Controllable nucleation method for CO2 hydrate

Abstract

The invention discloses a CO2 hydrate controllable nucleation method. The method comprises the following steps: preparing a water-soluble packaging material; coating active metal with the water-soluble packaging material and carrying out sealed packaging to obtain an active metal water-soluble packaging body; the active metal water-soluble packaging body is used for inducing generation of CO2 hydrate in the CO2 sealing process. In the process of manufacturing the water-soluble packaging material, the dissolution rate of the water-soluble packaging material in water is controlled by regulating and controlling at least one of the material components, the component proportion and the material thickness, so that the nucleation induction time when the active metal water-soluble packaging body is used for inducing generation of CO2 hydrate is controlled.

Description

Technical Field

[0001] The present invention relates to the technical field of carbon sequestration, and particularly relates to a method for controllable nucleation of CO2 hydrate. Background Art

[0002] With the acceleration of the industrialization process, the world is facing increasingly severe greenhouse gas emission problems, especially the excessive emission of carbon dioxide (CO2). To mitigate global warming, it is particularly important to develop effective CO2 capture and sequestration technologies. As a potential solution, the core idea of CO2 sequestration by hydrate method is to sequester CO2 in the form of solid hydrate in submarine sediments, and utilize the low temperature and high pressure environment of the seabed to achieve long-term and stable sequestration of CO2.

[0003] In the CO2 sequestration technology by hydrate method, regulating the nucleation and growth kinetics of CO2 hydrate is one of the key technologies. Traditional hydrate formation methods rely on a stirring system, which has problems such as slow reaction rate, strong randomness of induction time, and high energy consumption; in addition, the operation of the stirring system is complex and it is difficult to achieve large-scale application in the marine environment. Therefore, developing a technology that can regulate the nucleation and growth of CO2 hydrate in a static system is of great significance for improving CO2 sequestration efficiency and reducing costs.

[0004] In the marine environment, active metals represented by magnesium (Mg), if directly in contact with CO2 hydrate, can effectively induce nucleation, but the induction time is extremely short and the nucleation process is difficult to control, which cannot meet the requirement of achieving CO2 hydrate nucleation in a specified area on the seabed. In addition, active metals are extremely vulnerable to corrosion by physical, chemical, and biological factors in the marine environment, which not only limits their application in CO2 hydrate formation, but may also cause pollution to the marine environment. Traditional encapsulation materials often have difficulty in balancing anti-corrosion performance and the nucleation promotion effect of active metals. Summary of the Invention

[0005] In view of this, the present invention encapsulates active metals with self-designed and synthesized water-soluble materials to effectively protect the active metals while retaining their nucleation ability, and then proposes a method for controllable nucleation of CO2 hydrate based on water-soluble material-encapsulated active metals. This method realizes the controllable triggering of CO2 hydrate nucleation by the active metals through the controllable dissolution rate of the water-soluble materials, and effectively prevents the active metals from being corroded during transportation to improve the use value of the active metals in promoting CO2 hydrate formation, and finally solves the problems existing in the above-mentioned prior art.

[0006] To solve the problems existing in the prior art, the present invention adopts the following technical solutions:

[0007] A method for controllable nucleation of CO2 hydrate, comprising: fabricating a water-soluble encapsulating material; coating an active metal with the water-soluble encapsulating material and performing hermetic encapsulation to obtain an active metal water-soluble encapsulant; and using the active metal water-soluble encapsulant in the process of CO2 sequestration to induce the formation of CO2 hydrate.

[0008] Further, the method for controllable nucleation of CO2 hydrate further comprises: in the process of fabricating the water-soluble encapsulating material, controlling the dissolution rate of the water-soluble encapsulating material in water by regulating at least one of the material components, component ratios, and material thicknesses, so as to control the nucleation induction time when the active metal water-soluble encapsulant is used to induce the formation of CO2 hydrate.

[0009] Further, the water-soluble encapsulating material is a starch-based water-soluble material, and the fabrication steps include:

[0010] S1. Mix bone glue and polyvinyl alcohol to obtain a mixture, mix 5-100 wt% of the mixture with 0-95 wt% of starch and dissolve it in water to prepare a starch-based water-soluble material solution with a concentration of 150-400 g / L, stir evenly and remove bubbles;

[0011] S2. Pour the solution prepared in step S1 into a predetermined mold and heat to cure and shape the starch-based water-soluble material, and then demold to obtain the water-soluble encapsulating material with a predetermined shape.

