Hydrogen-production plant

Abstract

The invention relates to a hydrogen production plant (100, 200, 400), comprising at least one electrolyser stack (102, 202), at least one housing (104, 204, 404) having at least one first housing region (106, 206, 406) surrounding the at least one electrolyser stack (102, 202), and at least one inert gas generation device (108, 208) fluidically connected to the first housing region (106, 206, 406) and designed to provide an inert gas, in such a way that the first housing region (106, 206, 406) is filled with an inert gas mixture at least during an operating state of the at least one electrolyser stack (102, 202).

Description

[0001]

[0002] October 9, 2025

[0003] Hydrogen production plant

[0004] The invention relates to a hydrogen production plant comprising at least one electrolyzer stack. Furthermore, the invention relates to a hydrogen production system and a method for operating a hydrogen production plant.

[0005] Hydrogen, especially hydrogen gas, is increasingly used today as an energy carrier or process gas. Hydrogen can be produced from water through electrolysis. In water-based electrolysis, a redox reaction is forced using electrical energy or power, thereby generating hydrogen.

[0006] The hydrogen produced can then be stored in suitable storage facilities and / or fed into a hydrogen network or pipeline system. Alternatively, the hydrogen can be converted into methane, which can then be stored and / or fed into a corresponding pipeline system. The stored hydrogen (or methane) can be converted into electrical energy, for example, using a hydrogen fuel cell (also known as reverse electrolysis) or by combustion in a gas-fired power plant. It goes without saying that the produced hydrogen and / or methane can also be used for other chemical processes.

[0007] Common hydrogen production plants comprise one or more electrolyzer stacks. An electrolyzer stack is designed to generate hydrogen, specifically to perform the electrolysis process described. During operating states (e.g., production or standby) of the electrolyzer, i.e., when electrolysis is being carried out or briefly interrupted, the problem arises that generated hydrogen can escape through (not entirely avoidable) leaks in the area surrounding the electrolyzer stack (including, for example, a fluid connection to another production component of the hydrogen plant connected to a hydrogen outlet, or a seal between the electrolysis cells of the stack). In particular, hydrogen can escape from the electrolyzer stack and, for example, the pipe connections (e.g., flanged or screwed) of the electrolyzer stack into the area surrounding the electrolyzer stack.At these locations, an explosive atmosphere (e.g., > 4% hydrogen in air) can form locally. Accordingly, in the state of the art, a hazard area or an Ex zone 1 or 2 (according to EN 60079-10-1) is designated, particularly depending on the frequency of such an event. Within such a zone, only equipment that cannot act as an ignition source may be used.

[0008] To reduce the risk associated with operating hydrogen production plants, it is common practice to designate hazardous areas (Ex zones) where an explosive atmosphere may occur. Access to these areas is restricted, and only equipment and coatings that do not emit sparks and / or ignition energy, as required by the designated zones, are used.

[0009] Due to hydrogen's tendency to spontaneously ignite, this can only reduce the probability of an accident. Equipment certified for use in hazardous areas is complex and costly, both during installation and operation of the hydrogen production plant.

[0010] Furthermore, it is known from the prior art to provide natural or forced air exchange in the surrounding area around the at least one electrolyzer stack. For example, it is known to provide a

[0011] HB / re 241082WO October 9, 2025 To arrange an electrolyzer stack in a housing with air slots, whereby an airflow generation device (e.g., a fan) creates an airflow through the housing and into the air slots. A potentially escaping hydrogen jet can be rapidly diluted by the constant airflow, and the expansion of the explosive atmosphere (e.g., > 4% hydrogen in air) can be reduced. This is also associated with considerable effort and correspondingly high costs.

[0012] The necessary air exchange significantly increases the operating costs of the hydrogen production plant, as the supply air must be heated, cooled, or cleaned depending on the ambient conditions. Typically, the supply air temperature must be within a permissible range of 5°C to 40°C. The energy required for this reduces the overall efficiency of the hydrogen production plant. Furthermore, the equipment necessary for air exchange (especially the airflow generation device) requires more complex systems and higher investment costs.

[0013] Furthermore, mechanical ventilation is associated with significant noise emissions, which can lead to exceeding the permissible sound pressure level at the system boundary. The state-of-the-art solutions described above are, for example, described in Chapter 4.6 of TRGS 722 (Technical Rules for Hazardous Substances: Avoidance or Limitation of Hazardous Explosive Mixtures).

[0014] In summary, the problems and disadvantages of state-of-the-art solutions include the high cost (as well as high investment costs, operating costs, and noise emissions). Furthermore, while state-of-the-art measures reduce the probability and severity of an explosion, they do not eliminate it entirely. In particular, a so-called "jet fire" with an invisible flame, which is difficult to detect, can occur if hydrogen escapes into air.

[0015] HB / re 241082WO October 9, 2025 Therefore, the invention is based on the objective of providing a hydrogen production plant in which the problems of the prior art are reduced and, in particular, safe operation of the hydrogen production plant is enabled in a less costly manner.

