Hollow glass microsphere for high-pressure hydrogen storage as well as preparation method and application of hollow glass microsphere

Abstract

The invention discloses a hollow glass microsphere for high-pressure hydrogen storage as well as a preparation method and application thereof, the hollow glass microsphere is of a hollow structure, and the shell wall of the hollow glass microsphere comprises the following components in percentage by weight: 58-86% of silicon dioxide, 1-25% of boron oxide and 6-12% of sodium oxide. The hollow glass microspheres can be prepared on a large scale, and more importantly, the performance, including density, strength, particle size, wall thickness and the like, of the hollow glass microspheres can be regulated and controlled, so that the hollow glass microspheres are more suitable for the field of high-pressure hydrogen storage, and the quality and hydrogen storage efficiency of the hollow glass microspheres are improved.

Description

Technical Field

[0001] This invention belongs to the field of high-pressure hydrogen storage technology, and in particular, relates to a hollow glass microsphere for high-pressure hydrogen storage, its preparation method, and its application in high-pressure hydrogen storage. Background Technology

[0002] Hydrogen energy, as an ideal clean energy source, produces only water as a combustion product when burned with oxygen, making it completely clean and environmentally friendly. The calorific value of hydrogen combustion is 142.2 MJ / kg, approximately three times that of gasoline and six times that of coal. In the hydrogen energy system, hydrogen production technology is relatively mature, but hydrogen storage and transportation are prerequisites for large-scale application. Gaseous hydrogen occupies a large space and has low storage efficiency. Currently, high-pressure hydrogen storage cylinders are used for gaseous hydrogen storage, with pressures reaching 30-70 MPa, placing high demands on the cylinders and resulting in high costs. Liquid hydrogen has a high volumetric energy density, but its boiling point is -252.9℃. Liquefying gaseous hydrogen requires high energy, and the temperature difference with room temperature is approximately 280℃, necessitating stringent insulation measures, thus increasing costs.

[0003] Hollow glass microspheres are micron-sized hollow spherical powders, primarily composed of borosilicates. Hydrogen storage using hollow glass microspheres involves injecting high-pressure hydrogen gas through the shell into the cavity of the microsphere, releasing the high-pressure hydrogen when needed. Even if a small number of microspheres break during hydrogen storage and transportation, safety is not compromised. Therefore, high-pressure hydrogen storage using hollow glass microspheres is a highly promising technology. However, existing hollow glass microspheres for high-pressure hydrogen storage suffer from limitations such as limited storage pressure and short storage life. Furthermore, some current preparation methods are unsuitable for large-scale production of high-pressure hydrogen storage hollow glass microspheres, while methods capable of large-scale production produce hollow glass microspheres unsuitable for hydrogen storage applications. Therefore, developing a hollow glass microsphere more suitable for high-pressure hydrogen storage and capable of large-scale production is a highly challenging and promising research topic. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides hollow glass microspheres suitable for high-pressure hydrogen storage, and also provides a method for large-scale preparation of the microspheres. When used for high-pressure hydrogen storage, the microspheres exhibit low density, high strength, and a high diffusion rate during hydrogen filling, while also possessing high mass hydrogen storage efficiency.

[0005] Specifically, the present invention provides the following technical solution:

[0006] A hollow glass microsphere, particularly suitable for high-pressure hydrogen storage, specifically, the hollow glass microsphere has a hollow structure, and the shell wall of the hollow glass microsphere comprises 58-88% (by weight) silicon dioxide, 1-25% (by weight) boron oxide and 6-12% (by weight) sodium oxide, based on a mass percentage of 100%.

[0007] According to an embodiment of the present invention, the content of silicon dioxide is any value within the range of 58% (by weight), 60% (by weight), 65% (by weight), 70% (by weight), 75% (by weight), 80% (by weight), 85% (by weight), 86% (by weight), or any combination of the above values.

[0008] According to an embodiment of the present invention, the boron oxide content is any value within the range of 1% (by weight), 1.2% (by weight), 1.4% (by weight), 1.6% (by weight), 1.8% (by weight), 2% (by weight), 2.2% (by weight), 2.4% (by weight), 2.6% (by weight), 2.8% (by weight), 3% (by weight), 3.2% (by weight), 3.4% (by weight), 3.6% (by weight), 3.8% (by weight), 4% (by weight), 6% (by weight), 8% (by weight), 10% (by weight), 16% (by weight), 20% (by weight), 25% (by weight), or any combination of the above values.

