Method for optimizing hydrate hydrogen storage based on special MOFs material

Abstract

The invention discloses a method for optimizing hydrate hydrogen storage based on a special MOFs material. In a low-temperature and high-pressure environment, the special MOFs material adsorbs hydrogen in the reaction container and is prevented from reacting with the catalytic gas to generate impurities. The reaction container adopts a double-layer jacket type, a heating system transfers heat energy to heat the container, a temperature sensor is matched with an intelligent control system, the heating power is regulated and controlled to ensure proper temperature rise, and a pressure control system maintains stable pressure. After hydrogen replacement and impurity removal are realized by the change of the adsorption capacity of the special MOFs material, a transmission and regeneration system is started, a reaction container and a regeneration chamber are connected with a transmission device through a pipeline, an impurity-containing material is transferred to the regeneration chamber and is recycled through cooling and vacuum desorption regeneration, and a hydrate generation reaction is performed again after residual hydrogen in the container is cooled. All the systems cooperate to achieve automatic precise operation, the hydrogen storage efficiency is effectively improved, the cost is reduced, the stability is enhanced, and development of the hydrate hydrogen storage technology is promoted.

Description

Technical Field

[0001] The present invention relates to the field of hydrogen storage technology, and in particular to a method for improving the influence of impurities in the low-temperature and high-pressure hydrate hydrogen storage process, improving hydrogen storage efficiency and realizing material recycling by means of metal organic framework (MOFs) materials. Background Art

[0002] With the booming hydrogen energy industry, hydrate hydrogen storage has attracted much attention due to its advantages such as high hydrogen storage density and relative safety. However, when traditional low-temperature and high-pressure hydrate hydrogen storage technology uses carbon dioxide, methane, etc. as catalysts to assist hydrogen in forming hydrates, it is inevitable to produce impurity hydrates. These impurities not only occupy storage space and reduce the effective hydrogen storage capacity, but also easily cause a series of problems such as pipeline blockage and difficulty in subsequent separation and purification, resulting in a significant reduction in hydrogen storage efficiency and rising costs, which seriously restricts the pace of large-scale commercial application of this technology. Therefore, an innovative strategy is urgently needed to overcome the existing bottlenecks and improve the comprehensive efficiency of hydrate hydrogen storage. Summary of the invention

[0003] 1. Core method flow

[0004] Low-temperature and high-pressure adsorption hydrogen storage and impurity avoidance stage: Create a low-temperature and high-pressure environment in a special reaction container (temperature maintained at -20℃ to 0℃, pressure controlled at 5-10MPa), put the pre-treated and activated special MOFs material into it, and simultaneously inject high-purity hydrogen (purity>99.9%). This special MOFs material is specially designed and synthesized, and the surface functional groups and pore structures are adapted to hydrogen adsorption. It shows a strong affinity for hydrogen at low temperature and high pressure, and efficiently absorbs hydrogen and stores it in its own pores. At the same time, due to its chemical stability and unique selectivity, even if catalytic gases such as carbon dioxide and methane are present, they will not react with them to form impurity hydrates, ensuring that the initial hydrogen storage is pure and efficient, as shown in Table 1.

[0005] Table 1 Concentration changes of different types of hydrogen hydrates

[0006]

[0007] Table 1

[0008]

[0009] Temperature replacement and impurity removal stage: Through the built-in heating element of the reaction container (such as resistance wire heating, hot oil circulation heating system, etc.), the system temperature is increased to the high temperature and high pressure range (temperature up to 80℃-120℃, pressure maintained at 10-15MPa) at a predetermined heating rate (0.5-1℃ / min). With the increase in temperature, the adsorption capacity of special MOFs materials for gases such as carbon dioxide and methane increases sharply, far exceeding the adsorption capacity for hydrogen. This characteristic is used, as shown in Table 2.

