Carbonation curing system and carbonation curing method

Abstract

The purpose of the present invention is to provide a carbonation curing system and a carbonation curing method which are capable of improving the efficiency of reaction between CO2 gas and concrete. The carbonation curing system comprises: at least two carbonation curing parts; a gas flow part through which a CO2-containing gas flows between the carbonation curing parts; a CO2 gas supply port for supplying the CO2-containing gas; and a CO2 gas discharge port for discharging the CO2-containing gas that has decreased CO2 concentration. In the carbonation curing system and the carbonation curing method, the carbonation curing parts are each provided with concrete that differ from each other in the degree of progress of carbonation curing, and the CO2-containing gas is supplied along a flow path of the CO2-containing gas so as to flow from concrete having a higher degree of progress of carbonation curing to concrete having a lower degree thereof.

Description

Carbonation curing system and carbonation curing method

[0001] The present invention relates to a carbonation curing system and a carbonation curing method.

[0002] In order to curb global warming, it is important to reduce emissions of carbon dioxide, which is the main cause of global warming. In this regard, various manufacturing facilities have been proposed that produce concrete products that forcibly absorb or carbonate carbon dioxide during production.

[0003] For example, Patent Document 1 listed below describes a carbon dioxide curing system and method that includes a primary curing chamber and a secondary curing chamber for curing concrete products, and supplies carbon dioxide gas to the secondary curing chamber to perform carbon dioxide curing. Patent Document 2 also describes a carbonation curing system that uses a thermal power plant as a carbon dioxide gas supply source and exhaust gas emitted from the thermal power plant.

[0004] JP 2023-16659 A JP 2012-126623 A

[0005] The carbonation curing systems described in Patent Documents 1 and 2 perform carbonation curing in a curing tank, remove the concrete that has been carbonated, and place the next concrete in the curing tank, thereby performing carbonation curing sequentially. However, as the carbonation curing of concrete progresses, CO ２ In the latter half of the curing period, the reactivity with CO gas decreases. ２ The gas is not used much and is discharged, ２ There was a need for a system that would allow the gas and concrete to react more efficiently.

[0006] The present invention has been made in view of the above circumstances, and ２ The object of the present invention is to provide a carbonation curing system and a carbonation curing method that can improve the reaction efficiency between gas and concrete.

[0007] The present inventors have conducted extensive research to solve the above problems, and have discovered that a concrete curing system is provided with two or more carbonation curing sections, and that the progress of carbonation curing of concrete in the carbonation curing sections and the CO ２The inventors have found that the above-mentioned problems can be solved by controlling the flow path of the gas containing CO. The present invention has been completed based on the above findings. That is, the present invention is as follows: [1] A carbonation curing system used in the production of concrete, comprising at least two or more carbonation curing sections and a CO gas supply section provided between the carbonation curing sections. ２ a gas distribution unit for distributing a gas containing CO ２ Supplying gas containing CO ２ A gas supply port and CO from the system ２ Reduced CO concentration ２ CO ２ a gas outlet, ２ A gas supply port is provided in at least one of the carbonation curing sections, and the CO ２ The gas outlet is the CO ２ The carbonation curing section is provided in at least one carbonation curing section different from the carbonation curing section provided with the gas supply port, and concrete having a different degree of carbonation curing is provided in each of the carbonation curing sections, and the CO ２ A gas containing CO ２ [2] After the concrete that has completed carbonation curing is removed, the gas containing ２ [3] The carbonation curing system according to [1], wherein the concrete in the carbonation curing section downstream of a flow path of the gas containing CO is transported to the carbonation curing section upstream, and uncured concrete is placed in the carbonation curing section furthest downstream of the flow path. ２ gas supply port, and the CO ２ A gas outlet is provided, and the CO ２ gas supply port, and the CO ２ The gas outlet is ２ the carbonation curing unit that supplies a gas containing ２ Reduced CO concentration ２and a valve for changing the carbonation curing section from which the gas containing CO is discharged. After the concrete that has been carbonation cured is removed, uncured concrete is placed in the carbonation curing section that has been removed, and the valve is used to change the carbonation curing section from which the gas containing CO is discharged. ２ The supply of gas containing CO ２ a flow path for a gas containing CO ２ Reduced CO concentration ２ [4] A carbonation curing method for use in manufacturing concrete, comprising: at least two or more carbonation curing sections having concretes with different degrees of carbonation curing progress; ２ [5] A carbonation curing method, comprising: removing the concrete after carbonation curing from the carbonation curing section; ２ [6] The carbonation curing method according to [4], wherein concrete in the carbonation curing section downstream of a flow path of a gas containing CO is transported to the carbonation curing section upstream, and uncured concrete is placed in the carbonation curing section furthest downstream of the flow path. ２ The supply of gas containing CO ２ a gas flow path including the carbonation curing section downstream of the carbonation curing section where uncured concrete is installed, ２ Reduced CO concentration ２ The carbonation curing method according to [4], wherein the gas containing the above is discharged from the carbonation curing section in which uncured concrete is placed.

[0008] According to the present invention, CO ２ It is possible to provide a carbonation curing system and a carbonation curing method that can improve the reaction efficiency between gas and concrete.

