A carbon dioxide hydration mineralization storage device and method

Abstract

The present invention discloses a carbon dioxide hydration mineralization sequestration device and method. The device includes a reaction kettle, a gas-liquid injection unit connected to the reaction kettle, a temperature control and monitoring unit configured to control and monitor the temperature during the reaction process of the reaction kettle, a pressure control and monitoring unit configured to control and monitor the pressure during the reaction process of the reaction kettle, a visualization observation window provided on the reaction kettle, a sediment sample placement unit located inside the reaction kettle, and a data acquisition and recording unit respectively connected to the temperature control and monitoring unit and the pressure control and monitoring unit. Through the present invention, the main controlling factors and mineralization mechanism of carbon dioxide hydration mineralization can be deeply explored, the limitation of traditional carbon dioxide hydrate sequestration that only focuses on the phase equilibrium region and sediment physical properties can be broken through, and a site selection strategy based on mineral composition can be further proposed, providing theoretical and technical support for the practical application of the hydration mineralization technology.

Description

Technical Field

[0001] The present invention relates to the technical fields of geological sequestration, low-carbon, clean and environmental protection technologies, and particularly relates to a carbon dioxide hydrate mineralization sequestration device and method. Background Art

[0002] On the one hand, "emission reduction" should be carried out through means such as energy structure adjustment and technological improvement. On the other hand, "carbon sink enhancement" should be carried out through technologies such as afforestation, carbon storage, and carbon conversion. Along with human survival and industrial development, the carbon emission cannot be an absolute zero value. Therefore, it is particularly important to innovate and develop carbon sink enhancement technologies to offset this inevitable part of carbon emissions through "carbon sink enhancement". Carbon capture, utilization and storage (CCUS) refers to separating carbon dioxide from carbon emission sources, transporting it to specific locations for utilization, improving the recovery rates of resources such as groundwater, crude oil, coalbed methane, shale gas, geothermal energy, and hydrates, and carrying out sequestration isolation, which can simultaneously achieve the dual processes of "carbon emission reduction" and "carbon sink enhancement", and is regarded as one of the important pillars for future emission reduction. Among them, deep saline aquifers and submarine sediments, as the optimal and most widely distributed natural carbon reservoirs for carbon dioxide sequestration, have extremely large storage spaces and sequestration potentials. The relatively high salinity, temperature, and pressure in saline aquifers are all conducive to the conversion of carbon dioxide from a gaseous state to a supercritical state for dissolution and mineralization in the formation, so as to be stably sequestered in the formation. Carbon dioxide forms carbon dioxide hydrates in the low-temperature and high-pressure environment of marine sediments, which can also enable carbon dioxide to be stably sequestered on the seabed in the form of hydrates, achieving the effect of "carbon sink enhancement". In the prior art, carbon dioxide sequestration is mainly achieved through the following methods:

[0003] Carbon dioxide mineralization: Injecting carbon dioxide into a geological environment rich in alkaline metal ions to generate stable carbonate minerals (such as CaCO 3 、MgCO 3 ). For example, the CarbFix project in Iceland successfully achieved carbon dioxide mineralization sequestration in basalt formations. For example, the Sleipner project in Norway successfully sequestered carbon dioxide in abandoned oil and gas fields in the North Sea.

[0004] Hydrate sequestration: Forming carbon dioxide hydrates in deep-sea sediments or deep aquifers under low-temperature and high-pressure conditions.

[0005] However, these methods mainly rely on a single mechanism, lack research on the synergistic effect of hydrate formation and carbon mineralization, and existing experimental devices also lack real-time monitoring capabilities, and cannot comprehensively reveal the reaction mechanism.

[0006] It should be noted that the information disclosed in the above background art section is only for understanding the background of the present application, and thus may include information that does not constitute the prior art known to those of ordinary skill in the art. Summary of the Invention

[0007] To make up for the deficiencies of the above prior art, the present invention provides a carbon dioxide hydration mineralization sequestration device and method.

[0008] To achieve the above object, the present application adopts the following technical solutions:

[0009] In a first aspect, a carbon dioxide hydration mineralization sequestration device is provided, including a reaction kettle, a gas-liquid injection unit, a temperature control and monitoring unit, a pressure control and monitoring unit, a visualization observation window, a sediment sample placement unit, and a data acquisition and recording unit; the gas-liquid injection unit is connected to the reaction kettle for injecting gas-liquid samples into the reaction kettle; the temperature control and monitoring unit is arranged to control and monitor the temperature during the reaction process of the reaction kettle; the pressure control and monitoring unit is arranged to control and monitor the pressure during the reaction process of the reaction kettle; the visualization observation window is arranged on the reaction kettle; the sediment sample placement unit is located inside the reaction kettle for clamping sediment samples; the data acquisition and recording unit is respectively connected to the temperature control and monitoring unit and the pressure control and monitoring unit for collecting and recording the data they monitor.

[0010] Further, the reaction kettle includes a kettle body and a kettle cover, and the kettle cover is hermetically connected to the kettle body; the visualization observation window is arranged on the side of the kettle body.

[0011] Further, the pressure control and monitoring unit includes a pressurizing device and a pressure sensor; the gas-liquid injection unit includes a carbon dioxide gas cylinder, a nitrogen gas cylinder, a gas inlet and outlet valve, a gas inlet and outlet, and a liquid inlet and outlet, the gas inlet and outlet is arranged above the kettle cover, and the liquid inlet and outlet is arranged at the bottom of the kettle body; the carbon dioxide gas cylinder and the nitrogen gas cylinder are respectively communicated with the inside of the kettle body through the pressurizing device via the gas inlet and outlet valve and the gas inlet and outlet; the pressure sensor is arranged on the side of the kettle body and extends into the kettle body, and the pressure sensor is connected to the data acquisition and recording unit.

