WO2017178471A1

WO2017178471A1 - Storage device for storing hydrogen-carrier medium, system comprising such a storage device and method for storing hydrogen-carrier medium

Info

Publication number: WO2017178471A1
Application number: PCT/EP2017/058648
Authority: WO
Inventors: Berthold Melcher; Matthias KUSCHE
Original assignee: Hydrogenious Technologies Gmbh
Priority date: 2016-04-12
Filing date: 2017-04-11
Publication date: 2017-10-19
Also published as: EP3443258A1; DE102016206106A1

Abstract

A storage device for storing hydrogen-carrier medium comprises a storage vessel (4) which has a longitudinal axis (3) and is intended for storing the hydrogen-carrier medium in a layered manner in dependence on the degree of hydrogenation (h) thereof, and also comprises a filling/removal unit (5) which is connected to the storage vessel (4) and is intended for filling and/or removing hydrogen-carrier medium. The degree of hydrogenation of the hydrogen-carrier medium stored in the storage vessel can be determined by means of a condition-monitoring unit (25). A regulating unit allows for regulated filling and/or removal of hydrogen-carrier medium, in particular in dependence on the degree of hydrogenation (h) thereof.

Description

Storage device for hydrogen carrier medium, system comprising such a storage device and method for storing hydrogen carrier medium

The present patent application claims the benefit of German Patent Application DE 10 2016 206 106.2, the contents of which are incorporated herein by reference.

The invention relates to a storage device for hydrogen carrier medium, a system with such a storage device and a method for storing hydrogen carrier medium.

DE 10 2013 223 589 A1 discloses a system for storing hydrogen by means of a hydrogen carrier medium in the form of a liquid organic hydrogen carrier (LOHC). By means of a reversibly executable circulation process, the hydrogen carrier medium can be charged or discharged with hydrogen gas. The hydrogen carrier medium is advantageous to handle. Separate storage containers are provided for storing the loaded hydrogen carrier medium and the discharged hydrogen carrier medium.

Storage containers are also known from DE 10 2013 202 779 AI, DE 10 2008 063 278 B4, DE 10 2006 034 508 AI, CA 2 524 846 AI, CN 204 986 395 U, EP 1 878 714 AI, US

2007/0031325 AI, US 7,052,671 B2.

The present invention has for its object to simplify the storage of hydrogen carrier medium. The object is solved by the features of claims 1, 13 and 14. The gist of the invention is that a storage device allows storage of loaded and unloaded hydrogen carrier media in a single storage container. The loaded hydrogen carrier medium has a first degree of hydrogenation hi and the discharged hydrogen carrier medium has a second degree of hydrogenation h ₂ , wherein hi h ₂ , in particular hi> h ₂ , applies. In particular, the loaded hydrogen carrier medium and the discharged hydrogen carrier medium are arranged in the single storage vessel without any mechanical separation of the hydrogen storage medium Partial volumes. In particular, mechanical separating elements in the single storage container are dispensable.

In particular, at least one filling / removal unit is provided for each partial volume, so that each partial volume can be filled and withdrawn separately and in particular independently of one another.

The storage container can be used stationary, in particular in a fixed installation for loading and / or unloading of hydrogen carrier medium. Additionally or alternatively, the storage container can be mobile or integrated on a transport vehicle, in particular a tanker truck, a train wagon and / or on a ship. In the storage container, the arrangement of hydrogen carrier medium of different degrees of hydrogenation and / or different temperature is possible. This means that hydrogen carrier medium loaded in a loading reactor and hydrogen carrier medium discharged in a final charge reactor can be stored together, in particular simultaneously, in the storage container. Accordingly, hydrogen medium can be stored in the storage container, which is still to be loaded in the loading reactor or to be discharged in the discharge reactor. A gas phase may also be located in the storage container, in particular hydrogen gas which has been outgassed from the at least partially charged hydrogen carrier medium. The storage tank will also contain a quantity of heat due to the enthalpy of the incoming and outgoing media. According to the invention, it has been recognized that advantageous storage is made possible in that the hydrogen carrier medium has different densities as a function of the degree of hydrogenation. Hydrogen carrier medium of different degrees of hydrogenation will deposit layered in the storage container density-dependent. The storage container is in particular a layered storage. As the hydrogen carrier medium is used in particular LOHC, which is liquid and in particular allows advantageous handling as a storage medium. The storage container can also be used for other storage media. It is essential that the density of the hydrogen carrier medium is dependent on the degree of hydrogenation. The gas phase will be located in the storage container due to the difference in density above the storage media. The gas phase may, for example, have an inert gas, in particular nitrogen or helium. Additionally or alternatively, the gas phase may also include hydrogen gas. In principle, almost every gas in the gas phase can be arranged in the storage container. If hydrogen gas as Gas phase is provided in the storage container, the storage container can be used as a hydrogen gas storage and / or as a gas buffer container. Such a buffer container is advantageous in a system for loading and / or unloading hydrogen carrier medium, in particular based on LOHC, in order to provide hydrogen gas at a defined pressure level, for example for a fuel cell or a hydrogen gas burner for dehydrogenation. The buffer tank can also absorb a hydrogen gas stream, for example from the electrolysis, wherein the hydrogen gas stream can be subject to pressure fluctuations. The buffer container thus makes it possible to compensate for pressure fluctuations. The inclusion of hydrogen gas in the buffer tank also allows for energy storage.

A tempered storage tank, so a storage tank with external heating, allows preheating of the LOHC, in particular to reduce the viscosity and thus to reduce pressure losses and to improve the handling of the LOHC, in particular to simplify its pumpability. The handling of LOHC in the plant for loading and / or unloading of hydrogen is improved.

