Hydrogen storage and transport system

Abstract

1.1 Storage system for the storage and transport of hydrogen, based on hollow microspheres in whose closed shells metal particles are embedded, which can be heated inductively. 2.1. Various hydrogen storage and transport systems exist, which either have limited storage capacities or require significant energy input, and are therefore generally not economically viable for a broad hydrogen economy. The new system aims to provide large storage capacities with the lowest possible energy consumption. 2.2. The storage system is characterized by the fact that metal, metal alloy, or metal composite particles are embedded in the closed shells of hollow microspheres, which can be inductively heated, thus allowing rapid hydrogen permeation into and out of the hollow spheres even at low temperatures during the loading and unloading process. 2.3. Hydrogen storage and transport system.

Description

[0001] The invention relates to a storage system for the storage and transport of hydrogen, using reversible hydrogen storage elements based on hollow microspheres, in whose closed shells metal, metal alloy or metal composite particles are embedded, which can be inductively heated.

[0002] As part of the global energy transition, hydrogen is increasingly being used as an energy carrier and energy storage medium instead of fossil fuels. To establish a comprehensive hydrogen economy on a large scale, inexpensive, loss-free, and especially energy-loss-free, and safe storage and transport systems for hydrogen are essential. Various options and principles are known for storing hydrogen. For example, hydrogen is stored in large tanks under high pressure, which requires considerable mechanical strength. Furthermore, these are only suitable for mobile use to a limited extent due to the potential danger. Liquid hydrogen is also being stored, which requires suitable and very well-insulated containers. In addition, a great deal of energy is required to liquefy approximately 30% of the calorific value of the hydrogen.Long-term storage is not possible due to the low temperature that cannot be maintained for long and the boil-off effect of around 0.1 to 3% per day, depending on the storage size and thermal insulation properties of the storage tanks. Another known option is storage in the form of hydrides. This requires energy for storage and emptying. The storage capacity is limited and the storage systems are comparatively very heavy and often too expensive for larger storage units. The present invention deals with the possibility of storing hydrogen in microspheres or hollow microspheres, which are also referred to as microballoons or cenospheres. Without taking costs into account, the percentage mass storage capacities in . Fig.Figure 1, based on publication DS1 by Luo et al., shows the different overall storage systems as a function of hydrogen pressure. In addition to these direct hydrogen storage systems, there are also many chemical storage systems, which involve conversion into intermediates such as methanol or ammonia. So-called LOHC compounds (Liquid Organic Hydrogen Carriers), such as N-ethylcarbazole or dibenzyltoluene, are also being extensively investigated. There are also efforts to use purely adsorbent materials such as zeolites, activated carbon, or clay as intermediate storage media. These adsorbent materials have very low hydrogen absorption capacities, and the LOHC compounds themselves are too cost-intensive and require a far too complex reaction infrastructure for hydrogenation and dehydrogenation to be operated economically.

[0003] Hollow microspheres have been produced for approximately 100 years and are used in many industries and applications, sometimes even on a large-scale industrial scale. Large-scale plants were described early on, for example, in publications US2676892A, US2978339A, US3838998A, US4661137A, and US6254981B1 (and their cited documents). Cenospheres are hard and stiff, lightweight, water-resistant, nontoxic, and insulating. This makes them extremely useful for a wide variety of production processes, particularly as fillers. For example, the addition of cenospheres to cement is converted into lightweight concrete, and air-entrained concrete produced in this way also exhibits increased resistance to frost and, in particular, to freeze-thaw salt exposure. More recently, they have also been used as fillers for metals and polymers. They are used in surface technology, the leather and paper industry, the paint and wall plastering industry, and the adhesive and filler industry.Recently, numerous intensive studies have been conducted on the use of hollow microspheres as carrier systems for pharmaceuticals, as described, for example, in publications DS2 and DS3. They are even used as fire protection and firefighting agents. Hollow microspheres filled with tritium and deuterium have gained particular importance as a core component in development efforts for inertial thermonuclear fusion research. Publication DS4 provides a comprehensive overview.

[0004] There are a number of different manufacturing methods for hollow microspheres. These include: Self-forming hollow microspheres in the electrostatically deposited fly ash from coal-fired power plants, as described in publications DS8 and DS9. However, these exhibit a very irregular structure and geometry and are often contaminated with impurities. The spray pyrolysis process, particularly the high-temperature ultrasonic spray pyrolysis process (see also the internet link IL1). The expansion process, as described by way of example in publications DE102016208141A1 and DE102017219692A1. So-called "semiproduct production" is briefly summarized in publication DS5. The liquid droplet method, developed for hydrogen storage by Hendricks et al. and described in publications DS6 and DS7.The sol-gel process, starting from metal alkoxides, predominantly with tetraethyl orthosilicate, is described by Ding and Day in DS10. Individual droplets are then dried at approximately 250°C and finally converted into hollow spheres at approximately 500 to 700°C. The synthesis of hollow silica aerogel spheres by Jang et al. is described in DS11 and DS12. The method combines a droplet generation method with a sol-gel process. Hollow microspheres have also been produced from polymers. They can be produced using emulsion processes or by coating solid template particles (e.g., polystyrene or silica) in liquid suspensions or in fluidized beds. According to DS13, the solid particles act as sacrificial cores and are removed by thermolysis or chemical etching. In medical technology, such polymer-based hollow microspheres are manufactured using a variety of processes.These include the single emulsion technique, the double emulsion technique, the polymerization technique, the normal polymerization, the interfacial polymerization, the phase separation coacervation technique, the spray drying and spray solidification technique, the solvent extraction technique, the quasi-emulsion solvent diffusion technique, as well as wax coating and hot melt coating. These processes are described in more detail in publications DS14 to DS19. Less common processes are based on rotating electrical arcs, described, for example, in publication DS20. Hollow microspheres can also be produced in an argon plasma jet, as described, for example, in publication DS21. In this context, the possibility of producing hollow iron microspheres, as described in publication DS22, should be mentioned here.The production of hollow microspheres using the Verneuil method, i.e., melting in an oxyhydrogen flame, was recently described in publication DS23. Dalai et al. and Gupta et al. show in publications DS31 and DS32 that with increasing grain size of the starting glass powder, the quality, i.e., the achievement of a good spherical shape, decreases. To ensure a better and more uniform spherical shape of the hollow spheres, Lee et al. describe a multiple treatment in a vertical thermal flame treatment (VTF) process of the partially expanded particles in publication DS30.

