Carbon dioxide fixation system and carbon dioxide fixation method

Abstract

The present invention provides a carbon dioxide fixation method and a carbon dioxide fixation system capable of accurately calculating the amount of carbon dioxide which is fixed. A carbon dioxide fixation system (100) comprises; an electrochemical treatment unit (10) that electrochemically decomposes salt water into an acidic aqueous solution and a basic aqueous solution; a CO2 treatment unit (20) that generates a first aqueous solution by mixing a gas containing CO2 into the basic aqueous solution; a discharge treatment unit (40) that dehydrates the first aqueous solution and generates a carbonate; a first sensor that measures a state value of the carbonate; and a calculation unit (60) that calculates the amount of CO2 which is fixed, on the basis of the state value of the carbonate which has been acquired by the first sensor.

Description

Carbon dioxide sequestration system and carbon dioxide sequestration method

[0001] The present invention relates to a carbon dioxide sequestration system and a carbon dioxide sequestration method.

[0002] To achieve carbon neutrality, negative emission technologies (NETs), which remove carbon dioxide by capturing, absorbing, storing, and fixing carbon dioxide from the atmosphere, are attracting attention. Regarding these negative emission technologies, for example, Patent Document 1 proposes a method for fixing carbon dioxide, characterized by "electrolyzing seawater, separating the anode electrolyzed water and cathode electrolyzed water produced by seawater electrolysis, blowing carbon dioxide gas into the cathode electrolyzed water to fix the carbon dioxide gas as a carbonate, and then combining the anode electrolyzed water after pH adjustment with the cathode electrolyzed water after carbonate fixation and discharging it at a pH equivalent to that of seawater."

[0003] Furthermore, in negative emission technology, technologies for managing the amount of carbon dioxide recovered are also being considered. For example, Patent Document 2 proposes a carbon dioxide recovery management system configured to communicate with a plurality of information terminals, which recovers carbon dioxide from the air using an absorbent material and manages the amount of carbon dioxide recovered, comprising: an information acquisition unit that acquires absorbent material information from each of the plurality of information terminals; a recovery amount determination unit that determines the amount of carbon dioxide recovered based on the absorbent material information; and a storage control unit that stores the amount of carbon dioxide recovered determined by the recovery amount determination unit in a database.

[0004] Japanese Patent Publication No. 5609439, Japanese Unexamined Patent Publication No. 2023-112283

[0005] In the technology described in Patent Document 2, an absorbent material is used to recover carbon dioxide. If information on the saturation level or weight of the absorbent material can be obtained, the amount of carbon dioxide recovered by the absorbent material can be determined based on this information, and the amount of carbon dioxide recovered can be managed. However, in the carbon dioxide fixation system using saltwater such as seawater that the present inventors are considering, carbon dioxide is fixed as carbonate containing components other than carbon dioxide, such as water and metals. Therefore, the amount of carbon dioxide contained per unit weight changes depending on the amount of water and metals contained in the carbonate, and conventional technology cannot easily and accurately calculate the amount of carbon dioxide fixed within the system. Furthermore, in order to measure the amount of carbon dioxide contained in the carbonate with high accuracy, removing the carbonate from the system and processing and analyzing it improves accuracy, but the analysis process becomes more complex and costs increase. In addition, in the system that the present inventors are considering, there are points where gas containing carbon dioxide is introduced and mechanisms for discharging the gas, so it is necessary to consider the inflow and outflow of carbon dioxide from various parts of the system. For this reason, there is a need for a carbon dioxide fixation system and a carbon dioxide fixation method that are configured to easily and accurately calculate and manage the amount of fixation as a whole system. Thus, conventional technology was insufficient to handle carbon credits, which require high precision in the amount of carbon dioxide sequestration, and there was room for improvement.

[0006] Therefore, the object of the present invention is to provide a carbon dioxide fixation system and a carbon dioxide fixation method that can accurately calculate the amount of carbon dioxide fixed.

[0007] To solve the aforementioned problems, the carbon dioxide fixation system according to the present invention includes an electrochemical processing unit that electrochemically decomposes saline water into an acidic aqueous solution and a basic aqueous solution, and a unit that converts CO into the basic aqueous solution. ２ CO2 is mixed with a gas containing CO2 to produce a first aqueous solution. ２ A processing unit, a discharge processing unit that dehydrates the first aqueous solution and generates a carbonate, a first sensor that measures the state value of the carbonate, and based on the state value of the carbonate obtained by the first sensor, CO ２ The system will include a calculation unit for calculating a fixed quantity.

[0008] According to the present invention, a carbon dioxide fixation system and a carbon dioxide fixation method can be provided that can accurately calculate the amount of carbon dioxide fixed.

[0009] This is a diagram showing the configuration of the carbon dioxide fixation system according to the first embodiment. This is a schematic diagram of the electrochemical processing unit of the carbon dioxide fixation system according to the first embodiment. This is a diagram showing the CO2 fixation system according to the first embodiment. ２ Processing unit and CO ２ This is a schematic diagram of the emission processing unit on the processing side. This is a schematic diagram of the neutralization processing unit and the emission processing unit on the neutralization processing side of the carbon dioxide fixation system according to the first embodiment. This is a diagram illustrating the sensor installation configuration. This is a diagram illustrating the sensor installation configuration. This is a diagram illustrating the sensor installation configuration. This is a diagram illustrating the flow of the carbon dioxide fixation method according to the first embodiment. This is a diagram illustrating the flow of the carbon dioxide fixation method according to the first embodiment. This is a diagram illustrating the flow when calculating the prediction model. CO ２ This is a flowchart for calculating fixed quantities using a predictive model. ２ This is a flowchart for calculating fixed quantities. It shows the CO2 for the entire system. ２ This is a diagram showing the flow for calculating the amount of fixed carbon dioxide. This is a schematic diagram of the emission processing unit of the carbon dioxide fixation system according to the second embodiment. This is a schematic diagram showing a modified version of the electrochemical processing unit. This is a schematic diagram showing a modified version of the electrochemical processing unit. This is a schematic diagram showing a modified version of the electrochemical processing unit. This is a schematic diagram showing a modified version of the electrochemical processing unit.