[0012] Further, the water-soluble encapsulating material is fabricated into a film shape or a capsule shape.

[0013] Further, it further comprises: cutting the active metal into a shape and size adapted to the water-soluble encapsulating material, then coating the cut active metal with the water-soluble encapsulating material, and heating the water-soluble encapsulating material to achieve thermoforming sealing.

[0014] Further, the temperature for heating and curing and shaping in step S2 is 60-80 °C.

[0015] Further, the heating temperature for achieving the thermoforming sealing is 80-100 °C.

[0016] Further, the active metal includes one or a mixture of two or more of magnesium, aluminum, and zinc.

[0017] The beneficial effects of the technical solution of the present invention are reflected in that the present invention seals active metals in an environmentally friendly water-soluble encapsulating material for CO2 subsea storage, and constructs a "liquid-solid-liquid-solid-gas" (solution outside the water-soluble encapsulating material - water-soluble encapsulating material - solution entering the inside of the encapsulating material after the water-soluble encapsulating material dissolves - active metal inside the water-soluble encapsulating material - H2 bubbles generated on the surface of the active metal) contact mode. On the one hand, it reduces the degree of oxidation of the active metal before the induction nucleation, prevents the active metal from being corroded in advance, and improves the conversion rate of gases such as CO2 to the hydrate phase. On the other hand, the dissolution rate of the material can be regulated by adjusting the components / component ratio / material thickness of the water-soluble encapsulating material, so as to control the nucleation induction time of the active metal water-soluble encapsulation body for inducing the formation of CO2 hydrate, achieving controllable nucleation. Thus, the problems that the prior art cannot achieve the controllable and timed generation of CO2 hydrate and the active metal is rapidly corroded during the subsea transportation process are solved.

[0018] The present invention can produce water-soluble encapsulating materials with different dissolution rates as required to make the dissolution time controllable. The technical effects are also reflected in the following aspects:

[0019] 1) Controlling the nucleation induction time of hydrates

[0020] Traditional hydrate formation methods rely on a stirring system, with a slow reaction rate and a long induction time required for hydrate nucleation. Active metals represented by magnesium can effectively promote the nucleation of CO2 hydrates. In pure water, the induction time required for hydrate nucleation is shortened to within 10 s, which is much lower than the time required for active metals to be transported to the designated nucleation location in the ocean, and is not conducive to the controllable formation of hydrates within a certain depth range in the ocean. However, the water-soluble material encapsulating the active metal can extend the nucleation induction time to the specified time, realizing the controllable induced nucleation of CO2 within the specified ocean depth range, making the CO2 hydrate storage technology more practical and economical.

[0021] Through controllable technical means, the nucleation time of CO2 hydrates can be accurately controlled at a specific time point, avoiding the low storage efficiency caused by the randomness of the nucleation time. For example, in traditional methods, the nucleation induction time may fluctuate greatly due to slight changes in environmental conditions, while the controllable technology of the present invention can ensure stable nucleation within a predetermined time, thereby improving the storage efficiency of CO2.

[0022] In the marine environment, accurately controlling the nucleation position can ensure the formation of CO2 hydrates in specific areas on the seabed, avoiding poor storage effects caused by the uncertainty of the nucleation position. Through controllable technology, efficient formation of CO2 hydrates can be achieved in designated areas on the seabed, improving the stability and safety of storage.

[0023] 2) Effectively promote the growth kinetics of hydrates

[0024] The present invention constructs a "liquid-solid-liquid-solid-gas" (solution outside the water-soluble encapsulating material - water-soluble encapsulating material - solution that enters the interior of the encapsulating material after the water-soluble encapsulating material dissolves - active metal inside the water-soluble encapsulating material - H2 bubbles generated on the surface of the active metal) contact mode, combines the active metal with an environmentally friendly water-soluble material, and optimizes and regulates the formation of hydrates through the multiphase interface. This unique system construction method can control the nucleation time of hydrates regularly, and improve the formation rate and conversion rate of hydrates.

