Fluidic solidified soil for trapping and immobilizing carbon dioxide and preparation method thereof
By modifying coal asphalt organic polymers, porous coal asphalt particles with high porosity and applying them to fluid-stand solidified soil, the problem of insufficient carbon dioxide capture capacity in the fluid-stand solidified soil in the prior art is solved. It achieves both efficient adsorption, environmental protection performance and engineering applications.
Patent Information
- Application Number
- CN202411583226.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-07
- Publication Date
- 2025-02-14
AI Technical Summary
The prior art is difficult to effectively improve the capacity of carbon dioxide capture and conserve by fluid solidified soil, and there are problems of environmental pollution and reaction difficult to control.
By modifying coal asphalt with organic polymers, porous coal asphalt particles with high porosity were obtained, and applied to fluid-stand solidified soil, and porous structures were formed through cross-linking and pyrolysis reactions.
The adsorption capacity of fluid solidified soil to carbon dioxide is improved, its mechanical properties and fluidity are improved, and resource recycling is realized, environmental pollution is reduced, and the entire preparation method is simple and costly.
Smart Images
Figure CN119430797A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the field of environmental engineering, and in particular to a fluidized solidified soil for capturing and storing carbon dioxide and a preparation method thereof. Background Art
[0002] With the rapid development of infrastructure construction in my country, environmental protection issues have become increasingly prominent, especially the issue of carbon dioxide emissions. Fluidized solidified soil is a geotechnical engineering material with certain strength, water stability and low permeability formed by adding curing agent, necessary water and additives to pre-treated rock or mud. It has the characteristics of flowability, controllable strength, convenient construction, and the ability to backfill small gaps. It is widely used in backfill in construction projects. Studies have found that using fluidized solidified soil for backfilling while improving its ability to capture and store carbon dioxide is not only of great significance for reducing carbon dioxide emissions and mitigating global climate change, but also has a positive impact on improving the performance and application scope of fluidized solidified soil.
[0003] In order to improve the carbon dioxide capture and storage capacity of fluidized solidified soil, researchers began to explore the possibility of introducing porous carbon materials. Porous carbon materials have excellent carbon dioxide adsorption capacity due to their high specific surface area and adjustable pore structure, and are one of the key materials in carbon dioxide capture, utilization and storage (CCUS) technology. Among the many potential porous carbon material precursors, coal tar pitch, as an industrial byproduct, has become a promising candidate material for conversion into porous carbon materials because of its low price, high yield, wide source, good fluidity, easy control of morphology and structure, high reactivity and high carbon content. Existing technologies usually use physical or chemical methods to activate and pore coal tar pitch to convert it into porous carbon materials. Although physical methods can introduce certain voids, they cannot obtain coal tar pitch with high porosity. Although chemical methods can obtain coal tar pitch with high porosity, they usually use chemical reagents such as strong acids and strong bases, which cause great environmental pollution and are difficult to control the reaction.
[0004] Therefore, it has become an urgent problem to develop an environmentally friendly, reaction-controllable and high-porosity coal tar pitch and apply it to fluidized solidified soil to achieve the material value of low-carbon, zero-carbon and negative-carbon. Summary of the invention
[0005] The purpose of the present invention is to provide a method for preparing fluidized solidified soil for capturing and storing carbon dioxide. By modifying coal tar pitch with an organic high molecular polymer to obtain porous coal tar pitch particles with high porosity and strong carbon dioxide adsorption capacity, the porous coal tar pitch particles are applied to fluidized solidified soil, which can not only improve the carbon dioxide adsorption capacity of the fluidized solidified soil, but also improve the mechanical properties and fluidity of the fluidized solidified soil to a certain extent.
[0006] In order to achieve the above object, the present invention provides a method for preparing fluidized solidified soil for capturing and storing carbon dioxide, the method comprising:
[0007] Step 1, crosslinking reaction and pyrolysis reaction of coal tar and organic polymer solution at 300-450° C. to obtain porous coal tar particles, wherein the organic polymer solution comprises at least one of polyacrylonitrile solution and polyvinyl pyrrolidone solution;
[0008] Step 2: Mix the porous coal tar particles, cement, fly ash, clay, water and high-efficiency water reducing agent, and stir to form a fluidized solidified soil for capturing and storing carbon dioxide.
