Co2 separation recovery conversion device and co2 separation recovery conversion method

Abstract

To provide a CO2 separation recovery conversion device which achieves low operation costs, has a smaller scale facility compared to conventional devices, and converts CO2 into resources.SOLUTION: A CO2 separation recovery conversion device 1 according to the invention includes: a closed type first tank 11 which can store an amine solution including a tertiary amine; an exhaust port 12 provided in the first tank 11; amine solution supply means 13 which supplies the amine solution to the first tank 11; chloride salt supply means 14 which supplies a chloride salt solution or chloride salt powder to the first tank 11; a diffusion plate 15 which diffuses a CO2 containing gas into the amine solution; stirring blades 16 provided above the diffusion plate 15; a concentration part 17 having a cone shape in which a horizontal cross section area becomes smaller toward the lower end of the first tank 11; a rake 18 which rotates in the concentration part 17; and a first discharge port 19 which is provided at the lower part of the rake 18 to discharge carbonate accumulated in the concentration part 17 to the outside.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a carbon dioxide (CO2) separation and capture device and a CO2 separation and capture method. [Background technology]

[0002] Regarding the reduction of CO2 emissions, while progress is being made in the development of electrical appliances that do not emit CO2, there are still products and equipment that cannot avoid emitting CO2. For example, gas engines for power generation and thermal power plants that use methane gas as fuel generate large amounts of CO2. In recent years, several methods for separating and capturing CO2 have been developed. Examples of such CO2 separation and capture methods include physical adsorption methods such as the pressure swing adsorption (PSA) method and the thermal swing adsorption (TSA) method, membrane separation methods, and chemical absorption methods using amine solutions. Among these, the chemical absorption method has an overwhelming advantage over the other two methods in terms of the high CO2 capture rate and the purity of the captured CO2 (e.g., Non-Patent Documents 1 to 3).

[0003] Non-Patent Document 1 describes the Direct Air Capture (DAC) method, its operating costs, etc. Non-Patent Document 1 also describes that it is advantageous to combine the DAC method with the amine absorption method, which is a chemical absorption method. Here, Fig. 27 is a schematic diagram for explaining the structure of a device for a conventional amine absorption method. As shown in Fig. 27, the structure of the device for the conventional amine absorption method includes an amine absorption tower 260 and a regeneration tower 270 that heats an amine solution containing CO2 at 110 to 130°C to recover CO2 from the amine solution and regenerate the amine solution. Fig. 28 is a schematic diagram for explaining the structure of a conventional amine absorption tower 260. As shown in Fig. 28, the amine absorption tower 260 has a cylindrical or square tube-shaped main body 261, a liquid distributor 262 provided on the upper part of the main body 261, a packed bed 263 having a packing material (agent) provided on the lower part of the liquid distributor 262, a support plate 264 supporting the packed bed 263 and having a hole portion for passing the amine solution and the CO2-containing gas, an inlet 265 provided below the support plate 264 and on the side wall of the main body 261 for introducing a gas containing CO2, an outlet 266 provided below the inlet 265 for discharging the amine solution, and an exhaust port 267 provided on the lid of the upper part of the main body for discharging the gas. The amine solution sprayed from the liquid distributor 262 through the piping comes into contact with the CO2-containing gas introduced from the inlet 265 below the support plate 264 as it passes through the packed bed 263, absorbs the CO2, and is discharged from the outlet 266 at the bottom of the main body. The amine solution containing CO2 in the form of carbamate or bicarbonate ion discharged from the outlet 266 is sent to the regeneration tower 270. Meanwhile, the gas from which CO2 has been removed by absorbing CO2 rises inside the tower and is exhausted from the exhaust port 267. In the regeneration tower 270, the amine solution that has absorbed CO2 is heated to 110 to 130°C, and the amine solution and CO2 are separated. The amine solution that has been separated from CO2 and regenerated is supplied to the amine absorption tower 260 again. The amine solution and the CO2 separated from the amine solution are converted into resources in a separate process.

[0004] On the other hand, Non-Patent Document 2 describes a carbon dioxide separation technology from blast furnace gas using the PSA method. However, the PSA method described in Non-Patent Document 2 has a drawback in that, as shown in FIG. 29, increasing the purity of the captured CO2 reduces the CO2 recovery rate. FIG. 29 is a graph explaining the separation of carbon dioxide using a CO2 adsorbent 281 using zeolite and activated carbon 282. In the figure, the horizontal axis indicates CO2 Recovery (purity of the captured CO2) (%), and the vertical axis indicates CO2 Purity (CO2 recovery rate) (%). The PSA method is inferior to the chemical absorption method using amines, etc., in terms of CO2 removal rate (recovery rate) and purity of the captured CO2, and cannot reduce the CO2 concentration in the treated gas to 50 ppm or less, as in the chemical absorption method.

[0005] In addition, Non-Patent Document 3 describes a membrane separation method such as a CO2 separation membrane using zeolite. Furthermore, Non-Patent Document 3 describes an example of separation of methane and CO2. Here, for example, when separating and recovering CO2 in natural gas and liquefying methane gas, it is necessary to reduce the CO2 concentration, which is the domestic LNG standard, to 100 ppm or less. However, a general membrane separation method does not have the CO2 removal performance as the chemical absorption method, and cannot reduce the CO2 concentration in the treated gas to 100 ppm or less like the amine absorption method (chemical absorption method). Therefore, in the membrane separation method, in order to separate and recover the CO2 remaining in the treated gas after membrane separation, treatment is performed by AGR (Acid Gas Removal), a chemical absorption method using amines or the like. This is also true for the CO2 separation membrane described in Non-Patent Document 3. Note that FIG. 30 is an explanatory diagram explaining the separation of methane and CO2 by the membrane separation method. This FIG. 30 illustrates a membrane separation method with a general separation factor of 30. FIG. 31 is an explanatory diagram illustrating a case where CO2 is separated by a membrane separation method, then treated by AGR to reduce the CO2 concentration to less than 50 ppm, which satisfies the Japanese LNG standard. In the example of Figure 30, the membrane allows 90% of the CO2 supply and 23.1% of the CH4 supply to permeate, while leaving 10% of the CO2 supply and 76.9% of the CH4 supply on the non-permeated side. Therefore, as shown in Figure 31, for example, sour gas (natural gas) containing 40 mol% CO2 is treated with a membrane, and the CO2 remaining on the non-permeated side of the membrane is treated and captured by AGR, and the CO2 concentration in the treated natural gas is reduced to less than 50 ppm, which meets Japan's LNG standards. [Prior art documents] [Non-patent literature]

[0006] [Non-Patent Document 1] "Cost and Evaluation of Direct Air Capture (DAC) Method for Carbon Dioxide," Low Carbon Society Strategy Center, Japan Science and Technology Agency, February 2020 [Non-Patent Document 2] Hitoshi Saima, Yasuhiro Mogi, Takashi Haraoka, "Development of Carbon Dioxide Separation Technology from Blast Furnace Gas by PSA Method", JFE Techniques, August 2013, No. 32, pp. 44-49 [Non-Patent Document 3] Yutaka Morita, Takeo Kawase, Kazuaki Miyata, "Development of efficient CO2 separation and capture technology using zeolite membranes", Journal of the Japanese Petroleum Technology Association, November 2016, Vol. 81, No. 6, pp. 452-457 (DOI:10.3720 / japt.81.452) Summary of the Invention [Problem to be solved by the invention]

[0007] Regarding the conventional amine absorption method apparatus having the above-mentioned device structure, reference 1 (Hiroshi Komiyama, Yoshi Fujitani, "Comparative Study of CO2 Separation Process from the Viewpoint of Energy Efficiency", Chemical Engineering Journal, 1993, Vol. 19, No. 5, pp. 818-828) states that "When CO2-containing gas passes through a packing material coated with an absorbing solution (amine solution), CO2 is absorbed by the absorbing solution on the packing material surface. The energy consumption is 4 GJ / t-CO2 or more, which is largely due to the heating energy required to regenerate the amine solution, and it is required to reduce this to 2 GJ / t-CO2 or less in the future." In addition, according to reference 2 ("Carbon Recycling Technology Roadmap", Ministry of Economy, Trade and Industry, Revised July 2021, p. 7), it is described that the operating cost (CO2 gas recovery cost) is high, about 4,000 yen / t-CO2, when implementing the conventional amine absorption method. In other words, the conventional amine absorption method had the problem of high operating costs due to high energy consumption.

[0008] In addition, the aforementioned Non-Patent Document 1 calculates the CO2 concentration at the outlet of the absorber and the required height of the packed bed when CO2 in coal-fired power plant flue gas (power generation capacity: 958 MW, flue gas CO2 concentration: 13.7%) is captured by the amine absorption method using a model amine solution (AMP: 2-amino-2-methyl-1-propamol, 40°C, 1M solution). In this calculation, the CO2 mass transfer coefficient Ky·a is 38 kmol / m 2 ·hr. The results are shown in Figure 32. Here, Figure 32 is a graph explaining the relationship between the CO2 concentration at the outlet of the absorber and the height of the packed bed. In this figure, the horizontal axis represents the CO2 concentration (CO2 mole fraction) at the outlet of the absorber, and the vertical axis represents the height of the packed bed (m).

[0009] As shown in Figure 32, when capturing CO2 in coal-fired power plant flue gas using the amine absorption method, the higher the packed bed must be, the lower the CO2 concentration is to be. Referring to Figure 32, it can be seen that to reduce the CO2 concentration in the flue gas to less than 50 ppm (0.005%), which meets Japan's LNG standard, the height of the packed bed must be close to 50 m. In other words, when attempting to increase the recovery rate of CO2 separation and capture and the purity of the captured CO2, the conventional amine absorption method has the problems of high operating costs for regenerating the amine solution as described above, as well as the height of the amine absorption tower including the packed bed reaching several tens of meters, making the scale of the equipment large.