[0010] Table 2 Adsorption capacity of special MOFs materials for different gases as temperature changes

[0011]

[0012] The special MOFs material replaces and releases the hydrogen stored in the early stage, allowing the hydrogen to fill the reaction space; at the same time, the impurity gases adsorbed and accumulated in the pores of the special MOFs material (trace impurities mixed in the early stage or generated by the reaction) are carried out of the reaction core area along with it, effectively purifying the reaction system and laying a solid foundation for the subsequent high-quality hydrate formation.

[0013] Special MOFs material regeneration and circulation preparation stage: Open the special unloading channel of the reaction vessel, use mechanical transmission (such as screw conveyor, pneumatic conveying device adapted to inert gas purge) to move the special MOFs material saturated with impurity gas out of the reaction zone and place it in an independent regeneration chamber. In the regeneration chamber, after cooling (cooling rate 1-2℃ / min) and vacuum desorption (vacuum degree reaches -0.08MPa to -0.1MPa), the special MOFs material releases the adsorbed carbon dioxide, methane and other gases, restores the initial adsorption activity, and is ready to be put into the circulation process again; at the same time, the impurity gas in the reaction vessel is emptied and cleaned, and after cooling (to -20℃ to 0℃), the hydrogen displaced in the early stage spontaneously undergoes hydrate formation reaction without the participation of catalytic gas. Because the system has been purified, the hydrate formation at this stage is efficient and pure, which significantly improves the hydrogen storage efficiency.

[0014] 2. Design of supporting equipment

[0015] The housing (1) is made of a composite material of titanium alloy and nickel-based alloy. Titanium alloy has high strength, low density, good corrosion resistance and excellent low-temperature resistance, and can effectively resist embrittlement and other problems that may occur in low-temperature environments. Nickel-based alloys are known for their excellent high-temperature resistance, oxidation resistance and corrosion resistance, especially in high-temperature, high-pressure and corrosive media environments. After the two are combined, the housing (1) has excellent high-pressure resistance and corrosion resistance, and can withstand the huge pressure changes generated by the device during operation from low-temperature and high-pressure environments to high-temperature and high-pressure environments, as well as the erosion of various corrosive gases (such as hydrogen, carbon dioxide, methane, etc.) and seawater and other media that may be exposed to ensure that the overall structure of the device is stable and reliable, and operates stably for a long time.

[0016] The heat exchange structure (2) disposed on the surface of the shell includes a plurality of heat exchange pipes with a diameter of 5-10 cm. The diameter design of these pipes is optimized to ensure sufficient heat exchange area to achieve efficient heat exchange, while not affecting fluid flow resistance and heat exchange efficiency due to excessive or small pipe diameters. The pipe layout adopts advanced fluid mechanics design principles to ensure that the heat exchange medium (such as coolant or heating medium) flows evenly and smoothly in the pipe, without obvious flow dead zones and local overheating or overcooling, thereby achieving efficient heat transfer, accurately controlling the temperature in the device, and meeting the strict temperature requirements at different stages of the reaction process, such as quickly providing heat in the heating stage and quickly taking away heat in the cooling stage.

[0017] The opening and closing accuracy of the seawater introduction valve (3) is ±0.1 mm. This high-precision valve can achieve accurate control of the amount of seawater introduced. Whether it is necessary to introduce a small amount of seawater for cooling or other operations, or to introduce a large amount of seawater, the accuracy of the amount of seawater introduced can be guaranteed to avoid the reaction balance and temperature control in the device being affected by too much or too little seawater introduction.

[0018] The filtration purification system (4) has a filtration accuracy of 0.01-0.1 mm, which can effectively remove impurities such as suspended particles, silt, and microorganisms in seawater. The system uses multiple layers of filtration media, such as fine filters, activated carbon adsorption layers, etc., which can grade and filter impurities of different particle sizes and properties, ensuring the high purity of seawater entering the device, preventing impurities from depositing and clogging in the pipeline, or chemically reacting with components and reaction substances in the device, thereby ensuring the normal operation and service life of the device.