[0016] This problem is solved according to a first aspect of the invention by a hydrogen production plant according to claim 1. The hydrogen production plant comprises at least one electrolyzer stack. The hydrogen production plant comprises at least one housing with at least one first housing area that (completely) surrounds the at least one electrolyzer stack. The hydrogen production plant comprises at least one inert gas generation device fluidically connected to the first housing area. The at least one inert gas generation device is configured to provide an inert gas such that the first housing area is filled with an inert gas mixture at least during one operating state of the at least one electrolyzer stack.

[0017] In contrast to the prior art, the invention involves surrounding the at least one electrolyzer stack with an inert gas mixture during its (active) operating state. This reduces the problems of the prior art and, in particular, enables safer operation of the hydrogen production plant in a less complex manner. Specifically, the inert gas mixture creates a non-reactive or inert gas mixture around the at least one electrolyzer stack, so that even if hydrogen escapes, no explosive atmosphere is formed. Particularly safe operation can be ensured. Mechanical ventilation can be omitted, thus avoiding the associated significant noise emissions.

[0018] The hydrogen production plant according to the invention can be an onshore hydrogen production plant or an offshore hydrogen production plant.

[0019] HB / re 241082WO 9 October 2025 above sea level and / or an offshore hydrogen production facility below sea level.

[0020] The hydrogen production plant according to the invention comprises at least one electrolyzer stack or one electrolysis module. The electrolyzer stack can, for example, be a proton exchange membrane (PEM) electrolyzer stack. It is understood that in variants of the invention, the at least one electrolyzer stack can alternatively or additionally be an electrolyzer stack of a different type, such as an alkaline water electrolyzer stack (AWE), a high-temperature electrolyzer stack, or the like.

[0021] Preferably, the hydrogen production plant according to the invention can comprise a plurality of electrolyzer stacks (e.g., between 2 and 10). An electrolyzer stack is configured to generate hydrogen, and in particular to carry out the described electrolysis.

[0022] In particular, the electrolyzer stack in this case comprises at least one hydrogen outlet with a connected fluid connection section (e.g., a connected section of a hydrogen pipe). The at least one hydrogen outlet (but also other parts of the electrolyzer stack) may include a seal, in particular in the form of a plastic seal. The connected fluid connection section may, for example, be flanged or screwed.

[0023] The hydrogen production plant according to the invention comprises a housing with a first housing section. In one embodiment, the housing can be formed solely by the first housing section. In another embodiment, the housing can comprise a plurality of housing sections.

[0024] The first housing section, or the housing walls of the housing section, surround at least one electrolyzer stack. A particular housing wall of the first housing section can be gas-tight.

[0025] HB / re 241082WO October 9, 2025 The gas-tight design of housing walls with cable and pipe penetrations is described, for example, in DGUV Information 203-092. In this case, at least one gas-tight housing wall of the housing can be designed accordingly. Preferably, all electrolyzer stacks of the hydrogen production plant are surrounded or enclosed by the first housing section. This means, in particular, that the at least one electrolyzer stack is completely enclosed by the housing walls of the first housing section. Any hydrogen potentially escaping from the at least one electrolyzer stack (e.g., from the at least one plastic seal) always (exclusively) enters the first housing section.

[0026] The hydrogen production plant comprises at least one inert gas generation device. The inert gas generation device is configured to provide, and in particular generate, an inert gas. The inert gas generation device is connected (directly or indirectly) to the first housing section via a fluid connection. This means, in particular, that the inert gas generated by the inert gas generation device is fed into the first housing section. For example, the fluid connection can be...

[0027] The fluid connection is formed by one or more pipe(s) that is / are arranged between the inert gas generation device and the first housing area (or, for example, a second housing area which is in turn fluidly connected to the first housing area).

[0028] The inert gas generation device is configured to provide the inert gas such that the first housing section is filled with an inert gas mixture at least during one operating state of the at least one electrolyzer stack. An operating state of the at least one electrolyzer stack means, in particular, that the electrolyzer stack is in a state (e.g., production or standby) in which hydrogen can potentially escape into the first housing section. In particular, a (pressurized) operating state exists when the at least one electrolyzer stack is activated, i.e., especially when...

[0029] HB / re 241082WO October 9, 2025 Electrolysis is (instantaneously) being carried out and hydrogen is being produced, or the electrolyzer is under internal hydrogen overpressure (e.g., standby). In particular, an operating state of the electrolyzer stack is not a state of the electrolyzer stack in which maintenance of the electrolyzer stack is being carried out.

[0030] According to one embodiment of the hydrogen production plant according to the invention, the inert gas generation device can be configured to feed the inert gas into the first housing area in such a way that an inert gas mixture is formed in the first housing area with an inert gas content of at least 80 vol%, preferably at least 94 vol%.

