Control device, fuel production system, control method, and control program

Abstract

To provide a control device, a fuel production system, a control method, and a control program capable of optimizing the whole elements related to a plant.SOLUTION: The control device 50 includes a comparison part 52 for determining a fuel production amount as a production amount of fuel and a carbon dioxide storage amount as a storage amount of carbon dioxide based on a result of comparison between an economic effect based on reduction of carbon dioxide when the fuel is produced in the fuel production system and an economic effect when the carbon dioxide is stored.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to a control device, a fuel production system, a control method, and a control program. [Background technology]

[0002] Toward the realization of a carbon-neutral society, there is a growing need to produce low-carbon fuels, particularly sustainable aviation fuel (SAF) in the aviation industry. For example, Patent Document 1 discloses the production of hydrocarbon fuel by synthesizing carbon dioxide recovered from exhaust gases of a power plant with hydrogen obtained by a water electrolysis device. Patent Document 1 also discloses that the power supplied to the water electrolysis device can be selected from renewable energy power generation devices, etc., based on factors such as the level of electricity costs. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2020-45430 Summary of the Invention [Problem to be solved by the invention]

[0004] At power plants, carbon dioxide emissions are also stored. Meanwhile, the invention of Patent Document 1 simply selects the electricity to be supplied to the water electrolysis device based on factors such as the cost of electricity, without considering the value associated with storing or reducing carbon dioxide. Even if a decision is made based on the price of renewable energy electricity and the amount of electricity that can be supplied, there is a limit to the amount of synthetic fuels and other resources that can actually be recycled. Taking this into account, it is necessary to calculate costs comprehensively and optimize the operation of the combustion production system, including the power generation process and fuel production process.

[0005] The present disclosure has been made in consideration of the above circumstances, and aims to provide a control device, a fuel production system, a control method, and a control program that are capable of optimizing operation by taking into account all elements involved in the system. [Means for solving the problem]

[0006] In order to solve the above problems, the control device, fuel production system, control method, and control program of the present disclosure employ the following means. The control device of the present disclosure includes a comparison unit that determines the fuel production amount, which is the amount of fuel produced, and the carbon dioxide storage amount, which is the amount of carbon dioxide stored, based on the results of comparing the economic effect of reducing carbon dioxide when producing fuel in a fuel production system with the economic effect of storing the carbon dioxide.

[0007] The fuel production system of the present disclosure includes the above-described control device.

[0008] The control method disclosed herein includes a comparison step, executed by a computer, of determining a fuel production volume, which is the amount of fuel produced, and a carbon dioxide storage volume, which is the amount of carbon dioxide stored, based on the results of comparing the economic effect of reducing carbon dioxide when producing fuel in a fuel production system with the economic effect of storing the carbon dioxide.

[0009] The control program of the present disclosure causes a computer to execute the above-described control method. [Effects of the Invention]

[0010] According to the present disclosure, it is possible to optimize the control of the fuel production system so as to achieve the most economical effect depending on the operating conditions of the system. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 illustrates an overview of a fuel production system according to some embodiments of the present disclosure. [Figure 2]FIG. 2 is a diagram illustrating an example of a hardware configuration of a control device according to some embodiments of the present disclosure. [Figure 3] FIG. 2 illustrates an example of the functionality of a control device in some embodiments of the present disclosure. [Figure 4] FIG. 10 is a diagram illustrating an example of a control flow of a control device according to some embodiments of the present disclosure. [Figure 5] FIG. 10 is a diagram showing a list of control results of a control device according to some embodiments of the present disclosure. [Figure 6] FIG. 1 is a diagram illustrating an overview of a first modified example of a fuel production system according to some embodiments of the present disclosure. [Figure 7] FIG. 10 is a diagram illustrating an overview of a second modified example of a fuel production system according to some embodiments of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, an embodiment of a control device, a fuel production system, a control method, and a control program according to the present disclosure will be described with reference to the drawings. FIG. 1 is a diagram illustrating an overview of a fuel production system according to some embodiments of the present disclosure. The fuel production system 1 in Figure 1 includes a power generation facility 10, a first CO2 recovery device 20, a water electrolysis device (electrolysis device) 30, a reverse shift reactor 40, a second CO2 recovery device 60, a fuel synthesis device 70, a chimney 80, and a control device 50.

