Materials containing voids, building materials, concrete additives, methods for using concrete additives, methods for manufacturing materials containing voids, carbon dioxide enrichment apparatus

Abstract

To utilize waste concrete, we aim to sequester carbon dioxide from the atmosphere. [Solution] A substance having voids 304, wherein the porosity of the voids 304 is 5% or more and less than 50%, and there is a portion of the voids 304 where the concentration of carbon dioxide is higher than the concentration of carbon dioxide in the atmosphere. Preferably, the substance contains calcium carbonate or calcium oxide as part of it, and waste concrete from which carbon dioxide has been absorbed is preferably used. By adding a void-containing substance such as waste concrete to concrete, carbon dioxide can be absorbed efficiently.

Description

Technical Field

[0001] The present invention relates to confining carbon dioxide in voids of a substance having voids.

Background Art

[0002] Due to the demolition of buildings, a large amount of waste concrete fragments are generated, and the generated large amount of waste concrete fragments are used as additives for concrete as part of resource recycling. Also, wastes such as shells, carbon materials, and coke are used as additives for concrete. In particular, calcium carbonate derived from waste concrete and waste shells fixes carbon dioxide and is used as part of concrete.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] As a method for fixing carbon dioxide to waste concrete and waste shells (hereinafter also referred to as "target objects"), carbon dioxide is supplied from the surface of the target part to the target object to fix carbon dioxide. Also, when the target object has voids, carbon dioxide is supplied into the voids, and carbon dioxide is fixed to the inside of the target object through the surface of the target object and the voids of the target object.

[0005] Techniques for fixing carbon dioxide to a target object are sometimes called carbonation curing or sometimes called neutralization reaction. Typically, when carbon dioxide (CO2) is fixed to calcium oxide (CaO), the calcium oxide is neutralized to become calcium carbonate (CaCO3).

[0006] Calcium carbonate can sequester carbon dioxide and is commonly used as an ingredient in concrete. Calcium carbonate can sequester 0.44 kg of carbon dioxide per kg.

[0007] Another method of carbon dioxide fixation that has already been investigated involves supplying carbon dioxide to the voids in particulate additives and fixing the carbon dioxide to unneutralized calcium oxide inside the additives.

[0008] Figure 9 shows a cross-sectional image of the object 300 in the conventional technology after carbon dioxide fixation and neutralization reactions have occurred. Figure 10 shows a magnified view of the main part of Figure 9. Carbon dioxide is present around the object 300 shown in Figure 9. Here, the shape of the object 300 is shown as having a circular cross-section, but in reality, it has various shapes other than circular. Also, the shaded area shown on the object 300 indicates the neutralized part. In Figure 9, one void 304 is shown in the object 300, but in reality, numerous voids 304 exist in various shapes.

[0009] As illustrated in Figure 9, when object 300 is exposed to a carbon dioxide atmosphere to neutralize it, the neutralization reaction occurs from the surface of object 300 that is in contact with the carbon dioxide. However, even when object 300 is placed in a carbon dioxide atmosphere and neutralized by bringing carbon dioxide into contact with its surface, only the surface of object 300 is neutralized to a thin layer, and the interior of object 300 is not neutralized to a depth of about 10 μm from the part of the surface of object 300 that is in contact with carbon dioxide.

[0010] Furthermore, as illustrated in Figure 10, when there is a void 304 in the object 300, carbon dioxide penetrates from the surface of the object 300 into the void 304. However, air (air portion 312) is present inside the void 304, and the air inhibits the penetration of carbon dioxide into the void 304. Figure 10 shows the state where carbon dioxide has penetrated from the surface of the object 300 to the boundary 316. It can be seen that in the void 304, a neutralization reaction occurs in the area where carbon dioxide has penetrated, but not in the area where carbon dioxide has not penetrated.

[0011] As described above, in conventional technology, even when attempting to induce a neutralization reaction in the object 300 with carbon dioxide, only the surface of the object 300 that comes into contact with carbon dioxide and the parts of the voids 304 in the object 300 where carbon dioxide is present undergo the neutralization reaction. Therefore, it was difficult to obtain an object 300 that had undergone a sufficient neutralization reaction.

[0012] In particular, it was believed that there was room for improvement in materials with high porosity, but no concrete solution had been found. [Means for solving the problem]

[0013] One embodiment of the present invention is a material having voids 304, wherein the porosity of the voids 304 is 5% or more and less than 50%, and there is a portion of the voids 304 where the concentration of carbon dioxide is higher than the concentration of carbon dioxide in the atmosphere.

[0014] One embodiment of the present invention is a building material comprising a substance having voids 304, wherein the porosity of the voids 304 is 5% or more and less than 50%, there is a portion of the voids 304 where the concentration of carbon dioxide is higher than the concentration of carbon dioxide in the atmosphere, and part of the substance contains calcium carbonate.

[0015] One embodiment of the present invention is a building material comprising a substance having voids 304, wherein the porosity of the voids 304 is 5% or more and less than 50%, there is a portion of the voids 304 where the concentration of carbon dioxide is higher than the concentration of carbon dioxide in the atmosphere, and a portion of the substance contains calcium oxide.

[0016] One embodiment of the present invention is a building material comprising a substance having voids 304, wherein the porosity of the voids 304 is 5% or more and less than 50%, and there is a portion of the voids 304 where the concentration of carbon dioxide is higher than the concentration of carbon dioxide in the atmosphere, and part of the substance contains calcium carbonate and calcium oxide.