[0010] The carbon dioxide fixation system and carbon dioxide fixation method according to the present invention will be described below with reference to the first and second embodiments. In describing the second embodiment, the explanation of components common to the embodiments already described will be omitted, and the explanation will focus on the differing components.

[0011] [Carbon Dioxide Fixation System According to the First Embodiment] FIG. 1 is an overall configuration diagram of a carbon dioxide fixation system 100 according to the first embodiment. The carbon dioxide fixation system 100 shown in FIG. 1 includes a carbon dioxide fixation device 101 and a computing device 102. The carbon dioxide fixation device 101 includes an electrochemical treatment unit 10, a CO ２ treatment unit 20, a neutralization treatment unit 30, and an exhaust treatment unit 40, and the computing device 102 includes a storage unit 50 and a computing unit 60. Each component of the carbon dioxide fixation system 100 according to the first embodiment is as follows.

[0012] (Electrochemical Treatment Unit) The electrochemical treatment unit 10 electrochemically decomposes brine into an acidic aqueous solution and a basic aqueous solution. Here, the "brine" is not particularly limited as long as it is an aqueous solution containing sodium chloride, and examples include seawater, concentrated seawater, brine (seawater with a high salt concentration that is a by-product of seawater desalination), brine groundwater, and aqueous rock salt solution. In the first embodiment, the case of using seawater will be described. Also, the "acidic aqueous solution" is an aqueous solution containing HCl, and the "basic aqueous solution" is an aqueous solution containing NaOH. The treatment of "electrochemically" decomposing means a treatment of decomposing a compound by applying a voltage between an anode and a cathode to conduct electricity, and examples include electrolysis treatment and electrodialysis treatment. In the first embodiment and the like, the case where the treatment in the electrochemical treatment unit 10 is an electrolysis treatment will be described, but as in the modified examples (FIGS. 11C and 11D) described later, an electrodialysis treatment may also be used.

[0013] The electrochemical processing unit 10, in detail as shown in Figure 2, comprises a decomposition tank 11, an anode 12 connected to the positive electrode, a cathode 13 connected to the negative electrode, and a diaphragm 14 that divides the decomposition tank 11 into an anode side and a cathode side. The diaphragm 14 can be made of any material that allows ions to selectively permeate, such as a cation exchange membrane, an anion exchange membrane, or a bipolar membrane. The materials of the anode 12 and cathode 13 are not particularly limited as long as they can cause the chemical reactions described later. The anode side of the decomposition tank 11 is connected to a pipe t1 for supplying saltwater, a pipe t2 for discharging an acidic aqueous solution, and a pipe t3 for discharging gas generated on the anode side. The cathode side of the decomposition tank 11 is connected to a pipe t4 for supplying water, a pipe t5 for discharging a basic aqueous solution, and a pipe t6 for discharging gas generated on the cathode side. Furthermore, a sensor d1 is provided on pipe t1, a sensor d2 on pipe t2, a sensor d3 on pipe t3, a sensor d4 on pipe t4, a sensor d5 on pipe t5, and a sensor d6 on pipe t6.

[0014] (Electrochemical Processing Unit: Chemical Reactions) The main chemical reactions that occur in the electrochemical processing unit 10 are shown below. <Anode side> 2Cl － →Cl ２ +2e － Cl ２ +H ２ O→HCl+HClO HClO→HCl+1 / 2O ２ <Cathode side> 2H ２ O + 2e － →H ２ +2OH －

[0015] (CO ２ Processing Unit) CO ２ Processing unit 20 adds CO to a basic aqueous solution. ２ This method involves mixing gases containing CO to produce a first aqueous solution. ２ The term "gas containing carbon dioxide" is not particularly limited to any gas containing carbon dioxide, which is the target to be fixed, and includes atmospheric air, exhaust gases, and exhaust gases from animals and biomass. Furthermore, the term "first aqueous solution" refers to an aqueous solution containing carbonate ions, such as NaHCO3.３ Na ２ CO ３ It is an aqueous solution containing the following:

[0016] CO ２ The processing unit 20, in detail as shown in Figure 3, is CO ２ The reactor is equipped with a CO2 reactor. ２ The reaction vessel 21 has a pipe t5 for supplying a basic aqueous solution from the electrochemical processing unit 10, and CO ２ A pipe t7 for supplying a gas containing CO, a pipe t8 for discharging the first aqueous solution, and CO ２ A pipe t9 for discharging the gas generated in the reaction vessel 21 is connected to it. As described above, a sensor d5 is provided in pipe t5, a sensor d7 in pipe t7, a sensor d8 in pipe t8, and a sensor d9 in pipe t9. ２ A sensor d101 is installed inside the reaction tank 21.

