METHOD FOR PROVIDING HYDROGEN GAS, DEHYDROGENATION REACTOR AND TRANSPORT CONTAINER

Description

[0001] The invention relates to a method for providing hydrogen gas.

[0002] EP 1 475 349 A2 discloses a method for storing and releasing hydrogen gas from a hydrogen carrier material. Similar methods are known from DE 10 2014 006 430 A1, US 7,485,161 B2, JP 2002-134141 A, WO 2015 / 061 215 A2, US 2013 / 142726 A1, and WO 2016 / 078 949 A1.

[0003] The invention is based on the object of improving the release of hydrogen gas in such a way that hydrogen gas can be provided by means of a robust and economically feasible process with an increased quality, in particular purity.

[0004] This object is achieved by a process having the features specified in claim 1. The core of the invention consists in advantageously combining the process steps required for providing hydrogen gas in such a way that hydrogen of increased purity can be released under robust and economical conditions from a hydrogen carrier material, in particular an organic liquid, also known as a liquid organic hydrogen carrier (LOHC). According to the invention, it has been found that preheating the at least partially hydrogenated hydrogen carrier material is energy-efficient for the overall process. Depending on the reaction conditions and the loading of the hydrogen carrier material, more or less complete discharge, i.e. dehydrogenation, is possible. In particular, the fed LOHC material is not completely hydrogenated. The degree of hydrogenation is typically between 50% and 100%, preferably between 80% and 95%.After dehydration, the degree of hydrogenation is, for example, between 0% and 50%, but can also be higher.

[0005] By purifying the released hydrogen gas, the quality, in particular the purity of the hydrogen gas, is improved. Cooling and conditioning the at least partially dehydrogenated hydrogen carrier material ensures increased safety during storage and handling of the hydrogen carrier material. The at least partially dehydrogenated hydrogen carrier material is cooled to a target temperature of less than 60°C, in particular less than 50°C, and in particular to approximately 40°C. At this temperature, safe handling and storage of the hydrogen carrier material, in particular the LOHC, is possible without danger. The safety risk is reduced. Conditioning comprises the removal of physically dissolved residual hydrogen gas from the hydrogen carrier material. The process according to the invention is economically viable, especially in small-scale plants. Such small-scale plants can be operated in a decentralized manner.In the following, a small plant is understood to mean a transportable plant, particularly one within a transport container. Such a small plant has a maximum output of 5 MW. The small plant is supplied with hydrogen carrier material by truck, and not by ship, train, or pipeline. Hydrogen carrier material can be transported by road, allowing for flexible location and timing. The process is particularly feasible using a dehydrogenation reactor, which can be arranged in a conventional transport container. Using the transport container, the dehydrogenation reactor can be transported flexibly and easily to a decentralized location and operated there.

[0006] Preheating according to claim 2 enables an efficient and direct supply of heat. It is advantageous if the reactant, i.e., the at least partially hydrogenated hydrogen carrier material, is preheated by means of an exiting product stream from the dehydrogenation. The product stream from the dehydrogenation comprises the released hydrogen gas and the at least partially dehydrogenated hydrogen carrier material. The latent heat present in the product stream is directly used to preheat the hydrogen carrier material. The efficiency of the process is increased. The released hydrogen gas and the at least partially dehydrogenated hydrogen carrier material are available at the reaction temperature, which is approximately 300 °C.By bringing the reactant stream into direct contact with at least one of the reactant streams, particularly in the form of a countercurrent scrubber or a spray condenser, not only efficient heat recovery is possible to increase efficiency, but also the separation of impurities from the released hydrogen gas and / or the at least partially dehydrogenated hydrogen carrier material. Preheating can be achieved by direct or indirect contact with the product streams. Preheating can be achieved by contact with the released hydrogen gas, the at least partially dehydrogenated hydrogen carrier material, or a mixture of both.

[0007] The release of hydrogen gas according to claim 3 is particularly advantageous. The reaction conditions favor efficient release.

