A method for increasing the weight storage capacity of hydrogen hydrate

Abstract

The present invention discloses a method for increasing the weight storage capacity of hydrogen hydrates, comprising: adding a thermodynamic promoter to a hydrate reaction vessel to generate hydrogen hydrates at a lower phase equilibrium pressure and temperature; compounding and adding a kinetic promoter to conduct a hydrogen hydrate kinetic experiment to obtain an optimized concentration of the kinetic promoter; placing it in a water bath of a temperature control system, injecting hydrogen through a gas injection system to change the pressure, diffusing hydrate particles into an aqueous solution through a stirring system, and changing the cooling rate through a temperature control system to control the initial hydrogen hydrate formation rate, thereby increasing hydrogen consumption and increasing weight storage capacity; obtaining the weight storage capacity of hydrogen hydrates through pressure and temperature data. The present invention realizes long-term non-explosive storage; it also greatly accelerates the generation rate of hydrogen hydrates to maximize the weight storage capacity of hydrogen.

Description

Technical Field

[0001] The present invention relates to the field of hydrogen energy storage, and in particular to a method and a device for increasing the weight hydrogen storage capacity of hydrogen hydrates. Background Art

[0002] Hydrogen energy is a very important secondary energy source. It is light in weight, has high energy density, and has a wide range of sources. In addition, hydrogen energy is a clean and environmentally friendly energy source, and is known as the ideal energy source of the 21st century. At this stage, hydrogen energy has become the main direction of new energy development together with renewable energy. The use of hydrogen energy can be divided into three parts: hydrogen production, hydrogen storage, and hydrogen transportation. The premise of hydrogen energy application is hydrogen production, and hydrogen storage is an important link that restricts the development of hydrogen energy. What is currently lacking is a hydrogen storage method with low energy consumption and high safety performance, so efficient and safe hydrogen storage methods have become an important research topic.

[0003] The most studied hydrogen storage technologies include high-pressure gas tank hydrogen storage and low-temperature liquid hydrogen storage. Both technologies face high energy consumption and potential safety hazards of leakage. Some solid hydrogen storage methods, such as metal hydride hydrogen storage and porous material adsorption hydrogen storage, may cause environmental problems for metal hydrides, and have low hydrogen release rates and poor circulation of hydrogen storage materials. Physical adsorption using porous media has high adsorption material costs, low adsorption temperatures, and high energy consumption. Hydrate hydrogen storage is a new type of hydrogen storage technology that is simple to operate, highly safe, and has no negative impact on the environment. In addition, it can easily obtain hydrogen by decomposing hydrates, and the energy consumption required for decomposition is low, and the hydrogen storage capacity is also considerable. The generated hydrogen hydrates can be stored at a pressure lower than the pressure at which the hydrates are generated, which can achieve higher pressure generation and low pressure storage, making it easier to transport hydrogen energy. However, the pressure range required for the generation of hydrogen hydrates is still relatively high, and the hydrogen storage capacity of the hydrate method is still at a theoretical value, and the experimental hydrogen storage capacity needs to be increased. Summary of the invention

[0004] In order to solve the technical problems of how to reduce the hydrogen hydrate formation pressure, accelerate the hydrogen hydrate formation rate and increase the weight hydrogen storage capacity of hydrogen hydrate, the primary purpose of the present invention is to provide a method for increasing the weight hydrogen storage capacity of hydrogen hydrate.

[0005] Another object of the present invention is to provide a device for realizing the above-mentioned method of increasing the weight hydrogen storage capacity of hydrogen hydrate.

[0006] The present invention is achieved through the following technical solutions:

[0007] A method for increasing the weight hydrogen storage capacity of hydrogen hydrates comprises the following steps:

[0008] S1. Adding a thermodynamic promoter into a hydrate reaction vessel of a hydrate formation system to generate hydrogen hydrate at a lower phase equilibrium pressure and temperature;

[0009] S2, compounding and adding a kinetic promoter to conduct a hydrogen hydrate kinetic experiment to obtain an optimized concentration of the kinetic promoter;

[0010] S3, placing the hydrate reaction container in a water bath of a temperature control system, injecting hydrogen through a gas injection system to change the pressure, diffusing the hydrate particles into the aqueous solution through a stirring system, and changing the cooling rate through a temperature control system to control the initial hydrogen hydrate formation rate, thereby increasing the hydrogen consumption and improving the weight hydrogen storage capacity;

[0011] S4. Obtain the weight hydrogen storage capacity of hydrogen hydrate by collecting pressure and temperature data from a data acquisition system.