[0017] (CO ２ Processing: Chemical reaction) CO ２ The main chemical reactions that occur in the processing unit 20 are shown below: NaOH + CO ２ →NaHCO ３ 2NaOH + CO ２ →Na ２ CO ３ +H ２ O

[0018] (CO ２ Discharge processing unit on the processing side) The discharge processing unit 40 treats the substances after each of the above-mentioned reactions as discharged substances, CO ２ The discharge section 40A on the processing side dehydrates the first aqueous solution to produce carbonate. Here, "carbonate" is a compound containing carbonate ions, but when produced by dehydrating the first aqueous solution, it is mainly Na ２ CO ３ and NaHCO ３ It consists of these components, as well as other substances such as water that was not dehydrated.

[0019] The discharge processing unit 40, in detail as shown in Figure 3, comprises a carbonate dewatering tank 41 and a carbonate recovery tank 42. The carbonate dewatering tank 41 is connected to a pipe t8 for supplying the first aqueous solution and to a pipe t10 for sending the slurry-like carbonate to the carbonate recovery tank 42. As mentioned above, a sensor d8 is provided on pipe t8 and a sensor d10 is provided on pipe t10. Furthermore, a sensor d102 is provided inside the carbonate dewatering tank 41 and a sensor d103 is provided inside the carbonate recovery tank 42.

[0020] (CO ２ Discharge treatment section on the processing side: (chemical reaction) CO ２ The main chemical reactions that occur in the discharge section 40A on the processing side are shown below: NaHCO ３ +Na ２ CO ３ +xH ２ O → NaHCO ３ +Na ２ CO ３ +ΔH ２ O(x>Δ) NaHCO ３ +Na ２ CO ３ +H ２ O → 2NaHCO ３ + NaOH

[0021] (Neutralization Treatment Unit) The neutralization treatment unit 30 mixes a basic substance with an acidic aqueous solution to produce a second aqueous solution. Here, the "basic substance" is not particularly limited as long as it is a substance that can neutralize an acidic aqueous solution, but examples include basic minerals with a large acid neutralization capacity (mol H+ / kg) such as peridotite and basalt. In the first embodiment, the case in which basic minerals containing calcium oxide, magnesium oxide, and calcium carbonate are used will be described. The "second aqueous solution" is an aqueous solution containing chlorides such as calcium and magnesium contained in the basic substance.

[0022] The neutralization unit 30, in detail as shown in Figure 4, includes a neutralization tank 31. The neutralization tank 31 is connected to a pipe t2 for supplying an acidic aqueous solution from the electrochemical unit 10, a pipe t11 for supplying a basic substance, a pipe t12 for discharging a second aqueous solution, a pipe t13 for discharging a slurry containing unreacted solids, and a pipe t14 for discharging gas generated in the neutralization tank 31. As mentioned above, a sensor d2 is provided on pipe t2, a sensor d12 on pipe t12, a sensor d13 on pipe t13, and a sensor d14 on pipe t14. Furthermore, a sensor d104 is provided inside the neutralization tank 31.

[0023] (Neutralization Treatment Section: Chemical Reactions) The main chemical reactions that occur in the neutralization treatment section 30 are shown below. CaO + 2HCl → CaCl ２ +H ２ O MgO+2HCl→MgCl ２ +H ２ O CaCO ３ +2HCl→CaCl ２ +H ２ O+CO ２

[0024] (Discharge section on the neutralization treatment side) The discharge section 40 discharges the substances after each of the above-mentioned reactions, while the discharge section 40B on the neutralization treatment side discharges the second aqueous solution and slurry produced in the neutralization section 30. Here, "slurry" refers to unreacted solids (SiO2) that did not react in the neutralization section 30 among the substances contained in the basic mineral. ２ Al ２ O ３ This includes (etc.).

[0025] The discharge processing unit 40B, in detail as shown in Figure 4, comprises a reaction liquid tank 43 and a slurry receiving tank 44. A pipe t12 for supplying the second aqueous solution from the neutralization processing unit 30 is connected to the reaction liquid tank 43, and a pipe t13 for supplying slurry from the neutralization processing unit 30 is connected to the slurry receiving tank 44. A sensor d105 is provided inside the reaction liquid tank 43, and a sensor d106 is provided inside the slurry receiving tank 44.

[0026] (Sensors) Sensor d measures various state values ​​of aqueous solutions and gases. Sensors d1-d2, d4-d5, d8, d10, d12-d13, and d101-d105, which measure aqueous solutions, measure at least one of the following state values ​​of aqueous solutions and slurries: flow rate, pH, conductivity, component composition, viscosity, and temperature. On the other hand, sensors d3, d6, d7, d9, and d14, which measure gases, measure flow rate, CO2, and other gas state values. ２ Measure the concentration.

[0027] The sensor d is not particularly limited as long as it is a known instrument capable of measuring the various state values ​​described above, but examples include flow meters, pH meters, conductivity meters, component composition analyzers, viscometers, and thermometers. Examples of component composition analyzers include total organic carbon (TOC), Fourier transform infrared spectrophotometers, gas chromatographs, high-performance liquid chromatographs, Raman spectrometers, thermogravimetric-mass spectrometers (TG-MS), X-ray fluorescence analyzers (XRF), and ICP emission spectrometers (ICP). The installation method of the sensor d is not particularly limited, but as shown in Figure 5A, the sensor d may be installed so as to directly measure the object to be measured flowing through the pipe t, or as shown in Figure 5B, a branch channel c may be provided branching off from the pipe t, and the sensor d may be installed in the branch channel c. Furthermore, as shown in Figure 5C, if the sensor d is an optical analyzer, an optical window w that can transmit light may be provided in the pipe t, and the sensor d may be installed so as to analyze the transmitted light. Alternatively, as shown in Figure 5D, a sampler p may be used to extract the sample to be measured flowing through pipe t, and a sensor d may be installed to measure the extracted sample.