[0005] Commercially produced hollow glass microspheres were investigated in the late 1970s by Teitel DS24 to DS26 as a possible way to store hydrogen. The hollow spheres had diameters between approximately 25 and 200 µm and shell thicknesses between approximately 1 and 20 µm. At elevated temperatures between approximately 150 and 400°C, the hydrogen permeability of the glass membrane increases significantly, so that it was possible to fill the interior of the hollow spheres with hydrogen of a similar pressure by diffusion at high pressures for sufficient periods of time. After cooling to room temperature at high pressure, the permeability of the hydrogen through the membrane decreases to such an extent that the high pressure and thus the hydrogen content within the hollow sphere could be maintained for long periods of time, even when the external pressure was reduced again to approximately 1 bar (normal pressure). To release the stored hydrogen, the pressurized hollow microspheres are heated again.As part of inertial fusion research in the late 1970s, in which a nuclear fusion reaction was to be triggered in individual glass spheres filled with tritium and deuterium by laser bombardment, Woerner et al. conducted a series of semi-empirical studies in DS27 to understand the properties of hydrogen-filled hollow glass spheres. The manufacturing processes and properties of the hollow spheres were significantly improved and continually refined in the following years. Examples of such systems are described in DE1496573A1, DE2527910A1, DE2455366A1, DE2548446A1, DE2514834, US4391646A, US4211537A, US4302217A, and US4767726A. To fill and empty the hollow microspheres, which on average contain only between 10 and 15 wt.% hydrogen, considerable amounts of heating energy must be used to heat the shell material.For sufficiently rapid hydrogen permeation, temperatures of several hundred °C are necessary. To significantly reduce the heating energy required during the loading and unloading process, document DE102007038779A1 proposes modifying the shell material so that even small temperature increases of a few tens of °C sufficiently increase hydrogen permeability. The shell is made of a metallic material (metal or metal alloy) that exhibits increasing hydrogen permeability at temperatures above 50 °C, although temperatures of up to 300 °C are also intended to be used. To achieve complete emptying even with decreasing internal pressure, heating up to 500 °C is also required, which means that the original goal of low temperatures is not achieved.Particularly suitable metals for forming the shells of the hollow spheres are iron, preferably ferritic or α-iron, martensitic steel, nickel, titanium, palladium, cobalt, and alloys of these metals. To overcome potential strength issues, double-shell systems are proposed. The use of α-iron is presented as an example, with the maximum achievable gravimetric hydrogen storage density, defined as the ratio of the mass of stored hydrogen to the total mass of the hollow sphere, being 3.4 wt.% -H2 under the postulated conditions. In document AT503701A4, supplemented by publications DS28 and DS29, Keding et al. propose a system for storing hydrogen in hollow microspheres in combination with a hydrolysis-sensitive hydride such as sodium borohydride (NaBH4).To ensure the permeability of the hollow microsphere shell by increasing the temperature, a catalyst is additionally applied to the shell surface, which greatly accelerates the exothermic hydrolysis reaction of the hydride precisely at the shell wall. This results in very local heating of the sphere wall, increasing the permeability of the enclosed hydrogen. In addition, further hydrogen is released through the decomposition of the hydride. According to the example in the document, approximately 11.75 wt.% of hydrogen can be released from the mixture used. However, approximately 80% of the released hydrogen is provided by the hydrolysis of the hydride, and only approximately 20% comes from the hollow microspheres at an internal pressure of 700 bar. The weight-based hydrogen content from the hollow microspheres is therefore only approximately 2.35 wt.%.In addition to purely thermal heating of the shell to increase permeability, document US6231642B1 also describes irradiation, for example with infrared radiation. To ensure good radiation absorption in the glass, various metal oxides such as Fe3O4; CoO; NiO; V2O5 or Cr2O3 are added to the glass formulation. The advantage of this system lies in the faster and more temporally compact release of hydrogen. Document US2009242382A1 proposes hydrogen-storing hollow microspheres, which also control gas exchange through radiation, for use in transportation. In this case, the oxides used in the glass formulation include, in addition to a number of elements, primarily the oxides of germanium, titanium, and especially gallium. A composite structure for increasing the tensile strength and permeation resistance during storage, the shell of a hollow microsphere, is described in document US2006030483A1.With regard to safety when handling hydrogen, the inclusion in hollow microspheres shows a number of excellent properties. For example, the Dornier company proposes the use of this system for the production of highly explosion-proof fuel tanks in armoured vehicles in document DE3027631A1.

[0006] The permeation behavior of hydrogen in various metals has been extensively investigated. For the ferromagnetic metals most commonly used in the present invention, such as iron and nickel (and their alloys), the behavior is investigated as examples in document DS33. It can be seen that the hydrogen permeability in nickel is approximately ten times lower than that of iron at low temperatures. At higher temperatures (approximately 700°C), the permeabilities become more similar. This means that nickel exhibits a better permeability change with increasing temperature. According to these studies, the behavior of pure nickel can be almost achieved with an alloy content of just 4.6% nickel in iron. According to document DS34, palladium, like the elements titanium, niobium, vanadium, and tantalum, exhibits significantly better permeability than nickel and iron.Attractively priced alloys with particularly good permeabilities are described in publications DS39, DS35, and DS36. The temperature dependence of hydrogen diffusion or permeability in metals can be described using an Arrhenius approach. According to publications DS37 and DS38 (there, see also [the text].) Many metals, such as iron and the palladium alloy Pd-25Ag, exhibit similar permeabilities. Fig.9; S11) a strong deviation from this general Arrhenius approach below approximately 200°C. For the present invention, the observation that the permeability decreases in the rather small temperature interval between approximately 200°C and room temperature, often by up to two orders of magnitude or more, proves to be particularly advantageous. If the permeability at approximately 300°C of glass is compared to iron and again to palladium, the resulting ratio is approximately 1 / (70-1000) / (20-500), depending on the specific metal type, and averages out to approximately 1 / 450 / 250. This means that, very roughly estimated, iron requires only 1 / 450th of the amount of hydrogen per unit area, and palladium only 1 / 112500th of the amount of hydrogen per unit area, compared to glass, in order to allow equivalent amounts of hydrogen to pass through in the same unit of time and at the same pressure drop.

[0007] Electroless palladium deposition can easily be performed superficially by cementation on less noble elements such as iron or nickel, but this only produces a thin layer of a few thousand angstroms, a so-called "flash." If thicker layers in the µm range are to be deposited, electroless plating baths with a suitable reducing agent must be used. Examples of such baths are described in documents US7678183B2, US7632343B2, US2009044720A1, EP2784182A1, and EP1930472A1, among others.

[0008] To ensure good adhesion between a metal surface and a glass medium, the metal surface must be coated with an adhesion promoter. The IL2 internet link specifically refers to so-called silane adhesion promoters. They typically have the general form R-SiX3, where R represents an organically functionalized residue and X represents a hydrolyzable group, usually an alkoxy group. Through hydrolysis reactions with water, they therefore form silanols of the form R-Si(OH)3. Silanols can enter into condensation reactions with inorganic materials that have OH or COOH groups on their surface, thus forming a stable bond through chemical bonds. Ideally, the Si atoms are integrated into the substrate surface via all three OH groups. The organic group R is often coupled to vinyl, methacrylic acid, epoxy, amino, urea, or thiol groups via a spacer.DE102010002356A1 and its citations list numerous possible examples. Dispersions based on the reaction of a 3-glycidyloxypropylalkoxysilane with an aqueous silica sol are known from EP1773958A1 and US2008 / 0058489. EP1288245A2 discloses compositions from the reaction of an aqueous silica sol with alkyltrialkoxysilanes and an alkoxysilane. In order to reduce VOC pollution of the environment, aqueous, oligomeric silanes, which also include polysiloxanes with corresponding structural elements, as known from the patents EP0675128, EP0953591, EP0716128, EP0716127, EP0832911, EP1031593, WO2007 / 085320, WO2006 / 010388A1, WO2007 / 085339, WO2009 / 030538 and WO2006 / 037380, are often used.In addition to functional silanes and their oligomeric hydrolysates, silicic acid esters such as tetraethylortosilicate and similar compounds, as well as zirconates and titanates, as well as zirconium aluminates and their oligomers, are also frequently used. The most important compounds are titanium tetraisopropylate, titanium tetrabutylate, and zirconium tetrabutylate; less frequently, chelates such as titanium acetylacetonate are also used. The adhesion film is always applied using a sol-gel process, whereby care must often be taken to ensure that the adhesion film is very thin to prevent crystalline precipitation.

[0009] In contrast to the prior art, the permeation behavior or permeability of hydrogen through the base material of the hollow microsphere walls at the elevated temperatures during the loading and unloading process does not play a decisive role in the present invention, but rather the biaxial tensile strength of the shell, or rather the ratio of this to its density. According to the invention, the majority of the hydrogen exchange occurs from the outside to the inside and vice versa through the metal particles embedded in the shell wall. This allows, for example, glass types with significantly higher tensile strengths to be used in glass shells compared to previous ones. In particular, the tensile strength during emptying at high temperatures should be significantly increased compared to the prior art.A further advantage of the invention is that the required loading and unloading temperatures can be reduced by optimizing the number and shape of the particle inclusions. Glass can theoretically achieve tensile strengths of up to approximately 17 GPa according to IL3. Technical glasses, which are widely used in fiberglass materials today and are commercially available, have tensile strengths of approximately 4.89 GPa at room temperature, approximately 4.4 GPa at 370°C, and approximately 2.4 GPa at 530°C according to IL4. These glass types are referred to as S2 glass. An overview of possible applications and their physical and chemical properties can be found, for example, in publication DS40. S2 glasses often belong to the class of magnesia-aluminia-silica glasses, the basic composition of which is described, for example, in the documents WO0242233A2, EP0213715A2, EP2028166A1, and the document DS41.In the patent literature, there are a large number of formulations for glass types that have tensile strengths higher than 4.9 GPa, for example, WO2012052841A1 reports 5350 MPa and US2017101338A1 reports 5583 MPa.

