Method and structure for co2 sequestration by solid waste-based polymers

Abstract

The present application belongs to the technical field of industrial solid waste resource utilization and CO2 sequestration, and relates to a method and structure for sequestrating CO2 by using geopolymer of solid waste. The method comprises the following steps: firstly, preparing a precast slab by pouring and curing geopolymer A; secondly, splicing the precast slab to form a three-dimensional precast piece, penetrating an injection pipe into one side of the three-dimensional precast piece, and coating geopolymer A on the area outside the precast piece except the injection pipe opening, and completely final setting to form a geopolymer airtight layer, thereby obtaining an isolation box for sequestrating CO2; thirdly, pumping geopolymer B and liquid CO2 into the isolation box for sequestrating CO2 through the injection opening, and plugging the injection pipe opening after the pumping is completed; and finally, coating silica sol on the outside of the isolation box for sequestrating CO2 to plug the air holes, and completing the CO2 sequestration. The method can not only sequestrate CO2 physically and chemically synchronously, but also realize the resource utilization of solid waste, thereby reducing the pollution of land and environment caused by the solid waste stacking and the greenhouse effect caused by the CO2 emission.

Description

Technical Field

[0001] The present invention belongs to the technical field of industrial solid waste resource utilization and CO2 sequestration, and relates to a method and structure for sequestering CO2 using a solid waste-based polymer. Background Art

[0002] Global warming has become a widespread concern and urgent issue for the international community. Carbon sequestration technologies hold great potential for reducing CO2 emissions from energy systems. These technologies include chemical sequestration of CO2 through solid waste mineralization and direct geophysical sequestration of CO2. CO2 solid waste mineralization involves reacting solid waste rich in calcium, magnesium, and other substances with CO2 to produce stable inorganic carbonates, thereby capturing and storing CO2 over the long term. However, this method requires a high level of solid waste type, requiring it to contain a high concentration of active alkaline metals to achieve stoichiometric storage, limiting the amount of CO2 stored. Geological CO2 sequestration involves direct injection of CO2 into deep saline aquifers, depleted oil and gas reservoirs, and other geological structures at depths between 800 and 3,500 meters. Over 90% of the total geological storage potential lies in deep saline aquifers, and only a few areas on land have the conditions, making it limited in scope.

[0003] Nowadays, with the development of industry, solid waste piles contain many impurities and harmful substances, which are difficult to handle. Their storage puts tremendous pressure on resources and the environment.

[0004] Current research has shown that steel slag has inherent alkalinity and that calcium oxide (CaO) and magnesium oxide (MgO) exhibit higher reactivity after dissolution in aqueous solutions, making it more suitable for mineral carbonation. Using steel slag for mineralization and CO2 fixation can transfer unstable components (such as free CaO and MgO, which may cause expansion and cracking of concrete, and the dissolution of heavy metals such as vanadium and chromium, which may pollute soil and groundwater) into carbonates, which not only reduces CO2 emissions but also solves the stability problem of steel slag concrete. Fly ash, as a basic industrial solid waste, has an abundant output despite a relatively low free CaO content. Since fly ash has a desulfurization efficiency of 30-45% and contains 20-30% CaO, circulating fluidized bed fly ash generally has a high CO2 sequestration capacity.

[0005] Chinese invention patent application CN116060414A discloses a method for enhancing carbon dioxide sequestration and utilization using slurry solid waste. The method uses solid waste materials mainly composed of fly ash and carbon-fixing materials mainly composed of steel slag. High-flow, low-viscosity, slow-setting solid waste slurry is injected into the oil reservoir to assist in carbon dioxide flooding. Compared with traditional backfilling of oil-based drilling waste, the method has a variety of solid waste options and can accommodate large amounts of industrial solid waste, thus achieving multiple utilization of solid waste.