[0028] Sensors d10 and d103, which measure the state value of carbonates, are classified as "first sensors," sensor d5, which measures the state value of basic aqueous solutions, is classified as "second sensors," and sensors d8 and d101, which measure the state value of the first aqueous solution, are classified as "third sensors." In addition, sensors d3, d6, and CO2, which measure the state value of gases generated in the electrochemical processing unit 10, are classified as "first sensors." ２Sensor d9, which measures the state value of the gas generated in the processing unit 20, and sensor d14, which measures the state value of the gas generated in the neutralization processing unit 30, are considered "gas sensors".

[0029] (Calculation Unit) As shown in Figure 1, the calculation unit 102 comprises a storage unit 50 and a calculation unit 60. The storage unit 50 stores the state values ​​and prediction models acquired by each sensor d. The calculation unit 60 calculates CO based on the state values ​​and prediction models acquired by each sensor d. ２ Fixed amount, CO ２ Emissions, CO2 from the entire system ２ This device calculates a fixed quantity. The storage unit 50 and the calculation unit 60 of the arithmetic unit 102 are connected by a predetermined wired or wireless connection. The processing of the calculation unit 60 is realized by program execution by the CPU (Central Processing Unit) or by dedicated circuits, etc. The storage unit 50 can be made up of common storage devices such as RAM (Random Access Memory), ROM (Read Only Memory), HDD (Hard Disk Drive), and flash memory. The calculation method by the arithmetic unit 102 will be described in detail later.

[0030] (Other configurations) Pumps and valves capable of adjusting the flow rate of fluids (liquids and gases) may be appropriately installed in each pipe t. Also, the installation location of the sensors d is not limited to the locations shown in the figure, and may be increased or decreased as appropriate. Furthermore, the calculation device 102 may be equipped with a display unit that displays the results calculated by the calculation unit 60.

[0031] [Carbon Dioxide Fixation Method According to the First Embodiment] Next, the carbon dioxide fixation method according to the first embodiment will be described. The carbon dioxide fixation method according to the first embodiment is an electrochemical treatment step S1 and CO2 fixation step S1, as shown in Figure 6A. ２It includes a treatment step S2, a neutralization treatment step S3, and a discharge treatment step S4, and also includes a measurement step S5 and a calculation step S6 shown in FIG. 6B. Note that step S2 and step S3 are carried out in parallel, and steps S5 to S6 are carried out in parallel with the implementation of steps S1 to S4. Hereinafter, each step will be described.

[0032] (Electrochemical treatment step) The electrochemical treatment step S1 is a step of electrochemically decomposing salt water into an acidic aqueous solution and a basic aqueous solution. Referring to FIG. 2, in the electrochemical treatment step S1, a voltage is applied between the anode 12 and the cathode 13 to conduct electricity, and an electrochemical decomposition treatment is performed on the seawater supplied to the decomposition tank 11. By this decomposition treatment, on the anode side, HCl, HClO, etc. are generated, and an acidic aqueous solution containing these is sent out from the pipe t2. On the other hand, on the cathode side, NaOH, etc. are generated, and a basic solution containing this is sent out from the pipe t5. Also, gases such as O ２ , Cl ２ etc. are discharged from the pipe t3, and gases such as H ２ etc. generated by the reaction on the cathode side are discharged from the pipe t6. In addition, CO ２ contained in the seawater is also discharged from the pipes t3 and t6 (especially the pipe t3).

[0033] (CO ２ treatment step) The CO ２ treatment step S2 is a step of mixing a gas containing CO ２ with a basic aqueous solution to generate a first aqueous solution. Referring to FIG. 3, in the CO ２ treatment step S2, a gas containing CO ２ is mixed with the basic solution supplied to the CO ２ reaction tank 21 through the pipe t7. As a result, CO ２ is absorbed by the basic solution, and a first aqueous solution containing NaHCO ３ , Na ２ CO ３ , etc. is sent out from the pipe t8. Also, gases containing CO ２ etc. that were not absorbed by the basic solution are discharged from the pipe t9.

[0034] (Neutralization Treatment Step) The neutralization treatment step S3 is a step of mixing a basic substance with an acidic aqueous solution to produce a second aqueous solution. Referring to FIG. 4, in the neutralization treatment step S3, a basic substance (basic mineral containing calcium oxide, magnesium oxide, and calcium carbonate) is mixed with the acidic aqueous solution supplied to the neutralization tank 31 through the pipe t11. As a result, a neutralization reaction occurs in the neutralization tank 31, and a second aqueous solution containing CaCl ２ , MgCl ２ , etc. is sent out from the pipe t12. Further, a slurry containing unreacted solids (such as SiO ２ , Al ２ O ３ , etc.) that were contained in the basic mineral but did not react in the neutralization tank 31 is sent out from the pipe t13. Also, a gas containing CO ２ , etc. generated by the neutralization reaction in the neutralization tank 31 is discharged from the pipe t14.