[0012] In some embodiments, in step S1, the thermodynamic promoter is selected from a gaseous thermodynamic promoter or a liquid thermodynamic promoter; wherein the gaseous thermodynamic promoter is selected from propane C3H8 or carbon dioxide CO2; the liquid thermodynamic promoter is selected from one or more of tetrahydrofuran THF, 1,3-dioxolane DIOX, cyclopentane CP, tetrabutylammonium bromide TBAB, and tetrabutylammonium nitrate TBANO3.

[0013] In some embodiments, in step S1, the lower phase equilibrium pressure is 0.3 MPa-13.3 MPa, the temperature is 277.6 K-284.6 K; and the stoichiometric concentration of the thermodynamic promoter is 0.1 mol%-6.0 mol%.

[0014] In some embodiments, in step S2, the kinetic promoter is selected from an amino acid kinetic promoter or an amino acid kinetic promoter coupled with a porous medium; wherein the porous medium is selected from one or more of activated carbon, carbon nanomaterials, and graphene; and the amino acid kinetic promoter is selected from one or more of valine, methionine, and leucine.

[0015] In some embodiments, in step S2, the optimized concentration of the amino acid kinetic promoter is 0.01wt%~1wt%, preferably 0.1wt%~0.5wt%, and more preferably 0.3wt%.

[0016] In some embodiments, in step S3, the water bath temperature of the water bath is 273.15K~280K.

[0017] In some embodiments, in step S3, the pressure range of the hydrogen changing pressure is 10 MPa~14 MPa; and the stirring rate of the stirring system is 550 rpm~650 rpm.

[0018] In some embodiments, in step S3, the cooling rate is 0.01 K / min to 0.5 K / min.

[0019] In some embodiments, in step S4, the weight hydrogen storage capacity of the hydrogen hydrate is 0.20 wt%~0.30 wt%.

[0020] The present invention also provides a device for increasing the weight hydrogen storage capacity of hydrogen hydrate, comprising:

[0021] A gas injection system for injecting hydrogen and / or oxygen, comprising a high-pressure gas cylinder, wherein the high-pressure gas cylinder and a plunger pump are both connected to a piston container, and a pressure gauge is provided on the piston container;

[0022] A hydrate generation system for generating hydrogen-containing mixed hydrates, comprising a hydrate reaction container connected via the piston container 7 and the plunger pump, wherein the hydrate reaction container is a semi-visible stirred reactor with windows on the top and left and right sides; a CCD camera is arranged on the right side of the window;

[0023] A stirring system for promoting hydrate nucleation, comprising a magnetic rotor and a magnetic stirrer arranged at the bottom of the hydrate reaction vessel;

[0024] A temperature control system for controlling the heating and cooling rate, comprising a water bath in which the hydrate reaction container is placed, and the water bath is connected to a programmable temperature-controlled circulating water bath;

[0025] And a data acquisition system for collecting temperature and pressure data, including a thermocouple and a pressure sensor for acquiring the internal temperature and pressure of the hydrate reaction container.

[0026] The beneficial effects of the present invention compared with the prior art include:

[0027] The present invention firstly adds a thermodynamic promoter at a specific stoichiometric concentration to ensure that the produced hydrogen-containing hydrate has appropriate formation and storage conditions at a relatively low phase equilibrium pressure, and the hydrate method for hydrogen storage can achieve long-term non-explosive storage; then a kinetic promoter is compounded and added and its concentration is optimized; and then the initial hydrogen hydrate formation rate is controlled by changing the cooling rate, which can greatly accelerate the hydrogen hydrate generation rate and maximize the weight hydrogen storage capacity.

[0028] In some embodiments, the present invention provides three viewing windows on the hydrate reaction vessel of the hydrate generation system, so that the growth morphology changes of the sides and top of the hydrate crystals can be observed. The temperature changes at different positions in the hydrate reaction vessel can be simultaneously measured through the thermocouples provided in the data acquisition system to determine the effect of the hydrate reaction exothermicity on the temperature. The reactor device of the hydrate reaction vessel is provided with stirring, and the gas-liquid contact area can be increased by stirring, thereby accelerating the generation of hydrogen hydrates and increasing the weight hydrogen storage capacity.