[0010] The production of suitable glass / metal composites represents the cornerstone of the present invention. Methods for their production are widely described in the literature. In addition to composites, fiber components with powder components are frequently described, for example, in document DS42, powder / powder composites are frequently described. Powder metallurgical methods, along with the less frequently used mixing of metal particles into a glass melt, are the most frequently used methods. Krainer et al. describes the basic procedure in document DS43. First, the glass raw material is crushed and ground, usually using ball mills. The resulting glass powder is then divided into three different size fractions using sieves or air separation. The fine fraction is remelted, and the coarse fraction is returned to the grinding process.The fraction with the desired particle size is mixed with metal powder of a suitable particle size and subjected to a vibrating grinding process. The resulting material is then compacted using sufficient pressure. The higher the pressure, and thus the lower the dead volume, the better the sintering process can be carried out. However, there are limits to the pressure; care must be taken to ensure that the metal particles retain their spherical geometry. The annealing process is then initiated at a sufficiently high temperature and for a sufficiently long time. After the sintering process is complete, the material can be further processed, either by extrusion, forging, or grinding into the appropriate powder. Corresponding examples can be found in documents DE3001096A1, CN102912163A, CN110699676A, and CN110699676A. In the latter document, the sintering process is carried out using a discharge plasma sintering process.Special sintering processes include spark plasma sintering (SPS) and selective laser sintering (SLS). Examples can also be found in publication DS44. Glass / iron composites can be found in publications DS45 to DS48. In addition to the powder metallurgy process described above, processes similar to the sol-gel process are also used. These involve precursor solutions similar to liquid water glass, into which the metal powder is stirred and, after drying, melted to form a glass matrix.

[0011] In addition to the state of the art, further aspects must be considered when designing and dimensioning the hollow microspheres according to the invention. These include, first and foremost, the fact that hydrogen is a real gas and not an "ideal gas." Fig.Figure 2a shows the deviation of the compressibility factor Z of hydrogen at different temperatures in relation to pressure compared to the factor 1, which is always constant over all pressure ranges for an ideal gas. This leads to the fact that, as Fig. Figure 2b shows that with increasing pressure, comparatively more pressure is required to achieve correspondingly higher hydrogen densities. Therefore, it makes little sense to use ever-increasing pressures for storage, as the energy losses during compression work increase proportionally. Furthermore, the technical requirements for high-pressure compression become increasingly complex with increasing pressure. Fig.Figure 2c shows the ratio of the compression energy required to the stored calorific value of the hydrogen in percent. Theoretical adiabatic compression is compared to theoretical isothermal compression. The behavior of actual isothermal, multi-stage, and isentropic compression is also shown. According to this, isothermal compression would be the most advantageous, but it requires considerable energy expenditure for cooling processes, making this option obsolete. Multi-stage compression is currently one of the most economical methods. Taking these aspects into account, the optimal pressure range is approximately 1000 bar, plus or minus a few hundred bar. This means that the energy required purely for compression is between 11 and 14% of the calorific value of the hydrogen. For 1000 bar, this results in approximately 12.5%.For an energetic analysis of the state of the art, the amount of energy required to fill and empty the hollow microspheres must also be considered. Furthermore, with the current state of the art, the heat losses absorbed by the pressure vessel during the filling process, which must be designed accordingly solidly at such high pressures, must also be taken into account. With a storage capacity of approximately 10 wt.% hydrogen, the glass mass is 9 times the hydrogen mass, and with approximately 15 wt.% hydrogen, it is 6 times the hydrogen mass. The heat capacity of glass, depending on the type of glass, is between approximately 700 and 900 (J * kg). -1 * K -1 ). Assuming an average heat capacity of 800 (J * kg -1 * K -1) and a temperature increase to approximately 350°C to ensure sufficiently rapid loading and unloading, and a hydrogen storage capacity of 10 wt.%, this results in a heat expenditure of approximately 4.7 MJ for 1 kg of hydrogen, based on current technology, just for heating the glass. This corresponds to approximately 3.9% of the calorific value. Assuming a further 1% for heat loss through pressure vessels, this results in a total loss of approximately 16 to 20% of the calorific value of the stored hydrogen. Transfer and transport costs must be taken into account accordingly.

[0012] The volumetric energy density of hollow hydrogen microspheres depends strongly on the differential pressure they can withstand. The maximum pressure of H2 inside a hollow microsphere depends on the i or r o designated inner and outer radii and the biaxial tensile strength of the shell materials (σ s,max). The tensile strength of the shell material can be reduced by inhomogeneities such as indentations and notches or by inclusions, which are unavoidable according to the invention. Thus, the maximum tensile strength must be additionally multiplied by a weakening factor δ. The weakening factor δ is usually less than 1, but can also be greater than 1. This is postulated, for example, in document DS49. For thin-walled microspheres (ie r o > 5(r o - r i )) is derived from the boiler formula of the P max designated burst pressure expressed as Pmax=2*(σs,max*δ)*(ro−ri)−−−−−−−−−−−−−−−−−−Sf*ro

[0013] During the actual design and manufacture of the storage system, a safety factor S fmust be considered, which typically ranges between 1.5 and 10. For H2 storage applications, this value is often assumed to be 1.5, since the rupture of a microsphere according to Rambach (DS50) does not compromise the integrity of the entire hydrogen storage solution. For cylindrical hollow fibers, the burst pressure is halved.

[0014] During hydrogen loading, the external pressure should be continuously increased to build up an internal backpressure with increasing loading and controlled to prevent the microspheres from collapsing when the difference between internal and external pressure exceeds the buckling pressure. The classical expression for the static buckling pressure P cr for isotropic thin-walled and flat spherical shells under uniform pressure is given by Pcr=2*ES*(ro−ri)2−−−−−−−−−−−−−−−ro2*(3*(1−νs2))12

[0015] E s and ν sthe elastic modulus or Poisson's ratio of the shell material. The previous expression specifies an upper limit for the pressure to which the hollow microspheres can be subjected. In general, thin-walled microspheres can withstand very large buckling loads. However, it has been shown that, in contrast to calculations, experimental investigations for hollow microspheres are more reliable for determining the buckling pressure. The maximum theoretical packing density of monodisperse spheres is 74%, either in cubic closest packing or hexagonal closest packing. However, this highly ordered arrangement is not achieved in practice, and a maximum random packing of approximately 64% is more realistic. A higher packing density can be achieved when using polydisperse spheres with a specific grading curve. However, the grading curve interval is very limited.Table 1 below shows examples of possible hollow microsphere designs based on the above formulas. The following boundary conditions are given as examples. The tensile strength is set at 4890 MPa, corresponding to commercially available S2 glass types, and the wall thickness of the hollow microsphere is set at 8 µm, based on the tests listed below. The density of the shell matrix of the hollow microspheres is set at 2.5 g / cm³. 3because the inclusion of iron particles at approximately 1-4% has only a minor impact on the density. The table shows the ratios in comparison to gasoline, with gasoline having an energy content of 12 kWh / kg and 8.9 kWh / l. The inventive incorporation of metal particles into the hollow microsphere wall usually leads to a weakening of their tensile strength. The table shows the weakening factor that would be possible to still maintain the safety factor of 1.5. If the safety factor is insignificant, i.e. 1, the values ​​highlighted in gray can be achieved. If factors greater than 1 are possible according to publication DS49, corresponding improvements result.

[0016] The invention is based on the object of providing a storage system for the storage and transport of hydrogen using reversible hydrogen storage elements based on hollow microspheres, which exhibit a higher gravimetric storage density than the prior art. Higher internal pressures should be possible by only slightly reducing the tensile strength of the hollow microsphere walls during the loading and unloading process. Furthermore, the loading and unloading temperatures should be kept lower than currently possible. Heating of the hollow microspheres should occur intrinsically and require no additional chemicals.