The storage container has in particular a longitudinal axis, which is in particular substantially vertical and in particular vertically oriented. The longitudinal axis of the storage container may also be inclined relative to the vertical. For example, an angle of inclination to the vertical of at most 60 °, in particular at most 45 ° and in particular exactly 45 ° is conceivable. Advantageously, the cross-sectional area of the storage container is constant in a plane perpendicular to the longitudinal axis. In particular, the storage container has a substantially cylindrical shape. It is also possible that the cross-sectional area of the storage container is variable along the longitudinal axis. For example, a substantially spherical container is conceivable which has a maximum cross-sectional area in a middle region along the longitudinal axis. The poles of the spherical shape can be flattened. In this central region hydrogen carrier medium with approximately average hydrogenation degree of, for example, 40% to 60% will be present. In the upper and lower regions, which have a comparatively smaller cross-sectional area, hydrogen carrier medium with a high or low degree of hydrogenation is stored. A spherical storage tank provides a realistic storage needs. High degrees of hydrogenation are produced with a comparatively low hydrogenation rate or lower hydrogenation rate. Low degrees of hydrogenation are achieved with comparatively increased hydrogenation rate or high Dehydrierleistung made. The required storage volume is therefore comparatively small. In contrast, partially loaded and / or partially discharged hydrogen carrier medium is present in large volumes, which can be advantageously stored in the central region of the spherical storage container. Alternatively, it is also conceivable that the storage container has a conical or frusto-conical shape, for example, the provided volume of small degrees of hydrogenation below and the higher degrees of hydrogenation, such as greater than 80%, could be arranged at the top. Depending on a volume requirement, the cone may be arranged with the tip up or down. The cone container can be arranged variably inclined with its longitudinal axis with respect to the vertical in order to change the size of the horizontal surface. The degree of hydrogenation of the hydrogen carrier medium is 100% when the hydrogen carrier medium is completely loaded. The degree of hydrogenation is 0% when the hydrogen carrier medium is completely discharged. By virtue of the fact that the hydrogen carrier medium can be fed to the storage device independently of the actual degree of hydrogenation, which can in particular assume an arbitrary value between 0% and 100%, and can be stored there easily as a function of the degree of hydrogenation, storage of the hydrogen carrier medium is substantially simplified with the storage device. The removal of hydrogen carrier medium from the storage device is flexibly possible. Hydrogen carrier medium with different degrees of hydrogenation and / or with different temperature levels as well as hydrogen gas can be temporarily stored in the storage device and provided for an intended reaction, ie either loading, ie hydrogenation, or discharging, ie dehydrating. In particular, this makes it possible to flexibly adapt the hydrogen carrier medium to, for example, variable, fluctuating conditions of energy storage and the provision of energy from renewable energy sources, in particular the provision of energy by means of the buffered hydrogen carrier medium at a later time. For example, high energy consumption can be effectively stored by performing partial hydrogenation at high power but low conversions. At low energy levels, substantially complete hydrogenation at low power could occur. Accordingly, with low energy consumption, a substantially complete discharge could take place at reduced power. At high energy demand, a partial discharge could occur at high power. In particular, it is therefore not necessary to completely charge the hydrogen carrier material in each case or to completely discharge it To allow storage of the hydrogen carrier medium. As a result, the storage device is particularly suitable for energy from renewable energy sources. The fact that a single storage container is sufficient for storing laden and discharged hydrogen carrier medium, investment costs, space requirements, logistics and in particular regulatory technical effort for the storage of hydrogen carrier medium are reduced. For filling and / or removal of hydrogen carrier medium, a filling / removal unit is provided on the storage container. In particular, the storage device is suitable for storing products from the hydrogenation and from the dehydrogenation, that is to say in particular partially hydrogenated and / or partially dehydrogenated hydrogen carrier medium. According to the invention, it has additionally been recognized that the density of the hydrogen carrier medium is temperature-dependent. The density of the hydrogen carrier medium decreases with increasing temperature, in particular within a temperature range from 0 ° C to 200 ° C.

This makes it possible for the hydrogen carrier medium in the stratified storage to be stored in different temperature layers as a function of the temperature. The storage container can be used in particular as a heat storage. In particular, in a plant for loading and / or unloading of hydrogen waste heat from exothermic reactions such as the electrolysis of hydrogen in an electrolyzer and / or the hydrogenation of the hydrogen carrier medium can be recorded in a hydrogenation reactor and stored in the storage device. The heat may be provided to preheat media and / or to provide heat of reaction for endothermic reactions, such as dehydrogenation of at least partially charged hydrogen carrier medium in a dehydrogenation reactor, or the conversion of hydrogen into a fuel cell. Additionally or alternatively, the waste heat stored in the storage device can be used for building heating and / or water heating. The effectiveness of the storage device as a heat storage is improved when a thermal insulation is provided on the storage container. This can be done in particular by a arranged on an outer side of the storage container insulating layer of a thermally insulating material.

The storage device can be particularly advantageous in a change between the operation of a system for loading and / or unloading of hydrogen carrier medium in various Operating points are used. In the transition between two operating points, the system is operated transiently. The result is hydrogen carrier medium with varying degree of hydrogenation, which can be advantageously absorbed and stored in the storage device. In prior art systems equipped with conventional memory devices, the uptake of storage medium of varying degrees of hydrogenation is avoided. The hydrogen carrier medium produced during the transient mode of operation must therefore be separately stored and / or disposed of in systems known from the prior art. The storage device according to the invention thus makes it possible, in particular, to take up hydrogen carrier medium with an undefined degree of hydrogenation and / or mixtures of hydrogen carrier media of different degrees of hydrogenation. The hydrogen carrier medium can be stored depending on the degree of hydrogenation in the associated layer and additionally hydrogenated or dehydrogenated at a later time.

The storage pressure with which the hydrogen carrier medium is stored in the storage container, in particular ambient pressure, ie 1 bar. The liquid hydrogen carrier medium is stored in the storage container, in particular under ambient conditions. An increased storage pressure, which is required in particular for the storage of hydrogen gas, is unnecessary. An increased storage pressure between 1 bar and 16 bar within the storage container may be advantageous if, in addition to the liquid hydrogen carrier medium of different degrees of hydrogenation, gaseous hydrogen should also be stored in the storage container.

At least one filling / extraction element according to claim 2 allows immediate access to the storage container via the filling / removal unit. In the simplest case, the filling / removal element is designed as an opening, via which the hydrogen carrier medium can be fed into the storage container or removed therefrom. The opening can in particular be designed directly in the storage container itself. The filling / removal element may also be a nozzle.

A riser according to claim 3 allows an additional simplification of the removal and the supply of hydrogen carrier medium. On the riser, a filling / removal element can be arranged directly. In particular, several filling / Removal elements to be arranged on the riser. The riser is designed for example as a pipe socket or as a dip tube.

A variable arrangement of the riser relative to the storage container according to claim 4 enables a targeted displacement and in particular arrangement of the filling / removal

Elements inside the storage tank. As a result, targeted supply of hydrogen carrier medium into or targeted removal from various layers from the storage container is possible, in particular. A filling / removal unit according to claim 5 ensures an uncomplicated, in particular flexible and / or continuous, removal and supply of hydrogen carrier medium.

A control valve according to claim 6 allows a controlled, in particular quantitatively controlled, removal and filling with hydrogen carrier medium. By using the control valve, a continuous filling and emptying of the storage container is made possible. A control concept adapted to a respective environmental condition can be realized.

