Method and apparatus for binding carbon dioxide, product obtained and use thereof

Abstract

The present disclosure relates to a method of improving gas permeability, the method comprising: placing one or more porous materials in at least one of two interconnected spaces; adding carbon dioxide gas, and performing pressure fluctuation on the porous material. According to one embodiment of the present disclosure, pressure fluctuations are controlled by a flow regulator and a motor component connected to spaces connected to each other, the pressure difference of the pressure fluctuations being 0.5-2 kPa. The present disclosure also relates to a device for incorporating carbon dioxide into a porous mass, a product obtainable by the method of the present disclosure and uses of the product.

Description

Technical Field

[0001] The present disclosure relates to a method for improving gas permeability, wherein one or more porous objects are placed in at least one of two interconnected spaces, carbon dioxide gas is added, and pressure fluctuations are applied to the porous objects. More specifically, the present disclosure relates to using pressure fluctuations to improve gas permeability to the porous objects. The pressure fluctuations can be controlled by a flow regulator and a motor component connected to the interconnected spaces. The present disclosure also relates to an apparatus for incorporating carbon dioxide into a porous object, a product obtainable by the method of the present disclosure, and the use of the product. Background Art

[0002] Greenhouse gases have profound impacts on the environment and health. Climate change is the term used to describe the complex changes driven by greenhouse gas concentrations that are currently affecting our planet's weather and climate systems. Climate change includes not only the increase in average temperatures known as global warming, but also extreme weather events, rising sea levels, disruptions to food supplies, increased wildfires, changes in wildlife populations, and more. Carbon dioxide is the most abundant greenhouse gas emitted into the atmosphere.

[0003] The world’s cement production and concrete industry has been recognized as generating a significant portion of global CO2 emissions. These emissions come from the calcination process and energy use.

[0004] The captured CO2 can be used to enhance oil recovery, make fuels, building materials, etc., or stored in underground geological formations. Low carbon footprint concrete products have been developed by replacing cement with alternative binders, using geopolymers and low amounts of binders in concrete, and using CO2 to cure concrete. However, none of these methods alone can produce carbon-negative concrete if the emissions from the raw materials and their processing are taken into account.

[0005] WO 2021105726 A1 discloses a concrete preparation system in which carbon dioxide is mixed with a mixture of aggregate, cement and water in a pretreatment chamber before casting and curing the concrete.

[0006] Although climate change and the greenhouse effect are the subject of constant innovation in products and processes in this field, there is still a pressing need for improvement. Summary of the invention

[0007] An object of the present disclosure is to provide a method and an apparatus for implementing the method to improve the permeability of carbon dioxide to a porous material such as a porous object, a porous part or a porous member.

[0008] The objects of the present disclosure are achieved by the methods, devices and uses described in the independent claims. Preferred embodiments of the present disclosure are disclosed in the dependent claims.

[0009] The present disclosure is based on the idea of ​​changing the gas in the pores of a porous object by causing pressure changes in the space where the porous object is placed. The pressure changes will cause the gas to repeatedly flow into or out of the pores of the porous object, thereby effectively changing the gas in the pores of the object, just like "artificial respiration".

[0010] Since the method of the present disclosure can improve the gas permeability to porous materials, one advantage of the method, device and use of the present disclosure is that a large amount of carbon dioxide can be absorbed in the product, thereby reducing the carbon footprint of the product, or even making the product have a negative carbon footprint.

[0011] Another advantage of the present disclosure is that the pressure fluctuations are small, thereby facilitating industrial use. The pressure is generally within the normal atmospheric pressure range, between the lowest and highest measurable sea level pressures.

[0012] In the method of the present disclosure, further advantages are obtained when the method is used to solidify and optionally dry concrete or concrete-like articles (e.g., precast concrete or concrete-like articles) using carbon dioxide (carbon solidification). Due to the improved permeability of the gas to the porous material, more carbonate-based minerals are formed, thereby improving the mechanical properties of the carbonized product of the concrete or concrete-like. In the method of the present disclosure, due to the poor permeability of carbon dioxide to the porous material, the formation of carbonate-based minerals is not restricted, so the degree of carbonization is higher than that of existing carbon solidification processes.