[0017] The problem solved according to claim 1 was solved by the use of a storage system according to the invention for the storage and transport of hydrogen with hollow microspheres, which is characterized in that metal, metal alloy, or metal composite particles, or mixtures thereof, which can be inductively heated, are embedded in the closed shells of the hollow microspheres. Hydrogen permeation through the hollow microsphere walls should only occur to a subordinate extent through the basic component, usually glass, of the sphere wall. Rather, inductive heating of the embedded metal particles greatly increases their permeability, so that hydrogen transport occurs preferentially through these metal particles. To ensure almost homogeneous inductive heating of the hollow microsphere bed in an alternating electric field of a coil arrangement, a Helmholz coil arrangement is particularly suitable.Maxwell coils, Braunbek coils, or Barker coils can also be used. The metal particles are heated rapidly, which increases their hydrogen permeability very rapidly by several orders of magnitude, while heat transfer to the remaining shell material occurs slowly due to its poorer thermal conductivity. This eliminates the need to heat the hollow microspheres to the high temperatures required by current technology. This allows the temperature level to be kept lower during loading and unloading, significantly reducing the energy required for heating. The use of intrinsic heating through inductive heating has the further advantage, in contrast to external heating, that the heat transfer coefficient, which is naturally very low for these hollow microspheres, is more or less irrelevant.The tensile strength of the shell material is only slightly reduced, particularly during the discharge step, due to the lower temperature level, making higher internal pressures feasible. In addition to the frequently used glass as the base material for hollow microspheres, ceramic, polymer, metal, carbon, or composite hollow spheres, or mixtures thereof, can also be used. If hollow metal spheres are used, care must be taken to embed ferromagnetic particles in non-ferromagnetic base material so that they can be heated separately by induction. In principle, multi-shell designs can be used in addition to single-shell designs to increase strength and minimize the tendency to fracture during handling and transport. The protective shell must be almost completely permeable to diffusion or slightly permeable to hydrogen.The metal, metal alloy, or metal composite particles can be composed of ferromagnetic or non-ferromagnetic metals according to claim 3. If non-ferromagnetic particles are used according to claim 8, the induction must be carried out with low-frequency alternating fields. However, this has the somewhat unfortunate disadvantage of increasing energy losses in the excitation coil(s). A more suitable method for induction heating is the use of ferromagnetic materials such as iron, nickel, or cobalt, or their alloys. Higher-frequency excitation is typically used here, which has a significantly better energy balance. Combinations of both metal types are particularly suitable, with the heating process being particularly well-managed by the ferromagnetic component, and a suitable non-ferromagnetic partner particularly well-supporting hydrogen permeation.A combination of iron or nickel with palladium or its alloys, which are particularly good at transporting hydrogen, represents a good solution. Since hydrogen transport can occur with palladium and its alloys even at room temperature, to a small but not negligible extent, it is important to ensure that their layer thicknesses are not excessive. These should also be limited to the smallest possible layer thickness for cost reasons. To enable good hydrogen exchange between the outer and inner regions, or vice versa, the individual particles should extend somewhat into the inner region as well as slightly into the outer region of the spheres. Therefore, a particle size slightly larger than the wall thickness of the hollow microspheres is particularly suitable.To achieve a favorable ratio of the free spherical cap surfaces to the sphere diameter, the outer diameter of the hollow spheres should have a ratio of 1 to 0.71 to 0.88 to the wall thickness of the shell. Since the particles thus completely penetrate the shell wall, it is essential, according to claim 3, that they are embedded in the hollow microsphere walls without cracks or gaps. To ensure that the boundary area between the shell matrix and the metal intercalation particles is free of cracks or gaps, the metal particles according to claim 6 can be provided with an additional adhesion-promoting layer to ensure a particularly good bond with the base shell material. This additional layer must enter into very good chemical and physical interactions with the metal surface and, at the same time, interact very well with the silicate properties of glass. Silane-containing or silicic acid ester-containing adhesion promoters are suitable for this purpose.They are applied to the particle surface in a thin layer using a sol-gel process. This intermediate layer also has the task of cushioning stress differences between the induction-heated metal particles and the cooler glass matrix during the heating process. This task can be accomplished particularly well using semi-pyrolyzed silane-silicon dioxide or semi-pyrolyzed silicic acid ester-silicon dioxide intermediates. Similar results can also be achieved through the partial pyrolysis of organic titanates, titanium chelates, or organic zirconates. Partial pyrolysis of these intermediate layers leads to a glass-like structure of the layer and is particularly well suited to ensuring crack-free properties even under thermal stress. The use of partially hydrolyzed oligomeric silanes and silicic acid esters, or mixtures thereof, in particular, leads to this particularly suitable glass-like state of the intermediate layer.In order not to destroy the semi-amorphous state of this layer during the sintering process when producing the mixed glass / metal particles, it is important to ensure that the layer itself is very thin. A very thin layer is also particularly important because it is also present on the surface of the metal particles towards the gas region and can somewhat hinder gas exchange. To ensure that this hindering layer does not reduce hydrogen transport too much, it must be made thin enough. A further advantage, particularly when using oxidation-sensitive metal particles, is that additional oxidation protection is provided during the production of the hollow microspheres using the spray pyrolysis process. The use of a thin palladium layer around the iron core of the metal particles to be incorporated is also particularly important for this oxidation protection, in addition to supporting hydrogen permeation. Fig.Figure 3 shows the basic structure of a hollow microsphere according to the invention. The majority of the following explanatory figures are only schematic and symbolic and not to scale or size. They serve to illustrate and explain the basic principles of the components and devices according to the invention, whereby any modifications that lead to similar results are not excluded and are included according to the invention. Figure 1 represents the entire hollow microsphere. It consists of the shell 2 consisting of the shell base material 3, which surrounds the interior space 4 that absorbs the hydrogen. Depending on the design, a varying number of metal-containing particles 5 are embedded in the shell. These particles exhibit a certain size variation 6a and 6b.In the optimal case, the particles penetrate the wall completely, so that each spherical cap 7a extends into the interior 4 and the opposite spherical cap 7b extends into the exterior 8. A small proportion of the particles 5 do not completely penetrate the shell 2, but are, accordingly, 9a more facing the interior 4 or 9b more facing the exterior 8. The number of these suboptimally stored particles within the shell can be reduced to a minimum by single or repeated use of the VTF process described in the example below. With a small coverage 10a or 10b of the spherical cap by the shell base material, hydrogen transport at high temperatures is hindered but not completely prevented.The metal, metal alloy, or metal composite particles 5 according to claim 4 are characterized by the fact that their hydrogen permeability is very low at moderate temperatures such as room temperature and increases several times over when the temperature is increased by several hundred degrees Celsius, preferably by 2 to more than 4 orders of magnitude. The use of metal composite particles 11 according to claim 5, which are designed in the form of a core-shell structure or a multilayer structure, has proven particularly successful. The core 12 or the core layers are made of ferromagnetic material, and the shell or the edge layers are made of oxidatively stable materials. The intermediate layer 13 between the adhesion-promoting layer 14 and the core 12 should have particularly good hydrogen permeability at elevated temperatures; palladium or even less noble elements such as titanium, niobium, vanadium, and tantalum can be used.Although palladium is expensive, it has the great advantage that it can be easily electroplated onto the core structure of the metal particles without external current. The ferromagnetic core of the particles according to claim 9 can consist of iron, in particular carbonyl iron, nickel, cobalt, and a variety of their alloys, in particular nickel-phosphorus alloys, Heusler alloys, and also non-metallic materials such as chromium dioxide, manganese arsenide, and europium(II) oxide. It is important to ensure that the temperatures during loading and unloading do not exceed the respective Curie temperature of the material used. If the Curie temperature is exceeded during the sintering process for obtaining the glass / iron composite material or during the spray pyrolysis process for hollow microsphere production, additional post-magnetization of the hollow spheres is recommended before their use.Although nickel-phosphorus alloys have a relatively low Curie temperature, they can still represent a good alternative to carbonyl iron. They can be easily produced by bath decomposition of commercially available electroless nickel baths. This is achieved by raising the temperature above the intended operating temperature and by increasing the pH of the bath, initiating spontaneous decomposition of the bath. After a short time, particle growth is stopped by quenching in an ice bath (directly pouring it into the bath). The resulting particles are characterized by excellent particle diameter uniformity. Due to the brittleness of glass, the glass-based hollow microspheres are somewhat susceptible to breakage due to mechanical stress during transfer and handling processes.Therefore, the storage system according to claim 7 can be designed such that a larger quantity of hollow microspheres can be combined into easily handled, fully gas-permeable enclosures for easy local relocation, for example, by pumping or batch relocation, and in particular, for further protection against mechanical stress during these relocation processes. According to claim 10, the invention relates not only to hollow microspheres; rather, the storage system can also be characterized in that closed microtubes or mixed-pore, i.e., closed-pore, and open-pore microfoams are used instead of hollow microspheres. This embodiment has the advantage that they can potentially be manufactured more cost-effectively, but has the disadvantage that the corresponding bursting pressure in the case of microtubes is only half as high as that of microspheres.However, a better packing density is achievable with microtubes. In contrast, microfoams exhibit the lowest packing density of the three systems.