[0009] Optionally, in step 1, the coal tar pitch is heated to 90°C-110°C in advance, and the organic high molecular polymer solution is heated to 50°C-70°C in advance.
[0010] Optionally, in step 1, the mass ratio of the coal tar pitch and the organic high molecular polymer solution is (0.7-1.0): (0.8-1.1), and the heating time is 1.5-2.5h.
[0011] Optionally, the particle size of the porous coal tar particles is 1.18 mm-4.75 mm, and the mass fraction of the porous coal tar particles in the fluidized solidified soil for capturing and storing carbon dioxide is 5%-40%.
[0012] Optionally, in step 2, the mass fraction of cement in the fluidized solidified soil for capturing and storing carbon dioxide is 15%-40%.
[0013] Optionally, in step 2, the mass fraction of fly ash in the fluidized solidified soil for capturing and storing carbon dioxide is 5%-20%.
[0014] Optionally, in step 2, the mass fraction of clay in the fluidized solidified soil for capturing and storing carbon dioxide is 10%-30%.
[0015] Optionally, in step 2, the mass fraction of water in the fluidized solidified soil for capturing and storing carbon dioxide is 10%-20%.
[0016] Optionally, in step 2, the high-efficiency water reducer includes any one of KSW-3 high-efficiency water reducer, ZWL-A-IX high-efficiency water reducer, and RAWY101 polycarboxylic acid high-performance water reducer, and the mass fraction of the high-efficiency water reducer in the fluidized solidified soil for capturing and storing carbon dioxide is 0.2%-0.5%.
[0017] The present invention also provides a fluidized solidified soil for capturing and storing carbon dioxide obtained by the above-mentioned preparation method.
[0018] Compared with the prior art, the technical solution of the present invention has at least the following beneficial effects:
[0019] 1) An organic polymer solution containing at least any one of polyacrylonitrile (PAN) solution and polyvinylpyrrolidone (PVP) solution has good compatibility with coal tar. After the organic polymer solution and coal tar are evenly mixed, a cross-linking reaction occurs under high temperature conditions. At the same time, the small molecule gas generated by the pyrolysis reaction of the organic polymer is evenly distributed in the liquid coal tar. As the reaction proceeds, the small molecule gas gradually evaporates. After cooling, a large number of uniform pores are formed in the coal tar to obtain porous coal tar particles, which are applied to fluidized solidified soil. The prepared fluidized solidified soil has excellent carbon dioxide capture, utilization and storage capabilities, is beneficial to reducing carbon dioxide emissions, mitigating climate change, has high environmental protection performance, and can meet the strength, durability and fluidity requirements of fluidized solidified soil in engineering applications.
[0020] 2) The industrial by-product of coal tar is used as the base material to realize the recycling of resources. Two organic polymers, PAN and PVP, are used to activate and create pores in the coal tar without the use of chemical reagents such as strong acids and alkalis, which greatly reduces pollution to the environment.
[0021] 3) The activation pore-forming reaction process is controllable, and the entire fluidized solidified soil preparation method is simple, low-cost, and has good application prospects. BRIEF DESCRIPTION OF THE DRAWINGS
[0022] Figure 1 The present invention is a flow chart of the method for preparing fluidized solidified soil.
[0023] Figure 2 It is a comparison chart of the seven-day unconfined compressive strength test of the fluidized solidified soil prepared in Examples 1-6 of the present invention.
[0024] Figure 3 This is a comparison chart of the carbon dioxide adsorption test of the fluidized solidified soil prepared in Examples 1-6 of the present invention.
[0025] Figure 4It is a comparison chart of the fluidity test of the fluidized solidified soil prepared in Examples 1-6 of the present invention. DETAILED DESCRIPTION
[0026] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.
[0027] In the description of the present invention, it should be noted that the terms "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.