A heat exchanger according to claim 7 allows the effective removal of residual heat of the hydrogen carrier medium. The heat exchanger can also serve to supply heat to the hydrogen carrier medium. The hydrogen carrier medium may be warmed up, for example, as a result of a previous loading or unloading process. The stored in the storage tank hydrogen carrier medium is effectively cooled. As the temperature in the reservoir decreases, Brownian motion is reduced. Unwanted mixing of the hydrogen carrier medium and in particular undesirable flows in the storage container are thereby reduced and in particular prevented. The heat dissipated from the storage tank can be used efficiently, for example, as preheating for the reactors for loading and / or unloading. The heat from the storage tank can also be used for heating buildings or for air conditioning to cool a building. The heat exchanger can alternatively also serve to heat the hydrogen carrier medium, that is to say to supply heat to the hydrogen carrier medium. For example, it is advantageous to preheat the hydrogen carrier medium for better pumpability, in particular to a temperature above the pour point of the hydrogen carrier medium. The pour point for LOHC is around 5 ° C.

A control unit according to claim 8 allows the controlled filling and / or removal of hydrogen carrier medium. For the controlled filling and / or removal is advantageously a pump, which can be controlled in particular via the control unit. Instead of the pump, the targeted filling and / or removal of the hydrogen carrier medium can be achieved by regulating a diaphragm pressure and / or taking into account the geodetic height. The control unit forms the basis for a holistic process control. The control unit is an essential component of a process control technology, in particular to adjust the degree of hydrogenation and / or the temperature of the hydrogen carrier medium in the storage container online, ie continuously, to the performance of a hydrogenation reactor and / or a dehydrogenation reactor. A level monitoring unit according to claim 9, in particular at least one

Has fill level sensor ensures a trouble-free, especially uninterrupted, regulated, continuous flow for filling and / or removal of hydrogen carrier medium. A condition monitoring unit according to claim 10, which has in particular at least one condition sensor, makes it possible to ascertain and / or monitor the degree of hydrogenation and / or the temperature of the hydrogen carrier medium stored in the storage container. As a result, in particular, an energy amount stored in the storage container can be determined. This makes it possible, in particular, to display, for example, as a function of a predicted energy requirement or to initiate a filling of the storage container with loaded hydrogen carrier medium directly. In particular, it is possible to determine the degree of hydrogenation of the hydrogen carrier medium to be filled prior to filling by means of a separate condition monitoring sensor of the condition monitoring unit. As a result, a targeted supply of the hydrogen carrier medium in the storage container is possible. The at least one state sensor is a measuring sensor which is suitable for detecting a physical and / or chemical property, ie a state, which correlates with the degree of hydrogenation and / or at least partially with the temperature. The condition monitoring unit may be, for example, a density monitoring unit with at least one density sensor. The condition monitoring unit may additionally or alternatively be a refractive index monitoring unit with at least one refractive index sensor in order to measure the degree of hydrogenation of the hydrogen carrier medium. The refractive index of the hydrogen carrier medium is dependent on the degree of hydrogenation. From the degree of hydrogenation, the density can be calculated. The degree of hydrogenation can also be carried out by means of nuclear magnetic resonance spectroscopy, also NMR spectroscopy. In this case, the condition monitoring unit would be embodied as a nuclear magnetic resonance monitoring unit having at least one nuclear magnetic resonance sensor. The nuclear magnetic resonance depends on the degree of hydrogenation. In nuclear magnetic resonance spectroscopy, a sample of hydrogen carrier medium can be analyzed offline in an NMR spectroscope, in particular outside the storage container. As condition monitoring unit can also serve a viscosity monitoring unit with at least one viscometer for determining viscosity. The viscosity of the hydrogen carrier medium depends on the degree of hydrogenation. In particular, several state sensors are provided in order to carry out measurements as a function of the fill level. By means of the condition monitoring unit, a total energy content of the storage container can be determined. In particular, it is possible to determine the respective energy content of a layer having a defined degree of hydrogenation of the hydrogen carrier medium.

Separating elements according to claim 11 make it possible to divide the storage container into separate storage areas, in order in particular to subdivide the hydrogen carrier medium of different degrees of hydrogenation, in particular different degrees of hydrogenation. It is possible to set storage areas with different temperature levels, but similar, in particular identical degree of hydrogenation. Furthermore, it is possible to realize storage areas with different degrees of hydrogenation and different temperature levels. It is therefore conceivable to arrange hydrogen carrier medium with a degree of hydrogenation between 70% and 100% in a first storage area. Another storage area could have hydrogen carrier medium with a degree of hydrogenation between 30% and 70%. In addition, a third storage area could be provided in which hydrogen carrier medium with a degree of hydrogenation of 0% to 30% is provided. With such a division of the storage areas, hydrogen carrier medium can be assigned unambiguously as a function of its degree of hydrogenation and stored in a storage area provided for this purpose. This makes it possible to categorize the hydrogen carrier medium as a function of the degree of hydrogenation. It is also conceivable one With regard to the degrees of hydrogenation, overlapping selection of the storage areas can be defined, for example by providing hydrogen carrier medium with a degree of hydrogenation between 40% and 100% in a first storage area, wherein hydrogen storage medium having a degree of hydrogenation of 0% to 60% is provided in a second storage area separate therefrom. Hydrogen carrier medium with a degree of hydrogenation between 40% and 60% could thus be stored in this embodiment both in the first storage area and in the second storage area. This allows redundancy of hydrogen carrier medium of certain degrees of hydrogenation. In particular, each storage area is assigned at least one filling / removal element.

A reassurance element according to claim 12 reduces the risk of undesired mixing of the hydrogen carrier medium of different layers, ie different degrees of hydrogenation and / or different temperatures. In particular, the calming element is designed as a guide plate and / or as a permeable calming body in the form of a perforated tube.

A system for loading and / or unloading of hydrogen has, in addition to the storage device, an associated hydrogenation reactor and / or a dehydrogenation reactor. Such a system can be used as a circulatory system. Hydrogen carrier medium can be loaded with hydrogen in the hydrogenation reactor and stored in the storage device for energy storage. For energy release, loaded hydrogen carrier medium can be removed from the storage device and discharged in the dehydrogenation reactor, so that the released hydrogen can be used for energy generation, for example in a fuel cell. It is also conceivable to provide a combined reactor in which both a hydrogenation reaction and a dehydrogenation reaction are possible in a single reactor vessel, depending on a catalyst used and / or as a function of pressure and temperature.