[0025] 3) Enhance the corrosion resistance and service life of active metals

[0026] In the marine environment, active metals are vulnerable to corrosion by physical, chemical, and biological factors, which limits their application in promoting the formation of CO2 hydrates. The present invention encapsulates the active metal with a water-soluble material, which has good water resistance and mechanical properties, can effectively protect the active metal during transportation and use, and prevent it from being corroded by seawater. It extends the service life of the active metal, ensures its long-term stable role in promoting the formation of CO2 hydrates, and improves the reliability and economy of the sequestration technology.

[0027] 4) Reduce energy consumption and costs

[0028] Traditional hydrate formation stirring systems have high energy consumption, while the present invention realizes the rapid formation of CO2 hydrates in a static system without stirring, without complex stirring equipment and operations, saving the energy consumption generated by mechanical stirring. For example, by controlling the nucleation and growth process of hydrates, energy losses caused by stirring can be avoided, and the energy utilization efficiency of the entire sequestration process can be improved.

[0029] The controllable nucleation technology can reduce the dependence on complex equipment and expensive materials. For example, by precisely controlling the nucleation process, material waste caused by too long or too short nucleation time can be avoided, and the material cost of the sequestration process can be reduced.

[0030] At the same time, the use of toxic chemical reagents is reduced, the reagent cost and the environmental pollution risk are lowered, making the CO2 sequestration process more economical and environmentally friendly, and facilitating the large-scale application and promotion of the hydrate method for CO2 sequestration technology.

[0031] 5) Enhance the safety of sequestration

[0032] In the marine environment, an uncontrollable nucleation process may lead to uncertainties in the generation location and time of CO2 hydrates, thereby increasing the safety risks of sequestration. Through controllable technologies, it is possible to ensure the generation of CO2 hydrates under predetermined conditions and avoid sequestration failure caused by uncontrollable factors. The controllable nucleation technology can ensure the stable generation of CO2 hydrates on the seabed and reduce the instability of the sequestration structure caused by the randomness of the nucleation process.

[0033] 6) Adapt to complex environments

[0034] The marine environment is complex and variable, and traditional nucleation methods are difficult to adapt to such changes. The controllable nucleation technology can adapt to different marine environment changes by flexibly adjusting the nucleation conditions, thereby improving the adaptability and reliability of the sequestration technology.

[0035] Achieving large-scale CO2 sequestration in the marine environment requires highly controllable technical means. Through the controllable nucleation technology, efficient CO2 sequestration can be achieved in different marine regions and conditions, providing technical support for large-scale applications. Description of the Drawings

[0036] Figure 1 is a flowchart of the method for controllable nucleation of CO2 hydrates encapsulating active metals based on water-soluble materials according to an embodiment of the present invention.

[0037] Figure 2 is a schematic diagram of the experimental process for the generation of CO2 hydrates according to an embodiment of the present invention.

[0038] Figure 3 is the change in the morphology of the substances in the reaction kettle during the experimental process of the generation of CO2 hydrates in a pure water system according to an embodiment of the present invention.

[0039] Figure 4 is the induction time of the embodiment of the present invention and the comparative example. Detailed Embodiments

[0040] The present invention will be further described below in conjunction with the drawings, specific embodiments, and examples. The purpose of providing the examples is only for illustration and not for any limitation.

[0041] An embodiment of the present invention provides a method for controllable nucleation of CO2 hydrates encapsulating active metals based on water-soluble materials. Please refer to Figure 1 , and the method includes:

[0042] Prepare a solution of a starch-based water-soluble encapsulating material: Mix 0-95 wt% of starch with 5-100 wt% of a gelatin / polyvinyl alcohol mixture and dissolve it in water to prepare a solution with a concentration of 150-400 g / L, stir evenly and remove air bubbles; wherein, the gelatin / polyvinyl alcohol mixture can be composed of gelatin and polyvinyl alcohol in any mass ratio;