[0008] The purification of the released hydrogen gas according to claim 4 is effective. This makes it possible to ensure a required purity of up to 99.999% for the hydrogen gas, which is particularly required for the use of hydrogen gas in a fuel cell or for the food industry. According to the invention, it was recognized that the purification can be varied depending on the subsequent intended use of the released hydrogen gas. In particular, methane impurities are comparatively unproblematic for the use of hydrogen gas in fuel cells. In contrast, carbon monoxide impurities must be avoided when using hydrogen gas in a fuel cell. Hydrocarbon impurities are relatively unproblematic when using hydrogen gas as a fuel gas, although hydrocarbon impurities are unacceptable in the food industry.The contaminants to be separated can be in solid, liquid, or gaseous form. For example, a contaminant can be present in the form of aerosol droplets in the hydrogen gas.

[0009] Separation in at least one separation stage enables the targeted separation of contaminants depending on their physical state. In particular, this makes it possible to provide a separate separation stage for each physical state of a contaminant, i.e., solid, liquid, or gaseous. With knowledge of the contaminants present, efficient purification of the hydrogen gas is possible. In particular, the separation takes place in multiple stages, i.e., with several separation stages, particularly those connected in series. A solid contaminant can be, for example, coke, i.e., a fuel with a high carbon content and a high specific surface area. A liquid contaminant can be in the form of LOHC and / or aerosol droplets. Gaseous contaminants can be in the form of carbon monoxide, methane, carbon dioxide, and / or water vapor, as well as in the form of volatile hydrocarbons such as toluene or cyclohexane.

[0010] Increasing the pressure of the gas phase according to claim 5 enables an improvement in the overall efficiency of the process. The increased efficiency results from the fact that more usable product gas, i.e., hydrogen gas, is available per amount of material, i.e., LOHC, used. The higher the pressure during pressure swing adsorption, the higher the yield of usable product gas. It has proven particularly advantageous to increase the pressure of the released hydrogen gas. The pressure increase can be achieved as intermediate compression through ionic, thermal, and / or mechanical compression.

[0011] Separation processes according to claim 6 ensure advantageous purification. Adsorptive processes or conversion of the gaseous contaminants via chemical reactions are particularly suitable for separating gaseous contaminants.

[0012] In particular, it was found that adsorption processes, in particular a pressure swing adsorption process, can be carried out particularly efficiently at high gas pressures.

[0013] In pressure swing adsorption, gas is fed to a reactor, particularly a fixed-bed reactor, filled with the adsorbent at an elevated pressure of at least 5 bar, in particular at least 10 bar, and especially at least 15 bar. One or more components of the gas, the so-called heavy components, are adsorbed. At the reactor outlet, the so-called light component, which has not been adsorbed, can be removed in concentrated form. After the adsorbent is saturated, the adsorbed heavy component can be released, i.e., desorbed, by reducing the pressure and removed separately.

[0014] Additionally, adsorptive deposition can be carried out in the form of pressure swing adsorption and / or temperature swing adsorption. The temperature during possible temperature swing adsorption is typically less than 100 °C, in particular less than 60 °C, and in particular less than 30 °C. The purity of the hydrogen gas can thereby be improved. The regeneration of the adsorbent takes place at a temperature of at least 100 °C, in particular at least 150 °C, and in particular at least 200 °C. The hydrogen-containing gas mixture removed during the regeneration of the adsorbent can be subjected to thermal utilization, in particular combustion, to further increase the efficiency of the process.

[0015] A separation according to claim 7 enables the advantageous conversion of a gaseous contaminant using catalytically active materials installed in the product stream. It has been found that the reaction conditions present in the product stream correspond to those of a catalytic gas-phase reaction, such as the methanation of carbon monoxide. This enables particularly efficient post-conditioning of the hydrogen gas. A separate, additional reactor for conditioning the released hydrogen gas is unnecessary. In particular, the purification of the hydrogen gas can be provided as an integral process step in the provision of the hydrogen gas. The separation of liquid contaminants, such as aerosols, is efficiently possible in multi-stage separation processes.Using a coalescence filter, the droplet size of the aerosols can first be increased and then efficiently separated from the gaseous phase of the product stream by means of a subsequent lamella separation.

[0016] Controlled purification according to claim 8 ensures the provision of hydrogen gas with the required purity. The purification can be efficiently and variably adjusted. On the one hand, it is guaranteed that the hydrogen gas has the required purity. On the other hand, it is ensured that excessive purification, i.e., cleaning to a purity level that is not technically necessary, is avoided. Over-purification, i.e., cleaning beyond the required purity level, is avoided. The required cleaning effort is controllable. In particular, it is advantageous to continuously monitor the current purity level using suitable sensors and to regulate it using a control unit. A typical purity level for hydrogen gas can be 99.999%.