[0019] The inner wall of the internal cavity (5) is coated with a boron nitride coating material with a thickness of 0.1-0.5 mm. Boron nitride has extremely high thermal conductivity, and its thermal conductivity coefficient is comparable to or even higher than that of metal. It can quickly and evenly transfer heat to various parts of the internal cavity, ensuring uniform temperature distribution in the reaction system, so that the hydrate formation reaction is carried out under the same temperature conditions, improving the consistency of the reaction and the quality of the product. At the same time, boron nitride has excellent chemical stability. Under extreme temperature (such as low temperature and high pressure to high temperature and high pressure) and pressure conditions, it does not react chemically with hydrates, avoiding interference with the hydrate formation and storage process, and ensuring the purity and stability of the hydrate. In addition, it can also effectively prevent impurities from adhering to the inner wall of the cavity, keep the inner wall surface smooth, reduce the impact of impurities on the reaction, and reduce the equipment maintenance cost and failure risk caused by impurity accumulation.

[0020] Multiple heating conductors (6) made of molybdenum-rhenium alloy are arranged in a distributed and layered manner in the internal cavity (5). Molybdenum-rhenium alloy has a high melting point, high strength, good high-temperature oxidation resistance and excellent corrosion resistance, and is very suitable for use as a heating element in a high-temperature and high-pressure environment. The spacing between two adjacent layers of heating conductors (6) is 2-5 cm. This reasonable spacing design can make the heat evenly distributed in the vertical direction, avoiding local overheating or uneven heating. The number of heating conductors (6) in each layer is 10-20, and they are evenly distributed on each layer plane, ensuring that heat can also be evenly transferred in the horizontal direction, creating a uniform and stable high-temperature and high-pressure environment for hydrate formation, which is conducive to the efficient reaction, improving the hydrate formation rate and quality, and at the same time ensuring that the special MOFs material exerts its adsorption and regeneration properties in a suitable temperature environment.

[0021] The hydrogen injection pipe (7) is made of polyimide with a wall thickness of 3-5 mm. Polyimide is a high-performance polymer material with the characteristic of high permeability to hydrogen, which can ensure that hydrogen can quickly and smoothly pass through the pipeline into the reaction vessel during the injection process, reducing the transmission resistance and pressure loss of hydrogen in the pipeline. At the same time, it has excellent high-pressure resistance and can withstand the high-pressure environment in the device, ensuring that the pipeline will not break or deform under the action of high-pressure hydrogen, thereby ensuring the safety of the hydrogen injection process. In addition, polyimide has stable chemical properties, does not react chemically with hydrogen, and will not affect the purity of hydrogen, thereby ensuring the quality of hydrogen entering the reaction system, which is conducive to improving the hydrogen storage efficiency and the accuracy of the reaction.

[0022] The flow control valve (8) equipped on the hydrogen injection pipe (7) has an accuracy level of 0.5, and can accurately adjust the flow rate of hydrogen to meet the requirements for accurate control of the hydrogen flow rate in different reaction stages. Whether it is necessary to control a lower flow rate in the initial hydrogen adsorption stage to ensure that the special MOFs material fully adsorbs hydrogen, or when the hydrogen flow rate needs to be adjusted in other stages to optimize the reaction conditions, the flow control valve can provide high-precision flow regulation.

[0023] The mass flow meter (9) has a measurement error within ±0.5% and can accurately monitor the flow rate and total amount of hydrogen in real time. Based on advanced sensing technology, it can quickly respond to changes in hydrogen flow and transmit accurate flow data to the control system. The flow control valve and the mass flow meter work together to form a closed-loop control system. According to the preset hydrogen flow rate and total amount requirements, the opening degree and flow size of the hydrogen injection pipe are accurately controlled to ensure accurate control of the hydrogen injection flow rate and total amount, provide a stable and accurate hydrogen supply for the reaction, help optimize the reaction conditions, and improve the hydrogen storage efficiency and the controllability of the reaction.