[0043] Curing of starch-based water-soluble materials with specific shapes: Pour the above-obtained solution into a customized mold, and then place the mold in an oven at 60-80 °C to cure and shape the starch-based water-soluble materials. Subsequently, demolding is carried out to obtain water-soluble encapsulation materials with specific shapes (such as film-like or capsule-shaped in the embodiments of the present invention);

[0044] Pretreatment of active metals: Cut the active metal (such as magnesium) into a shape and size adapted to the water-soluble encapsulation material;

[0045] Encapsulation of metals with water-soluble materials: Coating the active metal with a water-soluble encapsulation material, and further thermoforming the water-soluble encapsulation material at 80-100 °C to seal the active metal inside;

[0046] Using water-soluble materials to encapsulate metals for regulating hydrate nucleation: Using the active metal encapsulated with water-soluble materials to induce the formation of CO2 hydrates during the CO2 sequestration process.

[0047] It should be understood that the water-soluble materials used to encapsulate active metals are not limited to the above-mentioned starch-based water-soluble materials, but can also be water-soluble inorganic non-metallic materials or biodegradable materials (the water-soluble capsules made of biodegradable materials not only have good water resistance and mechanical properties, but can also be naturally degraded after use, reducing environmental pollution); or intelligent responsive materials: Develop water-soluble capsules that can respond intelligently to specific environmental conditions (such as temperature, pressure, pH value), so that they can dissolve under the best conditions, further improving the controllability of hydrate formation. Mainly consider environmental protection, economy, easy dissolution in water (especially seawater), no reaction with active metals, and no influence on the induction of CO2 hydrates by active metals.

[0048] In some specific embodiments, surface modification or structural optimization can also be carried out on the water-soluble encapsulation materials. Surface modification examples are as follows:

[0049] ① Surface coating: Coating a special coating on the surface of the water-soluble encapsulation material, such as a hydrophobic coating, a hydrophilic coating, etc., to optimize the dissolution performance and protection performance of the water-soluble capsule.

[0050] ② Nano-coating: Using a coating made of nano-materials to improve the corrosion resistance and mechanical strength of the water-soluble capsule and extend the service life of the water-soluble capsule.

[0051] Examples of structural optimization are as follows:

[0052] ① Micro-nano structure: Manufacturing a micro-nano structure on the surface of the water-soluble encapsulation material to change the specific surface area of the water-soluble encapsulation material and the contact area with the active metal, and change the dissolution rate and protection performance of the water-soluble encapsulation material.

[0053] ② Porous structure: A porous structure is fabricated inside the water-soluble encapsulating material to improve the air permeability and water permeability of the water-soluble encapsulating material and optimize the controllable release effect of the metal.

[0054] In addition, it should be understood that the active metal can be, for example, one or a mixture of two or more of magnesium, aluminum, and zinc, or a metal alloy is used. By adjusting the alloy composition, the activity and corrosion resistance of the metal are optimized, and the hydrate formation efficiency and the service life of the metal are improved. In the subsequent embodiments of the present invention, magnesium is taken as an example for illustration.

[0055] The CO2 hydrate controllable nucleation method proposed in the embodiments of the present invention can control the dissolution rate of the water-soluble material in water (especially seawater) by regulating at least one of the material components, component ratios, and material thicknesses when making the water-soluble encapsulating material, so as to control the nucleation induction time when the active metal encapsulated by the water-soluble material is used to induce the formation of CO2 hydrates, and achieve controllable nucleation of CO2 hydrates.

[0056] In some other embodiments, the release of the metal in the water-soluble encapsulating material can be electrochemical release or photochemical release in addition to the aforementioned dissolution release:

[0057] Electrochemical water-soluble encapsulating material: Develop an electrochemical water-soluble encapsulating material to control the dissolution rate of the water-soluble encapsulating material by applying an electric field and achieve precise release of the metal.

[0058] Photosensitive water-soluble encapsulating material: Develop a photosensitive water-soluble encapsulating material to control the dissolution rate of the water-soluble encapsulating material by light irradiation and achieve precise release of the active metal.

[0059] The feasibility and effectiveness of the foregoing technical solutions of the present invention are illustrated below through examples and comparative examples.

[0060] Example: The water-soluble polymer capsule encapsulates magnesium metal to regulate the CO2 hydrate formation kinetics in a pure water experimental system, referring to Figure 2 .