Additionally or alternatively, the system may also include a pump connected to the storage device, a compressor connected to the storage device, a circulation line connected to the storage device to allow a circulation flow for the hydrogen carrier medium and / or for a heat exchange medium, one with the storage reservoir. electrolyzer, a fuel cell connected to the storage device, a purification unit connected to the storage device, a burner connected to the storage device, an external heat source connected to the storage device, an external heat sink connected to the storage device.

The system may also include external peripheral components such as additional storage containers and / or buffer containers. Additional system components may also be provided such as pumps, compressors, heat exchangers, apparatus for purification and / or sensors, wherein these system components are arranged in particular in the periphery of the hydrogenation reactor, the de-hydrogenation reactor and / or the storage device. In particular, the plant comprises all components which are required for carrying out the LOHC process, and in particular containers and / or tanks for gases and / or liquids.

In particular, the storage device is integrated into the system for performing the LOHC overall process. The LOHC overall process comprises the provision of hydrogen by means of electrolysis, wherein the electric current required for the electrolysis has been generated in particular by means of regenerative methods. The LOHC overall process comprises hydrogenating the hydrogen carrier medium with the hydrogen from the electrolysis, storing the hydrogenated hydrogen carrier medium, dehydrogenating the hydrogen carrier medium in a dehydrogenation reactor and passing the hydrogen from the dehydrogenation reactor into a fuel cell or other hydrogen consumer. The storage device may additionally be combined with other hydrogen sources and / or hydrogen sinks, such as hydrogen from refineries and / or waste hydrogen from chlorine production. The storage device can also be connected to other heat sources and / or heat sinks.

A method for storing hydrogen carrier medium provides that hydrogen storage medium is stored in the provided storage device as a function of its degree of hydrogenation, in particular in layers. The advantages of the method correspond essentially to the advantages of the memory device, to which reference is hereby made. In the storage device, hydrogen carrier medium which originates from a hydrogenation reactor and / or from a dehydrogenation reactor can be used directly and in particular also in an only partially hygroscopic manner. driert and / or dehydrated state are saved. A removal of the hydrogen carrier medium can be carried out accordingly, ie a complete loading and / or unloading of the hydrogen carrier medium is not required for the removal from the storage device.

An essential finding is that the hydrogen carrier medium has density differences and / or density gradients as a function of the degree of hydrogenation and / or as a function of the temperature. Typically, the dependence of the density on the degree of hydrogenation is more pronounced than the dependence on the temperature. The storage device can be designed exclusively depending on the degree of hydrogenation or exclusively in a temperature-dependent or combined manner, that is to say it is designed to be hydrogenation-grade and temperature-dependent. When operating exclusively as a function of the degree of hydrogenation, it is advantageous to keep the storage container isothermally at a low temperature level, in particular in a temperature range from 20 ° C to 100 ° C and in particular from 20 ° C to 60 ° C. The indicated temperatures are also related to the temperature level of the heat source, in particular if the storage device serves as a heat storage. For this purpose, a thermal insulation of the storage container is advantageous.

In the method, it is thus possible to store a first portion of hydrogen carrier medium having a first degree of hydrogenation hi and a second portion of hydrogen carrier medium having a second degree of hydrogenation h ₂ in one and the same storage container and to remove it at a later time again. In particular, hi h ₂ , in particular hi> h _2, applies. The incorporation of the hydrogen carrier medium with different degrees of hydrogenation hi, h ₂ can take place simultaneously, at different times or overlapping in time. In particular, the filling of the storage container with the different storage quantities of the hydrogen carrier medium is possible independently of one another. A first layer comprising the first quantity of the hydrogen carrier medium having the first degree of hydrogenation hi and a second layer of the hydrogen carrier medium having the second degree of hydrogenation h ₂ are formed in the storage container, wherein the two subsets of layer boundaries are arranged separately in the storage container.

In an operation of the storage device as a function of the temperature, a thermal insulation and an isothermal operation are advantageous. A method according to claim 15 simplifies the storage in the storage device, wherein the filling and / or removal of the hydrogen carrier medium takes place in a targeted manner in particular.

Further advantageous embodiments, additional features and details of the invention will become apparent from the following description of exemplary embodiments with reference to the drawing. 1 is a schematic view of a system with a storage device according to the invention, a schematic detail view of the storage device according to a second embodiment, an enlarged detail view of a filling / removal unit of the storage container in FIG 3, an illustration corresponding to FIG. 4 of a storage device according to a third exemplary embodiment, a representation corresponding to FIG. 3 of a storage device according to a fourth exemplary embodiment, FIG. 2 a representation of a system with a combined reactor for hydrogenating and dehydrogenating hydrogen carrier medium,

8 shows a representation corresponding to FIG. 3 of a memory device according to a fifth exemplary embodiment. A finding underlying a layered storage of hydrogen carrier medium in a storage device 1 according to FIG. 2 is shown in FIG. In the diagram, the density p for hydrogen carrier medium in the form of LOHC is given as a function of the degree of hydrogenation h at a temperature T of 25 ° C. LOHC is, for example, di-benzyl-toluene or perhydro-di-benzyl-toluene. For a hydrogenation degree h of 0%, the density p of the hydrogen carrier medium is at a maximum and is about 1.04 g / cm ³ . For the maximum hydrogenation h of 100%, the density p of the hydrogen carrier medium is minimal and is about 0.91 g / cm ³ . Between these minimum / maximum values results in an approximately linear relationship. The density p of the hydrogen carrier medium is directly proportional. In principle, the smaller the degree of hydrogenation h, the greater the density p of the hydrogen carrier medium. The dependence of the density p on the degree of hydrogenation also applies to other LOHC materials, in particular also to other hydrogen carrier media. On the basis of this finding, it has been found that hydrogen carrier medium of different hydrogenation degree h and / or different temperature T can be arranged in one and the same storage device 1, hydrogen carrier medium being layered as a function of the respective degree of hydrogenation h and / or the respective temperature due to the different density will order. Hydrogen carrier medium with a low degree of hydrogenation h has a comparatively higher density p and thus a higher specific gravity. Hydrogen carrier medium with reduced degree of hydrogenation h is comparatively heavy and will be located below the layer of hydrogen carrier medium with a higher degree of hydrogenation h. The layered arrangement of the hydrogen carrier medium as a function of its degree of hydrogenation h thus causes hydrogen carrier medium having a high degree of hydrogenation h to be arranged above a layer of hydrogen carrier medium having a reduced degree of hydrogenation h. In a substantially vertical storage vessel, heavy hydrogen carrier medium with reduced degree of hydrogenation h below and light hydrogen carrier medium with increased degree of hydrogenation h will be placed in the top of the storage vessel. Finally, a density gradient will develop depending on the degree of hydrogenation and temperature.