[0018] The invention will be described in more detail using an example: 1.) Production of the metal particles to be stored. 50g of carbonyl iron powder from PMCtec GmbH Braunfels, type HYK, with a particle size distribution of D10 = 4µm; D50 = 8µm; D90 = 18µm, is intensively dispersed for 20 minutes (3000 rpm) in 100 ml of a mixture of 20% water and 78% ethanol thickened with 2% METHOCEL™ A4C (viscosity approx. 400 cP). This mixture is quickly added to 1 liter of water in an ultrasonic bath and stirred for 5 minutes. 20 ml of concentrated hydrochloric acid is added to the mixture while stirring to activate it, and then the particles are separated as quickly as possible using a magnetic collector (MAGNET BAR SEPARATOR from Magnetar Vismagneten). The collected iron particles are immediately transferred, while stirring, to the following electroless palladium bath. The bath had the following composition: 2 g / L PdCl2 2H2O, 27 g / L NH4Cl, 10 g / L NaH2PO2 2H2O, and 160 ml / L NH4OH (28%). The deposition temperature was 50°C and the stirring was continuous. The deposition time varied between 5 and 20 minutes.To complete the deposition process, stirring is interrupted, and the particles are removed with the magnetic collector. The nearly clear electrolyte is poured off while cooling, and the collected particles, including the remaining electrolyte, are transferred to ice water with a pH of 10 (NaOH) and briefly stirred. They are then collected again, rinsed again with deionized water, and finally reunited with the magnetic collector. The palladium-coated iron particles are added, while still wet, to a mixture consisting of 10% of a hydrolyzate of 3-glycidyloxypropyltrimethoxysilane (Dynasylan HYDROSIL 2926 from Evonik), 10% lithium polysilicate solution, and 10% colloidal silicon dioxide LUDOX AS-30, both from Grace, with the remainder deionized water, and stirred for 10 minutes. Then collected again and freed from most of the liquid by gentle centrifugation. In . Fig.4a shows the metal particles as an example. The still-moist particle mixture is immediately intensively mixed with varying amounts of the subsequent glass powder. Forced drying takes place at approximately 120°C while continuously mixing. 2.) Production of the glass powder. 1000g of S2 glass from AGY Holding Corp. was pre-crushed and placed in a planetary ball mill (Retsch PM100 from RETSCH GmbH). Approximately 220 ml of the pre-crushed glass material was combined with approximately 150 ml of zirconium oxide grinding balls (approx. HV 1200, diameter 30 mm) from Retsch. At a speed of 500 rpm, the material was comminuted to an average particle size of approximately 100 to 3000 µm. The powder was then separated from fine particles (<150 µm) and large particles (>250 µm) in a Retsch AS 200 jet air jet sieve. Fig. 4b is an example of the glass powder before sieving and in Fig. 4c shown after sieving. 3.) Production of the metal / glass composite powder. The dried metal particle / glass powder mixture is converted into the metal / glass composite powder following the procedure described in publication DS46. The production process involved the following steps: First, the well-homogenized metal particle / glass powder mixture is highly compacted by cold pressing with a hydraulic press. The specific pressure during cold pressing was approximately 3.8 kN / cm. 2. Sintering then takes place in a protective, reducing hydrogen atmosphere at a temperature of approximately 500 to 1000°C for 60 minutes, depending on the test series. After cooling, further cold plastic deformation is carried out on a hydraulic press to obtain a less porous material. The resulting porosity is between 5 and 10%. The metal / glass composite monolith is first coarsely divided and then crushed in a laboratory jaw crusher (JAW BREAKER BB 50 from Retsch GmbH) to a grain size of approximately 2-3 mm. This coarse grain is then crushed in the aforementioned planetary ball mill under the aforementioned conditions to a powder with an average particle size of 150 to 250 µm. The fine and coarse grains are separated according to the glass powder. Fig. Figure 4d shows a freeze fracture of the obtained metal / glass composite powder. 4.) Production of the metal / glass hollow microspheres. The microspheres were produced using the flame spheroidization method. For this purpose, the metal / glass composite powder is sprayed into an MK74 oxygen / acetylene flame spray gun from Metallisation Ltd. (Kymera International) with an oxygen / acetylene ratio of 1:1 and a gas flow rate of approximately 2 m 3 / hour per gas type, was injected. The solids feed was between 1.2 and 4.0 kg / hour. To quickly cool the hollow spheres emerging from the flame cone, extremely cooled air (approx. -20°C) was used in countercurrent. The spheres were collected in cooled (approx. 5°C) metal collecting trays. Due to their size, the conversion of the powder to microspheres does not occur 100% in a single step, resulting in almost ideal spheres. Instead, a small amount of unreacted powder remains and a large number of the hollow bodies do not have a good spherical shape, as described in document DS30. To improve the quality of the hollow microsphere production, the spheres are subjected to one or more VTS processes in a second step, depending on their size and metal particle content. The VTF process is carried out by setting up a vertical flame as the heat source in a quartz tube with a diameter of 3 cm and a length of 50 cm.A Bunsen burner is attached to the lower end of the tube. The propane and air flow is adjusted to create a blue flame with a constant height of approximately 6-8 cm. The initially produced hollow microsphere mixture is then fed into the quartz tube through the upper opening. The particles are collected in a collecting funnel at the lower end and cooled. The collected spheres are then subjected to an acid wash step in which they are gently stirred in 5 molar acetic acid for 2 minutes, followed by washing with deionized water for 5 minutes and then dried at 80°C. To relieve any stresses that arise, particularly at the glass / metal interface, and to position the metal particles as centrally as possible within the shell of the hollow microspheres, the hollow microspheres were subjected to a 24-hour relaxation by inductive heating (see below) of the metal particles. Fig.5a shows an example of hollow glass microspheres without embedded metal particles in Fig. Figure 5b shows the hollow spheres with incorporated metal particles. 5.) Separation of suitable hollow microspheres from unsuitable hollow spheres and other interfering contaminants. The production of hollow microspheres is a multi-stage process, with a certain amount of unsuitable product components being formed at each process step. To avoid individual separation or purification steps, a single qualifying separation step is carried out after completion of production. For this purpose, the total amount of hollow microsphere conglomerate is loaded to a level that will be relevant in the subsequent application (see below). To be on the safe side, the load is increased by 10%. After the load cycle, a separation is carried out in a sink-float treatment in water or a heavy liquid, e.g., a sodium polytungstate solution.Insufficiently expanded metal / glass particles, hollow spheres with excessively thin walls and crushed hollow spheres, hollow spheres that cannot withstand high pressure, and other residual particles are significantly heavier than optimally or suitably manufactured hollow microspheres due to their lower density at atmospheric pressure. Depending on the design, the density of the hollow microspheres in these tests ranges between approximately 0.3 g / cm³. 3 (e.g. sphere radius 200µm; wall thickness 8µm) and approx. 1.22 g / cm 3 (e.g., sphere radius 100µm; wall thickness 20µm). The density of this example, which is the best design to date with an average sphere radius of approximately 160µm and a wall thickness of approximately 8µm, is approximately 0.36 g / cm 3 . Thus, in this example, water, with a density of approximately 2.5 g / cm 3The sink-float separation can be carried out very effectively with respect to the interfering particles to be separated. It should be noted at this point that a small proportion of interfering particles can be easily tolerated in the system according to the invention. In the present example, the finally determined interfering particle proportion is approximately 15 to 20 wt.%, depending on the test series. 6.) Filling the hollow microspheres with hydrogen. A specially developed apparatus was designed and built for the loading and unloading tests. Fig.Figure 6 shows an overview of the test facility 15. The core of the facility is an aluminum oxide-based ceramic cladding tube 16 with an outer diameter of 105 mm and an inner diameter of 90 mm and a length of 130 mm, of the DEGUSSIT AL23 brand from KYOCERA Fineceramics Europe GmbH. The ends of the tube are terminated with round ceramic sections 17 made of tube bars made of oxide ceramic of the F99.7 brand from the DEGUSSIT AL23 brand with a diameter of 90 mm and a thickness of 30 mm. These terminations have several openings and through-holes 18. The terminations are only loosely inserted for easy removal. A Helmholtz coil arrangement 19a and 19b, with a coil spacing of 52 mm, is attached to the center of the ceramic tube. A non-ferromagnetic thermocouple 20 is inserted into the center of the arrangement.This assembly is housed in a high-pressure-resistant double flange assembly 21, specially manufactured from an aluminum tube with the alloy composition "EN AW 6082 AlSi1 MgMn" with an outer diameter of 200 mm, an inner diameter of 120 mm, and a height of 140 mm. The flange rings and flange covers, made of the same material, have an outer diameter of 280 mm and a thickness of 50 mm; both materials were purchased from Westdeutscher Metall-Handel GmbH. The flange tube and the flange rings were fully force-welded. 2 mm thick PTFE sealing rings from RESOGOO GmbH & Co. KG were used as seals. Ten non-magnetic M12 stainless steel screws with a strength class of 10.9 were attached to the head and base flanges, and ten additional screws were attached continuously from the outside of the upper cover to the outside of the lower cover.The high-pressure hydrogen gas supply 22 with shut-off valve 23 and a vacuum purge connection 24 with shut-off valve 25 are attached to the underside. A T-piece 28 is attached there to vent the system. The required high gas pressure was provided by a two-stage gas compressor of the "MAXIMATOR DLE 15-75-2 H" brand from MAXIMATOR GmbH. The thermocouple feedthrough 26 is provided by a Spectite feedthrough from the MF series from TC Mess- und Regeltechnik GmbH. A digital manometer LABDMM2 2000 bar 27 from VETEK WEIGHING AB is also attached for pressure determination. For safety reasons, a hat-shaped high-pressure bursting disc 29 with a burst pressure of up to 1300 bar, from Wehberg Safety GmbH, is attached via a conical sealing seat to meet the extreme sealing requirements. The ceramic container is filled with the cabbage balls and inserted into the pressure vessel and completely sealed.The entire device is evacuated twice and flushed with hydrogen. The filling of the hollow spheres up to a filling pressure of approximately 1000 bar takes place in several steps. First, the metal particles are heated using induction coils until the thermocouple indicates an average temperature of approximately 60°C. A filling pressure of approximately 200 bar is then applied. The temperature is then increased by 10°C and the pressure by 200 bar in four further steps. Finally, the temperature is adjusted to 120°C using PID control, and the final loading is carried out at 1000 bar for 15 minutes. After loading, the induction heating is switched off and the device is cooled to room temperature. The excess pressure is then reduced to atmospheric pressure. The device is briefly evacuated and then vented. The filled hollow spheres are then removed and subjected to the sink-float treatment described in point 5. They are then stored for various lengths of time. 7.) Emptying the hydrogen-filled hollow microspheres. The hollow microspheres combined from several production cycles are separated into several size fractions by sieving after sink-float processing. An upper and lower sieve are used for each fraction. Table 2 summarizes the average sphere diameters and the mesh counts of the upper and lower sieves used. Table 2 fraction average ball diameterµm upper mesh size lower mesh size 1 460 35 40 2 390 40 45 3 320 45 50 4 275 50 60 5 230 60 70 6 165 70 100