[0031] In particular, it has been found that with a corresponding minimum proportion, the risk of explosion is significantly reduced (to almost 0) even in the event of an unintentional release of hydrogen.

[0032] Alternatively or additionally, the inert gas generation device can be configured to feed the inert gas into the first housing area such that an inert gas mixture with an oxygen content of at least less than 5%, preferably at least less than 1%, is present in the first housing area.

[0033] According to a further embodiment of the hydrogen production plant according to the invention, the inert gas generation device can be configured to feed pressurized inert gas into the first housing area such that an overpressure (compared to the surroundings of the housing) is created in the first housing area. In particular, by creating an overpressure in the first housing area (and, for example, an optional second housing area), it can be ensured that even in the event of an (unintentional) leak in the first housing area, air, particles, and / or the like cannot flow into the first housing area.

[0034] HB / re 241082WO October 9, 2025 Preferably, a predefined overpressure of, for example, 30 to 100 Pascals can be provided, for example, approximately 50 Pascals.

[0035] Preferably, the hydrogen production plant may include a pressure monitoring device. The pressure monitoring device is configured, in particular, to monitor the pressure prevailing in the first housing area at least almost continuously. Preferably, the pressure monitoring device may be configured, at least, to determine the pressure prevailing in the first housing area. For example, determining the pressure may include measuring the pressure using a pressure sensor of the pressure monitoring device.

[0036] The hydrogen production plant can include a pressure control device. This device can be configured to control the inert gas generation unit based on at least one predefined pressure setpoint and the specified pressure. At least one predefined pressure setpoint also includes a predefined permissible pressure range. This reduces the control effort.

[0037] In particular, the amount of inert gas supplied (or the pressure applied to the incoming inert gas) can be reduced if the specified pressure is above the predefined setpoint (or the upper limit of the permissible pressure range). Furthermore, the amount of inert gas supplied (or the pressure applied to the incoming inert gas) can be increased if the specified pressure is below the predefined setpoint (or the lower limit of the permissible pressure range). The pressure in the first (and / or second) housing section can be easily regulated.

[0038] HB / re 241082WO October 9, 2025 In principle, the use of different inert gases is possible. According to a further embodiment of the hydrogen production plant according to the invention, the inert gas generation device can be configured to provide an inert gas selected from the group comprising:

[0039] Nitrogen,

[0040] carbon dioxide, and

[0041] Helium.

[0042] Preferably, the inert gas generation device can be a nitrogen generation device. The nitrogen generation device can, for example, be configured to generate nitrogen by evaporating liquid nitrogen or by pressure swing adsorption (PSA) from ambient air.

[0043] According to a further preferred embodiment of the hydrogen production plant according to the invention, the hydrogen production plant can include a gas mixture monitoring device. The gas mixture monitoring device is particularly configured for at least nearly continuous monitoring of the hydrogen concentration of the inert gas mixture in the first housing area. Preferably, the gas mixture monitoring device can be configured for determining the hydrogen concentration of the inert gas mixture in the first housing area. In particular, determining the hydrogen concentration can include measuring the hydrogen concentration, for example, by means of a sensor of the gas mixture monitoring device. In variants of the invention, other gas concentrations (e.g., oxygen gas concentration, inert gas concentration, etc.) can be monitored accordingly.

[0044] Preferably, the hydrogen production plant can include a gas control device. The gas control device can be configured to control the

[0045] HB / re 241082WO October 9, 2025 Inert gas generation device based on at least one predefined first maximum permissible hydrogen limit and the determined hydrogen concentration. Preferably, the predefined first maximum permissible hydrogen limit can be a threshold value. Upon detection of an exceedance of the threshold value by the gas control device, the inert gas generation device can be controlled such that the amount of inert gas supplied is increased.

[0046] In particular, the inert gas supply can be controlled and regulated so that the hydrogen concentration of the inert gas mixture in the first housing area is kept below the first predefined hydrogen limit. For example, this could be a concentration of 1 / 17 = 6% for hydrogen in a nitrogen gas mixture. According to TRGS 722, with a molar ratio of >17 N₂ to 1 H₂, an explosion or combustion is ruled out even with the addition of any amount of air. This ensures particularly safe operation.

[0047] In other versions of the invention, a higher (first) hydrogen limit value (explosion only at certain implausible mixing ratios or gas-tight housings with inert gas mixture removal via a venting device) or a lower limit value (safety distance to the explosive state) can also be selected. In particular, the first housing area can include at least one hydrogen venting device.

[0048] According to a further preferred embodiment of the hydrogen production plant according to the invention, the gas control device can be configured to issue an alarm message and / or deactivate the at least one electrolyzer stack (in particular all electrolyzer stacks), based on at least one predefined second maximum permissible hydrogen limit and the determined hydrogen concentration, wherein in particular the second maximum permissible

[0049] HB / re 241082WO October 9, 2025 Hydrogen limit is greater than the first maximum permissible hydrogen limit.

