Carbon dioxide fixation device, carbon dioxide fixation method, and manufacturing method of concrete

Abstract

To provide a carbon dioxide fixation device capable of cutting down maintenance trouble and accelerating a fixation rate of carbon dioxide.SOLUTION: The disclosure relates to a device which is a carbon dioxide fixation device comprising a container that stores a carbon dioxide fixation liquid and a carbon dioxide supply section for supplying carbon dioxide to the container. The container includes a container body and a lid part, the container body having an opening part, and the lid part being attached to the container body to seal the opening part airtightly. The container is configured to enable, by autorotation of the container, a liquid phase part made of the carbon dioxide fixation liquid and a gas phase part including the carbon dioxide to be mixed, and an opening end of the carbon dioxide supply section in the container is disposed in the gas phase part.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a carbon dioxide fixation device, a carbon dioxide fixation method, and a concrete manufacturing method. [Background technology]

[0002] In Patent Document 1, carbon dioxide gas (CO2) is immobilized in the cement hydrate by blowing the carbon dioxide gas into a mixture of cement hydrate and water. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2022-156516 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the method of Patent Document 1, carbon dioxide gas is injected into a mixture of cement hydrate and water, so the carbon dioxide gas supply port is prone to clogging and maintenance is time-consuming. In addition, the carbon dioxide gas fixation rate in the method of Patent Document 1 is not sufficient, and there is a demand for an increased carbon dioxide gas fixation rate.

[0005] The present invention has been made in consideration of the above circumstances, and provides a carbon dioxide fixation device that requires less maintenance and can increase the fixation rate of carbon dioxide. [Means for solving the problem]

[0006] According to the present invention, the following inventions are provided. [1] A carbon dioxide fixation device comprising a container for accommodating a carbon dioxide fixation liquid and a carbon dioxide supply unit for supplying carbon dioxide into the container, the container comprising a container body and a lid, the container body having an opening, the lid being attached to the container body so as to airtightly close the opening, the container being configured so that a liquid phase portion consisting of the carbon dioxide fixation liquid and a gas phase portion containing the carbon dioxide can be mixed by the rotation of the container, and the opening end of the carbon dioxide supply unit within the container is disposed in the gas phase portion. [2] The device described in [1], further comprising an external communication part that connects the inside and outside of the container, the external communication part comprising a measuring means capable of measuring the flow rate and / or wind direction of carbon dioxide gas. [3] The apparatus described in [1] or [2], wherein the lid portion is provided with a rotary joint composed of a rotating portion and a fixed portion, and the carbon dioxide gas supply portion and the external communication portion are each connected to the fixed portion. [4] The device described in [1] or [2], wherein the container body has a flange portion located away from the opening end of the opening, and the opening is airtightly sealed by the lid portion being in close contact with the flange portion. [5] A method for immobilizing carbon dioxide using the apparatus described in [2], comprising: a mixing step of mixing the carbon dioxide immobilization liquid and the carbon dioxide gas by rotating the container on its axis while the container contains the carbon dioxide immobilization liquid and the carbon dioxide gas; and a control step of controlling the flow rate of the carbon dioxide gas supplied to the gas phase section using the flow rate of the carbon dioxide gas obtained by the measuring means and / or the wind direction indicating the flow of gas in and out of the container. [6] The method according to [5], wherein, in the control step, when the carbon dioxide gas that has not been completely fixed is discharged through the external communication part, the carbon dioxide gas that has not been completely fixed is introduced into a storage part in which the carbon dioxide gas fixation liquid is stored. [7] The method according to [5] or [6], wherein the carbon dioxide gas fixing liquid contains cement. [8] A method for producing concrete using the method described in [5] or [6], wherein the liquid phase in which carbon dioxide is immobilized by the mixing step and the control step is used as part of the mixing water. Effect of the Invention