[0035] (Discharge Treatment Step) The discharge treatment step S4 is a step of dehydrating the first aqueous solution to produce a carbonate. Referring to FIG. 3, in the discharge treatment step S4, the first aqueous solution supplied to the carbonate dehydration tank 41 is subjected to a dehydration treatment. As a result, a slurry-like carbonate in which NaHCO ３ , Na ２ CO ３ is concentrated is sent out from the pipe t10 and stored in the carbonate recovery tank 42.

[0036] (Measurement Step) The measurement step S5 is a step of measuring the state values of the aqueous solution and the gas by each sensor d. In this measurement step S5, various state values are measured by each sensor d, and then the acquired various state values are stored in the storage unit 50.

[0037] (Calculation Step) The calculation step S6 is a step of calculating the CO ２ fixation amount, the CO ２ emission amount, and the overall system CO ２ fixation amount based on the state values acquired by each sensor and the prediction model, etc.

[0038] (Calculation Step: Calculation of Prediction Model) First, the calculation method of the "prediction model" in the calculation step S6 will be explained. Here, the "prediction model" refers to CO for various state values２ It is associated with a fixed quantity, and by inputting various state values, CO ２ This method allows for the calculation of predicted fixed amounts. Below, we will explain using the case where various state values ​​are the state values ​​of carbonate (flow rate and component composition) as an example. As shown in Figure 7, first, the carbonate generated in the discharge processing unit 40 over a predetermined time is measured, and the CO fixed in the carbonate is calculated. ２ Fixed quantity measurement data (batch data) is acquired (S601). ２ The measurement data for fixed quantities is CO ２ Content measurement (TOC, etc.), weight measurement, H ２ Known measurement methods such as O content measurement (TG-MS, etc.) and metal composition measurement (XRF, ICP, etc.), and CO per unit weight of carbonate ２ It is sufficient to obtain the data using one or more of the quantitative relational formulas. Furthermore, during the predetermined time, the flow rate and component composition (online data) of the carbonate measured by sensors d10 and d103 are obtained from the storage unit 50 (S602). In this way, the "flow rate and component composition of carbonate" and "CO2" during the predetermined time are obtained. ２ We acquire data in combination with "measurement data of a fixed quantity." We then acquire multiple such combinations of data.

[0039] These data (CO ２ After performing preprocessing as necessary on the fixed quantity measurement data, various state values, and combination data (S603), machine learning is performed (S604) to calculate a predictive model (S605). The preprocessing is not particularly limited to general data processing performed in machine learning, and examples include removing missing values, noise values, and error values ​​from the data.

[0040] (Calculation process: CO ２ (Calculation of fixed amount) "CO" in calculation process S6 ２ The method for calculating the "fixed amount" will be explained. As shown in Figure 8A, if the "predictive model" is not used, for example, after obtaining the state values ​​(flow rate and component composition) of the carbonate measured by sensors d10 and d103 (S611), CO is calculated based on these state values. ２The fixed quantity is calculated (S612). In this case, the process of calculating the prediction model (S601-S605) is not mandatory.

[0041] On the other hand, as shown in Figure 8B, when using a "predictive model," for example, after obtaining the state values ​​(flow rate and component composition) of the carbonate measured by sensors d10 and d103 (S621), these state values ​​are applied to the predictive model (S622), CO ２ The fixed amount is calculated (S623). Note that this "CO ２ The various state values ​​used to calculate "fixed quantities" correspond to the various state values ​​used to calculate "predictive models." For example, CO ２ When calculating fixed quantities, if the various state values ​​used are "carbonate flow rate and component composition," "basic aqueous solution flow rate and pH," and "first aqueous solution flow rate and pH," then CO2 will be used when calculating the prediction model. ２ The various state values ​​associated with the fixed quantity measurement data are "carbonate flow rate and component composition," "basic aqueous solution flow rate and pH," and "first aqueous solution flow rate and pH."

[0042] (Calculation process: CO of the entire system) ２ (Calculation of fixed quantities) In calculation process S6, the "CO2 of the entire system" ２ The method for calculating the "fixed amount" will be explained. As shown in Figure 9, the flow rate and component composition are obtained from sensors d3 and d6 as state values ​​of the gas generated in the electrochemical processing unit 10 (S631). Then, based on these state values, the CO generated in the electrochemical processing unit 10 is calculated. ２ The emissions are calculated (S632). Similarly, based on the state value from sensor d9, CO ２ CO generated in processing unit 20 ２ The emission amount is calculated, and based on the state value from sensor d14, the CO2 generated in the neutralization processing unit 30 is determined. ２ Calculate the emissions (S632). These CO ２ The emissions are the CO2 released by the operation of the carbon dioxide sequestration system 100. ２ This is the amount of CO2 that was fixed by the carbon dioxide fixation system 100. ２From the "fixed amount", the "CO2" emitted during the operation of the carbon dioxide fixation system 100. ２ By subtracting "emissions," the "total CO2 emissions of the system" ２ The "fixed amount" can be calculated (S633).

[0043] [Carbon Dioxide Fixation System According to the Second Embodiment] Next, a carbon dioxide fixation system according to the second embodiment will be described. The carbon dioxide fixation system according to the second embodiment differs from the first embodiment in its emission processing unit. Hereinafter, with reference to Figure 10, the emission processing unit 40C of the carbon dioxide fixation system according to the second embodiment will be described in detail.