[0017] One embodiment of the present invention is a concrete additive 300 having voids 304, wherein the void ratio of the voids 304 is 5% or more and less than 50%, there is a portion of the voids 304 where the concentration of carbon dioxide is higher than the concentration of carbon dioxide in the atmosphere, and a portion of the concrete additive 300 contains calcium carbonate and calcium oxide.

[0018] One embodiment of the present invention is a method for using a concrete additive 300 having voids 304, wherein the void ratio of the voids 304 is 5% or more and less than 50%, there is a portion of the voids 304 where the concentration of carbon dioxide is higher than the concentration of carbon dioxide in the atmosphere, a portion of the concrete additive 300 contains calcium carbonate and calcium oxide, and the concrete additive 300 is mixed with concrete building materials while the concentration of carbon dioxide in the voids 304 is higher than the concentration of carbon dioxide in the atmosphere, thereby promoting at least one of the neutralization or hydration reaction of the concrete building materials.

[0019] One embodiment of the present invention is that the concentration of carbon dioxide in the voids 304 of the material is 500,000 ppm or more.

[0020] One embodiment of the present invention is a method for producing a substance, which involves placing a substance having voids 304 with a porosity of 5% or more and less than 50% in a space where the concentration of carbon dioxide is higher than the concentration of carbon dioxide in the atmosphere, and then increasing the pressure in the space by reducing and increasing the pressure.

[0021] One embodiment of the present invention is a method for producing a substance, which involves placing a substance having voids 304 with a porosity of 5% or more and less than 50% in a space where the concentration of carbon dioxide is higher than the concentration of carbon dioxide in the atmosphere, and then repeatedly reducing and increasing the pressure in the space to increase the concentration of carbon dioxide in the voids 304 of the substance.

[0022] One embodiment of the present invention is a carbon dioxide enrichment apparatus comprising: a processing apparatus capable of placing a substance inside; a carbon dioxide supply device capable of supplying carbon dioxide to the processing apparatus; a pressure reducing device capable of reducing the pressure in the processing chamber 222 of the processing apparatus; and a pressure increasing device capable of increasing the pressure in the processing chamber 222 of the processing apparatus, wherein carbon dioxide enrichment is performed by a pressure reducing step of operating the pressure reducing device with a substance having a porosity of 5% or more and less than 50% placed in the processing chamber 222 of the processing apparatus; a carbon dioxide supply step of operating the carbon dioxide supply device with the substance placed in the processing chamber 222 of the processing apparatus; and a pressure increasing step of operating the pressure increasing device with the substance placed in the processing chamber 222 of the processing apparatus, thereby enriching the voids 304 of the substance with carbon dioxide.

[0023] One embodiment of the present invention is a carbon dioxide enrichment device comprising a processing device capable of disposing a substance therein, a carbon dioxide supply device capable of supplying carbon dioxide to the processing device, a decompression device capable of decompressing the pressure in the processing chamber 222 of the processing device, and a pressurization device capable of pressurizing the pressure in the processing chamber 222 of the processing device. The method includes a decompression step of operating the decompression device while disposing a substance having a porosity of 5% or more and less than 50% in the processing chamber 222 of the processing device and setting the temperature in the processing chamber 222 of the processing device to 25 degrees or more, a carbon dioxide supply step of operating the carbon dioxide supply device while disposing the substance in the processing chamber 222 of the processing device, and a pressurization step of operating the pressurization device while disposing the substance in the processing chamber 222 of the processing device, thereby enriching carbon dioxide in the voids 304 of the substance.

[0024] One embodiment of the present invention is a carbon dioxide enrichment device comprising a processing device capable of disposing a substance therein, a carbon dioxide supply device capable of supplying carbon dioxide to the processing device, and a decompression device capable of decompressing the pressure in the processing chamber 222 of the processing device. The method includes a decompression step of operating the decompression device while disposing a substance having a porosity of 5% or more and less than 50% in the processing chamber 222 of the processing device and setting the temperature in the processing chamber 222 of the processing device to 25 °C or more, and a carbon dioxide supply step of operating the carbon dioxide supply device while disposing the substance in the processing chamber 222 of the processing device to increase the pressure in the processing chamber 222 of the processing device, thereby enriching carbon dioxide in the voids 304 of the substance having voids 304 with a porosity of 5% or more and less than 50%.

[0025] One embodiment of the present invention includes a processing device capable of disposing a substance therein, a carbon dioxide supply device capable of supplying carbon dioxide to the processing device, and a pressure reducing device capable of reducing the pressure in the processing chamber 222 of the processing device. A substance having a porosity of 5% or more and less than 50% is disposed in the processing chamber 222 of the processing device, and a pressure reducing step of operating the pressure reducing device with the temperature in the processing chamber 222 of the processing device being 100°C or higher, and a carbon dioxide supply step of disposing a substance having a porosity of 5% or more and less than 50% in the processing chamber 222 of the processing device and increasing the pressure in the processing chamber 222 of the processing device by operating the carbon dioxide supply device with the temperature in the processing chamber 222 of the processing device being 25°C or lower are performed, thereby enriching carbon dioxide in the voids 304 of the substance. It is a carbon dioxide enrichment device.