[0019] The ceramic core of the above-mentioned apparatus is sealed at the bottom with the bottom cap, the thermocouple inserted in the center, and then completely filled with one fraction of hollow microspheres each. Packed as tightly as possible by shaking, the thermocouple is then sealed with the top cap. The apparatus is then placed in the pressure housing and filled with 1 mm solid glass spheres to keep the remaining dead volume as small as possible. The entire chamber is sealed pressure-tight and airtight and evacuated. A defined compensation volume (0.5 l) is then connected to the T-piece of the evacuation access and partially vented internally. The remaining dead volume is determined from the resulting pressure increase, as this can vary widely between different experiments. The apparatus is then completely evacuated again, and the gas escape from the hollow microspheres is initiated by inductive heating of the metal particles.The temporal progression of the gas pressure increase in relation to the average internal temperature of the different hollow microsphere fractions was determined. The variation parameters tested in numerous test series included average sphere size, wall thickness, metal particle content, palladium layer thickness, average degassing temperature, and gas filling pressure. After the test series was completed, the volume of the hollow sphere fraction used was determined. In a subsequent sink-float processing, the destruction rate of the microspheres was determined again, which was always well below 1%. 8.) Example result of a hollow microsphere variant This hollow microsphere variant had an average sphere diameter of approximately 320 µm, a wall thickness of approximately 8 µm, a surface metal particle content of approximately 1%, corresponding to approximately 4 wt.%, a palladium layer thickness of approximately 0.7 µm, and average degassing temperatures of up to 120°C using PID control at a gas filling pressure of approximately 1000 bar. Under these conditions, a calculated hydrogen content of approximately 12 wt.% was obtained. The degassing measurements were carried out for 30 minutes each. Table 3 summarizes the measured values ​​for the mean final temperature, the determined hollow microsphere volume, the calculated mean internal volume (total volume of the microspheres) - (assumed volume of the sphere shell at 320 µm and wall thickness of 8 µm), the measured dead volume including 500 cm 3 Compensation volume, the measured pressure after 30 minutes and the calculated final pressure assuming complete pressure equalization. Table 3 Final temperature °C Micro hollow sphere volume cm 3 Hollow sphere internal volume cm 3 measured dead volume cm 3 measured final pressure (30 min) bar calculated final pressure Mean pressure / calculated pressure% 60 272 233 850 35 199 17,6 80 266 228 885 93 195 47,7 100 280 240 863 192 213 90,0 120 268 230 890 199 205 97,0