[0013] Compared with conventional methods, the processing time required to obtain higher CO2 absorption and / or higher carbonation degree using the method of the present disclosure is generally shorter. For example, the curing time can be greatly shortened compared with conventional concrete technology. Using the method of the present disclosure, carbonate minerals can generally be formed in 24 hours or less, so the method is suitable for manufacturing concrete and concrete or concrete-like products under industrial conditions.

[0014] Advantageously, by the method of the present disclosure, the amount of CO2 absorbed, i.e. the amount of CO2 bound to the product, is greater than the carbon footprint of the raw materials, transport and production (produced according to the product stage of module A1-3 of EN 15804+A1), so that, for example, negative carbon concrete or concrete-like products can be produced. Using the method of the present disclosure, the amount of CO2 absorbed in the raw materials, calculated as the mass of CO2 bound per unit mass of raw materials, is typically greater than 10 wt.%, preferably greater than 20 wt.%, and more preferably greater than 30 wt.%. The CO2 absorption of other known CO2 solidification methods typically reaches 4-10% (mass of bound CO2 / mass of binder and / or raw materials). The CO2 absorption of the method of the present disclosure allows the realization of negative carbon concrete or concrete-like products, in which the CO2 footprint of all raw materials, their transportation and processing processes is less than the amount of CO2 bound in the product. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The present disclosure will be described in more detail below through preferred embodiments with reference to the accompanying drawings, wherein

[0016] Figure 1 A schematic diagram of one embodiment of the present disclosure is shown;

[0017] Figure 2 An example of performing pressure fluctuations according to the method of the present disclosure is shown; and

[0018] Figure 3 shows the results of mechanical strength compared to a reference sample. DETAILED DESCRIPTION

[0019] The present disclosure relates to a method for improving gas permeability, the method comprising: placing one or more porous objects in at least one of two interconnected spaces; adding carbon dioxide gas, and subjecting the porous objects to pressure fluctuations. Preferably, the pressure difference of the pressure fluctuation is less than 2 kPa.

[0020] According to one embodiment of the present disclosure, pressure fluctuations are controlled by a flow regulator and a motor component connected to the interconnected spaces.

[0021] The present disclosure also relates to a device for incorporating carbon dioxide into a porous object, preferably for carbonization of the porous object, wherein the device comprises a first space (A) connected to an inlet of a motor component (1) and a second space (B) connected to an outlet of the motor component, and at least one flow regulator (2) between the first space (A) and the second space (B).

[0022] The present disclosure also relates to a product obtainable by the process of the present disclosure, preferably a concrete or concrete-like product, and the use of the product as a building material, preferably for the production of concrete or concrete-like products, more preferably for the production of carbides, most preferably for the production of precast carbides, and the use of the process and the product in the medical field (e.g. for granule synthesis), in the steel industry and / or in the construction industry (preferably in the construction industry), more preferably for the production of concrete or concrete-like products in a precast concrete plant and / or for the curing of concrete or concrete-like products, preferably precast concrete or concrete-like products.

[0023] As used herein, the term "porous" refers to a material that has voids and is permeable to external influences, such that, for example, air, water or other gases and fluids can flow within the material. In a porous material, the main framework of atoms that make up the solid structure does not occupy the voids.

[0024] In the embodiments of the present disclosure, the space of the present disclosure is generally at least two interconnected enclosed spaces, such as containers or chambers, or a partitioned space divided into a plurality of compartments. Typically, the space is sealed, substantially airtight, so that the carbon dioxide gas does not mix with the outside air to any necessary extent. Preferably, the space is sealed with polyvinyl chloride (PVC), more preferably with a density of at least 630 g / m 2 PVC fabric seal.