[0017] Cooling according to claim 9 is particularly efficient. In particular, in the event that cooling by direct or indirect contact with the product streams alone is not sufficient or not sufficiently rapid, an additional cooling unit can be provided.

[0018] Removing hydrogen gas, which is present in particular in physically dissolved form on the at least partially dehydrogenated hydrogen carrier material, according to claim 10 improves the storage conditions of the hydrogen carrier material. This can reduce the risk of an explosive hydrogen atmosphere in a storage tank for the at least partially dehydrogenated hydrogen carrier material. An explosive hydrogen atmosphere in the storage container can arise if hydrogen outgasses above the liquid phase during prolonged storage of the at least partially dehydrogenated hydrogen carrier material without sufficient ventilation. The physically dissolved hydrogen gas can be separated in one or more stages by separation. In a first stage, a distribution unit similar to a shower head can be used, which is connected to a stripping column or a spray tower.Additionally or alternatively, a purge gas, in particular an inert gas such as nitrogen or argon or compressed air, can be used to discharge hydrogen gas in a column. In addition or alternatively to a purge gas, a negative pressure, in particular a vacuum, can be applied to discharge the hydrogen gas. It is advantageous if the hydrogen content remaining in the hydrogen carrier material is between 0.1 and 10 ppm by weight. Even if hydrogen gas outgasses during longer-term storage of the hydrogen carrier material, the resulting hydrogen concentration in the storage vessel is lower than the explosion limit of hydrogen in air and / or air containing LOHC. The risk of an explosion due to outgassing hydrogen can also be reduced by designing a comparatively large air cushion in the storage vessel, in which a maximum permissible fill level is typically limited to 80% of the vessel volume.This ensures that the critical explosion limit is not reached even when hydrogen gas is released. Conditioning the hydrogen carrier material ensures its long-term, reliable storage.

[0019] It is also conceivable to provide a separation stage for impurities in the solid state, in particular as abrasion of the catalyst material.

[0020] A dehydrogenation reactor comprising a reactor housing, at least one catalyst support arranged in the reactor housing, on which a catalyst support with catalyst material is arranged, a heating unit for heating the at least one catalyst support, a distribution unit for uniformly distributing a feed stream of at least partially hydrogenated hydrogen support material to the at least one catalyst support, and at least one outlet opening for continuously removing hydrogen gas and at least partially dehydrogenated hydrogen support material from the dehydrogenation reactor, enables an advantageous implementation of the process. The advantages of the dehydrogenation reactor essentially correspond to the advantages of the process, to which reference is hereby made. It has been found that the catalyst material can advantageously be arranged in at least one catalyst support arranged in a reactor housing.A tube, a plate, or a combination thereof can serve as the catalyst support. The distribution unit can advantageously comprise capillaries, flow breakers, and / or distributor plates. At least one outlet opening enables the continuous removal of hydrogen gas and hydrogen carrier material. Two outlet openings can also be provided, whereby a coarse separation can be distinguished during removal into gaseous and liquid phases of the product streams. A phase separator, which serves in particular for the distributed supply of the at least partially dehydrogenated hydrogen carrier material, can comprise a built-in distribution unit that serves to generate large specific surface areas. The distribution unit can be designed as a stripping column, an extruder, a spray tower, or a combination of these units.

[0021] A heating unit with a jacket filled with liquid, steam, and / or gas ensures efficient heating. The heating unit promotes the highly endothermic dehydrogenation reaction in the dehydrogenation reactor.

[0022] The use of platinum, palladium, nickel, rhodium and / or ruthenium, each in a weight proportion of 0.1% to 10% based on the, in particular inert, catalyst support as catalyst material, enables efficient release of the hydrogen gas.

[0023] A catalyst support comprising aluminum oxide, silicon oxide, silicon carbide, and / or activated carbon enables advantageous attachment of the catalyst material. The catalyst support material promotes the highly endothermic dehydrogenation reaction in the dehydrogenation reactor. It is advantageous if the catalyst support material is an inert material. In addition, inert additional material, for example in the form of glass spheres, metal spheres, or metallic structures such as tubes, nets, or grids, can be attached to the holders inside or outside. The inert additional material serves, for example, to dilute the catalyst material and / or to hold the catalyst support material. For example, a structure is conceivable with a net of inert additional material on which glass spheres are provided for diluting the catalyst material, with catalyst material arranged on the glass spheres.For example, it is conceivable that the inert catalyst support material and the inert additive material are of the same type and, in particular, identical. In particular, the inert catalyst support material differs from the inert additive material by a metallic coating.