[0013] The power generation facility 10 is a facility that generates electricity, and is, for example, a thermal power generation facility including a boiler that uses biomass as fuel. The fuel input to the power generation facility 10 of the present disclosure is biomass. A portion of the electricity generated by the power generation facility 10 is supplied to a water electrolysis device 30. In addition, a portion of the electricity generated by the power generation facility 10 is sold as electricity for sale. Exhaust gas emitted during power generation by the power generation facility 10 is discharged to a first CO2 recovery device 20.

[0014] The first CO2 recovery unit 20 recovers at least a portion of the carbon dioxide (CO2) in the flue gas discharged from the power generation facility 10. The recovered carbon dioxide is sent to the reverse shift reactor 40. The flue gas containing carbon dioxide that was not recovered by the first CO2 recovery unit 20 is released into the atmosphere from a chimney 80.

[0015] The water electrolysis device 30 electrolyzes water or water vapor using power from the power generation facility 10 and / or external power supplied from an external source to produce hydrogen (H2) and oxygen (O2). The fuel production system 1 may also include an H2 tank (not shown) for storing the hydrogen produced by the water electrolysis device 30. In the fuel production system 1 of the present disclosure, the external power must be electricity derived from renewable energy, particularly green electricity, so that the fuel can be certified as SAF. The oxygen produced by the water electrolysis device 30 may be supplied to the power generation facility 10 as an oxidizing gas for combustion.

[0016] The reverse shift reactor 40 uses a reverse shift reaction to produce carbon monoxide (CO) and water (HO) from the carbon dioxide recovered in the first CO2 recovery unit and the hydrogen produced in the water electrolysis unit 30. The produced carbon monoxide and water are sent to the second CO2 recovery unit 60 together with the carbon dioxide.

[0017] The second CO2 recovery unit 60 recovers at least a portion of the carbon dioxide (CO2) from the carbon monoxide, water, and carbon dioxide from the reverse shift reactor 40. The recovered carbon dioxide is stored in a carbon dioxide storage facility (not shown). A portion of the carbon dioxide recovered by the second CO2 recovery unit 60 may be sent back to the reverse shift reactor 40.

[0018] The fuel synthesis unit 70 is a unit that synthesizes liquefied hydrocarbons using, for example, the Fischer-Tropsch process. The FT process is a series of processes that synthesize liquefied hydrocarbons from carbon monoxide and hydrogen using a catalytic reaction, and iron or cobalt compounds are generally used as catalysts. The FT process aims to produce synthetic oils and synthetic fuels (SAF, naphtha, etc.) that can be used as substitutes for petroleum. In the present disclosure, liquefied hydrocarbons (CnH2n+2) are synthesized from hydrogen produced by the water electrolysis unit 30 and carbon dioxide emitted from the power generation facility 10 via a reverse shift reactor 40.

[0019] The control device 50 controls the fuel production system 1 .

[0020] Carbon dioxide is stored in the fuel production system 1. Carbon dioxide storage generates carbon credits (value associated with the amount of fixed carbon) according to the amount stored, creating value other than resource utilization. In addition, the amount of fuel that can be produced by the fuel production system 1 may be limited by the electricity price (electricity bill, power purchase price, power sale price) of renewable energy-derived electricity used as external power, and the external power procurement amount, which is the amount of external power that can be procured. The control device 50 takes these factors into consideration when optimizing the fuel production system 1.

[0021] In this way, the control device 50 of the present disclosure performs an evaluation using LCA (Life Cycle Assessment, a method of calculating environmental loads such as carbon dioxide emissions over the entire life cycle of a product or service (raw material procurement, manufacturing, use, disposal / recycling) and quantitatively evaluating the impact on the environment).

[0022] FIG. 2 is a diagram illustrating an example of a hardware configuration of a control device according to some embodiments of the present disclosure. 2, the controller 50 is a computer system including, for example, a CPU (Central Processing Unit: processor) 1100, a secondary storage device (ROM, Secondary storage: memory) 1200, a main storage device (RAM, Main Memory) 1300, a hard disk drive (HDD) 1400 as a large-capacity storage device, and a communication unit 1500 for connecting to a network or the like. Note that a solid-state drive (SSD) may also be used as the large-capacity storage device. These units are connected via a bus 1800.