[0009] Fig. 1 is a side view showing an outline of a carbonation curing system according to a first embodiment; Fig. 2 is a side view showing an outline of a modified carbonation curing system according to the first embodiment; Fig. 3 is a side view showing an outline of a carbonation curing system according to a second embodiment; Fig. 4 is a top view showing an outline of a modified carbonation curing system according to the second embodiment;

[0010] The carbonation curing system and carbonation curing method of the present invention will be described in detail below, but the present invention is not limited to these embodiments.

[0011] [Carbonation curing system] The carbonation curing system of the present invention is a carbonation curing system used in the production of concrete, and includes at least two or more carbonation curing sections, and a carbonation curing unit that is provided between each carbonation curing section, and a carbonation curing unit that is provided between the carbonation curing sections. ２ a gas distribution unit that distributes a gas containing CO ２ Supplying gas containing CO ２ Gas supply and CO from the system ２ Reduced CO concentration ２ CO ２ and a gas outlet, wherein the supply port is provided in at least one carbonation curing section, and the outlet is provided in at least one carbonation curing section different from the carbonation curing section in which the supply port is provided, and concrete having a different degree of carbonation curing progress is provided in each carbonation curing section, ２ A gas containing CO ２ This is a carbonation curing system that supplies gas containing the above along a flow path so that concrete with a high degree of carbonation curing progresses to concrete with a low degree of carbonation curing progress.

[0012] <First embodiment> Fig. 1 is a side view showing a schematic diagram of a carbonation curing system according to the first embodiment. As shown in Fig. 1, the carbonation curing system 10 according to the first embodiment includes a first carbonation curing tank 12a, a second carbonation curing tank 12b, and a third carbonation curing tank 12c (hereinafter collectively referred to as "carbonation curing tanks 12a, 12b, 12c"), which correspond to the carbonation curing sections of the present invention and perform carbonation curing of concrete. The first carbonation curing tank 12a supplies CO ２ Supplying gas containing CO２ The third carbonation curing tank 12c is equipped with a gas supply port 14, and receives CO from the carbonation curing system 10. ２ Reduced CO concentration ２ CO ２ A gas outlet 16 is provided. In addition, between the first carbonation curing tank 12a and the second carbonation curing tank 12b, and between the second carbonation curing tank 12b and the third carbonation curing tank 12c, CO 2 gas is discharged between the respective carbonation curing tanks. ２ In the present invention, the gas flow section 18 is provided to flow a gas containing CO ２ The "CO ２ Reduced CO concentration ２ The gas containing CO is ２ is almost completely absorbed and CO ２ This means that the gases that do not contain

[0013] CO ２ CO supplied from the gas supply port 14 ２ The gas containing CO ２ There are no particular limitations as long as the carbon dioxide contains CO produced by a known method. ２ Examples of such exhaust gases include gases consisting only of carbon dioxide, carbon monoxide, and the like; exhaust gases from thermal power plants using coal, heavy oil, natural gas, etc. as fuel; exhaust gases from steel mills; exhaust gases from concrete factories; and exhaust gases from chemical plants. These may be used alone or in combination of two or more. Among these, various types of exhaust gases are preferred for their energy-saving and CO2-reducing properties in terms of reducing environmental impact. ２ It is preferable to use it because it is required to fix CO. ２ It may also be a gas with an increased concentration of CO (for example, carbon dioxide recovered from boiler exhaust gas and compressed in a gas cylinder). ２ The gas supply port 14 is ２ When using exhaust gas from each of the above facilities as a gas containing CO, a gas containing CO is branched off from a flue that connects the exhaust gas outlet of each facility to a chimney. ２ By connecting to the gas supply port 14, CO ２ In addition, a gas cylinder can be connected to the exhaust gas containing CO.２ A gas containing

[0014] In addition, CO ２ The gas containing CO ２ It may contain gases other than CO. ２ The gas other than CO is not particularly limited, and examples thereof include nitrogen, oxygen, water vapor, carbon monoxide, hydrogen sulfide, carbonyl sulfide, sulfur dioxide, nitrogen dioxide, methane, and hydrogen. ２ CO in gas containing ２ The concentration of CO is not particularly limited, but is preferably 1% by volume or more, and more preferably 5% by volume or more, from the viewpoint of efficiently performing carbonation curing of concrete and producing concrete. ２ from gas containing CO ２ to concentrate the preferred CO ２ The concentration may be set to .

[0015] CO ２ Supplying gas containing CO ２ The gas supply port 14 and the carbonation curing tanks 12b and 12c are supplied with CO ２ The supply ports 18a, 18a of the gas flow unit 18 for supplying the gas containing CO are preferably provided below the carbonation curing tanks 12a, 12b, 12c. ２ CO ２ CO is discharged from the gas outlet 16 and the carbonation curing tanks 12a and 12b. ２ The outlets 18b, 18b of the gas flow section 18 that discharge gas containing CO ２ It is preferable that the CO 2 supply port 14 is provided above the gas supply ports 18a, 18a of the gas circulation unit 18, and above the carbonation curing tanks 12a, 12b, 12c. ２ The gas containing CO ２ When the concentration of CO decreases, the specific gravity also decreases. ２ The gas with a reduced concentration of CO is likely to move to the upper side of the carbonation curing tanks 12a, 12b, and 12c. ２ The gas with a low concentration of CO is easily discharged. ２ Since gases with high concentrations of CO tend to remain in the carbonation curing tanks 12a, 12b, and 12c,２ It is possible to efficiently react gases containing

[0016] In addition, CO emitted from the carbonation curing system 10 ２ The gas containing CO is supplied to the third carbonation curing section 12c. ２ The CO is discharged from the gas outlet 16. ２ The gas containing CO ２ If it contains harmful substances other than CO ２ The gas can be sent from the gas outlet 16 to a harmful substance removal means (not shown) to remove harmful substances before being discharged outside the carbonation curing system 10.