Hereinafter, a system 2 for loading and / or unloading of hydrogen will be explained in more detail. The system 2 has the storage device 1. The storage device 1 has a a longitudinal axis 3 having storage container 4. The storage container 4 is designed substantially cylindrical, with other, in particular cross-sectional shapes, are conceivable. The longitudinal axis 3 of the storage container 4 is oriented vertically. Disc-shaped layers of the hydrogen carrier medium form within the storage container 4 along the longitudinal axis 3, wherein the different layers of the hydrogen carrier medium each have a different degree of hydrogenation h. The layer formation is visible immediately after the introduction of hydrogen carrier medium into the storage container 4.

In particular, layer boundaries form between the layers of different degrees of hydrogenation h and / or different temperature T. Adjacent layers in the storage container 4 may have the same phases as, for example, liquid / liquid or different phases, such as, for example, liquid / gaseous. The phase is understood to mean the predominantly aggregate state of the hydrogen carrier medium in the respective layer. With a longer storage period of the hydrogen carrier medium, the layer boundaries can regress and a hydrogenation gradient along the longitudinal axis 3 can be established. The thinner the respective layer, the more uniform, ie more homogeneous along the layer thickness, is the associated degree of hydrogenation h and / or the associated temperature and / or other physico-chemical parameters. The formation of the gradient is dependent on the time t and can be slowed down, for example by reducing the temperature T. By mechanical flow control, in particular by means of baffles, an inadvertent mixing of hydrogen carrier medium different degrees of hydrogenation can be effectively prevented. In addition, the more homogeneously a particular layer is embodied, and the greater the distance of the respective degree of hydrogenation in the layers, the less pronounced the tendency for mixing. For example, it has been found that a first layer having a first degree of hydrogenation with 30% hi and a second layer with a second degree of hydrogenation h ₂ behave of 70% in a layered structure is generally stable over time. A self-mixing of these two layers does not essentially take place.

However, it is essential that the density of the hydrogen carrier medium depends on the degree of hydrogenation h and / or on the temperature T. A layered storage according to the invention is therefore also given if there are no discrete, separated by layer boundaries layers, but given a continuous layer course with a hydrogenation gradient. there it is conceivable that the storage container 4 is substantially completely filled with hydrogen carrier medium. But it is also an operation with only partially filled storage tank 4 possible. The storage device 1 further comprises a filling / removal unit 5. The filling

/ Removal unit 5 has a plurality of filling / removal elements 6, which are executed according to the embodiment shown as filling / removal openings in the outer cylinder jacket wall of the storage container 4, the bottom wall and the top wall. The filling / removal elements 6 in the form of the filling / removal openings are arranged spaced apart along the longitudinal axis 3. This makes it possible to remove hydrogen carrier medium of different degrees of hydrogenation from the storage container 4 and / or to fill it at a suitable point in the storage container 4. At the filling / removal openings in each case a connecting line 7 is connected, which can be opened or closed regulated by means of a control valve 8 connected thereto. The respective connection lines 7 are in each case combined in a collecting line 9 and connected to a dehydrogenation reactor 10 or a hydrogenation reactor 11. The dehydrogenation reactor 10 is also referred to as a discharge unit. The hydrogenation reactor 11 is also referred to as a loading unit. About feed pumps 12 hydrogen carrier medium along the manifolds 9 is promoted. In the reactors 10, 11 dehydrogenated or hydrogenated hydrogen carrier medium is recycled via the manifold 9 of the storage device 1 and in particular the storage container 4. The filling / removal unit 5 serves this purpose.

The hydrogen gas released in the dehydrogenation reactor 10 is removed via a discharge line 13 for further utilization in a utilization unit 14, in particular a fuel cell. As a recovery unit 14 may for example also serve a gas engine and / or a turbine. The released hydrogen gas can also be used for chemical processes or as an energy source for other drives. The hydrogen gas required for the hydrogenation of hydrogen carrier material is in a hydrogen supply unit 15, in particular an electro lyseur, generated and fed via a feed line 16 to the hydrogenation reactor 11. The storage device 1 with the storage container 4 can be advantageously used in a system for loading and / or unloading of hydrogen carrier medium. The storage container 4 allows the flexible use of different streams, in particular of the hydrogen carrier medium with different degrees of hydrogenation h and / or hydrogen and various heat flows. Particularly advantageous is the coupling of exothermic reactions such as electrolysis and / or hydrogenation with endothermic reactions such as the power generation of hydrogen in a fuel cell and / or dehydrogenation. An intermediate storage of hydrogen gas in the storage container 4 is also advantageous. The storage device is suitable in particular for use in real systems which are supplied by regenerative energy, in particular solar energy and / or wind energy, which is only available in a fluctuating manner. Due to the fluctuating process conditions inevitably result in different degrees of hydrogenation of the hydrogen carrier medium. In addition, a continuous mode of operation, ie operation of the system at partial load or even at minimum load, unavoidable since energy absorbed within a relatively short period of time, ie converted into hydrogen gas and bound to the hydrogen carrier medium, or released, so released from the hydrogen carrier medium and exuded , must become. The mode of operation is particularly necessary during a change between two process points of continuously operated systems for the hydrogenation and dehydrogenation of hydrogen carrier medium.

Additionally or alternatively, it is possible to specifically influence the dehydrogenation in the dehydrogenation reactor by changing the degree of hydrogenation h of the hydrogen carrier medium to be dehydrogenated. Thereby, the performance of the dehydrogenation reactor 10 can be adapted to the respective requirements. This can advantageously be achieved with the storage device by specifically removing hydrogen carrier medium from the storage container and feeding it to the dehydrogenation reactor 10. In particular, a change in the process parameters in the dehydrogenation reactor 10 is not required to achieve the desired power adjustment. Such a power adjustment is possible according to the prior art only by a comparatively complex change of process temperature, process pressure and / or supplied mass flow. The influence of the dehydrogenation reaction is easily possible. Particularly advantageous is the arrangement of a circulation flow with the storage device and the dehydrogenation reactor. In addition or as an alternative to the dehydrogenation reactor 10, the circulation flow with the storage device can also take place with the hydrogenation reactor 11. This makes it possible in a simplified manner to flow through the respective reactor 10, 11 with LOHC from the storage container 4 several times. As a result, the mass flow through the respective reactor 10, 11 can be increased. Under otherwise constant conditions, the size of the reactors 10, 11 can be reduced, wherein the same conversions, ie the same hydrogenation and dehydrogenation degrees can be achieved. By reducing the size of the reactors reduces the production engineering effort and the cost of materials. The cost is reduced.