[0024] A transport container containing a dehydrogenation reactor enables flexible, location-independent and decentralized use of the process for providing hydrogen.

[0025] Further advantageous embodiments, additional features, and details of the invention will become apparent from the following description of exemplary embodiments with reference to the drawings. They show: Fig. 1 a schematic side view of a transport container with a dehydrogenation reactor, Fig. 2 an enlarged schematic side view of the dehydrogenation reactor in Fig. 1 , Fig. 3a Fig. 1 corresponding schematic view of a transport container with a dehydrogenation reactor according to a second example, Fig. 4 an enlarged schematic side view of the dehydrogenation reactor in Fig. 3 , Fig. 5 an enlarged schematic side view of a LOHC conditioning unit in Fig. 3 .

[0026] One in Fig. 1 The transport container 1 shown is known per se and can be easily transported by ship, truck, and / or railway wagon. The transport container 1 has standardized dimensions.

[0027] A dehydrogenation reactor 2 is arranged in the transport container 1 and is connected to an LOHC storage tank 3 via an LOHC supply line 4 and an LOHC discharge line 5. LOHC serves as the hydrogen carrier medium. The LOHC storage tank 3 is connected to an LOHC source 6 via a line 7. According to the illustrated embodiment, the LOHC storage tank 3 serves to store loaded LOHC, which is discharged, i.e., dehydrogenated, in the dehydrogenation reactor 2 by releasing hydrogen gas.

[0028] Additionally, a further storage container (not shown) can be provided, in which the hydrogen carrier medium discharged in the dehydrogenation reactor 2 is stored. This means that, in particular, two separate LOHC storage containers are provided, one for the loaded, i.e., high-energy LOHC, and one for the discharged, i.e., low-energy LOHC. The two storage containers can be arranged in the transport container 1 or outside the transport container 1.

[0029] For example, it is also possible for large LOHC storage tanks to be arranged outside of the transport container 1 in order to ensure a sufficient, long-term supply of LOHC. Smaller LOHC storage tanks can be provided within the transport container as buffer tanks to ensure the operation of the transport container even if the supply of LOHC medium from the storage tanks arranged outside the transport container 1 is not guaranteed, especially temporarily.

[0030] The LOHC source 6 can be an external source, such as a LOHC transport vehicle. Additionally or alternatively, the LOHC source 6 can also have a hydrogenation reactor, which serves for loading, i.e., for at least partially hydrogenating, LOHC as a hydrogen carrier material. For this purpose, at least partially unloaded LOHC is loaded with hydrogen gas in the hydrogenation reactor (not shown). The hydrogen gas can originate, for example, from electrolysis in an electrolyzer (not shown). The electrolyzer is powered, for example, with electricity from wind power and / or photovoltaic systems. The electrolyzer can also be supplied with power from a power grid, in particular a public grid.

[0031] The LOHC source 6 is connectable to the LOHC storage container 3, in particular via the line 7. The LOHC source 6 is arranged, in particular, outside the transport container 1. The line 7 can have a suitable interface to ensure uncomplicated connectivity to the LOHC source 6. The LOHC source 6 is arranged, in particular, in a stationary manner at a power generation site. It is also conceivable to integrate the LOHC source 6, at least partially, in particular in the form of the hydrogenation reactor and / or the electrolyzer, into the transport container 1.

[0032] The LOHC supply line 4 serves to supply at least partially hydrogenated LOHC from the LOHC storage tank 3 into the dehydrogenation reactor 2. The LOHC discharge line 5 serves to discharge at least partially dehydrogenated LOHC from the dehydrogenation reactor 2 into the LOHC storage tank 3.

[0033] The dehydrogenation reactor 2 is connected to a hydrogen consumer 8 via a hydrogen line 9. The hydrogen consumer 8 is designed as a fuel cell and enables the hydrogen generated in the dehydrogenation reactor 2 to be converted into electricity. Other uses of hydrogen are also possible. It is also conceivable to integrate the hydrogen consumer 8 in the form of a fuel cell into the transport container 1 in order to provide electrical power for a power consumer and / or a power grid for feeding into it. In addition to or as an alternative to the use of hydrogen by the fuel cell, thermal utilization of the hydrogen and / or the provision of the hydrogen for material use, particularly in the food industry, are conceivable.