[0017] The carbonation curing tanks 12a, 12b, and 12c are provided with concrete 22a, 22b, and 22c, respectively, which are at different stages of carbonation curing. The concrete 22a, 22b, and 22c are provided with CO ２ The carbonation curing tanks 12a and 12c are arranged along the flow path of the gas containing CO from the concrete 22a with a high degree of carbonation curing to the concrete 22c with a low degree of carbonation curing. ２ The first carbonation curing tank 12a is provided with concrete 22a having the highest degree of carbonation curing, followed by the second carbonation curing tank 12b, the third carbonation curing tank 12c, and the concretes 22b and 22c having the lowest degree of carbonation curing, respectively.

[0018] The degree of progress of carbonation curing is determined by the CO ２ Gas supply port 14, gas flow section 18 and CO ２ A sensor is provided at the gas outlet 16 to measure CO ２ CO concentration, gas flow rate, temperature and pressure are monitored. ２ The carbonation rate can be evaluated from the amount of CO consumed, or by monitoring the mass of concrete, which increases with the progress of carbonation. For example, the amount of CO entering one carbonation curing tank within a certain time Δt (s) can be evaluated from the amount of CO consumed. ２ CO flowing through the gas supply port 14 or the gas flow section 18 ２ CO of gas containing２ Concentration C １ (vol%) and gas flow rate F １ (m ３ / s) and pressure P １ (Pa) and temperature T １ (K) and CO ２ The molar mass m (kg / mol) and gas constant R = 8.31 (J / mol K) of CO flowing into the carbonation curing tank ２ Mass ΔM １ (kg) to ΔM １ = mC １ P １ F １ Δt / 100RT １ The calculation is based on the gas flow section 18 or CO discharged from the carbonation curing tank. ２ CO flowing through the gas outlet 16 ２ CO of gas containing ２ Concentration C ２ (vol%) and gas flow rate F ２ (m ３ / s) and pressure P ２ (Pa) and temperature T ２ (K) and CO ２ The molar mass m (kg / mol) and gas constant R = 8.31 (J / mol K) of CO flowing out from the carbonation curing tank ２ Mass ΔM ２ (kg) to ΔM ２ = mC ２ P ２ F ２ Δt / 100RT ２ Then, ΔM = ΔM １ -ΔM ２ By calculating the amount of CO absorbed by the concrete during Δt, ２ The mass ΔM of the concrete can be calculated. ２ O release or H by concrete ２ The mass change due to the absorption of O can be calculated by measuring the concentration of water vapor with a water vapor sensor and performing the same calculation as above. ２ By subtracting the amount of O released or absorbed, the amount of CO absorbed by the concrete during Δt can be calculated. ２ In this way, the mass ΔM of CO absorbed by the concrete can be calculated.２ When the mass ΔM is calculated, the integrated value M of ΔM in the i-th carbonation curing section from curing time 0 to t is ｉ This allows the timing of concrete removal to be determined. ２ When carbonation is performed in a system having n carbonation curing units with an absorption amount of M, the CO ２ Absorption amount M ｉ When the carbonation rate of the i-th carbonation curing section is slower than the average of all curing sections, the concrete can be removed and moved. ｉ < M / n, and if the carbonation of the i-th carbonation curing section is faster than the average of all curing sections, then M ｉ It is advisable to remove and move the concrete at >M / n. ２ Total absorption amount ΣM ｉ When the value of CO per curing section reaches M, ２ The absorption amount is M / n, so the target CO ２ It may also be determined that the absorption amount has been reached, and the concrete may be removed and moved. ｉ It is not necessary to wait until M is reached, for example, ΣM ｉ When the carbonation curing rate reaches 90% or more of M, it is determined that carbonation curing has been sufficiently performed, and the concrete may be removed and moved. The degree of progress of carbonation curing can also be determined by various solid analyses such as thermogravimetric and differential thermal analysis of the concrete, in addition to the magnitude of the degree of progress of carbonation curing described above.

[0019] The concrete pieces 22a, 22b, and 22c provided in the carbonation curing tanks 12a, 12b, and 12c are provided so as to be movable within the carbonation curing tanks 12a, 12b, and 12c by a transport mechanism 20. A dolly or the like can be used as the transport mechanism 20.

[0020] In addition, in order to efficiently perform carbonation curing in each of the carbonation curing tanks 12a, 12b, and 12c, CO ２It is preferable that the carbonation curing tanks 12a, 12b, and 12c are sealed except for the portions where the gas containing the carbon dioxide is supplied to and discharged from the carbonation curing tanks 12a, 12b, and 12c. The carbonation curing tanks 12a, 12b, and 12c have movable doors 24 (see FIG. 1(b)), which allow the concrete 22a, 22b, and 22c in the carbonation curing tanks 12a, 12b, and 12c to be carried in, taken out, and moved.