[0025] In an embodiment of the present disclosure, the airflow between space A and space B is generated by a motor component and controlled by a flow regulator that controls the airflow between space A and space B. Relative to the initial state pressure, inhibiting the flow of gas produces an overpressure into space A and a negative pressure into space B. Returning the flow regulator to the initial position will restore the initial pressure state. Reversing the direction of the airflow will produce a negative pressure into space A and an overpressure into space B relative to the initial state pressure. Regulating the airflow is repeated continuously for 2-48 hours, preferably 12-48 hours. The treatment time starts from the time the article is exposed to carbon dioxide gas and continues until the exposure to carbon dioxide gas stops, and is generally 2-48 hours, preferably 12-48 hours or 4-36 hours, more preferably 4-30 hours, and most preferably 4-24 hours, including treatment times of any two of the following or between any two of the following: 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47 and 48. The fluctuation cycle (e.g., from the highest pressure to the lowest pressure and then back to the highest pressure) generally occurs between 1 time / minute and 1 time / hour, preferably between 1 time / hour and 60 times / hour, and more preferably between 6 times / hour and 12 times / hour. During the pressure fluctuation, the temperature of space (A) and / or space (B) is generally 20-80°C, preferably 40-60°C. In the method and / or device of the present disclosure, the temperature and relative humidity of space (A) and / or space (B) are generally monitored and / or controlled by a process control system.

[0026] The relative humidity of space (A) and / or space (B) is generally maintained at 10-90%, preferably at 40-70%, more preferably at 40-60%, and most preferably at 55-60%. In an embodiment of the present disclosure, cement and cement-like items are cured at a relative humidity of 40-70%, more preferably 55-60% or 40-55%, because curing according to the method of the present disclosure does not consume water. In an embodiment of the present disclosure, unlike conventional processes, the water (or moisture) that preferably fills the pores of the porous object is generally less. In conventional curing processes, post-treatment of the cast product is typically accomplished by wetting, using a post-treatment agent, leaving the mold in place, using insulating materials, plastic coverings, or by other methods to retain moisture in the concrete.

[0027] In the embodiments of the present disclosure, the flow regulator is generally a valve, preferably a ball valve, a butterfly valve, a check valve, a gate valve, a knife gate valve, a stop valve, a needle valve, a pinch valve, a plug valve or a pressure reducing valve, more preferably a butterfly valve.

[0028] In the embodiment of the present disclosure, the motor component is a component that generates airflow between the space A and the space B, and is preferably a blower or a fan, and more preferably a fan.

[0029] In an embodiment of the present disclosure, carbon dioxide gas is generally a gas containing carbon dioxide, preferably carbon dioxide gas contains 1-100% carbon dioxide, preferably 1-99% carbon dioxide, more preferably 30-90% carbon dioxide, more preferably 40-70% carbon dioxide. In some embodiments of the present disclosure, carbon dioxide gas is purified carbon dioxide gas, containing more than 99%, preferably 80-100%, more preferably 85-99%, most preferably 85-95% carbon dioxide, that is, carbon dioxide gas concentrated to a preferred degree by a gas concentration method or membrane such as absorption or adsorption. In a preferred embodiment of the present disclosure, carbon dioxide gas contains 1-100% carbon dioxide, preferably 30-90% carbon dioxide, more preferably 40-70% carbon dioxide, or generally 20-30% or 85-95% carbon dioxide, and is obtained from an industrial side stream or by-product, and the preferred source of carbon dioxide gas is a power plant or factory flue gas, a waste gas produced by a biogas plant or ethanol fermentation, or a refinery tail gas. The method or device of the present disclosure is optionally integrated into a carbon dioxide gas source production process, such as a direct material flow device through the same plant area.