[0034] The following is based on the Fig. 2 The dehydrogenation reactor 2 is explained in more detail. The dehydrogenation reactor 2 has a reactor housing 10 in which several catalyst supports 11 are arranged. A catalyst support with catalyst material 12 is arranged on each catalyst support 11. According to the embodiment shown, the catalyst supports 11 are arranged horizontally, i.e., essentially horizontally. It is also conceivable to arrange the catalyst supports 11 inclined relative to the horizontal and, in particular, vertically. The catalyst supports 11 with the catalyst material 12 form a fixed catalyst bed. The dehydrogenation reactor 2 can be operated in a single stage.

[0035] A heating unit 13 is provided on each of the catalyst supports 11 to enable direct and efficient heating of the catalyst material 12. The heating unit 13 is, in particular, integrated into the catalyst support 11. The heating unit 13 is, in particular, designed as a jacket filled with liquid, vapor, and / or gas and / or as an electric heater.

[0036] An LOHC distribution unit 14 is connected to the LOHC supply line 4 in the reactor housing 10. The LOHC distribution unit 14 is essentially designed in the form of a shower head and enables a distributed supply of the LOHC 15 to the catalyst material 12 on the catalyst supports 11. Instead of the shower head, the LOHC distribution unit 14 can also be designed as a capillary plate, a flow breaker, and / or a distributor plate.

[0037] Additionally, the shower head can also be designed as a surface enlargement unit 30. The surface enlargement unit 30 enables an advantageous surface enlargement of the LOHC 15 as it is fed onto the catalyst holders 11. This favors the subsequent dehydrogenation reaction, since the reactant, i.e., the loaded LOHC 15, has a comparatively large surface area to react with the catalyst material 12 arranged in the catalyst holders 11. The unit for surface enlargement of the LOHC can also be provided separately and, in particular, in a design different from a shower head.

[0038] The dehydrogenation reactor 2 has an LOHC outlet 16 and a hydrogen gas outlet 17. By means of a collecting device 18, at least partially dehydrogenated LOHC 15 is removed from the dehydrogenation reactor 2 via the LOHC outlet 16 and the LOHC discharge line 5. The collecting device 18 can be a funnel-shaped collecting basin with a discharge line. Other designs of the collecting device 18 are also conceivable.

[0039] In the area of the hydrogen gas outlet opening 17, an extraction device 19 can be provided to promote the exit of the hydrogen gas from the dehydrogenation reactor 2. The dehydrogenation reaction can be accelerated by means of the extraction device 19. However, the extraction device can also be omitted. Particularly in the case where the release takes place at a process pressure of more than 1 bar, the released hydrogen gas can be extracted from the dehydrogenation reactor 2 without additional pressure delivery units, such as a compressor. It is then advantageous to adapt the pressure of the hydrogen gas to any necessary downstream purification steps for the hydrogen gas.

[0040] The function of the dehydrogenation reactor 2 according to a first process is explained in more detail below. A reactant stream with at least partially hydrogenated LOHC as the hydrogen carrier medium is fed from the LOHC storage tank 3 to the dehydrogenation reactor 2 via the LOHC feed line 4. Before feeding, the LOHC reactant is preheated with at least partially dehydrogenated hydrogen carrier material, i.e., LOHC product, from the dehydrogenation reactor 2. For this purpose, the LOHC feed line 4 and the LOHC discharge line 5 can be combined at least in sections to enable direct contact between the LOHC reactant and the LOHC product, particularly in a countercurrent process.

[0041] The dehydrogenation of the at least partially loaded hydrogen carrier material takes place in the dehydrogenation reactor 2 at a reaction pressure of 2.5 bar and a reaction temperature of 310 °C. The released hydrogen gas is purified and cooled by a purification unit (not shown). In particular, a catalytic conversion of carbon monoxide gas to methane takes place in a coated wire mesh and in a fixed-bed adsorption. The released hydrogen gas is fed to the fuel cell 8 for electricity generation via the hydrogen gas outlet 17 and the hydrogen line 9.

[0042] The LOHC product, which has already been used to preheat the LOHC reactant, is cooled in a separate cooler (not shown) depending on the residual heat and then fed to a conditioning unit (not shown) in the form of a stripping column in order to remove residual hydrogen, which is in particular physically bound.