[0026] One embodiment of the present invention includes a processing device capable of disposing a substance therein, a carbon dioxide supply device capable of supplying carbon dioxide to the processing device, and a pressure reducing device capable of reducing the pressure in the processing chamber 222 of the processing device. A substance having a porosity of 5% or more and less than 50% is disposed in the processing chamber 222 of the processing device, and a pressure reducing step of operating the pressure reducing device with the temperature in the processing chamber 222 of the processing device being 100°C or higher, and a carbon dioxide supply step of disposing the substance in the processing chamber 222 of the processing device and increasing the pressure in the processing chamber 222 of the processing device by operating the carbon dioxide supply device with the temperature in the processing chamber 222 of the processing device being 25°C or lower are performed, thereby enriching carbon dioxide in the voids 304 of the substance. It is a carbon dioxide enrichment device.

Advantages of the Invention

[0027] In a substance having voids 304 according to one embodiment of the present invention, the porosity of the voids 304 is 5% or more and less than 50%. Since there is a portion where the concentration of carbon dioxide in the voids 304 is higher than the concentration of carbon dioxide in the atmosphere, many portions are neutralized, and a substance having voids 304 carrying carbon dioxide can be used as a building material or as a concrete additive 300.

[0028] In one embodiment of the present invention, a material having voids 304, wherein the porosity of the voids 304 is 5% or more and less than 50%, and there is a portion of the voids 304 where the concentration of carbon dioxide is higher than the concentration of carbon dioxide in the atmosphere, and a portion of the material contains calcium carbonate, and by making it a building material, a large portion is neutralized, and the material having carbon dioxide-supported voids 304 can be utilized as a building material.

[0029] In one embodiment of the present invention, a material having voids 304, wherein the porosity of the voids 304 is 5% or more and less than 50%, there is a portion of the voids 304 where the concentration of carbon dioxide is higher than the concentration of carbon dioxide in the atmosphere, and a portion of the material contains calcium oxide. By making this material a building material, a large portion is neutralized, and the material having carbon dioxide-supported voids 304 can be utilized as a building material.

[0030] In one embodiment of the present invention, a material having voids 304, wherein the porosity of the voids 304 is 5% or more and less than 50%, and there is a portion of the voids 304 where the concentration of carbon dioxide is higher than the concentration of carbon dioxide in the atmosphere, and a portion of the material contains calcium carbonate and calcium oxide, and when used as a building material, a large portion is neutralized, and the material having carbon dioxide-supported voids 304 can be utilized as a building material.

[0031] In one embodiment of the present invention, a concrete additive 300 having voids 304, wherein the porosity of the voids 304 is 5% or more and less than 50%, and there is a portion of the voids 304 where the concentration of carbon dioxide is higher than the concentration of carbon dioxide in the atmosphere, and a portion of the concrete additive 300 contains calcium carbonate and calcium oxide, thereby a large portion of the concrete additive 300 is neutralized, and the substance having carbon dioxide-supported voids 304 can be utilized as a building material.

[0032] In one embodiment of the present invention, a method for using a concrete additive 300 having voids 304, wherein the porosity of the voids 304 is 5% or more and less than 50%, there is a portion of the voids 304 where the concentration of carbon dioxide is higher than the concentration of carbon dioxide in the atmosphere, a portion of the concrete additive 300 contains calcium carbonate and calcium oxide, and by mixing the concrete additive 300 with concrete building materials while the concentration of carbon dioxide in the voids 304 is higher than the concentration of carbon dioxide in the atmosphere, at least one of the neutralization or hydration reaction of the concrete building material is promoted. As a result, a large portion is neutralized, and a substance having carbon dioxide-supported voids 304 can be utilized as a concrete additive 300.

[0033] In one embodiment of the present invention, by setting the carbon dioxide concentration in the voids 304 of the material to 500,000 ppm or more, the material having voids 304 can be effectively utilized as a carbon dioxide carrier.

[0034] In one embodiment of the present invention, a material having voids 304 with a porosity of 5% or more and less than 50% is placed in a space where the concentration of carbon dioxide is higher than the concentration of carbon dioxide in the atmosphere. By increasing and decreasing the pressure in the space in this manner, the concentration of carbon dioxide in the voids 304 of the material can be easily increased.

[0035] In one embodiment of the present invention, a material having voids 304 with a porosity of 5% or more and less than 50% is placed in a space where the concentration of carbon dioxide is higher than the concentration of carbon dioxide in the atmosphere. By repeatedly reducing and increasing the pressure in the space, the concentration of carbon dioxide in the voids 304 of the material is increased by a method for producing the material, it is possible to easily increase the concentration of carbon dioxide in the voids 304 of the material having voids 304.

[0036] One embodiment of the present invention provides a carbon dioxide enrichment device that includes a processing apparatus capable of containing a substance, a carbon dioxide supply device capable of supplying carbon dioxide to the processing apparatus, a pressure reducing device capable of reducing the pressure in the processing chamber 222 of the processing apparatus, and a pressure increasing device capable of increasing the pressure in the processing chamber 222 of the processing apparatus. The carbon dioxide enrichment device enriches the voids 304 of the substance by performing a pressure reducing step of operating the pressure reducing device with a substance having a void ratio of 5% or more and less than 50% placed in the processing chamber 222 of the processing apparatus, a carbon dioxide supply step of operating the carbon dioxide supply device with the substance placed in the processing chamber 222 of the processing apparatus, and a pressure increasing step of operating the pressure increasing device with the substance placed in the processing chamber 222 of the processing apparatus, thereby enriching the voids 304 of the substance with carbon dioxide.