[0061] (1) Prepare 2.5 g of starch-based material (90 wt% starch + 10 wt% gelatin / polyvinyl alcohol mixture), dissolve the prepared starch-based material in 6.0 ml of water, and stir at 40 - 80 °C for 6 h to obtain a solution of the starch-based water-soluble material;

[0062] (2) Pour the ultrasonically treated solution into a No. 0 capsule mold, dry it in an oven at 65 °C for 12 - 16 h, and then take out the solidified water-soluble polymer capsule in the mold;

[0063] (3) Cut the magnesium metal into metal sheets with dimensions of 4.0 mm * 2.0 mm * 0.5 mm;

[0064] (4) Place the cut magnesium metal sheet into a water-soluble capsule, and soften the water-soluble capsule encapsulating the magnesium metal in an oven at 80 °C for 1 h, then place it in a drying dish with a relative humidity of 50% and a temperature of 25 °C for curing and storage to achieve the hermetic encapsulation of the magnesium metal;

[0065] (5) Wash and dry the fully visible reaction kettle, and inject 20 ml of prepared pure water into the reaction kettle; place the magnesium metal sheet encapsulated with the water-soluble capsule into the reaction kettle (not in contact with the seawater solution) and seal it;

[0066] (6) Adjust the temperature of the water bath of the reaction kettle through program temperature control, set the water bath temperature to 275.2 K, after constant temperature for 3 h, inject CO2 gas at 0.5 MPa through the gas injection system to purge the reaction kettle 3 times to remove the air in the reaction kettle;

[0067] (7) Slowly inject CO2 gas to 3.6 MPa, keep the pressure of the reaction system stable, and keep it at a constant temperature in a 275.2 K water bath for 16 h;

[0068] (8) When the pressure change in the reaction kettle is less than 0.01 MPa / h, release the capsule, and the lower end of the capsule is 4.0 mm from the liquid surface. As the water-soluble capsule dissolves, the liquid corrodes the magnesium metal, bubbles are generated on the surface of the magnesium metal, and CO2 hydrate is triggered to form after 45 ± 5 min, as Figure 3 shown. The morphological changes during the formation process of CO2 hydrate are captured in real time by the high-definition CCD camera above the reaction kettle, and the induction time required for hydrate formation is calculated based on the morphological changes. Record the temperature and pressure data during the hydrate formation process;

[0069] (9) When the pressure in the reaction kettle decreases and the reading change is less than 0.01 MPa / h, it indicates that the formation of CO2 hydrate is basically completed. Evaluate the effect of partially encapsulated metal on promoting the formation of CO2 hydrate in this example through the parameters such as the temperature, pressure data recorded in real time, and the time from when the capsule contacts the solution to the formation of hydrate.

[0070] Comparative Example: Kinetics of CO2 Hydrate Formation in a Pure Water Experimental System with Magnesium Metal

[0071] (1) Cut the magnesium metal into metal sheets with dimensions of 4.0 mm * 2.0 mm * 0.5 mm;

[0072] (2) Wash and dry the fully visible reaction kettle, and inject 20 ml of pure water into the reaction kettle; place the magnesium metal sheet into the reaction kettle (not in contact with the pure water) and seal it;

[0073] (3) Adjust the temperature of the water bath of the reactor by programmed temperature control. Set the water bath temperature to 275.2 K. After maintaining the temperature for 3 h, inject CO2 gas at 0.5 MPa through the gas injection system to purge the reactor 3 times to remove the air inside the reactor;

[0074] (4) Slowly inject CO2 gas to 3.6 MPa, keep the pressure of the reaction system stable, and maintain the temperature at 275.2 K in the water bath for 16 h;

[0075] (5) When the pressure change in the reactor is less than 0.01 MPa / h, release the magnesium metal. After the magnesium metal contacts the solution for about 1 s, the formation of CO2 hydrate is triggered. The morphological changes during the formation process of CO2 hydrate are photographed in real time by a high-definition CCD camera above the reactor. The induction time required for hydrate formation is calculated based on the morphological changes, and the temperature and pressure data during the hydrate formation process are recorded;

[0076] (9) When the pressure in the reactor decreases and the reading change is less than 0.01 MPa / h, it indicates that the formation of CO2 hydrate is basically completed.