A circulation flow can also be integrated in the storage tank 4 itself. As a result, in particular a heat integration within the storage container 4 is possible in order to use, for example, waste heat from an exothermic hydrogenation reaction within the storage container. The storage tank 4 can be designed and used as a heat storage and / or heat exchanger. For example, it is possible to remove heat from the hydrogenation reactor 11 to the storage tank in order to cool the hydrogenation reactor 11.

A cooling circuit, in particular using LOHC, in particular a heat transfer oil known by the trade name "Marlotherm SH", can be integrated into the storage tank LOHC and / or the heat transfer medium can be circulated in the storage tank LOHC in In particular, only a single LOHC cycle is required, and a secondary circuit for the heat transfer medium is dispensable, which means that such a system can be designed to be of a smaller construction Cost advantages and a reduced effort in the operation of such systems.

It is possible to integrate a separate, in particular external heating and / or cooling circuit in the storage container to selectively supply or remove process heat. An external one

Heating and / or cooling circuit can be an electric heater, a gas burner, in particular operated with natural gas or hydrogen gas, a building heating, a hot water supply and / or air conditioning include.

This applies correspondingly for influencing the hydrogenation reaction in the hydrogenation reactor 11.

The system 2 has, in particular, a central control unit 17, which is in particular in signal communication with the storage device 1, with the filling / removal unit 5, the control valves 8, the feed pumps 12 and / or the reactors 10, 11. The signal connection can be wired or wireless. By way of example, a wired signal connection 18 in FIG. 2 is shown by the control unit 17 to the hydrogenation reactor 11. In an analogous manner, the other signal connections exist.

The operation of Appendix 2 is explained in more detail below. In the storage container 4 of the storage device 1, hydrogen carrier medium is stored in a plurality of layers of different degrees of hydrogenation h. In energy surplus, so in particular in wind and / or sunny days, and / or if electrical energy is available on favorable terms in the energy market, electrical energy is fed into the hydrogen supply unit 15 to split water. Hydrogen gas is supplied via the supply line 16 to the hydrogenation reactor 11. For the hydrogenation required hydrogen carrier medium is pumped via the manifold 9 from the feed pump 12 from the storage tank 4 into the hydrogenation reactor 11. In this case, hydrogen carrier medium having the desired degree of hydrogenation h is withdrawn via targeted control of one of the control valves 8 at the respectively associated filling / removal opening of the storage container 4. Hydrogenation medium in the hydrogenation reactor 11 is preferably taken from hydrogen carrier medium having a comparatively low degree of hydrogenation h, in particular h <50%, in particular h <40%, in particular h <30%, in particular h <20%.

Subsequently, in the hydrogenation reactor 11, the hydrogenation of the hydrogen carrier medium takes place with a first, comparatively reduced degree of hydrogenation hi. After the hydrogenation, the hydrogenated, ie laden, hydrogen carrier medium is returned to the storage container 4 via the collecting line 9. After hydrogenation, the hydrogen carrier has a second degree of hydrogenation h ₂ , which is greater than the first degree of hydrogenation hi before hydrogenation. The hydrogen carrier medium, which is at least partially hydrogenated, is stored in the storage container 4 in a layer which is arranged above the layer from which the hydrogenation medium intended for the hydrogenation has been taken off above.

Correspondingly, conversely, the dehydrogenation, ie the release of hydrogen gas from at least partially hydrogenated, hydrogen carrier medium takes place.

Hereinafter, a second embodiment of the invention will be described with reference to FIGS. 3 and 4. Structurally identical parts are given the same reference numerals as in the first embodiment, to the description of which reference is hereby made. Structurally different but functionally similar parts receive the same reference numerals with a following a. In the storage device la, the two filling / removal units 5a each have a riser 19 for filling or removal of hydrogen carrier medium from the storage container 4. The riser 19 for filling the storage container 4 is sealed to the bottom wall guided in the storage container 4. The riser 19 extends within the storage container 4 substantially parallel to the longitudinal axis 3. The riser 19 extends from the bottom member over a majority of the height of the storage container 4. The length of the riser 19 is at least 50% of the height of the storage container 4 along the longitudinal axis. 3 , in particular at least 60%, in particular at least

70%, in particular at least 80%, in particular at least 90%, in particular at least 95%. The riser 19 is arranged at a distance from the top wall of the storage container 4. It is conceivable to attach the riser 19 to the top wall of the storage container 4.

The riser 19 for removing the hydrogen carrier medium from the storage container 4 is correspondingly opposite sealed out through the top wall of the storage container 4. The two risers 19 are substantially identical and differ only in their arrangement in the storage container 4. The risers 19 are each arranged vertically adjustable on the storage container 4. The height adjustment is symbolized by the double arrow 29 in Fig. 3. In principle, it is conceivable to use both risers 19 either for filling or for removal or for handling and removal of hydrogen carrier medium. It is also conceivable to provide only one riser 19, which is used for filling and removal of hydrogen carrier medium. A second riser is then unnecessary.

The risers 19 are each arranged eccentrically to the longitudinal axis 3 within the storage container 4. Relative to the longitudinal axis 3, the riser 19 are arranged diametrically opposite each other. The riser conduits 19 are in particular arranged point-symmetrically relative to a center of the storage container 4. The center is arranged on the longitudinal axis 3 centrally between the cover element and the bottom element. The risers 19 may also be arranged asymmetrically with respect to the longitudinal axis 3.

It is also possible to provide more than two riser lines, which are arranged in particular on a circular path and / or a polygonal line around the longitudinal axis 3. In particular, the riser lines are arranged along this circumferential line equally spaced from each other.

In addition or as an alternative to the different riser conduits 19, a plurality of risers may also be provided for removal or filling of the storage container, the risers each protruding into the storage container 4 at different distances, so that the filling / removal openings at different height positions along the Longitudinal axis 3 are arranged within the storage container 4. In particular, the removal of hydrogen carrier medium from the storage container 4 is advantageous via a displaceable riser 19.

