JP2021116294A - Effective utilization system of recovered carbon dioxide, utilization method of recovered carbon dioxide, control method of effective utilization system of recovered carbon dioxide, and display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an effective utilization system of recovered carbon dioxide. SOLUTION: A carbon dioxide separation and recovery facility 6 and 7 for separating and recovering carbon dioxide from a gas containing carbon dioxide, a renewable energy power generation facility 11, and hydrogen obtained by electrolyzing water to generate hydrogen. A system including a water electrolysis facility 12 and a metanation facility having metanation reactors 19a to 19a to generate methane using carbon dioxide and hydrogen, and stores hydrogen produced by the water electrolysis facility. The hydrogen storage means 15 and the carbon dioxide storage means 9 for storing the carbon dioxide recovered by the carbon dioxide separation and recovery facility are further provided, and the hydrogen filling rate in the hydrogen storage means and the carbon dioxide filling rate in the carbon dioxide storage means can be determined. Recovered carbon dioxide having a configuration adjusted so as to be within a predetermined range and to supply hydrogen and carbon dioxide to the metanation reactor when the filling rate of hydrogen and carbon dioxide is equal to or higher than a predetermined value. Effective utilization system. [Selection diagram] Fig. 1

Description

The present invention relates to an effective utilization system of recovered carbon dioxide, a method of utilizing recovered carbon dioxide, a control method of an effective utilization system of recovered carbon dioxide, and a display device.

In recent years, from the viewpoint of preventing global warming, a technology for recovering _{CO 2} has been developed in order to reduce the emission _{of carbon dioxide (hereinafter referred to as "CO 2") from various industrial fields.} Further, _{a technique for converting the recovered CO 2} into an available energy source has been developed. A typical example is methane (hereinafter _{referred to as "CH 4} "). CH ₄ can be obtained from the recovered CO ₂ and hydrogen (hereinafter _{referred to as “H 2} ”) by the reaction represented by the following reaction formula (1).

CO ₂ + 4H ₂ → CH ₄ + 2H ₂ O… Reaction equation (1)
_{H 2} required for this reaction can be produced by the reaction represented by the following reaction formula (2) using electricity obtained from renewable energy represented by wind power or sunlight, for example. can.

2H ₂ O → 2H ₂ + O ₂ … Reaction equation (2)
In recent years, the introduction of renewable energy has been increasing rapidly, and depending on the day and time, it is predicted that the power supply will be excessive, and the acceptance of renewable energy will be stopped. In that case, the renewable energy power generator is forcibly stopped. If the renewable energy power generator is operated while it is forcibly stopped, the generated power becomes surplus power, and in order to effectively utilize the surplus power, _{development to manufacture H 2} is being actively carried out. .. Further, development is also being carried out in which _{CH 4} is produced by the reaction represented by the above reaction formula (1) using the produced H _{2 and CO 2} recovered from various industrial fields.

In the reaction represented by the above reaction formula (1), H ₂ and CO ₂ are supplied to a reactor containing a catalyst or a methane synthesizing bacterium to generate _{CH 4} and 2 H _{2 O.} In order to stably _{generate CH 4} , a stable _{supply of H 2} and CO ₂ is preferable.

However, when H ₂ is generated by electric power derived from renewable energy, the amount of power generation fluctuates greatly depending on the weather conditions, and the flow rate of _{H 2 generated accordingly also fluctuates greatly.} Also, the load fluctuation of the equipment for discharging the CO _2, the flow rate of CO ₂ to be recovered varies.

Therefore, when combined technique of generating of H ₂ from renewable energy, a technique for recovering CO ₂ from the facility for discharging CO _2, and CH ₄ and manufacturing technology (hereinafter referred to as "methanation".) Is, It is desirable to suppress fluctuations in the H ₂ flow rate and the CO _{2 flow rate, and to supply each of the H 2} and CO _{2 to} the methanation facility in a stable manner, in other words, at a constant flow rate as much as possible. This is because the flow rate of the generated CH ₄ can be made stable, that is, as constant as possible.

Patent Document 1 describes _{a technique for supplying high-pressure supercritical CO 2} to a combustor at a constant pressure in a thermal power generation system using a combustor that burns by adding oxygen and fuel using _{supercritical CO 2 as a working fluid, and renewable energy.} The unstable power of the above is produced and stored in hydrogen, methane and oxygen, and the supercritical CO ₂ turbine is rotated by using the methane produced by the power of renewable energy as fuel, and the emitted CO ₂ is generated again as methane. A completely closed closed cycle power generation system that does not emit _{CO 2 at all is disclosed.}

In Patent Document 2, a metanation reaction step is configured in multiple stages for the purpose of solving the problem that the amount of gas fluctuates due to fluctuations in the output of renewable energy when H2 generated by water electrolysis from renewable energy is used. A methane production method is disclosed in which a bypass step connecting the inlet of the first reaction step and the inlet of the subsequent reaction step is provided, and the flow rate of the reaction step and the bypass step is controlled so that each reaction step is in an equilibrium state.

In Patent Document 3, hydrogen is produced from the surplus energy on the distributed power source side that utilizes the renewable energy generated when the system is separated or the output is controlled, and methane is produced by the hydrogen and carbon dioxide recovered in the operation system. A system for producing methane is disclosed in which the produced methane is injected into a city gas conduit after adjusting the calorific value. Further, Patent Document 3 discloses a specific example of a catalyst used for producing methane.

Japanese Unexamined Patent Publication No. 2014-148934 Japanese Unexamined Patent Publication No. 2018-135283 Japanese Unexamined Patent Publication No. 2009-077457

Patent Document 1 describes that high-pressure supercritical CO _{2 to the combustor in the supercritical CO 2-} cycle power generation method is supplied to the combustor at a constant pressure and methane is produced using _{surplus CO 2.} be. However, the load fluctuation of upstream equipment that generates _{CO 2 is not fully considered.}

Patent Document 2 describes that the amount of CO2 supplied is controlled according to the flow rate of H2 generated by the electrolysis step of water using electricity obtained from fluctuating renewable energy. In the methanation reaction step, it is preferable to keep the flow rate ratio of _{H 2} and CO _{2 supplied constant, so it is desirable to control the H 2} flow rate as well. However, in Patent Document 2, it is considered that there is room for improvement in the case where _{H 2} is supplied in excess of the allowable supply amount of the metanation reactor.

The distributed power source operating system described in Patent Document 3 operates a distributed power source, which is a power source other than the system power provided for the purpose of stable operation of the system power, in a state where the environmental load is small, and the power demand is high. The produced hydrocarbon fuel is injected into the city gas grid system with the aim of reducing equipment costs by omitting storage facilities for methane produced when it is low. Therefore, it is not necessary to consider fluctuations in the hydrogen production rate due to fluctuations in renewable energy, in other words, fluctuations in the flow rate of hydrogen production, and it is not necessary to stabilize the flow rate of methane produced and to keep the flow rate constant. it is conceivable that.

An object of the present invention is that when the recovered carbon dioxide is effectively used, the generated power generated by the fluctuating renewable energy, the flow rate of the generated hydrogen fluctuating accordingly, and the generated carbon dioxide fluctuating due to the load fluctuation of the equipment that emits carbon dioxide. The purpose is to make the flow rates of hydrogen and carbon dioxide supplied to the metanation equipment stable and as constant as possible with respect to the flow rate of carbon and the flow rate of recovered carbon dioxide that fluctuates accordingly.

The effective utilization system of recovered carbon dioxide of the present invention uses a carbon dioxide separation and recovery facility that separates and recovers carbon dioxide from a gas containing carbon dioxide, a renewable energy power generation facility, and electric power obtained from the renewable energy power generation facility. It is equipped with a water electrolysis facility that electrolyzes water to generate hydrogen and a metanation facility that has a metanation reactor that produces methane using carbon dioxide and hydrogen, and stores the hydrogen produced by the water electrolysis facility. The hydrogen storage means and the carbon dioxide storage means for storing the carbon dioxide recovered by the carbon dioxide separation and recovery facility are further provided, and the hydrogen filling rate in the hydrogen storage means and the carbon dioxide filling rate in the carbon dioxide storage means are predetermined. It is configured to be adjusted so as to be within the range of, and to supply hydrogen and carbon dioxide to the metanation reactor when the filling rate of hydrogen and carbon dioxide is equal to or higher than a predetermined value.

According to the present invention, when the recovered carbon dioxide is effectively used, the generated power generated by the fluctuating renewable energy, the flow rate of the generated hydrogen fluctuating accordingly, and the generated carbon dioxide fluctuating due to the load fluctuation of the equipment that emits carbon dioxide. The flow rates of hydrogen and carbon dioxide supplied to the metanation equipment can be made stable and constant as much as possible with respect to the flow rate of carbon and the flow rate of recovered carbon dioxide that fluctuates accordingly.

It is a schematic block diagram which shows the recovered carbon dioxide effective utilization system of Example 1. FIG. It is a schematic block diagram which shows the recovered carbon dioxide effective utilization system of Example 1. FIG. It is a schematic diagram which shows the threshold value about the filling amount of the CO _{2 storage tank 9 of FIG.} It is a schematic diagram showing a threshold for the filling amount of the high pressure H ₂ storage tank 15 of FIG. It is a flow chart which shows the control method of the filling amount of the CO ₂ storage tank and the high pressure H _{2 storage tank of Example 1. FIG.} It is a figure which shows the example of the monitor screen display shown in FIG. It is a schematic block diagram which shows the recovered carbon dioxide effective utilization system of Example 2. It is a partially enlarged block diagram which shows one of the metanation reactors of Example 2. FIG. It is a flow chart which shows the control method of the filling amount of the CO ₂ storage tank and the high pressure H _{2 storage tank of Example 2. FIG.} It is a figure which shows the graph which is an example of the monitor screen display shown in FIG. It is a figure which shows the other graph to be displayed together with the graph shown in FIG. 9A. It is a block diagram which shows the recovered carbon dioxide effective utilization system of Example 3. It is a schematic diagram which shows the threshold value about the filling amount of the CO _{2 tank 515 of FIG.} It is a schematic diagram showing a threshold for the filling amount of H ₂ tanks 545 of FIG. 10. FIG. 5 is a flow chart showing a control method for starting and stopping _{the CO 2 recovery device 506 of FIG.} It is a flow chart which shows the control method which allows _{the CO 2} tank 515 of FIG. 10 to _{fill and release CO 2.} FIG. 5 is a flow chart showing a control method for starting and stopping the water electrolyzer 537 of FIG. It is a flow diagram illustrating a control method to allow charging and discharging of hydrogen in H ₂ tanks 545 of FIG. 10. It is a flow chart which shows the control method of CH _{4 manufacturing control apparatus 583 of FIG.} It is a schematic diagram which shows the additional threshold value about the charge amount of the CO _{2 tank 515 of FIG.} It is a schematic diagram showing an additional threshold for loading of H ₂ tanks 545 of FIG. 10. FIG. 5 is a flow chart showing another control method for permitting _{the CO 2} tank 515 of FIG. 10 to be _{filled and released with CO 2.} FIG. 5 is a flow chart showing another control method for permitting the filling and release of hydrogen in _{the H 2 tank 545 of FIG.} It is a block diagram which shows the recovered carbon dioxide effective utilization system of Example 5. It is a schematic diagram showing a threshold for the filling amount of H ₂ tanks 545 of FIG. 18. It is a schematic diagram showing a threshold for the filling amount of H ₂ tanks 546 of FIG. 18. FIG. 5 is a flow chart showing a control method for starting and stopping the water electrolyzer 537 of FIG. FIG. 5 is a flow chart showing a control method for permitting the filling and release of hydrogen in _{the H 2 tank 545 of FIG.} FIG. 5 is a flow chart showing a control method for permitting the filling and release of hydrogen in _{the H 2 tank 546 of FIG.} It is a flow chart which shows the control method of CH _{4 manufacturing control apparatus 583 of FIG.} It is a block diagram which shows the hydrogen production system using the hydrogen storage alloy of Example 6. FIG. 5 is a flow chart showing a control method for starting and stopping the water electrolyzer 537 of FIG. 23. It is a figure which shows the control method which permits the filling and release of hydrogen of the hydrogen storage alloy canister 572 of FIG. It is a figure which shows the control method which permits the filling and release of hydrogen of the hydrogen storage alloy canister 573 of FIG. It is a flow chart which shows the control method of CH _{4 manufacturing control apparatus.} It is a block diagram which shows the system of the methane production apparatus provided with the plurality of methaneization reactors of Example 7. It is a figure which shows the control method which detects the deterioration of the metanation catalyst of FIG. 27. It is a figure which shows an example of the control monitor screen of the charge amount of the CO _{2 storage means and the hydrogen storage means of Example 4.} It is a figure which shows an example of the control monitor screen of the charge amount of _{the CO 2} storage means and the hydrogen storage means of Example 5 or 6.

The present invention relates to a technique for effectively utilizing recovered carbon dioxide.

Hereinafter, examples will be described with reference to the drawings. The same components may be designated by the same reference numerals, and if the description is duplicated, the description may be omitted. Moreover, the present invention is not limited to the following examples.

FIG. 1 is a schematic configuration diagram showing a recovered carbon dioxide effective utilization system of this embodiment.

As shown in this figure, the plant 2 in various industrial fields has an exhaust gas emission facility 3. The generated exhaust gas is sent to the exhaust gas discharge facility 3 via the exhaust gas pipe 201 and discharged into the atmosphere. Here, the plant 2 includes a thermal power plant, a steel plant, a chemical plant, a microorganism utilization plant, and the like.

The recovered CO ₂ effective utilization system 1 (recovered carbon dioxide effective utilization system) includes a steam removing device 6, a CO ₂ liquefaction compressor 7, a CO ₂ storage tank 9 (carbon dioxide storage means), and a CO ₂ vaporizer 10. , Renewable energy power generation equipment 11, water electrolysis equipment 12, H ₂ compressor 13, high pressure H ₂ storage tank upstream on-off valve 14, high pressure H ₂ storage tank 15 (hydrogen storage means), CO ₂ heating and vessels 17a, comprises and _{H 2} heater 17b, methanation reactor 19a, 19b, and 19n, and the cooler 20, a gas-liquid separator 21. In this specification, the steam removing device 6 and the CO ₂ liquefaction compressor 7 are _{collectively referred to as "CO 2} separation and recovery equipment". A tank for storing the gas may be provided between the steam removing device 6 and the CO ₂ liquefaction compressor 7, and the gas from which the steam has been removed may be temporarily stored before being compressed.

