A device and method for storing carbon dioxide hydration mineralization

Abstract

The present invention discloses a carbon dioxide hydration mineralization storage device and method. The device includes a reactor, a gas-liquid injection unit connected to the reactor, a temperature control and monitoring unit configured to control and monitor the temperature of the reactor during the reaction process, a pressure control and monitoring unit configured to control and monitor the pressure of the reactor during the reaction process, a visual observation window disposed on the reactor, a sediment sample placement unit located in the reactor, 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 mechanisms of carbon dioxide hydration mineralization can be deeply explored, breaking through the limitation that traditional carbon dioxide hydrate storage only focuses on phase equilibrium zones and sediment physical properties, and further proposing a site selection strategy based on mineral composition, providing theoretical and technical support for the practical application of hydration mineralization technology.

Description

Technical Field

[0001] The present invention relates to The field of geological storage, low-carbon clean environmental protection technology, and particularly relates to a carbon dioxide hydration mineralization storage device and method. Background Art

[0002] On the one hand, we need to adjust the energy structure and improve technology to reduce emissions, and on the other hand, we need to increase carbon sinks through afforestation, carbon storage, carbon conversion and other technologies. With human survival and industrial development, carbon emissions cannot be absolutely zero. Therefore, it is particularly important to offset this inevitable carbon emission through "increasing carbon sinks". 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 rate of resources such as groundwater, crude oil, coalbed methane, shale gas, geothermal energy, and hydrates, and sealing and isolating it. It can achieve the dual process of "carbon emission reduction" and "carbon sink enhancement" at the same time, and is regarded as one of the important pillars of future emission reduction. Among them, deep saline water layers and seabed sediments are the best and most widely distributed natural carbon reservoirs for carbon dioxide sequestration, with huge storage space and sequestration potential. The higher mineralization, temperature and pressure in the saline layer are conducive to the conversion of carbon dioxide from gas to supercritical state, dissolution and mineralization in the stratum, and thus stable storage in the stratum. Carbon dioxide forms carbon dioxide hydrates in the low temperature and high pressure environment of marine sediments, which can also make carbon dioxide stable and sealed in the seabed in the form of hydrates for a long time, achieving the effect of "sink enhancement". In the prior art, carbon dioxide storage is mainly achieved in the following ways: Carbon dioxide mineralization: Injecting carbon dioxide into a geological environment rich in alkaline metal ions to generate stable carbonate minerals (such as CaCO3, MgCO3). For example, Iceland's CarbFix project successfully achieved carbon dioxide mineralization storage in basalt formations. For example, Norway's Sleipner project successfully stored carbon dioxide in abandoned oil and gas fields in the North Sea.

[0003] Hydrate storage: Carbon dioxide hydrates are formed in deep-sea sediments or deep aquifers using low temperature and high pressure conditions.

[0004] However, these methods mainly rely on a single mechanism and lack research on the synergistic effect of hydrate formation and carbon mineralization. Existing experimental equipment also lacks real-time monitoring capabilities and cannot fully reveal the reaction mechanism.

[0005] It should be noted that the information disclosed in the above background technology section is only used for understanding the background of the present application, and therefore may include information that does not constitute prior art known to ordinary technicians in the field. Summary of the invention

[0006] In order to make up for the deficiencies of the above-mentioned prior art, the present invention provides a carbon dioxide hydration mineralization storage device and method.

[0007] In order to achieve the above objectives, this application adopts the following technical solutions: In the first aspect, a carbon dioxide hydration mineralization storage device is provided, comprising 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, and a data acquisition and recording unit; 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 process of the reactor; the pressure control and monitoring unit is configured to control and monitor the pressure during the reaction process 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 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 monitored by them.

[0008] Furthermore, 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.

[0009] Furthermore, the pressure control and monitoring unit includes a booster 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 booster 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.

[0010] Furthermore, 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.

[0011] Furthermore, the sediment sample placement unit includes a placement table and a clamp, the placement table is arranged inside the reactor, the clamp is a barrel-shaped clamp with an open top, the clamp is placed on the placement table, and a plurality of holes are arranged on the circumference of the clamp.

[0012] Furthermore, the carbon dioxide hydration mineralization storage device also includes a Raman probe and an in-situ sampling unit; the Raman probe extends into the interior of the reactor to monitor the evolution of the reaction process in the reactor in real time and in situ, 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 reactor and connected to the interior of the reactor to sample the solution around the sediment sample inside the reactor.