[0077] The controllable nucleation of CO2 hydrate demonstrated in the above embodiments: After the capsule contacts the solution for 40 ± 5 min, the CO2 hydrate is formed. This induction time is much longer than the nucleation time of the hydrate without being encapsulated by water-soluble materials. The CO2 hydrate has controllable nucleation, and the data is as Figure 4 shown.

[0078] In the above embodiments, a fully visible reactor is used: Through observation with transparent quartz glass and connecting a high-definition CCD camera with adjustable focal length, the nucleation and growth process of hydrates can be clearly observed, providing an intuitive basis for studying the growth kinetics of hydrates. Real-time monitoring: The device is equipped with temperature and pressure sensors, which can measure the temperature and pressure changes during the CO2 hydrate reaction process in real time, helping to deeply understand the mechanism of the kinetic promoter promoting hydrate growth and providing data support for further optimizing the storage technology.

[0079] From the above embodiments, it can be concluded that the method for controllable nucleation of CO2 hydrate based on encapsulating magnesium metal with water-soluble materials proposed by the present invention has the following technical effects:

[0080] (1) Controllable nucleation induction time

[0081] It can control the induction time required for CO2 hydrate nucleation. The induction time of the active metal system represented by magnesium encapsulated with water-soluble materials is generally higher than that of the system without water-soluble material encapsulation, and it is especially suitable for CO2 subsea storage.

[0082] (2) Energy consumption and cost

[0083] Encapsulating active metals with water-soluble materials such as inorganic non-metallic materials that are easily soluble in water or starch-based polymer materials increases the cost of the encapsulating materials, but reduces the corrosion of active metals before the formation of CO2 hydrates and extends the service life of active metals. This solution does not require complex stirring equipment and operations, and the overall energy consumption is lower than that of traditional stirring systems.

[0084] (3) Corrosion resistance

[0085] Encapsulating active metals with capsules made of water-soluble materials such as inorganic non-metallic materials that are easily soluble in water or starch-based polymer materials can provide good corrosion protection and effectively prevent the corrosion of active metals during transportation and use.

[0086] In summary, the inventive points of the present invention are mainly reflected in:

[0087] 1) Regulation of the water solubility of encapsulating materials

[0088] Design and synthesize materials with different water solubilities:

[0089] Design and synthesize materials with adjustable water solubility, such as by adjusting the proportion of different components of the materials to change the solubility, dissolution rate, etc.

[0090] Design and prepare water-soluble capsule shells / membranes with specific thicknesses as needed:

[0091] Encapsulating active metals with water-soluble materials of different thicknesses has different effects on the nucleation induction time (the time from the input of the metal to the start of the formation of hydrates). By adjusting the thickness of the materials, the dissolution time of the materials can be further controlled. For example, the nucleation induction time for encapsulating active metals with pure PVA capsules with a thickness of 0.2 mm is within 10 minutes, while the nucleation induction time for encapsulating active metals with pure PVA capsules with a thickness of 1.0 mm is between 10 and 60 minutes.

[0092] The relationship between water-soluble materials with different components and thicknesses and the nucleation induction time reflects the in-depth exploration of the present invention in optimizing the process of CO2 hydrate formation and needs to be protected.

[0093] 2) Controlled release technology for encapsulating active metals with water-soluble materials:

[0094] According to the difference in the water solubility of the encapsulating material, a water-soluble encapsulating material was independently designed and prepared to enable the timed contact between active metals represented by magnesium metal and seawater solution, thereby achieving the controllable nucleation of CO2 hydrates. For the first time, the dissolution characteristics of water-soluble materials were combined with metal activity, solving the problems of the corrosion of active metals and the uncontrollable nucleation induction time in traditional methods. Water-soluble polymer materials (such as polyvinyl alcohol, starch) or inorganic non-metallic materials that are easily soluble in water were used to make capsules or membranes to encapsulate active metals, and the timed release of active metals was achieved by controlling the dissolution rate of the capsules / membranes. The water-soluble materials protect the magnesium metal from corrosion during transportation. After dissolving in a specific environment (such as seawater), the active metal is exposed to the solution, triggering the nucleation of CO2 hydrates.

