Device for providing hydrogen

Abstract

Device for providing hydrogen, comprising a device (2) for generating hydrogen by electrochemical splitting of water into hydrogen and oxygen and a device (3) for compressing the generated hydrogen into at least one pressure vessel (4), wherein the pressure vessel (4) is tubular in form and is substantially located below the earth's surface (E), characterized by that the pressure vessel (4) with its substantial circumferential and base surface (5, 6) is surrounded by soil and / or rock, that the pressure vessel (4) has a storage capacity corresponding to an energy quantity of at least 70 MWh, that the pressure vessel (4) is made of a steel material, that the pressure vessel (4) is arranged in the ground in a surrounding casing (13) made of corrosion- and age-resistant material, and that the casing (13) is formed by a plastic tube (14) with at least one bottom (15).

Description

[0001] The invention relates to a device for providing hydrogen, comprising a device for generating hydrogen by electrochemical splitting of water into hydrogen and oxygen and a device for compressing the generated hydrogen into at least one pressure vessel, according to the preamble of claim 1.

[0002] Renewable energies are increasingly being used to generate electricity in a significant proportion of the total. However, the electricity generated by wind turbines or photovoltaic systems is sometimes produced at times that do not necessarily coincide with electricity consumption. Therefore, it is necessary to store the generated energy, for example in lithium-ion batteries, or alternatively, to store hydrogen, which can be produced by electrolysis of water using the electricity generated by photovoltaic or wind power systems. Furthermore, a widespread supply of hydrogen will be increasingly needed in the future, for example, to refuel fuel cell vehicles, which can operate emission-free on hydrogen. This will also be necessary to supply households and, in the future, industrial plants with hydrogen.

[0003] This requires a continuous supply of hydrogen, as a cyclical or even stochastic supply of energy directly from photovoltaic or wind power plants to the aforementioned consumers is insufficient.

[0004] There are already semi-technical or technical, smaller systems known in which a renewable energy source with a battery storage system is also connected to smaller end consumers in apartments or houses.

[0005] US 2012 / 0166013A1 describes such a system, in which the current performance of a photovoltaic system, the system's battery storage, and the connected consumers are determined during operation, and the best possible energy distribution to the aforementioned components of the system is calculated and controlled.

[0006] US 2008 / 0135403A describes a photovoltaic system with a solar thermal system, an electrolyzer, and a hydrogen storage system, whereby hydrogen is produced and stored using solar power through the electrolyzer.

[0007] US patent 2009 / 0322090A1 discloses an energy storage system. This system includes a hydrogen gas storage unit connected to a power plant. It also incorporates an electrolyzer and a hydrogen gas pressure vessel, which can be located underground.

[0008] WO 2015 / 080 353 A1 describes a high-pressure liquid storage tank that may be located in a recess below the earth's surface. This storage tank or reservoir may have a vertically oriented body made of steel.

[0009] Liquid hydrogen, cooled to -253°C and with a significantly higher energy content (8.5 MJ / liter) than gaseous hydrogen, is also used to supply fuel cell vehicles.

[0010] Large-scale technical devices and systems for providing hydrogen to supply an entire national economy and enabling the widespread use of fuel cell vehicles or other hydrogen consumers are unknown. In particular, no suitable hydrogen storage facilities with a sufficiently large energy capacity are known.

[0011] Based on this state of the art, the invention is based on the objective of providing a device for supplying hydrogen, in particular a suitable pressure vessel, which enables the nationwide supply and use of hydrogen in an entire country and which requires little space for its construction.

[0012] The problem is solved by a device for providing hydrogen having the features of claim 1.

[0013] By having a tubular pressure vessel of the device, arranged essentially below the earth's surface in such a way that its substantial circumferential and base surfaces are encased in soil and / or rock, having a storage capacity of at least 70 MWh, being made of a steel material, being arranged in the ground within a surrounding casing made of corrosion- and age-resistant material, and the casing being formed by a plastic pipe with at least one base, a technical measure is specified which makes it possible to provide a sufficiently large amount of energy with minimal land use.

