Method for sealing carbon dioxide by using underground chamber

Abstract

The invention discloses a method for sealing and storing carbon dioxide through an underground chamber, and belongs to the technical field of carbon dioxide sealing and storing. The method for sealing and storing the carbon dioxide comprises the steps that S1, a continuous alkali release lining is constructed in an underground chamber; and S2, collecting carbon dioxide, and conveying the carbon dioxide to the underground chamber for sealing and storing the carbon dioxide. Through layered storage of gaseous, liquid and supercritical carbon dioxide, different geological conditions and storage requirements are met, and the technical limitation of a single phase state is broken through. The osmotic pressure gradient generated by carbon dioxide phase change and the surrounding rock ground stress are dynamically balanced, the active supporting strength and the maintenance frequency are reduced, and the engineering cost is saved. A high-alkalinity sulphoaluminate cement-based composite material and a nano modification technology are adopted, so that the corrosion resistance, the interface shear strength and the elastic modulus of the lining are remarkably improved. And the carbon dioxide and the lining material are subjected to mineral carbonization reaction to generate carbonate, so that the surrounding rock-lining interface strength is enhanced, and meanwhile, the sealing efficiency and the geological stability are improved.

Description

Technical Field

[0001] This invention belongs to the field of carbon dioxide sequestration technology, specifically relating to a method for sequestering carbon dioxide using an underground chamber. Background Technology

[0002] Currently, carbon dioxide sequestration technology mainly focuses on two major directions: geological sequestration and marine sequestration. Geological sequestration: This method utilizes geological structures such as depleted oil and gas reservoirs, deep saline aquifers, or unminable coal seams to store carbon dioxide. However, this method relies on specific geological conditions (such as sealed caprocks or high-porosity reservoirs) and faces challenges such as difficulty in monitoring leakage risks and uncertainty regarding long-term stability.

[0003] Ocean sequestration involves injecting carbon dioxide into the deep sea or converting it into hydrates for storage, but it faces obstacles such as ecological damage, high technical costs, and restrictions imposed by international regulations.

[0004] In current technologies, underground chambers are mostly used for material storage or military purposes, while research on converting them into carbon dioxide sequestration sites is still lacking. Traditional chamber sequestration faces the following bottlenecks: Material corrosion problem: Carbon dioxide dissolves in water to form carbonic acid, which corrodes the concrete lining over a long period of time, leading to structural deterioration and leakage risks.

[0005] Ground stress imbalance: The osmotic pressure generated by the phase change of carbon dioxide during the storage process is difficult to coordinate with the ground stress of the surrounding rock, requiring frequent reinforcement of the support structure, which is costly.

[0006] Low storage efficiency: Single-phase storage (such as supercritical state) is limited by geological conditions and is difficult to adapt flexibly to multiple scenarios.

[0007] Therefore, there is an urgent need for a new carbon dioxide sequestration method that can not only make efficient use of underground chamber resources, but also break through existing technical bottlenecks through material innovation and mechanical mechanism optimization. Summary of the Invention

[0008] In view of this, the purpose of this invention is to provide a method for sequestering carbon dioxide using underground chambers. This invention utilizes the stratified sequestration of gaseous, liquid, and supercritical carbon dioxide to adapt to different geological conditions and sequestration requirements, overcoming the technical limitations of single-phase storage. It achieves dynamic equilibrium by utilizing the osmotic pressure gradient generated by the phase change of carbon dioxide and the surrounding rock stress, thereby improving both sequestration efficiency and geological stability.

[0009] To achieve the above objectives, the present invention provides the following technical solution: This invention provides a method for sealing carbon dioxide using an underground chamber, comprising the following steps: S1. Construct a continuous alkali-releasing lining in the underground chamber; S2. Collect carbon dioxide and transport it to an underground chamber for storage.

[0010] Furthermore, the underground chambers in S1 are divided into shallow underground chambers with a depth of less than 300m, medium underground chambers with a depth of 300~800m, and deep underground chambers with a depth of more than 800m.