Between the riser conduits 19 and in particular in a central region, which extends in particular cylindrically around the longitudinal axis 3 of the storage container 4, a calming region is provided. In the calming region, according to the exemplary embodiment shown, a first calming element in the form of a perforated tube 20 is provided as a permeable calming body. Further calming elements are designed in the form of baffles 21. The baffles 21 are attached directly to the risers 19. The baffles 21 extend from the riser 19 substantially radially. The guide plates 21 are welded in particular to the riser 19. It is also conceivable for the guide plates 21 to be pressed, screwed and / or plugged onto the riser. The filling / removal elements 6 in the form of the filling / removal openings are arranged in particular along the longitudinal axis 3 centrally between two baffles 21. In order to improve the flow conditions when the hydrogen carrier medium emerges from the riser 19 or when sucking in hydrogen carrier medium into the riser 19, the guide plates 21 in the region of the filling / removal

Openings 6 funnel-shaped. The filling / removal openings 6 are designed to be closed. For this purpose, for example, flaps can be provided at the filling / removal openings 6. The closeability of the filling / removal openings 6 allows targeted activation or use of the relevant openings. In particular, it can be ruled out that, in the case of a storage container 4 which is not completely filled, gas is sucked in via the openings 6 arranged above the filling level. It is ensured that only the filling / removal openings 6 arranged within the hydrogen carrier medium are used to remove hydrogen carrier medium from the storage container 4. The design of the riser 19 with the filling / removal elements 6 in the form of the filling / removal openings is shown schematically in Fig. 4. The baffles 21 serve to calm during the outflow of supplied hydrogen carrier medium into the storage tank 4 or during the inflow of abzuführendem hydrogen carrier medium from the storage tank 4 in the riser 19. Along the riser 19 each have several filling / removal openings are provided directly are designed as through holes in the tubular web line 19. Through the filling / removal openings, the filling and / or removal of hydrogen carrier medium is easily possible. The filling / removal openings are arranged along the riser 19 spaced from each other.

The risers 19 are in a direction parallel to the longitudinal axis 3 in the storage tank 4 on or out of the storage container 4 extendable. This makes it possible to adjust the height position of the To change filling / discharge openings 6 in the storage container 4 to adjust the removal of hydrogen carrier medium of a certain degree of hydrogenation. At the filling / removal openings 6 switchable flaps and / or valves may be provided to allow a targeted removal via activatable filling / removal openings 6.

A flow of the hydrogen carrier medium is indicated by the flow arrows. Feed hydrogen carrier medium will flow via the filling / removal element 6 in the storage container 4, ie escape at the location in the storage container 4, is stored on the hydrogen storage medium of similar density in the substantial. The outflow of the hydrogen carrier medium from the riser 19 takes place essentially automatically.

In the following, a third embodiment of the invention will be described with reference to FIG. Structurally identical parts are given the same reference numerals as in the first two embodiments, to the description of which reference is hereby made. Constructively different, but functionally similar parts receive the same reference numerals with a following b.

The storage device 1b has three storage areas 22, which are arranged one above the other along the longitudinal axis 3 of the storage container 4. The memory areas 22 are essentially identical. Each two adjacent storage areas 22 are separated from each other by a substantially horizontally oriented separating element 23.

The separating element 23 is designed in a particularly uncomplicated design as a plate which is fixed to an inner side of the storage container 4. Because in this embodiment, the interior of the storage container 4 would be separated into two partial interiors. The plate is impermeable to the hydrogen carrier medium.

Alternatively, the separating element for the hydrogen carrier medium can also be made permeable. This can be done, for example, by providing a comparatively rigid plate which has passage openings, for example in the form of a perforation. This results in a transition of the hydrogen carrier medium, in particular LOHC, from the one part Interior in the other part-interior of the storage container 4 allows. In this case, the separating element 23 is also a calming element.

The separating element 23 can be variably arranged along the longitudinal axis 3. This makes it possible to adjust the partial volumes of the partial interiors targeted. The partial inner spaces correspond to the storage areas 22. In particular, it is also conceivable to provide more than one separating element in order to create a plurality of storage areas 22.

The separating element can also be designed in the form of a membrane, which can be made flexible. Depending on an internal pressure in the storage container 4, the volumes of the storage areas can be adjusted as a function of pressure, for example in the case of a hydraulic bubble store.

It is also conceivable to provide a single, all storage areas supplying riser 19. In order to enable a targeted removal or targeted filling of hydrogen carrier medium in one of the storage areas 22, in particular switchable flaps are provided on the filling / removal elements 6.

The separate storage areas 22 serve to store the hydrogen carrier medium in a defined hydrogenation range. According to the exemplary embodiment shown, hydrogen carrier medium having a comparatively reduced degree of hydrogenation h is stored in the lower storage region 22, the hydrogenation degree h being in particular less than 30%. Hydrogen carrier medium having a comparatively high degree of hydrogenation h is stored in the storage region 22 arranged at the top, in particular: h> 70%. In the storage area 22 arranged therebetween, hydrogen carrier medium with approximately average hydrogenation degree h, for example between 30% and 70%, is stored. The limits of the hydrogenation degree ranges of the individual storage areas 22 can also be set differently. It is also conceivable that the limits of the hydrogenation degree ranges of the individual storage areas 22 overlap. Each storage area 22 has risers 19 for filling and withdrawing hydrogen carrier medium from one of the storage areas 22. For this purpose, the riser 19 are analogous to the filling / removal unit 5a executed. The storage container 4 additionally has a heat exchanger 24 which serves to supply and / or remove heat from the hydrogen carrier medium stored in the storage container 4. Due to the removal of heat from the storage container 4, the layer formation is promoted because of the reduced molecular movement at the reduced temperature. Stratification is advantageous for layered storage. In particular, hydrogen carrier medium, which is conducted through the heat exchanger 24 in the storage container 4, can be dispensed by means of a further, not-shown, external heat exchanger and used, for example, for heating the building.

The heat exchanger 24 can also be used in an undivided storage container 4 according to the first or second embodiment.

Hereinafter, a fourth embodiment of the invention will be described with reference to FIG. Structurally identical parts receive the same reference numerals as in the first three embodiments, the description of which reference is hereby made. Structurally different, but functionally similar parts receive the same reference numerals with a c.

The memory device 1 c has a plurality of memory areas 22. Each storage area 22 has separate filling / removal elements 6 in the form of inlet and outlet openings. At the inlet / outlet openings each control valves 8 are provided. It is conceivable that rise in the extension of the inlet / outlet openings within the storage tank risers 19 connect, which are not shown for purposes of illustration in Fig. 6.

Each memory area 22 is associated with a density monitoring unit 25 according to the exemplary embodiment shown. The density monitoring unit 25 has a density sensor, which is arranged in each case in the region of the bottom, in particular in the lower region, of the respective storage region 22. The density sensors of the density monitoring units 25 are according to The embodiment shown in each case designed as swing forks. It is also conceivable to provide for each storage area 22 and / or for the storage container 4 a plurality of spaced-apart along the longitudinal axis 3 spaced from each other density sensors of a density monitoring unit 25. The density sensors of the density monitoring units 25 are integrated on an outer cylinder jacket wall of the storage container 4.