[0014] Multiple pressure storage systems can also be used to enable a nationwide supply of hydrogen to an economy.

[0015] Preferred embodiments are set forth in the dependent claims.

[0016] Advantageously, the pressure vessel is formed as a cylindrical tube, and is embedded in the ground in such a way that its longitudinal axis is approximately perpendicular to the earth's surface. This allows it to be sunk into the ground using known drilling devices, requires little built-up area, is protected against external damage, and is safely positioned for the user.

[0017] The pressure vessel and borehole assembly can have more than one material layer – namely, that of the pressure vessel's shell. It can be advantageous to construct the pressure vessel wall from a preferably corrosion-resistant steel material, onto which one or more layers of corrosion protection and / or one or more layers of insulating material are applied in a continuous and sealing manner. This ensures that corrosive influences from the surrounding soil cannot impair the structure of the pressure vessel material. Furthermore, it prevents the cryogenic hydrogen from experiencing any significant temperature increase due to external heat input into the pressure vessel.

[0018] The pressure vessel can also be partially enclosed by a plastic pipe that is inserted into the borehole before the pressure vessel is installed. The plastic pipe prevents the borehole from collapsing and creates favorable conditions for inserting the pressure vessel into the borehole.

[0019] The insulation layer can be formed in solid form by a layer of insulating foam, or it can be formed by a sole or additional insulating fill surrounding the pressure vessel in the borehole.

[0020] To create the largest possible storage volume in a very small space, the borehole can reach a depth of approximately 600 m and accommodate a large number of pressure vessels. In this way, a very large energy storage system can be created, for example, in close proximity to power plants generating electricity, such as photovoltaic or wind power plants, suitable for supplying consumers with hydrogen regionally and even nationally. Furthermore, the use of large pressure vessels enables power plant types that are not typically capable of providing baseload power, such as wind or solar power plants, to achieve this capability.

[0021] In a particularly preferred embodiment, the pressure vessel has standard dimensions with regard to its diameter, such as a diameter of 2400 mm.

[0022] It can be formed or welded from several, preferably three, pipe elements. This design feature enables the precise and cost-effective production of the three pipe elements and their standard-compliant connection to one another.

[0023] The borehole itself preferably has a diameter of 2800 mm, so that the insertion of the pressure vessel(s) presents no technical difficulties.

[0024] It is advantageous to create several boreholes near a hydrogen-generating power plant, preferably arranged in a series or in several adjacent rows, in order to accommodate a large number of pressure vessels.

[0025] In this way, for example, new power plants utilizing renewable energies can be built on the sites of obsolete conventional coal-fired power plants, and the associated storage capacity can be accommodated on the vacated land. This allows existing space to be used for a new, modern power plant design, such as the one according to the invention.

[0026] The pressure vessels arranged in series can be fluidically connected to each other to form individual groups that are functionally linked with regard to the operation of the power plant.

[0027] In this way, power plants can be built distributed across an entire country, capable of supplying hydrogen consumers of all kinds – vehicles, stationary plants, households, etc. – with a pipeline network connected to the power plants and the pressure vessels and compressor facilities being advantageous in order to make the hydrogen available across the entire country.

[0028] The pressure vessel(s) with attached compressor units are also capable of supplying long-distance pipelines, such as those running along major transport routes, thus enabling international hydrogen trade. The invention will now be described in more detail with reference to exemplary embodiments and illustrated with the drawings.

[0029] They show: Fig. 1 a schematic view of a device according to the invention for providing hydrogen in the manner of a power plant, Fig. 2 a schematic, not to scale longitudinal section through a pressure vessel for hydrogen according to the invention of the device in Fig. 1.