[0010] Furthermore, none of Non-Patent Documents 1 to 3 provides a sufficient explanation about the specific resource conversion of the CO2 separated and captured by the amine absorption method.

[0011] The present invention has been made in view of the above circumstances. An object of the present invention is to provide a CO2 separation, capture and conversion apparatus and a CO2 separation, capture and conversion method that can convert CO2 into resources while reducing operating costs and requiring smaller equipment than conventional methods. [Means for solving the problem]

[0012] The CO2 separation, capture and conversion apparatus according to the present invention, which has solved the above-mentioned problems, comprises: a sealed first tank capable of storing an amine solution containing a tertiary amine; an exhaust port provided in a gas phase portion of the first tank; an amine solution supplying means for supplying the amine solution into the first tank; a chloride salt supplying means for supplying a chloride salt solution or a chloride salt powder into the first tank; an aeration plate provided in a lower portion of the first tank for diffusing bubbles containing CO2 gas into the amine solution; a stirring blade provided above the aeration plate for supplying the chloride salt solution or the chloride salt powder to the amine solution in which the bubbles containing CO2 gas have been sufficiently diffused and then stirring the mixed solution; a cone-shaped concentrating section provided below the aeration plate and having a horizontal cross-sectional area gradually decreasing toward the lower end of the first tank; a rake that rotates within the concentrating section along the slope of the concentrating section; and a first discharge port provided below the rake for discharging to the outside carbonate that has been converted by the supply of the chloride salt solution or the chloride salt powder and accumulated in the concentrating section. Effect of the Invention

[0013] According to the present invention, it is possible to provide a CO2 separation, capture and conversion apparatus and a CO2 separation, capture and conversion method which have low operating costs, require smaller equipment scale than conventional equipment, and can convert CO2 into resources. Problems, configurations and effects other than those described above will become apparent from the following description of the embodiments. [Brief description of the drawings]

[0014] [Figure 1] FIG. 1 is a schematic diagram illustrating the configuration of a CO2 separation, capture and conversion apparatus 1 according to a first embodiment. [Diagram 2] FIG. 2 is an explanatory diagram showing the form of carbon dioxide present in water. [Diagram 3] FIG. 1 is an explanatory diagram showing the relationship between CO2 loading and pH. [Figure 4] FIG. 1 is a schematic diagram illustrating the configuration of a CO2 separation, capture and conversion device 2 according to a second embodiment. [Diagram 5]FIG. 11 is a schematic diagram illustrating the configuration of a CO2 separation, capture and conversion device 3 according to a third embodiment. [Figure 6] FIG. 11 is a schematic diagram illustrating the configuration of a CO2 separation, capture and conversion device 4 according to a fourth embodiment. [Figure 7] 1 is a graph illustrating the change over time in aeration time and CO2 absorption amount. [Figure 8] 1 is a graph relating to the calculation of the mass capacity factor kLa. [Figure 9] 1 is a graph showing the relationship between the concentration of an absorbing liquid (amine solution) and viscosity. [Figure 10] FIG. 11 is a schematic diagram illustrating another configuration of the CO2 separation, capture and conversion device 4 according to the fourth embodiment. [Figure 11] FIG. 11 is a schematic diagram illustrating a CO2 separation, capture and conversion apparatus 5 according to a fifth embodiment. [Figure 12] FIG. 13 is an explanatory diagram illustrating a configuration example of a CO2 separation, capture and conversion device 5 according to a fifth embodiment. [Figure 13] FIG. 13 is an explanatory diagram for explaining an example of a specific operation method of the CO2 separation, capture and conversion apparatus 5 according to the fifth embodiment. [Figure 14] FIG. 11 is a schematic diagram illustrating a CO2 separation, capture and conversion apparatus 6 according to a sixth embodiment. [Figure 15] FIG. 13 is a schematic plan view illustrating a CO2 separation, capture and conversion apparatus 7 according to a seventh embodiment. [Figure 16] FIG. 13 is a schematic diagram illustrating a CO2 separation, capture and conversion device 8 according to an eighth embodiment. [Figure 17] FIG. 13 is a flow chart for explaining the contents of the CO2 separation, capture and conversion method according to the tenth embodiment. [Figure 18] FIG. 1 is an explanatory diagram (photograph) illustrating a state in which a chemical absorption experiment using a tertiary amine was conducted. [Figure 19] This is a photograph showing the state in which a calcium chloride solution is added to an absorption liquid that has absorbed CO2. [Figure 20] 1 is a graph showing the change over time in removal rate for each concentration of the absorbing solution. [Figure 21]1 is a graph showing the relationship between CO2 loading, conversion rate to calcium carbonate, and pH. [Figure 22] 1 is a graph showing the particle size distribution of the obtained calcium carbonate particles. [Diagram 23] 1 is a graph showing the relationship between CO2 loading and CO2 removal rate. [Figure 24] 1 is a graph showing the relationship between aeration time and CO2 absorption amount. [Diagram 25] 1 is a graph showing the relationship between the concentration of an absorbing solution and the absorption limit amount of CO2. [Figure 26] 1 is a graph showing the relationship between the concentration of an absorbing solution and the CO2 absorption rate, conversion rate, and CO2 loading when calcium chloride powder is used. [Figure 27] FIG. 1 is a schematic diagram illustrating an apparatus structure for a conventional amine absorption method. [Figure 28] FIG. 2 is a schematic diagram illustrating the structure of a conventional amine absorption tower 260. [Figure 29] 1 is a graph illustrating separation of carbon dioxide gas by a CO2 adsorbent 281 using zeolite and activated carbon 282. [Diagram 30] FIG. 1 is an explanatory diagram illustrating the separation of methane and CO2 by membrane separation. [Diagram 31] This is an explanatory diagram explaining the case where CO2 is separated by membrane separation and then treated by AGR to reduce the CO2 concentration to less than 50 ppm, which meets Japan's LNG standards. [Diagram 32] 1 is a graph illustrating the relationship between the CO2 concentration at the outlet of the absorber and the height of the packed bed. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Hereinafter, a CO2 separation, capture and conversion apparatus and a CO2 separation, capture and conversion method according to one embodiment of the present invention will be described in detail with reference to the drawings as appropriate. In the description of each embodiment, the same components are denoted by the same names and symbols, and duplicate descriptions may be omitted.

[0016] [CO2 separation and capture equipment] (First embodiment) FIG. 1 is a schematic diagram illustrating the configuration of a CO2 separation, capture and conversion apparatus 1 according to the first embodiment. As shown in FIG. 1, the CO2 separation, capture and conversion apparatus 1 according to the first embodiment includes a first tank 11, an exhaust port 12, an amine solution supply means 13, a chloride salt supply means 14, an air diffuser 15, an agitator blade 16, a concentrating section 17, a rake 18, and a first exhaust port 19.

[0017] The first tank 11 is a sealed tank capable of storing an amine solution containing a tertiary amine. Any tank made of metal such as SUS that is not corroded by the amine solution, the chloride salt solution or the chloride salt powder described below can be used as the first tank 11. The first tank 11 can be preferably cylindrical or rectangular, but is not limited thereto. The exhaust port 12 is provided in the gas phase part of the first tank 11. The exhaust port 12 may be provided with an arbitrary switching valve, a check valve, or the like.

[0018] The amine solution supplying means 13 supplies the amine solution into the first tank 11. As described above, the amine solution contains a tertiary amine. A tertiary amine is a compound in which three hydrogen atoms of ammonia (NH3) are substituted with a hydrocarbon group or an aryl group, and has a structure shown in general formula 1. In general formula 1, R 1 ~R 3 are each a hydrocarbon group or an aryl group.

[0019] [ka]

[0020] As the tertiary amine, for example, methyldiethanolamine (N-Methyldiethanolamine; MDEA; CH3N(C2H4OH)2), triethanolamine (TEA), ethyldiethanolamine (EDEA), etc. can be used. Among these, MDEA can be preferably used in this embodiment, and MDEA is used in the experimental example described later.

[0021] As the tertiary amine, for example, the hydrazone series shown in Table 1 (molecular formula: C 31 H 25 N3), phenylenediamine (molecular formula: C 30 H 24 N2), benzidine (molecular formula: C 36 H 28 N2), styryl (molecular formula: C 32 H 25 N), bisstyryl (molecular formula: C 46 H 36 N2), (Molecular formula: C 38 H 32 N2), (C 40 H 36 Aromatic tertiary amines such as N2) can also be used.

[0022] [Table 1]

[0023] As the aromatic tertiary amine, for example, the compounds shown in Tables 2 and 3 can also be suitably used.

[0024] [Table 2]

[0025] [Table 3]

[0026] As a solvent for the amine solution containing a tertiary amine, for example, water can be used. The concentration of the tertiary amine in the amine solution is, for example, preferably 10 to 40 mass%, more preferably 20 to 40 mass%, and even more preferably 30 to 40 mass%. By setting the concentration of the tertiary amine in the amine solution in this way, it is possible to efficiently separate and recover almost all (95 to 100%) of the CO2. If the concentration of the tertiary amine in the amine solution exceeds 40 mass%, it is necessary to make the equipment explosion-proof, which is not preferable because it increases the construction cost. Also, if the concentration of the tertiary amine in the amine solution exceeds 40 mass%, the viscosity of the amine solution increases, so that the bubbles generated at the air diffuser plate 15 merge and become larger, and the rising speed of the bubbles increases. Therefore, the residence time of the bubbles becomes shorter and the specific surface area becomes smaller. Also, as the viscosity of the amine solution increases, the transfer coefficient becomes smaller. Due to these factors, it may become impossible to efficiently separate and recover the CO2.

[0027] The amine solution supply means 13 may include, for example, a first storage tank (not shown) for storing the amine solution, a second pipe (not shown) connecting the first storage tank and the first tank 11, and a pump (not shown) provided on the second pipe. In this way, an arbitrary volume of amine solution can be supplied from the first storage tank to the first tank 11 by operating the pump.