[0028] As described in the background technology, fluidized solidified soil currently shows certain potential in CCUS. In order to improve the carbon dioxide capture and storage capacity of fluidized solidified soil, porous carbon materials can be introduced to enhance its adsorption capacity for carbon dioxide, thereby reducing carbon dioxide emissions and improving its environmental performance. Coal tar has the characteristics of low price, high reactivity, and high carbon content, and can be converted into porous carbon materials in a variety of ways. However, existing physical or chemical methods cannot obtain coal tar with high porosity, cause greater environmental pollution, and the reaction is difficult to control.
[0029] In order to solve the above problems, the present invention provides a novel method for preparing fluidized solidified soil, the process of which is as follows: Figure 1 As shown, the coal tar is first heated to 100°C, the PAN and PVP mixed solution is heated to 60°C, and then the heated coal tar, PAN and PVP mixed solution are evenly mixed to undergo cross-linking reaction and pyrolysis reaction at 400°C to obtain porous coal tar. The porous coal tar is then cooled, washed and sieved to obtain porous coal tar particles. Finally, the porous coal tar particles, cement, fly ash, clay, water and high-efficiency water reducer are mixed and stirred to form fluidized solidified soil. This preparation method not only improves the adsorption capacity of fluidized solidified soil for carbon dioxide, but also improves the mechanical properties and fluidity of the fluidized solidified soil to a certain extent. Specifically, the present invention provides a preparation method for fluidized solidified soil for capturing and storing carbon dioxide, the method comprising:
[0030] Step 1: Coal tar pitch and an organic high molecular polymer solution undergo crosslinking reaction and pyrolysis reaction at 300-450° C. to obtain porous coal tar pitch particles, wherein the organic high molecular polymer solution comprises at least one of a polyacrylonitrile solution and a polyvinyl pyrrolidone solution.
[0031] In this embodiment, the organic polymer solution is a mixed solution of polyacrylonitrile and polyvinyl pyrrolidone. The coal tar pitch is heated to 90°C-110°C in a high-temperature furnace in advance to make it a solid solution mixed state, and the organic polymer solution is heated to 50°C-70°C in advance. Because the two have good compatibility, it is easier to mix evenly after heating in advance to ensure full contact, creating favorable conditions for the subsequent formation of evenly distributed pores in the liquid coal tar pitch. The mass ratio of the coal tar pitch and the organic polymer solution is (0.7-1.0): (0.8-1.1), and a slightly excessive solution is more conducive to full mixing. After mixing evenly, it is placed in an electric heating tubular furnace at 300-450°C for heating activation treatment, and the heating time is 1.5-2.5h. During this time, the polyacrylonitrile and polyvinyl pyrrolidone can be completely decomposed.
[0032] The decomposition temperature of polyacrylonitrile and polyvinyl pyrrolidone is 200°C. When the temperature rises to 300°C or above, the decomposition rate of both can be increased and the reaction time can be shortened. At 300-450°C, the mixed solution of polyacrylonitrile and polyvinyl pyrrolidone undergoes a crosslinking reaction with the coal tar pitch that has changed from a solid-solution mixed state to a liquid state. At the same time, the polyacrylonitrile as an activator undergoes thermal decomposition, and the polyvinyl pyrrolidone as an activation aid also undergoes thermal decomposition. The two form a good synergistic effect to jointly produce small molecular gases such as ammonia and carbon dioxide. These small molecular gases are evenly distributed in the liquid coal tar pitch. As the reaction proceeds, the small molecular gases gradually volatilize, and more uniform pores are formed in the coal tar pitch. After cooling to room temperature, the unreacted organic polymers and impurities are removed by washing with water and ethanol to obtain a porous coal tar pitch in a solid state with high porosity. The porous coal tar pitch is then sieved to obtain porous coal tar pitch particles by sieving out a small amount of ash generated during the heating process. The porous coal tar pitch particles have a particle size of 1.18 mm to 4.75 mm. The porous coal tar pitch particles with a particle size greater than 4.75 mm can be crushed before use. If the particle size is too large, it is not conducive to sufficient mixing with other components. In addition, the temperature of heating activation should not exceed 450°C, otherwise it is easy to cause the decomposition rate to be too fast and the reaction process to be uncontrollable.