[0007] In the method of the present invention, since carbon dioxide gas can be supplied into the gas phase, clogging of the carbon dioxide gas supply port is unlikely to occur, and maintenance work is reduced. Moreover, as shown in the examples and comparative examples described later, the method of mixing a liquid phase part consisting of a carbon dioxide gas immobilizing liquid and a gas phase part containing carbon dioxide gas by rotating the container has a higher carbon dioxide gas fixation rate than stirring using a stirring blade. Therefore, according to the present invention, a carbon dioxide gas fixation device is provided that can reduce maintenance work and increase the carbon dioxide gas fixation rate. Moreover, in the device of the present invention, the opening of the container body is configured to be airtightly closed with a lid, making it easy to control the flow rate of carbon dioxide gas supplied into the container. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a perspective view of a carbon dioxide fixation device 10 according to one embodiment of the present invention. [Diagram 2] 2 is an enlarged view of the vicinity of the lid portion 5, showing a state in which the lid portion 5 has been separated from the container body 4 from the state shown in FIG. [Diagram 3] 3 is an enlarged view of the cover 5, rotary joint 9, and various pipes extracted from FIG. 2. [Figure 4] 4 is a perspective view of FIG. 3 as seen from below the lid portion 5. FIG. [Diagram 5] FIG. 2 is a perspective view showing a modified example of the carbon dioxide gas fixation device 10 in FIG. [Figure 6] FIG. 2 is an explanatory diagram for explaining a method for producing concrete according to one embodiment of the present invention. [Figure 7] 1 is a graph showing the change over time in the carbon dioxide fixation rate in Example 1 and Comparative Example 1. [Figure 8] 1 is a graph showing the relationship between the carbon dioxide gas concentration in a container 1 and the carbon dioxide gas fixation rate in Example 1 and Comparative Example 1. [Figure 9] 13 is a graph showing the relationship in Test 2 between the carbon dioxide gas concentration in the container 1 and the carbon dioxide gas supply rate at which the amount of gas flowing in and out through the external communication pipe 3a is minimized. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, embodiments of the present invention will be described. Various features shown in the following embodiments can be combined with each other. Also, each feature can be an invention independently.

[0010] 1. Carbon dioxide fixation device 10 A carbon dioxide fixation device 10 according to one embodiment of the present invention will be described with reference to Figures 1 to 4. As shown in Figure 1, the carbon dioxide fixation device 10 includes a container 1 that contains a carbon dioxide fixation liquid, a carbon dioxide supplying section 2 for supplying carbon dioxide into the container 1, an external communication section 3 that communicates the inside and outside of the container 1, and a carbon dioxide concentration measuring section 8 that measures the carbon dioxide concentration in the container 1. The external communication section 3 and the carbon dioxide concentration measuring section 8 can each be omitted if not required.

[0011] The carbon dioxide gas immobilizing liquid is a liquid containing an immobilizing component capable of immobilizing carbon dioxide gas. One example of the carbon dioxide gas immobilizing liquid is an alkaline aqueous solution, in which case carbon dioxide gas can be immobilized by a neutralization reaction between the alkaline aqueous solution and carbon dioxide gas. The immobilization of carbon dioxide gas is preferably carried out by generating a carbonate by a reaction between the immobilizing component and carbon dioxide gas. When the carbonate is poorly soluble in water, such as calcium carbonate, the carbonate can be precipitated.

[0012] The carbon dioxide fixation liquid is, for example, a cement-containing liquid that contains cement. The cement preferably contains Portland cement. The Portland cement is, for example, ordinary Portland cement, and contains calcium silicates such as tricalcium silicate (abbreviated as alite, with a composition of 3CaO·SiO2) and dicalcium silicate (abbreviated as belite, with a composition of 2CaO·SiO2). Calcium carbonate is produced by the reaction of calcium silicate hydrate with carbon dioxide.

[0013] Cement-containing liquid can be obtained by mixing cement and water to disperse the cement in the water, or by dissolving the washing water generated during the process of cleaning ready-mix concrete production equipment or return concrete (remaining ready-mix concrete from the construction site and returned to the ready-mix concrete plant) in water and classifying it to remove gravel and sand. The cement-containing liquid obtained from washing water or return concrete is generally called sludge water. The supernatant liquid of sludge water does not contain cement, but it is defined as a cement-containing liquid because it contains dissolved components derived from cement. Sludge water can be used to manufacture ready-mix concrete by carrying out the necessary treatment. In either case, carbon dioxide can be immobilized by reacting it with cement or dissolved components derived from cement. In addition, concrete can be strengthened by precipitating calcium carbonate.

[0014] The container 1 is configured to be rotatable, and by rotating the container 1 while the carbon dioxide gas immobilizing liquid and carbon dioxide gas are contained in the container 1, the liquid phase part 1c consisting of the carbon dioxide gas immobilizing liquid and the gas phase part 1d containing carbon dioxide gas can be mixed to immobilize the carbon dioxide gas in the carbon dioxide gas immobilizing liquid. According to this method, the fixation rate of the carbon dioxide gas can be increased compared to a method in which the carbon dioxide gas is blown into the carbon dioxide gas immobilizing liquid while stirring the carbon dioxide gas immobilizing liquid. In addition, since it is not necessary to provide a carbon dioxide gas supply port in the carbon dioxide gas immobilizing liquid, clogging of the supply port by solids contained in the carbon dioxide gas immobilizing liquid is suppressed, and the maintenance work can be reduced.