[0023] The CPU 1100 controls the entire control device 50 using, for example, an operating system (OS) stored in a secondary storage device 1200 connected via a bus 1800, and executes various processes by executing various programs stored in the secondary storage device 1200. One or more CPUs 1100 may be provided, and may implement processes in cooperation with each other.

[0024] The main memory device 1300 is composed of writable memory such as cache memory, RAM (Random Access Memory), etc., and is used as a working area for reading out programs executed by the CPU 1100 and writing data processed by the programs.

[0025] The secondary storage device 1200 is a non-transitory computer-readable storage medium. Examples of the secondary storage device 1200 include a magnetic disk, a magneto-optical disk, a CD-ROM, a DVD-ROM, and a semiconductor memory. Examples of the secondary storage device 1200 include a read-only memory (ROM), a hard disk drive (HDD), and a solid-state drive (SSD) flash memory. The secondary storage device 1200 stores, for example, an operating system (OS) for controlling the entire information processing device, such as Windows (registered trademark), iOS (registered trademark), or Android (registered trademark), a basic input / output system (BIOS), various device drivers for operating peripheral devices, various application software, and various data and files. The secondary storage device 1200 also stores programs for implementing various processes and various data required for implementing the various processes. A plurality of secondary storage devices 1200 may be provided, and the above-described programs and data may be stored separately in each secondary storage device 1200.

[0026] The control device 50 may also include an input unit such as a keyboard or mouse, a display unit such as a liquid crystal display device that displays data, etc. The control device 50 may also include a notification unit such as a display unit, a lamp, or a speaker that outputs sound, especially an alarm sound.

[0027] FIG. 3 is a diagram illustrating an example of the functionality of a control device in some embodiments of the present disclosure. 3, the control device 50 includes a comparison unit 52. The control device 50 may also include a calculation unit 51 and a prediction unit 53.

[0028] A series of processes for realizing the functions of the control device 50 is stored in the form of a program in, for example, the secondary storage device 1200 (see FIG. 2), and the CPU (processor) 1100 (see FIG. 2) reads this program into the main storage device 1300 (see FIG. 2) and executes information processing and arithmetic processing to realize various functions. Note that the program may be pre-installed in the secondary storage device 1200, provided in a state stored in another non-transitory computer-readable storage medium, or distributed via wired or wireless communication means. Examples of non-transitory computer-readable storage media include magnetic disks, magneto-optical disks, CD-ROMs, DVD-ROMs, and semiconductor memories.

[0029] 3 calculates the economic effect based on the reduction of carbon dioxide and the economic effect due to the amount of carbon dioxide stored. The economic effect based on the reduction of carbon dioxide is calculated based on the amount of carbon dioxide reduced per unit amount of fuel produced by the fuel production system 1. The economic effect due to the amount of carbon dioxide stored is calculated based on the market price of carbon credits when the fuel production system 1 is in operation.

[0030] The economic effect based on carbon dioxide reduction is calculated using, for example, the value of carbon dioxide reduction per unit amount of SAF fuel that is expected to be certified under the CORSIA (Carbon Offsetting and Reduction Scheme for International Aviation) system, but other methods may also be used as appropriate.

[0031] The economic effect of carbon dioxide storage is calculated, for example, using the market price of carbon credits, which are securitized carbon dioxide reductions or absorptions that can be traded, but other methods may also be used as appropriate.

[0032] The calculation unit 51 acquires data from each unit of the fuel production system 1 and performs calculations.

[0033] The comparison unit 52 compares the economic effect based on the carbon dioxide reduction calculated by the calculation unit 51 with the economic effect based on the carbon dioxide storage amount. Based on the comparison result, the comparison unit 52 determines the fuel production amount, which is the amount of fuel produced in the fuel production system 1, and the carbon dioxide storage amount, which is the amount of carbon dioxide stored. Specifically, for carbon dioxide sent from the first CO2 recovery unit 20 and the second CO2 recovery unit 60, the comparison unit 52 determines the ratio between the amount sent to the reverse shift reactor 40 and the amount sent to the carbon dioxide storage facility.

[0034] When the fuel production system 1 purchases external electricity, the comparison unit 52 may determine the amount of fuel produced and the amount of carbon dioxide stored based on the electricity purchase price derived from the electricity purchase price and the amount of electricity purchased in addition to the above-mentioned comparison result.