[0006] However, current research on solid waste mineralization and storage primarily focuses on steel slag and fly ash. However, current industrial solid waste presents challenges such as high emissions and a wide variety of waste types. To fully realize resource reuse, in-depth research on the application of various industrial solid wastes in CO2 storage is necessary. Furthermore, during physical geological storage, CO2 injection alters physical parameters such as reservoir density, resistivity, and seismic wave velocity, providing the physical property prerequisites for safety monitoring using geophysical methods such as seismic and electromagnetic methods. Therefore, synergizing physical geological storage with chemical mineralization and storage of solid waste is expected to become the most feasible technical approach to addressing the issues of solid waste storage and carbon emission reduction. Summary of the Invention

[0007] In response to the problems existing in the prior art, the present invention provides a method and structure for storing CO2 in solid waste-based polymers, which can achieve waste reduction, resource utilization and safe disposal while also reducing CO2 emissions.

[0008] The technical solutions of the present invention are as follows:

[0009] A method for storing CO2 using polymers in a solid waste base, the method specifically comprising the following steps:

[0010] (1) Preparation of precast panels: The geopolymer A is poured and cured to obtain the precast panels;

[0011] (2) Preparation of an isolation box for storing CO2: The prefabricated panels prepared in step (1) are assembled into a three-dimensional prefabricated part, an injection pipe is inserted through one side of the three-dimensional prefabricated part, and geopolymer A is coated on the area outside the prefabricated part except for the injection pipe opening, and the geopolymer A is completely final-set to form a geopolymer sealing layer;

[0012] (3) Injection process: pump geopolymer B and liquid CO2 into the isolation box for storing CO2 through the injection pipe, and then seal the injection pipe opening after completion;

[0013] (4) Sealing process: Apply silica sol outside the isolation box for storing CO2 to seal the pores and complete the CO2 sealing.

[0014] Furthermore, the geopolymer A is prepared from at least one industrial solid waste including carbide slag, slag, steel slag, and coal-fired solid sulfur ash (CFB ash); the geopolymer B is prepared from industrial solid waste including carbide slag; and the carbide slag content in the geopolymer B is higher than that in the geopolymer A.

[0015] Furthermore, the geopolymer A is also prepared from at least one industrial solid waste including desulfurization gypsum, fly ash, silicomanganese slag and coal gangue; the geopolymer B is also prepared from at least one industrial solid waste including slag, steel slag and coal-fired fixed sulfur ash (CFB ash).

[0016] Furthermore, the geopolymer B is also prepared from at least one industrial solid waste selected from desulfurized gypsum, fly ash, silico-manganese slag and coal gangue.

[0017] In the present invention, the industrial solid waste carbide slag contains a large amount of calcium ions and can be used as an alkaline activator; steel slag and mineral slag contain active minerals such as tricalcium silicate (Ca3SiO5), dicalcium silicate (Ca2SiO4) and ferroaluminate with hydraulic gelling properties, and have cement properties; coal-fired solid sulfur ash (CFB ash) contains fly ash and calcium sulfate, as well as incompletely reacted calcium oxide (or carbide slag), which also has high activity and can produce higher early strength; in addition, the above-mentioned industrial solid waste is further combined with silicon and aluminum elements in solid wastes such as fly ash and coal gangue to generate amorphous colloids of calcium vanadium and CASH, producing higher strength.

[0018] Therefore, in order to achieve better CO2 storage effect and prevent leakage, the present invention provides higher early strength for geopolymer A by selecting the type of industrial solid waste; secondly, the CO2 injected into the isolation box can further react with the alkaline calcium and magnesium ions inside it to generate calcium carbonate and expand the volume when it comes into contact with the geopolymer A prefabricated board, further sealing the pores, and preventing CO2 leakage with multiple layers of insurance.

[0019] Preferably, the geopolymer A and geopolymer B are prepared from at least three types of industrial solid wastes. When the three solid waste components, especially when the three solid wastes contain at least one of carbide slag, slag, steel slag, and coal-fired fixed sulfur ash (CFB ash), the solid wastes can react with each other to form calcium aluminate that can provide early strength and CASH amorphous colloid that can provide long-term strength, thereby generating a positive gain in the mechanical properties of the geopolymer.