[0050] For example, three maximum permissible hydrogen limits can be specified, with the second limit being lower than the third. If, for example, the second limit (especially a second threshold) is exceeded, the gas control device can trigger an alarm message to another computer (e.g., the operator of the hydrogen production plant). If, for example, a third limit (especially a third threshold) is exceeded, the gas control device can deactivate or shut down the hydrogen production plant, thereby reducing the pressure on the system. This can further improve safety.

[0051] Before restarting at least one electrolyzer, the leak point can be located, for example, using a leak detector and / or leak detection spray. Once the leak point has been located, it can be repaired. The hydrogen production plant can then be operated even more safely. In particular, a double gas exchange in the first housing section (and / or the second housing section) may be necessary before restarting at least one electrolyzer.

[0052] In this context, a double gas exchange is understood to mean, in particular, the following: The hydrogen content in the inert gas mixture is below a predefined limit. The first (and / or the second) housing section can be opened from the outside, for example, via a closable opening and / or a housing wall. Preferably, protective measures against inhaling the escaping inert gas mixture can be in place during opening. For example, air can be blown into the first (and / or second) housing section from the outside using a mobile ventilation unit.

[0053] HB / re 241082WO October 9, 2025 In particular, before a user enters the first (and / or second) enclosure area, the first (and / or second) enclosure area can be tested for oxygen levels at one or preferably several points (e.g., using a portable handheld measuring device). This ensures that a sufficient oxygen concentration is present in the opened first (and / or second) enclosure area. Maintenance and / or repair work can then be carried out in the first (and / or second) enclosure area.

[0054] The first (and / or second) housing section can then be closed again, and in particular, a (small) opening to the outside (e.g., a small flap, a slide valve, etc.) in a housing wall can be opened. The inert gas generation device can then be activated, allowing inert gas to flow into the first (and / or second) housing section, so that the first housing section (and optionally a second housing section) is filled with an inert gas mixture. The air-inert gas mixture can (initially) escape through the aforementioned opening. For example, the oxygen content of the air-inert gas mixture can be measured at the opening (using a handheld or permanently installed measuring device), and the opening can be closed if a predefined oxygen limit (e.g., 5%) is undershot. Further discharge of the gas mixture can then occur via a hydrogen venting device (also called a vent), which leads, in particular, into a collection line.The aim is to avoid introducing oxygen here if possible.

[0055] According to a further preferred embodiment of the hydrogen production plant according to the invention, the hydrogen production plant can include a temperature monitoring device. The temperature monitoring device serves in particular for at least nearly continuous monitoring of the temperature of the inert gas mixture. Preferably, the temperature monitoring device is configured to determine the temperature of the inert gas mixture in the first housing area.

[0056] HB / re 241082WO 9 October 2025 of the temperature may include (at least nearly continuous) measurement by a temperature sensor of the temperature monitoring device.

[0057] The hydrogen production plant may include a temperature control device. This device may be configured to control at least one temperature-control device of the hydrogen production plant, based on a predefined permissible temperature range and the specific temperature of the inert gas mixture. The permissible temperature range may be 1°C to 50°C, preferably 5°C to 40°C. By maintaining the temperature within this range, and in particular by controlling it accordingly, safe and optimized operation of the hydrogen production plant can be ensured.

[0058] According to a preferred embodiment of the hydrogen production plant, the at least one temperature control device can include an air conditioning unit. The controllable air conditioning unit can be configured to control the temperature of the inert gas mixture. In particular, the air conditioning unit can be used to cool the inert gas mixture. For example, the air conditioning unit can include a finned heat exchanger with cooling water flow, preferably with a fan (e.g., cooling water inside, fins and fan outside). The cooling water can be a water-glycol mixture, seawater, or concentrated freshwater.

[0059] Alternatively or additionally, the air conditioner can include a room air conditioning unit (e.g., a split air conditioning unit) within the first (and / or second) housing compartment. For example, a (commercially available) wall-mounted air conditioner with remote control can be used. Air conditioning units suitable for air handling are readily available and, in particular, can also function in an inert gas environment. A room air conditioning unit can preferably heat and dehumidify simultaneously and, in particular, drain the condensate to the outside.

[0060] HB / re 241082WO October 9, 2025 Heating the inert gas mixture during operation of the electrolyzer stack can be omitted, particularly due to the waste heat generated during operation. When the system is idle, heating can be achieved electrically. In particular, sufficient frost protection can be provided within the first housing area. Warm surfaces (e.g., of pipes) within the first housing area can preferably be insulated to reduce the amount of heat transferred to the inert gas mixture.

[0061] Furthermore, according to another embodiment of the hydrogen production plant according to the invention, the hydrogen production plant can include a humidity monitoring device. The humidity monitoring device serves, in particular, for the nearly continuous monitoring of the moisture content of the inert gas mixture. Preferably, the humidity monitoring device can be configured to determine the moisture content of the inert gas mixture. Determining the moisture content can, in particular, include measurement by a humidity sensor of the humidity monitoring device.