[0043] According to a further embodiment of the process according to the invention, hydrogen gas can be provided for direct combustion. For this purpose, LOHC reactant is conveyed into the dehydrogenation reactor 2. Before being fed in, the LOHC product, together with the hydrogen gas entrained therein, serves to preheat the LOHC reactant through direct contact. In this case, hydrogen and LOHC reactant are discharged from the dehydrogenation reactor 2 via a common outlet opening and discharge line.

[0044] The dehydrogenation reaction takes place at a pressure of 2.5 bar and a temperature of 310 °C. After preheating the LOHC reactant in a phase separator, the product stream is roughly separated into a predominantly hydrogen-containing, gaseous product stream and a predominantly LOHC-containing, liquid product stream. The liquid LOHC product is freed of residual hydrogen using a cooler and vacuum degassing. The gaseous hydrogen stream eliminates the need for further conditioning and can be used directly for combustion.

[0045] According to a further embodiment of the process, hydrogen gas can be used for the food industry. For this purpose, LOHC reactant is pumped into dehydrogenation reactor 2. It is first preheated against LOHC product. The dehydrogenation reaction takes place at 2.5 bar and 310 °C. The released hydrogen gas is purified by catalytic conversion of carbon monoxide to methane in a coated wire mesh and subsequent separation of liquid components in a scrubbing column and using pressure swing adsorption. Compared to fixed-bed adsorption, pressure swing adsorption has the advantage that the product gas is free of carbon monoxide (CO) and methane (CH 4 ). After use, the LOHC product is freed of residual hydrogen using a cooler and a stripping column to preheat the LOHC reactant.

[0046] The process according to the invention for providing hydrogen gas can be used for further purposes, such as the use of hydrogen as a protective gas, the integration of further purification stages in the hydrogen product stream and / or hydrogen separation in the product stream of the hydrogen carrier material.

[0047] In the following, with reference to Fig. 3 bis 5 A second embodiment of the invention is described. 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 are given the same reference numerals with an a suffix.

[0048] Units for four basic process steps are arranged in the transport container 1a, namely a LOHC pretreatment unit 20, a dehydrogenation reactor 2a, a hydrogen conditioning unit 21 and a LOHC conditioning unit 22.

[0049] Loaded LOHC 15 is fed via a line from a LOHC storage container 3a, possibly located outside the transport container 1a, into the pretreatment unit 20. After pretreatment, the hydrogen is released in the dehydrogenation reactor 2a. If necessary, the liquid and gaseous phases are separated at the outlet of the dehydrogenation reactor 2a, with the liquid phase being fed directly into the LOHC conditioning unit 22. The gaseous phase is post-treated in the hydrogen conditioning unit 21 so that residual liquid components are separated and fed into the LOHC conditioning unit 22. The hydrogen 23 produced is fed via a line to the external hydrogen consumer 8. In addition to the hydrogen consumer 8, a hydrogen storage unit can be provided.

[0050] The hydrogen 23 has a quality adapted to the hydrogen consumer 8, wherein in particular the hydrogen conditioning unit 21 is designed in such a way, in particular in several stages, that the quality is ensured with the necessary pressure level depending on the application.

[0051] In the LOHC conditioning unit 22, the LOHC is post-conditioned so that the discharged LOHC 24 can be stored in a second LOHC storage container 25, possibly located outside, without any special requirements for inerting or handling due to the residual hydrogen.

[0052] Optionally, part or all of the LOHC stream from the LOHC conditioning unit 22 is used for the LOHC pretreatment unit 20 to accomplish the pretreatment of the loaded LOHC 15 by heat exchange and / or mass transfer in direct contact.

[0053] Loaded LOHC 15, preconditioned in the LOHC pretreatment unit 20, is fed into the dehydrogenation reactor 2a through a distribution unit 14a, which, according to the illustrated embodiment, is designed as a capillary plate. The distribution unit 14a can, in principle, also be constructed in the form of a showerhead or various other designs. It is essential that the supplied, loaded LOHC 15 is evenly distributed among the catalyst supports arranged in the housing of the dehydrogenation reactor 2a. It is also essential that dead volumes are avoided. The catalyst supports 11 can be tubes, plates, or similar supports, which can be completely or partially filled with catalyst on an inert support material and additionally with other, non-catalyst-containing support materials in order to adapt the reaction conditions with regard to residence time distribution.The catalyst supports 11 are heated by an external heating unit 13a to ensure optimal heat input for the highly endothermic reaction. This can be achieved via heat transfer media or other methods.