[0015] The container 1 is preferably configured to rotate about a rotation axis 1a. The drive mechanism 7 for rotating the container 1 is preferably configured by one or both of a motor 7a that rotates the rotation axis 1a and a roller 7b that rotates the container 1 while supporting the side surface of the container 1, thereby rotating the container 1.

[0016] Preferably, a rotating member 1b is provided in the container 1, which rotates about a rotation axis 1a as the container 1 rotates. The rotation of the rotating member 1b as the container 1 rotates promotes mixing of the carbon dioxide fixation liquid and the carbon dioxide. The rotating member 1b is, for example, a blade 1b1 extending in a direction not perpendicular to the rotation axis 1a. The carbon dioxide fixation liquid is scooped up by the blade 1b1, and then the carbon dioxide fixation liquid falls by gravity. This process is repeated, whereby the carbon dioxide fixation liquid and the carbon dioxide are efficiently mixed. The blade 1b1 is preferably provided so as to protrude from the bottom or side of the container 1.

[0017] In one example, the blade 1b1 is provided in a spiral shape. In this case, the rotation of the blade 1b1 accompanying the rotation of the container 1 enables the transport of the carbon dioxide fixation liquid. Specifically, when the carbon dioxide fixation liquid is injected into the container 1, the container 1 is rotated in one direction to transport the carbon dioxide fixation liquid toward the bottom of the container 1, and when the carbon dioxide fixation liquid is discharged from the container 1, the container 1 is rotated in the other direction to transport the carbon dioxide fixation liquid toward the opening 4a of the container 1. In this case, it is possible to discharge the carbon dioxide fixation liquid from the container 1 without changing the inclination angle of the container 1, which is efficient. On the other hand, a tilting mechanism that allows the container 1 to be tilted may be provided, and the carbon dioxide fixation liquid in the container 1 may be discharged by tilting the container 1 with the tilting mechanism.

[0018] The rotating member 1b may be one that revolves around the rotating shaft 1a and rotates around another rotating shaft. In this case, the rotation of the rotating member 1b further promotes the mixing of the carbon dioxide gas immobilizing liquid and the carbon dioxide gas.

[0019] The carbon dioxide gas supply unit 2 is configured to be able to supply carbon dioxide gas into the container 1. An open end 2a4 of the carbon dioxide gas supply unit 2 in the container 1 is disposed in the gas phase portion 1d. As shown in FIG. 3, the carbon dioxide gas supply unit 2 preferably includes a carbon dioxide gas supply pipe 2a and a carbon dioxide gas supply source 2b. The carbon dioxide gas supply pipe 2a is a pipe having one end connected to the carbon dioxide gas supply source 2b and the other end disposed inside the container 1. Carbon dioxide gas released from the carbon dioxide gas supply source 2b is supplied into the container 1 through the carbon dioxide gas supply pipe 2a. The carbon dioxide gas supply source 2b is, for example, a carbon dioxide gas cylinder. The carbon dioxide gas in the carbon dioxide gas cylinder is preferably, for example, recovered carbon dioxide gas generated in a facility (factory or power plant) that generates carbon dioxide gas. By using such carbon dioxide gas, it is possible to reduce the amount of carbon dioxide gas emitted into the atmosphere.

[0020] The carbon dioxide gas supply unit 2 preferably includes a gas flow meter 2c capable of measuring the flow rate of carbon dioxide gas flowing through the carbon dioxide gas supply pipe 2a. In this case, it becomes easy to adjust the supply speed of carbon dioxide gas and to grasp the supply amount.

[0021] The external communication part 3 is configured to communicate the inside and outside of the container 1. By providing the external communication part 3, it is possible to prevent the inside of the container 1 from being depressurized or pressurized, and to suppress deformation of the container 1 due to depressurization or pressurization. The external communication part 3 preferably includes an external communication pipe 3a. The external communication pipe 3a is a pipe having one end disposed inside the container 1 and the other end disposed outside the container 1. The external communication part 3 may be constituted by an opening provided in the container 1, instead of providing the external communication pipe 3a.