[0009] According to an embodiment of the present invention, the sodium oxide content is 6% (by weight), 7% (by weight), 8% (by weight), 8.9% (by weight), 10.1% (by weight), 12% (by weight), or any value within the range of any combination of the above values.

[0010] Studies have found that when the amounts of silica, boron oxide, and sodium oxide in the shell of the hollow glass microspheres are controlled within the above-mentioned range, the microspheres are particularly suitable for high-pressure hydrogen storage in terms of density, strength, hydrogen diffusion rate, and mass hydrogen storage efficiency. Specifically, they have a high diffusion rate when filled with hydrogen and a significantly improved mass hydrogen storage efficiency when used for high-pressure hydrogen storage.

[0011] According to an embodiment of the present invention, the true density of the hollow glass microspheres is 0.20-0.4 g / cm³. 3 .

[0012] According to an embodiment of the present invention, the compressive strength of the hollow glass microspheres is 10-40 MPa.

[0013] According to an embodiment of the present invention, the shell wall of the hollow glass microspheres further includes 0-15% (by weight) calcium oxide. Specifically, the content of calcium oxide is any value within the range of 0% (by weight), 2% (by weight), 6% (by weight), 8% (by weight), 10% (by weight), 12% (by weight), 14% (by weight), 15% (by weight), or any combination of the above values.

[0014] According to an embodiment of the present invention, the shell wall of the hollow glass microspheres further includes one or more of the following: 0-5% (by weight) aluminum oxide, 0-5% (by weight) magnesium oxide, 0-5% (by weight) potassium oxide, and 0-2% (by weight) lithium oxide. Specifically, the contents of aluminum oxide, magnesium oxide, and potassium oxide are 0% (by weight), 1% (by weight), 2% (by weight), 3% (by weight), 4% (by weight), or 5% (by weight), respectively. Specifically, the contents of lithium oxide are 0% (by weight), 0.5% (by weight), 1% (by weight), 1.5% (by weight), or 2% (by weight).

[0015] According to an embodiment of the present invention, the size of the hollow glass microspheres is on the micrometer scale. Specifically, for example, it is 10-200 micrometers, or even 50-150 micrometers.

[0016] According to an embodiment of the present invention, the thickness of the shell wall of the hollow glass microsphere is not less than 1 micrometer, for example, 1.0-3.0 micrometers. Specifically, it can be any value within the range of 1.0 micrometer, 1.1 micrometer, 1.2 micrometer, 1.5 micrometer, 1.6 micrometer, 1.7 micrometer, 1.8 micrometer, 1.9 micrometer, 2 micrometer, 2.5 micrometer, 3.0 micrometer or any combination of the above values.

[0017] According to an embodiment of the present invention, in the hollow glass microspheres, (D90-D10) / D50 < 1. Studies have found that controlling the narrow particle size distribution of the hollow glass microspheres is beneficial for pressure uniformity, and the longer half-life of larger particle sizes is beneficial for extending storage time. Furthermore, simultaneously controlling (D90-D10) / D50 < 1 and the shell wall thickness to be no less than 1 micrometer yields even better results.

[0018] The present invention also provides a method for preparing the above-mentioned hollow glass microspheres, the method comprising the following steps:

[0019] 1) SiO2 and / or silicates are mixed with boron-containing compounds, sodium-containing compounds, optional calcium-containing compounds, optional aluminum-containing compounds, optional magnesium-containing compounds, optional potassium-containing compounds, and optional lithium-containing compounds in a solvent to form a slurry. The mixture is reacted, and then a stabilizing dispersant is added to obtain a slurry.

[0020] 2) The slurry obtained in step 1) is atomized and granulated to obtain hollow glass microsphere precursors;

[0021] 3) The hollow glass microsphere precursor prepared in step 2) is sintered to obtain an intermediate product;

[0022] 4) The intermediate product of step 3) is modified with a coupling agent solution or a waterproofing agent solution to obtain the hollow glass microspheres.