[0033] This activation process uses coal tar, an industrial by-product, as a base material, achieving the recycling of resources. Two organic polymers, polyacrylonitrile and polyvinyl pyrrolidone, are used to activate and create pores in the coal tar without the use of chemical reagents such as strong acids and alkalis, greatly reducing pollution to the environment.
[0034] Step 2: Mix the porous coal tar particles, cement, fly ash, clay, water and high-efficiency water reducing agent, and stir to form a fluidized solidified soil for capturing and storing carbon dioxide.
[0035] The porous coal tar pitch particles have a high porosity and a strong ability to adsorb carbon dioxide, which is beneficial to reducing carbon dioxide emissions and protecting the environment. However, a high content of porous coal tar pitch particles may reduce the strength, durability and fluidity of the fluidized solidified soil, so the mass fraction of the porous coal tar pitch particles in the fluidized solidified soil for capturing and storing carbon dioxide should be controlled at 5%-40%.
[0036] As the main cementitious material, cement can provide strength to the fluidized solidified soil. Increasing the cement content can improve its strength, but too high a cement content will increase the cost and may affect its fluidity. Therefore, the mass fraction of the cement in the fluidized solidified soil for capturing and storing carbon dioxide should be controlled at 15%-40%.
[0037] The addition of fly ash will slow down the hydration rate of cement and postpone the hydration heat peak. A small part of the heat that should be released at the peak has been released slowly and steadily during the time when the peak is postponed, thereby reducing the hydration heat, effectively preventing cracks caused by temperature changes, and making the performance of the fluidized solidified soil more stable. When the fly ash content is high, the cement content will decrease, resulting in a decrease in the strength of the fluidized solidified soil. In order to ensure the strength and fluidity of the fluidized solidified soil, the mass fraction of the fly ash in the fluidized solidified soil for capturing and storing carbon dioxide should be controlled at 5%-20%.
[0038] Clay contains a relatively high amount of fine particles, which can react with silicates, calcium aluminates, etc. in the fluidized solidified soil to generate products with cementing properties, thereby improving the strength and stability of the fluidized solidified soil. At the same time, the fine particles of clay can improve the flowability of the fluidized solidified soil, making it easier to flow and fill the area that needs to be filled under the action of its own weight. The mass fraction of the clay in the fluidized solidified soil for capturing and storing carbon dioxide is 10%-30%.
[0039] Water is an important component of fluidized solidified soil. It not only allows the added components to be evenly mixed, but also participates in the hydration reaction of cement and affects its fluidity. An appropriate amount of water can ensure good fluidity and strength, but too much water can cause bleeding and reduce strength. Therefore, the mass fraction of water in the fluidized solidified soil for capturing and storing carbon dioxide should be controlled at 10%-20%.
[0040] The high-efficiency water reducer can reduce the surface tension of water, improve the fluidity of the fluidized solidified soil and reduce the water consumption. The amount of the high-efficiency water reducer should be strictly controlled to avoid adverse effects on the performance of the fluidized solidified soil. In some embodiments, the high-efficiency water reducer includes any one of KSW-3 high-efficiency water reducer, ZWL-A-IX high-efficiency water reducer, and RAWY101 polycarboxylic acid high-performance water reducer. The mass fraction of the high-efficiency water reducer in the fluidized solidified soil for capturing and storing carbon dioxide is 0.2%-0.5%.
[0041] In step 2, the content ratio of each component can be adjusted so that the carbon dioxide capture and storage capacity, strength, durability and fluidity of the fluidized solidified soil in different application scenarios meet the corresponding requirements.
[0042] After step 2, mold forming and standard curing steps are also included. The fluidized solidified soil for capturing and storing carbon dioxide is poured into a mold to prepare an unconfined compressive test block. After demoulding, it is wrapped with plastic wrap and cured in a standard curing room to reach the designed strength. The temperature of the standard curing room is 18°C-22°C, and the relative humidity is ≥95%. After the curing is completed, the seven-day unconfined compressive strength, carbon dioxide adsorption and fluidity of the prepared fluidized solidified soil are measured.