[0024] The storage unit of the special MOFs material adding component (20) is used to store the special MOFs material. Its design adopts sealing, moisture-proof, anti-oxidation and other measures to ensure the stability of the special MOFs material during storage. For example, the storage container adopts an inert gas protective atmosphere to prevent the special MOFs material from reacting with oxygen, moisture and the like in the air and losing its activity or performance. The internal structure of the container is reasonably designed to prevent the special MOFs material from being subjected to mechanical damage such as extrusion and collision during storage, thereby ensuring its physical structure is intact, thereby maintaining its good adsorption performance and recycling performance.

[0025] The conveying unit is responsible for conveying the special MOFs material from the storage unit to the internal cavity (5), and its structural design ensures that the conveying process is smooth, efficient and does not damage the material. The conveying method can be pneumatic conveying, spiral conveying or other suitable methods, which can be selected according to the specific layout and requirements of the device. For example, pneumatic conveying uses inert gas as a power source to form a stable airflow in the pipeline, which pushes the special MOFs material to be conveyed in a suspended state, avoiding direct friction and collision with the conveying pipeline; spiral conveying slowly and evenly pushes the special MOFs material forward through the rotation of the spiral blades, and the conveying speed can be adjusted as needed to ensure that the material can accurately reach the designated position of the internal cavity (5) and provide a suitable material supply for the reaction.

[0026] The metering unit can accurately control the amount of special MOFs materials added, and its accuracy can reach a high level, such as an error within ±1% or even higher (determined according to actual needs and technical level). The metering unit uses advanced weighing sensors, volumetric metering devices or other precise metering technologies to accurately control the amount of materials added each time according to the demand for special MOFs materials during the reaction process. In different stages of the reaction, such as the initial adsorption stage, the regeneration and recycling stage, etc., special MOFs materials can be accurately added according to the preset procedures and process requirements to ensure that the concentration and amount of special MOFs materials in the reaction system are always in the best state, thereby achieving precise control of the reaction process, improving reaction efficiency and hydrogen storage effect, while ensuring full utilization of special MOFs materials and reducing waste.

[0027] The nanopores of the nanocomposite film (11) disposed at the mouth of the hydrate output pipe (10) have an average pore size of 1-5 nanometers, a nanopore shape deviation within ±10%, and a distribution density error within ±15%. This high-precision nanopore structure design enables the nanocomposite film to have excellent selective permeability. The diameter of hydrate molecules is relatively large and can be discharged through the nanopores under a certain pressure difference, while the diameter of gas molecules such as hydrogen and carbon dioxide is small and cannot pass through the nanopores, thereby achieving effective separation of hydrates and gases. The precise control of the shape of the nanopores ensures the stability and reliability of its filtering performance, and the high precision of the distribution density ensures that the filtering effect is uniform over a large membrane area, thereby improving the efficiency and purity of the hydrate output, reducing the entrainment of gas impurities, and facilitating the subsequent treatment and utilization of the hydrates.

[0028] The micro-rotating scraper (12) arranged in the hydrate output pipe (10) rotates at a speed of 10-50 revolutions per minute. The blade is made of wear-resistant and corrosion-resistant materials and can continuously scrape off hydrates that may be attached to the pipe wall during the rotation process. As the hydrate flows in the output pipe, due to temperature and pressure changes or other factors, some hydrates may crystallize or deposit on the pipe wall. The continuous action of the micro-rotating scraper can timely remove these attached hydrates to prevent them from accumulating and forming blockages, thereby ensuring the smooth flow of the hydrate output pipe.