Here, the CO ₂ separation and recovery equipment is an abbreviation for carbon dioxide separation and recovery equipment, and means equipment that separates and recovers carbon dioxide. Similarly, in the present specification, the names of systems, devices, equipment, etc. _{include chemical formulas such as "CO 2} ", "H ₂ ", and "CH ₄ ", which are "carbon dioxide" and "carbon dioxide", respectively. Represents "hydrogen", "methane", etc.

An on-off valve 8 on the upstream side of the _{CO 2 storage tank is provided between the CO 2} liquefaction compressor 7 and the CO ₂ storage tank 9. Between the CO ₂ storage tank 9 and CO ₂ vaporizer 10, CO ₂ flow rate adjusting valve 16a (carbon dioxide flow control valve) is provided. Between the high pressure _{H 2} storage tank 15 and _{H 2} heater 17b, _{H 2} flow rate adjusting valve 16b (hydrogen flow rate adjustment valve) is provided. Downstream of the CO ₂ heater 17a, CO ₂ flow meters 18a (carbon dioxide flow meter) is provided. Downstream of H ₂ heater 17b, _{H 2} flow meter 18b (hydrogen flow meter) is provided.

_{All or part of the exhaust gas (CO 2} mixed gas) flowing through the exhaust gas pipe 201 is supplied to the steam removing device 6 by the exhaust gas blower 5. The supply of exhaust gas can also be shut off by the exhaust gas shutoff valve 4.

In the water vapor removing device 6, water vapor is removed from the supplied exhaust gas. Steam removed gas is compressed by the CO ₂ liquefaction compressor 7, is liquefied CO ₂ contained in the gas is separated into a non-carbon dioxide gas 202 and carbon dioxide 203 (CO _2). After that, the carbon dioxide 203 is temporarily stored in the _{CO 2 storage tank 9.} Here, the CO ₂ storage tank 9 is _{an example of a CO 2} storage means, and the storage means is not limited to the tank.

In the above description, the gas supplied to the steam removing device 6 is described as "exhaust gas", but the gas supplied to the steam removing device 6 is not limited to the exhaust gas, and CO _{Any gas containing 2} can be a target. It is desirable that the concentration of _{CO 2} contained in the gas is high.

Further, in the water vapor removing device 6, it is desirable to remove sulfur oxides (SOx), nitrogen oxides (NOx) and other harmful components from the supplied gas. This is to prevent corrosion of pipes and equipment on the downstream side and deterioration of the catalyst.

In the renewable energy power generation facility 11, power is generated using renewable energy such as wind power and solar power. The electricity obtained thereby is divided into electricity 205 supplied to the electric power system and electricity 204 supplied to the water electrolysis facility 12. Here, all the electricity generated in the renewable energy power generation facility 11 may be supplied to the water electrolysis facility 12.

In the water electrolysis facility 12, electricity 204 is used to generate _{oxygen 206 (O 2} ) and hydrogen 207 (H _{2) from water.} Hydrogen 207 is _{compressed by the H 2} compressor 13 and stored in the high pressure H _{2 storage tank 15.} Here, the means for storing hydrogen 207 is not limited to the tank. On the other hand, oxygen 206 may be discharged to the outside of the system, but may be used to promote a chemical reaction in, for example, a thermal power plant, a steel plant, a chemical plant, or the like.

The metanational reactors 19a, 19b and 19n are arranged in parallel. In this specification, the metanation reactors 19a, 19b, 19n and their peripheral devices such as a flow rate control valve and a densitometer are collectively referred to as "metanation equipment".

The carbon dioxide in the CO _{2 storage tank 9 is vaporized in the CO 2} vaporizer 10, heated in the heater 17a, and sent to the metanation reactors 19a, 19b, 19n. On the other hand, the hydrogen of high pressure _{H 2} storage tank 15 is heated by the heater 17b, methanation reactor 19a, 19b, are sent to 19n. As shown in this figure, the hydrogen sent from the high-pressure H ₂ storage tank 15 merges with and mixes with the carbon dioxide sent from the _{CO 2} storage tank 9 upstream of the metanation reactors 19a, 19b, and 19n. Piping may be configured. It is desirable that these carbon dioxide and hydrogen are adjusted to an appropriate flow rate by the flow rate adjusting valves 16a and 16b and sent to the metanation reactors 19a, 19b and 19n. This adjustment is performed according to the dimensions of the metanation reactors 19a, 19b, 19n, the number of columns, and the like.

The reactions in the metanation reactors 19a, 19b, and 19n theoretically have a predetermined stoichiometric ratio as shown in the above reaction formula (1). Therefore, 4 mol of _{H 2} is supplied for 1 mol of _{CO 2.} However, since it is considered that the reaction is promoted by supplying more _{H 2} than the stoichiometric ratio, it is desirable to supply more than 4 mol of _{H 2} with respect to 1 mol of _{CO 2.}

Since the outlet gases of the metanational reactors 19a, 19b, and 19n _{contain H 2} O in addition to _{CH 4} , they are cooled by the cooler 20 and separated into methane 208 and water 209 by the gas-liquid separator 21. ..

As the catalyst used in the metanation reactors 19a, 19b, 19n, in addition to inorganic Ni / CeO (solid catalyst using an inorganic material), a biocatalyst that utilizes the functions of microorganisms such as bacteria should also be used. Can be done. In the present specification, these catalysts are collectively referred to as "methanation catalysts".

When an inorganic catalyst is used, it is desirable to provide heaters 17a and 17b. On the other hand, when a biocatalyst is used, a temperature control means other than the heaters 17a and 17b may be used in order to keep the temperature of the biocatalyst in an appropriate range.

In this figure, the metanational reactors 19a, 19b, and 19n are arranged in parallel, but they may be arranged in series in order to increase the reaction rate.

_{By adding the CO 2} storage tank 9 and the high-pressure H ₂ storage tank 15 to the configuration of the recovered CO ₂ effective utilization system 1, the amount _{of CO 2} recovered due to load fluctuations in the plant 2 such as a thermal power plant and the renewable energy power generation facility 11. And _{the fluctuation of the amount of H 2} generated can be mitigated before being supplied to the metanation equipment.

Hereinafter, the control of the recovered CO ₂ effective utilization system 1 will be described.

In order to supply a constant amount of reaction gas to the metanation equipment using the storage tank, it is necessary to set a threshold value and control it while measuring the filling amount of the storage tank. However, in the case of the control method using only the upper limit value and the lower limit value of the filling amount of the storage tank as the threshold value, _{the downtime of the water electrolysis equipment, the CO 2} separation and recovery equipment, and the metanation equipment becomes long. That is, the operating time of each facility is reduced.

Therefore, it is desirable to adopt a control method that further sets a threshold value to improve the operating rate.

Hereinafter, the level control method of each storage tank will be described with reference to FIGS. 2 to 5.

FIG. 2 shows a signal line for detection and control added to the recovered carbon dioxide effective utilization system of FIG.

In FIG. 2, the control device 101, the monitor 102, the CO ₂ filling amount measuring means 103a (carbon dioxide filling amount measuring means) and the H ₂ filling amount measuring means 103b (hydrogen filling amount measuring means) are added to the configuration of FIG. However, the signal line indicated by the broken line is added. The CO ₂ filling amount measuring means 103a is _{installed in the CO 2} storage tank 9, and the H ₂ filling amount measuring means 103b is _{installed in the high pressure H 2} storage tank 15.

The control device 101 _{acquires input signals from the CO 2} filling amount measuring means 103a, the H ₂ filling amount measuring means 103b, the CO ₂ flow meter 18a, and the H ₂ flow meter 18b, and obtains an input signal from the CO 2 filling amount measuring means 103a, the H 2 filling amount measuring means 103a, the exhaust gas shutoff valve 4, and the upstream side of the _{CO 2 storage tank.} off valve 8, the flow control valve 16a, 16b, and outputs a signal of operation to the water electrolyzer 12 and the high pressure _{H 2} storage tank upstream side switching valve 14.

In this embodiment, the items of the input signal and the output signal are set as described above, but if the effect of this embodiment is obtained, the items may be added or omitted, and the configuration is limited to the above. It's not something.

FIG. 3A shows the threshold value regarding the filling amount of _{the CO 2 storage tank 9.}

In the figure, measured by the CO ₂ loading measuring means 103a installed in CO ₂ storage tank 9, the filling amount of CO ₂ at a certain time and _{L C,} the CO ₂ that is set as the upper limit of _{L C} The first threshold value L _C1 , the second threshold value L _{C2 of CO 2} set as a value lower than the first threshold value L _C1 , and the lower limit value set as a lower value value than the second threshold value L _{C2 of CO 2} It shows the third threshold value _{LC3 of CO 2} that is present. That is, the second threshold value _LC2 is a value between the first threshold value _LC1 and the third threshold value _LC3. In addition, these threshold values may be expressed by the threshold value of the filling rate.

Figure 3B illustrates the threshold value for the filling quantity of the high-pressure H ₂ storage tank 15.

In this figure, the filling amount _{of H 2 at} a certain time measured by the H ₂ filling amount measuring means 103b _{installed in the high-pressure H 2 storage tank 15 is L H,} and the upper limit value of _{L H} is the first threshold _{value of H 2.} L _H1 , the second threshold value L _{H2 of H 2} set as a value lower than the first threshold value L _H1 , and the third threshold _{value of H 2} set as a lower limit value lower than _{the second threshold value L H2} . The threshold value L _H3 is shown. That is, the second threshold value L _H2 is a value between the first threshold value L _H1 and the third threshold value L _H3. In addition, these threshold values may be expressed by the threshold value of the filling rate.

Here, the filling rate is the filling amount of each tank at that time expressed as a percentage based on the maximum allowable filling amount of the tank.

In this embodiment, three threshold values are set, but if the effect of this embodiment is obtained, four or more threshold values may be set.

Hereinafter, a method for controlling the filling amount _{of the CO 2} storage tank and the high-pressure H _{2 storage tank in this embodiment will be described.} In all the operations described below, it is assumed that the control device 101 of FIG. 2 acquires an input signal and transmits an output signal.

FIG. 4 is a flow chart showing a control method of this embodiment.

In this figure, first, loading _{L C} of CO ₂ storage tank confirms whether more than a first threshold value _{L C1} (S901), the case often is supplying CO ₂ to CO ₂ storage tank 9 The exhaust gas shutoff valve 4 and the CO ₂ storage tank upstream on-off valve 8 are closed (S902). Then, to check whether the filling amount _{L C} is less than the second threshold _{L C2} (S903).

Loading _{L C} of CO ₂ in the storage tank 9 in step S901 is in the following cases: first threshold value _{L C1} is without operation of step S902, whether the filling amount _{L C} is less than the second threshold value _{L C2} Confirm (S903). Loading _{L C} is if less than the second threshold _{L C2} is opened exhaust gas shutoff valve 4 and CO ₂ storage tank upstream side switching valve 8 (S904). After that, it is confirmed whether the filling amount L _H in the high-pressure H ₂ storage tank is larger than the first threshold value L _{H1 (S905).}

Or loading _{L C} in step S903 is in the case of more than the second threshold value _{L C2} is without operation of step S904, loading _{L H} in the high pressure _{H 2} storage tank 15 is larger than the first threshold _{L H1} Is confirmed (S905). When the filling amount L _H is larger than the first threshold value L _H1 , the water electrolysis facility 12 is stopped to stop supplying _{H 2} to the high pressure H ₂ storage tank 15, _{and the high pressure H 2} storage tank is opened and closed on the upstream side. The valve 14 is closed (S906). After that, it is confirmed whether the filling amount L _H is smaller than the second threshold value L _{H2 (S907).} When the filling amount L _H in the high-pressure H ₂ storage tank 15 is smaller than the first threshold value L _H1 , it is confirmed whether _{the filling amount L H} is smaller than the second threshold value L _H2 without performing the operation of step S906. (S907). When the filling amount L _H is smaller than the second threshold value L _H2 , the water electrolysis facility 12 is operated and the high-pressure H ₂ storage tank upstream on-off valve 14 is opened (S908).

The steps up to this point are the steps of controlling whether or not each of the CO ₂ storage tank 9 and the high-pressure H _{2 storage tank 15 is filled with gas.}

Then, regardless of the Yes / No in the step S907, loading _{L C} is the second threshold value _{L C2} above, and filling amount _{L H} to check whether the second threshold _{L H2} or (S909). When this condition is satisfied, that is, when _{the filling amount of both CO 2} and H ₂ is equal to or higher than the second threshold value, the flow rate adjusting valves 16a and 16b are adjusted according to the number of towers and the condition of the metanation reactor. _{The supply of CO 2} and H ₂ at a predetermined flow rate designed in the above manner is started (S910). Further, regardless of Yes / No in step S909, it is confirmed whether _{the filling amount L C} is smaller than the third threshold value L _C3 or the filling amount L _H is smaller than the third threshold value L _{H3 (S911).} Then, when _{the filling amount of either CO 2} or H ₂ is lower than the third threshold value, both the flow rate adjusting valves 16a and 16b are closed (the opening degree is set to 0).

After that, regardless of Yes / No in step S911, it is confirmed whether or not the series of operations is completed (S913). When the operation is terminated, the termination process is performed (S914), and the operation is terminated. On the other hand, if the series of operations is not completed in step S913, the process returns to step S901 and is repeated until the above operation is completed.

FIG. 5 shows an example of the screen display of the monitor shown in FIG. In the graph in the figure, the horizontal axis represents the time and the vertical axis represents the gas filling rate in each tank. The solid line shows the hydrogen filling rate, and the alternate long and short dash line shows the carbon dioxide filling rate.

In FIG. 5, the input signal acquired from _{the CO 2} filling amount measuring means 103a _{installed in the CO 2} storage tank 9 and _{the H 2} filling amount measuring means 103b installed in the _{high pressure H 2} storage tank 15 as shown in FIG. 2 is used as the filling rate. The converted value and the set three threshold values are displayed in one graph. In other words, this graph shows the change over time in the filling rate of hydrogen and carbon dioxide, and displays the first threshold value, the second threshold value, and the third threshold value of hydrogen and carbon dioxide in one graph. In this example, the case where the respective threshold values of hydrogen and carbon dioxide are equalized is shown. The reference threshold value may be different for hydrogen and carbon dioxide.