[0020] Fig. 7a bis Fig.Figure 7d shows an example of the pressure curve over time in this series of measurements. The dashed horizontal line shows the respective possible final values ​​at complete pressure equalization. It should be noted that the measurement error is approximately ± 5%. Furthermore, it is clear that the temperatures in the metal particles are significantly higher than the stated average operating or final temperature due to their small proportion. This explains the rapid permeation behavior even at moderate temperatures. The hollow microspheres used in this experiment were then filled again with hydrogen at approximately 1000 bar and stored at room temperature for 50 days, and the weight loss was determined. The weight loss was determined to be 0.0161 g, which corresponds to a hydrogen loss of approximately 0.14%. This is a typical example.The individual storage, loading, unloading, and storage behavior can be significantly modified by the sphere size, wall thickness, tensile strength of the glass matrix, the proportion of metal particles, and the thickness of the palladium layer on the metal particles, and can be optimized for a wide range of applications. List of non-patent literature DS1 LUO Yuan, LIU Qiang, WANG Yuanxin, LIAO Bin, YAN Kaiqi, ZHANG Jingjie. Recent development of hydrogen storage in hollow glass microspheres. Journal of Functional Materials. 2023, 54(6): 6011-6020 doi.org / 10.3969 / j.issn.1001-9731.2023.06.002 DS2 MUKESH KUMAR SHUKLA. A Comprehensive Review on Hollow Microspheres Gastroretentive Drug Delivery System. 2022| IJIRT | Volume 9 Issue 6 | ISSN: 2349-6002 DS3 Jesindha Beyatricks, S.Kavimani, M.K. Mohan Maruga Raja, K. Selva Kumar. Recent trends in microsphere drug delivery system and its therapeutic applications -A Review. Crit. Rev. Pharm. Sci, 2(1):1-14, 2013. DS4 Ditmire, T., Roth, M., Patel, P.K. et al. Focused Energy, A New Approach Towards Inertial Fusion Energy. J Fusion Energ 42, 27 (2023). doi.org / 10.1007 / s10894-023-00363-x DS5 Pilon, L.: Hydrogen storage in hollow microspheres. In: Sherif, S.A., et al. (Hrsg.) Handbook of Hydrogen Energy, Kap. 25, S. 764-806. CRC Press, Boca Raton, USA (2014) DS6 C.D. Hendricks; A. Rosencwaig; R.L. Woerner; J.C. Koo; J.L. Dressler; J.W. Sherohman; S.L. Weinland; M. Jeffries (1979). Fabrication of glass sphere laser fusion targets. , 85-86(part-P1), 107-111. doi:10.1016 / 0022-3115(79)90476-8 DS7 C.D. Hendricks (1979). Fuel pellets and optical systems for inertially confined fusion. , 85-86(part-P1), 79-86. doi:10.1016 / 0022-3115(79)90472-0 DS8 E.V Sokol; N.V Maksimova; N.I Volkova; E.N Nigmatulina; A.E Frenkel (2000). Hollow silicate microspheres from fly ashes of the Chelyabinsk brown coals (South Urals, Russia). , 67(1), 35-52. doi:10.1016 / s0378-3820(00)00084-9 DS9 C.D. Hendricks, Glass spheres, in Materials Handbook, Ceramics and Glasses, Vol. 4, S.J.Schneider Jr., ed. ASM International, Materials Park, OH. DS10 Ding, J.Y., Day, D.E. Preparation of silica glass microspheres by sol-gel processing. Journal of Materials Research 6, 168-174 (1991). doi.org / 10.1557 / JMR.1991.0168 DS11 Jang, K. Y., K. Kim, R. S. Upadhye (1990). Study of sol-gel processing for fabrication of hollow silica-aerogel spheres. Journal of Vacuum Science & Technology A: Vacuum, Surfaces, and Films, 8(3), 1732-1735. doi:10.1116 / 1.576839 DS12 Kim, Kyekyoon (Kevin) (1994). Fabrication of Glass Micro- and Nanospheres from Liquid Precursors Using Droplet Generation and Sol-Gel Processing. MRS Proceedings, 372(), 25-32. doi:10.1557 / proc-372-25 DS13 J. Bertling; J. Blömer; R. Kümmel (2004). Hollow Microsperes., 27(8), 829-837. doi:10.1002 / ceat.200406138 DS14 Alagusundaram M, Chetty MSC, Umashankari K, Umashankari.K, Attuluri Venkata Badarinath, Lavanya.C, Ramkanth.S., Microspheres as a novel drug delivery sysytem - a review. Int J ChemTech Res. 2009;1(3):526-534. DS15 Nirav R. Patel, Dhagash A. Patel, Praful D. Bharadia, Vikram Pandya, Darshan Modi. Microsphere as a novel drug delivery. Int. J. of Pharm. & Life Sci. (IJPLS), Vol. 2, Issue 8: Aug.: 2011, 992-997. DS16 Bansal, H. Kaur, S., Gupta, A.K.. (2011). Microsphere: Methods of prepration and applications; A comparative study. International Journal of Pharmaceutical Sciences Review and Research. 10. 69-78. DS17 Chaudhari, A., Jadhav, Kisan, Kadam, V.J.. (2010). An over view: Microspheres as a nasal drug delivery system. International Journal of Pharmaceutical Sciences Review and Research. 5. 8-17. DS18 Manish Jamini, Saurabh Rawat. REVIEW ARTICLE A Review on Microsphere Manish Jamini, Saurabh Rawat. A Review on Microsphere Research Journal of Pharmaceutical, Biological and Chemical Science (2013) Volume 4 Issue 1. 1227-1233. ISSN: 0975-8585. DS19 Smita.P. Borkar, S.G. Jawale, P. M. Deshmukhe, Ijppr.Human, 2021; Vol. 22 (4): 41-60. DS20 loan Bica. Formation of glass microspheres with rotating electrical arc. Materials Science and Engineering: B, 77, (2), (2000) 210-212, ISSN 0921-5107. doi.org / 10.1016 / S0921-5107(00)00483-9. DS21 J. A. Lewis; W. H. Gauvin (1973). Motion of particles entrained in a plasma jet. 19(5), 982-990. doi:10.1002 / aic.690190515 DS22 loan Bica (2002). Iron micro-spheres generation in argon plasma jet. 2002Materials Science and Engineering B. 88(1), 107-109. doi:10.1016 / s0921-5107(01)00830-3 DS23 Qihan Meng; Lei Wang; Fei Chen; Qingfei Hao; Xudong Sun. Preparation of Ramsdellite-type Li 2 Ti 3 O 7 hollow microspheres with high tap density by flame melting method as anode of Li-ion battery. Research Bulletin, ISSN: 0025-5408, Vol: 161, (2023) 1121662023 doi:10.1016 / j.materresbull.2023.112166 DS24 Teitel, Robert J. 1981. Microcavity Hydrogen Storage - Final Progress Report, Technical. Report BNL 51439, New York, Brookhaven Nation Laboratory DS25 Teitel, T.M. Henderson, and J.E. Luderer, „Microcavity Systems for Automobile Applications,“ Proceedings of the U.S. Department of Energy Chemical / Hydrogen Energy Systems Cntractor Review, CONF 781142, Nov 27-30, 1978, p.289. DS26 Teitel , T. M. Henderson , J. E. Luderer , and J. Powers , Microcavity . for Automotive Applications. Brookhaven National Laboratory. Nov. 1978. DS27 Woerner, R. L., Weinstein, B. W., Moen, I. M., and Rittman, J. G. 1979. Working Strengths and D-T Fill Procedures for Glass Microsphere Laser Fusion Targets, Technical Report UCRL-82728, Livermore, CA, Lawrence National Laboratory. DS28 M. Keding, M. Tajmar, P. Dudzinski, A. Reissner. Development of Innovative Hydrogen and Micro Energy Solutions at the Austrian Research Centers. 6th International Energy Conversion Engineering Conference (IECEC) 28 - 30 July 2008, Cleveland, Ohio. AIAA 2008-5643. doi:10.2514 / 6.2008-5643 DS29 M. Keding, A. Reissner, G. Schmid, M. Tajmar. Innovative Hydrogen Storage Solutions for Aerospace Applications. 18th World Hydrogen Energy Conference 2010 - WHEC 2010. Schriften des Forschungszentrums Jülich / Energy & Environment, Vol. 78-5 Institute of Energy Research - Fuel Cells (IEF-3). ISBN: 978-3-89336-655-2 DS30 Lee, May Yan; Tan, Jully; Heng, Jerry YY; Cheeseman, Christopher (2017). A Comparative Study of Production of Glass Microspheres by using Thermal Process. IOP Conference Series: Materials Science and Engineering, 205, 012022. doi:10.1088 / 1757-899X / 205 / 1 / 012022 DS31 Sridhar Dalai, ; Vijayalakshmi, Savithri; Pratibha Sharma, (2013). Preparation of Hollow Glass Microspheres (HGMs) from Amber Coloured and Borosilicate Glass Frits. Advanced Materials Research, 678, 37-41. doi:10.4028 / www.scientific.net / AMR.678.37 DS32 Gupta, Dhanak; Hossain, Kazi M. Zakir; Ahmed, Ifty; Sottile, Virginie; Grant, David M. (2018). Flame spheroidized phosphate-based glass particles with improved characteristics for applications in mesenchymal stem cell culture therapy and tissue engineering. ACS Applied Materials & Interfaces, acsami.8b05267. doi:10.1021 / acsami.8b05267 DS33 Yamanishi, YT Tanabe S. Imoto. “Hydrogen Permeation and Diffusion through Pure Fe, Pure Ni and Fe-Ni Alloys.” Materials Transactions JIM 24 (1983): 49-58. doi:10.2320 / matertrans1960.24.49 DS34 Christian Schäfer, Diffusion properties of certain metals in high-temperature hydrogen separation. Dissertation, Technical University of Munich (2010). DS34a Fischer, W. (1967). On the kinetics of hydrogen permeation through nickel. Journal of Natural Science A, 22(10), 1581–1586. doi:10.1515 / zna-1967-1020 DS35 Santucci, A., S. Tosti, A. Basile, (2013). Handbook of Membrane Reactors; Alternatives to palladium in membranes for hydrogen separation: nickel, niobium and vanadium alloys, ceramic supports for metal alloys and porous glass membranes., 183-217. doi:10.1533 / 9780857097330.1.183 DS36 Yukawa, H., Nambu, T, Y. Matsumoto, Y., (2014). Advances in Hydrogen Production, Storage and Distribution; Design of group 5 metal-based alloy membranes with high hydrogen permeability and strong resistance to hydrogen embrittlement., 341-367. doi:10.1533 / 9780857097736.3.341 DS37 Johnson, E.W., Hill, M.L., The Diffusivity of Hydrogen in Alpha Iron, (1960) Trans. Met. Soc., AIME 218, 1104-1112. DS38 Suzuki, Asuka; Yükawa, Hiroshi (2020). A Review for Consistent Analysis of Hydrogen Permeability through Dense Metallic Membranes. Membranes, 10(6), 120. doi:1 0.3390 / membranes10060120 DS39 Steward, S.A. Review of hydrogen isotope permeability through materials, report, August 15, 1983; [Livermore,] California. (https: / / digital.library.unt.edu / ark: / 67531 / metadc1066698 / : accessed March 25, 2024), University of North Texas Libraries, UNT Digital Library, https: / / digital.library.unt.edu; crediting UNT Libraries Government Documents Department. DS40 S-2 Glass® High Performance Fiber, Solutions for Demanding Applications Product Invormation, AGY Aiken LCC, 2022. DS41 MADHUMITA GOSWAMI, T. MIRZA, A. SARKAR, SHOBHA MANIKANDAN, SANGEETA, S. L. VERMA, K. R. GURUMURTHY, V. K. SHRIKHANDE, G. P. KOTHIYAL, Preparation and characterization of magnesium-aluminium-silicate glass ceramics. Bull. Mater. Sci., 23, (5), 2000, 377-382. doi:10.1007 / BF02708387 DS42 J. Nixdorf. Die Faserverstärkung von Aluminium. Materialwissenschaft und Werkstofftechnik (1974), 5(2), 84-95. doi:10.1002 / mawe.19740050208 DS43 Kainer KU, Bergmann HW, Mordike BL. Powder Metallurgically Produced Metal-Glass Composites. Powder Metallurgy. 1984;27(1):30-38. doi:10.1179 / pom.1984.27.1.30 DS44 Bergmann, Hans-Wilhelm, Philippi, Georg, Wassermann, Günter. "Structure and mechanical properties of highly deformed aluminum-glass fiber composites." International Journal of Materials Research, vol. 70, no. 12, (1979), 802-807. doi.org / 10.1515 / ijmr-1979-701209 DS45 G. Tontini, LL Evangelista, AI Ramos Filho, RA Elias, G. Hammes, NJ Batistela, C. Binder, AN Klein, V. Drago. Study of soft magnetic composites of iron coated with nanoparticles dispersion in liquid glass. Journal of Magnetism and Magnetic Materials, Vol. 487, (2019), 165351, ISSN 0304-8853. doi.org / 10.1016 / j.jmmm.2019.165351 DS46 Getmanovskiy, Yuriy & Maltsev, Ilya. (2024). Investigation of the heat resistance of a metal-glass composite material based on iron. doi:10.21203 / rs.3.rs-3927503 / v1. DS47 Wei Ding, Longtao Jiang, Yaqin Liao, Jiabin Song, Bingqing Li, Gaohui Wu. Effect of iron particle size and volume fraction on the magnetic properties of Fe / silicate glass soft magnetic composites. Journal of Magnetism and Magnetic Materials, Vol. 378, (2015), 232-238, ISSN 0304-8853. doi.org / 10.1016 / j.jmmm.2014.09.019. DS48 Yang, Bai; Wu, Zhangben; Zou, Zhiyu; Yu, Ronghai (2010). High-performance Fe / SiO2 soft magnetic composites for low-loss and high-power applications. Journal of Physics D: Applied Physics, 43(36), 365003. doi:10.1088 / 0022-3727 / 43 / 36 / 365003 DS49 Bergmann, Hans W., Frommeyer, Georg. „Gefüge und Eigenschaften von Verbundwerkstoffen des Dreistoffsystems Eisen-Kupfer-Glas / Microstructure and Properties of Composites of the Ternary Iron-Copper-Glass System“ International Journal of Materials Research, vol. 68, no. 9, (1977) 590-594. doi.org / 10.1515 / ijmr-1977-680903 DS50 Rambach, G.D. Hydrogen transport and storage in engineered glass microspheres, article, April 18, 1995; California. (https: / / digital.library.unt.edu / ark: / 67531 / metadc792168 / : accessed March 25, 2024), University of North Texas Libraries, UNT Digital Library, https: / / digital.library.unt.edu; crediting UNT Libraries Government Documents Department. IL1 https: / / www.chemietechnik.de / anlagentechnik / thermische-verfahren / scale-up-der-ultraschall-spruehpyrolyse-zur-herstellung-von-nanopulver.html IL2 https: / / de.wikipedia.org / wiki / Haftvermittler IL3 https: / / en.wikipedia.org / wiki / Strength_of_glass IL4 https: / / www.r-g.de / wiki / Glasfasern ZITATE ENTHALTEN IN DER BESCHREIBUNG