[0012] Further, the temperature control and monitoring unit includes a constant temperature water bath, a water tank, and a temperature sensor; the reaction kettle is placed in the water tank, the temperature sensor is arranged on the kettle cover and extends into the kettle body, and the constant temperature water bath is connected to the water tank to adjust the water bath temperature where the reaction kettle is located.

[0013] Further, the sediment sample placement unit includes a placement table and a gripper. The placement table is disposed inside the reaction kettle. The gripper is in the shape of a barrel with an open top. The gripper is placed on the placement table, and a plurality of holes are provided in the circumferential direction of the gripper.

[0014] Further, the carbon dioxide hydrate mineralization and storage device further includes a Raman probe and an in-situ sampling unit. The Raman probe extends into the reaction kettle to in-situ and real-time monitor the evolution of the reaction process in the reaction kettle. The Raman probe is also connected to the data acquisition and recording unit. The in-situ sampling unit is located on the side of the reaction kettle and communicates with the inside of the reaction kettle to sample the solution around the sediment sample inside the reaction kettle.

[0015] In a second aspect, a carbon dioxide hydrate mineralization and storage method is provided, which uses the carbon dioxide hydrate mineralization and storage device described in the first aspect to conduct a carbon dioxide hydrate mineralization and storage test.

[0016] Further, it includes the following steps:

[0017] (1) Clean and dry the reaction kettle, and place the sediment sample in the sediment sample placement unit;

[0018] (2) Inject an aqueous solution containing Ca 2+ , Mg 2 + ions into the reaction kettle through the gas-liquid injection unit;

[0019] (3) Pass nitrogen into the reaction kettle through the gas-liquid injection unit to remove the air in the reaction kettle, and control the pressure and temperature in the reaction kettle to reach a first predetermined value, and let it stand until no new reaction occurs between the sediment sample and the aqueous solution, so as to ensure that all subsequent chemical reactions in the reaction kettle are generated by the subsequently injected carbon dioxide;

[0020] (4) Inject liquid carbon dioxide into the reaction kettle through the gas-liquid injection unit to evacuate the nitrogen in the reaction kettle, and control the pressure and temperature in the reaction kettle to reach a second predetermined value, and continuously inject liquid carbon dioxide so that the carbon dioxide forms hydrates and mineralizes with the sediment sample;

[0021] (5) During the hydrate mineralization reaction in step (4), the temperature and pressure in the reaction kettle are monitored in real time through the temperature control and monitoring unit and the pressure control and monitoring unit and transmitted to the data acquisition and recording unit;

[0022] (6) When the pressure in the reaction kettle no longer changes, it is regarded that the reaction reaches equilibrium and the reaction ends.

[0023] Further, the method further includes at least one of the following:

[0024] Calculating the carbon dioxide sequestration amount based on the monitored temperature and pressure changes;

[0025] Sampling the solution around the sediment sample through the in-situ sampling unit at predetermined intervals, and detecting the Ca 2+ , Mg 2+ ion concentrations;

[0026] Transmitting the measured Raman peaks to the data acquisition and recording unit through a Raman probe to real-time monitor the dissolution of carbon dioxide and the formation of hydrates, and to observe in real time the formation and structural evolution of carbon dioxide hydrates and carbonate minerals;

[0027] Detecting the weight and XRD of the sediment sample after the reaction ends.

[0028] Further, the sediment sample in step (1) contains feldspar minerals;

[0029] In step (4), first continuously inject a small amount of liquid carbon dioxide. After observing the formation of a hydrate cover layer above the sediment sample through the visualization observation window, then continuously inject a large amount of liquid carbon dioxide. Utilize the mineral dissolution and ion release in the sediment sample combined with the bicarbonate ions generated by the dissolution of carbon dioxide to achieve carbon dioxide mineral sequestration, forming a dual sequestration of a hydrate cover layer plus carbon dioxide mineralization.

[0030] The present invention has the following advantages:

[0031] 1. The carbon dioxide hydrate mineral sequestration device and method of the present invention can simulate the synergistic sequestration of carbon dioxide hydrate mineralization. By injecting carbon dioxide into a geological environment rich in alkaline metal ions (such as , ), the synergistic effect of carbon dioxide hydrate formation and carbon dioxide mineralization is utilized to greatly improve the carbon dioxide sequestration amount and long-term stability, providing a new means for offshore carbon dioxide sequestration.

[0032] 2. Through the temperature control and monitoring unit and the pressure control and monitoring unit, the temperature and pressure inside the reaction kettle body can be ensured to be constant, simulating the temperature and pressure environment of the actual seabed sediment layer, and the situation of the carbon dioxide hydrate mineralization process in the reaction kettle can be monitored.

[0033] 3. In the preferred solution, the in-situ sampling unit can monitor the dynamic changes of ion concentrations over reaction time, so as to clarify the changes in the chemical properties of the aqueous solution during the reaction process and determine the reaction termination time.

[0034] 4. In a preferred embodiment, the solubility of carbon dioxide can be in-situ monitored through a Raman probe, thereby quantifying the dissolution amount and diffusion coefficient of carbon dioxide, and the formation and structural evolution of carbon dioxide hydrate and carbonate minerals can be observed in real time.