[0021] Next, the carbonation curing method of the carbonation curing system 10 according to this embodiment will be described. ２ The concretes 22a, 22b, and 22c are arranged along a flow path of the gas containing CO from the concrete 22a having a high degree of carbonation curing to the concrete 22c having a low degree of carbonation curing. ２ Since the high concentration gas can be reacted, the carbonation curing can be advanced for concrete in which the reaction has slowed down as the carbonation curing has progressed. Also, the gas supplied from the first carbonation curing tank 12a through the gas flow section 18 to the second carbonation curing tank 12b is difficult to carbonate in the first carbonation curing tank 12a, so the CO ２ is not consumed much, ２ A gas of a medium concentration is supplied. Therefore, carbonation curing can be performed on the concrete 22b in the second carbonation curing tank 12b, which has already been carbonated to a certain extent. Furthermore, the gas supplied from the second carbonation curing tank 12b through the gas flow section 18 to the third carbonation curing tank 12c contains CO because carbonation curing is being performed in the second carbonation curing tank 12b. ２ is consumed, and CO ２ However, the concrete 22c placed in the third carbonation curing tank 12c is concrete that has undergone carbonation curing to a low degree, and is therefore more likely to carbonate than the concrete placed in the first carbonation curing tank 12a and the second carbonation curing tank 12b. ２ Carbonation curing can be carried out even with low concentration gases.

[0022] In this way, CO ２ A gas containing CO ２By supplying the gas along the flow path of the gas containing CO 22 a so that the concrete 22 a has a high degree of carbonation curing progress and the concrete 22 c has a low degree of carbonation curing progress, the concrete 22 a has a high degree of carbonation curing progress and the gas containing CO 22 a ２ By contacting the concrete with a high concentration gas, it is possible to advance carbonation curing for concrete that is difficult to progress in carbonation curing. In addition, for concrete 22c that is in a low progress of carbonation curing, by passing it through the carbonation curing tanks 12a and 12b, ２ Although low concentration gases come into contact, the progress of carbonation curing is low, so CO ２ Even if a gas with a low concentration is brought into contact, carbonation curing can proceed. ２ CO in a gas containing ２ This allows for effective use of CO2, thereby improving the reaction efficiency. ２ can be reduced.

[0023] Furthermore, the carbonation reaction is an exothermic reaction, and if the reaction is rapid, the temperatures of the concrete and the curing chamber will rise, and the concrete will dry out. ２ The concrete 22b in which the carbonation curing is at a medium stage is brought into contact with a high concentration gas, and CO ２ A gas having a medium concentration is brought into contact with the concrete 22c having a low degree of carbonation curing, and CO ２ By contacting a low-concentration gas, the reaction rate and temperature are made uniform, which makes it possible to prevent uneven progress in the carbonation curing of the concrete and excessive drying.

[0024] After the carbonation curing in the first carbonation curing tank 12a is completed, the movable door 24 is opened as shown in FIG. 1(b), and the concrete 22a in the first carbonation curing tank 12a is removed. ２ Concrete 22b in the carbonation curing tank (in the second carbonation curing tank 12b) on the downstream side of the flow path of the gas containing CO is moved by the conveying mechanism 20 to the adjacent carbonation curing tank (in the first carbonation curing tank 12a) on the upstream side. ２Concrete 22c in a carbonation curing tank (in the third carbonation curing tank 12c) on the downstream side of the flow path of the gas containing the carbon dioxide is moved to an adjacent carbonation curing tank (in the second carbonation curing tank 12b) on the upstream side by the conveying mechanism 20. Then, uncured concrete 22d is placed in the carbonation curing tank (in the third carbonation curing tank 12c) on the most downstream side of the flow path.

[0025] After the concrete 22a has been taken out after the carbonation curing, ２ The concrete placed in the downstream carbonation curing tank is transported to the adjacent upstream carbonation curing tank along a flow path of the gas containing CO ２ By placing uncured concrete in the carbonation curing tank at the most downstream side of the gas flow path containing CO ２ Concrete can be installed along the flow path of the gas containing CO, from concrete with a high degree of carbonation curing to concrete with a low degree of carbonation curing. ２ Gas containing HCl can be efficiently used for carbonation curing.

[0026] The carbonation curing system of the present invention may have a conventional steam curing section in addition to the carbonation curing section where carbonation curing is performed. The concrete placed in the carbonation curing section may be concrete that has been cured with steam.

[0027] (Modification) Fig. 2 is a side view showing an outline of a modification of the carbonation curing system of the first embodiment. The carbonation curing system 50 shown in Fig. 2 is different from the carbonation curing system 10 shown in Fig. 1 in which each carbonation curing unit is provided individually, in that it has three carbonation curing units (a first carbonation curing unit 52a, a second carbonation curing unit 52b, and a third carbonation curing unit 52c (hereinafter collectively referred to as "carbonation curing units 52a, 52b, and 52c")) in one carbonation curing tank 51. The first carbonation curing unit 52a side in the carbonation curing tank 51 is provided with CO ２ The gas supply port 54 is connected to the third carbonation curing section 52c side. ２The carbonation curing tank 51 has a gas outlet 56, and a gas circulation section 58 is provided between each of the carbonation curing sections 52a, 52b, and 52c. This allows CO 2 to flow from the carbonation curing section 52a to the third carbonation curing section 52c within the carbonation curing tank 51. ２ This forms a distribution channel through which gas containing