[0029] Other beneficial effects of the embodiments of the present invention will be further described below. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 is a flow chart of a method for increasing the weight hydrogen storage capacity of hydrogen hydrates proposed in an embodiment of the present invention;

[0031] Figure 2 is a schematic diagram of a device for increasing the weight hydrogen storage capacity of hydrogen hydrates proposed in an embodiment of the present invention;

[0032] Figure 3a is a longitudinal cross-sectional view of a reaction container according to an embodiment of the present invention;

[0033] Figure 3b is a top view of a reaction container according to an embodiment of the present invention;

[0034] Figure 4 Schematic diagram of hydrogen consumption under different valine concentrations and tetrahydrofuran in an embodiment of the present invention;

[0035] Figure 5 Schematic diagram of weight hydrogen storage capacity under different valine concentrations and tetrahydrofuran in an embodiment of the present invention;

[0036] Figure 6 is a schematic diagram comparing weight hydrogen storage capacity under different hydrogen and tetrahydrofuran hydrate systems in an embodiment of the present invention;

[0037] The reference numerals are as follows:

[0038] 1- hydrate reaction vessel, 2- viewing window, 3- water bath, 4- magnetic rotor, 5- magnetic stirrer, 6- programmed temperature circulating water bath, 7- piston container, 8- plunger pump, 9- high-pressure gas cylinder, 10- pressure gauge, 11- thermocouple, 12- pressure sensor, 13- data acquisition system, 14- CCD (charge coupled device) camera. DETAILED DESCRIPTION

[0039] The present invention is further described below with reference to the accompanying drawings and in combination with preferred embodiments. It should be noted that the embodiments and features in the embodiments of the present application can be combined with each other without conflict.

[0040] It should be noted that the directional terms such as left, right, up, down, top, and bottom in this embodiment are merely relative concepts or are based on the normal use status of the product, and should not be considered as restrictive.

[0041] How to reduce the pressure of hydrogen hydrate formation, speed up the rate of hydrogen hydrate formation and increase the hydrogen storage capacity are the keys to solving the problem of hydrogen storage by hydrate method.

[0042] The embodiment of the present invention provides a method for increasing the weight storage capacity of hydrogen hydrate, such as Figure 1 As shown, the following steps are included:

[0043] S1. Adding a thermodynamic promoter into a hydrate reaction vessel of a hydrate formation system to generate hydrogen hydrate at a lower phase equilibrium pressure and temperature;

[0044] The thermodynamic promoter is selected from a gaseous thermodynamic promoter or a liquid thermodynamic promoter; the gaseous thermodynamic promoter is selected from propane C3H8 or carbon dioxide CO2; the liquid thermodynamic promoter is selected from one or more of tetrahydrofuran THF, 1,3-dioxolane DIOX, cyclopentane CP, tetrabutylammonium bromide TBAB, and tetrabutylammonium nitrate TBANO3.

[0045] In some embodiments, the lower phase equilibrium pressure is 0.3 MPa-13.3 MPa, the temperature is 277.6 K-284.6 K; and the stoichiometric concentration of the thermodynamic promoter is 0.1 mol%-6 mol%.

[0046] S2, compounding and adding a kinetic promoter to conduct a hydrate kinetic experiment to obtain an optimized concentration of the kinetic promoter;

[0047] The kinetic promoter is selected from an amino acid kinetic promoter or an amino acid kinetic promoter coupled with a porous medium; the porous medium is selected from one or more of activated carbon, carbon nanomaterials, and graphene; the amino acid kinetic promoter is selected from one or more of valine, methionine, and leucine.

[0048] In some embodiments, in step S2, the optimized concentration of the amino acid kinetic promoter is 0.01 wt% to 1 wt%, preferably 0.1 wt% to 0.5 wt%, and more preferably 0.3 wt%.