[0013] In a second aspect, a carbon dioxide hydration mineralization storage method is provided, which uses the carbon dioxide hydration mineralization storage device described in the first aspect to carry out a carbon dioxide hydration mineralization storage test.

[0014] Further, the following steps are included: (1) Clean and dry the reactor, and place the sediment sample in the sediment sample placement unit; (2) injecting an aqueous solution containing Ca into the reactor through the gas-liquid injection unit. 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, 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 hydrate and mineralizes with the sediment sample; (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.

[0015] Furthermore, the method further comprises at least one of the following: The amount of carbon dioxide stored is calculated by monitoring the temperature and pressure changes; 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; The Raman peaks measured are 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; The sediment samples after the reaction were tested by weight and XRD.

[0016] Furthermore, the sediment sample in step (1) contains feldspar minerals; In step (4), a small amount of liquid carbon dioxide is first continuously injected. When a hydrate cap layer is observed to be formed above the sediment sample from the visual observation window, a large amount of liquid carbon dioxide is continuously injected to achieve mineralization and storage of carbon dioxide by utilizing the mineral dissolution and ion release in the sediment sample combined with the bicarbonate ions generated by the dissolution of carbon dioxide, thereby forming a double storage of hydrate cap layer plus carbon dioxide mineralization.

[0017] The present invention has the following advantages: 1. The carbon dioxide hydration mineralization storage device and method of the present invention can simulate the hydration mineralization of carbon dioxide and store it by injecting carbon dioxide into a medium rich in alkaline metal ions (such as , ) in a geological environment with high carbon dioxide content, the synergistic effect of carbon dioxide hydrate formation and carbon dioxide mineralization can be used to greatly increase the storage capacity and long-term stability of carbon dioxide, providing a new means for offshore carbon dioxide storage.

[0018] 2. The temperature control and monitoring unit and the pressure control and monitoring unit can ensure that the temperature and pressure inside the reactor are constant, simulating the temperature and pressure environment of the actual seabed sediment layer, and can monitor the carbon dioxide hydration mineralization process in the reactor.

[0019] 3. In the preferred solution, the dynamic change of ion concentration with reaction time can be monitored by the in-situ sampling unit, so that the change of chemical properties of the aqueous solution during the reaction can be clearly identified and the reaction termination time can be determined.

[0020] 4. In the preferred embodiment, the solubility of carbon dioxide can be monitored in situ by Raman probe, thereby quantifying the dissolved amount and diffusion coefficient of carbon dioxide and observing the formation and structural evolution of carbon dioxide hydrates and carbonate minerals in real time.

[0021] 5. Through the visual observation window, the hydrate formation inside the reactor and the dissolution of the sediment samples can be observed in real time. The liquid level inside the system after each in-situ sampling can be observed to clarify the time that the sediment samples at different heights are immersed in the solution, providing a basis for the selection of points for subsequent mineral testing.

[0022] 6. Break through the limitation of traditional carbon dioxide hydrate storage that only focuses on phase equilibrium zones and sediment properties, and further propose a site selection strategy based on mineral composition, preferably selecting sediment samples containing feldspar minerals for hydrated mineralization storage, to further increase the storage capacity. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is a schematic structural diagram of a carbon dioxide hydration mineralization storage device in Example 1 of the present invention; Figure 2 is a schematic cross-sectional view of the reactor in Example 1 of the present invention; Figure 3 is a flow chart of the carbon dioxide storage test in Example 2 of the present invention and Comparative Example 1; Figure 4 is the morphological evolution during the hydration mineralization process in Example 2 of the present invention; Figure 5 is the difference in surface porosity of the sediment sample before and after the reaction in Example 2 of the present invention; Figure 6 are SEM results of four parts of the sediment sample after the reaction in Example 2 of the present invention; Figure 7 It is a schematic diagram comparing the carbon dioxide storage amount in Example 2 of the present invention and Comparative Example 1. DETAILED DESCRIPTION

[0024] The following is a detailed description of the embodiments of the present invention. It should be emphasized that the following description is only exemplary and is not intended to limit the scope and application of the present invention. In the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other.