[0020] More preferably, the amount of any one type of industrial solid waste is 10-50% of the total amount of industrial solid waste. When a certain component is too much, resulting in too little other components, the components and elements required for reaction balance cannot be provided, and the mechanical properties of the geopolymer finally formed will be seriously affected, which will eventually lead to a certain impact on the sealing effect (sealing).

[0021] When the industrial solid waste used in the preparation process of polymer A is at least three types:

[0022] Optionally, the industrial solid waste is any one of carbide slag, slag, steel slag, coal-fired sulfur-binding ash (CFB ash), and at least two of desulfurization gypsum, fly ash, silicomanganese slag and coal gangue; or any two of carbide slag, slag, steel slag, coal-fired sulfur-binding ash (CFB ash), and at least one of desulfurization gypsum, fly ash, silicomanganese slag and coal gangue; or at least three of carbide slag, slag, steel slag, coal-fired sulfur-binding ash (CFB ash); or at least three of carbide slag, slag, steel slag, coal-fired sulfur-binding ash (CFB ash), and at least one of desulfurization gypsum, fly ash, silicomanganese slag and coal gangue.

[0023] When the industrial solid waste used in the preparation process of polymer B is at least three types:

[0024] Optionally, the industrial solid waste is carbide slag and at least two of desulfurization gypsum, fly ash, silicomanganese slag and coal gangue; or carbide slag and at least two of slag, steel slag, and coal-fired sulfur-binding ash (CFB ash); or carbide slag and at least one of slag, steel slag, and coal-fired sulfur-binding ash (CFB ash) and at least one of desulfurization gypsum, fly ash, silicomanganese slag and coal gangue.

[0025] Furthermore, the water-cement ratio of the geopolymer A is 0.3-0.7.

[0026] Furthermore, the water-cement ratio of the geopolymer B is 0.4-0.7.

[0027] Since the lower the water-cement ratio, the higher the strength of the geopolymer; in the present invention, by reasonably limiting the water-cement ratio of geopolymer A, the mechanical properties can be improved and a higher sealing effect can be achieved; and geopolymer B does not need to generate strength, but requires more alkaline substances to mineralize carbon dioxide, so more water can be added to help mineralization, and the water-cement ratio should be appropriately increased, but not too much. Too much will occupy more space for industrial solid waste and CO2, reduce the total amount of CO2 loaded, and reduce the CO2 storage efficiency.

[0028] Furthermore, the volume ratio of geopolymer B to liquid CO2 is 1:0.2-0.4. By controlling the volume ratio, geopolymer B contains a relatively high amount of alkaline elements, which are expected to undergo a long-term mineralization reaction with CO2 to form carbonates, thereby achieving better chemical storage and completely avoiding the risk of CO2 overflow. The geopolymer B and liquid CO2 can completely fill the interior space of the isolation box for CO2 storage.

[0029] Furthermore, in step (1), the curing temperature is 25-100° C., the curing humidity is 80-95%, and the curing time is 4-24 hours.

[0030] Furthermore, in step (4), the silica sol is selected from any one of acidic, neutral and alkaline, and the silica sol has a silicon dioxide content greater than 30%.

[0031] In some embodiments of the present invention, the geopolymer is prepared by mixing industrial solid wastes in a certain proportion, ball milling for 15-120 minutes, and adding water to mix.

[0032] Furthermore, the particle size of the industrial solid waste is less than 100 μm.

[0033] The present invention also provides a structure for implementing any of the above-mentioned methods for storing CO2 using solid waste-based polymers.

[0034] The structure is an isolation box for sealing CO2, which is composed of a three-dimensional prefabricated part, an injection pipe, and a geopolymer sealing layer coated on the outer layer of the three-dimensional prefabricated part except the injection pipe mouth; the outer layer of the isolation box is coated with a silica sol layer; the three-dimensional prefabricated part is spliced ​​by prefabricated panels; and the injection pipe runs through either side of the three-dimensional prefabricated part.