[0049] S3, placing the hydrate reaction container in a water bath of a temperature control system, injecting hydrogen through a gas injection system to change the pressure, diffusing the hydrate particles into the aqueous solution through a stirring system, and changing the cooling rate through a temperature control system to control the initial hydrogen hydrate formation rate;

[0050] The water bath temperature of the water bath is 273.15K~280K; the pressure range of the hydrogen pressure change is 10 MPa~14 MPa; the stirring rate of the stirring system is 550 rpm~650 rpm; and the cooling rate is 0.02K / min~0.3 K / min.

[0051] S4. Obtaining the weight hydrogen storage capacity of hydrogen hydrate by collecting pressure and temperature data of a data acquisition system;

[0052] The weight hydrogen storage capacity of hydrogen hydrate is 0.20 wt%~0.30wt%.

[0053] The embodiment of the present invention proposes a device and method for increasing the weight hydrogen storage capacity of hydrogen hydrates, which can increase the hydrogen storage capacity of the hydrate method. Adding thermodynamic promoters such as tetrahydrofuran or 1,3-dioxolane to the generation of hydrogen hydrates can change the phase equilibrium conditions, and generate hydrogen hydrates under conditions of lower phase equilibrium pressure and temperature, wherein the lower phase equilibrium pressure is 0.3 MPa-13.3 MPa and the temperature is 277.6 K-284.6 K. On this basis, kinetic promoter amino acids (valine, methionine, leucine, etc.) are added to accelerate the kinetics of hydrogen hydrate generation, optimize different amino acid concentrations, obtain the optimal concentration, and use different cooling rates to generate hydrates to control the initial hydrogen hydrate formation rate, thereby improving the hydrogen hydrate conversion rate and increasing the hydrogen storage capacity.

[0054] The lower phase equilibrium pressure is 0.3 MPa-13.3 MPa, and the temperature is 277.6 K -284.6 K;

[0055] The method for obtaining different amino acid concentrations is to carry out hydrate kinetic experiments by compounding 5.56 mol% promoter (THF, DIOX, etc.) and amino acids (valine, methionine, leucine, etc.), and the amino acid concentration with short induction time and high hydrogen consumption is the optimal concentration, and the concentration range is 0.01wt%~1wt%, and the specific values ​​are 0.01 wt%, 0.03 wt%, 0.1 wt%, 0.3 wt%, and 1.0 wt%; different cooling rates are set by the water bath temperature control program to control the initial hydrogen hydrate generation rate, 0.02K / min, 0.05 K / min, 0.1 K / min, 0.3 K / min;

[0056] The hydrate weight storage capacity of the hydrogen hydrate prepared by the method and device for increasing the weight storage capacity of hydrogen hydrate according to the embodiment of the present invention can be increased from 0.15 wt% to 0.27 wt%.

[0057] The embodiment of the present invention proposes a method of combining a thermodynamic promoter and an amino acid kinetic promoter and a slow cooling experimental step to accelerate the hydrogen hydrate formation rate, improve the hydrogen hydrate conversion rate, and thus increase the hydrogen storage density. The most important idea is to optimize the amino acid concentration, and at the optimized amino acid concentration, use a slow cooling hydrate formation method to increase the hydrogen hydrate conversion rate and increase the weight hydrogen storage capacity.

[0058] like Figure 2 The figure shows the hydrate generation experimental system involved in the method. The hydrate generation experimental equipment provided by the present invention is a semi-visual device with stirring. The experimental system mainly includes the following systems: gas injection system, hydrate generation system, stirring system, temperature control system and data acquisition system.

[0059] A gas injection system for injecting hydrogen and / or oxygen, comprising a high-pressure gas cylinder 9, wherein the high-pressure gas cylinder 9 and a plunger pump 8 are both connected to a piston container 7, and a pressure gauge 10 is provided on the piston container 7;

[0060] A hydrate generation system for generating hydrogen-containing mixed hydrates comprises a hydrate reaction vessel 1 connected via a piston vessel 7 and a plunger pump 8, wherein the hydrate reaction vessel 1 is a semi-visible stirred reactor having viewing windows 2 on the top and on the left and right sides; a CCD (charge coupled device) camera 14 is placed on the right side of the viewing window 2;

[0061] A stirring system for promoting hydrate nucleation, comprising a magnetic rotor 4 and a magnetic stirrer 5 arranged at the bottom of the hydrate reaction vessel 1;

[0062] A temperature control system for controlling the heating and cooling rate, comprising a water bath 3 in which the hydrate reaction vessel 1 is placed, and the water bath 3 is connected to a programmable temperature-controlled circulating water bath 6;

[0063] and a data acquisition system 13 for collecting temperature and pressure data, including a thermocouple 11 and a pressure sensor 12 for acquiring the internal temperature and pressure of the hydrate reaction container 1, wherein the thermocouple 11 is as follows: Figure 2 As shown in the "T" oval, the pressure sensor 12 is Figure 2 The "P" ellipse is shown.