As illustrated in FIG. 5, _{the filling rates of the CO 2} storage tank 9 and the high-pressure H ₂ storage tank 15 change as shown in a line graph by switching the flow rate adjusting valves 16a and 16b. In the following description of this figure, the symbols shown in parentheses correspond to the symbols with a horizontal axis (not the numerical values on the horizontal axis) and the positions of the dotted lines.

From the initial state until the _{filling rate of the tank with the lower filling rate of the CO 2} storage tank 9 and the high-pressure H ₂ storage tank 15 reaches the second threshold value (1), the CO ₂ storage tank 9 and the high-pressure H H ₂ Only storage in each tank is performed without sending the gas in the storage tank 15 to the metanation reactor.

After the filling rates of both tanks reach the second threshold, the gas supply to each tank is continued and the CO ₂ and H ₂ are supplied to the meta-nation reactor. When the filling rate exceeds the first threshold value, the supply of gas to the tank is stopped (2a, 2b). After this, the gas supply to the metanation reactor continues, so that the filling rate decreases.

Then, after the filling rates of both tanks fall below the second threshold value (3), the supply of gas to each tank is restarted. When the filling rate of the tank having the lower filling rate falls below the third threshold value (4), the supply of gas to the metanation reactor is stopped and only storage is performed.

Then, after the filling rates of both tanks reach the second threshold value (5), the gas supply to each tank is continued and the CO ₂ and H ₂ are supplied to the metanation reactor.

As described above, storage and supply to the metanation reactor are repeated.

That is, after the filling rate of the tank having the lower filling rate falls below the third threshold value, the metanation is suspended until the filling rates of both tanks reach the second threshold value, and the metanation is suspended during the other periods. I do. When both the filling rate of the CO ₂ storage tank 9 and the high-pressure H ₂ storage tank 15 is equal to or higher than the second threshold value, both storage and supply to the metanation reactor are performed.

In the present embodiment, the above control is described as being performed by the control device 101 of FIG. 2, but the present invention is not limited to this, and is similar to that of a central processing unit (CPU). It also includes the case where the flow control valve itself does not have a proper control device, that is, the filling rate is mechanically adjusted and the supply to the metanation reactor is turned on and off (start and stop) in part or in whole. Here, "mechanical" may be partially electric or electronic, or may be dispersedly arranged in each flow rate adjusting valve or the like. Further, the plurality of parts may be mechanically, electrically or electronically connected so that the operations, processes and the like of the respective parts are linked.

Further, the configuration represented by "equipment", "equipment", "means" and the like in the drawings and the above description can be interpreted as "process" in the method of using recovered carbon dioxide. For example, carbon capture and storage equipment is a carbon capture and storage process, renewable energy power generation equipment is a renewable energy power generation process, water electrolysis equipment is a water electrolysis process, metanation equipment is a metanation process, and hydrogen storage means. The hydrogen storage process and the carbon dioxide storage means can be interpreted as the carbon dioxide storage process.

According to this embodiment, it is possible to _{control the filling amount of the CO 2} storage tank and the high-pressure H ₂ storage tank, and avoid overfilling each storage tank with gas and emptying the gas in each storage tank. It becomes. Further, by performing level control as in this embodiment, it is possible to supply to the metanation reactor while filling each storage tank, and it is possible to improve the operating rate of each facility.

In this embodiment, a method of detecting and controlling when any one of the plurality of metanational reactors becomes inoperable will be described with reference to FIGS. 6 to 9B.

FIG. 6 is a schematic configuration diagram showing a recovered carbon dioxide effective utilization system of this embodiment.

As shown in this figure, the reaction gas shutoff valves 104a, 104b, 104n are installed in the pipes, etc. (upstream side) near the inlets of the metanation reactors 19a, 19b, 19n, respectively, and the reaction gas shutoff valves 104a, 104b, 104n are installed in the pipes, etc. (downstream side) near the outlets. The CO ₂ concentration meters 105a, 105b, and 105n (carbon dioxide concentration measuring means) are added.

In this embodiment as well, as in the first embodiment, only one metanation reactor is installed in the series direction, but the reaction is not sufficiently completed and is connected in the series direction (in the case of connecting in the series direction). In this case, hereinafter referred to as "when a plurality of reactors are installed in series"), the reaction gas shutoff valves 104a, 104b, 104n are located on the upstream side of the reactor located most upstream among the reactors in series. Install and install CO ₂ densitometers 105a, 105b, 105n at the outlets of all reactors.

_{With the addition of these components, the CO 2} concentration signals from all the CO 2 concentration meters 105a, 105b, and 105n are added to the input signals of the control device 101, and all the signals of _{the CO 2} concentration are added as the output destinations of the control device 101. Reaction gas shutoff valves 104a, 104b, 104n are added, and an operation signal is output.

In this embodiment, the input / output signal items are set as described above, but if the effects of this embodiment can be achieved, the items may be added or omitted, and the items are not limited.

FIG. 7 is an enlarged view of one (i-th) of the metanation reactors in the N tower.

In this figure, a reaction gas shutoff valve 104i is installed on the upstream side of the methanation reactor 19i, and a CO ₂ concentration meter 105i is installed on the downstream side.

Tower number of methanation reactors N tower, the gas flow rate supplied to one methanation reactor _F M, among _{F M,} CO ₂ gas flow rate _F MCO2, _{H 2} gas flow rate and _{F MH2.} The F _MH2 / F _MCO2 is preferably 4.0 or more.

Therefore, if the N column are all running normally, the gas supply amount of the total is F _M × N. CO ₂ is _{F MCO2} × N, _{H 2} becomes _{F MH2} × N.

Further, the i-th methanation reactor of CO ₂ concentration C _i of the outlet gas of _19i, the concentration indicating that the reactor becomes not run by the catalyst deterioration or other factors C _i, and _c. When a plurality of reactors are installed in series, a threshold value of a concentration indicating that _{the reactor cannot be operated may be set in the CO 2 concentration of each reactor outlet gas in the series direction. That, C i, c} may be a threshold concentration of _{C i.}

For all the operations described below, the control device 101 acquires an input signal and outputs an operation signal as an output signal.

FIG. 9A shows an example of the screen display of the monitor similar to that of FIG.

_{In this embodiment, the outlet CO 2} concentrations of the above-mentioned plurality of metanational reactors may be displayed together as a graph on the screen shown in FIG. 9A.

FIG. 9B is a _{screen display of the outlet CO 2} concentration of each metanation reactor as a graph.

On the monitor screen shown in this figure, the outlet CO _{2 concentration acquired from the CO 2 concentration meter 105i of each reactor and the concentrations Ci and c} (threshold concentration) indicating that the operation has become inoperable are displayed as a graph. ing. When a plurality of reactors are installed in series, a plurality of Ci _{and c} may be displayed on the monitor.

_{The state in which the outlet CO 2} concentration of the reactor 2 (corresponding to the second metanation reactor) shown by the broken line starts to rise sharply means that, for example, the catalyst installed inside the reactor 2 is deactivated. Is shown. When the catalyst is a biocatalyst, it indicates that the living body has died, for example. In this case, when the outlet CO ₂ concentration reaches Ci _{, c} , the reaction gas shutoff valve is closed and the gas supply is stopped.

The screen display shown in this figure may be freely switchable from the screen display shown in FIG. 9A. In other words, the graphs of FIGS. 9A and 9B may be displayed on the screen independently.

FIG. 8 shows a control method of this embodiment.

In this figure, steps S910 and S912 are changed from the control flow shown in the first embodiment (FIG. 4).

In step S910, an operation of opening the reaction gas shutoff valves 104a, 104b, 104n of all the reactors is added in order to supply the metanational reactors 19a, 19b, 19n. In step S912, in order to stop the reaction in the metanational reactors 19a, 19b and 19n, an operation of closing the reaction gas shutoff valves 104a, 104b and 104n of all the reactors is added.

Further, in this embodiment, in the case of Yes in step S909, a new step is added after the next step S910.

As in step S910, _{the flow control valves 16a and 16b downstream of the CO 2} storage tank 9 and the high pressure H ₂ storage tank 15 are adjusted to start supplying to all the metanation reactors 19a, 19b and 19n, and at the same time, all of them. The reaction gas shutoff valves 104a, 104b, 104n installed at the inlets of the methanation reactors 19a, 19b, 19n are opened. The total methanation reactor outlet gas which has reacted with the reactor, all methanation reactor 19a, 19b, CO ₂ concentration meter 105a installed at the exit of 19n, 105b, 105n by CO ₂ concentration _{C i} There is measured (S915), the signal of the CO ₂ concentration _{C i} is sent to the controller 101, it is monitored on the monitor 102 (FIG. 9B). When all the metanational reactors 19a, 19b and 19n are reacting normally, the CO ₂ concentration of the outlet gas is lower than the _{concentration Ci and c indicating inoperability.}

However, in any of the reactors, due to a problem of the catalyst (or biocatalyst) and utilities such as in the reactor, when the reaction is no longer successful, the exit gas CO ₂ concentration C _i of the reactor is raised Eventually, it exceeds _{Ci, c.} In that case, _{the metanational reactor exceeding Ci and c} closes the reaction gas shutoff valve 104i at the inlet of the reactor in order to terminate the reaction (S916). Then, the number of reactors that have become inoperable is counted (S917), and the number of towers X is calculated by subtracting the number of reactors that have become inoperable from the number N towers of all reactors (S918). Then, the flow rate _{F M} × X of X tower min (CO ₂ flow rate _{F MCO2} × X, _{H 2} flow rate _{F MH2} × X) such that the flow regulating valve 16a, and outputs a signal of operation to 16b (S919 ).

In the case of Yes in step S909, after these operations are completed, or in the case of No in step S909, the process proceeds to step S911 without performing these operations. Then, it is confirmed whether the filling amount L _C is smaller than the third threshold value L _C3 or the filling amount L _H is smaller than the third threshold value L _{H3 (S911).} When the filling amount L _C is smaller than the third threshold value L _C3 , or when the filling amount L _H is smaller than the third threshold value L _H3 , the opening degrees of the flow rate adjusting valves 16a and 16b are set in order to stop the metanation reaction. Is set to 0, and all reaction gas shutoff valves 104a, 104b, and 104n are closed (S912).

Further, in step S911, regardless of Yes / No, it is confirmed whether or not the series of operations shown in this embodiment is completed (S913), and if it is completed, the end process is performed (S914) to end the operation.

If the series of operations is not completed in step S913, the process returns to step S901 and is repeated until the above operation is completed.

According to this embodiment, at the same time as performing the control as in the first embodiment, the metanation reactor that has become inoperable and the number of towers thereof are monitored, and the flow rate of _{CO 2} and H _{2 is controlled.} Since a predetermined flow rate is supplied to the metanation reactor of No. 1, it is possible to proceed the reaction without any trouble.

FIG. 10 is a configuration diagram showing a recovered carbon dioxide effective utilization system of this embodiment.

First, _{the recovery of CO 2} will be described.

The plant 501 is a thermal power generation plant, a steel plant, a cement plant, a chemical plant, etc., and the exhaust gas 502 is a trace substance such as soot, nitrogen oxide (NOx), and sulfur oxide (SOx) due to equipment (not shown). Is released into the atmosphere from the chimney 503.

CO ₂ recovery is started by introducing the exhaust gas 502 after removing soot, nitrogen oxides (NOx) and sulfur oxides (SOx) into the CO ₂ recovery device 506. By opening the shutoff valves 504 and 510, _{starting the CO 2} recovery device 506, and starting the blower 505, the exhaust gas 502 is introduced into the _{CO 2 recovery device 506.} After recovering CO ₂ , the exhaust gas is returned to the upstream of the chimney 503 and released into the atmosphere from the chimney 503.

The method of recovering CO ₂ is the chemical absorption method using an aqueous amine solution, adsorption using a solid adsorbent for adsorbing CO _2, and CO ₂ has a membrane separation method using a selectively permeable membrane which transmits, using either good.

The chemical absorption method is a method in which an aqueous amine solution _{absorbs CO 2} in an absorption tower, the aqueous amine solution that has absorbed CO ₂ is transported to a regeneration tower, and the regeneration tower releases _{CO 2.} The CO ₂ absorption reaction is an exothermic reaction and requires cooling of the amine aqueous solution. Further, the CO ₂ release reaction is an endothermic reaction and requires heating of an aqueous amine solution.

The adsorption method is a method in which _{exhaust gas containing CO 2} is aerated through a solid adsorbent _{to adsorb CO 2} , and then the aeration of the exhaust gas is stopped and CO ₂ is desorbed by heating. The CO ₂ adsorption reaction is an exothermic reaction, and it is necessary to cool the adsorbent in order to adsorb _{more CO 2.} On the other hand, _{in order to desorb more CO 2} adsorbed, it is necessary to heat the adsorbent.

Like these two methods, CO ₂ recovery requires both heating and cooling energies, and developments are underway to reduce that energy. In recent years, a membrane separation method that _{allows CO 2} to permeate is expected as a method for reducing energy.

_CO 2 recovered by the CO ₂ recovery apparatus 506 (507) is liquefied in the compressor 508, it is stored in CO ₂ tank 515. If there is a non-condensable gas 509 that does not liquefy in the compressor 508, discard it. Water vapor is also liquefied by the compressor 508. Although not shown, the water liquefied in the upper stage of the compressor 508 is discarded because it is liquefied before _{CO 2.} A valve 511 is provided between the compressor 508 and the CO _{2 tank 515.} The CO ₂ tank 515 is provided with a liquid level gauge 517.

The recovered carbon dioxide effective utilization system includes a CO ₂ production control device 581. The CO ₂ production control device 581 can receive data on the operating status of the plant 501 and the like. Further, the CO ₂ production control device 581 can receive data from the shutoff valve 504, the blower 505, the CO ₂ recovery device 506, the compressor 508, the valve 511 and the valve 513, and transmits data for control and the like. Is also possible.

Next, _{the production of H 2} will be described.

The electric power obtained by the renewable energy power generation device 531 represented by wind power generation and solar power generation is utilized as the system output electric power 532.