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[0000] US 2676892A

[0003] US 2978339A

[0003] US 3838998A

[0003] US 4661137A

[0003] US 6254981B1

[0003] DE 102016208141A1

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[0010] Cited non-patent literature

[0000] Christian Schäfer, Diffusion properties of certain metals in high-temperature hydrogen separation. Dissertation, Technical University of Munich (2010

[0020] Fischer, W. (1967). On the kinetics of hydrogen permeation through nickel. Journal of Natural Science A, 22(10), 1581-1586. doi:10.1515 / zna-1967-1020

[0020] Santucci, A., S. Tosti, A. Basile, (2013). Handbook of Membrane Reactors; Alternatives to palladium in membranes for hydrogen separation: nickel, niobium and vanadium alloys, ceramic supports for metal alloys and porous glass membranes., 183-217. doi:10.1533 / 9780857097330.1.183

[0020] Yukawa, H., Nambu, T, Y. Matsumoto, Y., (2014). Advances in Hydrogen Production, Storage and Distribution; Design of group 5 metal-based alloy membranes with high hydrogen permeability and strong resistance to hydrogen embrittlement., 341-367. doi:10.1533 / 9780857097736.3.341

[0020] Johnson, E.W., Hill, M.L., The Diffusivity of Hydrogen in Alpha Iron, (1960) Trans. Met. Soc., AIME 218, 1104-1112

[0020] Suzuki, Asuka; Yükawa, Hiroshi (2020). A Review for Consistent Analysis of Hydrogen Permeability through Dense Metallic Membranes. Membranes, 10(6), 120. doi:1 0.3390 / membranes10060120

[0020] Steward, S.A. Review of hydrogen isotope permeability through materials, report, August 15, 1983; [Livermore,] California. (https: / / digital.library.unt.edu / ark: / 67531 / metadc1066698 / : accessed March 25, 2024), University of North Texas Libraries, UNT Digital Library, https: / / digital.library.unt.edu

[0020] MADHUMITA GOSWAMI, T. MIRZA, A. SARKAR, SHOBHA MANIKANDAN, SANGEETA, SL VERMA, KR GURUMURTHY, VK SHRIKHANDE, GP KOTHIYAL, Preparation and characterization of magnesium-aluminum-silicate glass ceramics. Bull. Mater. Sci., 23, (5), 2000, 377-382. doi:10.1007 / BF02708387

[0020] J. Nixdorf. Fiber reinforcement of aluminum. Materials Science and Engineering (1974), 5(2), 84-95. doi:10.1002 / mawe.19740050208

[0020] Kainer KU, Bergmann HW, Mordike BL. Powder Metallurgically Produced Metal-Glass Composites. Powder Metallurgy. 1984;27(1):30-38. doi:10.1179 / pom.1984.27.1.30

[0020]

Claims

[1] Storage system for the storage and transport of hydrogen with hollow microspheres characterized by that metal and / or metal alloy and / or metal composite particles or mixtures thereof, which can be inductively heated, are embedded in the closed shells of the hollow microspheres. [2] Hollow microspheres according to claim 1 characterized by that they are hollow glass, ceramic, polymer, metal, carbon or composite spheres or mixtures thereof, whereby single-shell or multi-shell embodiments can be used. [3] Metal, metal alloy, metal composite particles according to claim 1 characterized by that they are made of ferromagnetic and / or non-ferromagnetic metals and, if possible, have a particle size slightly larger than the wall thickness of the hollow microspheres, so that they can completely penetrate the hollow microsphere walls without cracks or gaps. [4] Metal, metal alloy, metal composite particles according to claim 1 characterized by that the hydrogen permeability is very low at moderate temperatures such as room temperature and when the temperature is increased by a few or several hundred degrees Celsius it increases many times over, preferably by 2 to more than 4 orders of magnitude. [5] Metal composite particles according to one of the above claims characterized by that they are designed in the form of a core-shell structure or a multi-layer structure, wherein the core or the core layers consist of ferromagnetic material and the shell or the edge layers consist of oxidatively stable materials, and these materials optionally have particularly good hydrogen permeability at elevated temperatures. [6] Metal, metal alloy, metal composite particles according to one of the above claims characterized bythat they are provided with an additional adhesion-promoting layer to ensure a particularly good bond with the base casing material. [7] Storage system according to claim 1 characterized by that a larger quantity of hollow microspheres are combined in easily handled gas-permeable enclosures in order to easily move them locally, for example to pump them or to relocate them in batches, and in particular to further protect them from mechanical stress during these relocation processes. [8] Inductive heating according to claim 1 characterized by that non-ferromagnetic particles are used for eddy current induction by a low-frequency alternating field and, in contrast to ferromagnetic particles, a high-frequency alternating field is used to keep the skin depth low. [9] Ferromagnetic particles according to one of the above claims characterized bythat iron, in particular carbonyl iron, nickel, cobalt and a variety of their alloys, in particular nickel-phosphorus alloys, Heusler alloys and also non-metallic materials such as chromium dioxide, manganese arsenide, europium(II) oxide, with the highest possible Curie temperature, are used as base material. [10] Storage system according to one of the above claims characterized by that in addition to the hollow microspheres, closed microtubes or mixed-pore, i.e. closed-pore and open-pore microfoam, are also used.

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