[0030] In Fig. Figure 1 shows a schematic view of a device 1 for providing hydrogen in the form of a power plant 21, wherein water is split into hydrogen and oxygen using electrical energy in the device 1. The electrical current is provided for this purpose by a wind turbine, which is arranged in an ensemble with the device 1. The electrical current generated by the wind turbine supplies, among other things, a device 2 for producing hydrogen by electrochemical splitting. The hydrogen is purified and dried in a gas processor (not shown) and compressed in several compression stages by means of a hydrogen compression device 3.

[0031] It can be cooled or deep-frozen and stored in one or more pressure vessels 4 in a gaseous or liquid state (compare Fig. 2) be stored. The compression device 3 can, for example, be a diaphragm compressor. It can also be used to maintain constant pressure in the pressure vessels 4.

[0032] The pressure vessel 4 is tubular in the form of a cylindrical tube 7 with a bottom and a lid and is essentially, preferably completely, embedded below the earth's surface E in a borehole 18. As a result, its circumferential and bottom surfaces are encased in soil or rock. A single pressure storage vessel 4 has a storage capacity of 70 MWh or more of hydrogen.

[0033] The longitudinal axis 8 of the pressure accumulator 4 runs perpendicular to the earth's surface E. This allows it to be inserted into a borehole 18 constructed using known earth drilling equipment (compare Fig. 2) Cost-effective and, above all, safe against external influences. The pressure in pressure vessel 4 can, for example, be 200 bar.

[0034] The pressure vessel 4 itself is preferably made of a steel material, but can also be made of wound fiber composite material or in another construction method.

[0035] A wall 10 of the pressure vessel 4 can also be formed from more than one layer 11, 12. It has a surrounding casing 13 made of corrosion- and age-resistant material. The casing 13 can, for example, be formed by a single- or multi-layered plastic pipe 14 with a base 15.

[0036] The plastic pipe 14 is advantageously inserted into the borehole 18 before the pressure vessel 4 is inserted into the borehole 18, thereby enabling the pressure vessel 4 to be inserted into the borehole 18 in a manner that protects it.

[0037] On its outer surface 16 facing the heat source, the casing 13 has a flat insulating layer 17 that prevents heat from entering the pressure vessel 4 from the outside. The insulating layer 17 is formed in the form of an insulating foam, but can also be formed as a liquid jacket containing a cooling liquid to lower the temperature of the hydrogen in the pressure vessel 4.

[0038] In a single borehole, which can be many hundreds of meters deep, for example 600 m, a large number of pressure vessels 4 can be installed in this way. They can be connected in parallel and fluidically linked to each other.

[0039] How Fig. As shown in Figure 2, the pressure vessel 4 can have a diameter D of 2400 mm. It can also be formed from several pipe elements 19, 19", 19", which are sealed together. The borehole 18 itself can have a diameter d of 2800 mm.

[0040] On its upper side 23 is the borehole in which in Fig. In the embodiment shown in Figure 2, the borehole 18 is closed by a 250 mm thick reinforced concrete cover 24. Preferably, a manhole 25 with a diameter of, for example, 1000 mm is cut into the cover 24. The cover 24 allows access to the pressure vessel 4 and provides access for maintenance of its gas connections (not shown). It can also serve for venting. The borehole 18 is also sealed at its base with a reinforced concrete base plate 26.

[0041] Boreholes 18 with pressure vessels 4 are preferably arranged in rows with preferably discrete spacing on a storage field of the power plant 21, so that a very large total storage capacity for hydrogen is provided in a small space. This total storage volume is sufficient not only to supply filling stations for hydrogen-powered rail vehicles 27 and road vehicles 28 in the immediate vicinity of the power plant 21, but is also suitable for supplying long-distance pipelines 22 for supra-regional, even cross-border, hydrogen supply.

[0042] The pressure storage device 4 according to the invention is also suitable for use as an offshore storage device in the seabed. Such devices could be installed in locations where coal-fired power plants currently exist. Fig. 1. Install the outlined power plant concepts without requiring additional space.