[0062] The hydrogen production plant may include a humidity control device. This device can be configured to control at least one humidity control unit within the hydrogen production plant, based on a predefined permissible humidity range and the specific moisture content of the inert gas mixture. The predefined permissible humidity range can be from 0 to 90%. Specifically, the moisture content can be controlled by adjusting the amount of inert gas supplied. Furthermore, the humidity control unit can include a dehumidifier configured to dehumidify the inert gas mixture. An increase in humidity can occur due to water escaping from leaks, for example, at the electrolyzer stack. Humidity control can be achieved in a simple manner.

[0063] HB / re 241082WO October 9, 2025 According to a further preferred embodiment of the hydrogen production plant according to the invention, the housing can be a container, in particular an ISO-based container. An ISO-based container can have at least the dimensions of an ISO container (with dimensions of 12.192 m x 2.438 m x 2.591 m (L x W x H)). In this particularly preferred embodiment, all electrolyzer stacks can be located in a first housing area in the form of a first container area.

[0064] In further variants of the invention, the housing, in particular the first housing area, can be a soundproof enclosure, a compartment or a room in a building.

[0065] Preferably, all components of the hydrogen production plant from which hydrogen can escape during a given operating state can be arranged in a (first) housing area that is filled or supplied with an inert gas mixture.

[0066] According to a further preferred embodiment of the hydrogen production plant, the housing can comprise a second housing area separated from the first housing area by a first partition (with or without a closable opening). The first housing area and the second housing area can, in particular, be directly adjacent to one another. The second housing area can comprise at least one hydrogen-based production component, in particular in the form of a hydrogen separator, which is fluidically connected to the at least one electrolyzer stack. For example, the first housing area can comprise all electrolyzer stacks of the hydrogen production plant, and the second housing area can comprise all hydrogen separators of the hydrogen production plant.

[0067] HB / re 241082WO October 9, 2025 The inert gas generation device, fluidically connected to the second housing section, can be configured to supply the inert gas in such a way that the second housing section is filled with an inert gas mixture at least during one operating state of the at least one hydrogen-based production component. The operational safety of the hydrogen production plant can be further improved.

[0068] Preferably, the housing can be an (ISO-based) container with a first container area (as the first housing area) that can be separated (only) by a first partition wall from a second container area (as the second housing area).

[0069] According to a further preferred embodiment of the hydrogen production plant, the inert gas generation device can be fluidically connected to the second housing section, and a valve arrangement can be arranged in the first partition wall, such that the inert gas fed in by the inert gas generation device flows first into the second housing section and then into the first housing section. In other words, the inert gas generation device is fluidically connected to the second housing section, and the second housing section is fluidly connected to the first housing section, such that the inert gas fed in by the inert gas generation device flows sequentially through the second housing section and the first housing section.

[0070] Two separate housing sections, and in particular a sequential flow through them, make it possible to define (and, in particular, to regulate, as described above) different permissible temperature ranges for the respective housing sections and / or different permissible initial hydrogen limits. A division into at least two housing sections, each filled with an inert gas mixture during the respective operating conditions, is particularly advantageous when the hydrogen-based

[0071] HB / re 241082WO October 9, 2025 Production components will be arranged depending on how often they need to be accessed (on average), for example for maintenance purposes.

[0072] In particular, it has been recognized that preferably all electrolyzer stacks of the hydrogen production plant should be arranged in the first housing section and at least all hydrogen separators in the second housing section, since the hydrogen separators, in particular, require more frequent maintenance than the electrolyzer stacks. Double gas exchange can then only be carried out in the second housing section (or only in the first housing section). Operating costs can be reduced even further.

[0073] According to a particularly preferred embodiment of the hydrogen production plant, the housing (in particular in the form of a container) can comprise a third housing area separated from the first housing area or an optional second housing area by a second (gas-tight) partition wall (in particular with or without a closable opening).

[0074] Preferably, a first housing area can be provided, to which the second housing area is connected, to which (in turn) the third housing area can be connected.

[0075] The third enclosure compartment can include at least one (non-hydrogen-based) production component from which no hydrogen can escape (during operation of the hydrogen production plant). The third enclosure compartment can be filled with air. In particular, the third enclosure compartment can include a door or the like. Non-exhaustive examples of non-hydrogen-based production components that can be located in the third enclosure compartment include a data processing device (e.g., with a processor, storage medium, and executable software code) and / or at least one analysis device (e.g., for evaluating measured sensor data) and / or at least one control device (e.g., executable software code), electrical components.

[0076] HB / re 241082WO 9 October 2025 and / or at least one mixed bed filter for process water treatment and / or water pumps.

[0077] By arranging non-hydrogen-based production components in an air-filled housing area, they are (always) accessible to users, for example, for (frequently required) maintenance purposes. Due to the (direct) adjacency of the third housing area to the first and / or preferably second housing area, the at least one non-hydrogen-based production component is (simultaneously) located in the immediate vicinity of the at least one hydrogen-based production component. This may be necessary due to system requirements.