[0022] The external communication part 3 is preferably provided with a measuring means 3b capable of measuring the flow rate and / or wind direction of carbon dioxide gas. By grasping the flow rate and / or wind direction of carbon dioxide gas flowing through the external communication part 3, it is possible to determine whether the flow rate of carbon dioxide gas supplied to the container 1 is appropriate. The measuring means 3b may be capable of measuring only the exhaust flow rate through the external communication part 3, or may be capable of measuring only the intake flow rate, but it is preferable that the measuring means 3b is capable of measuring both the exhaust flow rate and the intake flow rate. The measuring means 3b may be configured as a single device capable of measuring both the exhaust flow rate and the intake flow rate, and may be configured as a first measuring means 3b1 for measuring the exhaust flow rate and a second measuring means 3b2 for measuring the intake flow rate.

[0023] The carbon dioxide concentration measuring unit 8 is configured to be able to measure the carbon dioxide concentration in the container 1. The carbon dioxide concentration measuring unit 8 preferably includes a carbon dioxide concentration measuring tube 8a, and can measure the carbon dioxide concentration in the container 1 by detecting the carbon dioxide taken out of the container 1 through the carbon dioxide concentration measuring tube 8a with a carbon dioxide detection unit 8b disposed outside the container 1. Measuring the carbon dioxide concentration in the container 1 makes it easier to measure the fixation rate of the carbon dioxide and adjust the carbon dioxide supply rate.

[0024] The container 1 preferably includes a container body 4 and a lid 5. The carbon dioxide fixation liquid is contained in the container body 4. As shown in FIG. 2, the container body 4 has an opening 4a. The lid 5 is attached to the container body 4 so as to airtightly close the opening 4a. By airtightly closing the opening 4a with the lid 5, it becomes possible to accurately measure the flow rate of carbon dioxide gas in the container 1 flowing out through the external communication part 3. This makes it possible to suppress unnecessary outflow of carbon dioxide gas and to accurately calculate the amount of carbon dioxide gas fixed. In addition, in the device of this embodiment, the carbon dioxide fixation liquid is introduced and removed through one opening 4a, so that airtightness can be increased by simply closing only one opening 4a with the lid 5.

[0025] As shown in FIG. 2, the container body 4 preferably has a flange portion 4c at a position away from the opening end 4b of the opening 4a, and the opening 4a is airtightly closed by the lid portion 5 being in close contact with the flange portion 4c. The opening 4a can be airtightly closed by bringing the lid portion 5 into close contact with the opening end 4b, but if the carbon dioxide fixation liquid contains solids, the solids are likely to adhere to the opening end 4b when the contents are taken out of the container body 4, and if the solids are caught between the lid portion 5 and the opening end 4b, the airtightness may decrease. On the other hand, since the flange portion 4c is located away from the opening end 4b, the solids in the carbon dioxide fixation liquid are unlikely to adhere to the flange portion 4c, and the decrease in airtightness is suppressed. This configuration is not limited to containers for carbon dioxide fixation devices, but can be applied to any container that requires airtightness.

[0026] The flange portion 4c preferably includes a seal member 4c1 made of an elastic material such as rubber at a portion facing the open end 5a1 of the lid portion 5. The seal member 4c1 is preferably annular. In this case, the lid portion 5 (more specifically, the open end 5a1 of the tubular portion 5a) is pressed against the seal member 4c1 to improve airtightness. The lid portion 5 preferably includes a tubular portion 5a and an upper wall portion 5b. The upper wall portion 5b is provided so as to close one end of the tubular portion 5a.

[0027] The lid portion 5 is preferably configured to be opened and closed by a drive mechanism 6. The drive mechanism 6 is, for example, a cylinder mechanism 6a. The cylinder mechanism 6a preferably includes a cylinder 6a1 and a piston rod 6a2, the cylinder 6a1 being fixed to the container body 4, and the piston rod 6a2 being fixed to the lid portion 5. In this case, the lid portion 5 can be opened and closed by changing the amount of protrusion of the piston rod 6a2. Also, the lid portion 5 can be pressed against the flange portion 4c by a force in a direction that reduces the amount of protrusion of the piston rod 6a2. The cylinder 6a1 can be fixed to a cylinder fixing portion 4d provided on the container body 4. Note that the cylinder 6a1 may be fixed to a portion other than the container body 4, and the piston rod 6a2 may be fixed to a portion other than the lid portion 5. In one example, as in the modified example shown in FIG. 5, the piston rod 6a2 may be fixed to the rotary joint 9. Also, the cylinder 6a1 may be disposed on the opposite side of the rotary joint 9 from the lid portion 5. In this case, the cylinder 6a1 can be fixed to any fixing point. In this case, there is an advantage that the cylinder mechanism 6a does not rotate even if the container body 4 rotates. Even with this configuration, the lid part 5 can be opened and closed by changing the protruding amount of the piston rod 6a2. Specifically, the lid part 5 can be opened by reducing the protruding amount of the piston rod 6a2, and the lid part 5 can be pressed against the container body 4 (preferably the flange part 4c) by increasing the protruding amount of the piston rod 6a2.