[0095] 3) Regulation of hydrate nucleation by a liquid-solid-liquid-solid-gas multiphase cooperative system

[0096] The method of contacting the water-soluble material encapsulating the active metal with the solution (liquid-solid-liquid-solid-gas): The present invention constructs a "liquid-solid-liquid-solid-gas" (solution outside the water-soluble encapsulating material - water-soluble encapsulating material - solution inside the encapsulating material after the water-soluble encapsulating material dissolves - active metal inside the water-soluble encapsulating material - H2 bubbles generated on the surface of the active metal) contact method, combines the active metal with an environmentally friendly water-soluble material, and optimizes the regulation of hydrate formation at the multiphase interface. This unique system construction method can control the nucleation time of hydrates regularly and improve the hydrate formation rate and conversion rate.

[0097] Generally speaking, compared with the existing schemes for CO2 hydrate formation, the highlights of the present invention can be found as follows:

[0098] 1. Controllable release: The dissolution rate of the water-soluble material can be controlled to ensure the release of the metal at appropriate times and conditions;

[0099] 2. Environmentally friendly: Water-soluble materials (such as polyvinyl alcohol, starch, etc.) are harmless to the environment, avoiding the environmental pollution problems that may be brought about by traditional encapsulation technologies;

[0100] 3. Low cost: The water-soluble material encapsulation technology uses low-cost water-soluble materials, significantly reducing the material cost. The present invention can achieve the controllable and timed generation of CO2 hydrates in a static system without the need for complex stirring equipment and operations, saving the energy consumption generated by mechanical stirring;

[0101] 4. Wide applicability: The water-soluble material encapsulation technology is applicable to a variety of metals (such as magnesium, aluminum, etc.) and is not limited by alloying materials;

[0102] 5. Simple process: The water-soluble material encapsulation technology has a simple process and is easy to apply on a large scale.

[0103] The technical solution of the present invention can be applied not only to the controllable nucleation of CO2 hydrate induced in CO2 subsea storage as described above, but also to the following aspects:

[0104] (1) Energy storage

[0105] Natural gas storage: Utilizing the gas storage characteristics of hydrates, the present invention is applied to natural gas storage. Storing natural gas in the form of hydrates can improve the storage density and safety, and reduce the risk of gas leakage.

[0106] Hydrogen storage: As a clean energy source, the storage and transportation of hydrogen are technical challenges. The present invention can be used for the hydrate storage of hydrogen, improving the storage efficiency and safety of hydrogen, and promoting the wide application of hydrogen energy.

[0107] (2) Industrial waste gas treatment

[0108] Capture and storage of CO2 generated in industry: Applying the present invention to industrial waste gas treatment, sealing the CO2 emitted from industry by the hydrate method, reducing greenhouse gas emissions, and realizing the low-carbonization of industrial production.

[0109] Industrial wastewater treatment: Combining industrial wastewater treatment technologies, using the pressure and temperature changes generated during the formation of hydrates to achieve the purification and resource recovery of industrial wastewater.

[0110] (3) Ocean engineering

[0111] Development of subsea mineral resources: During the development of subsea mineral resources, the water-soluble material encapsulation technology of the present invention can be used to protect equipment and tools from seawater corrosion and extend the service life of the equipment.

[0112] Ocean monitoring: Developing sensors and equipment for ocean environmental monitoring, using the water-soluble material encapsulation technology to protect the sensors and ensure their stability and reliability in the ocean environment.

[0113] (5) Chemical engineering

[0114] Catalyst protection: In chemical reactions, the protection of metal catalysts is an important issue. The water-soluble material encapsulation technology of the present invention can be used to protect catalysts, extend their service life, and improve the reaction efficiency.

[0115] Chemical sensors: Developing an encapsulation technology for chemical sensors, using the intelligent response characteristics of water-soluble materials to achieve highly sensitive detection of specific chemical substances.

[0116] (6) Materials science

[0117] Intelligent Materials: Develop intelligent responsive materials, such as water-soluble materials sensitive to temperature, pressure, and pH value, for the preparation and application of intelligent materials to achieve the self-adaptive and self-repair functions of materials.