[0035] 5. Through the visualization observation window, the formation of hydrate inside the reactor and the erosion of sediment samples can be observed in real time, and the liquid level height inside the system after each in-situ sampling can be observed, clarifying the immersion time of sediment samples at different heights in the solution, providing a basis for the selection of sampling points for subsequent mineral tests.

[0036] 6. Breaking through the limitation of traditional carbon dioxide hydrate storage that only focuses on the phase equilibrium region and sediment physical properties, a siting strategy based on mineral composition is further proposed. Sediment samples containing feldspar minerals are preferably selected for hydrated mineralization storage to further increase the storage amount. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 FIG. 12 is a schematic structural diagram of the carbon dioxide hydrated mineralization storage device in Embodiment 1 of the present invention;

[0038] Figure 2 FIG. 16 is a cross-sectional view of the reactor in Embodiment 1 of the present invention;

[0039] Figure 3 FIG. 20 is a flow chart of the carbon dioxide storage test in Embodiment 2 and Comparative Example 1 of the present invention;

[0040] Figure 4 FIG. 24 is the morphological evolution during the hydrated mineralization process in Embodiment 2 of the present invention;

[0041] Figure 5 FIG. 28 is the difference in surface porosity of the sediment sample before and after the reaction in Embodiment 2 of the present invention;

[0042] Figure 6 FIG. 32 is the SEM results of four parts of the sediment sample after the reaction in Embodiment 2 of the present invention;

[0043] Figure 7 FIG. 36 is a schematic diagram of the comparison of carbon dioxide storage amounts in Embodiment 2 and Comparative Example 1 of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0044] The following is a detailed description of the embodiments of the present invention. It should be emphasized that the following description is merely exemplary and is not intended to limit the scope and application of the present invention. Without conflict, the embodiments and features in the present application can be combined with each other.

[0045] In the research, the inventor found that during the process of injecting carbon dioxide into the marine sediment layer, not only hydrates are formed, but carbon dioxide also reacts with the minerals in the seabed sediment layer and is permanently stored in the formation in the form of carbonate minerals, achieving the synergistic sequestration effect of carbon dioxide hydrate and carbon dioxide mineralization. This process is called Hydrate-based Carbon Mineralization. Hydrate-based Carbon Mineralization combines carbon dioxide sequestration through carbon dioxide hydrate formation and carbon dioxide water mineralization. Its core principle is to inject carbon dioxide into the geological environment of formation water rich in alkaline metal minerals and alkaline metal ions (such as , ), and utilize the synergistic effect of hydrate formation and mineralization reactions to achieve long-term and stable sequestration of carbon dioxide. Through this new method of carbon dioxide sequestration by hydrate-based carbon mineralization, the problem that a large amount of gaseous, liquid-phase, and dissolved-phase carbon dioxide in carbon dioxide hydrate sequestration has not been converted into a stable hydrate phase can be solved, and the abundant alkali metal minerals in the formation can be fully utilized to convert carbon dioxide into long-term and stable carbonate minerals. The formation of the hydrate lattice significantly increases the ion concentration of the fluid in the pores, and the formation water rich in alkaline ions provides a favorable chemical environment for mineralization, realizing the synergistic effect of carbon dioxide mineralization sequestration and hydrate sequestration, and improving the sequestration amount and sequestration efficiency of carbon dioxide. Moreover, hydrate-based carbon mineralization sequestration has a high mineral conversion rate and high sequestration stability. In the marine sediment layer rich in alkaline minerals, the carbon dioxide mineralization conversion rate can reach more than 55%, the stable period of the carbon dioxide hydrate phase > 1000 years, and the mineral phase > 10000 years. This synergistic sequestration mode provides a solution with both engineering feasibility and sequestration efficiency for addressing climate change, and provides a new path for offshore carbon dioxide sequestration.

[0046] Therefore, the present invention proposes a method and device that can be used for carbon dioxide hydrate-based carbon mineralization sequestration tests, providing theoretical and technical support for the practical application of hydrate-based carbon mineralization technology.

[0047] The specific implementation mode of the present invention provides a carbon dioxide hydration mineralization and storage device, including a reaction kettle, a gas-liquid injection unit, a temperature control and monitoring unit, a pressure control and monitoring unit, a visualization observation window, a sediment sample placement unit, and a data acquisition and recording unit; the gas-liquid injection unit is connected to the reaction kettle for injecting gas-liquid samples into the reaction kettle; the temperature control and monitoring unit is arranged to control and monitor the temperature during the reaction process of the reaction kettle; the pressure control and monitoring unit is arranged to control and monitor the pressure during the reaction process of the reaction kettle; the visualization observation window is arranged on the reaction kettle; the sediment sample placement unit is located inside the reaction kettle for clamping sediment samples; the data acquisition and recording unit is respectively connected to the temperature control and monitoring unit and the pressure control and monitoring unit for collecting and recording the data they monitor.

[0048] In some embodiments, the reaction kettle includes a kettle body and a kettle cover, and the kettle cover is hermetically connected to the kettle body; the visualization observation window is arranged on the side of the kettle body.

[0049] In some embodiments, the pressure control and monitoring unit includes a pressurizing device and a pressure sensor; the gas-liquid injection unit includes a carbon dioxide gas cylinder, a nitrogen gas cylinder, a gas inlet and outlet valve, a gas inlet and outlet, and a liquid inlet and outlet. The gas inlet and outlet is arranged above the kettle cover, and the liquid inlet and outlet is arranged at the bottom of the kettle body; the carbon dioxide gas cylinder and the nitrogen gas cylinder are respectively communicated with the inside of the kettle body through the pressurizing device via the gas inlet and outlet valve and the gas inlet and outlet; the pressure sensor is arranged on the side of the kettle body and extends into the kettle body, and the pressure sensor is connected to the data acquisition and recording unit.