[0028] 3 and 4, the carbon dioxide gas supply pipe 2a, the external communication pipe 3a, and the carbon dioxide gas concentration measuring pipe 8a are preferably provided so as to penetrate the lid 5 (preferably the upper wall 5b). The carbon dioxide gas supply pipe 2a is disposed at a position where the open end 2a4 inside the container 1 is farther from the upper wall 5b of the lid 5 (in other words, closer to the bottom of the container body 4) than the open end 3a4 inside the container 1 of the external communication pipe 3a. This prevents the carbon dioxide gas supplied from the carbon dioxide gas supply pipe 2a from being discharged through the external communication pipe 3a before being immobilized in the carbon dioxide gas immobilization liquid.

[0029] In addition, the lid 5 is preferably provided with a rotary joint 9 consisting of a rotating part 9a and a fixed part 9b. The rotating part 9a and the fixed part 9b are capable of rotating relative to each other. The rotating part 9a is fixed to the lid 5. The carbon dioxide gas supply source 2b, the external communication pipe 3a, and the carbon dioxide gas concentration measurement pipe 8a are each fixed to the fixed part 9b. The carbon dioxide gas supply source 2b, the external communication pipe 3a, and the carbon dioxide gas concentration measurement pipe 8a are each connected to the inside of the container 1 through the rotary joint 9. In other words, the carbon dioxide gas supply source 2b, the external communication pipe 3a, and the carbon dioxide gas concentration measurement pipe 8a are divided into rotating parts 2a1, 3a1, and 8a1 and fixed parts 2a2, 3a2, and 8a2 by the rotary joint 9 provided on the lid 5.

[0030] One end of each of the rotating parts 2a1, 3a1, and 8a1 of the pipes is connected to the rotating part 9a of the rotary joint 9, and the other end of each of the rotating parts 2a1, 3a1, and 8a1 of the pipes is connected to the fixed part 9b of the rotary joint 9. The rotating parts 2a1, 3a1, and 8a1 of the pipes and the fixed parts 2a2, 3a2, and 8a2 of the pipes are electrically connected to each other through the flow paths 2a3, 3a3, and 8a3 provided in the rotary joint 9. Therefore, even if the rotating part 9a and the fixed part 9b rotate relatively, the electrical connection between the rotating parts 2a1, 3a1, and 8a1 of the pipes and the fixed parts 2a2, 3a2, and 8a2 is maintained. The other end of the fixed part 2a2 of the carbon dioxide gas supply source 2b is connected to the carbon dioxide gas supply source 2b. The other end of the fixed part 3a2 of the external communication pipe 3a is connected to a storage part (e.g., a water tank 23 (shown in FIG. 6) or a tank) that stores a carbon dioxide fixing liquid. The other end of the fixed part 8a2 of the carbon dioxide concentration measurement pipe 8a is connected to the carbon dioxide detection part 8b.

[0031] 2. Method for fixing carbon dioxide gas The carbon dioxide fixation method according to one embodiment of the present invention can be carried out by using the carbon dioxide fixation device 10 described above. This method includes a mixing step of mixing the carbon dioxide fixation liquid and the carbon dioxide gas by rotating the container 1 on its axis while the container contains the carbon dioxide fixation liquid and the carbon dioxide gas, and a control step of controlling the flow rate of the carbon dioxide gas supplied to the gas phase section 1d by using the flow rate of the carbon dioxide gas obtained by the measuring means 3b and / or the wind direction indicating the flow of gas in and out of the container 1. This step allows the carbon dioxide gas to be fixed in the carbon dioxide fixation liquid. Examples of the gas that flows in and out include gas that flows out of the container 1 (e.g., carbon dioxide gas) and gas that flows in to the container 1 (e.g., air, a mixture of air and carbon dioxide gas).