[0064] The hydrate reaction vessel 1 is as follows Figure 3a and Figure 3b shown. Example

[0065] The steps for using the device for increasing the weight storage capacity of hydrogen hydrate in this embodiment are as follows:

[0066] A high-pressure gas cylinder 9 is connected to a piston container 7, and a pressure gauge (10) is installed on the piston container. In addition, a plunger pump 8 is also connected to the piston container 7. The gas is injected into the hydrate reaction container 1 through the piston container 7 and the plunger pump 8. The hydrate reaction container is a semi-visual stirring reactor. A window 2 is opened on the top and left and right sides of the hydrate reaction container. A CCD camera 14 is arranged on the right side of the window 2 to better observe the evolution of the hydrate crystal morphology. The magnetic rotor 4 is placed at the bottom of the hydrate reaction container. The hydrate reaction container 1 is placed in a water bath 3 to achieve a heat preservation effect. The water bath 3 is connected to a program-controlled temperature circulating water bath 6 to control the temperature of the hydrate reaction container and maintain the temperature stable. The water bath is placed on the stirring container. The temperature and pressure inside the reactor are collected by a thermocouple 11 and a pressure sensor 12 respectively, and then reflected on a data acquisition system 14. The thermocouple 11 is as shown in FIG. Figure 2 As shown in the "T" oval, the pressure sensor 12 is Figure 2 The "P" ellipse is shown.

[0067] Based on this device, this embodiment proposes a method for increasing the weight hydrogen storage capacity of hydrogen hydrate, the steps are as follows:

[0068] In H2 (hydrogen) hydrate, a thermodynamic promoter is added to reduce the hydrogen hydrate formation pressure. The concentration of the thermodynamic promoter can be selected to be a stoichiometric concentration of 0.1 mol%~6 mol%, preferably 5.56 mol%. In addition, an amino acid kinetic promoter is added on the basis of the thermodynamic promoter. Under the synergistic effect of the two promoters, the gas consumption value of hydrogen hydrate is further increased. Then the kinetic promoter is optimized to accelerate the hydrogen hydrate formation rate and increase the weight hydrogen storage capacity. The thermodynamic promoters include tetrahydrofuran (THF), 1,3 dioxolane (DIOX), and cyclopentane (CP). The kinetic promoters include amino acids (valine, methionine, leucine, etc.). Under the optimal kinetic promoter, the initial hydrate formation rate is also controlled by changing the cooling rate, thereby increasing the hydrogen hydrate conversion rate and increasing the weight hydrogen storage capacity.

[0069] The cooling rate ranges from 0.01K / min to 0.5 K / min, and the specific values ​​are 0.3K / min, 0.1K / min, 0.05K / min, and 0.02K / min.

[0070] This embodiment increases the hydrogen storage capacity by generating hydrogen hydrates. The decomposition products of the produced hydrogen hydrates are only water molecules and hydrogen, and do not contain other substances that pollute the environment. The experimental technology is environmentally friendly and harmless to the environment. In addition, the reactor used in the hydrate preparation process has three visual windows with stirring, which can achieve the increase in weight hydrogen storage capacity and explain the mechanism of hydrogen hydrate formation.

[0071] In this example, the thermodynamic promoter can be liquid or gas. The gaseous thermodynamic promoters include propane (C3H8) and carbon dioxide (CO2). The liquid thermodynamic promoters include cyclopentane (CP), 1,3-dioxolane and organic salts: tetrabutylammonium bromide (TBAB) and tetrabutylammonium nitrate (TBANO3). The kinetic promoter is not limited to amino acids, and porous media can also be selected, such as activated carbon, carbon nanomaterials, and graphene. The effects of coupling different thermodynamic promoters with porous media on the kinetics of hydrogen hydrate formation are explored.