[0025] The inventors found in their research that when carbon dioxide is injected into the marine sediment layer, it will not only form hydrates, but also react with the minerals in the seabed sediment layer, and will be fixed in the strata for a long time in the form of carbonate minerals, achieving the synergistic storage effect of carbon dioxide hydrates and carbon dioxide mineralization. This process is called hydrate-based carbon mineralization. Hydration mineralization combines the carbon dioxide storage of carbon dioxide hydrate formation and carbon dioxide water mineralization. Its core principle is to inject carbon dioxide into alkaline metal minerals and alkaline metal ions (such as , ) in the geological environment of formation water, the synergistic effect of hydrate formation and mineralization reaction is used to achieve long-term stable storage of carbon dioxide. Through the new method of carbon dioxide storage, hydrate mineralization, the problem that a large amount of gas phase, liquid phase and dissolved phase carbon dioxide in hydrate carbon dioxide storage has not been converted into a stable hydrate phase can be solved, and the large amount of alkali metal minerals in the formation can be fully utilized to convert carbon dioxide into long-term stable carbonate minerals. The formation of hydrate lattices significantly increases the ion concentration of fluids in pores, and the formation water rich in alkaline ions provides a favorable chemical environment for the occurrence of mineralization, achieving the synergistic effect of carbon dioxide mineralization storage and hydrate storage, and improving the storage capacity and storage efficiency of carbon dioxide. In addition, hydrate mineralization storage has a high mineral conversion rate and high storage stability. In the sediment layer rich in alkaline minerals in the ocean, the carbon dioxide mineralization conversion rate can reach more than 55%, the carbon dioxide hydrate phase stability period is >1000 years, and the mineral phase is >10000 years. This collaborative storage model provides a solution that combines engineering feasibility and storage efficiency to address climate change, and provides a new path for offshore carbon dioxide storage.

[0026] To this end, the present invention proposes a method and a device that can be used for carbon dioxide hydration mineralization storage experiments, providing theoretical and technical support for the practical application of hydration mineralization technology.

[0027] A specific embodiment of the present invention provides a carbon dioxide hydration mineralization storage device, including 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, and a data acquisition and recording unit; 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 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 monitored by them.

[0028] In some embodiments, the reaction kettle comprises a kettle body and a kettle cover, wherein the kettle cover is sealed to the kettle body; and the visual observation window is arranged on the side of the kettle body.

[0029] In some embodiments, the pressure control and monitoring unit includes a booster 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 booster 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.

[0030] In some embodiments, 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.

[0031] In some embodiments, the sediment sample placement unit includes a placement table and a clamp, the placement table is arranged inside the reactor, the clamp is a barrel-shaped clamp with an open top, the clamp is placed on the placement table, and a plurality of holes are arranged on the circumference of the clamp.

[0032] In some embodiments, the carbon dioxide hydration mineralization storage device also includes a Raman probe and an in-situ sampling unit; the Raman probe extends into the interior of the reactor to monitor the evolution of the reaction process in the reactor in real time and in situ, 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 reactor and connected to the interior of the reactor to sample the solution around the sediment sample inside the reactor.

[0033] The specific embodiment of the present invention also provides a carbon dioxide hydration mineralization storage method, which uses the carbon dioxide hydration mineralization storage device as described above to carry out a carbon dioxide hydration mineralization storage test.

[0034] In some embodiments, the carbon dioxide hydration mineralization storage method comprises the following steps: (1) Clean and dry the reactor, and place the sediment sample in the sediment sample placement unit; (2) injecting an aqueous solution containing Ca into the reactor through the gas-liquid injection unit. 2+ ,Mg 2 + ion; (3) nitrogen is introduced into the reactor through the gas-liquid injection unit to expel the air in the reactor, and the pressure and temperature in the reactor are controlled to reach a first predetermined value, and the reactor is left to stand 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; in this step (3), the sediment sample and the aqueous solution are allowed to stand to balance, so that the storage amount calculated after the subsequent injection of liquid carbon dioxide is the actual carbon dioxide storage amount.

[0035] (4) injecting liquid carbon dioxide into the reactor through the gas-liquid injection unit to exhaust the nitrogen in the reactor, 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 hydrate and mineralizes with the sediment sample; (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.

[0036] In some embodiments, the method further comprises at least one of the following: The amount of carbon dioxide stored is calculated by monitoring the temperature and pressure changes; 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; The Raman peaks measured are 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; The sediment samples after the reaction were tested by weight and XRD.

[0037] In some embodiments, the sediment sample in step (1) contains feldspar minerals, including but not limited to plagioclase.