[0028] The chloride salt supplying means 14 supplies a chloride salt solution or a chloride salt powder into the first tank 11. For example, calcium chloride, sodium chloride, magnesium chloride, etc. can be used as the chloride salt contained in the chloride salt solution. For the chloride salt powder, powdered versions of these salts can be used. In the experimental examples described below, a calcium chloride solution and powdered calcium chloride are used as the chloride salt. For example, water can be used as the solvent for the chloride salt solution.

[0029] The chloride salt supplying means 14 may, for example, include a second storage tank (not shown in FIG. 1) for storing a chloride salt solution or a chloride salt powder, a third pipe (not shown in FIG. 1) for connecting the second storage tank and the first tank 11, and a pump (not shown in FIG. 1) provided on the third pipe. In this way, any volume of the chloride salt solution or chloride salt powder can be supplied from the second storage tank to the first tank 11 by operating the pump.

[0030] Here, Fig. 2 is an explanatory diagram showing the form of carbon dioxide in water. In the figure, the horizontal axis indicates pH, and the vertical axis indicates the proportion of CO2 present (molar ratio). As shown in Fig. 2, carbon dioxide takes the form of bicarbonate ions at an extremely high ratio in water in the pH range of about 8.5 to 9. FIG. 3 is an explanatory diagram showing the relationship between CO2 loading and pH. CO2 loading is defined as the ratio between the number of moles of CO2 taken up in the amine solution and the number of moles of tertiary amine in the amine solution. In other words, the (amount of) CO2 loading is defined as the molar amount of CO2 absorbed by 1 mole of amine (mol-CO2 / mol-amine). In the figure, the horizontal axis indicates CO2 loading, and the vertical axis indicates pH. The graph shown in FIG. 3 clarifies the relationship between CO2 loading and pH, measured at amine solution concentrations of 10%, 20%, 30%, 40%, and 50% and CO2 concentrations of 99.9%, 40%, and 10%. In the graph shown in FIG. 3, the loading was less than 0.2 (y=8.7528x -0.041 , R 2 =0.9862) and 0.2 or more (y=-2.22959x+9.8678, R 2 =0.9097), two correlation equations are used to distinguish between the two cases. From the graph in Figure 3, it is thought that if the CO2 loading is set to 0.4 to 0.6, the pH range will be 8.5 to 9. Therefore, almost all of the CO2 becomes bicarbonate ions due to the reaction with tertiary amines in addition to the pH, and the reaction to carbonate in the next process can be efficiently carried out.

[0031] In other words, the pH of the amine solution when the chloride salt solution or chloride salt powder is supplied is preferably, for example, 8.5 to 9. In this way, CO2 is stably converted to bicarbonate ions in the amine solution. Such a pH of the amine solution can be obtained by setting the CO2 loading in the range of 0.4 to 0.6.

[0032] Therefore, in this embodiment, for example, when the CO2 loading reaches a condition of 0.4 to 0.6, it is preferable to stop diffusing bubbles containing CO2 gas into the amine solution, and then supply the chloride salt solution or chloride salt powder by the chloride salt supply means 14. Here, as described above, the CO2 loading is defined as the ratio (mol-CO2 / mol-amine) between the moles of CO2 taken into the amine solution and the moles of tertiary amine in the amine solution. In order to grasp the CO2 loading, for example, a first CO2 concentration meter G1 may be provided on the sixth pipe PL6 connected to the air diffusion plate 15, and a second CO2 concentration meter G2 may be provided at the exhaust port 12. Then, the ratio between the moles of CO2 taken into the amine solution calculated based on the CO2 concentration by the first CO2 concentration meter G1 and the CO2 concentration by the second CO2 concentration meter G2 and the moles of tertiary amine in the amine solution is calculated to obtain the CO2 loading. When the CO2 loading thus obtained is 0.4 to 0.6 as described above, CO2 is stably converted to bicarbonate ions in the amine solution.

[0033] The diffuser plate 15 is provided in the lower portion of the first tank 11, and diffuses small bubbles containing CO2 gas into the amine solution. The diffuser plate 15 is connected to, for example, a CO2-containing gas introduction pipe (sixth pipe PL6) provided with a blower B. Therefore, by operating the blower B, the gas containing CO2 gas discharged from the exhaust gas equipment through the CO2-containing gas introduction pipe can be introduced into the diffuser plate 15, and can be diffused into the amine solution as small bubbles from the diffuser plate 15 as described above.

[0034] The stirring blade 16 is provided above the air diffuser plate 15. After the chloride salt solution or the chloride salt powder is supplied to the amine solution in which the bubbles containing CO2 gas are sufficiently diffused, the stirring blade 16 stirs the mixed solution. The stirring blade 16 may be a disk turbine, a paddle, a screw, or the like. The stirring blade 16 is rotated by a motor M.

[0035] The thickening section 17 is provided below the air diffuser plate 15. The thickening section 17 has a cone shape with a horizontal cross-sectional area gradually decreasing toward the lower end of the first tank 11. In the thickening section 17, carbonates finally obtained by conversion are deposited as sludge, particulate solids, etc., as described later.

[0036] The rake 18 rotates within the thickening section 17 along the inclination of the thickening section 17. By rotating, the rake 18 imparts fluidity to carbonates in the form of sludge and particulate solids accumulated in the thickening section 17, and serves to uniformly and smoothly discharge them from the first discharge port 19 described below. The rake 18 is also rotated by a motor M.

[0037] The first discharge port 19 is provided at the bottom of the rake 18, and discharges carbonates that are converted by the supply of a chloride solution or chloride powder and deposited in the thickening section 17 to the outside of the first tank 11. The first discharge port 19 is preferably connected to a seventh pipe PL7 equipped with a pump P. In this way, the present device can smoothly discharge carbonates to the outside of the first tank 11.

[0038] (Reaction mechanism for converting CO2 to carbonate) The reaction mechanism by which the CO2 separation, capture and conversion apparatus 1 according to this embodiment having the configuration described above converts CO2 into carbonates can be explained as follows. First, the state in an amine solution containing a tertiary amine (NR1R2R3) is as follows: R1R2R3N+H2O ⇔ R1R2R3NH + +OH - H2O ⇔ H + +OH - The OH obtained from this state - reacts with CO2 to produce bicarbonate ions (HCO3 - ) is obtained (CO2 is converted to HCO3 - (transformed into OH - +CO2⇔HCO3 - If, for example, calcium chloride is added to this as a chloride salt, calcium carbonate (CaCO3) is produced (converted into calcium carbonate). Ca 2+ +HCO3 - ⇒ CaCO3+H +

[0039] In the case of the example shown above, theoretically, 1 mole of tertiary amine is required to separate and capture 1 mole of CO2 (Kei Teranishi and two others, "Computational Chemistry Study on CO2 Chemical Absorption Method: A Challenge to Energy and Environmental Issues," J.Compu.Chem.Jpn, Vol.15, No.2, pp.A15-A29, 2016, DOI:10.2477 / jccj.2016-0010). This is also confirmed by the experimental results (Figure 7) described later. In addition, the captured CO2 is converted to 1 mole of bicarbonate ion, and 1 mole of calcium chloride converts it to 1 mole of calcium carbonate. The maximum concentration of the calcium chloride solution is 745g / L. Therefore, it is recommended to perform the treatment by arbitrarily adjusting the concentrations of the tertiary amine, CO2, and chloride salt (e.g., calcium chloride) with the upper limit of the number of moles calculated from the maximum concentration of the calcium chloride solution.

[0040] Second embodiment Next, a CO2 separation, capture and conversion apparatus 2 according to a second embodiment will be described. FIG. 4 is a schematic diagram illustrating the configuration of a CO2 separation, capture and conversion apparatus 2 according to the second embodiment. As shown in FIG. 4, the CO2 separation, capture and conversion apparatus 2 according to the second embodiment is different from the first embodiment in that it has two tanks, unlike the first embodiment in which it has one tank. The second embodiment will be described below, focusing on the differences.

[0041] 4, the CO2 separation, capture and conversion device 2 according to the second embodiment includes a second tank 21 and a third tank 31. In the first embodiment, the first tank 11 absorbs CO2 with an amine solution and generates carbonate by supplying a chloride salt solution or chloride salt powder, whereas the second embodiment differs in that the second tank 21 absorbs CO2 with an amine solution and the third tank 31 generates carbonate by supplying a chloride salt solution or chloride salt powder.

[0042] In the first embodiment, which has one tank, the size and installation area of ​​the device can be reduced, and therefore the cost can be reduced. On the other hand, in the first embodiment, carbonates may accumulate on the diffuser plate 15, preventing proper diffusion and reducing the efficiency of CO2 absorption by the amine solution. In contrast, in the second embodiment, in which CO2 absorption and carbonate generation are performed in separate tanks, such a situation can be avoided.

[0043] The second tank 21 is a sealed tank capable of storing an amine solution containing a tertiary amine. The second tank 21 can be any tank made of metal such as SUS that is not corroded by the amine solution. The second tank 21 can be preferably cylindrical or rectangular, but is not limited thereto. The second tank 21 includes an exhaust port 12 , an amine solution supply means 13 , an air diffuser plate 15 , and a second exhaust port 22 .

[0044] The exhaust port 12 is provided in the gas phase portion of the second tank 21 . The amine solution supplying means 13 supplies the amine solution into the second tank 21 . The diffuser plate 15 is provided in the lower portion of the second tank 21 and diffuses small bubbles containing CO2 gas into the amine solution. The exhaust port 12, the amine solution supply means 13, and the air diffuser plate 15 in the second embodiment can be similar to those in the first embodiment. The second embodiment differs from the first embodiment in that the chloride salt solution or the chloride salt powder is not supplied to the tank (second tank 21) to which the amine solution is supplied. The amine solution supplying means 13 may include, for example, a first storage tank (not shown) for storing the amine solution, a second pipe (not shown) connecting the first storage tank and the second tank 21, and a pump (not shown) provided on the second pipe. In this way, an arbitrary volume of amine solution can be supplied from the first storage tank to the second tank 21 by operating the pump. The second outlet 22 is provided below the air diffuser plate 15, and discharges the amine solution in which bubbles containing CO 2 gas have been sufficiently diffused to the outside of the second tank 21.