[0078] In further variants of the invention, it may be provided that at least one hydrogen-based production component is arranged in, for example, a fourth (air-filled) housing area, which must be accessed frequently, for example for maintenance purposes.

[0079] Furthermore, according to another preferred embodiment of the hydrogen production plant according to the invention, a door to the third housing area can be arranged in a first narrow side of the (especially ISO-based) container. Preferably, a DC voltage connection connected to the at least one electrolyzer stack can be arranged on or in a region of the second narrow side of the (especially ISO-based) container. "In a region of the second narrow side" particularly means that the DC voltage connection can be arranged on the second narrow side or on another side region of the container (e.g., the bottom, the roof, or a long side) that directly adjoins the second narrow side. The DC voltage connection is particularly designed to be electrically connected to a DC voltage source (e.g., a transformer and / or rectifier device).

[0080] HB / re 241082WO October 9, 2025 According to a further embodiment of the hydrogen production plant according to the invention, the hydrogen production plant can comprise at least one further (non-hydrogen-based) production component, namely at least one oxygen separator, at least one oxygen cooler, and / or at least one oxygen venting device. With the aforementioned (non-hydrogen-based) production components, hydrogen cannot escape, not even potentially (especially compared to hydrogen-based production components).

[0081] At least one of these additional production components can be arranged on the roof of the housing (particularly in the form of a container). Preferably, all of these additional production components can be arranged on the roof, especially above the first and / or second housing section. Insulation and / or electrical heating can be provided for the additional production components, particularly those carrying water. It is understood that further (non-hydrogen-based) production components (e.g., valves) can also be arranged on the roof. A compact hydrogen production plant can thus be provided.

[0082] Another aspect of the invention is a hydrogen production system. The hydrogen production system comprises a (previously described) first hydrogen production plant according to claim 13. The hydrogen production system comprises at least one (previously described) second hydrogen production plant arranged in parallel to the first hydrogen production plant according to claim 13. The hydrogen production system comprises a first transformer and / or rectifier device arranged upstream of the second narrow side of the first hydrogen production plant, which is connected to the DC voltage terminal of the first hydrogen production plant via an electrical connection. The hydrogen production system comprises a second transformer and / or rectifier device arranged upstream of the second narrow side of the second hydrogen production plant.

[0083] HB / re 241082WO 9 October 2025 Rectifier device connected via an electrical connection to the DC voltage connection of the second hydrogen production plant.

[0084] In particular, the hydrogen production system can be formed from at least two substantially identical hydrogen production units, each of which has a container as its housing, in particular an ISO-based container. The containers can be aligned parallel to each other and with their narrow sides facing each other. This means that no container protrudes longitudinally. One long side of the first container can be arranged (directly) adjacent to a long side of the second container. Preferably, these long sides can be in contact at least partially or separated only by an air gap (e.g., between 1 cm and 50 cm).

[0085] A transformer device is specifically designed to transform a voltage, supplied, for example, by a public power grid, a wind farm, a photovoltaic park, etc., to a voltage level required for the operation of, in particular, the at least one electrolyzer stack. A rectifier device is specifically designed to rectify a supplied (transformed) alternating voltage. A direct current voltage is particularly required for the operation of the at least one electrolyzer stack.

[0086] A transformer and / or rectifier device can preferably be arranged in a housing, particularly in the form of a container. The container can be aligned with the container of the associated hydrogen production plant and, for example, have essentially the same width.

[0087] The individual housing compartments of each container, filled with an inert gas mixture, cannot be accessed in its installed or operating position. For maintenance work within the first and / or second housing compartment, the entire container, including roof structures, can be accessed, for example, by a (vehicle)

[0088] HB / re 241082WO October 9, 2025 A crane must be moved to a maintenance area of ​​the hydrogen production system. There, the first and / or second housing section may only be accessible by dismantling a container wall, and / or a second housing section of the container may be accessible from one of its long sides, e.g., for maintenance purposes. Production components, such as an oxygen separator, may also be accessible on the roof of the container. This allows, in particular, multiple containers to be positioned lengthwise without spacing between them. This can significantly reduce the space required for the hydrogen production system.

[0089] A further aspect of the invention is a method for operating a hydrogen production plant, in particular a previously described hydrogen production plant, wherein the hydrogen production plant comprises at least one electrolyzer stack and at least one housing with at least one first housing area (completely) surrounding the at least one electrolyzer stack, comprising:

[0090] Injecting an inert gas at least into the first housing area, such that the first housing area is filled with an inert gas mixture at least during one operating state of the at least one electrolyzer stack.