[0038] In some embodiments, in step (4), a small amount of liquid carbon dioxide is first continuously injected (first stage). When a hydrate cap layer is observed to be formed above the sediment sample from the visual observation window, a large amount of liquid carbon dioxide is continuously injected (second stage) (i.e., the amount of liquid carbon dioxide continuously injected in the second stage is greater than the amount of liquid carbon dioxide continuously injected in the first stage). The mineralization and storage of carbon dioxide is achieved by combining the mineral dissolution and ion release in the sediment sample with the bicarbonate ions generated by the dissolution of carbon dioxide, thereby forming a double storage of hydrate cap layer and carbon dioxide mineralization. Among them, in the early stage of continuous injection of a small amount of liquid carbon dioxide, the main occurrences were the formation of carbon dioxide hydrates and mineral dissolution and ion release of sediment samples. During the formation of carbon dioxide hydrates, the hydrates climbed upward to form a dense hydrate cap layer above the sediment samples, inhibiting the upward migration of carbon dioxide. After the formation of the hydrate cap layer was observed, liquid carbon dioxide was continuously injected in large quantities, mainly utilizing the mineral dissolution and ion release in the sediment samples combined with the bicarbonate ions generated by the dissolution of carbon dioxide to achieve the mineralization and storage of carbon dioxide, thereby forming a coordinated storage of the upper hydrate cap layer and the lower mineralized layer, greatly improving the storage capacity and efficiency of carbon dioxide.

[0039] The present invention is further described below through specific examples. Example 1

[0040] like Figure 1 and 2As shown, the carbon dioxide hydration mineralization storage device in this example can perform real-time analysis of the ion concentration in the carbon dioxide hydration 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 reactor, a gas-liquid injection unit, a temperature control and monitoring unit, a pressure control and monitoring unit, a visual 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 reactor can simulate the low-temperature and high-pressure environment of the carbon dioxide hydration mineralization reaction using seabed sediments, and can withstand the corrosion of carbon dioxide, and includes a reactor body 5 and a reactor cover 18, and the reactor cover 18 is sealed with the reactor body 5, for example, the reactor cover 18 can be rotated to the bottom by a thread and sealed with a gasket and the reactor body. The visual observation window 17 and the in-situ sampling unit 13 are both arranged on the side of the kettle body 5. The visual observation window 17 can be sealed by screws and washers. The morphology of hydrate generation and the mineralization process during the hydration mineralization process can be observed through the visual observation window 17 to clarify the spatial distribution of carbon dioxide hydrate formation and mineralization during the hydration mineralization process; the in-situ sampling unit 13 is used to sample the solution around the sediment sample inside the reactor. The sampled ion concentration can be tested by ICP and pH meters to clarify the impact of hydration mineralization on the chemical environment of the formation water.

[0041] The Raman probe 9 is arranged on the kettle cover 18 and extends into the kettle body 5 to monitor the evolution of the reaction process in the reactor in real time, such as monitoring the dissolution of carbon dioxide and the formation of hydrates, and observing the formation and structural evolution of carbon dioxide hydrates and carbonate minerals in real time.

[0042] The pressure control and monitoring unit is configured to control and monitor the pressure during the reaction process of the reactor to ensure that the reaction pressure is at the actual formation pressure, and includes a booster device 3 and a pressure sensor 7; the gas-liquid injection unit is connected to the reactor and is used to inject gas-liquid samples into the reactor, and includes 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, wherein the gas inlet and outlet 21 is arranged above the reactor cover 18, and the liquid inlet and outlet 19 is arranged at the bottom of the reactor body 5; the carbon dioxide gas cylinder 1 and the nitrogen gas cylinder 2 are connected to the interior of the reactor body 5 through the booster 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 reactor body 5 and extends into the interior of the reactor body 5, and the pressure sensor 7 is connected to the data acquisition and recording unit.

[0043] The temperature control and monitoring unit is configured to control and monitor the temperature of the reactor during the reaction process, 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. The temperature sensor 8 is arranged on the reactor cover 18 and extends into the interior of the reactor body 5. The constant temperature water bath 10 is connected to the water tank 11 to adjust the water bath temperature of the reactor to restore the real temperature environment of the seabed.