[0028] In the carbonation curing system 50 shown in FIG. ２ The concrete 62a, 62b, 62c provided in each carbonation curing section 52a, 52b, 52c are provided along the flow path of the gas containing CO 2 , from the concrete 62a with a high degree of carbonation curing to the concrete 62c with a low degree of carbonation curing. By providing the concrete in this manner, the concrete 62a with a high degree of carbonation curing is filled with CO 2 , as in the carbonation curing system 10 shown in FIG. ２ By contacting the concrete with a high concentration gas, it is possible to advance carbonation curing for concrete that is difficult to progress in carbonation curing. In addition, for concrete 62c that is in a low stage of progress in carbonation curing, by passing it through the carbonation curing sections 52a and 52b, ２ Although low concentration gases come into contact, the progress of carbonation curing is low, so CO ２ Even if a gas with a low concentration is brought into contact, carbonation curing can proceed. ２ CO in a gas containing ２ This allows for effective use of CO2, thereby improving the reaction efficiency. ２ can be reduced.

[0029] The carbonation curing sections 52a, 52b, and 52c are provided with a conveying mechanism 60 such as a belt conveyor or a cart. The conveying mechanism 60 conveys the concrete 62b and 62c provided in each of the carbonation curing sections 52b and 52c to the CO ２The concrete 62a can be transported to the carbonation curing section upstream of the flow path of the gas containing carbon dioxide. When carbonation curing of the concrete 62a provided in the first carbonation curing section 52a is completed, the concrete 62a for which carbonation curing has been completed is removed from the first carbonation curing section 52a, as shown in FIG. 2(b). Then, the transport mechanism 60 moves the concrete 62b in the second carbonation curing section 52b to the first carbonation curing section 52a. Similarly, the transport mechanism 60 moves the concrete 62c in the third carbonation curing section 52c to the second carbonation curing section 52b. Then, uncured concrete 62d is placed in the third carbonation curing section 52c.

[0030] After the concrete 62a was taken out after the carbonation curing, ２ The concrete placed in the downstream carbonation curing section is transported to the adjacent upstream carbonation curing section along the flow path of the gas containing CO ２ By placing uncured concrete in the carbonation curing section at the most downstream side of the gas distribution path containing CO ２ Concrete can be installed along the flow path of the gas containing CO, from concrete with a high degree of carbonation curing to concrete with a low degree of carbonation curing. ２ Gas containing HCl can be efficiently used for carbonation curing.

[0031] <Second embodiment> Fig. 3 is a side view showing an outline of a carbonation curing system according to a second embodiment. The carbonation curing system according to the second embodiment includes four carbonation curing tanks, each of which contains CO ２ Supplying gas containing CO ２ Gas supply port, and CO ２ CO ２ A gas outlet is provided. ２ the location of the carbonation curing tank that supplies gas containing CO ２ It is now possible to change the position of the carbonation curing tank that discharges gases containing CO without moving the concrete in the carbonation curing tank. ２This carbonation curing system differs from the carbonation curing system of the first embodiment in that the flow path of the gas containing the carbonation curing system can be changed.

[0032] As shown in Fig. 3, the carbonation curing system 110 of the second embodiment includes a first carbonation curing tank 112a, a second carbonation curing tank 112b, a third carbonation curing tank 112c, and a fourth carbonation curing tank 112d (hereinafter collectively referred to as "carbonation curing tanks 112a, 112b, 112c, 112d"), which correspond to the carbonation curing sections of the present invention and perform carbonation curing of concrete. ２ Supplying gas containing CO ２ Gas supply ports 114a, 114b, 114c, 114d and CO ２ CO ２ Gas outlets 116a, 116b, 116c, and 116d are provided. CO 2 gas outlets are provided between the first carbonation curing tank 112a and the second carbonation curing tank 112b, between the second carbonation curing tank 112b and the third carbonation curing tank 112c, between the third carbonation curing tank 112c and the fourth carbonation curing tank 112d, and between the fourth carbonation curing tank 112d and the first carbonation curing tank 112a. ２ The gas flow section 118 is provided with a gas flow section 118 that flows a gas containing CO ２ Gas supply ports 114a, 114b, 114c, 114d, and CO ２ The gas outlets 116a, 116b, 116c, and 116d are common to each other and are provided by branching using a valve 126. ２ Gas supply ports 114a, 114b, 114c, 114d, and CO ２ Although the gas outlets 116 a , 116 b , 116 c , and 116 d are partially provided in common with the gas circulating part 118 , they may also be provided separately from the gas circulating part 118 .