[0023] The present invention also provides the application of the above-mentioned hollow glass microspheres in high-pressure hydrogen storage.

[0024] The present invention also provides a high-pressure hydrogen storage method, the method comprising the following steps:

[0025] S1) The hollow glass microspheres described above are loaded into a high-pressure hydrogen charging device and charged with hydrogen under heating and pressurization conditions.

[0026] According to an embodiment of the present invention, in step S1), the heating temperature is 300-500°C, preferably 320-400°C.

[0027] According to an embodiment of the present invention, in step S1), the pressure applied is 10-200 MPa, preferably 40-150 MPa.

[0028] According to an embodiment of the present invention, in step S1), for example, the hydrogen storage temperature is 27°C (300K), and the hydrogen charging temperature is 327°C (600K). According to the ideal gas law pV = nRT, doubling the temperature doubles the pressure. If hydrogen is charged at 327°C (600K) with a maximum pressure of 60MPa, 60MPa of hydrogen gas is introduced into the hollow glass microspheres. When cooled to room temperature (27°C (300K), the pressure inside the hollow glass microspheres drops to 30MPa. Based on this pressure and the density of the hollow glass microspheres, the mass hydrogen storage efficiency of the hollow glass microspheres can be calculated.

[0029] According to an embodiment of the present invention, in step S1), hydrogen is added in stages; specifically, according to the final required hydrogen filling pressure (denoted as P)... 终 The stamping process is divided into N stages (N is greater than or equal to 2), and the stamping pressure (denoted as P) for each stage is P. 终 / N. With P 终 Taking an example with a pressure of 60 MPa and N equal to 3, this means pressing in three stages, each with a pressure of 20 MPa. Research has found that using a staged hydrogen filling method can ensure that the pressure difference between the inside and outside of the hollow glass microspheres is reduced during the staged hydrogen filling process, thereby improving the survival rate of the hollow glass microspheres during hydrogen filling and preventing them from reaching the required pressure in one go. 终 The pressure caused the hollow glass microspheres to be crushed by the high pressure.

[0030] According to an embodiment of the present invention, in step S1), the hydrogen charging time is 4-12 hours, preferably 6-10 hours.

[0031] According to an embodiment of the present invention, the method further includes the following steps:

[0032] S2) After hydrogen charging is completed, the hollow glass microspheres are cooled to room temperature, and high-pressure hydrogen is stored inside the hollow glass microspheres.

[0033] According to an embodiment of the present invention, the method further includes the following steps:

[0034] S3) The temperature of the hollow glass microspheres filled with hydrogen is raised to 200-400℃ to achieve hydrogen release from the microspheres.

[0035] According to an embodiment of the present invention, the hollow glass microspheres after hydrogen release can be recycled.

[0036] The hydrogen charging and decharging processes of this invention are achieved through concentration gradient diffusion.

[0037] The beneficial effects of this invention are:

[0038] This invention enables the large-scale preparation of hollow glass microspheres. More importantly, it allows for the control of the properties of hollow glass microspheres, including density, strength, particle size, and wall thickness, making them more suitable for high-pressure hydrogen storage and improving the hydrogen storage efficiency of hollow glass microspheres.

[0039] In addition, by controlling the Na2O content in the hollow glass microspheres, this invention prepares hollow glass microspheres with low density, high strength, and a high diffusion rate when filled with hydrogen.

[0040] Furthermore, this invention provides a process for sequential hydrogen filling of hollow glass microspheres, which reduces the pressure difference between the inside and outside of the hollow glass microsphere shell and improves the survival rate of the hollow glass microspheres during the hydrogen filling process. Detailed Implementation

[0041] A method for preparing hollow glass microspheres, the method comprising the following steps:

[0042] 1) SiO2 and / or silicates are mixed with boron-containing compounds, sodium-containing compounds, optional calcium-containing compounds, optional aluminum-containing compounds, optional magnesium-containing compounds, optional potassium-containing compounds, and optional lithium-containing compounds in a solvent to form a slurry. The mixture is reacted, and then a stabilizing dispersant is added to obtain a slurry.