[0050] In some embodiments, the temperature control and monitoring unit includes a constant temperature water bath, a water tank, and a temperature sensor; the reaction kettle is placed in the water tank, the temperature sensor is arranged on the kettle cover and extends into the kettle body, and the constant temperature water bath is connected to the water tank to adjust the water bath temperature where the reaction kettle is located.

[0051] In some embodiments, the sediment sample placement unit includes a placement table and a clamp. The placement table is arranged inside the reaction kettle. The clamp is in the shape of a barrel with an open top. The clamp is placed on the placement table, and several holes are arranged in the circumferential direction of the clamp.

[0052] In some embodiments, the carbon dioxide hydrate mineralization and storage device further includes a Raman probe and an in-situ sampling unit; the Raman probe extends into the interior of the reaction kettle to in-situ and real-time monitor the evolution of the reaction process in the reaction kettle, and the Raman probe is also connected to the data acquisition and recording unit; the in-situ sampling unit is located on the side of the reaction kettle and communicates with the interior of the reaction kettle to sample the solution around the sediment sample inside the reaction kettle.

[0053] The specific embodiment of the present invention also provides a carbon dioxide hydrate mineralization and storage method, which uses the carbon dioxide hydrate mineralization and storage device as described above to conduct a carbon dioxide hydrate mineralization and storage test.

[0054] In some embodiments, the carbon dioxide hydrate mineralization and storage method includes the following steps:

[0055] (1) Clean and dry the reaction kettle, and place the sediment sample in the sediment sample placement unit;

[0056] (2) Inject an aqueous solution containing Ca 2+ , Mg 2 + ions into the reaction kettle through the gas-liquid injection unit;

[0057] (3) Pass nitrogen into the reaction kettle through the gas-liquid injection unit to exclude the air in the reaction kettle, and control the pressure and temperature in the reaction kettle to reach a first predetermined value, and let it stand until no new reaction occurs between the sediment sample and the aqueous solution, so as to ensure that all subsequent chemical reactions in the reaction kettle are generated by the subsequently injected carbon dioxide; in this step (3), by standing, the sediment sample and the aqueous solution are balanced, so that the calculated storage amount after injecting liquid carbon dioxide subsequently is the true carbon dioxide storage amount.

[0058] (4) Inject liquid carbon dioxide into the reaction kettle through the gas-liquid injection unit to evacuate the nitrogen in the reaction kettle, and control the pressure and temperature in the reaction kettle to reach a second predetermined value, and continuously inject liquid carbon dioxide so that the carbon dioxide forms hydrates and mineralizes with the sediment sample;

[0059] (5) During the hydrate mineralization reaction in step (4), the temperature and pressure in the reaction kettle are real-time monitored through the temperature control and monitoring unit and the pressure control and monitoring unit and transmitted to the data acquisition and recording unit;

[0060] (6) When the pressure in the reaction kettle no longer changes, it is regarded that the reaction reaches equilibrium and the reaction ends.

[0061] In some embodiments, the method further includes at least one of the following:

[0062] Calculating the carbon dioxide sequestration amount based on the monitored temperature and pressure changes;

[0063] Sampling the solution around the sediment sample through the in-situ sampling unit at predetermined intervals, and detecting the Ca 2+ , Mg 2+ ion concentrations;

[0064] Transmitting the measured Raman peaks to the data acquisition and recording unit through a Raman probe to monitor the dissolution of carbon dioxide and the formation of hydrates in real time, and observing the formation and structural evolution of carbon dioxide hydrates and carbonate minerals in real time;

[0065] Detecting the weight and XRD of the sediment sample after the reaction ends.

[0066] In some embodiments, the sediment sample in step (1) contains feldspar minerals. The feldspar minerals include, but are not limited to, plagioclase.

[0067] In some embodiments, in step (4), liquid carbon dioxide is continuously injected in small amounts first (the first stage). After observing the formation of a hydrate cover layer above the sediment sample through the visualization observation window, liquid carbon dioxide is continuously injected in large amounts (the second stage) (that is, the amount of liquid carbon dioxide continuously injected in the second stage is greater than that in the first stage). The mineral dissolution and ion release in the sediment sample are combined with the bicarbonate ions generated by the dissolution of carbon dioxide to achieve carbon dioxide mineral sequestration, forming a dual sequestration of a hydrate cover layer plus carbon dioxide mineralization. Among them, during the process of continuously injecting liquid carbon dioxide in small amounts in the early stage, the formation of carbon dioxide hydrates and the mineral dissolution and ion release of the sediment sample mainly occur. During the formation of carbon dioxide hydrates, the hydrates climb upward and form a dense hydrate cover layer above the sediment sample, inhibiting the upward migration of carbon dioxide. After observing the formation of the hydrate cover layer, liquid carbon dioxide is continuously injected in large amounts, mainly using the mineral dissolution and ion release in the sediment sample combined with the bicarbonate ions generated by the dissolution of carbon dioxide to achieve carbon dioxide mineral sequestration, thereby forming a collaborative sequestration of an upper hydrate cover layer and a lower mineralized layer, greatly improving the carbon dioxide sequestration amount and sequestration efficiency.