[0045] The third tank 31 is connected to the second outlet 22 via the first pipe PL1, and is a tank to which the amine solution in which bubbles containing CO2 gas are sufficiently diffused is supplied via the first pipe PL1. The third tank 31 can be any tank made of metal such as SUS that is not corroded by the amine solution, chloride solution, or chloride powder. The third tank 31 can be preferably, but is not limited to, a cylindrical or square tube tank. The third tank 31 includes a chloride supply means 14 , an agitator 16 , a thickening section 17 , a rake 18 , and a third outlet 32 ​​.

[0046] The chloride salt supplying means 14 supplies a chloride salt solution or a chloride salt powder into the third tank 31 . After the chloride salt solution or chloride salt powder is supplied to the amine solution in which the CO2 gas-containing bubbles have been sufficiently diffused, the mixing blade 16 mixes the mixed solution. The enrichment section 17 has a cone shape with a horizontal cross-sectional area gradually decreasing toward the lower end of the third tank 31. The rake 18 rotates within the enrichment section 17 along the inclination of the enrichment section 17 . The chloride salt supplying means 14, the stirring blade 16, the concentrating section 17 and the rake 18 in the third embodiment can be similar to those in the first embodiment. The chloride salt supplying means 14 may include, for example, a second storage tank (not shown in FIG. 4) for storing a chloride salt solution or a chloride salt powder, a third pipe (not shown in FIG. 4) for connecting the second storage tank and the third tank 31, and a pump (not shown in FIG. 4) provided on the third pipe. In this way, any volume of the chloride salt solution or chloride salt powder can be supplied from the second storage tank to the third tank 31 by operating the pump.

[0047] The third discharge outlet 32 ​​is provided below the rake 18 and discharges to the outside the carbonates that have been converted by the supply of a chloride solution or chloride powder and that have accumulated in the thickening section 17 . The third outlet 32 ​​in the third embodiment may be similar to the first outlet 19 in the first embodiment. The third discharge port 32 is preferably connected to an eighth pipe PL8 equipped with a pump P. In this way, the present device can smoothly discharge the carbonate to the outside of the third tank 31.

[0048] As shown in Fig. 4, in the second embodiment, it is preferable to provide a liquid delivery mechanism 33 that delivers the amine solution recovered at the third outlet 32 ​​to the amine solution supply means 13. As shown in Fig. 4, an example of the liquid delivery mechanism 33 is a ninth pipe PL9 equipped with a pump P. One end of the ninth pipe PL9 is connected to the third outlet 32, and the other end is connected to the amine solution supply means 13, specifically, for example, to the first storage tank as described above. By operating the pump P, the amine solution recovered at the third outlet 32 ​​can be delivered to the amine solution supply means 13 via the ninth pipe PL9.

[0049] In the second embodiment, as in the first embodiment, it is preferable to mix the amine solution in which the bubbles containing CO2 gas are sufficiently diffused with the chloride salt solution or the chloride salt powder after the CO2 loading reaches a condition of 0.4 to 0.6. Therefore, in order to grasp the CO2 loading in the second tank 21, the second tank 21 may be provided with a first CO2 concentration meter G1 on the sixth pipe PL6 connected to the diffuser plate 15, as in the first tank 11, and a second CO2 concentration meter G2 at the exhaust port 12. Then, the ratio between the number of moles of CO2 taken into the amine solution calculated based on the CO2 concentration by the first CO2 concentration meter G1 and the CO2 concentration by the second CO2 concentration meter G2 and the number of moles of tertiary amine in the amine solution may be calculated to obtain the CO2 loading.

[0050] Third embodiment FIG. 5 is a schematic diagram illustrating the configuration of a CO2 separation, capture and conversion apparatus 3 according to the third embodiment. As shown in FIG. 5, in the CO2 separation capture and conversion device 3 according to the third embodiment, the second tank 21 is disposed at a high position, and the third tank 31 is disposed at a lower position than the second tank 21. In this way, the liquid can be transferred from the second tank 21 to the third tank 31 by utilizing the height difference between the second tank 21 and the third tank 31. Therefore, the CO2 separation capture and conversion device 3 according to the third embodiment can reduce the power cost for transferring the liquid. The first pipe PL1 may be equipped with a pump Pa, but an auxiliary pump with a smaller output can be used than when the second tank 21 and the third tank 31 are at the same height.

[0051] (Fourth embodiment) Fig. 6 is a schematic diagram for explaining the configuration of a CO2 separation, capture and conversion apparatus 4 according to the fourth embodiment. Note that the second tank 21 shown in the second embodiment is illustrated on the right side of Fig. 6, but it goes without saying that the first tank 11 shown in the first embodiment can also be applied. An example of the times measured by the measuring instrument 43 and the loading values ​​calculated at each time is shown on the left side of Fig. 6.

[0052] 6, the CO2 separation, capture and conversion device 4 according to the fourth embodiment may include a liquid sampling means 41 for sampling the mixed solution. The liquid sampling means 41 may include a sampling pipe 42 extending into the mixed solution and a pump P provided on the sampling pipe 42. The CO2 separation, capture and conversion device 4 according to the fourth embodiment may include at least one measuring instrument 43 selected from a density meter for measuring the density of the collected mixed solution, a weight meter for measuring the weight of the collected mixed solution, a viscometer for measuring the viscosity of the collected mixed solution, and an electrical conductivity meter for measuring the electrical conductivity of the collected mixed solution. These measuring instruments 43 are connected to the collection tube 42. The CO2 separation, capture and conversion device 4 according to the fourth embodiment may include a return means 44 that returns the collected mixed solution to the collection destination, i.e., the first tank 11 or the second tank 21, after measuring these physical properties. The return means 44 can be composed of a return pipe 45 connected from the measuring instrument 43 to the inside of the collection destination tank, and a pump P provided on the collection pipe 42.

[0053] Here, FIG. 7 is a graph that explains the change over time in the aeration time and the amount of CO2 absorption. In the figure, the horizontal axis indicates the aeration time (minutes), the vertical axis on the left indicates the amount of CO2 absorption (g), and the vertical axis on the right indicates the CO2 loading. "○" is a plot of the amount of CO2 absorption, and the numerical value is read on the vertical axis on the left. "□" is the value of the CO2 loading, and the numerical value is read on the vertical axis on the right. The amount of CO2 absorption was measured by taking 250 mL of the amine solution. The amine solution contains MDEA as a tertiary amine. FIG. 8 also shows the mass capacity coefficient k L 1 is a graph showing the calculation of the material capacity coefficient k LHere, a refers to a parameter used for mass transfer between gas and liquid, such as gas absorption and diffusion. The horizontal axis in Fig. 8 indicates the above-mentioned time (variable t in Equation 1 (CO2 absorption operation time with the aeration start time being zero)), and the vertical axis indicates Ln((Cs-C) / Cs) on the left side of Equation 1. Here, the concentration C of absorbed CO2 in the absorbing liquid is the concentration value obtained by dividing the CO2 absorption amount in Fig. 7 by the amount of absorbing liquid, and the maximum absorption concentration obtained by dividing the maximum absorption amount by the amount of absorbing liquid is Cs. Fig. 8 shows the mass capacity coefficient calculated for the section (0-60 minutes) where the amount of CO2 absorption in Fig. 7 is constant, and the slope of the straight line shown in Fig. 8 is the mass capacity coefficient k L a. Figure 8 is a plot created by Equation 1 using the aforementioned absorption concentrations C and Cs in the initial 60 minutes when the CO2 absorption rate is almost constant in the data of Figure 7. The straight line that approximates the plot shown in Figure 8 is y = -0.0135x, and the square correlation coefficient (coefficient of determination) is R 2 =0.9932, which indicates a high correlation.

[0054]

number

[0055] Returning to Figure 7, we continue the explanation. As shown in Figure 7, it was confirmed that the CO2 absorption amount was saturated with an aeration time of 120 to 180 minutes. In addition, as is clear from the graph in Figure 7, if the CO2 loading is 0.1 or more, it is possible to measure the weight in 1g units, and even if the CO2 loading is less than 0.1, it is fully possible to measure the weight in 0.1g units.

[0056] Furthermore, as shown in Figure 7, the CO2 loading, defined as the ratio of the number of moles of separated and captured CO2 to the number of moles of tertiary amine, was 1.0 when the absorption amount was saturated. This shows that, in the case of the tertiary amine (MDEA) used in this experiment, 1 mole of amine is required to separate 1 mole of CO2.

[0057] As described with reference to FIG. 7 and FIG. 8, when the CO2 loading is 0.1 or more, it is possible to detect the weight in 1 gram units, and even when the CO2 loading is 0.1 or less, it is possible to measure the weight with an accuracy of 0.1 gram, so that it is possible to monitor the CO2 loading by measuring the weight and density. Therefore, the above-mentioned density meter and weight meter can be used to confirm and determine the target range of CO2 loading, 0.4 to 0.6. For example, as shown in the right and left diagrams of FIG. 6, the density and weight of the mixed solution are measured at specific times using a measuring instrument 43 (density meter, weight meter) and the CO2 loading value is calculated. For example, the measurement is continued such that the CO2 loading value at time t1 is 0.1, the CO2 loading value at time t2 is 0.2, and the CO2 loading value at time t3 is 0.35.... This is continued until the CO2 loading value reaches the condition of 0.4 to 0.6. Then, for example, when the CO2 loading value becomes 0.4 or more at time tN (0.47 in the example of FIG. 6), the diffusion of bubbles containing CO2 gas by the air diffuser plate 15 is stopped (CO2 absorption operation is stopped).