[0043] 2) The slurry obtained in step 1) is atomized and granulated to obtain hollow glass microsphere precursors;

[0044] 3) The hollow glass microsphere precursor prepared in step 2) is sintered to obtain an intermediate product;

[0045] 4) The intermediate product of step 3) is modified with a coupling agent solution or a waterproofing agent solution to obtain the hollow glass microspheres.

[0046] According to an embodiment of the present invention, in step 1), the SiO2 is at least one of fumed silica, precipitated silica, silica sol, silica gel powder, or ultrafine quartz sand powder.

[0047] According to an embodiment of the present invention, in step 1), the silicate is selected from at least one of sodium metasilicate, sodium silicate, potassium sodium silicate, potassium silicate, lithium silicate, or quaternary ammonium silicate.

[0048] According to an embodiment of the present invention, in step 1), the stabilizing dispersant includes at least one of a surfactant and a water-soluble polymer, such as polyethylene glycol, polyacrylamide, polyethylene oxide, or polyvinyl alcohol.

[0049] According to an embodiment of the present invention, in step 1), the boron-containing compound is a water-soluble and / or water-insoluble inorganic salt of boron, for example, selected from at least one of boric acid, borax, and ammonium borate.

[0050] According to an embodiment of the present invention, in step 1), the sodium-containing compound is an inorganic salt of sodium that is water-soluble and / or water-insoluble, for example, selected from at least one of sodium chloride, sodium carbonate, sodium nitrate, and sodium sulfate.

[0051] According to an embodiment of the present invention, in step 1), the calcium-containing compound is a water-soluble and / or water-insoluble inorganic salt of calcium, for example, selected from at least one of calcium chloride, calcium carbonate, calcium hydroxide, calcium nitrate, calcium silicate, and calcium acetate.

[0052] According to an embodiment of the present invention, in step 1), the aluminum-containing compound is an inorganic salt of water-soluble and / or water-insoluble aluminum, for example, selected from at least one of aluminum chloride, aluminum nitrate, aluminum sulfate, and aluminum silicate.

[0053] According to an embodiment of the present invention, in step 1), the magnesium-containing compound is an inorganic salt of water-soluble and / or water-insoluble magnesium, for example, selected from at least one of magnesium chloride, magnesium sulfate, and magnesium nitrate.

[0054] According to an embodiment of the present invention, in step 1), the potassium-containing compound is a water-soluble and / or water-insoluble inorganic salt of potassium, for example, selected from at least one of potassium carbonate, potassium nitrate, potassium sulfate, and potassium hydroxide.

[0055] According to an embodiment of the present invention, in step 1), the lithium-containing compound is an inorganic salt of water-soluble and / or water-insoluble lithium, for example, selected from at least one of lithium nitrate and lithium carbonate.

[0056] According to an embodiment of the present invention, in step 1), the added raw materials, based on a mass percentage of 100%, include 0-30 wt% SiO2, 0-20 wt% silicate, 3-25 wt% compound, and 0.1-2 wt% stabilizer / dispersant.

[0057] Furthermore, the content of SiO2 and silicate solution must be at least one non-zero; the remainder is water.

[0058] The compounds include boron-containing compounds, sodium-containing compounds, optional calcium-containing compounds, optional aluminum-containing compounds, optional magnesium-containing compounds, optional potassium-containing compounds, and optional lithium-containing compounds.

[0059] According to an embodiment of the present invention, in step 1), the pH of the slurry is neutral.

[0060] According to an embodiment of the present invention, in step 1), the solvent is selected from water.

[0061] According to an embodiment of the present invention, in step 1), the temperature of the reaction is 30-80°C; the pressure of the reaction is atmospheric pressure.

[0062] According to an embodiment of the present invention, in step 1), the particle size of the solid particles in the slurry is less than 2 μm.

[0063] According to an embodiment of the present invention, in step 2), spray granulation is performed in a spray granulation device.

[0064] Preferably, the inlet temperature of the spray granulation equipment is 280-400℃, the outlet temperature is 120-180℃, and the centrifugal speed is 12000-18000rpm.

[0065] According to an embodiment of the present invention, in step 3), before sintering, precursors with narrow distributions can be screened out first, and then sintering can be performed. For example, the hollow glass microsphere precursors can be screened out using a supersonic airflow classifier to select precursors with narrow distributions. Studies have found that this treatment is more conducive to obtaining hollow glass microspheres with the above-mentioned distribution and wall thickness.