[0033] In addition, each CO ２ Gas supply ports 114a, 114b, 114c, and 114d, and their respective CO ２ Gas outlets 116a, 116b, 116c, and 116d are connected to a valve 126 to supply CO ２The carbonation curing tank that supplies and discharges gas containing CO ２ the location of the carbonation curing tank that supplies gas containing CO ２ It is now possible to change the location of the carbonation curing tank that discharges gases containing CO ２ It is possible to change the gas distribution route, including

[0034] The carbonation curing tanks 112a, 112b, 112c, and 112d are provided with concrete 122a, 122b, 122c, and 122d, each of which is at a different stage of carbonation curing. ２ The concrete 122a is provided with a high degree of carbonation curing progress along the flow path of the gas containing CO 2 in the first carbonation curing tank 112a, and the concrete 122d is provided with a low degree of carbonation curing progress along the flow path of the gas containing CO 2 in the first carbonation curing tank 112a. ２ CO is supplied to the carbonation curing system 110 from the gas supply port 114a. ２ and supplying a gas containing CO to the fourth carbonation curing tank 112d. ２ CO from the gas outlet 116d ２ At this time, gas containing CO passes through the gas circulation part 118 from the first carbonation curing tank 112a to the second carbonation curing tank 112b, from the second carbonation curing tank 112b to the third carbonation curing tank 112c, and from the third carbonation curing tank 112c to the fourth carbonation curing tank 112d. ２ The valve 126 is controlled so that the gas containing CO ２ The flow path for the gas containing carbon dioxide is a flow path from the first carbonation curing tank 112 a to the fourth carbonation curing tank 112 d. The concrete is arranged in the following order: concrete 122 a having the highest degree of carbonation curing is provided in the first carbonation curing tank 112 a, concrete 122 b having a fairly high degree of carbonation curing is provided in the second carbonation curing tank 112 b, concrete 122 c having a relatively low degree of carbonation curing is provided in the third carbonation curing tank 112 c, and concrete 122 d having a low degree of carbonation curing is provided in the fourth carbonation curing tank 112 d.

[0035] Each of the carbonation curing tanks 112a, 112b, 112c, and 112d is configured to efficiently perform carbonation curing in the carbonation curing tanks. ２ It is preferable that the carbonation curing tanks 112a, 112b, 112c, and 112d are sealed except for the portions where the gas containing

[0036] Next, the carbonation curing method of the carbonation curing system 110 according to this embodiment will be described. ２ Concrete is provided along the flow path of the gas containing carbon dioxide, from concrete 122a with a high degree of carbonation curing to concrete 122d with a low degree of carbonation curing.

[0037] By arranging the concrete 122a, 122b, 122c, and 122d in this manner, the CO ２ Since it is possible to react gases with high concentrations, it is possible to proceed with carbonation curing on concrete whose reaction has slowed down as carbonation curing has progressed. Also, the gas supplied from the first carbonation curing tank 112a through the gas flow section 118 to the second carbonation curing tank 112b is difficult to carbonate in the first carbonation curing tank 112a, so the gas ２ is not consumed much, ２ Therefore, it is possible to cure the concrete 122b in the second carbonation curing tank 112b, which has already been carbonated to a certain extent. Furthermore, the gas supplied from the second carbonation curing tank 112b through the gas flow section 118 to the third carbonation curing tank 112c contains CO because carbonation curing is being performed in the second carbonation curing tank 112b. ２ is consumed, and CO ２ However, the concrete 122c provided in the third carbonation curing tank 112c is concrete that has undergone carbonation curing to a relatively low degree, and is more likely to carbonate than the concretes 122a and 122b provided in the first carbonation curing tank 112a and the second carbonation curing tank 112b. ２Similarly, in the fourth carbonation curing tank 112d, the gas supplied from the third carbonation curing tank 112c through the gas flow section 118 to the fourth carbonation curing tank 112d is converted into CO ２ is consumed, and CO ２ However, the concrete 122d provided in the fourth carbonation curing tank 112d is concrete that has undergone carbonation curing to a low degree, and is more likely to carbonate than the concrete provided in the first carbonation curing tank 112a, the second carbonation curing tank 112b, and the third carbonation curing tank 112c. ２ Carbonation curing can be carried out even with low concentration gases.

[0038] In this way, CO ２ A gas containing CO ２ By supplying the gas containing CO along the flow path from concrete 122a having a high degree of carbonation curing to concrete 122d having a low degree of carbonation curing, the concrete 122a having a high degree of carbonation curing is supplied with CO ２ By contacting the concrete with a high concentration gas, it is possible to advance carbonation curing on concrete that is difficult to progress in carbonation curing. In addition, for concrete 122d that is in a low progress of carbonation curing, by passing it through a carbonation curing tank, ２ Although low concentration gases come into contact, the progress of carbonation curing is low, so CO ２ By contacting the gas with a low concentration, carbonation curing can be promoted. ２ CO in a gas containing ２ This allows for effective use of CO2, thereby improving the reaction efficiency. ２ can be reduced.

[0039] Furthermore, the carbonation reaction is an exothermic reaction, and if the reaction is rapid, the temperatures of the concrete and the curing chamber will rise, and the concrete will dry out. ２ The concrete 22b in which the carbonation curing is at a medium stage is brought into contact with a high concentration gas, and CO ２A gas having a medium concentration is brought into contact with the concrete 22c having a low degree of carbonation curing, and CO ２ By contacting a low-concentration gas, the reaction rate and temperature are made uniform, which makes it possible to prevent uneven progress in the carbonation curing of the concrete and excessive drying.

[0040] When carbonation curing in the first carbonation curing tank 112a is completed, the concrete 122a is removed from the first carbonation curing tank 112a, as shown in Figure 3(b). After the concrete 122a is removed from the first carbonation curing tank 112a, uncured concrete 122e is placed in the first carbonation curing tank 112a. By placing the concrete in this manner, the concrete in the carbonation curing tanks is arranged in the order of decreasing carbonation curing progress, from the second carbonation curing tank 112b, the third carbonation curing tank 112c, the fourth carbonation curing tank 112d, and the first carbonation curing tank 112a.