[0058] It is also known that there is a high correlation between the concentration of tertiary amines in an amine solution and the viscosity (Fujita, et al., "Changes in Electrical Conductivity Due to CO2 Absorption in Butyethanolamine Aqueous Solution and Methyldiethanolamine Aqueous Solution at 313 K," Analytical Chemistry, Vol. 68, No. 9, pp. 647-655, 2019). Figure 9 is a graph showing the relationship between the concentration of the absorbing liquid (amine solution) and the viscosity. In the figure, the horizontal axis shows the absorbing liquid concentration (mass%) and the vertical axis shows the viscosity (mPa·s). In Figure 9, the liquid temperature of 20 to 25°C was analyzed by the present inventors, and the liquid temperature of 40°C is based on the above literature. When the liquid temperature is 20 to 25°C, y=e 0.0424x , R 2= 0.9908, and when the liquid temperature is 40°C, y = 0.65e 0.0369x , R 2 =0.9938.

[0059] In addition, according to the above-mentioned document, it is shown that there is a correlation between the concentration of the amine solution and the electrical conductivity. Here, Fig. 10 is a schematic diagram illustrating another configuration of the CO2 separation, capture and conversion device 4 according to the fourth embodiment. 10, the above-mentioned viscometer or electrical conductivity meter is provided as a measuring instrument 43, and by measuring these, it is possible to monitor the change in concentration of the amine solution (change in the concentration of tertiary amine in the amine solution). When the concentration of tertiary amine in the amine solution falls below 10 mass%, the efficiency of separation, capture, and conversion of CO2 drops significantly, so it is advisable to stop the device and replace the amine solution.

[0060] Furthermore, the amine solution, especially water, decreases due to the recovery of carbonate sludge. Therefore, it is preferable that the first tank 11 described in the first embodiment and the second tank 21 described in the second embodiment are provided with at least one of a manometer and a liquid level gauge. In this way, after the carbonate recovery, the liquid volume of the amine solution in the first tank 11 or the second tank 21 can be confirmed before the operation for separation, capture, and conversion of CO2 is performed again.

[0061] Therefore, for example, before diffusing bubbles containing CO2 gas from the diffuser plate 15, the liquid level of the amine solution is measured using the manometer or liquid level gauge described above, and if the liquid level is lower than a specified value, the first tank 11 or the second tank 21 is replenished with water or amine solution to make up for the decrease, thereby maintaining a constant amount of amine solution.

[0062] Fifth embodiment Next, a description will be given of a CO2 separation, capture and conversion apparatus according to the fifth embodiment. Fig. 11 is a schematic diagram for explaining a CO2 separation, capture and conversion apparatus 5 according to the fifth embodiment. As shown in FIG. 11, the CO2 separation capture and conversion device 5 according to the fifth embodiment is provided with the first tank 11 in series in multiple stages. In this CO2 separation capture and conversion device 5, the exhaust port 12 of the first tank 11 in the first stage as viewed from the exhaust gas equipment EGE and the air diffuser plate 15 of the first tank 11 in the second stage are connected by the fourth pipe PL4. The exhaust port 12 of the first tank 11 in each stage is provided with a switching valve (not shown) so that connection to the first tank 11 in the second stage and opening to the atmosphere can be selected arbitrarily. This CO2 separation capture and conversion device 5 adopts this configuration for the front and rear stages over multiple stages. The number of stages of the first tank 11 in this CO2 separation capture and conversion device 5 is not particularly limited, but can be, for example, four or more stages. The exhaust port 12 of the first tank 11 in the last stage as viewed from the exhaust gas equipment EGE may be connected to the air diffuser plate 15 of the first tank 11 in the first stage via the fourth pipe PL4.

[0063] FIG. 12 is an explanatory diagram illustrating a configuration example of a CO2 separation, capture and conversion apparatus 5 according to the fifth embodiment. As shown in Fig. 12, in the CO2 separation capture conversion device 5 according to the fifth embodiment, for example, when the first tank 11 is provided in four stages, the last first tank 11 is supplied with an amine solution as a reserve tank. As for the three first tanks 11 arranged in the stages before that, the exhaust port 12 of the first tank 11 in the first stage is connected to the diffuser plate 15 of the first tank 11 in the second stage by the fourth pipe PL4, and the exhaust port 12 of the first tank 11 in the second stage is connected to the diffuser plate 15 of the first tank 11 in the third stage by the fourth pipe PL4, as viewed from the exhaust gas equipment EGE. The exhaust port 12 of the first tank 11 in the third stage is not connected to the diffuser plate 15 of the first tank 11 that is the reserve tank for the fourth stage, so that the treated gas can be exhausted from the exhaust port 12. Further, the amine solution is appropriately supplied to each first tank 11 from a first storage tank not shown in Fig. 12. The chloride salt solution or chloride salt powder is appropriately supplied from a second storage tank ST2 by a pump P.

[0064] In this configuration, the CO2 separation, capture and conversion device 5 introduces the CO2-containing gas discharged from the exhaust gas equipment EGE into the diffuser plate 15 of the first tank 11 of the first stage, and the CO2 is diffused from the diffuser plate 15 into the amine solution to absorb the CO2 in the CO2-containing gas. The CO2 that could not be absorbed by the amine solution of the first tank 11 of the first stage is introduced from the exhaust port 12 of the first tank 11 of the first stage through the fourth pipe PL4 to the diffuser plate 15 of the first tank 11 of the second stage, and is diffused from the diffuser plate 15 into the amine solution to absorb the CO2 in the CO2-containing gas. The CO2 concentration in the CO2-containing gas supplied to the first tank 11 of the second stage is treated with the amine solution of the first tank 11 of the first stage, so that it is lower than the CO2 concentration in the CO2-containing gas supplied to the first tank 11 of the first stage. The first tank 11 of the second stage and the first tank 11 of the third stage are also configured in the same way, and treat the CO2-containing gas in the same way. The treated gas exhausted from the exhaust port 12 of the third-stage first tank 11 contains almost no CO2 gas (CO2 is removed by 95 to 100%) because it has been treated with the amine solution contained in the first to third-stage first tanks 11. Therefore, the treated gas exhausted from the exhaust port 12 of the third-stage first tank 11 can be released into the atmosphere.

[0065] FIG. 13 is an explanatory diagram for explaining an example of a specific operation method of the CO2 separation, capture and conversion apparatus 5 according to the fifth embodiment. As shown in FIG. 13, the CO2 separation, capture and conversion apparatus 5 according to the fifth embodiment has four first tanks 11. The first lap, 1st stage, 2nd stage, 3rd stage, 4th stage (spare tank) Let us assume that.

[0066] The supply of CO2-containing gas to the amine solution in the first tank 11 in the first stage of the first round is stopped when the CO2 loading condition becomes 0.4 to 0.6, and the switching valve is switched to make the first tank 11, which was the second stage in the first round, the first stage in the second round. Similarly, the first tank 11, which was the third stage in the first round, becomes the second stage in the second round, the first tank 11, which was the fourth stage (reserve tank) in the first round, becomes the third stage in the second round, and the first tank 11, which was the first stage in the first round, becomes the fourth stage (reserve tank) in the second round. That is, from the first tank 11 closest to the exhaust gas equipment EGE, The second lap, 4th stage (spare tank), 1st stage, 2nd stage, 3rd stage Let us assume that.

[0067] While processing the first, second, and third stages of the second round is being carried out, the next processing is carried out on the first tank 11 (spare tank) in the fourth stage of the second round, that is, the first tank 11 that was in the first stage of the first round. First, a chloride solution or chloride powder is supplied to the first tank 11, which was the first stage of the first rotation, and stirred with a stirring blade 16 (not shown in Fig. 13), causing the CO2 absorbed in the amine solution (almost all of this CO2 has become bicarbonate ions) to react with the chloride, converting it to carbonate. The carbonate sludge is then discharged from a first discharge port 19 (not shown in Fig. 13) and stored in another container (not shown).

[0068] Since the first tank 11 in the first stage of the second cycle is the first tank 11 in the second stage of the first cycle, a certain amount of CO2 has already been supplied to the amine solution contained therein, and bicarbonate ions have been generated. The first tank 11 in the second stage of the second round is the first tank 11 in the third stage of the first round. It is considered that almost all of the CO2 is absorbed in the first tank 11 in the second stage of the first round, and that almost no CO2 is carried over to the first tank 11 in the third stage of the first round. Therefore, it is considered that the first tank 11 in the second stage of the second round has a sufficiently high CO2 absorption capacity. Considering that CO2 can also be absorbed in the first tank 11 in the third stage of the first cycle, the gas exhausted from the exhaust port 12 of the first tank 11 in the third stage of the first cycle is considered to have almost 100% (95-100%) of CO2 removed.

[0069] Then, when the CO2 loading condition becomes 0.4 to 0.6, the supply of CO2-containing gas to the amine solution in the first tank 11 of the first stage of the second round is performed by switching the switching valve in the same manner as in the second round, starting from the first tank 11 closest to the exhaust gas equipment EGE. The third lap, 3rd stage, 4th stage (spare tank), 1st stage, 2nd stage Let us assume that. Thereafter, the same process is repeated. According to the CO2 separation, capture and conversion apparatus 5 of the fifth embodiment, since the first tanks 11 are provided in series in multiple stages, separation, capture (absorption) of CO2, and conversion to carbonates can be performed more efficiently.