[0037] One embodiment of the present invention provides a carbon dioxide enrichment device that includes a processing apparatus capable of containing a substance, a carbon dioxide supply device capable of supplying carbon dioxide to the processing apparatus, a pressure reducing device capable of reducing the pressure in the processing chamber 222 of the processing apparatus, and a pressure increasing device capable of increasing the pressure in the processing chamber 222 of the processing apparatus. The carbon dioxide enrichment device enriches the voids 304 of a substance by performing a pressure reduction step in which a substance with a porosity of 5% or more and less than 50% is placed in the processing chamber 222 of the processing apparatus and the pressure reducing device is operated at a temperature of 25 degrees Celsius or higher; a carbon dioxide supply step in which the carbon dioxide supply device is operated with the substance placed in the processing chamber 222 of the processing apparatus; and a pressure increasing step in which the pressure increasing device is operated with the substance placed in the processing chamber 222 of the processing apparatus, thereby enriching the voids 304 of the substance with carbon dioxide.

[0038] One embodiment of the present invention is a carbon dioxide enrichment device that enriches the voids 304 of a substance having voids 304 with carbon dioxide by performing a depressurization step of operating the depressurization device while the temperature of the processing chamber 222 of the processing device is set to 25°C or higher, and a carbon dioxide supply step of increasing the pressure of the processing chamber 222 of the processing device by operating the carbon dioxide supply device while the substance is placed in the processing chamber 222 of the processing device, thereby enriching the voids 304 of a substance having voids 304 with carbon dioxide, thereby making it easier to increase the concentration of carbon dioxide in the voids 304 of a substance having voids 304.

[0039] One embodiment of the present invention provides a carbon dioxide enrichment device that enriches the voids 304 of a substance by performing a depressurization step in which a substance having a porosity of 5% or more and less than 50% is placed in the processing chamber 222 of the processing device and the depressurization device is operated when the temperature of the processing chamber 222 of the processing device is 100°C or higher, and a carbon dioxide supply step in which a substance having a porosity of 5% or more and less than 50% is placed in the processing chamber 222 of the processing device and the temperature of the processing chamber 222 of the processing device is 25°C or lower and the pressure of the processing chamber 222 of the processing device is increased by operating the carbon dioxide supply device, thereby enriching the voids 304 of the substance with carbon dioxide.

[0040] One embodiment of the present invention provides a carbon dioxide enrichment device that enriches the voids 304 of a substance by performing a depressurization step in which a substance having a porosity of 5% or more and less than 50% is placed in the processing chamber 222 of the processing device and the depressurization device is operated when the temperature of the processing chamber 222 of the processing device is 100°C or higher, and a carbon dioxide supply step in which the substance is placed in the processing chamber 222 of the processing device and the pressure of the processing chamber 222 of the processing device is increased by operating the carbon dioxide supply device when the temperature of the processing chamber 222 of the processing device is 25°C or lower, thereby enriching the voids 304 of the substance with carbon dioxide. [Brief explanation of the drawing]

[0041] [Figure 1] This diagram shows the flow for fixing carbon dioxide in additive 300. [Figure 2] This diagram shows the flow from creating additive 300 from building materials to adding it to concrete material 314 to create building materials. [Figure 3] This is a diagram showing the flow of the grinding process. [Figure 4] This is a schematic diagram of a carbon dioxide pressurizing device that can pressurize and depressurize carbon dioxide relative to additive 300 in order to fix carbon dioxide in additive 300. [Figure 5] This is a conceptual diagram showing the state in which carbon dioxide is fixed on the surface of additive 300 and inside the voids 304. [Figure 6] Figure 5 is an enlarged view of the main part. [Figure 7] This figure shows the initial state of concrete building material after additive 300 has been mixed in. [Figure 8] This figure shows the state after the neutralization reaction has progressed when additive 300 has been mixed into concrete building materials. [Figure 9] This diagram shows the neutralization reaction of object 300 using conventional technology. [Figure 10] This is an enlarged view of the main part of Figure 9. [Modes for carrying out the invention]

[0042] Hereinafter, an example of a material having voids 304, which is one embodiment of the present invention, will be described with reference to the attached drawings, in which the porosity of the voids 304 is 5% or more and less than 50%, and there is a portion of the voids 304 where the concentration of carbon dioxide is higher than the concentration of carbon dioxide in the atmosphere.

[0043] <Additives> Figure 5 shows a schematic diagram of an example in which a substance having voids 304 (hereinafter also referred to as "additive 300") has a void ratio of 5% or more and less than 50%, and there are parts in the voids 304 where the concentration of carbon dioxide is higher than the concentration of carbon dioxide in the atmosphere. Here, the term "substance" is not intended to be composed of a single material, but may be, for example, a combination of calcium-derived materials, or a combination of calcium-derived materials and aggregates used in concrete. Furthermore, any porous material such as zeolite that can be added to concrete is a substance to which the present invention can be applied and can be used as an additive.

[0044] <Porosity> In this invention, the porosity can be determined by the volume of voids 304 divided by the total volume. In this invention, if the porosity is 5% or more and less than 50%, a remarkable effect can be obtained compared to the prior art, but this does not mean that implementation in a range of porosity outside of this range is prohibited. A person skilled in the art will easily understand from the specification or drawings of this patent application that one embodiment of this invention will produce a remarkable effect if the porosity of the material is 5% or more and less than 50%.