[0030] In an embodiment of the present disclosure, carbon dioxide gas is preferably added before the pressure fluctuation begins. Carbon dioxide gas can be added all at once, but is usually added in batches, preferably in the first batch at the beginning, and then in other batches. Typically, the amount of carbon dioxide gas in the first batch is larger than that in other batches, and carbon dioxide gas is usually added when needed, for example, when the carbon dioxide content is measured to be lower than a certain required level, and the carbon dioxide content can be measured by appropriate means during the pressure fluctuation, such as by being part of a process control system. The higher the carbon dioxide content, the faster the carbonization rate. The amount of carbon dioxide in space A and / or space B is at most substantially the same as the amount of carbon dioxide in the carbon dioxide gas, which means that the added carbon dioxide gas replaces the air in space A and / or space B. Therefore, the preferred level of carbon dioxide in the process corresponds to the amount of carbon dioxide in the carbon dioxide gas. Typically, carbon dioxide gas is added to space A and / or space B through at least one inlet connected to one or two spaces, but carbon dioxide can also be added at any position in the device of the present disclosure. Typically, carbon dioxide gas is added through an inlet for providing carbon dioxide gas, and air is usually discharged through an outlet for discharging air.

[0031] According to an embodiment of the present disclosure, the difference between the initial pressure and the maximum pressure of the first space and / or the second space and the difference between the initial pressure and the minimum pressure are generally lower than 2 kPa, preferably about 1 kPa. The minimum pressure and the maximum pressure are generally between the lowest measurable sea level pressure of about 87 kPa and the highest measurable sea level pressure of about 109 kPa. Compared with the initial pressure at the beginning of the test, the pressure difference during the pressure fluctuation is generally less than 2 kPa, preferably 0.5-2 kPa, or 0.5-1.8 kPa, more preferably 0.8-1.5 kPa, and most preferably 0.9-1.1 kPa, and the lowest pressure and the highest pressure include any one of the following atmospheric pressures: 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 100, 101, 101.325, 102, 103, 104, 105, 106, 107, 108 and 109 kPa, and the pressure difference is relative to the initial state pressure. Preferably, the pressure fluctuation varies between slightly higher and slightly lower than the initial pressure.

[0032] In an embodiment of the present disclosure, the porous object is a three-dimensional object, component or structure. Typically, the porous object is a precast concrete or concrete-like object, such as a hollow slab, brick, block, ashlar, stone or component.

[0033] Typically, precast articles are prepared by conventional concrete techniques by mixing or stirring a mixture comprising raw materials, aggregates, water and / or binders, and then casting or extruding the mixture into concrete. The aggregates and / or binders used are typically those known in conventional concrete techniques, and the mixture is typically referred to as a raw material mixture. The raw materials may include cementitious materials and / or conventional cement. In some embodiments of the present disclosure, the raw materials are preferably solid and include or consist entirely of industrial waste, residues or side streams. Typically, the raw material comprises or is selected from slag products such as blast furnace slag, electric arc furnace slag (oxidized and reduced), ladle furnace slag, steel slag, argon oxygen decarburized slag and basic oxygen furnace slag; ash, such as municipal waste incinerator ash, cyclone dust collector and bag filter, bio-based ash, bark ash, peat ash, fly ash and slag, lignite ash, oil shale ash and boiler ash; tailings, such as mine tailings and metal tailings, such as red mud produced by alumina refining; other waste products, such as cement kiln and secondary kiln dust, inorganic construction waste and recycled concrete and any combination thereof. The particle size of the raw material is generally less than 250 μm, preferably 50-0.5 μm, which means that more than 50% of the particles have such a particle size by volume. According to embodiments of the present disclosure, the raw material itself can be used as an aggregate and / or a binder. In some embodiments, the mixture also contains an alkaline substance. The alkaline material can be a pure chemical or an industrial waste, residue or side stream, especially a waste, residue or side stream of the paper industry. The alkaline material generally comprises or consists of alkaline oxides, alkali metal and alkaline earth metal oxides, hydroxides, silicates, sulfates and / or mixtures thereof and / or aqueous solutions thereof. In an embodiment of the present disclosure, the alkaline material may comprise or be selected from NaOH, Na2O, Mg(OH)2, MgO, Ca(OH)2, CaO, KOH, K2O, green liquor residue, paper sludge and lime kiln residue and any combination thereof, preferably selected from green liquor residue, paper sludge and lime kiln residue.