[0070] Sixth embodiment FIG. 14 is a schematic diagram illustrating a CO2 separation, capture and conversion apparatus 6 according to the sixth embodiment. As shown in Fig. 14, the CO2 separation, capture and conversion apparatus 6 according to the sixth embodiment is provided with multiple parallel stages of the first tanks 11 in the first embodiment shown in Fig. 1. In other words, the CO2 separation, capture and conversion apparatus 6 according to the sixth embodiment is configured in parallel with the CO2 separation, capture and conversion apparatus 5 configured in multiple series stages described in the fifth embodiment. The CO2 separation, capture and conversion apparatus 6 according to the sixth embodiment is provided with the first tanks 11 in parallel and multiple stages, and therefore can convert CO2 into carbonates more efficiently than in the fifth embodiment.

[0071] Seventh embodiment FIG. 15 is a schematic plan view illustrating a CO2 separation, capture and conversion apparatus 7 according to the seventh embodiment. As shown in Fig. 15, the CO2 separation, capture and conversion device 7 according to the seventh embodiment includes the second tanks 21 of the second embodiment shown in Fig. 4 in multiple stages in series. Note that Fig. 15 illustrates a configuration including four second tanks 21, but is not limited to this. Also, Fig. 15 illustrates a configuration including a third tank 31 for each second tank 21, but it is also possible to use a configuration including one third tank 31 for four second tanks 21.

[0072] In the second tank 21 shown in FIG. 15, like the first tank 11 shown in FIG. 14, the second tank 21 closest to the exhaust gas equipment EGE is The first lap, 1st stage, 2nd stage, 3rd stage, 4th stage (spare tank) Let us assume that.

[0073] The supply of CO2-containing gas to the amine solution in the second tank 21 in the first stage of the first cycle is stopped when the CO2 loading condition becomes 0.4 to 0.6, and the amine solution in which the CO2-containing gas is sufficiently diffused is sent to the third tank 31 from the second outlet 22 of the second tank 21 through the first pipe PL1. Then, a chloride salt solution or chloride salt powder is supplied into the third tank 31 by the chloride salt supply means 14 not shown in FIG. 15, and the mixed solution of the amine solution and the chloride salt solution or chloride salt powder is stirred with the stirring blade 16 (see FIG. 4) to generate carbonate. Then, this carbonate is discharged to the outside of the device from the third outlet 32 ​​provided at the bottom of the rake 18 in the concentration section 17 (see FIG. 4) of the third tank 31 while being stirred with the rake 18 (see FIG. 4).

[0074] Also, the switching valve is switched so that the second tank 21, which was the second stage in the first revolution, becomes the first stage in the second revolution. Similarly, the second tank 21, which was the third stage in the first revolution, becomes the second stage in the second revolution, the second tank 21, which was the fourth stage (reserve tank) in the first revolution, becomes the third stage in the second revolution, and the second tank 21, which was the first stage in the first revolution, becomes the fourth stage (reserve tank) in the second revolution. That is, from the second tank 21 closest to the exhaust gas equipment EGE, The second lap, 4th stage (spare tank), 1st stage, 2nd stage, 3rd stage Let us assume that.

[0075] Since the second tank 21 in the first stage of the second cycle is the second tank 21 in the second stage of the first cycle, a certain amount of CO2 has already been supplied to the amine solution contained therein, and bicarbonate ions have been generated. The second tank 21 in the second stage of the second round is the second tank 21 in the third stage of the first round. It is considered that almost all of the CO2 is absorbed in the second tank 21 in the second stage of the first round, and that almost no CO2 is carried over to the second tank 21 in the third stage of the first round. Therefore, it is considered that the second tank 21 in the second stage of the second round has a sufficiently high CO2 absorption capacity. Considering that CO2 can also be absorbed in the second tank 21 in the third stage of the first cycle, the gas exhausted from the exhaust port 12 of the second tank 21 in the third stage of the first cycle is considered to have almost 100% (95 to 100%) of CO2 removed.

[0076] Then, the supply of CO2-containing gas to the amine solution in the second tank 21 in the first stage of the second cycle is stopped when the CO2 loading condition becomes 0.4 to 0.6, for example, and the amine solution in which the CO2-containing gas has been sufficiently diffused is sent from the second outlet 22 of the second tank 21 via the first piping PL1 to the third tank 31, and processed in the same manner as in the first cycle. In addition, the switching valve was switched in the same way as in the second round, and the second tank 21, which is closest to the exhaust gas equipment EGE, was replaced with The third lap, 3rd stage, 4th stage (spare tank), 1st stage, 2nd stage Let us assume that. Thereafter, the same process is repeated. According to the CO2 separation, capture and conversion apparatus 7 of the seventh embodiment, since the second tanks 21 are provided in series in multiple stages, separation, capture (absorption) of CO2, and conversion to carbonates can be performed more efficiently.

[0077] Eighth embodiment FIG. 16 is a schematic diagram illustrating a CO2 separation, capture and conversion apparatus 8 according to the eighth embodiment. As shown in Fig. 16, the CO2 separation, capture and conversion system 8 according to the eighth embodiment is provided with the second tanks 21 in the second embodiment shown in Fig. 4 in multiple parallel stages. That is, as shown in Fig. 16, the CO2 separation, capture and conversion system 8 according to the eighth embodiment is provided with the configuration in which the second tanks 21 described in the seventh embodiment are provided in multiple series stages in parallel. The CO2 separation, capture and conversion device 8 according to the eighth embodiment is provided with the second tanks 21 in parallel multiple stages, and therefore can convert CO2 into carbonates more efficiently than in the seventh embodiment.

[0078] Ninth embodiment In this embodiment, an ion exchange resin column (not shown) can be provided for reusing the amine solution after the formation of carbonate. In this way, chlorine contained in the amine solution can be removed by the ion exchange resin by adding a chloride salt such as calcium chloride. At the same time, the pH of the amine solution can be increased again by the generated hydroxide ions when it is reused. The ion exchange resin column can be provided, for example, on the ninth pipe PL9. In this way, chlorine can be suitably removed when the recovered amine solution returns to the amine solution supply means 13.

[0079] Tenth embodiment Next, a CO2 separation, capture and conversion method according to the tenth embodiment will be described with reference to Fig. 17. Fig. 17 is a flow diagram illustrating the details of the CO2 separation, capture and conversion method according to the tenth embodiment. The CO2 separation, capture and conversion method according to the tenth embodiment uses any one of the CO2 separation, capture and conversion devices 1 to 8 described above. As shown in FIG. 17, the CO2 separation, capture and conversion method according to the tenth embodiment includes an amine solution supplying step S1, an aeration step S2, a chloride salt supplying step S3, a stirring step S4, and a discharging step S5.

[0080] In the amine solution supplying step S1, the amine solution is supplied into tanks (first tank 11, second tank 21). The amine solution can be supplied by the amine solution supplying means 13 described above. In the aeration step S2, bubbles containing CO 2 gas are diffused from the aeration plate 15 into the amine solution.

[0081] In the chloride salt supplying step S3, a chloride salt solution or a chloride salt powder is supplied to the amine solution in which bubbles containing CO2 gas have been sufficiently diffused (for example, the CO2 loading has reached 0.4 to 0.6). The chloride salt solution or the chloride salt powder can be supplied by the above-mentioned chloride salt supplying means 14. The chloride salt solution or the chloride salt powder is supplied to the first tank 11 or the third tank 31 depending on the above-mentioned embodiment.

[0082] In the stirring step S4, a mixed solution of the amine solution, in which bubbles containing CO2 gas have been sufficiently diffused, and the chloride salt solution or the chloride salt powder is stirred by the stirring blade 16. The stirring step S4 is performed in the first tank 11 or the third tank 31 depending on the above-mentioned embodiment. In the discharge step S5, the carbonate converted in the mixed solution obtained by supplying the chloride salt solution or the chloride salt powder to the amine solution in which the bubbles containing CO2 gas have been sufficiently diffused is concentrated in the concentrating section 17, and then discharged to the outside of the apparatus. The discharge step S5 is also performed at the first outlet 19 of the concentrating section 17 of the first tank 11 or the third outlet 32 ​​of the concentrating section 17 of the third tank 31, depending on the above-mentioned correspondence.

[0083] (effect) The CO2 separation, capture and conversion devices 1 to 8 and the CO2 separation, capture and conversion method according to each of the embodiments described above differ from conventional technology in that they heat the amine solution at 110 to 130°C to recover CO2 from the amine solution and do not require a regeneration tower to regenerate the amine solution, resulting in lower operating costs, a smaller facility scale than conventional methods, and the ability to convert CO2 into a resource. EXAMPLES

[0084] Next, the CO2 separation, capture and conversion apparatus and the CO2 separation, capture and conversion method according to the present invention will be specifically described using examples.

[0085] (1) Chemical absorption experiment using tertiary amines Figure 18 is an explanatory diagram (photograph) explaining the state of a chemical absorption experiment using a tertiary amine. In this experiment, CO2 gas with a purity (concentration) of 99.99% was used. As shown in Fig. 18, 250 mL of absorbing solution (amine solution containing MDEA as a tertiary amine) was filled into a gas washing bottle (sealed container) (inner diameter 49 mm × water depth 170 mm). The MDEA concentrations were 10 mass%, 20 mass%, 30 mass%, 40 mass%, and 50 mass%. The photograph in Fig. 18 was taken 5 minutes after the start of aeration of the CO2-containing gas for an absorbing solution concentration (MDEA concentration) of 10 mass%. An experiment on the absorption of CO2-containing bubbles by CO2-containing gas (concentration 99.99%) was carried out in a three-stage series system with increased water depth. The gas washing bottles were arranged in stages 1, 2, and 3 from the left side, where the CO2-containing gas was introduced.

[0086] The CO2-containing gas introduced into the first stage was supplied through a glass tube to the diffuser plate installed at the bottom of the first stage gas washing bottle, and CO2-containing bubbles were generated from this diffuser plate. A large number of bubbles were generated in the first stage gas washing bottle, which caused a jet of CO2-containing bubbles to be generated. The bubbles were supplied from the gas phase at the top of the first gas washing bottle through a connecting pipe to the diffuser plate at the bottom of the second gas washing bottle, and CO2-containing bubbles were generated from this diffuser plate. The second gas washing bottle had fewer bubbles than the first, and as a result, the jet of CO2-containing bubbles was also reduced.