[0043] In the following examples, clay was collected on-site on a sunny day; cement was sourced from Shanghai Jinshan Nanfang Cement Co., Ltd., including two types, P.II52.5 and P.O42.5; fly ash was sourced from Shanghai Shuntao Industrial (Group) Co., Ltd., and was Class F, Grade II; KSW-3 high-efficiency water reducer was sourced from Hefei Kingsway New Building Materials Co., Ltd., ZWL-A-IX high-efficiency water reducer was sourced from Zhejiang Wulong New Materials Co., Ltd., and RAWY101 polycarboxylic acid high-performance water reducer was sourced from Anhui China Railway Engineering Materials Technology Co., Ltd.
[0044] Example 1
[0045] Preparation of porous coal tar particles: The coal tar is placed in a high-temperature furnace and heated to 100°C to make it a solid-solution mixed state. After the 40% by mass fraction of PAN and the 30% by mass fraction of PVP are dissolved, an organic polymer solution is obtained and heated to 60°C. The heated coal tar and organic polymer solution are evenly mixed in a mass ratio of 0.9:1 to ensure that the two are in full contact. Then, they are placed in an electric heating tubular furnace and heated at 400°C for 2 hours to obtain porous coal tar. After cooling to room temperature, it is washed with water and ethanol and sieved to obtain porous coal tar particles. It has been determined that the carbon dioxide adsorption capacity of the porous coal tar particles is 4.72 mmol / g, the particle size is 2.2 mm, and the specific surface areas before and after activation and pore formation are 17.35 m 2 / g and 1038m 2 / g.
[0046] 30kg of clay, 5kg of porous coal tar particles prepared by the above method, 40kg of P.II52.5 cement, and 10kg of Class F II fly ash were added to a horizontal mixer in sequence and stirred slowly. 0.3kg of KSW-3 high-efficiency water reducer was diluted with 14.7kg of water and added to the horizontal mixer together and stirred rapidly for 5 minutes to obtain fluidized solidified soil for capturing and storing carbon dioxide. It was poured into a mold to prepare an unconfined compression test block. After demoulding, it was wrapped with plastic wrap and cured in a standard curing room to measure its performance. Figure 2-Figure 4 As shown, the seven-day unconfined compressive strength is 5.3MPa, the carbon dioxide adsorption capacity is 23.6mol, and the fluidity is 208mm.
[0047] Example 2
[0048] The preparation method of porous coal tar pitch particles is the same as that in Example 1.
[0049] 30kg of clay, 10kg of porous coal tar particles, 35kg of P.II52.5 cement, and 10kg of Class F II fly ash were added to a horizontal mixer in sequence and stirred slowly. 0.3kg of KSW-3 high-efficiency water reducer was diluted with 14.7kg of water and added to the horizontal mixer together and stirred rapidly for 5 minutes to obtain a fluidized solidified soil for capturing and storing carbon dioxide. The soil was poured into a mold to prepare an unconfined compression test block. After demoulding, it was wrapped with plastic wrap and cured in a standard curing room to measure its performance. Figure 2-Figure 4 As shown, the seven-day unconfined compressive strength is 3.6MPa, the carbon dioxide adsorption capacity is 47.2mol, and the fluidity is 193mm.
[0050] Example 3
[0051] The preparation method of porous coal tar pitch particles is the same as that in Example 1.
[0052] 30kg of clay, 15kg of porous coal tar particles, 30kg of P.II52.5 cement, and 10kg of Class F II fly ash were added to a horizontal mixer in sequence and stirred slowly. 0.3kg of ZWL-A-IX high-efficiency water reducer was diluted with 14.7kg of water and added to the horizontal mixer together and stirred rapidly for 5 minutes to obtain a fluidized solidified soil for capturing and storing carbon dioxide. The soil was poured into a mold to prepare an unconfined compression test block. After demoulding, it was wrapped with plastic wrap and cured in a standard curing room to measure its performance. Figure 2-Figure 4 As shown, the seven-day unconfined compressive strength is 2.9MPa, the carbon dioxide adsorption capacity is 70.8mol, and the fluidity is 180mm.
[0053] Example 4
[0054] The preparation method of porous coal tar pitch particles is the same as that in Example 1.