[0034] In an embodiment of the present disclosure, precast concrete or concrete-like articles are cured by carbon dioxide gas, and carbonate minerals formed in the cured product can strengthen the product structure.

[0035] In the embodiments of the present disclosure, the degree of carbonization is generally more than 40% of the theoretical degree of carbonization, preferably 40-95% of the theoretical degree of carbonization, more preferably 55-85%, and most preferably 70-80%. The degree of carbonization is calculated as a percentage of the theoretical degree of carbonization to the total dry weight of the carbonizable material in the raw material mixture. For example, the theoretical value of calcium oxide is 79% (wt.) of the total dry weight.

[0036] Mechanical strength properties are typically measured by SFS-EN 12350, SFS-EN 12504 and / or SFS-EN 13791. In a preferred embodiment of the present disclosure, the mix is ​​cured until the desired CO2 absorption of the product is observed. The CO2 absorption amount refers to the mass of CO2 combined per unit mass of raw material, preferably 10-100wt.%, more preferably 20-45wt.%, most preferably 30-45wt.%, including absorption amounts between any of the following values: 4wt.%, 5wt.%, 6wt.%, 7wt.%, 8wt.%, 9wt.%, 10wt.%, 11wt.%, 12wt.%, 13wt.%, 14wt.%, 15wt.%, 20wt.%, 25wt.%, 30wt.%, 35wt.%, 40wt.%, 45wt.%, 50wt.%, 55wt.%, 60wt.%, 65wt.%, 70wt.%, 75wt.%, 80wt.%, 85wt.%, 90wt.%, 95wt.% and 100wt.%. Typically, the CO2 absorption is more than 10 wt.%, preferably more than 20 wt.%, and more preferably more than 30 wt.%, calculated as the mass of CO2 per unit mass of raw materials. This absorption may be higher than the amount of CO2 released during the production of raw materials, during the use of the method of the present disclosure, and / or during the manufacture of concrete or similar concrete objects, so the carbon footprint may be negative.

[0037] Example

[0038] Example 1

[0039] The test samples were prepared to meet the concrete strength requirements for building structures. 3 Portland cement, 140kg / m 3 Water, 2080kg / m 3 The test specimens were manufactured using standard precast concrete production machinery.

[0040] Example 2

[0041] The test sample of Example 1 was placed Figure 1 In the first space (A) of the device shown. Space A is connected to the inlet of the centrifugal fan, and the second space (B) is connected to the outlet of the blower. A butterfly valve is used as a flow regulator (2) between the first space (A) and the second space (B). Carbon dioxide gas (containing 100% carbon dioxide) is introduced into the process through a magnetic valve, and air is discharged through another valve.

[0042] The gas flowing from space A to space B is restricted by the butterfly valve, which generates a negative pressure of 0.5 kPa and an overpressure of 0.5 kPa in space A relative to the initial state of 98.5 kPa ( Figure 2 ). The flow regulator was returned to its initial position to restore the initial pressure state, and the flow adjustment was repeated. The pressure varied between 99-97 kPa, and the pressure difference was less than about 1.5 kPa compared to the initial pressure. The treatment time was 24 hours from the time the part was exposed to the CO2 gas until the pressure fluctuation stopped and the exposure to the CO2 gas stopped.

[0043] The compressive strength of the produced test specimens and reference specimens produced from standard precast concrete were measured. The produced test specimens were measured directly after the exposure to CO2 gas had ceased ( Figure 3A , 0 days). Figure 3A As can be seen in the figure, the compressive strength of the test sample increased by 20% compared to the reference sample. After 7 days, it increased by 22% compared to the reference sample.

[0044] Measured directly after stopping exposure to carbon dioxide gas, the test sample absorbed 2.7% of CO2 from the total dry weight, which is equivalent to 22% of the weight of the raw material. The degree of carbonization is 44% of the theoretical degree of carbonization. Due to carbonization, the carbon footprint of the test sample is reduced by 22%.