[0035] When there is a constraint on the amount of external electricity procured, the comparison unit 52 may determine the amount of fuel produced and the amount of carbon dioxide stored based on the amount of external electricity procured in addition to the above-mentioned comparison result and the electricity purchase price.

[0036] The prediction unit 53 predicts future values ​​based on trends in fluctuating electricity charges (power purchase price, power sale price), the amount of external electricity procurement, the market price of carbon credits, etc. The prediction unit 53 may perform machine learning on values ​​such as the electricity charges (power purchase price, power sale price), the amount of external electricity procurement, and the market price of carbon credits to make predictions. The predicted values ​​are passed to the comparison unit 52, which determines the amount of fuel production and the amount of carbon dioxide storage based on the predicted values.

[0037] FIG. 4 is a diagram illustrating an example of a control flow of a control device according to some embodiments of the present disclosure. In step S101, the comparison unit 52 of the control device 50 determines whether the electricity cost is lower than a threshold value. In the present disclosure, the electricity cost is the unit price of purchasing and selling electricity of external electricity derived from renewable energy. The electricity cost may also be the purchasing price and selling price calculated from the unit price of purchasing and selling electricity of external electricity. The threshold value is a predetermined value, and is a value that is arbitrarily set based on, for example, the operating status of the fuel production system 1. In step S101, if it is determined that the electricity cost is lower than the threshold value (low price), the process proceeds to step S102. On the other hand, if it is determined that the electricity cost is equal to or higher than the threshold value (high price), the process proceeds to step S107.

[0038] If it is determined that the electricity fee is lower than the threshold value (YES in S101), the comparison unit 52 determines whether the amount of external power procurement is less than the threshold value. The amount of external power procurement can fluctuate greatly because external power is renewable energy. The threshold value is a predetermined value that is arbitrarily set based on the amount of power required when all of the amount of carbon dioxide recovered in the fuel production system 1 and the amount of carbon dioxide recycled within the fuel production system 1 are used for fuel production. If it is determined in step S102 that the amount of external power procurement is less than the threshold value (small), the process proceeds to step S103. On the other hand, if it is determined that the amount of external power procurement is equal to or greater than the threshold value (ample), the process proceeds to step S104.

[0039] If it is determined that the amount of external electricity procured is less than the threshold (YES in S102), the comparison unit 52 varies the amount of fuel production in proportion to the amount of external electricity procured (S103). If there are restrictions on the amount of external electricity procured even if the electricity rate is low, the comparison unit 52 determines the ratio of the amount of fuel production and the amount of carbon dioxide stored according to the amount of external electricity procured.

[0040] If it is determined that the amount of external electricity procurement is equal to or greater than the threshold (NO in S102), the comparison unit 52 determines whether the value of carbon dioxide reduction is large (S104). The value of carbon dioxide reduction is determined based on the results of comparing the economic effect based on carbon dioxide reduction and the economic effect of the amount of carbon dioxide storage. If the economic effect based on carbon dioxide reduction is greater than the economic effect of the amount of carbon dioxide storage, it is determined that the value of carbon dioxide reduction is large, and the process proceeds to step S105. On the other hand, if the economic effect based on carbon dioxide reduction is not greater (smaller) than the economic effect of the amount of carbon dioxide storage, it is determined that the value of carbon dioxide reduction is small, and the process proceeds to step S106.

[0041] Since the majority of fuel production costs are electricity costs, when electricity costs are low and there are no constraints on the amount of external electricity procurement (when transitioning to S104), the fuel production costs of fuel production system 1 fluctuate little depending on whether or not carbon dioxide is stored, so the ratio of fuel production volume to carbon dioxide storage volume is determined based on the value of carbon dioxide reduction.

[0042] Here, if the amount of carbon dioxide storage increases, the amount of fuel production decreases. If the amount of fuel production decreases, the amount of carbon dioxide reduction per unit of fuel increases, and the value of carbon dioxide reduction increases. Conversely, if the amount of carbon dioxide storage decreases, the amount of fuel production increases. If the amount of fuel production increases, the amount of carbon dioxide reduction per unit of fuel decreases, and the value of carbon dioxide reduction decreases.

[0043] If it is determined that the value of carbon dioxide reduction is large (YES in S104), the comparison unit 52 increases the amount of carbon dioxide stored and decreases the amount of fuel produced (S105). This increases the amount of carbon dioxide reduction per unit amount of fuel, and makes it possible to increase the value of carbon dioxide reduction.