[0087] The bubbles are supplied from the gas phase at the top of the second gas washing bottle through a connecting pipe to a diffuser plate installed at the bottom of the third gas washing bottle, and CO2-containing bubbles are generated from this diffuser plate. When Figure 18 was photographed, no bubbles were generated in the third gas washing bottle. After Figure 18 was photographed, a small amount of bubbles were slowly generated from the diffuser plate installed at the bottom of the third gas washing bottle and were discharged to the outside as treated gas from the upper gas phase. When the treated gas was checked, its composition was found to be almost zero CO2 concentration and mostly nitrogen gas. As described above, this test was performed with an absorption solution concentration (MDEA concentration) of 10 to 50 mass%, and it was confirmed that almost all of the CO2 can be separated and captured efficiently if the concentration is in the range of 10 to 40 mass%, as described below.

[0088] FIG. 19 is a photograph showing the state in which an aqueous calcium chloride solution was added to the absorbing liquid that had absorbed CO2. As shown in Figure 19, it was confirmed that calcium carbonate (white sludge) is generated by adding a calcium chloride solution to the absorption liquid that has absorbed CO2. This is just one example, but with the aeration method, it is not necessary to use tall or large facilities as in the conventional chemical absorption method, and it is also not necessary to have a regeneration tower that regenerates the amine solution by heating it to 110-130℃, so it was confirmed that operating costs can be reduced.

[0089] (2)CO2 separation and capture performance Fig. 20 is a graph showing the change over time in the removal rate for each concentration of the absorbing solution. In the figure, the horizontal axis indicates the aeration time (minutes) and the vertical axis indicates the removal rate (%). Note that Fig. 20 shows the CO2 removal rate calculated for an aeration time of 0 to 240 minutes for an amine solution with an MDEA concentration of 10 to 50 mass% in the experimental system of (1) above.

[0090] As shown in FIG. 20, except for when the MDEA concentration in the absorbing solution was 50% by mass, a regularity was confirmed in the CO2 reduction trend (removal rate) under other absorbing solution concentration conditions, i.e., when the MDEA concentration was 10 to 40% by mass. As shown in Figure 20, when the MDEA concentration in the absorption solution was 50 mass%, the removal rate was low from the beginning, and the trend was different from that of 10 to 40 mass%. This was presumed to be due to the increase in bubble size caused by the high viscosity when the MDEA concentration was 50 mass%, and the effect of viscosity on the transfer coefficient. It was confirmed that when the MDEA concentration was 10 to 40 mass%, it was more efficient than when it was 50 mass%, and almost all of the CO2 could be separated and captured (in the results shown in Figure 20, the removal rate exceeded 90% at the most at the time of 240 minutes of aeration time).

[0091] (3) Conditions for converting captured CO2 into calcium carbonate (part 1) The form of carbon dioxide in water was previously described with reference to Figure 2. Also, the relationship between CO2 loading and pH was described with reference to Figure 3. As described with reference to FIG. 2, carbonic acid takes the form of bicarbonate ions at an extremely high rate in water in the pH range of about 8.5 to 9. Figure 3 shows the relationship between CO2 loading and pH measured at amine solution concentrations of 10 mass%, 20 mass%, 30 mass%, 40 mass%, and 50 mass%, and CO2 concentrations of 99.9 mass%, 40 mass%, and 10 mass%. Figure 3 shows a high correlation between CO2 loading and pH, regardless of the concentration of the absorption solution and CO2. In addition, from the relationship between the pH of about 8.5 to 9 shown in Figure 2 and the CO2 loading of 0.4 to 0.6 shown in Figure 3, it was estimated that CO2 would be stably converted to bicarbonate ions in the absorption solution if the CO2 loading was 0.4 to 0.6 and the pH was 8.5 to 9. Therefore, the following study was carried out.

[0092] (4) Conditions for converting captured CO2 into calcium carbonate (part 2) FIG. 21 is a graph showing the relationship between CO2 loading, conversion rate to calcium carbonate, and pH. In the graph, the horizontal axis shows CO2 loading, the vertical axis on the left shows conversion rate to calcium carbonate (%), and the vertical axis on the right shows pH. The dotted line in the graph is an approximation line for the conversion rate, y = -143.67x + 167.79, R 2=0.8197. As shown in Figure 21, it was confirmed that the conversion of captured CO2 to calcium carbonate can be controlled by the CO2 loading and pH conditions. In addition, the results showed that conversion close to 100% was possible when the CO2 loading was in the range of 0.45 to 0.5 (pH range of 8.72 to 8.76).

[0093] Fig. 22 is a graph showing the particle size distribution of the obtained calcium carbonate particles. In the figure, the horizontal axis indicates particle diameter (μm), the left vertical axis indicates frequency (%), and the right vertical axis indicates cumulative passing amount (%). The particle size distribution of the obtained calcium carbonate particles was obtained by dispersing the recovered calcium carbonate dry powder sample in pure water and subjecting it to a laser diffraction particle size distribution measuring device (LA-950 manufactured by Horiba, Ltd.). The average diameter was 6.4 μm, the minimum diameter was 2 μm, and the maximum diameter was 17.4 μm.

[0094] From the results shown in Figures 21 and 22, it was considered advisable to carry out an aeration treatment to allow the amine solution to absorb CO2, and then stop the aeration treatment when the CO2 loading reaches a range of 0.4 to 0.6, and most preferably 0.45 to 0.5, and then add calcium chloride (chloride salt) to generate calcium carbonate (carbonate salt).

[0095] (5) CO2 capture and resource conversion Fig. 23 is a graph showing the relationship between CO2 loading and CO2 removal rate. In the figure, the horizontal axis shows CO2 loading, and the vertical axis shows removal rate (%). Note that Fig. 23 shows the relationship between CO2 loading and CO2 removal rate for an absorption liquid (amine solution) with an MDEA concentration of 10 to 40 mass%. As shown in Figure 23, it was confirmed that the CO2 removal rate is close to 100% when the CO2 loading is 0.5 or less. It was also confirmed that the CO2 removal rate is close to 100% even when the CO2 loading is 0.6. Therefore, if operation is performed under these conditions, all or almost all of the CO2 sent to this CO2 separation and conversion device can be converted into calcium carbonate.

[0096] (6) Power calculation for separation and recovery From the experiment to confirm the aeration time and the amount of CO2 absorbed (see Figure 24), the relationship between the concentration of the absorbing liquid (the concentration of the amine solution) and the absorption limit amount of CO2 (see Figure 25) was obtained. Figure 24 is a graph showing the relationship between the aeration time and the amount of CO2 absorbed. In the figure, the horizontal axis shows the aeration time (minutes), and the vertical axis shows the amount of absorption (g). The slope of each line graph in Figure 24 represents the removal rate. From the results shown in Figure 24, it can be seen that when the concentration of the absorbing liquid is 10 to 40 mass%, the removal amount becomes saturated when the aeration time exceeds 150 minutes. When the concentration of the absorbing liquid is 50 mass%, the removal amount does not become saturated but increases even when the aeration time exceeds 150 minutes. Figure 25 is a graph showing the relationship between the concentration of the absorbing liquid and the absorption limit amount of CO2. In the figure, the horizontal axis shows the concentration of the absorbing liquid (mass%), and the vertical axis shows the absorption limit amount (t-CO2 / m 3 The dotted line in the figure is an approximate straight line of the absorption limit amount versus the absorbing solution concentration, y = 0.0031x, R 2 = 0.9972. As shown in Fig. 25, it was confirmed that there is a highly linear relationship between the concentration of the absorbing solution and the absorption limit amount of CO2.

[0097] Using these as reference, we carried out a trial calculation of the power required for separation and recovery. Daily CO2 emissions: W CO2 (t-CO2 / day) Absorbent concentration: C (mass%) CO2 absorption limit: M S (t-CO2 / m 3 -Absorption fluid) CO2 loading: 0.5 Aeration power density: 37W / m 3 ≒40W / m 3 (*The mixing power density in the reactor due to aeration is calculated by multiplying the turbulent energy dissipation rate obtained by multiphase flow analysis using CFD (Computational Fluid Dynamics) by the density of the liquid phase.)

[0098] The required amount of absorption liquid is W CO2 / M S (m 3 -absorption fluid / day). Because the CO2 loading is 0.5,

[0099]

number

[0100] W per day CO2 The power required to process (t-CO2 / day) is:

[0101]

number

[0102] This is W CO2 When divided by the power required to process 1 ton of CO2 (t-CO2 / day) and converted to power per ton of CO2, it becomes 2.23 / C (GJ / t-CO2). Therefore, when the concentration of the absorbing solution is 40% by mass, it is approximately 0.056 GJ / t-CO2, and when it is 10% by mass, it is 0.223 GJ / t-CO2. In either case, compared to the 4 GJ / t-CO2 that is the standard for power consumption in the conventional amine absorption method, CO2 separation and capture can be achieved with extremely low power. Even if the blower efficiency is 50%, it will be approximately 0.11 to 0.45 GJ / t-CO2, achieving significant energy savings.

[0103] (7) Evaluation results when using calcium chloride powder An evaluation was performed when calcium chloride powder was used instead of calcium chloride aqueous solution. Calcium chloride powder was added to an absorbing solution (concentration 10 to 40 mass%) that had absorbed CO2, and the CO2 absorption rate, conversion rate to calcium carbonate (simply indicated as "conversion rate" in Figure 26), and CO2 loading were obtained. The results are shown in Figure 26. Figure 26 is a graph showing the relationship between the absorbing solution concentration and the CO2 absorption rate, conversion rate, and CO2 loading when calcium chloride powder is used. In the figure, the horizontal axis indicates the absorbing solution concentration (mass%), the left vertical axis indicates the CO2 absorption rate and conversion rate (%), and the right vertical axis indicates the CO2 loading (-). As shown in Figure 26, when the CO2 loading (□) was about 0.5, the absorption rate (○) in the absorbing solution of each concentration was almost 100%. In addition, when calcium chloride powder was added, the conversion rate (△) of the captured CO2 to calcium carbonate was 96% or more.