[0029] The high-pressure airflow pulse generator (13) has a pulse pressure of 0.1-0.5 MPa and a pulse frequency of 1-10 times / minute, and can generate high-pressure airflow pulses regularly. When the pulsed airflow passes through the hydrate output pipe, it will impact and disturb the hydrate in the pipe, so that the hydrate particles remain in a suspended state, further preventing them from settling and clogging in the pipe. The micro-rotating scraper and the high-pressure airflow pulse generator work together to form a dual anti-clogging mechanism, effectively ensuring the smooth hydrate output process, maintaining the continuous and stable operation of the device, and avoiding production interruptions and equipment damage caused by pipeline blockage.

[0030] The hydrate suction pipeline (21) adopts a multi-layer composite structure, and the inner pipe is a high-strength, wear-resistant and low-temperature resistant nickel-based alloy. The high-strength characteristics of the nickel-based alloy enable it to withstand the pressure of hydrates and seawater, and will not break in high-pressure environments such as the deep sea, ensuring the structural integrity of the pipeline. Its wear resistance can resist the scouring effect of hydrate particles during the flow process, reduce the wear of the inner wall of the pipeline, and extend the service life of the pipeline. The low-temperature resistance ensures that during the temperature change from the low-temperature environment of the seabed to the normal temperature environment of the sea surface, the inner pipe will not become brittle or its performance will decrease due to the decrease in temperature, and it will always maintain good mechanical properties to ensure the safe transportation of hydrates.

[0031] The inner wall of the inner tube is specially treated to be extremely smooth, with a surface roughness that can reach an extremely low level (e.g. less than 0.1 micron), which greatly reduces the flow resistance of hydrates. The smooth inner wall allows hydrates to flow more smoothly in the pipeline, reduces energy loss, improves the efficiency of hydrate suction, and also reduces the risk of hydrate deposition in the pipeline due to excessive flow resistance.

[0032] The high-efficiency insulation material layer (such as polyurethane foam or vacuum insulation board) installed between the inner and outer pipes has extremely low thermal conductivity, which can effectively reduce the impact of temperature changes from the seabed to the sea surface on the stability of hydrates. In the low-temperature environment of the deep sea, the insulation material layer prevents external heat from entering the pipeline, keeping the hydrates in a low-temperature stable state; during the ascent process, even if the surrounding seawater temperature gradually increases, the insulation material layer can slow down the heat transfer speed, avoid premature decomposition of hydrates due to temperature increases, and ensure that the hydrates can reach the sea surface treatment facilities intact.

[0033] The outer pipe uses titanium alloy that is resistant to seawater corrosion. Titanium alloy has excellent seawater corrosion resistance and can resist the erosion of the pipeline by salt, microorganisms, etc. in seawater. It provides structural support for the entire pipeline, protects the internal structure from seawater corrosion damage, and ensures that the pipeline system can operate stably for a long time in a complex submarine environment.

[0034] The connection between pipelines adopts high-strength sealing connection methods, such as welding, flange connection or other special sealing connection technologies to ensure the sealing and strength of the connection parts. When welding, advanced welding technology and high-quality welding materials are used to ensure the quality and strength of the welds and prevent seawater from penetrating into the pipeline or leakage of materials in the pipeline. Flange connections use high-performance sealing gaskets and fastening bolts to ensure a tight and reliable connection.

[0035] Special sealing treatment is performed on the connection parts, such as the use of auxiliary sealing materials such as sealant and sealing tape to further enhance the sealing of the connection parts. At the same time, anti-corrosion treatment is performed on the connection parts to prevent seawater from corroding the connection parts.

[0036] Reinforcement structures are set up at key parts of the pipeline (such as bends and joints), such as increasing the thickness of the pipe wall, using reinforcing rings or special pipe fittings. The bends are designed with large curvature radius to reduce the impact and wear on the elbows during the flow of hydrates. At the same time, reinforcing ribs or sheaths are added to the outside of the elbows to improve their strength and impact resistance. The reinforced structure at the joints ensures the integrity and stability of the pipeline under complex seabed environments and high-pressure conditions, prevents damage to the pipeline due to excessive local force, and ensures the safety, reliability and efficiency of the hydrate suction process.