However, due to the rapid introduction of renewable energy, oversupply of electric power is predicted depending on the day and time, and the acceptance of renewable energy may be stopped. In that case, the renewable energy power generation device 531 must be forcibly stopped and the supply and demand of electric power must be adjusted.

If the renewable energy power generation device 531 is operated while it is forcibly stopped, the generated power becomes surplus power, and it is necessary to utilize the power.

Further, the electric power obtained by the renewable energy power generation device 531 fluctuates greatly and cannot be used as it is. Therefore, a storage battery is introduced, and the charge / discharge control is used to mitigate power fluctuations and make the power usable. However, the power fluctuation of the renewable energy power generation device 531 is a mixture of single-cycle fluctuations that fluctuate in seconds or less, and long-period fluctuations of days or more, and the power fluctuations are mitigated only by the storage battery. If this happens, a large-capacity storage battery will be required, and the introduction cost will increase.

On the other hand, even if a large-capacity storage battery is provided, the time during which the charge rate (SOC) increases is short, and the capacity of the storage battery cannot be effectively used. Therefore, it is desired to reduce the size of the storage battery and the introduction cost.

As a means for solving the above-mentioned problems of utilizing surplus electric power and reducing the cost of introducing a storage battery, it is promising to manufacture _{H 2 using the electric power obtained by the renewable energy power generation device 531.}

When there is surplus electric power of the renewable energy power generation device 531 or a sudden increase in electric power exceeding the charging speed of the storage battery, electric power is supplied to the water electrolyzer 537 to produce hydrogen 534. The high pressure compressor 536 and stored in _{H 2} tank 545. Between the compressor 536 and _{H 2} tank 545, valve 541 is provided. The H ₂ tank 545, a pressure gauge and thermometer 547 is provided.

The water electrolyzer 537 includes an alkaline electrolytic cell using an alkaline aqueous solution and a PEM electrolytic cell using a solid polymer membrane. The former has large products and is rated operation. The latter can be operated in accordance with power fluctuations and can mitigate fluctuations in renewable energy power. Here, PEM is an abbreviation for Polymer Electrolyte Membrane (solid polymer membrane).

The oxygen 533 generated in the water electrolyzer 537 is released into the atmosphere. Oxygen 533 may be used to promote combustion in plants 501 and the like.

The recovered carbon dioxide effective utilization system includes an H ₂ production control device 582. The H ₂ production control device 582 can receive data on electric power and the like generated by the renewable energy power generation device 531 and data on the pressure gauge and the thermometer 547 provided in _{the H 2 tank 545.} Further, the H ₂ manufacturing control device 582 can receive data from the valve 535, the compressor 536, the valve 541 and the valve 543, and can also transmit data for control and the like.

Next, _{the production of CH 4} will be described.

CH ₄ is _{produced by supplying CO 2} and H ₂ by the reaction of the above reaction formula (1). In the recovered carbon dioxide effective utilization system, a methanation reactor 561 (methanation reactor) manufactured by _{CH 4 is provided.} The methanation reactor 561 contains a solid catalyst using an inorganic material or a biocatalyst using a bacterium.

Whether it is a solid catalyst or a biocatalyst, there is an optimum temperature, and it is necessary to maintain that temperature. It is necessary to heat to the temperature at which the reaction occurs. Further, the reaction of the reaction formula (1) is an exothermic reaction, and once the reaction starts, it is necessary to cool the reaction so as to maintain the optimum temperature.

That is, the fluctuation of the reaction of the reaction formula (1) hinders the maintenance of the optimum temperature. Therefore, it is desirable that the reaction rate be stable, and further, it is desirable that the reaction rate be constant.

In order to keep the reaction rate constant, it is necessary to keep the supply flow rates of _{CO 2} and H _{2 constant.} Therefore, _{the pipe for CO 2} is provided with a flow rate adjusting valve 522 and a flow meter 524, and _{the pipe for H 2} is provided with a flow rate adjusting valve 551 and a flow meter 553.

CO ₂ is supplied from the CO ₂ tank 515. The piping for CO ₂ is provided with a valve 513 and a flow rate adjusting valve 522. CO ₂ in CO ₂ tank 515 is a high pressure liquid, expands by the flow regulating valve 522 is opened, turns into gas. At that time, the temperature drops. If it is supplied to the methanation reactor 561 at that temperature, it may not reach the optimum temperature, and in preparation for such a case, a heater 523 for _{CO 2 is provided. A flow meter 524 for CO 2} is provided on the downstream side of the heater 523 to measure the flow rate. The flow rate adjusting valve 522 is controlled so that the flow rate becomes constant.

H ₂ is supplied from the H ₂ tank 545. A piping for H ₂ is provided with a valve 543 and a flow control valve 551. Of _{H 2} H ₂ tank 545 is a high pressure, _{H 2} is expanded by the flow regulating valve 551 opened. At that time, the temperature drops. If it is supplied to the methanation reactor 561 at that temperature, it may not reach the optimum temperature, and in preparation for such a case, a heater 552 for _{H 2 is provided.} Downstream of the heater 552 provided with a flow meter 553 for _{H 2,} to measure the flow rate. The flow rate adjusting valve 551 is controlled so that the flow rate becomes constant.

As described above, methane 562 is produced at a constant flow rate.

If the filling rate of the CO ₂ in CO ₂ tank 515 becomes 1 (full), it is necessary to stop the filling of CO _2. On the other hand, when the filling rate becomes 0 (empty), it cannot be supplied to the methaneization reactor 561, so it is necessary to stop the methane production.

Further, when the filling rate of H _{2 in the H 2} tank 545 becomes 1 (full), it is necessary to stop the filling of _{H 2.} On the other hand, when the filling rate becomes 0 (empty), it cannot be supplied to the methaneization reactor 561, so it is necessary to stop the methane production.

The recovered carbon dioxide effective utilization system includes a CH ₄ production control device 583. The CH ₄ manufacturing control device 583 can receive the data of the flow meter 524 and the flow meter 553. Further, the CH ₄ manufacturing control device 583 can transmit a control signal to the flow rate adjusting valve 522 and the flow rate adjusting valve 551. Further, the CH ₄ manufacturing control device 583 can transmit and receive data to _{and from the CO 2} manufacturing control device 581 and the H _{2 manufacturing control device 582.} Further, a monitor 584 (display device) is connected to _{the CH 4 manufacturing control device 583.} The monitor 584 can confirm the control status, the detected value of each sensor, and the like. Therefore, the monitor 584 can also confirm the data _{of the CO 2} production control device 581 and the H _{2 production control device 582.} The monitor 584 may be a mobile terminal such as a smartphone.

FIG. 11A is a schematic view showing each threshold value regarding the filling amount of _{the CO 2 tank 515 of FIG.}

In FIG. 11A, the filling amount of CO ₂ tank 515 shows the CO ₂ tank storage limit level _{L C1} is the threshold limit. For example, a value smaller than 1 may be set, such as 0.9. Similarly, it shows the lower limit of _{CO 2 tank storage level LC3} , which is the lower threshold. For example, a value larger than 0 may be set, such as 0.1.

CO ₂ filling factor is calculated from the amount of stored measured values of the tank L _{C (hereinafter} referred to as "measured value of CO ₂ tank filling rate".) If becomes L _C1 above, the control for stopping the filling of the CO ₂ do. On the other hand, when the measured value _{L C} of CO ₂ tank filling rate becomes _{L C3} Hereinafter, a control to stop supplying the CO ₂ in the methanation reactor 561.

FIG. 11B is a schematic view showing each threshold value regarding the filling amount of _{the H 2 tank 545 of FIG.}

In FIG. 11B, _{the H 2} tank storage upper limit level L _H1 , which is the upper limit threshold value, is shown for _{the filling amount of the H 2 tank 545.} For example, a value smaller than 1 may be set, such as 0.9. _{Similarly, the H 2} tank storage lower limit level L _H3 , which is the lower threshold, is shown. For example, a value larger than 0 such as 0.1 may be set.

H ₂ filling factor is calculated from the amount of stored measured values of the tank L _{H (hereinafter} referred to as "measurement value of H ₂ tank filling rate".) If becomes L _H1 above, the control for stopping the filling of the H ₂ do. On the other hand, when the measured value L _{H of the H 2} tank filling rate becomes L _{H 3 or less, the supply of H 2} to the methaneization reactor 561 is controlled to be stopped.

FIG. 12A is a flow chart showing a process of starting and stopping _{the CO 2} recovery device 506 of FIG. 10, which is controlled by _{the CO 2 production control device 581 of FIG. 10.}

As shown in FIG. 12A, first, the value of the flag Plant of the operating status of the plant 501 is received from the control device of the plant 501 (S101).

Then, it is determined whether or not the plant 501 is in operation (S102). If the flag Plant = 1 indicating that the plant 501 is in operation, the value of the flag Cflag _{CO2 for CO 2 storage is received from the CO 2} tank 515 (S103). _{If Cflag CO2} = 1 indicating that CO ₂ storage is permitted (S104), the valve 504 is opened (S105), the CO ₂ recovery device 506 is activated (S106), the blower 505 is activated (S107), and compression is performed. The machine 508 is started (S108), the valve 511 is opened (S109), and the CO ₂ tank 515 is controlled to store _{CO 2.} After that, the process returns to S101 (S110).

On the other hand, _{if Cflag CO2} = 0, which does not allow storage (S104), the compressor 508 is stopped (S121), the valve 511 is closed (S122), the blower 505 is stopped (S123), and the CO ₂ recovery device 506 is turned on. It is stopped (S124), the shutoff valve 504 is closed (S125), and control is performed so that CO _{2 is not stored in the CO 2 tank 515.} After that, the process returns to S101 (S110).

Further, even if the flag Plant = 0 in which the plant 501 is stopped, the CO ₂ tank 515 is similarly controlled not to store _{CO 2.}

This control is performed at regular time intervals.

FIG. 12B is a flow chart showing a control method for permitting _{the CO 2} tank 515 of FIG. 10 to be _{filled and released with CO 2.}

As shown in FIG. 12B, the value of the flag _{Cflag CO2} to allow CO ₂ storage in CO ₂ tank 515, and the value of the flag _{DFLAG CO2} to allow CO ₂ emission from CO ₂ tank 515, mounted on the CO ₂ tank respectively receiving the values of the filling ratio _{L C} obtained from the measured value of the liquid level gauge 517 are (S151). Then, in accordance with the threshold for loading of CO ₂ tank 515 resets the _{DFLAG CO2} of _{Cflag CO2.}

Then, comparing the filling ratio of the measured value _{L C} and CO ₂ tank storage upper limit level _{L C1} (S152). L _C is large, that is, in the case of _{L C> L C1,} sets the _{Cflag CO2} = 0 for stopping the CO ₂ filled in the CO ₂ tank 515 (S153). If L _C> not _{L C1} sets the _{Cflag CO2} = 1, to allow the filling of CO ₂ in the CO ₂ tank 515 (S154). In either case, the process returns to S151 (S155).

On the other hand, it compares the measured value _{L C} and CO ₂ tank storage lower limit level _{L C3} fill factor (S161). L _C is small, that is, in the case of _L C _{<L C3,} sets a _{DFLAG CO2} = 0 for stopping the CO ₂ emission from CO ₂ tank 515 (S162). If L _C <not _{L C3,} set _{DFLAG CO2} = 1, to allow CO ₂ emission from CO ₂ tank 515 (S163). In either case, the process returns to S151 (S164).

This control is performed at regular time intervals.

Next, the control method of the water electrolyzer 537 of FIG. 10 will be described.

FIG. 13A is a flow chart showing a control method for starting and stopping the water electrolyzer 537.

As shown in the figure, it receives the value of the flag Cflag _H2 for permitting of _{H 2} storage in _{H 2} tanks 545 of _{H 2} production control device 582 (S201). Then, it is determined whether or not storage is permitted using _{Cflag H2 (S202).} If Cflag _H2 = 1, the water electrolyzer 537 is started (S203), the electric power of the renewable energy power generation device 531 is received (S204), the valve 535 is opened (S205), and the compressor 536 is started (S206). , Valve 541 is opened (S207), and control is performed to store _{H 2 in the H 2} tank 545.

On the other hand, in S202, _{if Cflag H2} = 0, which does not allow storage, the compressor 536 is stopped (S211), the power of the renewable energy power generation device 531 is cut off (S212), the valve 535 is closed (S213), and the valve 535 is closed (S213). the water electrolysis device 537 stops (S214), the valve 541 is closed (S215), the control without storage of _{H 2} into _{H 2} tank 545.

In either case, the process returns to S201 (S208).

This control is performed at regular time intervals.

FIG. 13B is a flow chart showing a control method for permitting the filling and release of hydrogen into _{the H 2 tank 545 of FIG.}

As shown in the figure, the value of the flag Cflag _H2 for permitting of _{H 2} storage in _{H 2} tank 545, and the value of the flag DFLAG _H2 for permitting of _{H 2} emission from _{H 2} tank 545, mounted in _{H 2} tank 545 _{The value of the filling rate L H} obtained from the measured values of the pressure gauge and the thermometer 547 is received (S251). Then, in accordance with the threshold for loading of _{H 2} tank 545 resets the DFLAG _H2 of Cflag _H2.

Next, the filling rate L _H and the H ₂ tank storage upper limit level L _H1 are compared (S252). L _H is large, i.e. in the case of _{L H> L H1,} it sets the Cflag _H2 = 0 to stop the filling of _{H 2} to _{H 2} tank 545 (S253).

On the other hand, when L _H > L _H1 , Cflag _H2 = 1 is set _{, H 2} filling is permitted in the _{H 2} tank 545, _{and the filling rate L H} is compared with the H ₂ tank storage lower limit level L _H3 (S261). ). When L _H <L _H3 , _{Dflag H2} = 0 for stopping _{CO 2} emission from the _{H 2} tank 545 is set (S262). On the other _hand, if not L H _{<L H3,} set the DFLAG _H2 = 1, permits of _{H 2} emission from _{H 2} tank 545.

In either case, the process returns to S251 (S254).

This control is performed at regular time intervals.