[0104] The CO2 separation, capture and conversion apparatus and the CO2 separation, capture and conversion method according to the present invention have been described in detail above with reference to the embodiments and examples. However, the present invention is not limited to the above-described embodiments and examples, and includes various modified examples. For example, the above-described embodiments have been described in detail to easily explain the present invention, and are not necessarily limited to those having all of the configurations described. In addition, it is possible to replace a part of the configuration of one embodiment with the configuration of another embodiment, and it is also possible to add the configuration of another embodiment to the configuration of one embodiment. In addition, it is possible to add, delete, or replace a part of the configuration of each embodiment with another configuration.

[0105] For example, although not shown, a modification of the sixth embodiment may be such that the first tank 11 in the first embodiment shown in FIG. 1 is provided in a single parallel stage. Furthermore, for example, as a modified example of the seventh embodiment, although not shown, the second tank 21 in the second embodiment shown in FIG. 4 may be provided in a single parallel stage. Even in these modified embodiments, unlike the conventional technology, there is no need for a regeneration tower to heat the amine solution at 110 to 130°C to recover CO2 from the amine solution and regenerate the amine solution, so that the operating costs are low, the scale of the equipment is smaller than in the past, and CO2 can be converted into a resource. [Explanation of symbols]

[0106] 1~8 CO2 separation and capture equipment 11 First Tank 12 Exhaust port 13 Amine solution supply means 14. Chloride salt supply means 15 Air diffuser 16 Stirring blade 17 Concentration section 18 Rake 19 1st outlet 21 Second Tank 22 2nd outlet 31 Third Tank 32 3rd outlet 33 Liquid delivery mechanism 41 Liquid sampling means 42 Collection tube 43 Measuring Instruments 44 Return Method 45 Return pipe B Blower EGE exhaust gas equipment G1 1st CO2 concentration meter G2 Secondary CO2 Concentration Meter Medium motor P-Pump PL1 First pipe PL4 4th pipe PL6 6th pipe PL7 7th pipe PL8 8th pipe PL9 9th pipe S1 Amine solution supply process S2 aeration process S3 Chloride salt supply process S4 Stirring process S5 discharge process

Claims

1. a first tank having a sealable structure capable of containing an amine solution containing a tertiary amine; an exhaust port provided in a gas phase portion of the first tank; an amine solution supplying means for supplying the amine solution into the first tank; a chloride salt supplying means for supplying a chloride salt solution or a chloride salt powder into the first tank; A CO 2 gas is introduced into the amine solution in the lower portion of the first tank. ２ A diffusion plate for diffusing bubbles containing gas; The CO ２ a stirring blade for stirring the mixed solution of the chloride salt solution or the chloride salt powder after supplying the chloride salt solution or the chloride salt powder to an amine solution in which bubbles containing gas have been sufficiently diffused; a cone-shaped concentration section provided below the air diffuser plate and having a horizontal cross-sectional area gradually decreasing toward a lower end of the first tank; A rake that rotates in the enrichment section along the inclination of the enrichment section; a first outlet provided at a lower portion of the rake for discharging carbonate that is converted by the supply of the chloride salt solution or the chloride salt powder and deposited in the thickening section to the outside; CO ２ Separation, recovery and conversion equipment.

2. A second tank and a third tank are provided, The second tank is A sealed tank capable of storing an amine solution containing a tertiary amine, The second tank is An exhaust port provided in a gas phase portion of the second tank; an amine solution supplying means for supplying the amine solution into the second tank; The second tank is provided in a lower portion thereof with a CO ２ A diffusion plate for diffusing bubbles containing gas; The CO ２ a second outlet for discharging the amine solution in which gas-containing bubbles have been sufficiently diffused to the outside; Equipped with The third tank is The CO ２ a tank to which an amine solution in which gas-containing bubbles have been sufficiently diffused is supplied through the first pipe; and The third tank is a chloride salt supplying means for supplying a chloride salt solution or a chloride salt powder into the third tank; The CO ２ a stirring blade for stirring the mixed solution of the chloride salt solution or the chloride salt powder after supplying the chloride salt solution or the chloride salt powder to an amine solution in which bubbles containing gas have been sufficiently diffused; a cone-shaped enrichment section whose horizontal cross-sectional area gradually decreases toward a lower end of the third tank; A rake that rotates in the enrichment section along the inclination of the enrichment section; a third outlet provided at a lower portion of the rake for discharging carbonate that is converted by the supply of the chloride salt solution or the chloride salt powder and deposited in the thickening section to the outside; CO ２ Separation, recovery and conversion equipment.

3. 2. The CO purifying apparatus according to claim 1, wherein the amine solution supplying means comprises: a first storage tank for storing the amine solution; a second pipe connecting the first storage tank and the first tank; and a pump provided on the second pipe. ２ Separation, recovery and conversion equipment.

4. 3. The CO purifying apparatus according to claim 2, wherein the amine solution supplying means comprises: a first storage tank for storing the amine solution; a second pipe connecting the first storage tank and the second tank; and a pump provided on the second pipe. ２ Separation, recovery and conversion equipment.

5. The CO2 extracting method according to claim 1, characterized in that the chloride salt supplying means comprises: a second storage tank for storing the chloride salt solution or the chloride salt powder; a third pipe connecting the second storage tank and the first tank; and a pump provided on the third pipe. ２ Separation, recovery and conversion equipment.

6. The CO2 extracting method according to claim 2, characterized in that the chloride salt supplying means comprises: a second storage tank for storing the chloride salt solution or the chloride salt powder; a third pipe connecting the second storage tank and the third tank; and a pump provided on the third pipe. ２ Separation, recovery and conversion equipment.

7. A liquid delivery mechanism is provided for delivering the amine solution recovered at the third outlet to the amine solution supply means.

3. The CO according to claim 2 . ２ Separation, recovery and conversion equipment.

8. The first CO ２ A second CO ２ Equipped with a concentration meter, The first CO ２ CO concentration meter ２ Concentration and the second CO ２ CO concentration meter ２ The CO2 absorbed in the amine solution is calculated based on the concentration of ２ and the moles of the tertiary amine in the amine solution. ２ The CO by the diffuser plate under the condition of loading of 0.4 to 0.6 ２ The diffusion of gas-containing bubbles is stopped, and the chloride salt solution or the chloride salt powder is supplied by the chloride salt supply means. The CO according to claim 1 or 2, ２ Separation, recovery and conversion equipment.

9. 2. The CO purifier according to claim 1, wherein the first outlet is connected to a seventh pipe equipped with a pump. ２ Separation, recovery and conversion equipment.

10. 3. The CO purifier according to claim 2, wherein the third outlet is connected to an eighth pipe equipped with a pump. ２ Separation, recovery and conversion equipment.

11. 2. The CO 2 storage tank according to claim 1, wherein the first tank is provided with at least one of a manometer and a level gauge. ２ Separation, recovery and conversion equipment.

12. 3. The CO 2 storage tank according to claim 2, wherein the second tank is provided with at least one of a manometer and a level gauge. ２ Separation, recovery and conversion equipment.

13. The CO ２ The CO2 analyzer according to claim 11 or 12, characterized in that before the gas-containing bubbles are diffused, the liquid level of the amine solution is measured by the manometer or the liquid level gauge, and if the liquid level is lower than a specified value, water or the amine solution is replenished. ２ Separation, recovery and conversion equipment.

14. A liquid sampling means for sampling the mixed solution is provided, a density meter for measuring the density of the mixed solution, a weight meter for measuring the weight of the mixed solution, a viscometer for measuring the viscosity of the mixed solution, and an electrical conductivity meter for measuring the electrical conductivity of the mixed solution, After measuring these physical properties, a returning means is provided for returning the sampled mixed solution to the collection destination. The CO according to claim 1 or 2, ２ Separation, recovery and conversion equipment.

15. The CO 2 solution according to claim 1 or 2, wherein the concentration of the tertiary amine in the amine solution is 10 to 40 mass %. ２ Separation, recovery and conversion equipment.

16. The first tanks are provided in multiple stages in series or multiple stages in parallel, The exhaust port of the first tank in the front stage and the air diffuser plate of the first tank in the rear stage are connected by a fourth pipe.

2. The CO according to claim 1 , ２ Separation, recovery and conversion equipment.

17. The second tanks are provided in multiple stages in series or multiple stages in parallel, The exhaust port of the second tank in the front stage and the air diffuser plate of the second tank in the rear stage are connected by a fifth pipe.

3. The CO according to claim 2 . ２ Separation, recovery and conversion equipment.

18. The CO according to claim 1 or 2 ２ CO using separation, recovery and conversion equipment ２ This is a separation, recovery and conversion method, an amine solution supplying step of supplying the amine solution into a tank; Into the amine solution, CO is introduced from the air diffuser. ２ a diffusing step of diffusing gas-containing bubbles; The CO ２ a chloride salt supplying step of supplying the chloride salt solution or the chloride salt powder to an amine solution in which gas-containing bubbles have been sufficiently diffused; The CO ２ a stirring step of stirring a mixed solution of the amine solution in which gas-containing bubbles have been sufficiently diffused and the chloride salt solution or the chloride salt powder with a stirring blade; a discharge step of concentrating the carbonate converted in the mixed solution by supplying the chloride salt solution or the chloride salt powder in the concentrating section and then discharging the carbonate to the outside of the apparatus; CO ２ Separation, recovery and conversion method.

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