[0044] On the other hand, if it is determined that the value of carbon dioxide reduction is small (NO in S104), the comparison unit 52 decreases the amount of carbon dioxide stored and increases the amount of fuel produced (S106).

[0045] In step S101, if it is determined that the electricity cost is equal to or greater than the threshold (expensive), the comparison unit 52 increases the amount of carbon dioxide stored and reduces the amount of fuel produced (S107). If the electricity cost is high (NO in S101), the amount of carbon dioxide stored is increased and the amount of fuel produced is reduced, thereby reducing the amount of power used by the fuel production system 1. This reduces fuel production costs and increases the value of carbon dioxide reduction.

[0046] FIG. 5 is a diagram showing a list of control results of the control device in some embodiments of the present disclosure. As shown in FIG. 5, the control by the control device 50 is divided into eight cases depending on the electricity cost, the amount of external power procurement (electricity amount), and the value of carbon dioxide reduction (CO2 reduction amount evaluation).

[0047] Case 1 is a case where electricity prices are low, external power procurement is abundant, and the value of carbon dioxide reduction is high. This corresponds to step S105 in FIG. 4, and increases the amount of carbon dioxide stored and decreases the amount of fuel produced. Case 2 is a case where electricity prices are low, external power procurement is abundant, and the value of carbon dioxide reduction is small. This corresponds to step S106 in Figure 4, and the amount of carbon dioxide stored is reduced and the amount of fuel produced is increased. Cases 3 and 4 are cases where electricity prices are low and the amount of external electricity procured is small, and correspond to step S103 in Figure 4, and the amount of fuel produced is varied in proportion to the amount of external electricity procured, regardless of the value of carbon dioxide reduction. Cases 5 to 8 are cases where electricity prices are high, which corresponds to step S107 in Figure 4, and increase the amount of carbon dioxide stored and decrease the amount of fuel produced regardless of the amount of external electricity procured and the value of carbon dioxide reduction.

[0048] In this disclosure, the amount of carbon dioxide stored is defined as the amount of carbon dioxide recovered from the inlet of the fuel synthesis unit 70 in accordance with CORSIA regulations, i.e., the amount of carbon dioxide captured by the second CO2 capture unit 60 and sent to the carbon dioxide storage facility.

[0049] Here, if the fuel produced by the fuel production system 1 is e-fuel (a general-purpose low-carbon synthetic fuel) rather than SAF that meets the CORSIA regulations, the carbon dioxide to be stored may include carbon dioxide recovered by the first CO2 recovery device 20 from the exhaust gas of the power generation equipment 10.

[0050] If the carbon dioxide captured by the first CO2 capture unit 20 from the exhaust gas of the power generation facility 10 is sent to the carbon dioxide storage facility, the carbon dioxide storage rate can be any value between 0% and 100%. When the carbon dioxide storage rate is 100%, it becomes BECCS (Bio-energy with Carbon dioxide Capture and Storage, a technology that captures and stores carbon dioxide generated by the combustion of biomass), and all of the carbon dioxide captured by the first CO2 capture unit 20 from the exhaust gas of the power generation facility 10 is stored.

[0051] As mentioned above, in order to be certified as SAF, the external electricity must be green electricity, but there are various other regulations as well. Therefore, it is possible that one of the regulations is not met and SAF certification cannot be obtained, but in this case it is possible to convert to e-fuel. Even if e-fuel is used, it is possible to compare and optimize the value of carbon dioxide reduction.

[0052] In this disclosure, only carbon dioxide storage has been described as a method of carbon fixation, but in addition to storage, carbon dioxide may also be used as a resource for fuel, fertilizer, etc., so-called CCUS (Carbon dioxide Capture, Utilization and Storage). In this case, the ratio or amount of carbon dioxide used as a resource is also optimized.

[0053] <Variation 1> FIG. 6 is a diagram illustrating an overview of a first modification of a fuel production system according to some embodiments of the present disclosure. The fuel production system 1a in Fig. 6 includes a co-electrolysis device 90 instead of the water electrolysis device 30 and the reverse shift reactor 40 of the fuel production system 1 in Fig. 1. In other respects, it is the same as the fuel production system 1 in Fig. 1. Therefore, the same reference numerals are used for the same components, and the description thereof will be omitted.