[0032] In the control step, the flow rate of the carbon dioxide gas is preferably controlled so that the flow rate of the carbon dioxide gas flowing through the external communication part 3 becomes zero. When the supply rate of the carbon dioxide gas is higher than the fixation rate of the carbon dioxide gas, the carbon dioxide gas that has not been fixed is discharged through the external communication part 3. In this case, the discharge of the carbon dioxide gas can be suppressed by lowering the supply rate of the carbon dioxide gas. On the other hand, when the supply rate of the carbon dioxide gas is lower than the fixation rate of the carbon dioxide gas, the inside of the container 1 is in a decompressed state and the outside air is introduced into the container 1 through the external communication part 3. In this case, the fixation rate of the carbon dioxide gas can be increased by increasing the supply rate of the carbon dioxide gas. Therefore, by controlling the supply rate of the carbon dioxide gas so that the flow rate of the carbon dioxide gas flowing through the external communication part 3 becomes zero, it becomes possible to efficiently fix the carbon dioxide gas while suppressing the discharge of the carbon dioxide gas to the outside.

[0033] In the control step, when the carbon dioxide gas that has not been completely fixed is discharged through the external communication part 3, the carbon dioxide gas that has not been completely fixed can be introduced into a storage part storing a carbon dioxide gas immobilizing liquid and immobilized in the carbon dioxide gas immobilizing liquid. In this case, by using a sufficient amount of carbon dioxide gas immobilizing liquid for the amount of carbon dioxide gas that has not been completely fixed, it becomes possible to collect the carbon dioxide gas without releasing it into the atmosphere.

[0034] 3. Concrete manufacturing method The method for producing concrete according to the present invention will be described with reference to Fig. 6, using water in which cement, which is a cement-containing liquid, is dispersed as an example of a carbon dioxide fixing liquid. Here, the cement-dispersed water 20 refers to sludge water, water mixed with cement, etc.

[0035] 6, the cement-dispersed water 20b before carbon dioxide gas is immobilized is stored in a water tank 23, and the cement-dispersed water 20b in the water tank 23 is transferred to the carbon dioxide gas immobilization device 10, where carbon dioxide gas is supplied to immobilize the carbon dioxide gas. The external communication pipe 3a is connected to the water tank 23, and is configured to supply the carbon dioxide gas that has not been immobilized to the water tank 23 and recover it.

[0036] In the present invention, the cement-dispersed water 20 (an example of the "liquid phase") into which carbon dioxide gas has been supplied and immobilized by the above-mentioned mixing step and control step is used as part of the mixing water during concrete production. In the process of using the cement-dispersed water as mixing water, the cement contained in addition to water and the immobilized carbon dioxide gas can be used as concrete materials. In this embodiment, the cement-dispersed water 20 to which carbon dioxide gas has been supplied is stored in the cement-dispersed water tank 15, and a required amount is supplied to the mixer 12, but the cement-dispersed water 20 to which carbon dioxide gas has been supplied may be directly supplied to the mixer 12 from the carbon dioxide gas immobilization device 10.

[0037] In Fig. 6, one carbon dioxide fixation device 10 is used, but two or more are preferable, and in practice, the number is determined based on the production capacity of the mixer 12 of the batcher plant 11. For example, the mixer 12 of the batcher plant 11 is usually operated in batch processing, and the mixing volume of one batch is 2.3 m 3 When a mixer 12 operates at 60 to 75 batches per hour, it generally requires 1 m 3 When making concrete, about 170L of water is used, so the amount of mixing water required per hour is 20 to 30m 3 It becomes.

[0038] In the present invention, the carbon dioxide fixation apparatus 10 is operated in batches, and the time required for fixation of carbon dioxide per batch is 20 minutes or more. Therefore, the capacity of the cement-dispersed water 20 is set to 5 m 3 When using the carbon dioxide fixation device 10, the maximum amount that can be processed by one unit is 15 m per hour. 3 Therefore, under such conditions, two or more carbon dioxide fixation devices 10 should be installed.

[0039] The cement-dispersed water 20 to which carbon dioxide has been supplied by the carbon dioxide fixation apparatus 10 is fed into the chute 16 and transferred to the cement-dispersed water tank 15 by a pump. When the number of carbon dioxide fixation apparatuses 10 installed increases, the chute 16 can be expanded appropriately. In the present invention, the cement-dispersed water tank 15 is installed to adjust the difference in processing capacity between the carbon dioxide fixation apparatus 10 and the mixer 12, thereby enabling smooth concrete production in the batcher plant 11. The cement-dispersed water tank 15 is equipped with an agitator 17 to prevent cement from settling.