[0011] Furthermore, the preparation method of the continuously alkali-releasing lining material in S1 is as follows: a high alkalinity sulfoaluminate cement-based composite material with pH≥13.2 is used as the lining body, and then 12-15wt% of nano-silica and 12-15wt% of calcium-magnesium binary activator are added.

[0012] Furthermore, the high-alkalinity sulfoaluminate cement-based composite material comprises 85 wt% sulfoaluminate cement clinker, 10 wt% gypsum stone, and 5 wt% limestone; the nano-silica particles have a size of 20-50 nm; and the calcium-magnesium binary activator contains CaO:MgO = 4:1.

[0013] Furthermore, the type of chamber requires a certain amount of storage space and should be located away from dangerous areas such as geological structural zones, high-temperature zones, and permeable areas that are prone to damage to the surrounding rock of the reservoir, to prevent carbon dioxide escape due to geological structural damage. The surrounding rock of the chamber should have a certain strength and low permeability to ensure stable carbon dioxide sequestration and prevent leakage. It should also have inexpensive transportation facilities to facilitate carbon dioxide injection and harvesting, as well as the transportation of chamber modification materials.

[0014] This invention employs a continuous alkali release system with a pH ≥ 13.2 to neutralize the acidic corrosion of carbon dioxide by using the above-mentioned technical solution; nano-silica fills micro-cracks, calcium and magnesium activators promote mineral carbonization, and the interfacial shear strength is improved; mineral precipitation increases the elastic modulus of the lining and improves the bending stiffness of the chamber.

[0015] Furthermore, the carbon dioxide in S2 is any one or more of supercritical carbon dioxide, gaseous carbon dioxide, and liquid carbon dioxide.

[0016] Furthermore, the gaseous carbon dioxide is stored in a shallow underground chamber with a depth of less than 300m, the liquid carbon dioxide is stored in a middle underground chamber with a depth of 300~800m, and the supercritical carbon dioxide is stored in a deep underground chamber with a depth of more than 800m.

[0017] Furthermore, the CO2 storage capacity in the underground chamber is as follows: calculate; in For CO2 mass, The density of CO2 Let be the volume of the chamber.

[0018] Furthermore, different delivery pipelines are used according to different forms of carbon dioxide; Supercritical carbon dioxide is transported through carbon steel pipelines. The interior of the carbon steel pipelines is coated with epoxy resin or polyurethane with a thickness of ≥250μm. At the same time, film-forming amine corrosion inhibitors are added to suppress electrochemical corrosion. Gaseous carbon dioxide is supplied through alloy steel pipes, with the inner coating made of polyvinylidene fluoride for impermeability treatment. Liquid carbon dioxide is supplied through high-density polyethylene pipes.

[0019] Furthermore, the underground chamber can be equipped with recycling pipelines to obtain carbon dioxide when needed.

[0020] Furthermore, the chamber requires sealing measures, including the lining of the chamber and the sealing of the transport pipeline. The pipeline welding must use highly weldable materials, and the welds must be subjected to ultrasonic non-destructive testing to ensure that there are no defects such as cracks or pores. After welding, heat treatment is required to improve the sealing durability.

[0021] It contains at least the following beneficial technical effects: This invention transports carbon dioxide of different phases to underground chambers at different depths for storage via pipelines and cages. Through a gas-rock coupling mechanism, it achieves dynamic equilibrium between the osmotic pressure gradient formed during carbon dioxide storage and the surrounding rock stress field. Based on the principle of pore pressure-stress synergistic optimization, it can reduce the peak load requirement of the chamber support structure. At the same time, it induces fracture closure through stress redistribution, forming a self-sustaining closed system.