FIG. 14 is a flow chart showing a control method of _{the CH 4 manufacturing control device 583 of FIG.}

As shown in FIG. 14, the value of the flag Dflag _{CO2 that allows CO 2} emission and the value of the flag Dflag _{H2 that allows H 2} storage are received (S301). Then, when _{the conditions of Dflag CO2} = 1 and Dflag _H2 = 1 (S302, S303) are satisfied, both the valve 513 for _{CO 2 and the valve 543 for H 2} are opened (S304) to manufacture _{CH 4.} .. Under other conditions, both the valve 513 and the valve 543 are closed (S311), and the production of _{CH 4 is discontinued.} Here, the flow rate of CO _2, as in the measured value of CO ₂ for the flow meter 524 becomes a predetermined flow rate, the control of adjusting a flow rate control valve 522. The flow rate of H _2, as in measurements of _{H 2} for flow meter 553 reaches a predetermined flow rate, the control of adjusting a flow rate control valve 551 (S305).

In either case, the process returns to S301 (S306).

This control is performed at regular time intervals.

In the control method of Example 3, the filling rate of the CO ₂ tank 515 is greater than _{L C3,} and, if the filling rate of the _{H 2} into _{H 2} tank 545 is greater than _{L H3,} the methanation reactor 561 CO ₂ and H ₂ can be supplied.

However, if the filling rate of the CO ₂ tank 515 is less than _{L C3,} to stop the supply of the CO ₂ to the methanation reactor 561, CO ₂ tank as the filling factor of the CO ₂ tank 515 is greater than _{L C3} 515 is filled with _{CO 2.} If it _{becomes larger than LC3, CO 2} is supplied to the methanation reactor 561 again. At this time, the less the supply flow rate to the CO ₂ methanation reactor 561 than the filling flow to the tank 515, the filling rate to CO ₂ tank 515 rises, CH ₄ is produced at a constant flow rate.

On the other hand, the more the supply flow rate to the methanation reactor 561 than the filling flow to the CO ₂ tank 515, the filling rate of the CO ₂ tank 515 _decreases, smaller than _{L C3.} That is, the filling rate of _{the CO 2} tank 515 vibrates with the LC ₃ in between, and the production flow rate of _{CH 4 also vibrates.} This vibration reduces the production flow rate of _{CH 4.} Here, the "manufacturing flow rate" refers to the flow rate of the gas that is manufactured and flows out of the reactor.

If the filling rate of the CO ₂ tank 515 becomes larger than _{L C1,} CO ₂ filling of CO ₂ into the tank 515 is stopped, the filling rate of the CO ₂ tank 515 to methanation reactor 561 to be less than _{L C1} Supply CO _2. If it _becomes smaller than LC1, the CO ₂ tank 515 is filled with _{CO 2 again.} At this time, the more the supply flow rate to the CO ₂ methanation reactor 561 than the filling flow to the tank 515, the filling rate to CO ₂ tank 515 decreases, CH ₄ is produced at a constant flow rate. On the other hand, the more filling flow rate of the supply flow rate to the methanation reactor 561 to the CO ₂ tank 515, the filling rate of the CO ₂ tank 515 _rises to a value higher than the _{L C1.} That is, the filling rate of the CO ₂ tank 515 vibrates across the _{L C1.} This vibration reduces the recovery flow rate of _{CO 2} emitted from the plant 501.

Similarly, in H ₂ tank 545, the filling rate of the _{H 2} tank 545 becomes smaller than _{L H3,} stop of _{H 2} feed to the methanation reactor 561, the filling rate of the _{H 2} tank 545 is greater than _{L H3} The H ₂ tank 545 _{is filled with H 2} as described above. If it _{becomes larger than L H3, H 2} is supplied to the methanation reactor 561 again. At this time, the less the supply flow rate to the methanation reactor 561 than the filling flow to _{H 2} tank 545, the filling rate to _{H 2} tank 545 rises, CH ₄ is produced at a constant flow rate. On the other hand, if the supply flow rate to the methanation reactor 561 is larger than the filling flow rate to the _{H 2 tank 545, the filling rate of the H 2} tank 545 is lower than _{that of L H3.} That is, the filling rate of _{the H 2} tank 545 vibrates across _{L H 3,} and the production flow rate of _{CH 4 also vibrates.} This vibration reduces the production flow rate of _{CH 4.}

If the filling rate of the H ₂ tank 545 becomes larger than _{L H1, H 2} filling of _{H 2} to the tank 545 is stopped, the filling rate of the _{H 2} tank 545 to methanation reactor 561 to be less than _{L H1} supplying the H _2. If it _becomes smaller than LC1, the H ₂ tank 545 is filled with _{H 2 again.} At this time, the more the supply flow rate to the methanation reactor 561 than the filling flow to _{H 2} tank 545, the filling rate to _{H 2} tank 545 decreases, CH ₄ is produced at a constant flow rate. On the other hand, the more filling flow rate of the supply flow rate to the methanation reactor 561 to the _{H 2} tank 545, the filling rate of the _{H 2} tank 545 _rises to a value higher than the _{L C1.} That is, the filling rate of the _{H 2} tank 545 _{oscillates L C1.} This vibration suppresses the electric power received from the renewable energy power generation, and the surplus electric power of the renewable energy is not utilized.

In this embodiment, in order to suppress the vibration of the production flow rate of _{CH 4} , a threshold condition is added to each filling rate _{of the CO 2} tank 515 and the H _{2 tank 545 in the control.}

FIG. 15A is a schematic diagram showing an additional threshold value for the filling amount of _{the CO 2 tank 515 of FIG.}

FIG. 15B is a schematic diagram showing an additional threshold value for the filling amount of _{the H 2 tank 545 of FIG.}

In Figure 15A, an intermediate level of _{L C2} is provided between the threshold _{L C1} and _{L C3} of CO ₂ tank 515.

In FIG. 15B, an intermediate level L _H2 is provided between the thresholds L _H1 and L _{H3 of the H 2 tank 545.}

In the following, in _{the control flow of the CO 2} production control device 581 of _{FIG. 10, the control flow of starting and stopping the CO 2} recovery device 506 is the same as that of FIG. 12A, and thus the description thereof will be omitted.

FIG. 16 is a flow chart showing another control method for permitting _{the CO 2} tank 515 of FIG. 10 to be _{filled and released with CO 2.}

As shown in FIG. 16, the value of the flag _{Cflag CO2} to allow CO ₂ storage in CO ₂ tank 515, and the value of the flag _{DFLAG CO2} to allow CO ₂ released from the CO ₂ tank 515, is attached to the CO ₂ tanks the value of the filling ratio _{L C} obtained from the measured value of the liquid level meter 17 respectively receive (S401). Then, in accordance with the threshold for loading of CO ₂ tank 515 resets the _{DFLAG CO2} of _{Cflag CO2.}

Then, comparing the filling ratio _{L C,} and a CO ₂ tank storage upper limit level _{L C1} (S402). For _{L C>} L _C1, sets the _{Cflag CO2} = 0 for stopping the filling of the CO ₂ to the CO ₂ tank 515 (S403).

On the other _hand, if it is not L _{C> L C1,} adding the condition L C _{<L C2,} it determines (S404). When this condition is satisfied, the CO ₂ tank 515 is allowed to be filled with _{CO 2 by setting Cflag CO2 = 1 (S405).} In _S404, if the condition is not satisfied in the L C _{<L C2,} without changing the flag, the process proceeds to S406.

And remains Cflag _CO2 = _0, by incorporating this control if not a condition _L C _{<L C2,} it is possible to suppress the vibration across the _{L C1.}

Also, comparing the filling ratio _{L C,} and a CO ₂ tank storage lower limit level _{L C3} (S411). In _the case of L C _{<L C3,} sets a _{DFLAG CO2} = 0 for stopping the release of CO ₂ from the CO ₂ tank 515 (S412). L _C <if not _{L C3, L C>} added condition of _{L C2,} determines (S413). When this condition is satisfied, Dflag _CO2 = 1 and CO ₂ emission is permitted (S414). If the condition is not satisfied in the L _{C> L C2,} without changing the flag, the process proceeds to S415.

By incorporating this control, it is possible to suppress the vibration that sandwiches the _LC3.

Control of interest _is, L _C> In _{L C1} rather, and _is that _{the Cflag CO2} is not re-set a condition not _L C _{<L C2. Further,} L C _{<the L C3} rather, _and, L _C> is _{that DFLAG CO2} is not re-set a condition not _{L C2.} This means that to provide a _{Cflag CO2} = 1 and _{DFLAG CO2} = 1 time, and a CO ₂ emission from CO ₂ supply and CO ₂ tank to CO ₂ tank simultaneously.

_{Here, L C2,} there may be two _{L C2-1} and _{L C2-2.} L _{C2-1 is} a filling rate level for holding the state of the _{Cflag CO2} = 0 after the timing when the _{L C>} L _C1. L _{C2-2 is} a filling rate level for holding the state of _{DFLAG CO2} = 0 after the timing when the _L C _{<L C3.} Such control is performed at regular time intervals.

In the control flow of the water electrolyzer 537 of FIG. 10, the control flow for starting and stopping the water electrolyzer 537 is the same as that of FIG. 13A, and thus the description thereof will be omitted.

FIG. 17 is a flow chart showing another control method for allowing _{the H 2} tank 545 of FIG. 10 to be filled and released with hydrogen.

As shown in FIG. 17, the value of the flag Cflag _H2 for permitting of _{H 2} storage in _{H 2} tank 545, and the value of the flag DFLAG _H2 for permitting of _{H 2} emission from _{H 2} tank 545, mounted in _{H 2} tank _{The values of the filling rate L H} obtained from the measured values of the pressure gauge and the thermometer 547 are received (S501). Then, in accordance with the threshold for loading of _{H 2} tank 545, to reset the Cflag _H2 and DFLAG _H2.

The filling factor L _H is compared with the H ₂ tank storage upper limit level L _H1 (S502). When L _H > L _H1 , _{Cflag H2} = 0 for stopping the filling of H _{2 into the H 2} tank 545 is set (S503). If L _H > L _H1 in _{S502, the condition L H} <L _H2 is added (S504). If this condition is satisfied, the Cflag _H2 = 1, to allow the filling of _{H 2} to _{H 2} tank 545. If the condition of L _H <L _H2 is not satisfied in S504, the process proceeds to S506 without changing the flag.

By incorporating this control, it is possible to suppress the vibration that sandwiches _{the L H1.}

Further, the filling rate L _H is compared with the H ₂ tank storage lower limit level L _H3 (S511). When L _H <L _H3 , _{Dflag H2} = 0 for stopping the release of H _{2 from the H 2} tank 545 is set (S512). If L _H <L _H3 , _{the condition of L H} > L _H2 is added (S513). If this condition is satisfied, the _{DFLAG CO2} = 1, permits of _{H 2} emission from _{H 2} tank 545 (S514). If the condition of L _H > L _H2 is not satisfied, the process proceeds to S515 without changing the flag.

By incorporating this control, it is possible to suppress the vibration that sandwiches _{the L H3.}

The control of interest is that Cflag _H2 is not reset under the _{condition that L H} > L _H1 and L _H <L _H2. Further, _{Dflag H2} is not reset under the _{condition that L H} <L _H3 and L _H > L _H2 are not satisfied. This provided a time Cflag _H2 = 1 and DFLAG _H2 = 1, which means that for a and _{H 2} released from the _{H 2} feed and _{H 2} tanks to _{H 2} tanks simultaneously.

_{Here, L H2,} there may be two _{L H2-1} and _{L H2-2.} L _H2-1 is a filling factor level that maintains the state of _{Cflag CO2} = 0 from the time when L _H > L _H1. L _H2-2 is a filling factor level that maintains the state of _{Dflag H2} = 0 from the time when L _H <L _H3.

Such control is performed at regular time intervals.

_{Since the control flow of the CH 4} manufacturing control device 583 of FIG. 10 is the same as that of FIG. 14, the description thereof will be omitted.

In Example 4, one CO ₂ tank is filled and released with _{CO 2 , and one H 2} tank is _{filled and released with H 2} at the same time, and CH ₄ is efficiently produced by a methanation reactor. To do.

In the CO ₂ tank, _{the safety of CO 2} itself is high, and there are cases where filling and discharging proceed at the same time.

On the other hand, H ₂ may explode when heated as an extremely flammable or highly flammable gas and under high pressure. Therefore, it is also necessary to prevent backflow to other devices and improve the safety of the equipment by not allowing filling and discharging to proceed simultaneously in the same tank.

Accordingly, in this embodiment, a plurality of H ₂ tank, selectively using a tank for emitting a tank to be filled, so that is switched used.

FIG. 18 is a configuration diagram showing a recovered carbon dioxide effective utilization system of this embodiment.

The difference from FIG. 10 in this figure is _{the addition of the H 2} tank 546, which is equipped with valves 542 and 544 upstream and downstream thereof, and a pressure gauge and a thermometer 548 for measuring the pressure of _{the H 2 tank 546.} .. In H ₂ tanks 545 and 546, when filled with H ₂ to one and shall not fill the other, also when discharging of H ₂ from one shall perform operations that do not release of H ₂ from the other.

FIG. 19A is a schematic view showing a threshold value regarding the filling amount of _{the H 2 tank 545 of FIG.}

FIG. 19B is a schematic view showing a threshold value regarding the filling amount of _{the H 2 tank 546 of FIG.}

As shown in FIG. 19A, the H ₂ tank storage upper limit level L _{H1_A} is provided _{for the H 2 tank 545.} For example, a value smaller than 1 may be set, such as 0.9. Further, the H ₂ tank storage lower limit level L _{H3_A} is provided. For example, a value larger than 0 may be set, such as 0.1. Here, L _{H_A} is a filling rate calculated from the measured value of the hydrogen storage amount of the H _{2 tank 545.}

Similarly, in FIG. 19B, the H ₂ tank storage upper limit level L _{H1_B} is provided _{for the H 2 tank 546.} For example, a value smaller than 1 may be set, such as 0.9. Further, the H ₂ tank storage lower limit level L _{H3_B} is provided. For example, a value larger than 0 may be set, such as 0.1. Here, L _{H_B} is a filling rate calculated from the measured value of the hydrogen storage amount of the H _{2 tank 546.}

_{As the threshold value regarding the filling amount of the CO 2} tank 515 of FIG. 18, three threshold values shown in FIG. 15A are provided. _{In the control flow of the CO 2} production control device 581 of FIG. 18, _{the control flow of starting and stopping the CO 2} recovery device 506 is the same as that of FIG. 12A. _{The control flow for permitting the CO 2} tank 515 of FIG. 18 to be _{filled and released with CO 2} is the same as that of FIG. Therefore, the description of these control flows will be omitted.