[0054] The co-electrolysis device 90 is a device that electrolyzes water vapor (H2O) together with CO2 using electric power (co-electrolysis). The co-electrolysis device 90 electrolyzes water and steam using electric power from the power generation facility 10 and / or external electric power supplied from an external source, to generate hydrogen (H2), carbon monoxide (CO), and oxygen (O2). The generated hydrogen and carbon monoxide are sent to the fuel synthesis device 70 via the second CO2 capture device 60. The oxygen generated in the co-electrolysis device 90 may be supplied to the power generation facility 10 as an oxidizing gas for combustion.

[0055] In the fuel production system 1a, the control device 50 optimizes the amount of carbon dioxide stored and sent to the carbon dioxide storage facility for carbon dioxide recovered by the second CO2 recovery device 60 and the amount of carbon dioxide used for fuel production (specifically, the amount of carbon dioxide sent to the co-electrolysis device 90).

[0056] <Variation 2> FIG. 7 is a diagram illustrating an overview of a second modification of a fuel production system according to some embodiments of the present disclosure. The fuel production system 1b in Fig. 7 includes a DAC (Direct Air Capture, an atmospheric carbon dioxide capture device) 100 instead of the power generation equipment 10 and the first CO2 capture device 20 of the fuel production system 1a in Fig. 6. In other respects, it is the same as the fuel production system 1a in Fig. 6. Therefore, the same reference numerals are used for the same components, and the description thereof will be omitted.

[0057] The DAC 100 is a device that directly captures carbon dioxide from the atmosphere. The DAC 100 captures carbon dioxide from the atmosphere using the atmosphere and external power supplied from an external source. The captured carbon dioxide is sent to the co-electrolysis device 90. Gases other than the captured carbon dioxide are discharged from the chimney 80.

[0058] In the fuel production system 1b, the control device 50 optimizes the amount of carbon dioxide stored and sent to the carbon dioxide storage facility for carbon dioxide captured by the second CO2 capture device 60 and the amount of carbon dioxide used for fuel production (specifically, the amount of carbon dioxide sent to the co-electrolysis device 90).

[0059] <Additional Notes> The control device, fuel production system, control method, and control program described in the above-described embodiments can be understood, for example, as follows.

[0060] The control device (50) of the first aspect of the present disclosure includes a comparison unit (52) that determines a fuel production amount, which is the amount of fuel produced, and a carbon dioxide storage amount, which is the amount of carbon dioxide stored, based on a result of comparing the economic effect of reducing carbon dioxide when producing fuel in the fuel production system (1) with the economic effect of storing the carbon dioxide.

[0061] In the fuel production system, the economic effects of fuel production and carbon dioxide storage are compared, and the amount of fuel produced and the amount of carbon dioxide stored are determined. This allows the system control to be optimized to achieve the greatest economic effect depending on the conditions under which the fuel production system is operating.

[0062] The control device according to a second aspect of the present disclosure may be configured in the first aspect, further comprising a calculation unit (51) that calculates the economic effect of the carbon dioxide storage amount based on the market price of carbon credits.

[0063] Depending on the market price of carbon credits when the fuel production system is in operation, the economic effect of carbon dioxide storage can be calculated and system control can be optimized.

[0064] The control device of the third aspect of the present disclosure may be configured in the first or second aspect to include a calculation unit that calculates the economic effect of carbon dioxide reduction through the production of the fuel based on the amount of carbon dioxide reduction per unit amount of the fuel.

[0065] The economic effect of the carbon dioxide reduction can be calculated based on the amount of carbon dioxide reduction per unit amount of fuel when the fuel production system is in operation, and the control of the system can be optimized.

[0066] In the control device of the fourth aspect of the present disclosure, in any one of the first to third aspects, the comparison unit may determine the amount of fuel produced and the amount of carbon dioxide stored based on the unit price of electricity purchased from an external source.

[0067] The amount of fuel produced and the amount of carbon dioxide stored are determined using the unit price of external electricity purchased when the fuel production system is in operation, allowing for more accurate determinations based on system operation, which in turn allows for more accurate calculations of economic benefits.

[0068] In the control device of a fifth aspect of the present disclosure, in any of the first to fourth aspects, the comparison unit may determine the amount of fuel produced and the amount of carbon dioxide stored based on an external power procurement amount, which is the amount of external power that can be procured.

