Moreover, since the counting section 9 calculates the deviation between the previous value and the current value detected a predetermined time ago, the instruction section 10 immediately and accurately determines a new collection amount of the sludge A from this deviation. It is possible to Furthermore, in the present embodiment, since the single instruction unit 10 plays the role of the power generation amount instruction unit and the fermentation gas supply amount instruction unit, the configuration can be simplified.

Further, in this embodiment, the sludge sensor 2
Does not simply detect the total amount of collected sludge A, but detects the effective component concentration effective for biogas B production. Therefore, even if the collected sludge A contains a component that suppresses the production of biogas B, accurate data can be sent to the tallying unit 9 that calculates the production amount of biogas B. .

Further, since the sludge sensor 2 detects harmful components such as salts, fluorines, and silicon from the sludge A in the storage tank 1 for each component, the counting unit 9 determines
When it is determined that the harmful components such as fluorines and silicons exceed the allowable values in the instantaneous value and the integrated value, the production of the biogas B and the supply to the fuel cell body 7 are stopped. As a result, performance deterioration and breakage of the fuel cell main body 7, the gas fermentation tank 5, and the transfer pump 3 can be prevented, and excellent safety can be secured.

When the production of the biogas B and the supply to the fuel cell body 7 are stopped, the reserve fuel supply shut-off valve 11 is opened to supply the reserve fuel from the reserve fuel tank 12 to the fuel cell body 7. be able to. Such a supply of the reserve fuel can also be performed when the amount of fermentation gas produced in the gas fermentation tank 5 becomes smaller than the amount required for operating the fuel cell main body 7. Therefore, even if the amount of collected sludge A is extremely small, it can be used to the maximum extent, and stable continuous operation can be performed over a long period of time.

(3) Other Embodiments The present invention is not limited to the above-described embodiments. For example, the power generation amount indicating unit and the fermentation gas supply amount indicating unit may be independently provided. May be provided. In addition, the specific configuration and installation location of the organic substance amount sensor, and the circuit configuration of the counting section can be appropriately changed.

[0053]

As described above, according to the fuel cell power plant using the organic waste fermentation gas of the present invention, the power generation amount of the fuel cell is adjusted according to the amount of collected organic waste. The stable continuous operation of the fuel cell can be realized for a long time, and the long-term reliability of the plant is improved.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an embodiment according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Storage tank 2 ... Sludge sensor 3 ... Transfer pump 4 ... Sludge supply cutoff valve 5 ... Methane fermentation tank 6 ... Gas holder 7 ... Fuel cell main body 8 ... Fuel cell control part 9 ... Total part 10 ... Instruction part 11 ... Spare fuel Supply cut-off valve 12: Reserve fuel tank A: Sludge B: Biogas

Claims (6)

[Claims] 1. A fuel cell body using fermentation gas generated from organic waste as a fuel, a storage tank for storing organic waste, and taking in the organic waste from the storage tank to produce the fermentation gas. In a fuel cell plant using fermentation gas of organic waste, comprising a fermentation gas production device to be manufactured and a transfer pump for supplying the fermentation gas to the fuel cell body, the storage tank includes the storage tank in the storage tank. An organic substance amount sensor for detecting the amount of organic waste is installed, and the tally unit that inputs a detection value from the organic substance quantity sensor to the organic substance quantity sensor and calculates the production amount of the fermentation gas based on the detected value is provided. A power generation amount instructing unit that instructs the fuel cell body to generate power in accordance with the production amount of the fermentation gas calculated by the aggregation unit. Fuel cell plant using organic waste fermentation gas. 2. A fuel cell body using fermentation gas generated from organic waste as a fuel, a storage tank for storing organic waste, and taking in the organic waste from the storage tank to produce the fermentation gas. In a fuel cell plant using fermentation gas of organic waste, comprising a fermentation gas production device to be manufactured and a transfer pump for supplying the fermentation gas to the fuel cell body, the storage tank includes the storage tank in the storage tank. An organic substance amount sensor for detecting the amount of organic waste is installed, and the tally unit that inputs a detection value from the organic substance quantity sensor to the organic substance quantity sensor and calculates the production amount of the fermentation gas based on the detected value is provided. A fermentation gas supply amount instructing unit that instructs the transfer pump to supply a fermentation gas supply amount according to the production amount of the fermentation gas calculated by the aggregation unit; A fuel cell plant using organic waste fermentation gas. 3. The organic waste fermentation gas according to claim 1, wherein the totalizing unit is configured to calculate a deviation between a previous value detected a predetermined time ago and a current value. By fuel cell plant. 4. The organic matter amount sensor is configured to detect, from the organic waste in the storage tank, an amount of a component that is harmful in producing the fermentation gas or operating the fuel cell main body. 4. The fuel cell plant according to claim 1, wherein the organic waste is a fermentation gas. 5. A reserve fuel tank for storing reserve fuel is provided, and when a production amount of the fermentation gas produced by the fermentation gas production device is smaller than an amount required for operation of the fuel cell main body, 5. A fuel according to claim 1, 2, 3 or 4, wherein a reserve fuel supply control means for supplying the reserve fuel from the reserve fuel tank to the fuel cell body is provided. Battery plant. 6. A reserve fuel tank for storing reserve fuel is provided, and the amount of harmful components contained in the organic waste in the storage tank in the production of the fermentation gas and the operation of the fuel cell main body is reduced. 5. A spare fuel supply control means for supplying the spare fuel from the spare fuel tank to the fuel cell body when a predetermined allowable value is exceeded, is provided. Fuel cell plant using organic waste fermentation gas.