[0044] The sediment sample placement unit is located in the reactor and is used to clamp the sediment sample. It includes a placement table 12 and a clamp 14. The placement table 12 is located on the bottom surface of the reactor body 5. The clamp 14 is a barrel-shaped clamp with an open top. The clamp 14 is placed on the placement table 12. A plurality of holes are arranged on the circumference of the clamp 14. During the experiment, the actual sediment sample of the seabed (also referred to as the sediment sample in this article) is placed in the clamp 14. The clamp 14 allows Ca in the solution to 2+ ,Mg 2+ Ions are exchanged between the sediment sample and the solution outside the holder 14. In this example, small holes with a diameter of 1 mm are distributed around the circumference of the holder 14 (not shown).

[0045] 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 via the data transmission device 20 and recorded by the computer 16 .

[0046] The following describes the carbon dioxide storage experiment. Figure 3 This is a flow chart of the carbon dioxide storage method, which mainly includes the following steps: 1. Target area selection and sample selection; 2. Pre-experimental testing of reaction samples; 3. Conducting two groups of experiments on carbon dioxide hydrate storage and carbon dioxide hydration mineralization respectively, and comparing the effects of hydration mineralization on promoting carbon dioxide storage; 4. Testing the samples after the experiment, including the weight of the samples after the reaction, the mineral microstructure, the ion concentration composition of the solution after the reaction, and the mineral composition of the samples after the reaction. Example 2 (Hydration Mineralization Test)

[0047] The carbon dioxide hydration mineralization storage method in this example is carried out using the carbon dioxide hydration mineralization storage device of Example 1. Figure 3 As shown, the following steps are included: (1) The sediment sample is tested before reaction to determine its weight, mineral composition and other parameters. Then the reactor is cleaned and blown dry, and the sediment sample is placed in a holder 14 on a storage table 12 in the reactor; In this case, the W17 well in the Shenhu area of ​​the Baiyun Sag in the Pearl River Mouth Basin of the South China Sea was taken as the actual target area, and the carbon dioxide hydration mineralization test was carried out using actual sediment core rocks (sediment samples).

[0048] The properties of the sediment samples in this case: The whole-rock XRD analysis test of the sediment samples determined 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%, dolomite 1.8%. Quartz is the main brittle mineral, and its rigid skeleton effect is conducive to the development and preservation of the pore system. The composition analysis of clay minerals shows (volume fraction of the total amount of clay minerals): illite-montmorillonite mixed layer (I / S) 50% (montmorillonite layer accounts for 54%), illite 27%, kaolinite 11%, and chlorite 12%.

[0049] (2) A water solution having the same composition as the actual sediment formation water is injected into the reactor through the liquid inlet and outlet 19, wherein Ca 2+ The concentration is 1382.4 mg / L, Mg 2+ The ion concentration is 112.1 mg / L, Na + The ion concentration is 344.9 mg / L, Cl - The ion concentration is 3300.4 mg / L; (3) nitrogen is introduced into the reactor through the nitrogen gas cylinder 2 and the booster 3 to remove the air in the reactor and increase the pressure, the reactor is placed in the water tank 11, and the desired test temperature is set on the constant temperature water bath 10. When the pressure and temperature in the reactor reach the first predetermined value (wherein the pressure is 6 MPa and the temperature is 15° C.), the reactor is left to stand for 24 hours 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) Liquid carbon dioxide is injected into the reactor through the carbon dioxide gas cylinder 1, the booster 3, the gas inlet and outlet valve 6, and the gas inlet and outlet 21 to exhaust the nitrogen in the reactor and increase the pressure until the test pressure is reached, and the test temperature is set through the constant temperature water bath 10, and the temperature is lowered 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 generates hydrates and mineralizes with the sediment sample; wherein, in this step, a small amount of liquid carbon dioxide is continuously injected first, and when a hydrate cap layer is observed to be formed above the sediment sample from the visual observation window, a large amount of liquid carbon dioxide is continuously injected, and the mineralization and storage of carbon dioxide is realized by utilizing the mineral dissolution and alkaline ion release in the sediment sample combined with the bicarbonate ions generated by the dissolution of carbon dioxide, thereby forming a double storage of hydrate cap layer and carbon dioxide mineralization.

[0050] like Figure 4 As shown in Figure 2, the morphological evolution of hydrate mineralization process is shown in Figure 2, where t n It indicates the time when hydrate nucleation begins. After the injection of liquid carbon dioxide, the temperature drops, resulting in the phenomenon of carbon dioxide hydrate climbing the wall and growing (forming a hydrate cap layer above the sediment sample). The sediment sample is at the bottom of the reactor. The formation of hydrate consumes water, increasing the concentration of alkaline ions in the solution and further accelerating the mineralization reaction.