[0069] Since the amount of fuel production and carbon dioxide storage is determined using the external power procurement amount, which is the amount of external power that can be procured, more accurate determinations can be made based on the amount of power that can be procured, which allows for more accurate calculations of economic benefits.

[0070] In a sixth aspect of the control device of the present disclosure, in any one of the first to fifth aspects, the amount of stored carbon dioxide may be an amount obtained by subtracting an amount of carbon dioxide supplied to the electrolysis device (30) from a total amount of carbon dioxide discharged from a power generation facility (10) of the fuel production system and an amount of carbon dioxide discharged from the electrolysis device (30).

[0071] The control device of the seventh aspect of the present disclosure, in any of the first to sixth aspects, may include a prediction unit (53) that predicts and controls the amount of fuel production and the amount of carbon dioxide storage based on the unit price of selling and purchasing electricity, trends in fluctuations in electricity demand, or machine learning that takes into account the fluctuations.

[0072] By acquiring trends in fluctuations in the electricity selling price, purchasing price, and electricity demand, or by performing machine learning that takes these fluctuations into account, it is possible to make highly accurate predictions of various factors related to the economic effects of the fuel production system, which will further optimize system control.

[0073] A fuel production system according to an eighth aspect of the present disclosure includes the control device according to any one of the first to seventh aspects.

[0074] A control method of a ninth aspect of the present disclosure includes a comparison step executed by a computer, in which a fuel production volume, which is the amount of fuel produced, and a carbon dioxide storage volume, which is the amount of carbon dioxide stored, are determined based on the results of comparing the economic effect based on the reduction in carbon dioxide when producing fuel in a fuel production system with the economic effect when storing the carbon dioxide.

[0075] A control program according to a tenth aspect of the present disclosure causes a computer to execute the control method according to the ninth aspect. [Explanation of symbols]

[0076] 1. Fuel production system 10 Power generation facilities 20. First CO2 capture unit 30 Water electrolysis equipment (electrolysis equipment) 40 Reverse shift reactor 50 Control device 51 Calculation section 52 Comparison section 53 Prediction Department 60 Second CO2 capture device 70 Fuel Synthesizer 80 Chimney 90 Co-electrolyzer 100 DAC (Direct Air Capture, atmospheric carbon dioxide capture device) 1100 CPU 1200 Secondary storage 1300 Main storage 1500 Communications Department 1800 Bus

Claims

1. A control device having a comparison unit that determines the fuel production volume, which is the amount of fuel produced, and the carbon dioxide storage volume, which is the amount of carbon dioxide stored, based on the results of comparing the economic effect of reducing carbon dioxide when producing fuel in a fuel production system with the economic effect of storing the carbon dioxide.

2. The control device according to claim 1 , further comprising a calculation unit that calculates the economic effect of the carbon dioxide storage amount based on the market price of carbon credits.

3. The control device according to claim 1 , further comprising a calculation unit that calculates the economic effect of carbon dioxide reduction resulting from the production of the fuel based on the amount of carbon dioxide reduction per unit amount of the fuel.

4. The control device according to claim 1 , wherein the comparison unit determines the amount of fuel produced and the amount of carbon dioxide stored based on a unit price of electricity purchased from an external source.

5. The control device according to claim 1 , wherein the comparison unit determines the amount of fuel produced and the amount of carbon dioxide stored based on an external power procurement amount that is an amount of external power that can be procured.

6. 2. The control device according to claim 1, wherein the amount of stored carbon dioxide is a sum of the amount of carbon dioxide discharged from a power generation facility of the fuel production system and the amount of carbon dioxide discharged from an electrolysis device, minus the amount of carbon dioxide supplied to the electrolysis device.

7. 2. The control device according to claim 1, further comprising a prediction unit that predicts and controls the amount of fuel produced and the amount of carbon dioxide stored based on the unit price of selling and purchasing electricity, trends in fluctuations in electricity demand, or machine learning that takes into account the fluctuations.

8. A fuel production system comprising the control device according to claim 1.

9. A control method executed by a computer, comprising a comparison step of determining a fuel production volume, which is the amount of fuel produced, and a carbon dioxide storage volume, which is the amount of carbon dioxide stored, based on the results of comparing the economic effect based on the reduction in carbon dioxide when fuel is produced in a fuel production system with the economic effect when the carbon dioxide is stored.

10. A control program for causing a computer to execute the control method according to claim 9.

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