[0066] For example, step 3) specifically involves: first, passing the hollow glass microsphere precursor through a supersonic airflow classifier to screen out the narrowly distributed precursors; then, sintering is performed to obtain the intermediate product. Preferably, in the narrowly distributed precursors, (D90-D10) / D50 < 1.

[0067] According to an embodiment of the present invention, in step 3), the sintering temperature is 700-1100℃.

[0068] According to an embodiment of the present invention, in step 3), the sintering time is 1-3 hours.

[0069] According to an embodiment of the present invention, in step 4), the amount of coupling agent used is 0.02-2 wt% of the intermediate product.

[0070] According to an embodiment of the present invention, in step 4), the coupling agent is a silane coupling agent, a titanate coupling agent, or an aluminate coupling agent; preferably, it is a silane coupling agent with a double bond, more preferably at least one of methacryloxypropyltrimethoxysilane, vinyltrimethoxysilane, or vinyltriethoxysilane.

[0071] According to an embodiment of the present invention, in step 4), the amount of the waterproofing agent is 0.02-2 wt% of the intermediate product.

[0072] According to an embodiment of the present invention, in step 4), the waterproofing agent is sodium trimethylsilanolate.

[0073] According to an embodiment of the present invention, step 4) specifically includes: the intermediate product of step 3) is modified with a coupling agent solution or a waterproofing agent solution, and then dried to obtain the hollow glass microspheres.

[0074] As an exemplary embodiment of the present invention, the method for preparing the hollow glass microspheres is as follows:

[0075] 1) According to the proportion in the liquid system, 0-30wt% of SiO2 and / or 0-20wt% of silicate solution (the content of SiO2 and silicate solution is at least not 0) and 3-25wt% of compound are prepared into a solution, sol or water slurry with a neutral pH. Then, they are mixed at 30-80℃ and normal pressure, reacted, and then 0.1-2wt% of stabilizer and dispersant are added to homogenize, so as to obtain a homogeneous solution, sol or slurry, and the particle size of the solid particles in the slurry is less than 2 micrometers.

[0076] 2) Preparation of precursor: The slurry prepared in step 1) is fed to the spray granulation equipment by a feed pump and sprayed granulation is carried out under the conditions of inlet temperature of 280-400℃, outlet temperature of 120-180℃ and centrifugal speed of 12000-18000rpm. The powder collected by cyclone is the hollow glass microsphere precursor.

[0077] 3) The hollow glass microsphere precursor prepared in step 2) is first passed through a supersonic air classifier to screen out the narrow distribution precursor; then it is transported to the sintering equipment through a powder feeding device, and a micron-sized intermediate product with a volume float rate of more than 95% can be obtained through a vitrification sintering process at 700-1100℃; that is, unmodified hollow glass microspheres.

[0078] 4) Surface modification: The pH of the aqueous solution of the coupling agent is adjusted to 2-5 with acid, and then sprayed onto the surface of the intermediate product by atomization. After drying, the surface-modified hollow glass microspheres are obtained.

[0079] Alternatively, the waterproofing agent solution can be atomized and sprayed onto the surface of the intermediate product, followed by drying to obtain surface-modified hollow glass microspheres.

[0080] The technical solution of the present invention will be further described in detail below with reference to specific embodiments. It should be understood that the following embodiments are merely illustrative and explanatory of the present invention, and should not be construed as limiting the scope of protection of the present invention. All technologies implemented based on the above content of the present invention are covered within the scope of protection intended by the present invention.

[0081] Unless otherwise stated, the raw materials and reagents used in the following examples are commercially available products or can be prepared by known methods.

[0082] Examples 1-3

[0083] This embodiment provides a hollow glass microsphere that can be used for high-pressure hydrogen storage, which is prepared by a method including the following steps:

[0084] 1) Feed the raw materials according to Table 1 below to prepare a water slurry. Mix it thoroughly with a high-speed mixer at 30°C and normal pressure. Then add 0.3wt% polyethylene oxide stabilizer (based on the total mass of the raw materials added). Grind the mixture with a colloid mill to form a homogenized slurry, so that the particle size of the solid particles in the slurry is at least less than 2 micrometers.