[0040] In addition, a buffer tank 19 is provided in the batcher plant 11, and the cement dispersion water 20 is circulated between the buffer tank 19 and the cement dispersion water tank 15 using a pump, and when a concrete production signal is received, it is transferred from the buffer tank 19 to the mixing water meter 13. By circulating the cement dispersion water 20 between the buffer tank 19 and the cement dispersion water tank 15, the occurrence and growth of scale (adherent matter) in the piping that transfers the cement dispersion water 20 is suppressed. Furthermore, by transferring the cement dispersion water 20 from the buffer tank 19 to the mixing water meter 13, the mixing water to be put into the mixer 12 can be measured in a short time without relying on the pump capacity. The amount of water measured for the cement dispersion water 20 that has entered the mixing water meter 13 is calculated from the cement solids concentration obtained by the cement dispersion water concentration meter 18, and fresh water 21 is added appropriately so that the amount of water for the specified concrete mix is ​​reached.

[0041] The measured amount of the cement dispersion water 20 is mixed with the amount of mixed cement minus the amount of cement contained therein, and aggregate in a mixer 12, whereby concrete containing carbon dioxide gas can be easily produced. EXAMPLES

[0042] 1. Test 1: Verification test of the difference in carbon dioxide fixation rate due to different stirring methods <Summary> In Test 1, a test was conducted to verify the difference in the carbon dioxide fixation rate due to differences in the stirring method.

[0043] <Preparation of simulated sludge water> First, 3.53 kg of ordinary Portland cement and 20 L (kg) of water were mixed and stirred to create a sample with a concentration of 15 mass%. This sample has a composition close to that of sludge water, and is hereafter referred to as "simulated sludge water."

[0044] <Example 1> In Example 1, simulated sludge water was poured into a container body 4 provided in an electric concrete mixer Mazeta (manufactured by Aluminis, model AMZ-30Y, container volume 63 L), which is a pod mixer, and then a lid 5 for sealing an opening 4a was attached to configure the container 1. A rotary joint 9 (manufactured by CKD, model: RJF-6A-04) was fixed to the lid 5.

[0045] As shown in Fig. 3, the carbon dioxide gas supply pipe 2a, the external communication pipe 3a, and the carbon dioxide gas concentration measurement pipe 8a were connected to the rotary joint 9 so as to be divided by the rotary joint 9. The carbon dioxide gas supply pipe 2a was positioned so that the open end 2a4 inside the container 1 was not immersed in the simulated sludge water. The external communication pipe 3a was designed to allow gas to freely enter and exit, and carbon dioxide gas was introduced through the carbon dioxide gas supply pipe 2a until the carbon dioxide gas concentration inside the container 1 reached 80% by volume, after which the introduction of carbon dioxide gas was stopped.

[0046] Next, the vessel 1 was rotated at 30 rpm to mix the simulated sludge water with carbon dioxide gas, while measuring the change over time in the carbon dioxide gas concentration in the vessel 1.

[0047] <Comparative Example 1> In Comparative Example 1, simulated sludge water prepared in the same manner as in Example 1 was poured into a 40 L capacity container body 4, and then a lid 5 for sealing an opening 4a was attached to construct a container 1. A carbon dioxide gas supply pipe 2a, an external communication pipe 3a, and a carbon dioxide gas concentration measuring pipe 8a were fixed to the lid 5, and an agitator (Tokyo Rikakikai, model: ZZ-1200) equipped with an agitating blade (As One, TUT-125) was also fixed thereto.

[0048] The carbon dioxide gas supply pipe 2a was positioned so that the open end inside the vessel 1 would not be submerged in the simulated sludge water. The external communication pipe 3a was designed to allow gas to freely enter and exit, and carbon dioxide gas was supplied through the carbon dioxide gas supply pipe 2a until the carbon dioxide gas concentration inside the vessel 1 reached 80% by volume, after which the supply of carbon dioxide gas was stopped.

[0049] Next, the simulated sludge water and carbon dioxide gas were mixed by rotating the stirrer at 450 rpm, while the change over time in the carbon dioxide gas concentration in the vessel 1 was measured.