[0091] A further aspect of the invention is, in particular, a data processing device comprising at least one processor and at least one storage medium, configured for controlling and / or executing the described method. The data processing device may, at least in part, implement the following (previously described) devices, at least partially, as software modules controllable and / or executable by the processor: gas mixture monitoring device, gas control device, temperature monitoring device, temperature control device, humidity monitoring device, and / or humidity control device. The data processing device may, for example, be installed in the third housing area.

[0092] HB / re 241082WO October 9, 2025 A further aspect of the invention is a computer program comprising instructions which, when the computer program is executed by at least one processor of a data processing device, cause it to execute and / or control the method described above (according to claim 16).

[0093] The computer program, especially the instructions or...

[0094] Program instructions can be stored in a computer program product, particularly in program memory. For example, program memory is non-volatile memory such as flash memory, magnetic memory, EEPROM (electrically erasable programmable read-only memory), and / or optical memory.

[0095] Additionally, a data processing device can have main memory, for example, volatile or non-volatile memory, in particular random access memory (RAM), such as static RAM (SRAM), dynamic RAM (DRAM), ferroelectric RAM (FeRAM), and / or magnetic RAM (MRAM). The at least one processor of the parking meter can, for example, store intermediate results or similar data in the main memory.

[0096] The devices described above are preferably at least partially software elements (e.g., executable code) and can be executed by a processor of a data processing device. It should also be noted that terms such as "first," "second," etc., do not indicate an order, but rather serve to distinguish between two elements (e.g.,

[0097] hydrogen production plant, housing area, etc.) serve.

[0098] The features of the hydrogen production plants, hydrogen production systems, and processes can be freely combined. In particular, features of the description and / or the dependent claims can be combined, even in full or

[0099] HB / re 241082WO 9 October 2025 partial circumvention of features of the independent claims, whether acting alone or freely combined, must be independently inventive.

[0100] There are now numerous possibilities for designing and further developing the hydrogen production plant, the process, and the hydrogen production system according to the invention. Reference is made, on the one hand, to the claims subordinate to the independent claims, and on the other hand, to the description of exemplary embodiments in conjunction with the drawing. The drawing shows:

[0101] Fig. 1 shows a schematic view of a hydrogen production plant according to the present invention,

[0102] Fig. 2 shows a schematic view of another hydrogen production plant according to the present invention,

[0103] Fig. 3 shows a diagram of an embodiment of a method according to the invention, and

[0104] Fig. 4 shows a schematic view of a hydrogen production system according to the present invention.

[0105] In the following, similar reference symbols are used for similar elements.

[0106] Figure 1 shows a schematic view of an embodiment of a hydrogen production plant 100 according to the present invention. The hydrogen production plant 100 serves to generate or produce hydrogen by means of water electrolysis.

[0107] HB / re 241082WO October 9, 2025 The hydrogen production plant 100 comprises at least one electrolyzer stack 102 (e.g., PEM stack). The electrolyzer stack 102 is configured to perform water electrolysis to generate hydrogen (and oxygen).

[0108] Furthermore, the hydrogen production plant 100 comprises at least one housing 104 with at least one first housing area 106 (completely) surrounding at least one electrolyzer stack 102. For example, the first housing area 106 can be gas-tight.

[0109] Furthermore, at least one inert gas generation device 108, fluidically connected to the first housing section 106 (e.g., via a fluid connection 110), can be provided. The inert gas generation device 108 is configured to supply an inert gas such that the first housing section 106 is filled with an inert gas mixture at least during one operating state of the at least one electrolyzer stack 102. Any hydrogen potentially escaping from the electrolyzer stack 102 therefore always and only enters the inert gas mixture. This significantly improves safety.

[0110] Preferably the inert gas generation device 108 can be a nitrogen generation device, configured to generate nitrogen and in particular to feed the generated nitrogen into the first housing area 106.

[0111] Figure 2 shows a schematic view of another embodiment of a hydrogen production plant 200 according to the present invention. To avoid repetition, only the differences from the embodiment shown in Figure 1 are described below, and reference is otherwise made, for example, to the explanations relating to Figure 1.

[0112] The depicted hydrogen production plant 200 comprises a plurality of electrolyzer stacks 202 (e.g., PEM stacks). Four are shown only as examples.

[0113] HB / re 241082WO October 9, 2025 Electrolyzer stacks 202 are shown. In the present case, all electrolyzer stacks 202 of the hydrogen production plant 200 are located in the first housing section 206 of the housing 204. In the present case, the housing 204 is preferably a container, in particular an ISO-based container. An ISO-based container can have at least the dimensions of an ISO container.

[0114] Furthermore, in the present embodiment, the housing 204 comprises an optional second housing area 214 and an optional third housing area 216. The second housing area 214 can (directly) adjoin the first housing area 206 and, in particular, can only be separated by a first partition 218 or 216.

[0115] The housing wall is separated from the first housing area 206. The third housing area 216 can (directly) adjoin the second housing area 214 and, in particular, can only be separated from the second housing area 214 by a second partition wall 220 or housing wall. At least the second partition wall 220 can be a gas-tight partition wall.