[0037] The control system (14) includes sensor performance and monitoring functions. The temperature sensor (15) has an accuracy of ±0.5°C and can monitor the temperature changes in the reaction container in real time and accurately, and transmit the temperature data to the intelligent controller (17) quickly and accurately. It uses high-precision thermistors, has the characteristics of fast response and good long-term stability, can accurately measure in complex temperature environments, and provide reliable data support for temperature control.

[0038] The pressure sensor (16) has a sensitivity of 0.1% FS and can keenly sense small changes in pressure. Whether it is pressure fluctuations during the reaction process or switching between different pressure stages, the pressure sensor can detect it promptly and accurately and transmit the data to the control system. It uses a high-precision pressure sensor chip with good anti-interference ability and long-term stability, ensuring the accuracy and reliability of pressure monitoring and providing a key basis for pressure control during the reaction process.

[0039] The gas concentration analyzer (although the specific type is not mentioned in detail in the original text, it plays an important role in the control system) has a detection accuracy of hydrogen, carbon dioxide, methane and other gases at the ppm level, and can accurately analyze the concentration changes of each gas in the reaction system. It uses advanced spectral analysis, electrochemical sensing or other high-precision gas detection technology to monitor the gas concentration in real time, providing important data support for the material balance controller (18) to judge the reaction progress, optimize the reaction conditions and adjust the material input and output, ensuring that the gas concentration in the reaction system is within the appropriate range and ensuring the efficient progress of the reaction.

[0040] The intelligent controller (17) uses advanced control algorithms (such as PID control algorithms, etc.) to accurately control the power of the heating conductor (6) and the cooling efficiency of the heat exchange structure (2) based on the data of the temperature sensor (15) and the preset temperature curve. When the temperature is lower than the preset value, the intelligent controller increases the power of the heating conductor to quickly increase the temperature; when the temperature is higher than the preset value, the flow rate or temperature of the cooling medium of the heat exchange structure is adjusted to accelerate the heat dissipation, so that the temperature in the reaction container is always stable within the set range, ensuring that the reaction is carried out under the optimal temperature conditions.

[0041] The material balance controller (18) accurately controls the operation of the hydrogen injection pipe (7), the seawater introduction valve (3), the hydrate output pipe (10) and the special MOFs material addition component (20) according to the reaction conditions (such as hydrogen consumption, hydrate formation, special MOFs material adsorption state, etc.) and the data of multiple sensors such as the gas concentration analyzer, the temperature sensor, and the pressure sensor. For example, the hydrogen injection amount is controlled according to the change of hydrogen concentration, the opening and flow rate of the hydrate output pipe are adjusted according to the hydrate formation situation, and the addition and unloading operations of the special MOFs material are controlled according to the adsorption and regeneration state of the special MOFs material, so as to ensure the material balance and reaction efficiency in the reaction system, realize the automatic and intelligent operation of the device, reduce manual intervention, improve production efficiency and product quality, and reduce operation errors and production costs. In addition, the control system also has fault diagnosis, alarm and emergency processing functions, and can monitor the working status of each component in real time. Once an abnormality is found, an alarm signal is immediately issued and the corresponding emergency processing procedures are started to ensure the safe and stable operation of the device.

[0042] 3. Demonstration of the advantages of the invention

[0043] Hydrogen storage efficiency has increased: Through multi-stage regulation of special MOFs materials, the formation of impurity hydrates is avoided and the hydrogen storage path is optimized. Compared with traditional methods, the hydrogen storage efficiency is increased by 30%-50%, and the hydrogen storage capacity per unit volume is significantly increased.

[0044] Material recycling reduces costs: Special MOFs materials and catalytic gases can be recycled, reducing material loss and replenishment costs, and the automation of device operation reduces manual intervention, reducing the overall cost by 40%-60% compared to traditional ones. We simulated the cost of each operation of different traditional materials and special MOFs material devices, as well as the revenue of each operation (assuming a fixed value), and then calculated the payback times (payback times = device cost / (revenue per operation-cost per operation)). By drawing a payback times comparison chart, we can intuitively see that special MOFs material devices pay back faster than traditional material devices, thus reflecting its economic advantages.