[0041] After the uncured concrete 122e is placed in the first carbonation curing tank 112a, ２ The gas containing CO is supplied to the carbonation curing system 110. ２ The gas containing ２ The valve 126 is controlled so that the carbonation curing tank downstream of the flow path of the gas containing CO, i.e., the second carbonation curing tank 112b, is started. ２ The valve 126 is controlled so that the gas containing CO is discharged from the carbonation curing section where the uncured concrete is placed, i.e., the first carbonation curing tank 112a. Specifically, the valve 126 of the gas supply port 114b provided in the second carbonation curing tank 112b is opened from the flow path in the case of FIG. 3(a). ２ The valve 126 of the gas outlet 116a provided in the first carbonation curing tank 112a is changed to the exhaust side, and CO is introduced into the gas flow section 118 between the first carbonation curing tank 112a and the second carbonation curing tank 112b. ２Then, the valve 126 is controlled so that the gas passes through the gas flow section 118 between the fourth carbonation curing tank 112d and the first carbonation curing tank 112a. ２ The flow path of the gas containing carbon dioxide is the second carbonation curing tank 112b, the third carbonation curing tank 112c, the fourth carbonation curing tank 112d, and the first carbonation curing tank 112a, so that the concrete 122b with a high degree of carbonation curing progresses to the concrete 122e with a low degree of carbonation curing progress.

[0042] After that, the concrete that has been carbonated and cured is removed, and uncured concrete is placed in place. Then, CO2 is pumped from the downstream carbonation curing tank where the uncured concrete is placed to the carbonation curing tank where the uncured concrete is placed. ２ By using this as a flow path for gas containing CO, for concrete with a high degree of carbonation curing ２ For concrete with high concentration of gases and low progress of carbonation curing, CO ２ By contacting with low concentration gas, CO ２ can be used efficiently for carbonation curing.

[0043] (Modification) Figure 4 is a top view showing an outline of a modification of the carbonation curing system of the second embodiment. The carbonation curing system 150 shown in Figure 4 is different from the carbonation curing system 110 shown in Figure 3 in that a single carbonation curing tank 151 is divided by walls 153 to provide four carbonation curing units (a first carbonation curing unit 152a, a second carbonation curing unit 152b, a third carbonation curing unit 152c, and a fourth carbonation curing unit 152d (hereinafter collectively referred to as "carbonation curing units 152a, 152b, 152c, and 152d").

[0044] In addition, in the carbonation curing system 150 shown in FIG. 4, CO ２ Supplying gas containing CO ２ Gas supply ports 154a, 154b, 154c, 154d and CO ２ CO ２Gas outlets 156a, 156b, 156c, and 156d are provided. Furthermore, CO 2 gases are provided between the first carbonation curing section 152a and the second carbonation curing section 152b, between the second carbonation curing section 152b and the third carbonation curing section 152c, between the third carbonation curing section 152c and the fourth carbonation curing section 152d, and between the fourth carbonation curing section 152d and the first carbonation curing section 152a. ２ The gas flow section 158 is provided with a gas flow section 158 that flows a gas containing CO ２ It is preferable that the gas passage is provided so as to be openable and closable so that the order in which the gas containing the carbonation curing agent flows through the different carbonation curing sections can be controlled.

[0045] Each CO ２ Gas supply ports 154a, 154b, 154c, and 154d, and their respective CO ２ Gas outlets 156a, 156b, 156c, and 156d are connected to a valve 166 to allow CO ２ The carbonation curing tank that supplies and discharges gas containing CO ２ the location of the carbonation curing tank that supplies gas containing CO ２ It is now possible to change the location of the carbonation curing tank that discharges gases containing CO ２ It is possible to change the gas distribution route, including

[0046] In FIG. 4(a), the CO ２ The valve 166 of the gas supply port 154a and the CO ２ By opening the valve 166 of the gas outlet 156d and closing the other valves 166, the CO ２ CO is supplied to the carbonation curing system 150 from the gas supply port 154a. ２ and supplying a gas containing CO ２ CO from the gas outlet 156d ２ At this time, the gas containing CO is discharged from the fourth carbonation curing section 152d to the first carbonation curing section 152a. ２ It is preferable to close the gas flow section 158 between the fourth carbonation curing section 152d and the first carbonation curing section 152a so that gas containing the carbon dioxide does not flow.

[0047] In the carbonation curing system 150 shown in FIG. ２ By providing the carbonation curing sections 152a, 152b, 152c, and 152d along the flow path of the gas containing CO , from concrete with a high degree of carbonation curing to concrete with a low degree of carbonation curing, ２ CO in a gas containing ２ This allows for effective use of CO2, thereby improving the reaction efficiency. ２ can be reduced.