[0044] (Emission Processing Unit) The emission processing unit 40C of the carbon dioxide fixation system according to the second embodiment is CO ２ A carbonate is produced by mixing a first aqueous solution supplied from the processing unit 20 with a second aqueous solution supplied from the neutralization processing unit 30. Here, "carbonate" refers to a compound containing carbonate ions, but when produced by mixing the first aqueous solution and the second solution, it is mainly CaCO3. ３ , MgCO ３ It is composed of these elements, and also includes water, among other things.

[0045] In detail, as shown in Figure 10, the emission processing unit 40C of the carbon dioxide fixation system according to the second embodiment is CO ２ The system includes a first liquid tank 45 for storing the first aqueous solution supplied from the processing unit 20, a second liquid tank 46 for storing the second aqueous solution supplied from the neutralization processing unit 30, a carbonate generation tank 47 to which the first aqueous solution and the second aqueous solution are supplied, and a carbonate recovery tank 48 for recovering the generated carbonate. The first liquid tank 45 contains CO ２A pipe t8 is connected to the processing unit 20 to supply the first aqueous solution, and a pipe t15 is connected to discharge the first aqueous solution. A pipe t12 is connected to the second liquid tank 46 to supply the second aqueous solution from the neutralization processing unit 30, and a pipe t16 is connected to discharge the second aqueous solution. A pipe t17 is connected to the carbonate generation tank 47 to discharge the gas generated in the tank, and a pipe t18 is connected to discharge the slurry-like carbonate to the carbonate recovery tank 48. Sensors d15, d16, d17, and d18 are provided on pipes t15, t16, t17, and t18. Furthermore, a sensor d106 is provided inside the first liquid tank 45, a sensor d107 inside the second liquid tank 46, a sensor d108 inside the carbonate generation tank 47, and a sensor d109 inside the carbonate recovery tank 48. The configuration of each sensor d is as described in the first embodiment.

[0046] (Discharge Processing Unit: Chemical Reactions) The main chemical reactions that occur in the discharge processing unit 40C are shown below. CaCl ２ +Na ２ CO ３ →CCO ３ +2NaCl MgCl ２ +Na ２ CO ３ →MgCO ３ +2NaCl CaCl ２ +2NaHCO ３ →CO ２ +CaCO ３ +H ２ O+2NaCl MgCl ２ +2NaHCO ３ →CO ２ +MgCO ３ +H ２ O + 2NaCl

[0047] (Other Configurations) The other configurations of the carbon dioxide fixation system according to the second embodiment are the same as those of the first embodiment, so their description is omitted.

[0048] [Carbon Dioxide Fixation Method According to the Second Embodiment] The carbon dioxide fixation method according to the second embodiment differs from the first embodiment in its emission treatment process and calculation process. The following description will focus on the emission treatment process and calculation process of the carbon dioxide fixation method according to the second embodiment.

[0049] (Emission Treatment Process) The emission treatment process of the carbon dioxide fixation method according to the second embodiment is a process of mixing the first aqueous solution and the second aqueous solution to produce a carbonate. Referring to Figure 10, in the emission treatment process, CO ２ The first aqueous solution is supplied from the processing unit 20 to the carbonate generation tank 47 via the first liquid tank 45, and the second aqueous solution is supplied from the neutralization processing unit 30 to the carbonate generation tank 47 via the second liquid tank 46. Then, the first aqueous solution and the second aqueous solution are mixed in the carbonate generation tank 47. As a result, CaCO3 is produced in the carbonate generation tank 47. ３ or MgCO ３ These are generated, and a slurry-like carbonate containing these is sent out from pipe t18 and stored in carbonate recovery tank 48. In addition, CO2 generated by chemical reactions in carbonate generation tank 47 is produced. ２ Gases such as these are discharged from pipe t17.

[0050] (Calculation process) The emission processing unit 40C of the carbon dioxide fixation system according to the second embodiment differs from that of the first embodiment in that CO ２ It may generate gases containing CO2 in the calculation process. ２ When calculating the "fixed amount," the electrochemical processing unit 10 and CO2 are used based not only on the state values ​​from sensors d3 and d6, sensor d9 and sensor d14, but also on the state value from sensor d17. ２ CO generated in the processing unit 20, the neutralization processing unit 30, and the discharge processing unit 40C ２ The emissions are calculated. The subsequent processing is the same as in the first embodiment, where the carbon dioxide that has been fixed by the carbon dioxide fixation system is processed. ２ From "fixed amount" to "CO ２ By subtracting "emissions", the "total CO2 emissions of the system" ２ You just need to calculate the "fixed amount".

[0051] (Other steps) The other steps of the carbon dioxide fixation method according to the second embodiment are the same as those of the first embodiment, so their description is omitted.

[0052] (Effect) According to the carbon dioxide fixation system and carbon dioxide fixation method according to the first and second embodiments, based on the carbonate state values ​​acquired by sensors d10 and d103, CO ２ Fixed quantities can be calculated with high accuracy. Furthermore, by using not only various state values ​​but also predictive models, the CO2 contained in the generated carbonate can be calculated. ２ This eliminates the need to measure the amount of CO2 one by one, and also reduces the need for continuous CO2 ２ This enables monitoring of fixed quantities.