[0045] Strong system stability: Continuously purify the reaction system, suppress interference from impurities, cooperate with intelligent temperature and pressure control to reduce the probability of equipment failure, extend the service life of the device, and lay a solid foundation for large-scale industrial applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 The adsorption capacity of special MOFs materials under high pressure environment changes with temperature;

[0047] Figure 2 The density of hydrate changes with temperature under high pressure environment;

[0048] Figure 3This is a comparison chart of hydrogen storage efficiency between special MOFs materials and traditional materials;

[0049] Figure 4 This is a comparison chart of the impurity reduction rate between special MOFs materials and traditional materials;

[0050] Figure 5 This is a comparison chart of the economic advantages of special MOFs materials and traditional materials;

[0051] Figure 6 is the plan view of the reaction device;

[0052] Figure 7 is a reaction flow chart; DETAILED DESCRIPTION

[0053] 1. Device assembly and commissioning: According to the mechanical processing and assembly specifications, assemble the reaction vessel, install the heating and cooling components, lay the material transmission pipeline, and integrate the control system. The whole assembly process is strictly controlled to seal (leakage rate <1×10 -6 Pa·m 3 / s) and component installation accuracy (tolerance ±0.1mm); after completion, calibrate the sensor zero range, test the valve opening and closing logic, verify the heating and cooling power, and conduct a pre-operation test to ensure that the initial performance of the device meets the standards.

[0054] 2. Preparation before reaction: Place a sufficient amount of special MOFs material in the activation equipment (heating treatment with inert gas) for pretreatment and then load it to the injection port for standby; purify the hydrogen source, calibrate the flow and connect it to the injection port; check the quality of the coolant and heating medium reserves; set the initial low temperature and high pressure parameters of the control system and start the cooling system to precool the container.

[0055] 3. Hydrogen storage cycle operation: start hydrogen injection and special MOFs material delivery, follow the process of temperature increase replacement, unloading regeneration, and cooling secondary reaction. At each stage, the control system accurately regulates the operation of the equipment based on sensor feedback, monitors and records hydrogen flow and concentration, special MOFs material adsorption status, temperature and pressure curves and other data throughout the process, promptly investigates and handles abnormalities, ensures smooth and efficient circulation, and continuously improves hydrogen storage efficiency.

[0056] 4. Regular maintenance: Regularly (monthly / quarterly) disassemble and check valve seals, clean pipes, calibrate sensor accuracy, and test the structural properties of special MOFs materials (specific surface area, pore volume, etc.), replace worn parts as needed, and replenish special MOFs materials to maintain long-term and stable operation of the device.

Claims

1. A method for optimizing hydrate hydrogen storage based on special MOFs materials, characterized in that: The following steps are involved: Step 1, pre-treating the special MOFs material and placing it in a reaction container, so that the special MOFs material absorbs hydrogen and stores it under a low temperature and high pressure environment, and does not react with catalytic gases such as carbon dioxide and methane to form impurity hydrates; Step 2: Raise the temperature of the reaction environment to high temperature and high pressure, so that the special MOFs material can adsorb gases such as carbon dioxide and methane and replace hydrogen, while taking out impurity gases; Step 3, the special MOFs material that adsorbs impurity gases is moved to a regeneration chamber, and regenerated by cooling and vacuum desorption operations and then recycled for reaction; Step 4, after the residual hydrogen in the reaction container is cooled, a hydrate formation reaction is carried out in the absence of a catalytic gas.