[0035] Furthermore, the thickness of the geopolymer sealing layer is 3-8 cm, and the side length or length and width can be adjusted according to actual needs. The geopolymer sealing layer can combine the three-dimensional prefabricated parts to form a complete closed wall and form an internal reserved space.

[0036] Furthermore, the thickness of the silica sol layer is 0.1-1 cm. The silica gel layer can further block the pores to prevent CO2 from leaking out.

[0037] Compared with the prior art, the present invention has the following beneficial effects:

[0038] (1) The present invention uses all solid waste to prepare geopolymers to prepare isolation boxes for storing CO2, which can solve the problem of large-scale disposal of solid waste, turn industrial solid waste into treasure, and realize its resource utilization.

[0039] (2) The present invention further screens the types of industrial solid waste and the dosage ratio of each component, as well as controls the ratio of geopolymer B and liquid CO2, which can achieve a better chemical sequestration effect of CO2.

[0040] (3) The present invention can achieve simultaneous physical and chemical storage of CO2, with a large storage capacity, strong applicability, low storage cost, and is more economical and practical, and can be promoted and used on a large scale.

[0041] (4) The B-geopolymer with more carbide slag content is synchronously injected with liquid CO2, and the generated calcium carbonate micro-nano particles can block the pores of the geopolymer A; the sol applied on the outermost layer of the cubic preform can further block the pores, avoid the exosmosis of CO2, and further ensure the long-term safe disposal of the geopolymer isolation tank storing CO2 in mines, pits, deep seas and the like. BRIEF DESCRIPTION OF DRAWINGS

[0042] Figure 1 The structure diagram of the solid waste-based geopolymer for storing CO2 according to the present application. DETAILED DESCRIPTION

[0043] The following non-limiting examples can make those skilled in the art more fully understand the present application, but do not limit the present application in any way. The following content is only an exemplary description of the scope of the present application, and those skilled in the art can make various changes and modifications to the present application according to the disclosed content, and it should also belong to the scope of the present application.

[0044] (1) Preparation of preform:

[0045] The geopolymer A is prepared into a preform with a certain thickness and size by pouring and forming, curing and strengthening. Figure 1 ).

[0046] In the present application, the curing temperature in the curing and strengthening process is 25-100℃, the curing humidity is 80-95%, and the curing time is 4-24 hours.

[0047] In the present application, the preparation method of the geopolymer A is as follows:

[0048] S1: One or more industrial solid wastes are mixed;

[0049] S2: The industrial solid waste or the mixed industrial solid waste is ball milled for 15-60 min to obtain solid waste particles with a particle size of less than 100 μm;

[0050] S3: Water is added to the solid waste particles and mixed uniformly to obtain the geopolymer A.

[0051] In the present application, the industrial solid waste includes at least one of carbide slag, slag, steel slag, and coal combustion desulfurization ash (CFB ash).

[0052] Preferably, the industrial solid waste further includes at least one of desulfurization gypsum, fly ash, silicon-manganese slag, and coal gangue.

[0053] Further preferably, the industrial solid waste is at least three kinds.

[0054] When there are at least three types of industrial solid waste, optionally, the industrial solid waste is any one of carbide slag, slag, steel slag, coal-fired sulfur-binding ash (CFB ash), and at least two of desulfurization gypsum, fly ash, silicomanganese slag and coal gangue; or any two of carbide slag, slag, steel slag, coal-fired sulfur-binding ash (CFB ash), and at least one of desulfurization gypsum, fly ash, silicomanganese slag and coal gangue; or at least three of carbide slag, slag, steel slag, coal-fired sulfur-binding ash (CFB ash); or at least three of carbide slag, slag, steel slag, coal-fired sulfur-binding ash (CFB ash), and at least one of desulfurization gypsum, fly ash, silicomanganese slag and coal gangue.

[0055] In the present invention, the water-cement ratio of the geopolymer A is 0.3-0.7.