[0053] When the carbon dioxide sequestration system is in operation, each part will release CO ２ CO2 may be emitted. Specifically, in the electrochemical processing unit 10, CO2 contained in the saltwater may be released. ２ CO2 is emitted. ２ In the processing unit 20, the excess CO that was not dissolved in the basic aqueous solution ２ In addition, the neutralization treatment unit 30 determines the type of basic substance (CaCO3). ３ (Minerals containing CO) ２ CO is discharged, and in the discharge processing unit 40, the first aqueous solution and the second aqueous solution are mixed to produce a carbonate. ２ CO2 is emitted. In other words, carbon dioxide sequestration systems emit CO2. ２ Despite being a system intended to recover CO2, ２ There is a possibility of emitting CO2. According to the carbon dioxide fixation system and carbon dioxide fixation method according to the first and second embodiments, CO2 may be released in each part. ２ Since the configuration is for calculating emissions, the CO ２ CO2 emissions taken into account for the entire system ２ It can calculate a "fixed amount".

[0054] [Modified Version] (Modified Version: Electrochemical Processing Unit) The electrochemical processing unit 10 is not limited to the configuration shown in Figure 2. For example, the electrochemical processing unit 10A shown in Figure 11A differs from the electrochemical processing unit 10 in Figure 2 in that pipes t20 and t21 are connected to the anode and cathode sides of the decomposition tank 11A so that gas can be supplied from below. The gas supplied from pipes t20 and t21 is a gas that reduces the electrolysis voltage in the electrochemical processing unit 10A (for example, CO on the anode side and O on the cathode side). ２ CO ２ (e.g.)

[0055] The electrochemical processing unit 10B shown in Figure 11B is configured to use a gas diffusion electrode as the cathode 13B. In the electrochemical processing unit 10B, brine is supplied to the anode side from pipe t22, and water is supplied to the cathode side from pipe t23. An acidic aqueous solution is discharged from pipe t24, and a basic aqueous solution is discharged from pipe t25. In addition, the O2O2 generated by the reaction is discharged from pipe t26. ２ or Cl ２ Gas containing the above is discharged. Furthermore, gas is supplied from pipe t27 and discharged from pipe t28.

[0056] The electrochemical processing unit 10C shown in Figure 11C has a configuration using a bipolar membrane as the diaphragm 14C. Saltwater is supplied to the electrochemical processing unit 10C from pipe t29 and water from pipe t30. Acidic aqueous solution is discharged from pipe t31 and basic aqueous solution is discharged from pipe t32.

[0057] The electrochemical processing unit 10D shown in Figure 11D has a configuration using two membranes: an anion exchange membrane 14D and a cation exchange membrane 14E. The electrochemical processing unit 10D is supplied with brine from pipe t33, and with water from pipes t34 and t35. An acidic aqueous solution is discharged from pipe t36, a basic aqueous solution from pipe t37, and desalinated water from pipe t38.

[0058] Furthermore, the electrochemical processing units 10A to D shown in Figures 11A to D are configured such that sensors d are placed in the piping through which aqueous solutions and gases are supplied, and in the piping through which they are delivered, thereby enabling appropriate monitoring of various state values ​​in the electrochemical processing unit 10.

[0059] (Modified Version: Electrochemical Processing Unit) In the first embodiment and the modified version described above, a method of supplying water to the cathode side of the electrochemical processing unit 10 was explained, but it is not limited to water as long as the desired chemical reaction occurs. For example, the water may contain a base (NaOH), etc.

[0060] (Variation example: CO2 of the entire system in the calculation process) ２ (Calculation of fixed quantities) In calculation process S6, the "CO2 of the entire system" ２ When calculating the fixed amount, the electrochemical processing unit 10, CO ２ For all of the processing unit 20, neutralization processing unit 30, and discharge processing unit 40, "CO ２ There is no need to calculate the "emissions". For example, in the neutralization processing unit 30, CO ２ If CO does not occur, ２ If the amount of CO generated is extremely small, the neutralization processing unit 30 ２ The configuration may not involve calculating emissions. In other words, the electrochemical processing unit 10, CO ２ In at least one of the processing unit 20, neutralization processing unit 30, and discharge processing unit 40, the state value of the generated gas is measured by a sensor, and CO is calculated from the state value of the gas. ２ All you need to do is calculate the emissions.

[0061] (Modified Version: Calculation Unit) The calculation unit 102 may simply monitor whether the electrochemical processing is being carried out appropriately based on various state values ​​acquired by the sensor d in the electrochemical processing unit 10, but it may also be provided with a signal transmitting unit that sends a warning signal to the outside when the various state values ​​deviate from a predetermined range. Furthermore, the calculation unit 102 may also be provided with a control unit that controls the flow rate and voltage of each aqueous solution supplied based on various state values ​​acquired by the sensor d in the electrochemical processing unit 10, as well as the values ​​of the ammeter and voltmeter. For details regarding these signal transmitting units and control units, see CO ２The same applies to the processing unit 20, the neutralization processing unit 30, and the discharge processing unit 40.

[0062] (Modified example: Neutralization process) In the neutralization process S3, the type of basic substance to be supplied from the piping t11 may be selected based on various state values ​​(especially pH, and the component composition of the aqueous solution or gas) acquired by the sensors d2, d12, d13, d14, and d104 shown in Figure 4.

[0063] It should be noted that the present invention is not limited to the embodiments and modifications described above. Furthermore, the embodiments and modifications are described in detail for the purpose of clearly illustrating the present invention, and are not necessarily limited to those having all the configurations described. In addition, it is possible to replace a part of the configuration of one embodiment with the configuration of another embodiment or modification, or to add the configuration of another embodiment or modification.