[0054] At least one, but typically two LOHC streams leave the dehydrogenation reactor 2a for a division of a predominantly gaseous phase into the hydrogen conditioning unit 21 and a liquid phase into the LOHC conditioning unit 22.

[0055] The Fig. 5 The LOHC conditioning unit 22 shown enables advantageous handling of the LOHC, which can be particularly highly viscous. The LOHC conditioning unit 22 guarantees uncomplicated and robust separation of dissolved hydrogen.

[0056] LOHC 15 from the dehydrogenation reactor 2a or the hydrogen conditioning unit 21 is fed into the LOHC conditioning unit 22 for LOHC conditioning. Within the LOHC conditioning unit 22, a high surface area is generated by a shower head 26 as a distribution unit or a distribution device with a similar function. By increasing the surface area of the particularly highly viscous LOHC, the separation of the hydrogen gas is promoted. The dehydrogenation can be improved and simplified.

[0057] A packing, bed, or similar device ensures a high level of surface renewal in a subsequent stripping unit 27. A stripping gas such as air or nitrogen is supplied from an externally arranged stripping gas reservoir 28 and typically passed through the stripping unit 27 in countercurrent to the LOHC. The hydrogen-containing output stream can be fed to an external exhaust gas purification system 29, ventilation, and / or combustion. As an alternative to introducing a gas from the stripping gas reservoir 28, a vacuum can be applied, particularly in the exhaust gas purification area 29, to achieve a qualitatively similar effect.

[0058] The LOHC 24, freed from residual hydrogen and thus ready for storage, leaves the LOHC conditioning unit 22 via a separate outlet to the second LOHC storage tank 25.

Claims

1. Method for providing hydrogen gas comprising the process steps - pre-heating of an at least partially hydrogenated hydrogen carrier material, - release of hydrogen gas by means of at least partial dehydrogenation of the hydrogen carrier material, - purification of the released hydrogen gas, - cooling of the at least partially dehydrogenated hydrogen carrier material to a target temperature of less than 60 °C and conditioning of the at least partially dehydrogenated hydrogen carrier material, wherein the conditioning includes the removal of physically dissolved residual hydrogen gas from the hydrogen carrier material.

2. Method according to claim 1, characterized in that the pre-heating of the hydrogen carrier material comprises a contacting with the released hydrogen gas and / or with the at least partially dehydrogenated hydrogen carrier material.

3. Method according to one of the preceding claims, characterized in that the release takes place at a process pressure of more than 1 bar, in particular between 2 bar and 10 bar, in particular between 2.5 bar and 5 bar, and / or at a process temperature of more than 200 °C, in particular between 250 °C and 350 °C, in particular between 270 °C and 310 °C.

4. Method according to one of the preceding claims, characterized in that the purification of the released hydrogen gas comprises the separation of at least one impurity, wherein the at least one impurity is present in solid, liquid or gaseous aggregate state, wherein in particular the separation into at least one separation stage is carried out, wherein in particular the at least one separation stage serves for separating an impurity in a specific aggregate state.

5. Method according to one of the preceding claims, characterized in that for purification of the released hydrogen gas, a pressure increase by ionic, thermal and / or mechanical compression is provided.

6. Method according to claim 4 or 5, characterized in that the separation shows at least one of the methods coalescence precipitation, cyclone separation, adsorption separation, counterflow washer or injection into a washing liquid, wherein the adsorption separation comprises in particular a pressure swing adsorption and / or a temperature change adsorption.

7. Method according to claims 4 to 6, characterized in that the separation comprises a catalytic conversion of the at least one impurity.

8. Method according to one of the preceding claims, characterized in that the purification takes place until a, in particular variably, adjustable degree of purity of the hydrogen gas is achieved.

9. Method according to one of the preceding claims, characterized in that the cooling takes place by means of an additional cooling unit.

10. Method according to one of the preceding claims, characterized in that after the conditioning of the hydrogen carrier material a residual portion of physically dissolved hydrogen gas in the at least partially dehydrogenated hydrogen carrier material is between 1 and 10 ppm by weight.