FIG. 20 is a flow chart showing a control method for starting and stopping the water electrolyzer 537 of FIG.

As shown in FIG. 20, receives the value of the flag _{Cflag H2_A} permitting of _{H 2} storage in _{H 2} tank 545, and the value of the flag _{Cflag H2_B} permitting of _{H 2} storage in _{H 2} tank 546 (S601). If Cflag _{H2_A} = 1 or Cflag _{H2_B} = 1 permitting storage (S602, S609), the water electrolyzer 537 is activated (S603). Then, the electric power of the renewable energy power generation device 31 is received (S604), the valve 535 is opened (S605), and the compressor 536 is started (S606).

Then, _{if Cflag H2_A} = 1, the valve 541 is opened and _{H 2} is stored _{in the H 2} tank 545. If Cflag _{H2_B} = 1, the valve 542 is opened and _{H 2 is stored in the H 2} tank 546 (S607).

On the other hand, _{Cflag H2_A} = 0 do not allow storage _{of H 2} tank 545 and, if _{Cflag H2_B} = 0 do not allow of _{H 2} storage in _{H 2} tank 546 (S602, S609), stops the compressor 536 (S611) , remove power renewable energy power generating apparatus 531 (S612), the valve 535 is closed (S613), a water electrolysis device 537 stops (S614), the valve 541 and the valve 542 is closed (S615), _{H 2} Control not to store _{H 2} in tank 545 and H ₂ tank 546.

In either case, the process returns to S601 (S608).

This control is performed at regular time intervals.

FIG. 21A is a flow chart showing a control method for permitting the filling and release of hydrogen in _{the H 2 tank 545 of FIG.}

As shown in FIG. 21A, the value of the flag _{Cflag H2_A} permitting of _{H 2} storage in _{H 2} tank 545, and the value of the flag _{DFLAG H2_A} permitting of _{H 2} emission from _{H 2} tank 545, mounted in _{H 2} tank _{The values of the filling rate L H_A} obtained from the measured values of the pressure gauge and the thermometer 547 are received (S701). Accordance threshold for loading of H ₂ tank _545, resetting the _{Cflag H2_A} and _{Dflag H2_A.}

Comparing the filling factor _{L H_A} and _{H 2} tankage upper limit level _{L H1_A} (S702). For _{L H_A>} L _{H1_A,} setting the _{Cflag H2_A} = 0 for stopping the filling of _{H 2} to _{H 2} tank 545, and a _{Dflag H2_A} = 1 to allow of _{H 2} emission from _{H 2} tank 545 (S703). If not _{L H_A>} L _{H1_A,} comparing the filling factor _{L H_A} and _{H 2} tank storage lower limit level _{L H3} (S711). For _{L H_A} <L _{H3_A,} set the _{Dflag H2_A} = 0 for stopping of _{H 2} emission from _{H 2} tank 545, and a _{Cflag H2_A} = 1 for filling with _{H 2} into _{H 2} tank 545 (S712 ).

In either case, the process returns to S701 (S704).

This control is performed at regular time intervals.

FIG. 21B is a flow chart showing a control method for permitting the filling and release of hydrogen in _{the H 2 tank 546 of FIG.}

As shown in FIG. 21B, the value of the flag _{Cflag H2_B} to allow storage of _{H 2} into _{H 2} tank 546, and the value of the flag _{DFLAG H2_B} to allow release of _{H 2} from the _{H 2} tank 545, in _{H 2} tank The attached pressure gauge and the value of the filling factor L _{H_B} obtained from the measured values of the thermometer 548 are received (S751). Accordance threshold for loading of H ₂ tank _546, resetting the _{Cflag H2_B} and _{Dflag H2_B.}

Comparing the filling factor _{L H_B} and _{H 2} tankage upper limit level _{L H1_B} (S752). For _{L H_B>} L _{H1_B,} the _{Cflag H2_B} = 0 for stopping the filling of _{H 2} to _{H 2} tank 546, and a _{Dflag H2_B} = 1 for permitting release of _{H 2} from the _{H 2} tank 546 Set (S753). If not _{L H_B>} L _{H1_B,} comparing the filling factor _{L H_B} and _{H 2} tank storage lower limit level _{L H3_B} (S761). For _{L H_B} <L _{H3_B,} set the _{Dflag H2_B} = 0 for stopping of _{H 2} emission from _{H 2} tank 546, and a _{Cflag H2_B} = 1 for filling with _{H 2} into _{H 2} tank 546 (S762 ).

In either case, the process returns to S751 (S754).

Such control is performed at regular time intervals.

FIG. 22 is a flow chart showing a control method of _{the CH 4 manufacturing control device 583 of FIG.}

As shown in FIG. 22, receives the value of the flag _{DFLAG H2_A} and _{DFLAG H2_B} allow two _{H 2} storage, and the value of the flag _{DFLAG CO2} to allow CO ₂ emission (S801). Then, according to these values, the valves 543 and 544 for _{H 2} and the valves 513 for _{CO 2 are operated.}

When Dflag _{H2_A} = 1 (S802), when Dflag _{H2_B} = 0 and Dflag _CO2 = 1 (S803), the valve 543 is opened, the valve 544 is closed, and the valve 513 is opened (S804). ).

When Dflag _{H2_A} = 0 (S802), when Dflag _{H2_B} = 1 and Dflag _CO2 = 1 (S803), the operation of closing the valve 543, opening the valve 544, and opening the valve 513 is performed (S804). ), CH ₄ is manufactured.

If Dflag _{H2_A} = 0 and Dflag _{H2_B} = 0, or Dflag _CO2 = 0, the operation of closing all of the valves 543, 544 and 513 (S812) is performed to prevent _{CH 4 from being manufactured.}

Here, and the flow rate of _{H 2,} the measurement value of the _{H 2} for flowmeter 553 so that the flow rate command from CH ₄ production controller 583, a control for adjusting a flow rate control valve 551. The flow rate of CO ₂ is the measured value of CO ₂ for the flow meter 524 so that the flow rate of the flow rate command from CH ₄ production controller 583, a control for adjusting a flow rate control valve 522 (S805).

In either case, the process returns to S801 (S806).

This control is performed at regular time intervals.

This embodiment having a plurality of H ₂ tanks can also be applied as a control method when the number of renewable energy power generation devices 531 is increased, the hydrogen production flow rate is increased, and the number of H _{2 tanks is increased from one to two.} .. That is, _{it means that the control method of the second embodiment in which one H 2} tank is used may be changed to the control method of the present embodiment.

Also, increasing the recovery rate of the CO ₂ tanks, even if you increase the CO ₂ tanks, may be applied a method of controlling the H ₂ tank of the present embodiment.

As a means for storing hydrogen, there is a hydrogen storage alloy. The hydrogen storage alloy is used by being built in a metal pressure vessel (hereinafter referred to as "canister"). When hydrogen is occluded in a hydrogen storage alloy, it generates heat, so the canister is occluded while cooling. On the other hand, when hydrogen is released, it absorbs heat, so the canister is released while being heated. Therefore, hydrogen storage alloys cannot simultaneously charge and release hydrogen.

Therefore, it is desirable to apply the control method of Example 5. It is necessary to measure the hydrogen filling rate in the hydrogen storage alloy. There is also a direct measurement method, but for hydrogen storage alloys, the hydrogen filling rate is estimated using the amount of hydrogen calculated from the hydrogen flow rate before and after the canister, using the adsorption equilibrium relationship that indicates pressure dependence and temperature dependence. can do.

FIG. 23 is a configuration diagram showing a hydrogen production system using the hydrogen storage alloy of Example 6.

In FIG. 23, the difference from the hydrogen production system portion of FIG. 18 is that a medium pressure tank 571 and a hydrogen flow meter 574 downstream thereof are provided, and a hydrogen storage alloy canister instead of the _{H 2 tank.} It is provided with 572 and 573.

The medium pressure tank 571 is for alleviating fluctuations in the hydrogen production flow rate so that the hydrogen storage alloy is filled with a constant pressure. The capacity does not have to be large as it is not intended for storage. It also includes a pressure gauge and a thermometer 575 that measure the pressure and temperature of the medium pressure tank. The hydrogen filling rate in the hydrogen storage alloy is estimated together with the measured value in the hydrogen flow meter 574.

During the control flow of the CO ₂ production control device, the control flow _{for starting and stopping the CO 2} recovery device is the same as in FIG. 12A, and the control flow for permitting the _{CO 2} tank to be _{filled and released with CO 2 is shown in FIG.} Since they are the same, the description thereof will be omitted.

FIG. 24 is a flow chart showing a control method for starting and stopping the water electrolyzer 537.

As shown in the figure, it receives the value of the flag _{Cflag H2_A} permitting of _{H 2} stored in the hydrogen storage alloy canister 572, and the value of the flag _{Cflag H2_B} permitting of _{H 2} stored in the hydrogen storage alloy canister 573 (S951) .. If Cflag _{H2_A} = 1 or Cflag _{H2_B} = 1 allowing storage (S952, S971), the water electrolyzer 537 is started (S953), the power of the renewable energy power generation device 531 is received (S954), and the valve 535 is opened. (S955), and the compressor 536 is started (S956).

_{The pressure PH2_tank} of the medium pressure tank 571 is read (S957), and the pressure _{is increased until the storage pressure PH2_HSA of the hydrogen storage alloy is reached} , that is, until the condition of PH2_tank> _{PH2_HSA} is satisfied (S958).

_Thereafter, if _{Cflag H2_A} = 1, then start cooling of the hydrogen storage alloy canister 572 (S959), and the valve 541 opens, the valve 543 is closed (S960), control for occluding of _{H 2} into hydrogen storage alloy canister 572 do.

On the other hand, _{if Cflag H2_B} = 1, cooling of the hydrogen storage alloy canister 573 is started (S959), the valve 542 is opened, the valve 542 is opened, the valve 544 is closed (S960), and the hydrogen storage alloy canister 573 is set. of H ₂ to the control occluding.

Further, _{Cflag H2_A} = 0 do not allow of _{H 2} stored in the hydrogen storage alloy canister 572 and,, _{Cflag H2_B} = 0 if (S952, S971) does not permit of _{H 2} stored in the hydrogen storage alloy canister 573, stop the compressor 536 (S972), the power of the renewable energy power generation device 531 is cut off (S973), the valve 535 is closed (S974), and the water electrolyzer 537 is stopped (S975).

_{After that, the cooling of the hydrogen storage alloy canister 57 2} was stopped, the cooling of the hydrogen storage alloy canister 573 was stopped (S976), the valves 541 and 542 were closed (S977), and H 2 was added to the hydrogen storage alloy canisters 57 2 and 573. Control not to store.

In either case, the process returns to S951 (S961).

This control is performed at regular time intervals.

Here, the _{threshold values for the filling amount of the CO 2} tank may be the three threshold values shown in FIG. 15A, and the threshold values for _{the H 2} filling rate of each of the hydrogen storage alloy canisters 572 and 573 are shown in FIGS. 19A and 19A for the _{H 2 tank.} 19B is fine.

FIG. 25A is a flow chart showing a control method for permitting the filling and release of hydrogen in the hydrogen storage alloy canister 572 of FIG. 23.

As shown in FIG. 25A, the value of the flag _{Cflag H2_A} permitting of _{H 2} storage in the hydrogen storage alloy canister 572, and the value of the flag _{DFLAG H2_A} permitting of _{H 2} release from the hydrogen storage alloy canister 572, medium-pressure tank _{The values of the filling rate L H_A} calculated from the measured values of the pressure gauge and the thermometer 575 attached to the 571 are received (S1001). Reset Cflag _{H2_A} and Dflag _{H2_A} .

The filling factor L _{H_A} is compared with the storage upper limit level L _{H1_A} (S1002). When L _{H_A} > L _{H1_A , Cflag H2_A} = 0 for stopping the filling of H _{2 into the hydrogen storage alloy canister 572 and Dflag H2_A} = 1 for permitting _{H 2} emission from the hydrogen storage alloy canister 572 are set. (S1003). If L _{H_A} > L _{H1_A} is not satisfied in S1002, the filling factor L _H is compared with the storage lower limit level L _{H3_A} (S1011). When L _{H_A} <L _{H3_A , Dflag H2_A} = 0 for stopping the release of H ₂ from the hydrogen storage alloy canister 572 and Cflag _{H2_A} = 1 for _{allowing H 2} filling to the hydrogen storage alloy canister 572 are set ( S1012).

In either case, the process returns to S1001 (S1004).

FIG. 25B shows a control method for permitting the filling and release of hydrogen in the hydrogen storage alloy canister 573 of FIG.

As shown in FIG. 25B, the value of the flag _{Cflag H2_B} permitting of _{H 2} storage in the hydrogen storage alloy canister 573, and the value of the flag _{DFLAG H2_B} permitting of _{H 2} release from the hydrogen storage alloy canister 573, medium-pressure tank _{The value of the filling rate L H_B} calculated from each measured value of the pressure gauge attached to the 571 and the thermometer 575 is received (S1101), and Cflag _{H2_B} and Dflag _{H2_B} are reset.

The filling factor L _{H_B} is compared with the storage upper limit level L _{H1_B} (S1102). When L _{H_B} > L _{H1_B , Cflag H2_B} = 0 for stopping the filling of H _{2 into the hydrogen storage alloy canister 573 and Dflag H2_B} = 1 for permitting _{H 2} emission from the hydrogen storage alloy canister 573 are set. do. If L _{H_B} > L _{H1_B} is not satisfied in S1102, the filling factor L _{H_B} is compared with the storage lower limit level L _{H3_B} (S1111). When L _{H_B} <L _{H3_B , Dflag H2_B} = 0 for stopping the release of H _{2 from the hydrogen storage alloy canister 573 and Cflag H2_B} = 1 for filling the hydrogen storage alloy canister 573 with H ₂ are set ( S1112).

In either case, the process returns to S1101 (S1104).

This control is performed at regular time intervals.