[0022] This technical approach reduces the intensity of active support and the frequency of maintenance, while leveraging the potential of carbon dioxide phase transformation and mineral carbonization to improve carbon dioxide sequestration efficiency and ensure geological stability over millennia. The newly formed carbonate minerals undergo interface reconstruction with silicate minerals in the surrounding rock, increasing the shear strength of the lining-surrounding rock interface. Mineral precipitation increases the elastic modulus of the lining, significantly improving the flexural stiffness of the chamber. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of a carbon dioxide sequestration structure.

[0024] In the diagram: 1-Collection pipeline; 2-Carbon dioxide processing workshop; 3-Gaseous conveying pipeline; 4-Liquid conveying pipeline; 5-Supercritical conveying pipeline; 6-Shallow underground chamber; 7-Lined; 8-Middle underground chamber; 9-Deep underground chamber; 10-Gaseous recovery pipeline; 11-Liquid recovery pipeline; 12-Supercritical recovery pipeline; 13-Workshop; 14-Output pipeline.

[0025] Figure 2This is a diagram of the test equipment.

[0026] Figure 3 The images show the test specimens: (a) is a concrete specimen, (b) is a sandstone specimen, and (c) is a granite specimen.

[0027] Figure 4 The stress-strain curves of specimens under CO2 action at different depths and in different phases are shown. Detailed Implementation

[0028] Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of this invention. The invention will now be described with reference to specific embodiments. It should be noted that these embodiments are merely descriptive and do not limit the invention in any way. The invention will be further described in detail with reference to the accompanying drawings.

[0029] Example Combination Figure 1 The procedure for carbon dioxide sequestration is explained below: The underground chambers selected include shallow underground chambers (280m), medium underground chambers (560m), and deep underground chambers (910m), with the specific depth adjusted according to the temperature and pressure in the actual project. A lining (7) is constructed in the underground chamber. The lining is prepared by using a high-alkalinity sulfoaluminate cement-based composite material (85% sulfoaluminate cement clinker, 10% gypsum stone, and 5% limestone) with pH≥13.2 as the main body of the lining, and incorporating 13% nano-silica (particle size 40nm) and calcium-magnesium binary activator (CaO:MgO=4:1).

[0030] The collected carbon dioxide is transported to the carbon dioxide processing plant (2) via the collection pipeline (1), where it is processed into supercritical carbon dioxide, gaseous carbon dioxide or liquid carbon dioxide.

[0031] Low-pressure gaseous carbon dioxide is transported through a gaseous transport pipeline (3) to a shallow underground chamber (6) for storage. When carbon dioxide is needed, it is recovered through a gaseous recovery pipeline (10) to the workshop (13) and output through an output pipeline (14).

[0032] The liquid low-pressure liquid transport pipeline (4) transports the liquid to the central underground chamber (8) for storage. When carbon dioxide is needed, it is recovered to the workshop (13) through the liquid recovery pipeline (11) and output through the output pipeline (14).

[0033] Supercritical high-pressure carbon dioxide is transported to a deep underground chamber (9) via a supercritical state transport pipeline (5) for storage. When carbon dioxide is needed, it is recovered to the workshop (13) via a supercritical state recovery pipeline (12) and output via an output pipeline (14).

[0034] Effect Detection: An experimental study was conducted using a deep formation supercritical CO2 injection control and monitoring simulation system to investigate the effects of different CO2 phases on reservoir rocks and reservoir linings. The experimental equipment included... Figure 2 As shown, the temperature and pressure control system of this equipment can ensure that CO2 is in a specified phase, the axial pressure-confining pressure system can be used to measure the changes in the mechanical properties of the specimen after CO2 action, and the triaxial pressure chamber ensures that there is no risk of gas leakage. Figure 3 The images show some of the specimens. The specimens selected were concrete, granite, sandstone, and coal, which were used to simulate the influence of different phases of CO2 sequestration on the mechanical shape of the chamber lining, the goaf rock, and the remaining coal pillar.