[0085] Table 1 shows the content of each raw material added in Examples 1-3.

[0086] Raw materials / kg Example 1 Example 2 Example 3 precipitate 230 310 230 Borax 36 60 20 Sodium carbonate 44 0 0 Sodium sulfate 0 0 40 Sodium nitrate 0 40 0 calcium hydroxide 20 0 0 Calcium nitrate 0 20 18 potassium nitrate 0 0 4 water 800 1200 800

[0087] 2) The homogenized slurry obtained in 1) is fed into a centrifugal spray dryer. The atomization rapid dehydration drying temperature is 320℃ at the inlet and 160℃ at the outlet to obtain spherical precursor powder with a particle size of 20-100 micrometers.

[0088] 3) The hollow glass microsphere precursor prepared in step 2) is first passed through a supersonic air classifier to screen out the narrow distribution precursor; then it is transported to the sintering equipment through a powder feeding device and vitrified at 900℃ for 2 hours to obtain a micron-sized intermediate product with a volume float rate of more than 95%; that is, unmodified hollow glass microspheres.

[0089] 4) Surface modification: The pH of the aqueous solution of coupling agent vinyltrimethoxysilane (the amount of coupling agent is 1-2 wt% of the intermediate product) is adjusted to 2-5 with acid, and the solution is atomized and sprayed onto the surface of the intermediate product. After drying, the surface-modified hollow glass microspheres are obtained.

[0090] Alternatively, an aqueous solution of sodium trimethylsilanolate (the amount of waterproofing agent is 1-2 wt% of the intermediate product) is atomized and sprayed onto the surface of the intermediate product, followed by drying to obtain surface-modified hollow glass microspheres.

[0091] The shell wall of the hollow glass microspheres in Example 1 contains 81.3% (by weight) silicon dioxide, 2.6% (by weight) boron oxide, 10.1% (by weight) sodium oxide, and 6.0% (by weight) calcium oxide.

[0092] The shell wall of the hollow glass microspheres in Example 2 contains 85.6% (by weight) silicon dioxide, 3.4% (by weight) boron oxide, 8.9% (by weight) sodium oxide, and 2.1% (by weight) calcium oxide.

[0093] The shell wall of the hollow glass microspheres in Example 3 contains 86.8% (by weight) silicon dioxide, 1.6% (by weight) boron oxide, 7.4% (by weight) sodium oxide, 2.6% (by weight) calcium oxide and 1.6% (by weight) potassium oxide.

[0094] The true density, average particle size, volumetric float rate, Na2O content, shell wall thickness, compressive strength, mass hydrogen storage efficiency, and particle size distribution of the hollow glass microspheres in Examples 1-3 were tested. Specific test results are listed in Table 2. As can be seen from the data in Table 2, the central control glass microspheres of this invention possess a compressive strength of not less than 10 MPa and a mass hydrogen storage efficiency of not less than 9.5%, making them a product particularly suitable for high-pressure hydrogen storage.

[0095] Table 2 Performance of Hollow Glass Microspheres in Examples 1-3

[0096] Product Performance Example 1 Example 2 Example 3 <![CDATA[True density g / cm 3 > 0.20 0.25 0.30 compressive strength (MPa) 10 15 20 Average particle size (μm) 120 100 80 Volume float rate % 97 96 95 <![CDATA[Na2O content %]]> 10.1 8.9 7.4 Mass hydrogen storage efficiency % 9.5 10.3 11.5 shell wall thickness 1.6 1.7 1.6 (D90-D10) / D50 0.83 0.91 0.88

[0097] Comparative Example 1-1

[0098] 1) Feed the raw materials according to Table 3 below to prepare a water slurry. Mix it thoroughly with a high-speed mixer at 30°C and normal pressure. Then add 0.3wt% polyethylene oxide stabilizer (based on the total mass of the raw materials). Grind the mixture with a colloid mill to form a homogenized slurry, so that the particle size of the solid particles in the slurry is at least less than 2 micrometers.

[0099] Table 3 shows the addition content of each raw material in Comparative Example 1-1.