[0045] Example 3

[0046] The test samples of lightweight ashlars and wall elements were cured under conditions similar to those of Example 2. The reference samples were similar lightweight ashlars and wall elements from the same batch that were not carbonized during curing. Figure 3B It can be seen that the compressive strength of the ashlars increased by 17% compared to the reference ashlars. The degree of carbonation was 76% of the theoretical degree of carbonation and the CO2 absorbed by the test sample was 38% of the initial raw material weight. The compressive strength of the wall element increased by 28% compared to the reference wall element.

Claims

1. A method for improving gas permeability, characterized in that: The method comprises: - placing one or more porous objects in at least one of the two interconnected spaces; - Adding carbon dioxide gas; - subjecting the porous material to pressure fluctuations; Among them, the pressure difference of the pressure fluctuation is 0.5-2kPa.

2. The method according to claim 1, characterized in that: The method further includes controlling the pressure fluctuations via a flow regulator and a motor component connected to the interconnected spaces.

3. The method according to any one of the preceding claims, characterized in that The pressure difference during the pressure fluctuation is 0.8-1.5 kPa, preferably 0.9-1.1 kPa.

4. The method according to any one of the preceding claims, characterized in that The porous object is precast concrete or an object similar to precast concrete.

5. The method according to claim 4, characterized in that The precast concrete or precast concrete-like article is cured by carbon dioxide gas.

6. The method according to any one of the preceding claims, characterized in that The carbon dioxide gas contains 1-100% carbon dioxide, preferably 1-99% carbon dioxide, more preferably 30-90% carbon dioxide, more preferably 40-70% carbon dioxide, and / or the treatment time is 2-48 hours, preferably 4-36 hours, more preferably 4-30 hours, most preferably 4-24 hours.

7. The method according to any one of the preceding claims, characterized in that The carbon dioxide gas is obtained from an industrial side stream, preferably from power plant or factory flue gas or other side streams, such as waste gas from a biogas plant or ethanol fermentation or tail gas from an oil refinery.

8. The method according to any one of the preceding claims, characterized in that During the pressure fluctuation, the temperature of space (A) and / or space (B) is 20-80°C, preferably 40-60°C, and / or the relative humidity of space (A) and / or space (B) is 10%-90%, preferably 40%-70%, more preferably 40%-60%, and most preferably 55%-60%.

9. A device for incorporating carbon dioxide into a porous object, characterized in that The device comprises a first space (A) connected to the inlet of a motor component (1) and a second space (B) connected to the outlet of the motor component, and at least one flow regulator (2) between the first space (A) and the second space (B), wherein the device also comprises a process control system for monitoring and controlling the temperature and humidity in the space (A) and / or the space (B), and an inlet for providing carbon dioxide gas.

10. The device according to claim 9, characterized in that The device is integrated into the carbon dioxide gas source production process of a general plant.

11. A product obtainable by the method according to any one of claims 1 to 8, characterized in that The carbonation degree of the product is 40%-95%, more preferably 55%-85%, most preferably 70%-80% of the theoretical carbonation degree. The product is preferably concrete or a concrete-like product.

12. The product according to claim 11, characterized in that Calculated based on the mass of CO2 per unit mass of raw materials, the CO2 absorption capacity of the product is 10-100wt.%, preferably 20-45wt.%, and more preferably 30-45wt.%.

13. The method according to claims 1-8 or the device according to claims 9-10, wherein: The flow regulator is a valve, preferably a ball valve, a butterfly valve, a check valve, a gate valve, a knife gate valve, a stop valve, a needle valve, a pinch valve, a plug valve or a pressure reducing valve, more preferably a butterfly valve.

14. The method according to claims 1-8 or the device according to claims 9-10, characterized in that The motor component is a component that generates airflow between space A and space B. Preferably, the motor component is a blower or a fan, more preferably a fan.

15. Use of the method according to any one of claims 1 to 8 in the medical field, the steel industry and / or the construction industry, preferably in the construction industry for producing concrete or concrete-like products.

16. Use of the product of claim 11 or 12 as a building material, preferably for curing concrete or concrete-like products, more preferably for curing precast objects.

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