[0056] (2) Preparation of isolation box for storing CO2:

[0057] The prefabricated panels prepared in step (1) are assembled into a three-dimensional prefabricated part, and an injection pipe is inserted through one side of the three-dimensional prefabricated part (see injection pipe). Figure 1 ), and a certain thickness of geopolymer A is coated on the outside of the prefabricated part except the injection nozzle, and the geopolymer is completely solidified to form a geopolymer sealing layer (see the geopolymer sealing layer). Figure 1 ) and form an internal reserved space for injecting liquid CO2, which can realize the physical storage of CO2.

[0058] In the present invention, when preparing an isolation box for sealing CO2, the industrial solid waste or water-cement ratio used in preparing the geopolymer A coated on the outer area of ​​the three-dimensional prefabricated part can be the same as the geopolymer A used in preparing the prefabricated board in step (1).

[0059] (3) Injection process:

[0060] Geopolymer B and liquid CO2 are pumped into the internal space of the isolation box for storing CO2 through the injection port. After completion, the injection pipe port is sealed, and the prefabricated board A with the same size and hole is pushed into the injection port, and then the geopolymer A is covered and locally heated and cured for 1 hour.

[0061] In the present invention, the preparation method of geopolymer B is the same as that of geopolymer A.

[0062] In the present invention, the industrial solid waste used in the preparation process of the geopolymer B includes carbide slag.

[0063] In the present invention, the industrial solid waste used in the preparation process of the geopolymer B further includes at least one of slag, steel slag, and coal-fired fixed sulfur ash (CFB ash).

[0064] In the present invention, the industrial solid waste used in the preparation process of the geopolymer B further includes at least one of desulfurized gypsum, fly ash, silico-manganese slag and coal gangue.

[0065] Preferably, at least three types of industrial solid waste are used in the preparation process of the geopolymer B.

[0066] When there are at least three types of industrial solid waste, optionally, the industrial solid waste is carbide slag and at least two of desulfurization gypsum, fly ash, silicomanganese slag and coal gangue; or carbide slag and at least two of slag, steel slag, and coal-fired solid sulfur ash (CFB ash); or carbide slag and at least one of slag, steel slag, and coal-fired solid sulfur ash (CFB ash) and at least one of desulfurization gypsum, fly ash, silicomanganese slag and coal gangue.

[0067] In the present invention, when the industrial solid waste used in the preparation process of geopolymer A and geopolymer B both include carbide slag, preferably, the carbide slag content in the industrial solid waste used in the preparation process of geopolymer B is higher than the carbide slag content in the industrial solid waste used in the preparation process of geopolymer A.

[0068] In the present invention, the water-cement ratio of the geopolymer B is 0.4-0.7.

[0069] The present invention can achieve chemical storage of CO2 by synchronously injecting geopolymer B and liquid CO2.

[0070] Furthermore, the volume ratio of the geopolymer B to liquid CO2 is 1:0.2-0.4. By controlling the volume ratio of the two, the geopolymer B contains more alkaline elements, and it is hoped that it can undergo a long-term mineralization reaction with CO2 to generate carbonate substances, thereby achieving better chemical storage and completely avoiding the risk of CO2 overflow.

[0071] (4) Plugging process:

[0072] Apply silica sol outside the isolation box for sealing CO2 (silica sol layer see Figure 1 ), plugging the pores and completing the CO2 storage. Further plugging with silica sol can effectively prevent CO2 leakage and further ensure the long-term safe disposal of the storage.

[0073] In the present invention, the silica sol is selected from one of acidic, neutral and alkaline, and the silicon dioxide content in the silica sol is greater than 30%.

[0074] As mentioned above, the present invention also provides a structure for implementing the above method (see Figure 1 ), the structure is an isolation box for sealing CO2, which is composed of a three-dimensional preform, an injection pipe and a geopolymer sealing layer coated on the outer layer of the three-dimensional preform except the injection pipe mouth; the outer layer of the isolation box is coated with a silica sol layer; the three-dimensional preform is spliced ​​by prefabricated panels; the injection pipe runs through either side of the three-dimensional preform.