For the density measurement, radiometric measuring principles, sensors based on ultrasound, flexural vibrators, vibration sensors or measurements based on the buoyancy force are possible. In principle, it is also conceivable to weigh the filled storage container on a weighing device. By weighing the filled storage container, an average density of the hydrogen carrier material can be determined.

The determination of the degree of hydrogenation can also be carried out by optical methods, in particular by means of a refractometer, since the change in the degree of hydrogenation causes a change in the refractive index of the water carrier medium.

The storage container 4 further has a fill level monitoring unit 26 with a fill level sensor 27, for example in the form of a radar probe for measuring the transit time of a radar signal which is radiated by the fill level sensor 27 and detects the signal reflected by the liquid surface. For this purpose, the filling level monitoring unit 26 has measuring tubes 28 which are each connected to a storage area 22 of the storage container 4. The execution of the level monitoring unit 26 with a radar probe, a continuous level monitoring is possible. The level monitoring can also be done by means of a tuning fork. Advantageously, a tuning fork serves both to monitor the density and to monitor the level of the hydrogen carrier medium in the storage container 4. In this case, the level monitoring unit 26 is integrated into the density monitoring unit 25.

For the determination of the level, physical measuring methods such as ultrasound, in particular in the form of a transit time measurement, guided microwaves, capacitive measuring principles, hydrostatic measuring principles, in particular in the form of a pressure measurement or by buoyancy, or for example by optical measuring method into consideration.

In the following, a second embodiment of a system will be described with reference to FIG. Structurally identical parts are given the same reference numerals as in the first embodiment, the description of which reference is hereby made. Structurally different, but functionally similar parts receive the same reference numerals with a d followed. The system 2d essentially corresponds to the system 2 according to the first embodiment. The only difference is that the feed pumps 12 along the manifolds 9 must be suitable for bidirectional fluid flow. For loading and unloading the hydrogen medium only a single, combined reactor 29 is provided. In the reactor 29, both the loading and the unloading is possible.

Hereinafter, a fifth embodiment of the invention will be described with reference to FIG. Structurally identical parts receive the same reference numerals as in the previous embodiments, the description of which reference is hereby made. Structurally different, but functionally similar parts receive the same reference numerals with a trailing e.

The storage device le has a height-adjustable riser 19e. Along the longitudinal axis 3 a plurality of filling / removal openings 6 are provided. The storage container 4 is not completely filled. A part of the filling / removal openings 6 is arranged above the filling level 30. In order to avoid that these exposed filling / removal openings 6 unintentionally suck in an actuation of the feed pump 12 medium, such as gas, which is not to be promoted in the hydrogenation reactor 11 or dehydrogenation reactor 10, a closure member 31 is disposed within the riser 19e , The closure element 31 has a similar geometry as the riser 19e itself and the closure member 31 extends along the longitudinal axis 3 and allows according to the embodiment shown, the closure of three filling / removal openings 6. Each an upper side and a lower side, the closure element 31 is arranged sealed in the interior of the riser 19. For sealing serve sealing elements 32, for example, O-rings.

It is also conceivable to dispense with the closure element 31 in the form of the piston and, in particular, to provide only the lower sealing element 32. It is essential that the filling / removal openings 6 arranged above the filling level 30 are sealed. Advantageously, the closure element 31 and in particular the lower sealing element 32 along the longitudinal axis 3 separately, ie relative to the riser 19e, displaced.

Claims

claims

1. Storage device for hydrogen carrier medium comprising

a. a storage container (4) having a longitudinal axis (3) for layered storage of the hydrogen carrier medium as a function of its degree of hydrogenation (h), b. a filling / removal unit (5; 5a; 5b; 5) connected to the storage container (4);

5c) for filling and / or removal of hydrogen carrier medium.

2. Storage device according to claim 1, characterized in that the BefüU- tapping unit (5; 5a; 5b; 5c) has at least one filling / removal element (6).

3. Storage device according to one of the preceding claims, characterized in that the filling / removal unit (5a; 5b; 5c) has a riser (19) on which in particular a filling / removal element (6) is arranged.

4. Storage device according to claim 3, characterized in that the riser (19) with the at least one filling / removal element (6) within the storage container (4) is arranged, wherein the riser (19) in particular relative to the storage container (4 ) is changeable can be arranged.

5. Storage device according to one of the preceding claims, characterized in that the filling / removal unit (5; 5a; 5b; 5c) has a plurality of filling / removal elements (6), which in particular spaced along the longitudinal axis (3) are arranged.

6. Storage device according to one of the preceding claims, characterized in that the filling / removal unit (5; 5a; 5b; 5c) has at least one control valve (8), in particular associated with a filling / removal element (6) is.

7. Storage device according to one of the preceding claims, characterized by a heat exchanger (24) for transferring heat from or to the hydrogen carrier medium

8. Storage device according to one of the preceding claims, characterized by a control unit (17) for the controlled filling and / or removal of hydrogen carrier medium.

9. Storage device according to one of the preceding claims, characterized by a level monitoring unit (26), in particular at least one level sensor (27).

10. Storage device according to one of the preceding claims, characterized by a condition monitoring unit (25) which has in particular at least one state sensor, wherein in particular a plurality of state sensors are provided, which are arranged along the longitudinal axis (3) spaced from each other.

11. Storage device according to one of the preceding claims, characterized in that the storage container (4) a plurality of separating elements (23) separated from each other

Memory areas (22), wherein in particular each memory area (22) is associated with at least one filling / removal element (6).

12. Storage device according to one of the preceding claims, characterized by at least one calming element for calming the hydrogen carrier medium in the

Storage tank (4), wherein the calming element is designed in particular as a baffle (21) and / or as a permeable sedative body (20).

13. system for loading and / or unloading of hydrogen comprising

a. a memory device (1; la; lb; lc) according to one of the preceding claims, b. a hydrogenation reactor (11) connected to the storage device (1; la; lb; lc) and / or a dehydrogenation reactor (10) connected to the storage device (1;

14. A method for storing a hydrogen carrier medium, comprising the method steps of providing a memory device according to one of claims 1 to 12, Storing the hydrogen carrier medium as a function of its degree of hydrogenation (h).

15. The method according to claim 14, characterized by filling the storage container (4) with hydrogen carrier medium and / or removal of hydrogen carrier medium from the storage container (4) by means of the filling / removal unit (5; 5a; 5b; 5c), wherein the

Filling and / or removal into or from selectively selected hydrogen carrier medium layers, wherein in particular the degree of hydrogenation of the hydrogen carrier medium stored in the storage container is determined and / or monitored by means of a condition monitoring unit, and / or wherein the hydrogen carrier medium is filled in a controlled manner by means of a control unit and / or or is taken.