[0068] The present invention will be further described below through specific embodiments. Example 1

[0069] As Figure 1 and 2As shown, the carbon dioxide hydrate mineralization and storage device in this example can perform real-time analysis of ion concentrations during the carbon dioxide hydrate mineralization process through an in-situ sampling unit, and is equipped with a pressure sensor, a temperature sensor, and a Raman probe to achieve real-time detection of reaction kinetic parameters and carbon dioxide properties during the reaction process. The device includes a reaction kettle, a gas-liquid injection unit, a temperature control and monitoring unit, a pressure control and monitoring unit, a visualization observation window 17, a Raman probe 9, a sediment sample placement unit, an in-situ sampling unit 13, and a data acquisition and recording unit. The reaction kettle can simulate the low-temperature and high-pressure environment of carbon dioxide hydrate mineralization reaction using submarine sediments, and can withstand the corrosion of carbon dioxide at the same time. It includes a kettle body 5 and a kettle lid 18, and the kettle lid 18 is hermetically connected to the kettle body 5. For example, the kettle lid 18 can be rotated to the lowest position by threading to be sealed with a gasket and the kettle body. The visualization observation window 17 and the in-situ sampling unit 13 are both arranged on the side of the kettle body 5. The visualization observation window 17 can be sealed with a screw and a gasket, and the morphology of hydrate formation and the mineralization process during the hydrate mineralization process can be observed through the visualization observation window 17 to clarify the spatial distribution of the formation and mineralization of carbon dioxide hydrate during the hydrate mineralization process. The in-situ sampling unit 13 is used to sample the solution around the sediment sample inside the reaction kettle, and the ion concentration of the sample can be tested by ICP and a pH meter to clarify the impact of hydrate mineralization on the chemical environment of formation water.

[0070] The Raman probe 9 is arranged on the kettle lid 18 and extends into the kettle body 5 to in-situ and real-time monitor the evolution of the reaction process in the reaction kettle, such as monitoring the dissolution of carbon dioxide and the formation of hydrates, and real-time observing the formation and structural evolution of carbon dioxide hydrates and carbonate minerals, etc.

[0071] The pressure control and monitoring unit is arranged to control and monitor the pressure during the reaction process of the reaction kettle to ensure that the reaction pressure is the pressure of the actual formation, including a pressurization device 3 and a pressure sensor 7. The gas-liquid injection unit is connected to the reaction kettle and is used to inject gas-liquid samples into the reaction kettle, including a carbon dioxide gas cylinder 1, a nitrogen gas cylinder 2, a gas inlet and outlet valve 6, a gas inlet and outlet 21, and a liquid inlet and outlet 19. The gas inlet and outlet 21 is arranged above the kettle lid 18, and the liquid inlet and outlet 19 is arranged at the bottom of the kettle body 5. The carbon dioxide gas cylinder 1 and the nitrogen gas cylinder 2 are respectively connected to the inside of the kettle body 5 through the pressurization device 3 via the gas inlet and outlet valve 6 and the gas inlet and outlet 21 by a pipeline 4. The pressure sensor 7 is arranged on the side of the kettle body 5 and extends into the kettle body 5, and the pressure sensor 7 is connected to the data acquisition and recording unit.

[0072] The temperature control and monitoring unit is arranged to control and monitor the temperature during the reaction process of the reactor, and includes a constant temperature water bath 10, a water tank 11 and a temperature sensor 8. The reactor is placed in the water tank 11, and the temperature sensor 8 is arranged on the reactor cover 18 and extends into the reactor body 5. The constant temperature water bath 10 is connected to the water tank 11 to adjust the water bath temperature where the reactor is located, so as to restore the real temperature environment of the seabed.

[0073] The sediment sample placement unit is located inside the reactor and is used to hold the sediment sample, and includes a placement table 12 and a gripper 14. The placement table 12 is located on the bottom surface inside the reactor body 5. The gripper 14 is in the shape of a barrel with an open upper part. The gripper 14 is placed on the placement table 12. A number of holes are arranged in the circumferential direction of the gripper 14. During the experiment, the actual seabed sediment sample (also referred to as the sediment sample in this article) is placed in the gripper 14. The gripper 14 allows the exchange of Ca 2+ , Mg 2+ ions between the sediment sample and the solution outside the gripper 14. In this example, small holes with a diameter of 1 mm are distributed in the circumferential direction of the gripper 14 (not shown).

[0074] The data acquisition and recording unit includes a data transmission device 20 and a computer 16. The data monitored by the pressure sensor 7, the temperature sensor 8 and the Raman probe 9 are connected to the computer 16 through the data transmission device 20 and recorded by the computer 16.

[0075] The following describes the carbon dioxide sequestration test. Figure 3 It is a flow chart of the carbon dioxide sequestration method, mainly including the following steps: 1. Target area selection and sample selection; 2. Pre-test of reaction samples; 3. Conduct two groups of experiments for carbon dioxide hydrate sequestration and carbon dioxide hydro-mineralization respectively, and compare to obtain the effect of hydro-mineralization on promoting carbon dioxide sequestration; 4. Test the samples after the experiment, including the weight of the samples after the reaction, the microscopic structure of the minerals, the ionic concentration composition of the solution after the reaction, and the mineral composition of the samples after the reaction.

[0076] Example 2 (Hydro-mineralization test)

[0077] The carbon dioxide hydro-mineralization sequestration method in this example is carried out using the carbon dioxide hydro-mineralization sequestration device of Example 1, as Figure 3 shown, and includes the following steps:

[0078] (1) Conduct a pre-test on the sediment sample to measure its parameters such as weight and mineral composition. Then clean and dry the reactor, and place the sediment sample in the gripper 14 and place it on the placement table 12 inside the reactor;

[0079] In this example, Well W17 in the Shenhu area of the Baiyun Sag in the Pearl River Estuary Basin of the South China Sea was taken as the actual target area, and carbon dioxide hydration mineralization experiments were carried out using actual sediment cores (sediment samples).