[0072] The method for increasing the weight hydrogen storage capacity of hydrogen hydrates proposed in this embodiment can also be used to study the influence of the synergistic effect of different thermodynamic promoters and kinetic promoters on the kinetics of hydrogen hydrate formation, and optimize different types of kinetic promoters, so as to obtain the ratio of kinetic promoters that achieves the maximum promoting effect on the kinetics of hydrate formation.

[0073] This embodiment uses a method of changing the cooling rate through a programmed temperature-controlled circulating water bath to control the initial hydrate formation rate, and under the action of stirring, the hydrate particles are dispersed in the gas-liquid two phases, rather than forming a hydrate layer accumulated at the gas-liquid interface, which hinders further contact between hydrogen and water.

[0074] Experimental example:

[0075] like Figure 1 and Figure 2 As shown, the hydrate reaction vessel 1 is cleaned and dried, and then 30 ml of a mixed solution of a thermodynamic promoter and a kinetic promoter (THF and valine mixed solution) is injected, the hydrate reaction vessel 1 is covered with a lid, and is placed in a water bath 3;

[0076] Then adjust the initial temperature of the water bath 3 to 9.6°C, open the valve connected to the high-pressure gas cylinder 9, and inject H2 to 1MPa through the gas injection system to purge the reaction vessel 3 times;

[0077] Slowly inject H2 to 12.0 MPa. When the temperature stabilizes at 9.6 °C, turn on the magnetic stirrer 5 and set the speed to 600 r / min.

[0078] Then the water bath temperature was cooled from 9.6°C to 1°C at a cooling rate of 0.05 K / min. After it dropped to 1°C, the temperature was maintained constant. Hydrates were continuously generated during the cooling process.

[0079] When the pressure drop of the hydrate reaction vessel 1 is less than 0.01 MPa / h, it indicates that the hydrate formation is basically completed. At this time, the water bath temperature is increased to 9.6°C at a heating rate of 0.15 K / min to decompose the hydrate by thermal stimulation.

[0080] The pressure and temperature data can be used to analyze the H2 consumption and weight hydrogen storage capacity.

[0081] like Figure 4 As shown, the stoichiometric concentration of THF in this experimental example is a fixed value of 5.56 mol%, and the maximum value of hydrogen consumption is 31.74 v / v.

[0082] When valine was not added, the hydrogen consumption value was 13.93 v / v, and as the valine concentration increased from 0.01 wt % to 0.3 wt %, the gas consumption value increased from 20.94 v / v to 31.74 v / v;

[0083] When the mass fraction of valine increased to 1.0 wt%, the hydrogen consumption value decreased to 21.75 v / v.

[0084] By comparing the hydrate induction time and hydrogen consumption with and without the kinetic promoter valine, it can be found that the addition of valine can reduce the hydrate induction time, and with the increase of valine concentration, the hydrate induction time can show a trend of being continuously shortened.

[0085] like Figure 5 As shown, the specific data of valine concentration are 0.01 wt%, 0.03 wt%, 0.1 wt%, and 0.3 wt%, respectively, and the corresponding specific data of weight hydrogen storage capacity are 0.18 wt%, 0.23 wt%, 0.26 wt%, 0.27 wt%, and 0.17 wt%, respectively.

[0086] In addition, by analyzing the weight hydrogen storage capacity, it can be found that the synergistic effect of valine and THF further increases the hydrogen storage density. When the valine concentration increases to 0.3 wt%, the hydrogen storage density reaches the maximum.

[0087] Comparative Example:

[0088] like Figure 6 As shown in the figure, compared with other H2-THF hydrate systems (several THF experimental concentrations and different experimental temperatures), it is not difficult to find that when the THF concentration is 5.56 mol% and the temperature is 266.7 K, a higher weight hydrogen storage capacity of 0.28 wt% can be obtained. At the same time, it is found that in the combination of 5.56 mol% THF and 0.3 wt% valine, a higher weight hydrogen storage capacity of 0.27 wt% can be achieved at a higher temperature (274.2 K).