[0045] <Carbon dioxide concentration> The concentration of carbon dioxide in the void 304 must be higher than the concentration of carbon dioxide in the atmosphere at the location where the substance is present. The concentration of carbon dioxide in the atmosphere is approximately 420 ppm, but since the concentration of carbon dioxide varies depending on the location and season, it is preferable that it be at least higher than 500 ppm. In the additive 300, it is preferable that carbon dioxide penetrates deep into the void 304, but it is not necessarily required that carbon dioxide penetrate deep into the void 304 of the substance. It can be said that the effects of the present invention can be achieved if the concentration of carbon dioxide in any part of the void 304 is higher than the concentration of carbon dioxide in the atmosphere.

[0046] It is preferable that the average value of the total carbon dioxide concentration in the voids 304 of the additive 300 is higher than the concentration of carbon dioxide in the atmosphere. Furthermore, it is preferable that only carbon dioxide is present in the voids 304 of the additive 300, and it is more preferable that the concentration of carbon dioxide in the voids 304 of the substance be between 900,000 ppm and 1,000,000 ppm.

[0047] <Immobilization process step S100> Figure 1 shows the flow of the immobilization process S100 for fixing carbon dioxide in additive 300. The following describes each step included in the immobilization process S100. Note that the description of each step does not define the scope of the present invention. The values ​​for temperature and pressure can be appropriately changed depending on the material and size of the object 300. Furthermore, steps not shown in Figure 1, such as cleaning the object 300 or humidity control, may also be included.

[0048] <Heating process step S110> The heating step S110 is a process in which the processing chamber 222 of the processing apparatus is heated by a heating device, thereby heating the additive 300, such as concrete fragments and aggregates obtained by crushing waste concrete. The heating step S110 has the effect of expanding the air present in the voids 304 of the additive 300, making it easier for the air to be released from the voids 304 of the additive 300. Heating the additive 300 before the depressurization step S120, which will be described later, has a synergistic effect that allows the depressurization step S120 to be performed more effectively.

[0049] In the heating step S110, the temperature of the additive 300 is increased. It is preferable that the surface temperature of the additive 300 be 25°C or higher. A more preferable surface temperature of the additive 300 is in the range of 100°C to less than 200°C. A more preferable temperature is 100°C to less than 120°C. Furthermore, by increasing the temperature in the center of the additive 300, it is possible to maintain a high temperature of the additive 300. Therefore, even if the temperature of the additive 300 reaches the target temperature, by continuing to heat the additive 300, the interior of the additive 300 can also be heated.

[0050] The heating device used in the heating process step S110 may be an electric heating device or a device that obtains heat by combustion. When a combustion device is used as the heating device, the carbon dioxide produced by combustion can be recovered and the carbon dioxide produced by incineration can be used in the carbon dioxide supply process step S130 described later, thereby reducing the overall release of carbon dioxide into the atmosphere.

[0051] <Depressurization process step S120> The depressurization step S120 is a process of reducing the pressure in the processing chamber 222 of the processing apparatus to discharge the air present in the voids 304 of the additive 300.

[0052] Figure 4 shows a schematic diagram of the depressurization system for depressurization step S120. The processing chamber 222 is connected to an on / off valve 219, a low-pressure fine adjustment valve 215, a low-pressure coarse adjustment valve 217, and a vacuum pump 220. The pressure in the processing chamber 222 of the processing apparatus can be adjusted by adjusting the opening and closing of each valve and the operation of the vacuum pump 220.

[0053] In the depressurization step S120, the pressure in the processing chamber 222 of the processing apparatus can be selected from the range of low vacuum, medium vacuum, and high vacuum. To obtain a more effective result, it is preferable to select high vacuum, but medium vacuum or low vacuum may also be used.

[0054] The depressurization step S120 may be performed for a period of 1 minute or more but less than 120 minutes. More preferably, it is performed for a period of 45 minutes or more but less than 90 minutes. When the depressurization step S120 is in operation, it is preferable to operate the heating device that operates in the heating step S110. In the depressurization step S120, it is preferable that the temperature inside the processing chamber 222 is 25°C or higher. A more preferable temperature inside the processing chamber 222 is 100°C or more but less than 200°C. An even more preferable temperature is 100°C or more but less than 120°C.

[0055] When the pressure inside the processing chamber 222 is reduced in the depressurization step S120, the temperature inside the processing chamber 222 decreases. However, by operating the heating device to maintain the temperature inside the processing chamber 222 at a desired temperature, the air present in the voids 304 of the additive 300 expands, and the vacuum pump 220 makes it easier to expel the air present in the voids 304 of the additive 300.

[0056] <Carbon dioxide supply process step 130> The carbon dioxide supply step 130 is a step in which carbon dioxide is supplied into the processing chamber 222 of the processing apparatus. The carbon dioxide supply step 130 is performed after the depressurization step S120. By performing the carbon dioxide supply step 130 after the depressurization step S120, carbon dioxide can be efficiently supplied to the voids 304 of the additive 300 where the air concentration is low.

[0057] Figure 4 shows a schematic diagram of the carbon dioxide supply system for carbon dioxide supply process step 130. The processing chamber 222 is connected to an on / off valve 219, a high / low pressure fine adjustment valve 215, a high pressure coarse adjustment valve 211, and a gas supply device 100. By adjusting the opening and closing of each valve and the gas supply device 100, carbon dioxide can be supplied into the processing chamber 222 of the processing apparatus while adjusting the pressure inside the processing chamber. The pressure inside the processing chamber 222 can be detected by a pressure gauge 221.