[0050] <Comparison between Example 1 and Comparative Example 1> FIG. 7 shows the results of converting the change over time in the carbon dioxide gas concentration in the vessel 1 measured in Example 1 and Comparative Example 1 into the fixation speed of carbon dioxide gas. As shown in FIG. 7, the fixation speed of carbon dioxide gas in Example 1 was higher than that in Comparative Example 1. Furthermore, FIG. 8 shows a plot of the relationship between the carbon dioxide gas concentration in the vessel 1 and the fixation speed of carbon dioxide gas. As shown in FIG. 8, in both Example 1 and Comparative Example 1, the carbon dioxide gas concentration in the vessel 1 and the fixation speed of carbon dioxide gas showed a high correlation. Furthermore, the slopes of the graphs in Example 1 and Comparative Example 1 were 0.117 and 0.031, respectively. From this result, it was found that the rotating vessel in Example 1 fixed carbon dioxide gas at a speed about 3.8 times faster than the stirring vessel in Comparative Example 1.

[0051] 2. Test 2: Examination of the method for controlling the supply rate of carbon dioxide gas In Test 2, carbon dioxide gas was supplied until the carbon dioxide gas concentration in the container 1 reached various values ​​shown in Table 1, and then the supply of carbon dioxide gas was controlled so that the amount of gas flowing in and out through the external communication pipe 3a became zero, and the carbon dioxide gas supply rate was recorded when the gas flow rate became zero. The results are shown in Table 1 and Figure 9. The gas flow rate in Table 1 indicates that carbon dioxide gas is flowing out when it is a positive value. [Table 1]

[0052] As shown in Table 1, it was found that the gas inflow / outflow rate can be made extremely small by adjusting the carbon dioxide gas supply rate, regardless of whether the carbon dioxide gas concentration in the container in the initial state is set to any value between 10.0 and 90.0% by volume. It was also found that the higher the carbon dioxide gas concentration in the container in the initial state, the higher the carbon dioxide gas supply rate when the gas inflow / outflow rate is minimum. When the gas inflow / outflow rate is zero, the carbon dioxide gas supply rate matches the carbon dioxide gas fixation rate, so the above results show that by increasing the carbon dioxide gas concentration in the container in the initial state, it is possible to increase the carbon dioxide gas fixation rate without discharging carbon dioxide gas outside the system. [Explanation of symbols]

[0053] 1: Container 1c:Liquid phase part 1d: Gas phase part 2: Carbon dioxide gas supply section 2a4: Open end 3:External communication part 3b:Measurement means 4: Container body 4a: Opening 4b:Open end 4c: Flange part 5: Lid 9: Rotary joint 9a: Rotating part 9b:Fixed part 10: Carbon dioxide fixation device

Claims

1. A carbon dioxide fixation apparatus comprising a container for accommodating a carbon dioxide fixation liquid and a carbon dioxide supply unit for supplying carbon dioxide into the container, The container comprises a container body and a lid, The container body has an opening, the lid is attached to the container body so as to airtightly close the opening, The container is configured so that a liquid phase portion consisting of the carbon dioxide gas immobilizing liquid and a gas phase portion containing the carbon dioxide gas can be mixed by rotating the container, An apparatus, wherein an open end of the carbon dioxide gas supply section within the container is disposed in the gas phase section.

2. 2. The apparatus of claim 1, Further, an external communication part that communicates the inside and the outside of the container is provided, The external communication unit is equipped with a measuring means capable of measuring the flow rate and / or the direction of the carbon dioxide gas.

3. 3. The apparatus according to claim 1 or 2, The cover portion is provided with a rotary joint composed of a rotating portion and a fixed portion, The carbon dioxide gas supply unit and the external communication unit are each connected to the fixed unit.

4. 3. The apparatus according to claim 1 or 2, The container body includes a flange portion located away from an opening end of the opening, The opening is air-tightly sealed by the lid portion being in close contact with the flange portion.

5. A method for fixing carbon dioxide gas using the device according to claim 2, a mixing step of mixing the carbon dioxide gas fixing liquid and the carbon dioxide gas by rotating the container on its axis while the carbon dioxide gas fixing liquid and the carbon dioxide gas are contained in the container; a control step of controlling the flow rate of the carbon dioxide gas supplied to the gas phase section based on the flow rate of the carbon dioxide gas obtained by the measuring means and / or the wind direction indicating the flow of the gas in and out of the container; A method comprising:

6. 6. The method of claim 5, When the carbon dioxide gas that has not been completely fixed is discharged through the external communication part in the control step, the carbon dioxide gas that has not been completely fixed is introduced into a storage part that stores the carbon dioxide gas fixation liquid.

7. 7. The method of claim 5 or claim 6, The carbon dioxide fixation liquid comprises cement.

8. A method for producing concrete using the method according to claim 5 or 6, A method for producing concrete, wherein the liquid phase in which carbon dioxide gas is immobilized by the mixing step and the control step is used as part of the mixing water.

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