[0118] Nanomaterials: Combine nanotechnology to develop nanoscale water-soluble encapsulation materials for the protection and release of nanomaterials, improving the stability and application effect of nanomaterials.

[0119] (7) Biomedicine

[0120] Drug Release: Utilize the intelligent responsive characteristics of water-soluble materials to develop a system for drug release, achieving timed and quantitative drug release and improving the therapeutic effect of drugs.

[0121] Biosensors: Develop sensors for biomedical detection, using water-soluble material encapsulation technology to protect the sensors and ensure their stability and reliability in vivo.

[0122] (8) Aerospace

[0123] Space Environment Protection: In the aerospace field, the water-soluble material encapsulation technology of the present invention can be used to protect equipment and materials from radiation and corrosion in the space environment, extending the service life of the equipment.

[0124] Space Resource Utilization: Develop technologies for space resource utilization, such as gas storage and conversion in space, and utilize chemical reactions during the formation of hydrates to achieve efficient resource utilization.

[0125] In summary, the water-soluble material encapsulation technology of the present invention has broad application prospects. It not only has important applications in the fields of carbon dioxide sequestration and industrial waste gas treatment but can also be extended and applied in other fields. Through these applications, the applicability and practicality of the present invention can be further improved, providing more possibilities for the development of related technical fields.

[0126] The above content is a further detailed description of the present invention in combination with specific preferred embodiments. It cannot be determined that the specific implementation of the present invention is only limited to these descriptions. For those skilled in the technical field to which the present invention belongs, without departing from the concept of the present invention, several equivalent substitutions or obvious variations can be made, and as long as the performance or use is the same, they should all be regarded as belonging to the protection scope of the present invention.

Claims

1. A method for controllable nucleation of CO2 hydrate, characterized in that, Including: Producing a water-soluble encapsulating material; Coating a reactive metal with the water-soluble encapsulating material and performing a hermetic encapsulation to obtain a reactive metal water-soluble encapsulant; Using the reactive metal water-soluble encapsulant in the process of CO2 sequestration to induce the formation of CO2 hydrate.

2. The CO2 hydrate controllable nucleation method according to claim 1, characterized in that, Also including: During the process of producing the water-soluble encapsulating material, controlling the dissolution rate of the water-soluble encapsulating material in water by regulating at least one of the material components, component ratios, and material thicknesses, so as to control the nucleation induction time when the reactive metal water-soluble encapsulant is used to induce the formation of CO2 hydrate.

3. The CO2 hydrate controllable nucleation method according to claim 1 or 2, characterized in that The water-soluble encapsulating material is a starch-based water-soluble material, and the production steps include: S1. Mixing bone glue and polyvinyl alcohol to obtain a mixture, mixing 5-100 wt% of the mixture with 0-95 wt% of starch and dissolving it in water to prepare a starch-based water-soluble material solution with a concentration of 150-400 g / L, stirring evenly and removing air bubbles; S2. Pouring the solution prepared in step S1 into a predetermined mold and heating to cure and shape the starch-based water-soluble material, and then demolding to obtain the water-soluble encapsulating material with a predetermined shape.

4. The CO2 hydrate controllable nucleation method according to claim 3, characterized in that, The water-soluble encapsulating material is made into a film shape or a capsule shape.

5. The controllable nucleation method of CO2 hydrate according to claim 4, wherein, Also including: Cutting the reactive metal into a shape and size adapted to the water-soluble encapsulating material, then coating the cut reactive metal with the water-soluble encapsulating material, and heating the water-soluble encapsulating material to achieve thermoforming sealing.

6. The CO2 hydrate controllable nucleation method according to claim 5, characterized in that, The temperature for heating and curing and shaping in step S2 is 60-80 °C.

7. The controllable nucleation method of CO2 hydrate according to claim 5, characterized in that, The heating temperature for achieving the thermoforming sealing is 80-100 °C.

8. The controllable nucleation method of CO2 hydrate according to any one of claims 1-7, characterized in that, The reactive metal includes one or a mixture of two or more of magnesium, aluminum, and zinc.

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