[0058] In the embodiment of the carbon dioxide supply process shown in Figure 4, a gas cylinder 110 is used as the gas supply device 100. However, the gas supply device 100 is not limited to a gas cylinder 110. It may be configured to supply carbon dioxide directly from the atmosphere, or to generate carbon dioxide within the processing chamber 222 of the processing apparatus, for example, by a chemical reaction.

[0059] In the carbon dioxide supply process step 130, it is preferable that the carbon dioxide supplied into the processing chamber 222 of the processing apparatus is configured not to leak out of the processing chamber 222 to the outside. By configuring the apparatus so that the carbon dioxide supplied into the processing chamber 222 does not leak out to the outside, the pressure inside the processing chamber 222 increases, and carbon dioxide can be efficiently supplied to the void 304 of the additive 300.

[0060] <Cooling process step S140> The cooling step S140 is a step of cooling the additive 300. In the cooling step S140, it is preferable that the temperature of the additive 300 be 25°C or lower. If heating in the heating step S110 is stopped, the temperature of the additive 300 will decrease over time, but the additive 300 may also be actively cooled by a cooling means (not shown).

[0061] <Pressurization process step S150> The pressurization step S150 is a process of increasing the pressure inside the processing chamber 222 so that carbon dioxide can enter the voids 304 of the additive 300. The pressurization step S150 can also be performed by the carbon dioxide supply step 130. By supplying carbon dioxide into the processing chamber 222 at a high pressure, the pressure inside the processing chamber 222 increases, allowing carbon dioxide to enter the voids 304 of the additive 300 and continuously supply carbon dioxide into the processing chamber 222.

[0062] Figure 4 shows a schematic diagram of the carbon dioxide supply system for the pressurization process step S150. The processing chamber 222 is connected to an on / off valve 219, a high / low pressure fine adjustment valve 215, a high pressure coarse adjustment valve 211, and a gas supply device 100. By adjusting the opening and closing of each valve and the gas supply device 100, carbon dioxide is supplied into the processing chamber 222 of the processing apparatus, and the pressure inside the processing chamber 222 can be increased while adjusting it. The pressure inside the processing chamber 222 can be measured by connecting a pressure gauge 221.

[0063] The pressure in the pressurization step S150 can be increased by supplying carbon dioxide from the gas cylinder 110, within the range of 0.001 MPa to 12 MPa based on the cylinder pressure. The pressurization time can be from 1 minute to 1 hour.

[0064] When carbon dioxide is supplied from a gas cylinder 110 and the pressure in the processing chamber 222 is increased by the supply of carbon dioxide, the pressurization time can be set to 1 hour when the cylinder pressure is 0.001 MPa. When the cylinder pressure is 12 MPa, the pressurization time can be set to 1 minute. When the cylinder pressure is higher than 0.001 MPa, the processing time can be shortened to a time shorter than 1 hour, and the pressurization time can be shortened to a range of up to 1 minute depending on the cylinder pressure up to 12 MPa. When the cylinder pressure is 0.1 MPa, pressurizing for 1 hour may be considered appropriate.

[0065] The cylinder pressure and pressurization time can be appropriately selected depending on the size and porosity of the additive 300. To produce homogeneous additive 300, pre-sorting the additive 300 according to its size, porosity, material, etc., allows for the production of high-quality additive 300 by using appropriate cylinder pressure and pressurization time.

[0066] In the embodiment shown in Figure 1, the depressurization step S120 and the pressurization step S150 are performed once, but the depressurization step S120 and the pressurization step S150 may be performed multiple times. By performing the depressurization step S120 and the pressurization step S150 alternately multiple times, a high concentration of carbon dioxide can be introduced into the voids 304 of the additive 300. Preferably, by repeating the depressurization step S120 and the pressurization step S150 three times, a high concentration of carbon dioxide can be introduced into the voids 304 of the additive 300.

[0067] <How to use concrete additive 300> Figure 2 shows the flow of creating additive 300 from building materials and adding it to concrete material 314 to make building materials. Figure 3 shows the flow of the crushing process in which concrete is crushed.

[0068] When demolishing reinforced concrete buildings and other structures, concrete waste (also called "waste concrete") is generated. The generated waste concrete may be treated as concrete blocks from which reinforcing steel, admixtures, aggregates, etc. have been removed. Due to aging, part or all of the surface of the waste concrete is oxidized.

[0069] <Grinding process S210> Figure 2 shows the grinding process S210. The concrete blocks obtained from the demolition work are crushed using a concrete crushing device at the demolition site or an intermediate processing plant. The crushing process S210 may be a single crushing process, or it may be crushed using multiple crushing processes S213, S217.

[0070] When employing multiple crushing processes S213 and S217, the process may include a primary crushing process S213 for coarsely crushing the concrete mass and a sieving and separation process 215 for sieving and separating the coarsely crushed concrete pieces.

[0071] The waste concrete sieved in the sieving and separation step S215 may be further crushed in the secondary crushing step S217 to obtain a finer form. The waste concrete fragments crushed in the secondary crushing step S217 may be further sieved in the sieving and separation step S218.

[0072] <Primary grinding process S213> Concrete blocks generated from the demolition of reinforced concrete buildings are pre-treated to separate them from the attached reinforcing steel and break them into smaller pieces. These blocks, originally measuring approximately 200-400 mm in size, are then transported to intermediate processing plants. At these plants, they undergo a primary crushing process, where they are coarsely crushed to a size of approximately 150 mm from their original dimensions. Jaw crushers and similar equipment are used for this primary crushing.