[0089] The embodiments of the present invention have the following beneficial effects:

[0090] 1. The formation conditions of pure hydrogen hydrates are harsh. Hydrogen hydrates can only exist stably when the pressure exceeds 100 MPa and the temperature is lower than 249 K. In the embodiment of the present invention, a thermodynamic promoter of stoichiometric concentration is added to hydrogen hydrates to reduce the phase equilibrium pressure of pure hydrogen hydrates, thereby achieving mild experimental conditions, so that hydrogen-containing hydrates have appropriate formation and storage conditions, and hydrogen storage by hydrate method can achieve long-term non-explosive storage.

[0091] 2. Amino acid is an environmentally friendly kinetic promoter that can improve the kinetics of hydrate formation. This method can further accelerate the formation rate of hydrogen hydrates and improve the conversion rate of hydrogen hydrates under the synergistic effect of thermodynamic promoter (THF or DIOX) and amino acid.

[0092] 3. The hydrate reaction vessel is a semi-visualized stirred reactor device. Stirring can increase the gas-liquid contact area, thereby accelerating the nucleation rate of H2-THF hydrate. Through the windows on the top and sides, the changes in the hydrate crystal morphology can be observed at a deeper level, thus laying a certain foundation for understanding the mechanism of kinetic promoters promoting the growth of hydrogen hydrates.

[0093] 4. The amino acid concentration obtained through experimental optimization has a more obvious kinetic promoting effect on hydrogen hydrates, the hydrate induction time is further shortened, the hydrogen consumption is the highest, and the weight hydrogen storage capacity reaches the maximum value.

[0094] 5. The embodiments of the present invention can control the initial hydrogen hydrate formation rate to allow the hydrate particles to diffuse into the aqueous solution under stirring, rather than aggregating in a layered form at the gas-liquid interface, which may accelerate heat and mass transfer at the interface, increase hydrogen consumption, and thereby increase weight hydrogen storage capacity.

[0095] In some embodiments, the concentrations of different thermodynamic promoters can also be changed. Selecting a low concentration of thermodynamic promoter may allow hydrogen to occupy a large cage, thereby increasing the weight hydrogen storage capacity.

[0096] In some embodiments, other environmentally friendly kinetic promoters (cellulose, starch, etc.) can be selected to be combined with thermodynamic promoters to promote the kinetics of hydrogen hydrate formation.

[0097] In some embodiments, porous media (carbon materials, etc.) may be used to improve the diffusion channels between hydrogen molecules and the liquid phase, thereby increasing the hydrogen hydrate conversion rate.

[0098] The embodiments of the present invention can also be applied to natural gas storage and transportation, hydrate-based seawater desalination technology, carbon dioxide capture and storage, and gas separation.

[0099] The above contents are further detailed descriptions 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 those skilled in the art of the present invention, several equivalent substitutions or obvious variations can be made without departing from the concept of the present invention, and the performance or use is the same, which should be regarded as belonging to the protection scope of the present invention.

Claims

1. A method for increasing the weight storage capacity of hydrogen hydrate, characterized in that: The steps include: S1. Adding a thermodynamic promoter to a hydrate reaction vessel of a hydrate formation system, wherein the thermodynamic promoter is tetrahydrofuran (THF) with a stoichiometric concentration of 0.1 mol% to 6.0 mol%, to generate hydrogen hydrate at a relatively low phase equilibrium pressure and temperature, wherein the relatively low phase equilibrium pressure is 0.3 MPa to 13.3 MPa and the temperature is 277.6 K to 284.6 K; S2, compounding and adding a kinetic promoter to conduct hydrogen hydrate kinetics experiments to obtain an optimized concentration of the kinetic promoter; the kinetic promoter is valine, and the concentration is 0.3 wt%; S3, placing the hydrate reaction container in a water bath of a temperature control system, injecting hydrogen through a gas injection system to change the pressure, diffusing the hydrate particles into the aqueous solution through a stirring system, and changing the cooling rate through a temperature control system to control the initial hydrogen hydrate formation rate, the cooling rate being 0.01 K / min to 0.5 K / min, thereby increasing the hydrogen consumption and improving the weight hydrogen storage capacity; S4. Obtain the weight hydrogen storage capacity of hydrogen hydrate by collecting pressure and temperature data from a data acquisition system.

2. The method for increasing the weight storage capacity of hydrogen hydrate according to claim 1, characterized in that: In step S4, the weight hydrogen storage capacity of the hydrogen hydrate is 0.20 wt%~0.30 wt%.

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