[0055] 20kg clay, 30kg porous coal tar particles, 25kg P.O42.5 cement, and 10kg F class II fly ash were added to a horizontal mixer in sequence and stirred slowly. 0.3kg ZWL-A-IX high efficiency water reducer was diluted with 14.7kg water and added to the horizontal mixer together and stirred rapidly for 5 minutes to obtain a fluidized solidified soil for capturing and storing carbon dioxide. The soil was poured into a mold to prepare an unconfined compression test block. After demoulding, it was wrapped with plastic wrap and cured in a standard curing room to measure its performance. Figure 2-Figure 4 As shown, the seven-day unconfined compressive strength is 2.2MPa, the carbon dioxide adsorption capacity is 141.6mol, and the fluidity is 153mm.
[0056] Example 5
[0057] The preparation method of porous coal tar pitch particles is the same as that in Example 1.
[0058] 20kg clay, 35kg porous coal tar particles, 20kg P.O42.5 cement, and 10kg F-class II fly ash were added to a horizontal mixer in sequence and stirred slowly. 0.3kg RAWY101 polycarboxylic acid high-performance water reducer was diluted with 14.7kg water and added to a horizontal mixer and stirred rapidly for 5 minutes to obtain a fluidized solidified soil for capturing and storing carbon dioxide. The soil was poured into a mold to prepare an unconfined compression test block. After demoulding, it was wrapped with plastic wrap and cured in a standard curing room to measure its performance. Figure 2-Figure 4 As shown, the seven-day unconfined compressive strength is 1.8MPa, the carbon dioxide adsorption capacity is 165.2mol, and the fluidity is 137mm.
[0059] Example 6
[0060] The preparation method of porous coal tar pitch particles is the same as that in Example 1.
[0061] 20kg clay, 40kg porous coal tar particles, 15kg P.O42.5 cement, and 10kg F-class II fly ash were added to a horizontal mixer in sequence and stirred slowly. 0.3kg RAWY101 polycarboxylic acid high-performance water reducer was diluted with 14.7kg water and added to a horizontal mixer and stirred rapidly for 5 minutes to obtain a fluidized solidified soil for capturing and storing carbon dioxide. The soil was poured into a mold to prepare an unconfined compression test block, which was then wrapped with plastic wrap and cured in a standard curing room after demoulding to measure its performance. Figure 2-Figure 4 As shown, the seven-day unconfined compressive strength is 1.1MPa, the carbon dioxide adsorption capacity is 188.8mol, and the fluidity is 113mm.
[0062] As can be seen from the above test results, with the reduction of cement addition, the seven-day unconfined compressive strength of the fluidized solidified soil also decreases significantly therewith, mainly because the dicalcium silicate and tricalcium silicate generated by cement hydration are greatly reduced, and these two substances are the main strength sources of the fluidized solidified soil. With the increase of the addition of porous coal tar particles, the carbon dioxide adsorption of the fluidized solidified soil also increases significantly therewith, because the porous coal tar particles with high porosity can adsorb more carbon dioxide. The fluidity of the fluidized solidified soil prepared in Example 1-6 is between 110mm-220mm, which meets the construction requirements. With the reduction of cement content, the content of porous coal tar particles increases, and the fluidity is on a downward trend, because the particle size (millimeter level) of porous coal tar particles is larger than the particle size (micrometer level) of cement, and the voids of the fluidized solidified soil increase, and cement is gradually insufficient to fill the voids of the fluidized solidified soil, and there is not enough cement to wrap the porous coal tar particles. The content ratio of each component can be selected according to actual needs. If the strength of the fluidized solidified soil, the amount of carbon dioxide adsorption and the fluidity are taken into consideration at the same time, the optimal ratio of each component is shown in Example 4.