[0080] Properties of the sediment samples in this example: The whole-rock XRD analysis and testing of the sediment samples were carried out to determine the mineral composition (volume fraction) of the sediment samples as follows: quartz 29.2%, clay minerals 38.2%, calcite 20.4%, potassium feldspar 6.1%, plagioclase 4.3%, and dolomite 1.8%. Among them, quartz, as the main brittle mineral, its rigid framework effect is beneficial to the development and preservation of the pore system. The component analysis of clay minerals shows (volume fraction of the total amount of clay minerals): illite-smectite mixed layer (I / S) 50% (montmorillonite layer accounts for 54%), illite 27%, kaolinite 11%, and chlorite 12%.

[0081] (2) Inject an aqueous solution with the same composition as the actual sediment formation water prepared into the reaction kettle through the liquid inlet and outlet 19. Among them, the concentration of Ca 2+ is 1382.4 mg / L, the concentration of Mg 2+ ions is 112.1 mg / L, the concentration of Na + ions is 344.9 mg / L, and the concentration of Cl - ions is 3300.4 mg / L;

[0082] (3) Pass nitrogen into the reaction kettle through the nitrogen gas cylinder 2 and the pressurizing device 3 to remove the air in the reaction kettle and pressurize it. Place the reaction kettle in the water tank 11, and set the desired test temperature on the constant temperature water bath 10. When the pressure and temperature in the reaction kettle reach the first predetermined value (where the pressure is 6 MPa and the temperature is 15 °C), let it stand for 24 hours until no new reaction occurs between the sediment sample and the aqueous solution, so as to ensure that all subsequent chemical reactions in the reaction kettle are generated by the subsequently injected carbon dioxide;

[0083] (4) Inject liquid carbon dioxide into the reaction kettle through the carbon dioxide gas cylinder 1, the pressurization device 3, the gas inlet and outlet valve 6, and the gas inlet and outlet 21 to evacuate the nitrogen in the reaction kettle and increase the pressure until the test pressure is reached. Set the test temperature through the constant temperature water bath 10, and cool down to carry out the carbon dioxide hydration mineralization reaction (wherein, the test pressure is 6 MPa and the test temperature is 2 °C), so that the carbon dioxide forms hydrates and mineralizes with the sediment sample; wherein, in this step, first continuously inject a small amount of liquid carbon dioxide. When a hydrate cover layer is formed above the sediment sample observed from the visual observation window, then continuously inject a large amount of liquid carbon dioxide. Utilize the dissolution of minerals in the sediment sample and the release of alkaline ions to combine with the bicarbonate ions generated by the dissolution of carbon dioxide to achieve carbon dioxide mineralization and storage, forming a double storage of hydrate cover layer plus carbon dioxide mineralization.

[0084] As Figure 4 shown, it is the morphological evolution of the hydrate mineralization process. Among them, t n represents the time when the hydrate starts to nucleate. After injecting liquid carbon dioxide and cooling down, the phenomenon of carbon dioxide hydrate growing along the wall occurs (a hydrate cover layer is formed above the sediment sample), while the sediment sample is at the lower part of the reaction kettle. The formation of hydrates consumes water and increases the concentration of alkaline ions in the solution, further accelerating the mineralization reaction.

[0085] (5) During the hydration mineralization reaction in step (4), sample the solution around the sediment sample through the in-situ sampling unit 13 at predetermined intervals, and perform Ca 2+ , Mg 2+ ion concentration detection; transmit the measured Raman peaks to the data acquisition and recording unit through the Raman probe to real-time monitor the evolution of the reaction process in the reaction kettle (specifically, monitor the dissolution of carbon dioxide and the formation of hydrates, and real-time observe the formation and structural evolution of carbon dioxide hydrates and carbonate minerals); real-time monitor the temperature and pressure in the reaction kettle through the temperature control and monitoring unit and the pressure control and monitoring unit and transmit them to the data acquisition and recording unit;

[0086] (6) When the pressure in the reaction kettle no longer changes, it is regarded that the reaction reaches equilibrium and the reaction ends. Calculate the carbon dioxide storage amount through the monitored temperature and pressure changes, and detect the weight and XRD of the sediment sample after the reaction ends to obtain the mineral ratio of carbon dioxide mineralization.

[0087] In this example, as Figure 5 and 6As shown, obvious carbonate minerals were observed under the microscope after the reaction, which were characterized as calcite minerals in the energy spectrum. At the same time, obvious dissolution pores were generated on the surface of the sediment sample, and the surface porosity of the sample increased with the increase of the reaction time, providing pore space for the growth of hydrates. This is due to mineral dissolution in an acidic environment (as Figure 5 shown, before the reaction, the porosity of the sediment sample was 2.339%, and after the reaction, the porosity of the sediment sample was 6.734%). The results of XRD showed that the content of plagioclase decreased from 4.3% to 0%, while the contents of calcite and dolomite both increased slightly, being 22.5% and 3.2% respectively. This indicates that the dissolution of feldspar minerals provided an ionic environment for the formation of carbonate minerals in the solution, and the HCO 2 dissolved from CO 3 - reacted with Ca 2+ , Mg 2+ ions to form calcite and dolomite.

[0088] In this example, the calculation of the sequestration amount refers to the method in Chinese Patent Application CN 116148303 A. Among them, the density of the aqueous solution of the present invention is approximately equal to the density of pure water, and the sequestration amount of carbon dioxide by hydrate mineralization reaches 55.11 (the volume of carbon dioxide stored per unit system under standard conditions, that is, the ratio of the sequestration volume V CO2 of carbon dioxide to the volume V 水 of the aqueous solution is 55.11).