[0043] The use of such pressure storage 4 makes a power plant design like that of wind or solar power plants also capable of baseload power. Reference symbol list 1 Device 2. Hydrogen production facility 3 Compaction device 4 pressure vessels 5 Circumferential area, v. 4 6 Floor area, v. 4 7 tube, cylindrical 8 Longitudinal axis, v. 4 9 - 10 Wall, v. 4 Layer 11, v.4 12th layer, v. 4 13 Envelope 14 plastic pipes 15 Floor 16 outdoor area 17 Insulating layer 18 boreholes 19, 19', 19" pipe element 20 storage facility 21 Power Plant 22 Long-distance pipeline 23 Top side, v. 18 24 lids 25 manhole 26 Base plate, v. 18 27 Rail vehicle 28 road vehicle Earth's surface D diameter, v. 4 d diameter, v. 18

Claims

[1] Device for providing hydrogen, comprising a device (2) for generating hydrogen by electrochemical splitting of water into hydrogen and oxygen and a device (3) for compressing the generated hydrogen into at least one pressure vessel (4), wherein the pressure vessel (4) is tubular in form and is substantially located below the earth's surface (E), characterized by , that the pressure vessel (4) with its substantial circumferential and base surface (5, 6) is surrounded by soil and / or rock, that the pressure vessel (4) has a storage capacity corresponding to an energy quantity of at least 70 MWh, that the pressure vessel (4) is made of a steel material, that the pressure vessel (4) is arranged in the ground in a surrounding casing (13) made of corrosion- and age-resistant material, and that the casing (13) is formed by a plastic tube (14) with at least one bottom (15). [2] Device according to claim 1, characterized by , that the pressure vessel (4) is formed as a cylindrical tube (7) with a bottom and a lid and that the longitudinal axis (8) of the pressure vessel (4) is aligned approximately perpendicular to the earth's surface (E). [3] Device according to one of claims 1 or 2, characterized by , that a wall (10) of the pressure vessel (4) is formed from more than one material layer (11, 12), [4] Device according to any one of claims 1 to 3, characterized by , that the pressure vessel (4) and / or the casing (13) have at least on its outer surface (16) facing the ground a planar insulating layer (17). [5] Device according to claim 4, characterized by , that the covering (13) is formed in the form of insulating foam or insulating fill. [6] Device according to any one of claims 1 to 5, characterized by that one or more pressure vessels (4) are arranged in a borehole (18) reaching a depth of approximately 600 m. [7] Device according to any one of claims 1 to 6, characterized by that the pressure vessel (4) has a diameter (D) of approximately 2400 mm [8] Device according to any one of claims 1 to 7, characterized by , that the pressure vessel (4) is formed from several, preferably 3, pipe elements (19, 19', 19") which are sealed together. [9] Device according to any one of claims 1 to 8, characterized by , that the pressure vessel (4) is arranged in a borehole (18) of approximately 2800 mm diameter (d). [10] Device according to any one of claims 1 to 9, characterized by , that in a storage facility (20) several pressure vessels (4) are arranged in boreholes (18) placed next to each other, in a row or in other arrangements into the ground. [11] Device according to claim 10, characterized by , that the pressure vessels (4) are fluidically connected to each other. [12] Device according to any one of claims 1 to 11, characterized by , that the pressure vessel (4) is part of a power plant (21) which generates electricity for the electrochemical splitting of water into hydrogen and oxygen by utilizing alternative, renewable energy sources (wind, solar radiation, hydropower, geothermal energy). [13] Device according to any one of claims 1 to 12, characterized by , that the hydrogen contained in the pressure vessel (4) is used to power internal combustion engines for motor vehicles, for electricity generators and other machines powered by internal combustion engines. [14] Device according to any one of claims 1 to 13, characterized by , that the pressure vessel (4) serves to supply long-distance pipelines (22) for hydrogen in order to supply consumers, such as hydrogen filling stations or households, with energy.

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