[0063] In summary, the present invention mixes an organic high molecular polymer solution with good compatibility with coal tar pitch evenly and then undergoes a cross-linking reaction under high temperature conditions. At the same time, the small molecule gas generated by the pyrolysis reaction of the organic high molecular polymer solution is evenly distributed in the liquid coal tar pitch. As the reaction proceeds, the small molecule gas gradually volatilizes. After cooling, more uniform pores are formed in the coal tar pitch to obtain porous coal tar pitch particles and apply them to fluidized solidified soil. The prepared fluidized solidified soil has excellent carbon dioxide capture, utilization and storage capabilities, is conducive to reducing carbon dioxide emissions, and mitigates climate change. It has high environmental protection performance and can meet the strength, durability and fluidity requirements of fluidized solidified soil in engineering applications. In addition, the industrial byproduct of coal tar pitch is used as a substrate to achieve the recycling of resources. Two organic high molecular polymers, PAN and PVP, are used to activate and form pores in coal tar pitch without the use of chemical reagents such as strong acids and alkalis, which greatly reduces pollution to the environment. At the same time, the activation and pore-forming reaction process is controllable, and the entire fluidized solidified soil preparation method is simple, low cost, and has good application prospects.
[0064] Although the content of the present invention has been described in detail through the above preferred embodiments, it should be appreciated that the above description should not be considered as a limitation of the present invention. After reading the above content, it will be apparent to those skilled in the art that various modifications and substitutions of the present invention will occur. Therefore, the protection scope of the present invention should be limited by the appended claims.
Claims
1. A method for preparing fluidized solidified soil for capturing and storing carbon dioxide, characterized in that: The method includes: Step 1, crosslinking reaction and pyrolysis reaction of coal tar and organic polymer solution at 300-450° C. to obtain porous coal tar particles, wherein the organic polymer solution comprises at least one of polyacrylonitrile solution and polyvinyl pyrrolidone solution; Step 2: Mix the porous coal tar particles, cement, fly ash, clay, water and high-efficiency water reducing agent, and stir to form a fluidized solidified soil for capturing and storing carbon dioxide.
2. The method for preparing fluidized solidified soil for capturing and storing carbon dioxide according to claim 1, characterized in that: In the step 1, the coal tar pitch is heated to 90°C-110°C in advance, and the organic high molecular polymer solution is heated to 50°C-70°C in advance.
3. The method for preparing fluidized solidified soil for capturing and storing carbon dioxide according to claim 1, characterized in that: In the step 1, the mass ratio of the coal tar pitch and the organic high molecular polymer solution is (0.7-1.0): (0.8-1.1), and the heating time is 1.5-2.5h.
4. The method for preparing fluidized solidified soil for capturing and storing carbon dioxide according to claim 1, characterized in that: The particle size of the porous coal tar pitch particles is 1.18 mm to 4.75 mm, and the mass fraction of the porous coal tar pitch particles in the fluidized solidified soil for capturing and storing carbon dioxide is 5% to 40%.
5. The method for preparing fluidized solidified soil for capturing and storing carbon dioxide according to claim 1, characterized in that: In the step 2, the mass fraction of cement in the fluidized solidified soil for capturing and storing carbon dioxide is 15%-40%.
6. The method for preparing fluidized solidified soil for capturing and storing carbon dioxide according to claim 1, characterized in that: In the step 2, the mass fraction of fly ash in the fluidized solidified soil for capturing and storing carbon dioxide is 5%-20%.
7. The method for preparing fluidized solidified soil for capturing and storing carbon dioxide according to claim 1, characterized in that: In the step 2, the mass fraction of clay in the fluidized solidified soil for capturing and storing carbon dioxide is 10%-30%.
8. The method for preparing fluidized solidified soil for capturing and storing carbon dioxide according to claim 1, characterized in that: In the step 2, the mass fraction of water in the fluidized solidified soil for capturing and storing carbon dioxide is 10%-20%.
9. The method for preparing fluidized solidified soil for capturing and storing carbon dioxide according to claim 1, characterized in that: In the step 2, the high-efficiency water reducer includes any one of KSW-3 high-efficiency water reducer, ZWL-A-IX high-efficiency water reducer, and RAWY101 polycarboxylic acid high-performance water reducer, and the mass fraction of the high-efficiency water reducer in the fluidized solidified soil for capturing and storing carbon dioxide is 0.2%-0.5%.
10. A fluidized solidified soil for capturing and storing carbon dioxide obtained according to the preparation method according to claims 1-9.