FIG. 26 is a flow chart showing a control method _{of the CH 4 manufacturing control device.}

As shown in the figure, receives the value of the flag _{DFLAG H2_A} and _{DFLAG H2_B} allow two _{H 2} storage, and the value of the flag _{DFLAG CO2} to allow CO ₂ release (S1201), the valve for the _{H 2} 543 , Valve 544 and valve 513 for _{CO 2 are operated.}

When Dflag _{H2_A} = 1 (S1202), when Dflag _{H2_B} = 0 and Dflag _CO2 = 1 (S1203), the hydrogen storage alloy canister 572 is heated. When Dflag _{H2_A} = 0 (S1202), Dflag _{H2_B} = 1 (S1211), and Dflag _CO2 = 1 (S1203), the hydrogen storage alloy canister 573 is heated (S1204). _Thereafter, the valve 543 is opened by _{Dflag H2_A} = _1, the operation of the valve 544 and opens at _{Dflag H2_B} = 1 (S1205), based on the flow rate command from CH ₄ production controller 583 _{(S1206), Dflag H2_A} = The flow rate adjusting valve 522 is adjusted by 1 and the flow rate adjusting valve 551 is adjusted by _{Dflag H2_B = 1 to control the flow rate (S1207).}

In cases other than the above, heating of the hydrogen storage alloy canisters 572 and 573 is stopped (S1212). Then, the valves 543 and 544 are closed (S1213).

In either case, the process returns to S1201 (S1108).

This control is performed at regular time intervals.

As the _{amount of CO 2} recovered increases, it _{is necessary to add more CO 2} storage means, and with the addition of renewable energy power generation equipment, it becomes necessary to add more hydrogen storage means. In addition, it will be necessary to add more methanation reactors.

A methanation catalyst such as a solid catalyst or a biocatalyst is built in the methanation reactor. This example applies to any of Examples 3 to 6 and targets a plurality of methanation reactors having a built-in metanation catalyst.

The methanation catalyst is affected by trace components in the gas and gradually deteriorates. This, CO _in reactions ₂ and _{H 2} from CH ₄ are produced, which means that CO ₂ and _{H 2} unreacted increases progressively during production gas. The deterioration rate of the methanation catalyst is different for each of the plurality of methanation reactors.

Therefore, it is necessary to detect a methanation reactor that is judged to be inoperable and replace the metanation catalyst.

FIG. 27 is a configuration diagram showing a system of a methane production apparatus including a plurality of methaneization reactors of Example 7.

Here, n methanation reactors 601-1, 601-2, 601-n are connected in parallel, and each of them is filled with a methanation catalyst. Valves 602-1, 602-2, 602-n were provided at the inlets of the respective methanation reactors 601-1, 601-2, 601-n, and CO ₂ concentration meters 603-1, 603-2, respectively, were provided at the outlets. 603-n and valves 604-1, 604-2, 604-n are provided. The gas produced by the methanation catalyst, as shown in the reaction formula (1), since the CH ₄ and _{H 2} O are mixed, of _{H 2} O is condensed into water 607 by a cooler 605 and gas-liquid separator 606 To produce methane 608.

Deterioration of the methanation catalyst results in higher _{unreacted CO 2} and H _{2 concentrations in methane 608.} Therefore, for example, a CO ₂ concentration meter was provided at the outlet of each methanation reactor. The densitometer may be a concentration of _{H 2} meter or CH ₄ densitometer. However, when the CH ₄ concentration is used as an index, a lower concentration indicates deterioration of the metanation catalyst. The densitometer is not particularly limited in terms of the measurement principle as long as it is a means for measuring the concentration (concentration measuring means).

FIG. 28 is a flow chart showing a control method for detecting deterioration of the metanation catalyst of FIG. 27.

As shown in FIG. 28, receives the i-th methanation reactor 601-i CO ₂ concentration _{C CO2-i} measured in CO ₂ concentration meter 603-i at the outlet of (S1301). When the conditions of C _CO2-i > C _{CO2-I, ref} are satisfied (S1302), the inlet valve 602-i is closed and the outlet valve 604-i is closed (S1304). Here, C _{CO2-I, ref} is the maximum concentration that the metanation catalyst considers to be normal, and is a predetermined CO ₂ concentration.

If the supply of the mixed gas _{of CO 2} and H ₂ to the methanation reactor 601-i is to be stopped, it is necessary to reduce the flow rates of _{CO 2} and H _{2 supplied to the entire methanation reactor (S1303).} ). If the methanation reactor are the same size, each flow rate of the supplied CO ₂ and H ₂ each methanation reactor are the same, each of the n methanation reactor supplying CO ₂ and H ₂ The flow rate is reduced by 1 / n. The condition of C _CO2-i > C _{CO2-I, ref} is transmitted to the methane production control device and reflected in the command of each flow rate of _{CO 2} and H _2. In other words, when the deterioration of the metanation catalyst is detected, the amount supplied to the methanation reactor containing the deteriorated metanation catalyst is subtracted and supplied to the metanation facility.

After the operation of closing the inlet valve 602-i and closing the outlet valve 604-i, the metanational catalyst is replaced. After the work is completed, the work end is manually input (S1305). When the control device determines that the work is completed (S1306), the inlet valve 602-i is opened and the outlet valve 604-i is opened (S1307), and the CO ₂ and H ₂ supplied to the n methanation reactors are charged. The flow rate is restored to each flow rate (S1308), and the operation of the methanation reactor 601-i is controlled to be restarted.

This control is performed at regular time intervals (S1309), but the progress of the operation is temporarily stopped during the metanation catalyst replacement work.
In Example 4, _{there are three threshold values for the filling amount of the CO 2} storage means and the hydrogen storage means, and in Example 5 or 6, since there are a plurality of hydrogen storage means, the CO ₂ storage means and the hydrogen storage means By displaying each filling amount and threshold value on the control monitor, the driver can easily grasp the operation status of the effective utilization system of recovered carbon dioxide.

FIG. 29 is a diagram showing an example of a control monitor screen of the filling amount of _{the CO 2 storage means and the hydrogen storage means of Example 4.}

As shown in this figure, _{it is desirable to display on the screen whether the CO 2} storage means and the hydrogen storage means are currently in the filled state or the released state. That is, to display the DFLAG _H2 to allow release to _{Cflag CO2, DFLAG CO2} and hydrogen storage means to permit release to _Cflag H2, CO ₂ storage means to allow the filling to the hydrogen storage means to allow the filling to the CO ₂ storage means I am doing it.

In addition, _{the filling rate of each of the CO 2} storage means and the hydrogen storage means, and the corresponding change in the filling amount with time are displayed as a graph. It is desirable that three thresholds are displayed in each graph.

FIG. 30 is a diagram showing an example of a control monitor screen of the filling amount of _{the CO 2 storage means and the hydrogen storage means of Example 5 or 6.}

There is one CO ₂ storage means, and it is controlled by using three threshold values, two hydrogen storage means are used, and each of them is switched and used by using two threshold values.

As shown in this figure, _{it is desirable to display on the screen whether the CO 2} storage means and the hydrogen storage means are currently in the filled state or the released state. That, _Cflag H2_A to allow _Cflag CO2 to allow filling the CO ₂ storage means, _{DFLAG CO2} to allow release to CO ₂ storage means, filling the two hydrogen storage _{means, Cflag H2_B,} and two hydrogen storage means release Dflag _H2 and Dflag _{H2_B} are displayed.

In addition, _{the filling rate of each of the CO 2} storage means and the hydrogen storage means, and the corresponding change in the filling amount with time are displayed as a graph. It is desirable that the graph of the CO ₂ storage means shows three threshold values, and the graph of the hydrogen storage means shows two threshold values and two filling rates or filling amounts.

The above tank is a container for storing carbon dioxide, hydrogen, etc. in a gaseous state. The above canister is a container containing a hydrogen storage alloy.

Hereinafter, the descriptions of Examples 3 to 7 will be collectively described.

In the effective utilization system of recovered carbon dioxide, the first threshold of carbon dioxide and the second of carbon dioxide are in descending order of the value of the carbon dioxide filling rate calculated from the carbon dioxide filling amount measured by the carbon dioxide filling amount measuring means. A threshold and a third threshold of carbon dioxide are set, and when the filling rate of carbon dioxide is equal to or higher than the first threshold of carbon dioxide, the filling of carbon dioxide in the carbon dioxide storage tank is stopped and the filling rate of carbon dioxide becomes high. The filling is held stopped until it drops to the second threshold of carbon dioxide, and when the filling rate of carbon dioxide falls below the second threshold of carbon dioxide, the filling of carbon dioxide is restarted, and the filling rate of carbon dioxide is further reduced. When is below the third threshold of carbon dioxide, the emission of carbon dioxide from the carbon dioxide storage tank is stopped, and the emission is kept stopped until the filling rate of carbon dioxide increases to the second threshold of carbon dioxide. It is desirable to restart the emission of carbon dioxide when the filling rate of carbon dioxide falls below the second threshold of carbon dioxide.

Regarding the hydrogen filling rate calculated from the hydrogen filling amount measured by the hydrogen filling amount measuring means, the first threshold for hydrogen, the second threshold for hydrogen, and the third threshold for hydrogen are set in descending order of the value, and the filling rate of hydrogen is set. When is equal to or higher than the first threshold of hydrogen, the filling of hydrogen into the hydrogen storage means is stopped, the stop of filling is held until the filling rate of hydrogen drops to the second threshold of hydrogen, and the filling rate of hydrogen is maintained. When it falls below the second threshold of hydrogen, the filling of hydrogen is restarted, and when the filling rate of hydrogen falls below the third threshold of hydrogen, the release of hydrogen from the hydrogen storage means is stopped, and the hydrogen is charged. It is desirable to keep the release stopped until the filling rate increases to the second threshold of hydrogen, and restart the release of hydrogen when the filling rate of hydrogen falls below the second threshold of hydrogen.

The hydrogen storage means includes a plurality of hydrogen storage tanks or a plurality of canisters containing a hydrogen storage alloy, and the hydrogen storage means has a switching valve, and one of the plurality of hydrogen storage tanks or canisters can be used as hydrogen. It is desirable to operate the switching valve so that it is used for storage and one of the other is used for the release of hydrogen.

The hydrogen storage means includes a plurality of hydrogen storage tanks or a plurality of canisters containing a hydrogen storage alloy, and the hydrogen storage means has a switching valve, and one of the plurality of hydrogen storage tanks or canisters can be used as hydrogen. It is desirable to operate the switching valve so that it is used for storage and one of the other is used for the release of hydrogen.

It is desirable that the metanation reactor contains a solid catalyst using an inorganic material that produces methane from carbon dioxide and hydrogen, or a metanation catalyst containing a biocatalyst using bacteria.

It is desirable that the flow rate of carbon dioxide and the flow rate of hydrogen supplied to the methanation reactor can be adjusted respectively.

The methanation facility includes a plurality of metanational reactors, and a means for measuring the concentration of carbon dioxide, hydrogen, or methane is provided on the downstream side of each metanational reactor, and the measured value of the concentration is used. , It is desirable to detect the deterioration of the metanation catalyst.

When the deterioration of the metanation catalyst is detected, the supply of carbon dioxide and hydrogen to the metanation reactor in which the deterioration is detected is stopped, and the flow rate of carbon dioxide and hydrogen flowing into the metanation reactor is increased, respectively. It is desirable to supply the deducted flow rate to the metanation equipment.

As a display device used in the effective utilization system of recovered carbon dioxide, the change with time of the filling rate or the filling amount of each of the carbon dioxide storage means and the hydrogen storage means is displayed in a graph, and further, the carbon dioxide storage means and the hydrogen storage are displayed in the graph. It is desirable to display the threshold of the means.

In addition, it is desirable to display the filling and releasing states of the carbon dioxide storage means and the hydrogen storage means on the same screen.

1: Recovery CO ₂ effective utilization system 2: Plant 3: Exhaust emission equipment 4: Exhaust emission shutoff valve 5: Exhaust blower, 6: Steam removal device, 7: CO ₂ liquefaction compressor, 8: CO ₂ storage tank upstream side switching valve, 9: CO ₂ storage tank, 10: CO ₂ vaporizer 11: renewable energy facilities, 12: water electrolyzer, 13: _{H 2} compressor, 14: high pressure _{H 2} storage tank upstream side switching Valve, 15: High pressure H ₂ storage tank, 16a: CO ₂ flow control valve, 16b: H ₂ flow control valve, 17a: CO ₂ heater, 17b: H ₂ heater, 18a: CO ₂ flow meter, 18b: H ₂ flow meter, 19: metanation reactor, 20: cooler, 21: gas-liquid separator, 101: control device, 102: monitor, 103a: CO ₂ filling amount measuring means, 103b: H ₂ filling amount measuring means, 104a, 104b, 104n: reaction gas shutoff valve, 105a, 105b, 105n: CO ₂ concentration meter, 201: exhaust gas piping, 202: gas other than carbon dioxide, 203: carbon dioxide, 204, 205: electricity, 206: oxygen, 207: hydrogen, 208: methane, 209: water, 501: plant, 502: exhaust gas, 503: chimney, 504: shutoff valve, 505: blower, 506: CO ₂ recovery device, 507: CO ₂ , 508: compressor, 509: Non-condensable gas, 511, 512, 513, 514: Valve, 515: CO ₂ tank, 517, 518: Liquid level gauge, 521: Vaporizer, 522: Flow control valve, 523: Heater, 524: Flow rate Total, 531: Renewable energy generator, 532: System output power, 533: Oxygen, 534: Hydrogen, 535: Valve, 536: Compressor, 537: Water electrolyzer, 538: Rectifier, 541, 542, 543, 544 : Valve, 545, 546: H ₂ tank, 547, 548: Pressure gauge and thermometer, 551: Flow control valve, 552: Heater, 535: Flow meter, 561: Methanization reactor, 562: Methane, 571: Medium pressure tank, 572, 573: Hydrogen storage alloy canister: 574: Flow meter, 575: Pressure gauge and thermometer, 581: CO ₂ production control device, 582: H ₂ production control device, 583: CH ₄ production control device, 584: Monitor, 601-1, 601-2, 601-n: Methanization reactor, 602-1, 602-2, 602-n: Valve, 603-1, 603-2, 603-n: CO2 densitometer , 604-1, 604-2, 604-n: valve, 605: cooler, 606: gas-liquid separator, 607 : Water, 608: Methane.