[0064] 10 Electrochemical processing unit 11 Decomposition chamber 12 Anode 13 Cathode 14 Diaphragm 20 CO ２ Processing Unit 21 CO ２ Reaction tank 30 Neutralization processing unit 31 Neutralization tank 40 Discharge processing unit 41 Carbonate dehydration tank 42 Carbonate recovery tank 43 Reaction liquid tank 44 Slurry receiving tank 45 First liquid tank 46 Second liquid tank 50 Memory unit 60 Calculation unit 100 Carbon dioxide fixation system 101 Carbon dioxide fixation device 102 Calculation device d Sensor t Piping c Branch channel w Optical window p Sampler S1 Electrochemical processing step S2 CO ２ Treatment process S3 Neutralization process S4 Discharge treatment process S5 Measurement process S6 Calculation process S601 to S633 Each calculation process

Claims

An electrochemical processing unit that electrochemically decomposes salt water into acidic and basic aqueous solutions, CO ２ CO2 is mixed with a gas containing CO2 to produce a first aqueous solution. ２ Processing unit and A discharge processing unit that dehydrates the first aqueous solution and generates a carbonate, A first sensor for measuring the state value of the carbonate, Based on the carbonate state value acquired by the first sensor, ２ A carbon dioxide fixation system characterized by comprising a calculation unit for calculating the amount of fixation. 　 The carbon dioxide fixation system includes a neutralization section that mixes a basic substance with the acidic aqueous solution to produce a second aqueous solution, The carbon dioxide fixation system according to claim 1, characterized in that the discharge processing unit mixes the first aqueous solution and the second aqueous solution to produce a carbonate. 　 CO2 ２ It comprises a memory unit that stores a predictive model associated with a fixed quantity, The calculation unit, based on the carbonate state value acquired by the first sensor and the prediction model, calculates CO ２ The carbon dioxide fixation system according to claim 2, characterized in that it calculates the amount of fixation. 　 At least one of a second sensor for measuring the state value of the basic aqueous solution and a third sensor for measuring the state value of the first aqueous solution, CO ２ It comprises a memory unit that stores a predictive model associated with a fixed quantity, The calculation unit, based on at least one of the state values ​​of the basic aqueous solution acquired by the second sensor and the state value of the first aqueous solution acquired by the third sensor, the state value of the carbonate acquired by the first sensor, and the prediction model, calculates CO ２ The carbon dioxide fixation system according to claim 2, characterized in that it calculates the amount of fixation. 　 The aforementioned prediction model obtains CO2 by measuring the carbonate generated in the emission processing unit. ２ The carbon dioxide fixation system according to claim 3 or 4, characterized in that it is a model calculated by machine learning using multiple data sets of combinations of fixed quantity measurement data and the state value at the time the measurement data was obtained. 　 The carbon dioxide fixation system according to any one of claims 1 to 4, characterized in that the state value is at least one of flow rate, pH, conductivity, component composition, viscosity, and temperature. 　 The electrochemical treatment unit, the CO ２ At least one of the treatment unit, the neutralization treatment unit, and the discharge treatment unit includes a gas sensor that measures the state value of the generated gas. The calculation unit calculates CO from the gas state value obtained by the gas sensor. ２ In addition to calculating the emissions, the calculated CO2 ２ Emissions and CO2 ２ Based on fixed quantities, the CO2 of the entire system ２ A carbon dioxide fixation system according to any one of claims 2 to 4, characterized by calculating the amount of fixation. 　 An electrochemical treatment process in which saline solution is electrochemically decomposed into an acidic aqueous solution and a basic aqueous solution, CO ２ CO2 is mixed with a gas containing CO2 to produce a first aqueous solution. ２ Processing steps, A discharge treatment step of dehydrating the first aqueous solution to produce a carbonate, A measurement step of measuring the state value of the carbonate using a first sensor, Based on the carbonate state value acquired by the first sensor, ２ A method for fixing carbon dioxide, characterized by comprising a calculation step for calculating the amount of fixation. 　 The carbon dioxide fixation method includes a neutralization step of mixing a basic substance with the acidic aqueous solution to produce a second aqueous solution, The carbon dioxide fixation method according to claim 8, characterized in that the first aqueous solution and the second aqueous solution are mixed in the discharge treatment step to produce a carbonate. 　 In the calculation step, CO is used to determine the state value of the carbonate. ２ Based on the predictive model associated with a fixed quantity and the carbonate state value acquired by the first sensor, CO ２ The carbon dioxide fixation method according to claim 9, characterized by calculating the amount of fixation. 　 In the measurement step, at least one of the following is performed: measuring the state value of the basic aqueous solution with a second sensor, and measuring the state value of the first aqueous solution with a third sensor. In the calculation step, CO is applied to at least one of the state values ​​of the carbonate, the state value of the basic aqueous solution, and the state value of the first aqueous solution. ２ Based on a predictive model associated with a fixed amount, at least one of the state values ​​of the basic aqueous solution acquired by the second sensor and the state value of the first aqueous solution acquired by the third sensor, and the state value of the carbonate acquired by the first sensor, CO ２ The carbon dioxide fixation method according to claim 9, characterized by calculating the amount of fixation. 　 In the measurement step, the electrochemical treatment step, the CO ２ In at least one of the processing step, the neutralization processing step, and the discharge processing step, the state value of the generated gas is measured by a gas sensor. In the calculation step, CO is calculated from the gas state value acquired by the gas sensor. ２ In addition to calculating the emissions, the calculated CO2 ２ Emissions and CO2 ２ Based on fixed quantities, the CO2 of the entire system ２ A method for fixing carbon dioxide according to any one of claims 9 to 11, characterized by calculating the amount of fixation.

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