[0100] Raw materials / kg Comparative Example 1-1 precipitate 390 Borax 320 Sodium nitrate 95 Magnesium nitrate 30 Calcium nitrate 30 Aluminum nitrate 30 water 1500

[0101] 2) The homogenized slurry obtained in 1) is fed into a centrifugal spray dryer. The atomization rapid dehydration drying temperature is 320℃ at the inlet and 160℃ at the outlet to obtain spherical precursor powder with a particle size of 20-100 micrometers.

[0102] 3) The hollow glass microsphere precursor prepared in step 2) is fed into the sintering equipment via a powder feeding device and vitrified at 900℃ for 2 hours to obtain a micron-sized intermediate product with a volume float rate greater than 95%; that is, unmodified hollow glass microspheres.

[0103] 4) Surface modification: The pH of the aqueous solution of coupling agent vinyltrimethoxysilane (the amount of coupling agent is 1-2 wt% of the intermediate product) is adjusted to 2-5 with acid, and the solution is atomized and sprayed onto the surface of the intermediate product. After drying, the surface-modified hollow glass microspheres are obtained.

[0104] Alternatively, an aqueous solution of sodium trimethylsilanolate (the amount of waterproofing agent is 1-2 wt% of the intermediate product) is atomized and sprayed onto the surface of the intermediate product, followed by drying to obtain surface-modified hollow glass microspheres.

[0105] In the shell wall of the hollow glass microspheres of Comparative Example 1-1, there are 62.7% (by weight) silicon dioxide, 13.6% (by weight) boron oxide, 16.1% (by weight) sodium oxide, 1.9% (by weight) magnesium oxide, 2.4% (by weight) calcium oxide and 3.3% (by weight) aluminum oxide.

[0106] As shown in Table 4, the Na2O content in Comparative Example 1-1 was too high, exceeding 12%, resulting in poor strength of the hollow glass microspheres, making them unsuitable for high-pressure hydrogen storage. Furthermore, due to the lack of a supersonic airflow classifier for screening, its (D90-D10) / D50 ratio was 1.39.

[0107] Table 4 Performance of Hollow Glass Microspheres in Comparative Example 1-1

[0108] Product Performance Comparative Example 1-1 <![CDATA[True density g / cm 3 > 0.20 compressive strength (MPa) 3 Average particle size (μm) 86 Volume float rate % 96 <![CDATA[Na2O content %]]> 16.1 Mass hydrogen storage efficiency % Low strength makes it unsuitable for high-pressure hydrogen storage (D90-D10) / D50 1.39

[0109] Application Examples 1-3

[0110] This application example provides the use of the hollow glass microspheres prepared in the above embodiments in high-pressure hydrogen storage, specifically the hydrogen charging and discharging method in high-pressure hydrogen storage:

[0111] 1) The hollow glass microspheres from Examples 1-3 are loaded into a high-pressure hydrogen charging device and charged with hydrogen at a temperature of 327°C. The pressure difference between the inside and outside of the hollow glass microspheres is reduced by gradually increasing the pressure (the specific pressure increase method is shown in Table 5 below), which can reduce the breakage rate of the hollow glass microspheres. Hydrogen gas diffuses through the wall of the microspheres and enters the interior of the hollow glass microspheres. The hydrogen charging is completed in 6-8 hours.

[0112] Table 5 Hydrogen charging parameters for hollow glass microspheres in Examples 1-3

[0113] Hydrogen charging parameters Application Example 1 Application Example 2 Application Example 3 Room temperature hydrogen storage pressure (MPa) 30 45 70 High temperature hydrogen charging pressure (MPa) 60 90 140 Initial hydrogen charging pressure (MPa) 10 15 20 Gradually increase pressure (MPa) 10 15 20

[0114] 2) After hydrogen filling is completed, the hollow glass microspheres are cooled to room temperature of 27°C, and the high-pressure hydrogen is stored inside the microspheres.

[0115] 3) Transport the hollow glass microspheres filled with hydrogen to the place of use, put them into the hydrogen release device to release hydrogen, and raise the temperature to 350°C to release hydrogen from the microspheres. At this temperature, the hydrogen release rate is about 75%.

[0116] 4) Hollow glass microspheres can be recycled after releasing hydrogen.

[0117] Comparative Application Example 1-1

[0118] Table 6 compares the hydrogen charging parameters of hollow glass microspheres in Application Example 1-1.