Claims (23)

A carbon dioxide separation and recovery facility that separates and recovers carbon dioxide from gas containing carbon dioxide,
Renewable energy power generation equipment and
A water electrolysis facility that electrolyzes water to generate hydrogen using the electric power obtained from the renewable energy power generation facility, and a water electrolysis facility.
A metanation facility having a metanation reactor that produces methane using the carbon dioxide and the hydrogen is provided.
A hydrogen storage means for storing the hydrogen generated in the water electrolysis facility, and
A carbon dioxide storage means for storing the carbon dioxide recovered by the carbon dioxide separation and storage facility is further provided.
The filling rate of the hydrogen in the hydrogen storage means and the filling rate of the carbon dioxide in the carbon dioxide storage means are adjusted to be within a predetermined range, and the filling rate of the hydrogen and the carbon dioxide is a predetermined value. In the above cases, an effective utilization system of recovered carbon dioxide having a configuration for adjusting the hydrogen and the carbon dioxide to be supplied to the metanation reactor. The hydrogen storage means includes a hydrogen storage tank or a canister containing a hydrogen storage alloy.
The effective utilization system for recovered carbon dioxide according to claim 1, wherein the carbon dioxide storage means includes a carbon dioxide storage tank. A hydrogen flow rate adjusting valve and a hydrogen flow meter are installed between the hydrogen storage means and the methanation reactor.
A carbon dioxide flow control valve and a carbon dioxide flow meter are installed between the carbon dioxide storage means and the metanation reactor.
The recovered carbon dioxide according to claim 1 or 2, which has a configuration for adjusting the flow rates of the hydrogen and the carbon dioxide supplied to the metanation reactor by using the hydrogen flow rate adjusting valve and the carbon dioxide flow rate adjusting valve. Effective utilization system. A hydrogen filling amount measuring means is installed in the hydrogen storage means, and the hydrogen filling amount measuring means is installed.
A carbon dioxide filling amount measuring means is installed in the carbon dioxide storage means, and the carbon dioxide filling amount measuring means is installed.
The first threshold value of the hydrogen, the second threshold value of the hydrogen, and the third threshold value of the hydrogen are set in descending order of the value of the filling rate of the hydrogen calculated from the filling amount of the hydrogen measured by the hydrogen filling amount measuring means. Set,
The first threshold value of the carbon dioxide, the second threshold value of the carbon dioxide, and the carbon dioxide in descending order of the value of the filling rate of the carbon dioxide calculated from the filling amount of the carbon dioxide measured by the carbon dioxide filling amount measuring means. Set a third threshold for carbon and
When the filling rate of the hydrogen is equal to or higher than the second threshold value of the hydrogen and the filling rate of the carbon dioxide is equal to or higher than the second threshold value of the carbon dioxide, the hydrogen and the carbon dioxide are used. The hydrogen flow rate adjusting valve and the carbon dioxide flow rate adjusting valve were opened so as to supply to the methanation reactor.
When the filling rate of the hydrogen is equal to or less than the third threshold value of the hydrogen or the filling rate of the carbon dioxide is equal to or lower than the third threshold value of the carbon dioxide, the hydrogen and the carbon dioxide to the metanation reactor are formed. The effective utilization system for recovered carbon dioxide according to claim 3, further comprising a configuration in which the hydrogen flow rate adjusting valve and the carbon dioxide flow rate adjusting valve are closed so as to stop the supply of carbon. When the filling rate of the hydrogen is equal to or higher than the first threshold value of the hydrogen, the supply of the hydrogen to the hydrogen storage means is stopped.
The effective utilization system for recovered carbon dioxide according to claim 4, further comprising a configuration in which the supply of the hydrogen to the hydrogen storage means is started when the filling rate of the hydrogen is less than the second threshold value. When the filling rate of the carbon dioxide is equal to or higher than the first threshold value of the carbon dioxide, the supply of the carbon dioxide to the carbon dioxide storage means is stopped.
The recovered carbon dioxide according to claim 5, wherein when the filling rate of the carbon dioxide is less than the second threshold value of the carbon dioxide, the supply of the carbon dioxide to the carbon dioxide storage means is started. Effective utilization system. With more monitors
The monitor displays the change over time of the filling rate of hydrogen and the filling rate of carbon dioxide, the first threshold value of hydrogen, the second threshold value of hydrogen, and the third threshold value of hydrogen in one graph. The effective utilization system of recovered carbon dioxide according to claim 6 to be displayed. A plurality of the metanation reactors are installed.
Reaction gas shutoff valves are installed on all upstream sides of the plurality of the metanational reactors.
Carbon dioxide concentration measuring means are installed on all downstream sides of the plurality of the metanation reactors.
A threshold concentration is set for the carbon dioxide outlet concentration measured by the carbon dioxide concentration measuring means, and the threshold concentration is set.
For the metanation reactor in which the outlet concentration of carbon dioxide exceeds the threshold concentration, the reaction gas shutoff valve of the metanation reactor is closed.
The opening degree of the hydrogen flow rate adjusting valve and the opening degree of the carbon dioxide flow rate adjusting valve are adjusted so that the supply amounts of the hydrogen and the carbon dioxide correspond to the metanation reactor in which the reaction gas shutoff valve is open. The effective utilization system of recovered carbon dioxide according to any one of claims 3 to 6, which has a configuration for With more monitors
The effective utilization system for recovered carbon dioxide according to claim 8, wherein the monitor displays the outlet concentration and the threshold concentration of the carbon dioxide on one graph. With more control devices
Any of claims 1 to 9, wherein the control device adjusts the filling rate of the hydrogen and the filling rate of the carbon dioxide, and adjusts the supply of the hydrogen and the carbon dioxide to the methanation reactor. The effective utilization system of recovered carbon dioxide described in item 1. A carbon dioxide separation and recovery process that separates and recovers carbon dioxide from gas containing carbon dioxide,
Renewable energy power generation process that generates electricity from renewable energy,
A water electrolysis step of electrolyzing water to generate hydrogen using the electric power obtained in the renewable energy power generation step, and a water electrolysis step.
A metanation step of producing methane using the carbon dioxide and the hydrogen, and
A hydrogen storage step for storing the hydrogen obtained in the water electrolysis step, and a hydrogen storage step.
The carbon dioxide storage step of storing the carbon dioxide obtained in the carbon dioxide separation and storage step is included.
The hydrogen filling rate in the hydrogen storage step and the carbon dioxide filling rate in the carbon dioxide storage step are adjusted so as to be within a predetermined range, and the filling rate of the hydrogen and the carbon dioxide is a predetermined value. In the above case, a method for utilizing recovered carbon dioxide, which comprises a step of adjusting the metanation step to supply the hydrogen and the carbon dioxide. The carbon dioxide storage means is one carbon dioxide storage tank.
A carbon dioxide filling amount measuring means is installed in the carbon dioxide storage means, and the carbon dioxide filling amount measuring means is installed.
The first threshold value of the carbon dioxide, the second threshold value of the carbon dioxide, and the carbon dioxide in descending order of the value of the filling rate of the carbon dioxide calculated from the filling amount of the carbon dioxide measured by the carbon dioxide filling amount measuring means. Set a third threshold for carbon and
When the filling rate of the carbon dioxide is equal to or higher than the first threshold value of the carbon dioxide, the filling of the carbon dioxide into the carbon dioxide storage tank is stopped, and the filling rate of the carbon dioxide is said to be the carbon dioxide. The stop of the filling is held until the temperature drops to the second threshold, and when the filling rate of the carbon dioxide becomes equal to or lower than the second threshold of the carbon dioxide, the filling of the carbon dioxide is restarted.
Further, when the filling rate of the carbon dioxide becomes equal to or lower than the third threshold value of the carbon dioxide, the release of carbon dioxide from the carbon dioxide storage tank is stopped, and the filling rate of the carbon dioxide becomes the carbon dioxide. The release of the carbon dioxide is maintained until the second threshold is increased, and when the filling rate of the carbon dioxide becomes equal to or less than the second threshold of the carbon dioxide, the release of the carbon dioxide is restarted. 1. Effective utilization system of recovered carbon dioxide according to 1. The hydrogen storage means is one hydrogen storage tank.
A hydrogen filling amount measuring means is installed in the hydrogen storage means, and the hydrogen filling amount measuring means is installed.
The first threshold value of the hydrogen, the second threshold value of the hydrogen, and the third threshold value of the hydrogen are set in descending order of the value of the filling rate of the hydrogen calculated from the filling amount of the hydrogen measured by the hydrogen filling amount measuring means. Set,
When the filling rate of the hydrogen is equal to or higher than the first threshold value of the hydrogen, the filling of the hydrogen into the hydrogen storage means is stopped, and the filling rate of the hydrogen is lowered to the second threshold value of the hydrogen. The filling is held stopped until the hydrogen is filled, and when the filling rate of the hydrogen becomes equal to or lower than the second threshold value of the hydrogen, the filling of the hydrogen is restarted.
Further, when the filling rate of the hydrogen becomes equal to or lower than the third threshold value of the hydrogen, the release of hydrogen from the hydrogen storage means is stopped, and the filling rate of the hydrogen reaches the second threshold value of the hydrogen. Effective utilization of the recovered carbon dioxide according to claim 1, which holds the stop of the release until the increase, and restarts the release of the hydrogen when the filling rate of the hydrogen becomes equal to or lower than the second threshold value of the hydrogen. system. The hydrogen storage means includes a plurality of hydrogen storage tanks or a plurality of canisters containing a hydrogen storage alloy.
The hydrogen storage means has a switching valve and has a switching valve.
The recovery according to claim 1, wherein the switching valve is operated so that one of the plurality of hydrogen storage tanks or canisters is used for storing the hydrogen and the other is used for releasing the hydrogen. Effective use system of carbon dioxide. The hydrogen storage means includes a plurality of hydrogen storage tanks or a plurality of canisters containing a hydrogen storage alloy.
The hydrogen storage means has a switching valve and has a switching valve.
12. Recovery according to claim 12, wherein the switching valve is operated so that one of the plurality of hydrogen storage tanks or canisters is used for storing the hydrogen and the other is used for releasing the hydrogen. Effective use system of carbon dioxide. The recovery according to claim 1, wherein the metanation reactor contains a solid catalyst using an inorganic material that produces methane from carbon dioxide and hydrogen, or a metanation catalyst containing a biocatalyst using bacteria. Effective use system of carbon dioxide. The effective utilization system for recovered carbon dioxide according to claim 1, wherein the flow rate of carbon dioxide and the flow rate of hydrogen supplied to the metanation reactor can be adjusted, respectively. The metanation equipment includes a plurality of the metanation reactors.
On the downstream side of each of the methane reactors, means for measuring the concentration of carbon dioxide, hydrogen or methane is provided.
The effective utilization system for recovered carbon dioxide according to claim 16, wherein deterioration of the metanation catalyst is detected by using the measured value of the concentration. When the deterioration of the metanation catalyst is detected, the supply of carbon dioxide and hydrogen to the metanation reactor in which the deterioration is detected is stopped, and the carbon dioxide and hydrogen flowing into the metanation reactor are stopped. The effective utilization system for recovered carbon dioxide according to claim 18, wherein the flow rate obtained by subtracting the flow rate is supplied to the metanation facility. The effective utilization system of recovered carbon dioxide according to claim 1, the carbon dioxide storage means is one carbon dioxide storage tank, and the carbon dioxide filling amount measuring means is installed in the carbon dioxide storage means. It ’s a way to control things,
The first threshold value of the carbon dioxide, the second threshold value of the carbon dioxide, and the carbon dioxide in descending order of the value of the filling rate of the carbon dioxide calculated from the filling amount of the carbon dioxide measured by the carbon dioxide filling amount measuring means. Set a third threshold for carbon and
When the filling rate of the carbon dioxide is equal to or higher than the first threshold value of the carbon dioxide, the filling of the carbon dioxide into the carbon dioxide storage tank is stopped, and the filling rate of the carbon dioxide is said to be the carbon dioxide. The stop of the filling is held until the temperature drops to the second threshold, and when the filling rate of the carbon dioxide becomes equal to or lower than the second threshold of the carbon dioxide, the filling of the carbon dioxide is restarted.
Further, when the filling rate of the carbon dioxide becomes equal to or lower than the third threshold value of the carbon dioxide, the release of carbon dioxide from the carbon dioxide storage tank is stopped, and the filling rate of the carbon dioxide becomes the carbon dioxide. The recovery of carbon dioxide is maintained until it increases to the second threshold value, and when the filling rate of the carbon dioxide becomes equal to or less than the second threshold value of the carbon dioxide, the release of the carbon dioxide is restarted. How to control an effective carbon utilization system. The effective utilization system for recovered carbon dioxide according to claim 1, wherein the hydrogen storage means is one hydrogen storage tank, and the hydrogen storage means is provided with a hydrogen filling amount measuring means.
It ’s a way to control what
The first threshold value of the hydrogen, the second threshold value of the hydrogen, and the third threshold value of the hydrogen are set in descending order of the value of the filling rate of the hydrogen calculated from the filling amount of the hydrogen measured by the hydrogen filling amount measuring means. Set,
When the filling rate of the hydrogen is equal to or higher than the first threshold value of the hydrogen, the filling of the hydrogen into the hydrogen storage means is stopped, and the filling rate of the hydrogen is lowered to the second threshold value of the hydrogen. The filling is held stopped until the hydrogen is filled, and when the filling rate of the hydrogen becomes equal to or lower than the second threshold value of the hydrogen, the filling of the hydrogen is restarted.
Further, when the filling rate of the hydrogen becomes equal to or lower than the third threshold value of the hydrogen, the release of hydrogen from the hydrogen storage means is stopped, and the filling rate of the hydrogen reaches the second threshold value of the hydrogen. A method for controlling an effective utilization system of recovered carbon dioxide, which keeps the release stopped until the amount increases, and restarts the release of the hydrogen when the filling rate of the hydrogen becomes equal to or less than the second threshold value of the hydrogen. A display device used in the effective utilization system of recovered carbon dioxide according to claim 1.
The time course of the filling rate or filling amount of each of the carbon dioxide storage means and the hydrogen storage means is displayed in a graph.
Further, a display device that displays the threshold values of the carbon dioxide storage means and the hydrogen storage means on the graph. 22. The display device according to claim 22, which displays the charge and release states of the carbon dioxide storage means and the hydrogen storage means on the same screen.

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