[0051] (5) In the hydration mineralization reaction of step (4), the solution around the sediment sample is sampled by the in-situ sampling unit 13 at predetermined intervals, and Ca 2+ ,Mg 2+ Ion concentration detection; transmitting the measured Raman peak to the data acquisition and recording unit through the Raman probe to monitor the evolution of the reaction process in the reactor in real time (specifically, monitoring the dissolution of carbon dioxide and the generation of hydrates, and observing the formation and structural evolution of carbon dioxide hydrates and carbonate minerals in real time); monitoring the temperature and pressure in the reactor in real time through the temperature control and monitoring unit and the pressure control and monitoring unit and transmitting them 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 ended. The amount of carbon dioxide stored is calculated by monitoring the temperature and pressure changes, and the mineral ratio of carbon dioxide mineralization is obtained by weight and XRD testing of the sediment sample after the reaction.

[0052] In this example, if Figure 5 and 6 As shown in the figure, after the reaction, obvious carbonate minerals were observed under the microscope, characterized by calcite minerals in the energy spectrum. At the same time, obvious dissolution pores were generated on the surface of the sediment sample. The porosity of the sample surface increased with the increase of reaction time, providing pore space for hydrate growth. This is caused by mineral dissolution in an acidic environment (such as Figure 5 As shown in the figure, 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%). XRD results show that the content of plagioclase decreased from 4.3% to 0%, while calcite and dolomite increased slightly, 22.5% and 3.2% respectively, which indicates that the dissolution of feldspar minerals provides an ionic environment for the formation of carbonate minerals in the solution, and the HCO3 produced by the dissolution of CO2 - Ions and Ca 2+ ,Mg 2+ The action of ions produces calcite and dolomite.

[0053] In this example, the storage capacity is calculated by referring to the method in Chinese patent application CN 116148303 A, wherein the density of the aqueous solution of the present invention is approximately equal to the density of pure water, and the storage capacity of hydrated mineralized carbon dioxide reaches 55.11 (the volume of carbon dioxide stored per unit system under standard conditions, i.e., the storage volume of carbon dioxide V CO2 The volume of the aqueous solution V 水 The ratio is 55.11). Comparative Example 1 (Hydrate Formation Test)

[0054] like Figure 3 As 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, and the particle size and porosity of the quartz sand before the test are consistent with those of the sediment sample. The other test processes are the same as those of Example 2, and in this Comparative Example 1, there is no hydrate mineralization process. Similarly, the calculation of the storage capacity of Comparative Example 1 refers to the method in Chinese patent application CN 116148303 A.

[0055] The carbon dioxide storage volume (V) of the hydrated mineralization storage in Example 2 and the hydrate storage in Comparative Example 1 CO2 The volume of the aqueous solution V 水 The ratio of is expressed as Figure 7 As shown, by comparing Example 2 with Comparative Example 1, it can be seen that the hydration mineralization of Example 2 can greatly promote the effect of carbon dioxide storage and increase the storage capacity. It can be seen from the calculation results of the gas consumption that compared with the storage of carbon dioxide hydrates alone, the carbon dioxide storage capacity of hydrated mineralization is increased by about 18%.

[0056] It can be seen from the above embodiments that the carbon dioxide hydrate mineralization storage method and device of the present invention aims to achieve efficient and stable storage of carbon dioxide by combining the two mechanisms of carbon dioxide hydrate formation and carbon dioxide mineralization, and its advantages include: 1. Hydration and mineralization synergistic storage: The reactor of the present invention is a multiphase reactor 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 hydrate rich in alkaline metal ions (such as , ) in a geological environment with low carbon dioxide content, the synergistic effect of hydrate formation and mineralization reaction is utilized to significantly increase the storage capacity and long-term stability of carbon dioxide, and improve the storage efficiency of carbon dioxide.

[0057] 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. Combined with in-situ Raman spectroscopy technology, it can quantify the dissolution of carbon dioxide and the formation of hydrates, and observe the formation and structural evolution of hydrates and carbonate minerals in real time.

[0058] 3. Accurately simulate the actual geological environment: Through a constant temperature water bath and a gas pressurization device, the low temperature and high pressure environment of the seabed sediment layer is simulated to ensure that the experimental conditions are consistent with the actual geological conditions and obtain reliable and accurate experimental results.