[0089] Comparative Example 1 (Hydrate Formation Experiment)

[0090] As Figure 3 shown, the difference between Comparative Example 1 and Example 2 is that instead of placing a sediment sample in the holder 14, quartz sand that does not react with carbon dioxide is placed. The particle size and porosity of the quartz sand before the experiment are the same as those of the sediment sample. The other experimental procedures are the same as those in Example 2. In this Comparative Example 1, there is no hydrate mineralization process. Similarly, the calculation of the sequestration amount in Comparative Example 1 refers to the method in Chinese Patent Application CN 116148303 A.

[0091] The sequestration amounts of carbon dioxide by hydrate mineralization in Example 2 and by hydrate sequestration in Comparative Example 1 (expressed as the ratio of the sequestration volume V CO2 of carbon dioxide to the volume V 水 of the aqueous solution) are as Figure 7 shown. By comparing Example 2 and Comparative Example 1, it can be seen that hydrate mineralization in Example 2 can greatly promote the effect of carbon dioxide sequestration and increase the sequestration amount. From the calculation results of gas consumption, it can be seen that compared with only considering the sequestration of carbon dioxide hydrate, the sequestration amount of carbon dioxide by hydrate mineralization increases by about 18%.

[0092] As can be seen from the above embodiments, the method and device for carbon dioxide hydrate mineralization and storage of the present invention aim to achieve efficient and stable storage of carbon dioxide by combining two mechanisms of carbon dioxide hydrate formation and carbon dioxide mineralization. Its advantages include:

[0093] 1. Synergistic storage of hydrate mineralization: The reaction kettle of the present invention is a multiphase reaction kettle that can simultaneously carry out multiple reactions (such as hydrate formation, carbon dioxide mineralization, mineral dissolution, etc.), further improving the experimental efficiency. By injecting carbon dioxide into a geological environment rich in alkaline metal ions (such as , ), the synergistic effect of hydrate formation and mineralization reactions is utilized to significantly increase the storage capacity and long-term stability of carbon dioxide, and improve the storage efficiency of carbon dioxide.

[0094] 2. In-situ monitoring and real-time analysis: It can monitor the dynamic changes of temperature, pressure, ion concentration, and carbon dioxide dissolution and diffusion during the reaction process in real time. Combining with in-situ Raman spectroscopy technology, the dissolution of carbon dioxide and the formation of hydrates are quantified, and the formation and structural evolution of hydrates and carbonate minerals are observed in real time.

[0095] 3. Precise simulation of the actual geological environment: By means of a constant temperature water bath and a gas pressurization device, the low-temperature and high-pressure environment of the submarine sediment layer is simulated to ensure that the experimental conditions are consistent with the actual geological conditions and reliable and accurate experimental results are obtained.

[0096] 4. In-situ sampling and mineralogical analysis: The dynamic changes of ion concentration over time are monitored through the in-situ sampling unit. Combining with the mineralogical analysis after the reaction, the main control factors and mineralization mechanisms of carbon dioxide hydrate mineralization are deeply explored.

[0097] 5. Multi-scale simulation: The above-mentioned automated control unit introduced in the device and method of the present invention realizes the automated operation and data recording of the experimental process, reduces human errors, and through monitoring the dynamic changes during the reaction process, combining numerical simulation and experimental research, realizes multi-scale simulation from micro to macro, and comprehensively reveals the reaction mechanism of carbon dioxide hydrate mineralization.

[0098] 6. Break through the limitations of traditional carbon dioxide hydrate storage that only focuses on the phase equilibrium region and sediment physical properties, and further proposes a siting strategy based on mineral composition. It is preferred to select sediment samples containing feldspar minerals for hydrate mineralization storage to further increase the storage capacity.

[0099] The device and method of the present invention can be applied to the following fields:

[0100] 1. Deep-sea carbon dioxide storage: Achieve long-term and stable storage of carbon dioxide in deep-sea sediments.

[0101] 2. Sequestration of offshore abandoned oil and gas fields: Utilize the geological conditions of abandoned oil and gas fields to achieve efficient sequestration of carbon dioxide.

[0102] 3. Direct sequestration of ship flue gas: Collect carbon dioxide through carbon capture facilities on ships and achieve hydrated mineralization sequestration of carbon dioxide.

[0103] 4. Industrial waste gas treatment: Applied to the capture and sequestration of carbon dioxide in industrial waste gas to reduce carbon emissions.

[0104] The above content is a further detailed description of the present invention in combination with specific / preferred embodiments, and it cannot be determined that the specific implementation of the present invention is only limited to these descriptions. For those of ordinary skill in the technical field to which the present invention pertains, without departing from the concept of the present invention, several alternatives or modifications can be made to these described embodiments, and these alternative or modified forms should all be regarded as falling within the protection scope of the present invention. In the description of this specification, the description with reference to terms such as "one embodiment", "some embodiments", "preferred embodiment", "example", "specific example", or "some examples" means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. Without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples. Although the embodiments of the present invention and their advantages have been described in detail, it should be understood that various changes, substitutions, and alterations can be made herein without departing from the scope of protection of the patent application.