2. The method for optimizing hydrate hydrogen storage based on special MOFs materials according to claim 1, characterized in that: The special MOFs material is a ZIF-8@GO composite material, and its preparation includes the following steps: Step 1, preparation of ZIF-8: weigh 1.9 g zinc nitrate hexahydrate and 0.7 g dimethylimidazole and dissolve them in 80 ml DMF, stir and dissolve them, place them in a polytetrafluoroethylene reactor and react at 140°C for 24 h, cool to room temperature, wash with chloroform, seal and soak for 3 days, take the upper white crystals, wash with DMF several times and dry at 110°C for 12 h; Step 2, GO preparation: Concentrated H2SO4, concentrated HNO3, natural worm graphite, K2S2O8, P2O5, K2MnO4, H2O2, HCl and other reagents were mixed, stirred, diluted, washed, centrifuged and other operations were performed in a specific order and conditions, and calibrated to prepare 2 mg mL -1 GO solution; Step 3, preparation of ZIF-8@GO composite material: controlling the mass ratio of GO and ZIF-8, adding a certain mass fraction of GO into DMF by ultrasonic stirring and dispersion, and then adding it into the ZIF-8 preparation solution.

3. The method for optimizing hydrate hydrogen storage based on special MOFs materials according to claim 1, characterized in that: The low-temperature and high-pressure environment has a temperature of -20°C to 0°C, and a pressure of 5-10MPa; the high-temperature and high-pressure environment has a temperature of 80°C to 120°C, and a pressure of 10-15MPa.

4. The method for optimizing hydrate hydrogen storage based on special MOFs materials according to claim 1, characterized in that: The heating method is any one or a combination of resistance wire heating and hot oil circulation heating system, and the heating rate is 0.5-1°C / min; the cooling rate of the cooling operation is 1-2°C / min, and the vacuum degree of vacuum desorption reaches -0.08MPa to -0.1MPa.

5. The method for optimizing hydrate hydrogen storage based on special MOFs materials according to claim 1, characterized in that: The special MOFs material can also be a material with special adsorption properties such as MIL-101 and UiO-66, and its preparation method can be adjusted accordingly.

6. The method for optimizing hydrate hydrogen storage based on special MOFs materials according to claim 1, characterized in that: The heating method can also be steam heating or a combination of multiple heating methods; the sensor solution can use optical fiber sensors or other sensor products with equal or higher accuracy.

7. A device for implementing the method according to claim 1, characterized in that: include: (1) Reaction vessel body: double-layer jacketed stainless steel pressure-resistant tank structure, with thermal insulation materials filled between the inner and outer layers, the inner tank body withstanding pressure > 15MPa, adapting to the temperature range of -50°C to 150°C, the interface valve is well sealed, and is equipped with a hydrogen injection port, a special MOFs material delivery port, a hydrate and impurity discharge channel, a special MOFs material discharge port and a valve; (2) Heating and cooling system: an integrated electric heating rod array and a low-temperature coolant circulation pipeline are used to control the temperature of the reaction vessel in conjunction with an intelligent temperature control module; (3) Special MOFs material transmission and regeneration system: including screw conveyor, regeneration chamber, vacuum pump, cooling coil and pneumatic conveying pipeline to realize the transportation, regeneration and recycling of special MOFs materials; (4) Control system: It consists of high-precision temperature sensors, pressure sensors, gas concentration analyzers and programmable logic controllers to monitor and control the operation of the device.

8. The device according to claim 7, characterized in that The reaction vessel body is made of corrosion-resistant materials, and is stable for a long time in a specific gas and hydrate environment without corrosion and deformation; the transmission components of the special MOFs material transmission and regeneration system are made of wear-resistant and corrosion-resistant materials; the control system has the functions of automatic parameter adjustment, fault diagnosis, alarm and emergency processing.

9. The device according to claim 7, characterized in that The device can be used in other gas separation fields besides hydrogen storage, such as separating carbon dioxide and methane from mixed gases; it can also be used in other chemical process that require precise control of temperature, pressure and gas adsorption and desorption, such as gas purification, pretreatment of chemical reaction raw materials, etc.

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