[0075] In the present invention, the thickness of the geopolymer sealing layer is 3-8 cm, and the side length or length and width can be adjusted according to actual needs; the thickness of the silica sol layer is 0.1-1 cm.

[0076] The CO2 storage box produced using this solution is extremely airtight, with no leakage issues. Furthermore, as the mineralization reaction between geopolymer B and CO2 achieves chemical storage, the CO2 inventory and pressure inside the sealed box gradually decrease, completely eliminating the risk of CO2 overflow.

[0077] Finally, it should be noted that the above content is only used to illustrate the technical solution of the present invention, rather than to limit the scope of protection of the present invention. Simple modifications or equivalent substitutions of the technical solution of the present invention by ordinary technicians in this field do not deviate from the essence and scope of the technical solution of the present invention.

Claims

1. A method for storing CO2 using polymers in solid waste, characterized in that: The following steps are involved: (1) Preparation of precast panels: The geopolymer A is poured and cured to obtain the precast panels; (2) Preparation of an isolation box for storing CO2: The prefabricated panels prepared in step (1) are assembled into a three-dimensional prefabricated part, an injection pipe is inserted into one side of the three-dimensional prefabricated part, and geopolymer A is coated on the area outside the prefabricated part except for the injection pipe opening, and the geopolymer A is formed after complete final setting to form a geopolymer sealing layer; (3) Injection process: pump geopolymer B and liquid CO2 into the isolation box for storing CO2 through the injection pipe, and then seal the injection pipe opening after completion; (4) Sealing process: Apply silica sol outside the isolation box for storing CO2 to seal the pores and complete the CO2 storage; The geopolymer A is prepared from at least one industrial solid waste selected from carbide slag, slag, steel slag and coal-fired solid sulfur ash; and the geopolymer B is prepared from industrial solid waste selected from carbide slag.

2. The method according to claim 1, characterized in that The content of carbide slag in the geopolymer B is higher than that in the geopolymer A.

3. The method according to claim 2, characterized in that The geopolymer A is also prepared from at least one industrial solid waste including desulfurized gypsum, fly ash and coal gangue; the geopolymer B is also prepared from at least one industrial solid waste including slag, steel slag and coal-fired sulfur-fixing ash.

4. The method according to claim 3, characterized in that The geopolymer B is also prepared from at least one industrial solid waste selected from desulfurized gypsum, fly ash and coal gangue.

5. The method according to claim 4, characterized in that The geopolymer A and geopolymer B are prepared from at least three types of industrial solid wastes; the amount of each type of industrial solid waste is 10-50% of the total amount of industrial solid wastes.

6. The method according to any one of claims 2 to 5, characterized in that: The particle size of the industrial solid waste is less than 100 μm.

7. The method according to claim 1, characterized in that The water-cement ratio of the geopolymer A is 0.3-0.7; the water-cement ratio of the geopolymer B is 0.4-0.7; and the volume ratio of the geopolymer B to liquid CO2 is 1:0.2-0.

4.

8. The method according to claim 1, characterized in that In step (1), the curing temperature is 25-100° C., the curing humidity is 80-95%, and the curing time is 4-24 hours; in step (4), the silica sol is selected from any one of acidic, neutral and alkaline, and the silica content in the silica sol is greater than 30%.

9. A structure for implementing the method according to any one of claims 1 to 8, characterized in that: The structure is an isolation box for sealing CO2, which is composed of a three-dimensional prefabricated part, an injection pipe, and a geopolymer sealing layer coated on the outer layer of the three-dimensional prefabricated part except the injection pipe mouth; the outer layer of the isolation box is coated with a silica sol layer; the three-dimensional prefabricated part is spliced ​​by prefabricated panels; and the injection pipe runs through either side of the three-dimensional prefabricated part.

10. The structure according to claim 9, characterized in that The thickness of the geopolymer sealing layer is 3-8 cm, and the thickness of the silica sol layer is 0.1-1 cm.

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