[0059] 4. In-situ sampling and mineralogical analysis: The dynamic changes of ion concentration over time are monitored through the in-situ sampling unit, and combined with the mineralogical analysis after the reaction, the main controlling factors and mineralization mechanism of carbon dioxide hydration mineralization are deeply explored.

[0060] 5. Multi-scale simulation: The above-mentioned automatic control unit introduced in the device and method of the present invention realizes the automatic operation and data recording of the experimental process, reduces human errors, and realizes multi-scale simulation from micro to macro by monitoring the dynamic changes in the reaction process, combining numerical simulation with experimental research, and comprehensively reveals the reaction mechanism of carbon dioxide hydration mineralization.

[0061] 6. Break through the limitation of traditional carbon dioxide hydrate storage that only focuses on phase equilibrium zones and sediment properties, and further propose a site selection strategy based on mineral composition, preferably selecting sediment samples containing feldspar minerals for hydrated mineralization storage, to further increase the storage capacity.

[0062] The device and method of the present invention can be applied to the following fields: 1. Deep-sea carbon dioxide storage: Achieve long-term and stable storage of carbon dioxide in deep-sea sediments.

[0063] 2. Storage of abandoned offshore oil and gas fields: Utilize the geological conditions of abandoned oil and gas fields to achieve efficient storage of carbon dioxide.

[0064] 3. Direct storage of ship flue gas: Through the carbon capture facilities on the ship, carbon dioxide is collected and stored through hydration mineralization.

[0065] 4. Industrial waste gas treatment: used to capture and store carbon dioxide in industrial waste gas to reduce carbon emissions.

[0066] 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 limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, without departing from the concept of the present invention, it can also make several substitutions or modifications to these described embodiments, and these substitutions or modifications should be regarded as belonging to the protection scope of the present invention. In the description of this specification, the description of the reference terms "an embodiment", "some embodiments", "preferred embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in combination 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 target 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. In the absence of mutual 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 modifications can be made herein without departing from the scope of protection of the patent application.

Claims

1. A carbon dioxide hydration mineralization storage device, characterized in that: It includes 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, and a data acquisition and recording unit; 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 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.

2. The carbon dioxide hydration mineralization storage device 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.

3. The carbon dioxide hydration mineralization storage device according to claim 2, 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.

4. The carbon dioxide hydration mineralization storage device according to claim 2, 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.

5. The carbon dioxide hydration mineralization storage device 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.

6. The carbon dioxide hydration mineralization storage device according to claim 1, characterized in that: The carbon dioxide hydration mineralization storage device also includes a Raman probe and an in-situ sampling unit; the Raman probe extends into the interior of the reactor to monitor the evolution of the reaction process in the reactor in real time and in situ, 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 reactor and connected to the interior of the reactor to sample the solution around the sediment sample inside the reactor.

7. A method for storing carbon dioxide by hydration mineralization, characterized in that: A carbon dioxide hydration mineralization storage test is carried out using the carbon dioxide hydration mineralization storage device as described in any one of claims 1 to 6.

8. The method for storing carbon dioxide by hydration mineralization according to claim 7, characterized in that: The steps include: (1) Clean and dry the reactor, and place the sediment sample in the sediment sample placement unit; (2) injecting an aqueous solution containing Ca into the reactor through the gas-liquid injection unit. 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, 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 hydrate and mineralizes with the sediment sample; (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.

9. The method for storing carbon dioxide by hydration mineralization according to claim 8, characterized in that: The method further comprises at least one of: The amount of carbon dioxide stored is calculated by monitoring the temperature and pressure changes; The solution around the sediment sample is sampled by the in-situ sampling unit at predetermined intervals, and Ca 2+ ,Mg 2+ Ion concentration detection; The Raman peaks measured are 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; The sediment samples after the reaction were tested by weight and XRD.

10. The method for storing carbon dioxide by hydration mineralization according to claim 8, characterized in that: The sediment sample in step (1) contains feldspar minerals; In step (4), a small amount of liquid carbon dioxide is first continuously injected. When a hydrate cap layer is observed to be formed above the sediment sample from the visual observation window, a large amount of liquid carbon dioxide is continuously injected to achieve mineralization and storage of carbon dioxide by utilizing the mineral dissolution and ion release in the sediment sample combined with the bicarbonate ions generated by the dissolution of carbon dioxide, thereby forming a double storage of hydrate cap layer plus carbon dioxide mineralization.

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