[0073] <Secondary grinding process S217> In the secondary crushing process, waste concrete is crushed using an impact crusher and various known crushers and grinders, and recycled aggregate is produced. This recycled aggregate can then be processed through a classifier to obtain recycled aggregate (recycled coarse aggregate, recycled fine aggregate) of a predetermined standard.

[0074] The waste concrete that has undergone the crushing process S210 may be further processed into a fine powder by a fine powdering process. The waste concrete, after the fine powdering process, has a specific surface area of ​​1,000 to 8,000 cm². 2 It may be processed in such a way. Also, the specific surface area of ​​the waste concrete powder may be increased to 3,000 to 4,000 cm². 2 It is preferable that the waste concrete powder be processed in such a way. By making the specific surface area of ​​the waste concrete powder fall within a predetermined range, the degree of oxidation of the waste concrete powder becomes uniform, and appropriate neutralization treatment can be performed.

[0075] <Sieving and separation process S215, S218> In the sieving and separation steps S215 and S218, the sieve residue may be crushed, ground, and classified to separate and recover coarse aggregate, fine aggregate, and waste concrete fine powder. The sieve size in the sieving and separation step may be selected from a range of 3 mm or more and less than 20 mm. Preferably, the sieve size can be 10 mm.

[0076] The waste concrete powder sieved in the sieving and separation steps S215 and S218 forms aggregates under appropriate conditions, and carbon dioxide is fixed in the immobilization step S100 according to those conditions.

[0077] In the immobilization process S100, carbon dioxide is immobilized as described above. The waste concrete from which carbon dioxide has been immobilized can be used as additive 300. <Mixing process> During the immobilization process, carbon dioxide is fixed, and the carbon dioxide-carrying additive 300 can be used as a concrete additive 300 by mixing it together with cement and aggregate in the concrete manufacturing process.

[0078] When not being used as a concrete additive, the concrete additive 300 can maintain its function as a concrete additive for a long period of time by being stored in a film that does not allow carbon dioxide to pass through.

[0079] Figure 5 shows a schematic diagram of additive 300 in a state where carbon dioxide has been fixed. Figure 6 shows a magnified view of the main part of Figure 5. From Figures 5 and 6, it can be seen that the surface of additive 300 and the surface of the void 304 are undergoing a neutralization reaction.

[0080] Figure 7 shows the initial state when the additive is mixed into the concrete material 314. The additive 300 has a carbonation reaction area 302 on its surface and around the voids 304, but the other concrete materials 314 do not have a carbonation reaction area 302.

[0081] Figure 8 shows the state of concrete material 314 after an additive has been mixed in and a predetermined time has elapsed. Carbon dioxide supported in the voids 304 of additive 300 flows out from the voids 304 to the outside. The carbon dioxide that has flowed out to the outside comes into contact with other concrete material 314 and undergoes a carbonation reaction, resulting in the presence of a carbonation reaction area 302.

[0082] In the schematic diagrams of the additive 300 shown in Figures 7 and 8, the void 304 is depicted as a single void. However, in reality, the additive 300 contains numerous voids 304, allowing for the formation of a broad neutralization reaction portion 302 on the surface of the additive 300.

[0083] It is understood that when it is desired to support a specific gas in the voids of a material with a high porosity, this can be achieved by applying and removing pressure in an atmosphere of that specific gas. Through this invention, it can be understood that this method is applicable not only to the field of architecture but also to the food and medical fields. [Explanation of symbols]

[0084] 10 ... Carbon dioxide enrichment device 100... Gas supply device 110... Gas cylinder 211... High-pressure coarse adjustment valve 213... High-pressure fine adjustment valve 215... Low-pressure fine adjustment valve 217... Low-pressure coarse adjustment valve 219... On / off valve 220... Vacuum pump 221... Pressure gauge 222... Processing Room 300... Additive (target substance) 302...Neutralization reaction portion 304...Void 310…Carbon dioxide part 312...Air part 314…Concrete materials 316…boundary

Claims

1. In a material having voids, The porosity of the aforementioned void is 5% or more and less than 50%. There are parts of the aforementioned void where the concentration of carbon dioxide is higher than the concentration of carbon dioxide in the atmosphere. A substance that has voids.

2. In a material having voids, The porosity of the aforementioned void is 5% or more and less than 50%. There are parts in the aforementioned void where the concentration of carbon dioxide is higher than the concentration of carbon dioxide in the atmosphere. A portion of the aforementioned substance contains calcium carbonate. Substances for building materials.

3. In a material having voids, The porosity of the aforementioned void is 5% or more and less than 50%. There are parts in the aforementioned void where the concentration of carbon dioxide is higher than the concentration of carbon dioxide in the atmosphere. A portion of the aforementioned substance contains calcium oxide. Substances for building materials.

4. In a material having voids, The porosity of the aforementioned void is 5% or more and less than 50%. There are parts in the aforementioned void where the concentration of carbon dioxide is higher than the concentration of carbon dioxide in the atmosphere. A portion of the aforementioned substance includes calcium carbonate and calcium oxide. Building materials.

5. In concrete additives having voids, The porosity of the aforementioned void is 5% or more and less than 50%. There are parts in the aforementioned void where the concentration of carbon dioxide is higher than the concentration of carbon dioxide in the atmosphere. A portion of the aforementioned concrete additive includes calcium carbonate and calcium oxide. Concrete additive.