[0119] Hydrogen charging parameters Comparative Application Example 1-1 Room temperature hydrogen storage pressure (MPa) 30 High temperature hydrogen charging pressure (MPa) 60

[0120] The hollow glass microspheres from Example 1 were loaded into a high-pressure hydrogen charging device and charged with hydrogen at 327°C using a one-step hydrogen charging method, i.e., directly charging with hydrogen at a pressure of 60 MPa. Due to the excessive pressure, the breakage rate of the hollow glass microspheres obtained in Example 1 was greater than 90% at 60 MPa, meaning that over 90% of the hollow glass microspheres broke under 60 MPa pressure. Therefore, the one-step hydrogen charging method is not suitable for charging hollow glass microspheres.

[0121] The embodiments of the present invention have been described above by way of example. However, the scope of protection of the present invention is not limited to the above embodiments. Any modifications, equivalent substitutions, improvements, etc., made by those skilled in the art within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A hollow glass microsphere, characterized in that, The hollow glass microspheres have a hollow structure, and based on a mass percentage of 100%, the shell walls of the hollow glass microspheres contain 58-86% (by weight) silicon dioxide, 1-25% (by weight) boron oxide, and 6-12% (by weight) sodium oxide.

2. The hollow glass microspheres according to claim 1, characterized in that, The true density of the hollow glass microspheres is 0.20-0.4 g / cm³. 3 . Preferably, the compressive strength of the hollow glass microspheres is 10-40 MPa.

3. The hollow glass microspheres according to claim 1 or 2, characterized in that, The shell wall of the hollow glass microspheres also contains 0-15% (by weight) calcium oxide. Preferably, the shell wall of the hollow glass microspheres further includes one or more of the following: 0-5% (by weight) aluminum oxide, 0-5% (by weight) magnesium oxide, 0-5% (by weight) potassium oxide, and 0-2% (by weight) lithium oxide.

4. The hollow glass microspheres according to any one of claims 1-3, characterized in that, The hollow glass microspheres are in the micrometer range in size. Preferably, the thickness of the shell wall of the hollow glass microsphere is not less than 1 micrometer. Preferably, in the hollow glass microspheres, (D90-D10) / D50<1.

5. The method for preparing hollow glass microspheres according to any one of claims 1-4, characterized in that, The method includes the following steps: 1) SiO2 and / or silicates are mixed with boron-containing compounds, sodium-containing compounds, optional calcium-containing compounds, optional aluminum-containing compounds, optional magnesium-containing compounds, optional potassium-containing compounds, and optional lithium-containing compounds in a solvent to form a slurry. The mixture is reacted, and then a stabilizing dispersant is added to obtain a slurry. 2) The slurry obtained in step 1) is atomized and granulated to obtain hollow glass microsphere precursors; 3) The hollow glass microsphere precursor prepared in step 2) is sintered to obtain an intermediate product; 4) The intermediate product of step 3) is modified with a coupling agent solution or a waterproofing agent solution to obtain the hollow glass microspheres.

6. The application of the hollow glass microspheres according to any one of claims 1-4 in high-pressure hydrogen storage.

7. A high-pressure hydrogen storage method, characterized in that, The method includes the following steps: S1) The hollow glass microspheres described above are loaded into a high-pressure hydrogen charging device and charged with hydrogen under heating and pressurization conditions.

8. The method according to claim 7, characterized in that, In step S1), the heating temperature is 300-500℃. Preferably, in step S1), the pressure applied is 10-200 MPa. Preferably, in step S1), hydrogen is added in stages; specifically, according to the final required hydrogen filling pressure (denoted as P). 终 The stamping process is divided into N stages (N is greater than or equal to 2), and the stamping pressure (denoted as P) for each stage is P. 终 / N. Preferably, in step S1), the hydrogen charging time is 4-12 hours.

9. The method according to claim 7, characterized in that, The method further includes the following steps: S2) After hydrogen charging is completed, the hollow glass microspheres are cooled to room temperature, and high-pressure hydrogen is stored inside the hollow glass microspheres.

10. The method according to claim 7, characterized in that, The method further includes the following steps: S3) The temperature of the hollow glass microspheres filled with hydrogen is raised to 200-400℃ to achieve hydrogen release from the microspheres.