[0048] After the carbonation curing of the concrete 162a provided in the first carbonation curing section 152a is completed, as shown in FIG. 4(b), the CO ２ The valve 166 of the gas supply port 154a and the CO ２ The valve 166 of the gas outlet 156d is closed, and the gas circulation parts 158 of the fourth carbonation curing part 152d and the first carbonation curing part 152a are opened. Then, the concrete 162a is removed from the first carbonation curing part 152a, and uncured concrete 162e is placed in the first carbonation curing part 152a. Thereafter, the gas circulation parts 158 of the first carbonation curing part 152a and the second carbonation curing part 152b are closed, and the CO 2 of the second carbonation curing part 152b is opened. ２ The valve 166 of the gas supply port 154b and the CO ２ The valve 166 of the gas outlet 156a is opened. This causes the CO ２ CO from the gas supply port 154b ２ and CO is supplied through the flow paths of the second carbonation curing section 152b, the third carbonation curing section 152c, the fourth carbonation curing section 152d, and the first carbonation curing section 152a. ２ and supplying a gas containing CO ２ By using such a flow path, CO 2 can be discharged from the gas outlet 156 a to the concrete 162 b with a high degree of carbonation curing toward the concrete 162 e with a low degree of carbonation curing. ２ Since it is possible to supply a gas containing CO２ can be effectively used, and the reaction efficiency can be improved.

[0049] According to the carbonation curing system and carbonation curing method of the present invention, CO is applied to concrete that has undergone a high degree of carbonation curing. ２ High concentration gas is brought into contact with concrete that has not yet progressed in carbonation curing, ２ By contacting a low-concentration gas, carbonation curing of concrete can be carried out with high reaction efficiency and the curing time can also be shortened.

[0050] The carbonation curing system and carbonation curing method of the present invention have a high reaction rate in a short time, allowing for more efficient curing, and the resulting hardened body can be suitably used particularly in the fields of civil engineering and construction.

[0051] 10, 50, 110, 150 Carbonation curing system 12a, 12b, 12c, 112a, 112b, 112c, 112d Carbonation curing tank 14, 54, 114a, 114b, 114c, 114d, 154a, 154b, 154c, 154d CO ２ Gas supply ports 16, 56, 116a, 116b, 116c, 116d, 156a, 156b, 156c, 156d CO ２ Gas exhaust port 18 58 118 158 Gas circulation section 20, 60 Conveyance mechanism 22a, 22b, 22c, 22d, 62a, 62b, 62c, 62d, 122a, 122b, 122c, 122d, 122e, 162a, 162b, 162c, 162d, 162e Concrete 24 Movable door 51, 151 Carbonation curing tank 52a, 52b, 52c, 152a, 152b, 152c, 152d Carbonation curing section 126, 166 Valve 153 Wall

Claims

1. A carbonation curing system used in the production of concrete, comprising at least two or more carbonation curing sections, and a carbonation curing section provided between each of the carbonation curing sections, and a carbonation curing section between the carbonation curing sections. ２ a gas distribution unit for distributing a gas containing CO ２ Supplying gas containing CO ２ A gas supply port and CO from the system ２ Reduced CO concentration ２ CO ２ a gas outlet, ２ A gas supply port is provided in at least one of the carbonation curing sections, and the CO ２ The gas outlet is the CO ２ The carbonation curing section is provided in at least one of the carbonation curing sections different from the carbonation curing section provided with the gas supply port, and concrete having a different degree of carbonation curing is provided in each of the carbonation curing sections, and the CO ２ A gas containing CO ２ A carbonation curing system that supplies gas containing the above along a gas flow path so that concrete with a high degree of carbonation curing progresses to concrete with a low degree of carbonation curing progress.

2. After the concrete has been carbonated, remove it and ２ 2. The carbonation curing system according to claim 1, wherein concrete in the carbonation curing section downstream of a flow path of the gas containing the carbonation curing agent is transported to the carbonation curing section upstream of the flow path, and uncured concrete is placed in the carbonation curing section furthest downstream of the flow path.

3. Add the CO ２ gas supply port, and the CO ２ A gas outlet is provided, and the CO ２ gas supply port, and the CO ２ The gas outlet is ２ the carbonation curing unit that supplies a gas containing ２ Reduced CO concentration ２ a valve for changing the carbonation curing section from which a gas containing CO is discharged, and after removing the concrete that has been carbonation cured, uncured concrete is placed in the removed carbonation curing section; ２ The supply of gas containing CO ２ a flow path for a gas containing CO ２ Reduced CO concentration ２ 2. The carbonation curing system according to claim 1, wherein the carbonation curing section is configured to discharge the gas containing the above-mentioned carbon dioxide from the carbonation curing section in which uncured concrete is placed.

4. A carbonation curing method used in the production of concrete, comprising: at least two or more carbonation curing sections each having concrete with different degrees of carbonation curing progress; and carbon dioxide is added to the concrete so that the degree of carbonation curing progresses from high to low. ２ A carbonation curing method comprising supplying a gas containing 5. The concrete that has been carbonated and cured is removed from the carbonation curing section, and the CO ２ 5. The carbonation curing method according to claim 4, wherein concrete in the carbonation curing section downstream of a flow path of the gas containing the compound is transported to the carbonation curing section upstream of the flow path, and uncured concrete is placed in the carbonation curing section furthest downstream of the flow path.

6. The concrete that has been carbonated and cured is removed from the carbonation curing section, and uncured concrete is placed in the carbonation curing section. ２ The supply of gas containing CO ２ a gas flow path including the carbonation curing section downstream of the carbonation curing section where uncured concrete is installed, ２ Reduced CO concentration ２ The carbonation curing method according to claim 4, wherein the gas containing the above is discharged from the carbonation curing section in which uncured concrete is placed.

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