6. In a method for using concrete additives containing voids, The porosity of the aforementioned void is 5% or more and less than 50%. There are parts in the aforementioned void where the concentration of carbon dioxide is higher than the concentration of carbon dioxide in the atmosphere. A portion of the aforementioned concrete additive includes calcium carbonate and calcium oxide. The concrete additive is mixed with the concrete building material while the concentration of carbon dioxide in the voids is higher than the concentration of carbon dioxide in the atmosphere, thereby promoting at least one of the carbonation or hydration reaction of the concrete building material. Instructions for using concrete additives.

7. The carbon dioxide concentration in the aforementioned void is 500,000 ppm or higher. The substance according to claims 1 to 3.

8. By placing a material having voids with a porosity of 5% or more and less than 50% in a space where the concentration of carbon dioxide is higher than the concentration of carbon dioxide in the atmosphere, and then reducing and increasing the pressure in the space, the concentration of carbon dioxide in the voids of the material is increased. A method for producing a substance having voids.

9. By placing a material having voids with a porosity of 5% or more and less than 50% in a space where the concentration of carbon dioxide is higher than the concentration of carbon dioxide in the atmosphere, and repeatedly reducing and increasing the pressure in the space, the concentration of carbon dioxide in the voids of the material is increased. A method for producing a substance having voids.

10. A processing apparatus equipped with a processing chamber in which a substance can be placed, A carbon dioxide supply device capable of supplying carbon dioxide to the aforementioned processing device, A pressure reducing device that can reduce the pressure in the processing chamber of the aforementioned processing apparatus, A pressurizing device that can increase the pressure in the processing chamber of the aforementioned processing apparatus, Equipped with, A depressurization step is performed by operating the depressurization device while a substance with a porosity of 5% or more and less than 50% is placed in the processing chamber of the apparatus, A carbon dioxide supply step involves operating the carbon dioxide supply device with the substance placed in the processing chamber of the apparatus, A pressurizing step in which the pressurizing device is operated with the substance placed in the processing chamber of the apparatus, By doing so, carbon dioxide is enriched in the voids 304 of the material. Carbon dioxide enrichment device.

11. A processing apparatus capable of placing a substance inside, A carbon dioxide supply device capable of supplying carbon dioxide to the aforementioned processing device, A pressure reducing device that can reduce the pressure in the processing chamber of the aforementioned processing apparatus, A pressurizing device that can increase the pressure in the processing chamber of the aforementioned processing apparatus, Equipped with, A depressurization step is performed by placing a substance with a porosity of 5% or more and less than 50% in the processing chamber of the apparatus, and operating the depressurization device while the temperature of the processing chamber of the apparatus is set to 25°C or higher. A carbon dioxide supply step involves operating the carbon dioxide supply device with the substance placed in the processing chamber of the apparatus, A pressurizing step in which the pressurizing device is operated with the substance placed in the processing chamber of the apparatus, By doing so, carbon dioxide is enriched in the voids of the aforementioned material. Carbon dioxide enrichment device.

12. A processing apparatus capable of placing a substance inside, A carbon dioxide supply device capable of supplying carbon dioxide to the aforementioned processing device, A pressure reducing device that can reduce the pressure in the processing chamber of the aforementioned processing apparatus, Equipped with, A depressurization step is performed by placing a substance with a porosity of 5% or more and less than 50% in the processing chamber of the apparatus, and operating the depressurization device while the temperature of the processing chamber 222 of the apparatus is set to 25°C or higher. A carbon dioxide supply step in which the carbon dioxide supply device is operated while the substance is placed in the processing chamber of the processing apparatus, thereby increasing the pressure in the processing chamber of the processing apparatus, By doing so, carbon dioxide is enriched into the voids of a material having voids 304 with a porosity of 5% or more and less than 50%. Carbon dioxide enrichment device.

13. A processing apparatus capable of placing a substance inside, A carbon dioxide supply device capable of supplying carbon dioxide to the aforementioned processing device, A pressure reducing device that can reduce the pressure in the processing chamber of the aforementioned processing apparatus, Equipped with, A depressurization step is performed by placing a substance with a porosity of 5% or more and less than 50% in the processing chamber of the apparatus, and operating the depressurization device while the temperature of the processing chamber of the apparatus is set to 100°C or higher. A carbon dioxide supply step is to place a substance with a porosity of 5% or more and less than 50% in the processing chamber of the apparatus, and increase the pressure in the processing chamber of the apparatus by operating the carbon dioxide supply device while the temperature of the processing chamber of the apparatus is 25°C or lower. By doing so, carbon dioxide is enriched in the voids of the aforementioned material. Carbon dioxide enrichment device.

14. A processing apparatus capable of placing a substance inside, A carbon dioxide supply device capable of supplying carbon dioxide to the aforementioned processing device, A pressure reducing device that can reduce the pressure in the processing chamber of the aforementioned processing apparatus, Equipped with, A depressurization step is performed by placing a substance with a porosity of 5% or more and less than 50% in the processing chamber of the apparatus, and operating the depressurization device while the temperature of the processing chamber of the apparatus is in the range of 100°C or more and less than 200°C. A carbon dioxide supply step is to place the substance in the processing chamber of the processing apparatus and increase the pressure in the processing chamber 222 of the processing apparatus by operating the carbon dioxide supply device while the temperature of the processing chamber 222 of the processing apparatus is 25°C or lower, By doing so, carbon dioxide is enriched in the voids of the aforementioned material. Carbon dioxide enrichment device.

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