Claims

1. A method for storing carbon dioxide by hydration mineralization, characterized in that: A carbon dioxide hydration mineralization storage device is used to carry out a carbon dioxide hydration mineralization storage test, wherein the carbon dioxide hydration mineralization storage device comprises a reactor, a gas-liquid injection unit, a temperature control and monitoring unit, a pressure control and monitoring unit, a visual observation window, a sediment sample placement unit, a data acquisition and recording unit, and a Raman probe; the gas-liquid injection unit is connected to the reactor and is used to inject gas-liquid samples into the reactor; the temperature control and monitoring unit is configured to control and monitor the temperature during the reaction of the reactor; the pressure control and monitoring unit is configured to control and monitor the pressure during the reaction of the reactor; the visual observation window is arranged on the reactor; the sediment sample placement unit is located in the reactor and is used to clamp the sediment sample; the Raman probe extends into the reactor, and the Raman probe is also connected to the data acquisition and recording unit; the data acquisition and recording unit is respectively connected to the temperature control and monitoring unit and the pressure control and monitoring unit to collect and record the data monitored by them; The carbon dioxide hydration mineralization storage method comprises the following steps: (1) The reactor is cleaned and dried, and a sediment sample is placed in the sediment sample placement unit, wherein the sediment sample is an actual sediment core rock from Well W17 in the Shenhu Sea area of ​​the Baiyun Sag, the Pearl River Mouth Basin, South China Sea; (2) Injecting an aqueous solution into the reactor through the gas-liquid injection unit, wherein the aqueous solution is an aqueous solution having the same composition as the actual sediment formation water, containing Ca 2+ ,Mg 2+ ion; (3) introducing nitrogen into the reactor through the gas-liquid injection unit to remove the air in the reactor, and controlling the pressure and temperature in the reactor to reach a first predetermined value, and standing until the sediment sample and the aqueous solution no longer produce new reactions, so as to ensure that all subsequent chemical reactions in the reactor are produced by the subsequently injected carbon dioxide; (4) injecting liquid carbon dioxide into the reactor through the gas-liquid injection unit to exhaust the nitrogen in the reactor, and controlling the pressure and temperature in the reactor to reach a second predetermined value, and continuously injecting liquid carbon dioxide so that the carbon dioxide generates hydrates and is mineralized with the sediment sample; wherein the Raman peak measured is transmitted to the data acquisition and recording unit through the Raman probe to monitor the dissolution of carbon dioxide and the generation of hydrates in real time, and to observe the formation and structural evolution of carbon dioxide hydrates and carbonate minerals in real time, and the continuous injection of liquid carbon dioxide is: first continuously injecting a small amount of liquid carbon dioxide, and when a hydrate cap layer is formed above the sediment sample, continuously injecting a large amount of liquid carbon dioxide, and utilizing the mineral dissolution and ion release in the sediment sample combined with the bicarbonate ions generated by the dissolution of carbon dioxide to achieve mineralization and storage of carbon dioxide, thereby forming a synergistic storage of the upper hydrate cap layer and the lower carbon dioxide mineralized mineralized layer; (5) During the hydration mineralization reaction of step (4), the temperature and pressure in the reactor are monitored in real time by the temperature control and monitoring unit and the pressure control and monitoring unit and transmitted to the data acquisition and recording unit; (6) When the pressure in the reactor no longer changes, the reaction is considered to have reached equilibrium and the reaction is over; (7) The amount of CO2 stored in the hydrated mineralized state is calculated by monitoring the changes in temperature and pressure, and the proportion of CO2 mineralized minerals is determined by weight and XRD tests of sediment samples after the reaction.

2. The method for storing carbon dioxide by hydration mineralization according to claim 1, characterized in that: The carbon dioxide hydration mineralization storage device further includes an in-situ sampling unit, and the in-situ sampling unit is located on the side of the reactor and communicates with the interior of the reactor. The method further includes: The solution around the sediment sample is sampled at predetermined intervals by an in-situ sampling unit, and Ca 2+ ,Mg 2+ Ion concentration detection.

3. The method for storing carbon dioxide by hydration mineralization according to claim 1, characterized in that: The reactor comprises a reactor body and a reactor cover, wherein the reactor cover is sealed and connected to the reactor body; and the visual observation window is arranged on the side of the reactor body.

4. The method for storing carbon dioxide by hydration mineralization according to claim 3, characterized in that: The pressure control and monitoring unit includes a pressurizing device and a pressure sensor; the gas-liquid injection unit includes a carbon dioxide gas cylinder, a nitrogen gas cylinder, a gas inlet and outlet valve, a gas inlet and outlet, and a liquid inlet and outlet, the gas inlet and outlet are arranged above the kettle cover, and the liquid inlet and outlet are arranged at the bottom of the kettle body; the carbon dioxide gas cylinder and the nitrogen gas cylinder are connected to the interior of the kettle body through the pressurizing device via the gas inlet and outlet valve and the gas inlet and outlet; the pressure sensor is arranged on the side of the kettle body and extends into the interior of the kettle body, and the pressure sensor is connected to the data acquisition and recording unit.

5. The method for storing carbon dioxide by hydration mineralization according to claim 3, characterized in that: The temperature control and monitoring unit includes a constant temperature water bath, a water tank and a temperature sensor; the reactor is placed in the water tank, the temperature sensor is arranged on the reactor cover and extends into the interior of the reactor body, and the constant temperature water bath is connected to the water tank to adjust the water bath temperature of the reactor.

6. The method for storing carbon dioxide by hydration mineralization according to claim 1, characterized in that: The sediment sample placement unit comprises a placement table and a clamp, wherein the placement table is arranged inside the reactor, and the clamp is in the shape of a barrel with an open top, and the clamp is placed on the placement table, and a plurality of holes are arranged on the circumference of the clamp.

Images