[0035] Figure 4 Stress-strain curves of specimens under CO2 exposure at different depths and in different phases (partial specimen curves) (1) Under the influence of different phases of CO2, the peak strength, elastic modulus and corrosion resistance coefficient of concrete lining were improved compared with unsoaked concrete. In particular, under supercritical CO2 immersion, the peak strength and elastic modulus of concrete were significantly improved, which were 122% and 141.9% higher than those in the natural state, respectively.

[0036] (2) With the change of phase (gas-liquid-supercritical state), the total energy and dissipated energy of the concrete specimen showed a gradual increasing trend, while the elastic energy showed the opposite trend. The energy change in the supercritical state was the most significant. The plastic deformation capacity and ductility of the concrete specimen were significantly improved compared with the natural state.

[0037] (3) For concrete specimens, the permeability decreased under the action of CO2, decreasing by 15% under normal pressure and 64% under supercritical conditions. The decrease in permeability effectively improved the safety and efficiency of the sealing process.

[0038] (3) In CO2 geological sequestration, different strata depths require matching corresponding CO2 phases: gaseous CO2 sequestration is suitable for shallow strata, while supercritical CO2 is more suitable for deep strata. Specifically: At the same depth, supercritical CO2 has a significantly stronger deterioration effect on the surrounding rock than gaseous CO2. As the depth increases, the difference in the influence of different phases of CO2 on the rock gradually decreases, but supercritical CO2 has a stronger storage capacity advantage due to its higher initial storage pressure.

[0039] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for sealing carbon dioxide using an underground chamber, characterized in that, Includes the following steps: S1. Construct a continuous alkali-releasing lining in the underground chamber; S2. Collect carbon dioxide and transport it to an underground chamber for storage.

2. The method according to claim 1, characterized in that, The underground chambers in S1 are divided into shallow underground chambers with a depth of less than 300m, medium underground chambers with a depth of 300~800m, and deep underground chambers with a depth of more than 800m.

3. The method according to claim 1, characterized in that, The preparation method of the continuously alkali-releasing lining material in S1 is as follows: a high alkalinity sulfoaluminate cement-based composite material with pH≥13.2 is used as the lining body, and then 12-15wt% of nano-silica and 12-15wt% of calcium-magnesium binary activator are added.

4. The method according to claim 3, characterized in that, The high-alkalinity sulfoaluminate cement-based composite material comprises 85 wt% sulfoaluminate cement clinker, 10 wt% gypsum stone, and 5 wt% limestone; the nano-silica particles have a size of 20-50 nm; and the calcium-magnesium binary activator contains CaO:MgO = 4:

1.

5. The method according to claim 1, characterized in that, The carbon dioxide in S2 is in the form of any one or more of supercritical carbon dioxide, gaseous carbon dioxide, and liquid carbon dioxide.

6. The method according to claim 5, characterized in that, The gaseous carbon dioxide is stored in shallow underground chambers with a depth of less than 300m, the liquid carbon dioxide is stored in middle underground chambers with a depth of 300~800m, and the supercritical carbon dioxide is stored in deep underground chambers with a depth of more than 800m.

7. The method according to claim 6, characterized in that, The CO2 storage capacity in the underground chamber is as follows: calculate; in For CO2 mass, The density of CO2 Let be the volume of the chamber.

8. The method according to claim 4, characterized in that, Different delivery pipelines are used depending on the form of carbon dioxide; Supercritical carbon dioxide is transported through carbon steel pipelines. The interior of the carbon steel pipelines is coated with epoxy resin or polyurethane with a thickness of ≥250μm. At the same time, film-forming amine corrosion inhibitors are added to suppress electrochemical corrosion. Gaseous carbon dioxide is supplied through alloy steel pipes, with the inner coating made of polyvinylidene fluoride for impermeability treatment. Liquid carbon dioxide is supplied through high-density polyethylene pipes.

9. The method according to claim 1, characterized in that, The underground chamber can be equipped with recycling pipelines, from which carbon dioxide can be obtained when needed.

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