[0116] As can further be seen from Figure 2, at least one hydrogen-based production component, in particular in the form of a hydrogen separator 222, is arranged in the second housing area 214. The hydrogen separator 222 is in particular completely surrounded by the second housing area 216.

[0117] In particular, any hydrogen potentially escaping from the hydrogen separator 222 (e.g., a plastic seal or the like) can therefore only ever enter the inert gas mixture. It is understood, in particular, that any hydrogen potentially escaping, for example, at the pipe connection points of the hydrogen pipeline network, can only ever escape into the inert gas mixture of the first or second housing section.

[0118] The inert gas generation device 208 (preferably a nitrogen generation device) can feed pressurized inert gas into the second housing area 214 via the fluid connection 210.

[0119] HB / re 241082WO October 9, 2025 A valve arrangement 244 can be arranged in the first partition 218. The valve arrangement 244 can, in particular, permit or allow a gas flow only from the second housing area 214 into the first housing area 206.

[0120] In particular, the inert gas generation device 208 can be fluidically connected to the second housing area 214 and a valve arrangement 244 can be arranged in the first partition wall 218, so that the inert gas supplied by the inert gas generation device 208 first flows into the second housing area 214 and then into the first housing area 206.

[0121] Preferably, the inert gas generation device 208 can be configured to feed pressurized inert gas into the first housing area 206 or the second housing area 214 such that an overpressure (e.g. approx. 50 Pascal) is produced in the first housing area 206 and in particular in the second housing area 214.

[0122] In order to monitor, in particular, the pressure in the first housing area 206 and the second housing area 214, a pressure monitoring device 230 can be provided, preferably with at least one pressure sensor, configured to measure the pressure in the first housing area 206 and, in particular, the second housing area 214. In particular, the respective pressure can be measured continuously.

[0123] Furthermore, a pressure control device 224, executable by the processor 247, can be implemented in a data processing device 246 of the hydrogen production plant, which can comprise at least one processor 247 and a storage medium 249. The pressure control device 224 can be configured to control the inert gas generation device 208 based on at least one predefined pressure setpoint (e.g.,

[0124] The target pressure (overpressure setpoint of 50 Pascals) and the specified pressure. At least one predefined target pressure also includes a predefined permissible pressure range (e.g., overpressure range between 30 and 100 Pascals).

[0125] HB / re 241082WO October 9, 2025 In particular, the quantity of inert gas injected can be reduced (or the pressure applied to the inert gas by the inert gas generation device 208) if the set pressure is above the predefined setpoint pressure (or the upper limit of the permissible pressure range). Furthermore, the quantity of inert gas injected can be increased (or the pressure applied to the inert gas by the inert gas generation device 208) if the set pressure is below the predefined setpoint pressure (or the lower limit of the permissible pressure range).

[0126] Furthermore, the temperature in the first housing area 206 and, in particular, the temperature in the second housing area 214 can optionally be monitored and maintained within a permissible temperature range. In particular, a temperature monitoring device 232 with at least one temperature sensor can be provided. The temperature sensor can, in particular, measure the temperature of the inert gas mixture in the first housing area 206 and, in particular, in the second housing area 214, especially at least almost continuously.

[0127] The hydrogen production plant 200 can include a temperature control device 226, in particular implemented in the data processing device 246. The temperature control device 226 can be executable by the processor 247.

[0128] The temperature control device 226 can be configured to control at least one temperature control device 236 (e.g., a controllable air conditioning unit) of the hydrogen production plant 200, based on a predefined permissible temperature range and the determined temperature of the inert gas mixture. The permissible temperature range can be 1°C to 50°C, preferably 5°C to 40°C.

[0129] HB / re 241082WO October 9, 2025 Different permissible temperature ranges can be provided for the first housing area 206 and the second housing area 214. The controllable air conditioning unit can be configured to influence the temperature of the inert gas mixture. In particular, the air conditioning unit can be used for cooling. For example, the air conditioning unit can include a finned heat exchanger with cooling water flow, preferably with a fan (e.g., cooling water inside, fins and fan outside). The cooling water can be a water-glycol mixture, seawater, or concentrated fresh water. It is understood that other types of temperature control devices can be used in other variants.

[0130] Optionally, the hydrogen concentration can also be monitored by a gas mixture monitoring device 234, in particular with at least one sensor of the gas mixture monitoring device 234. The gas mixture monitoring device 234 or the at least one sensor is in particular configured for at least nearly continuous monitoring of the temperature of the inert gas mixture in the first housing area, in particular by nearly continuous measurement by the at least one sensor.

[0131] Furthermore, the hydrogen production plant 200 can include a gas control device 228, which can be implemented in the data processing device 246 and can be executed in particular by the processor 247.

[0132] The gas control device 228 can be configured to control the inert gas generation device 208 based on at least one predefined first maximum permissible hydrogen limit and the determined hydrogen concentration. For example, the predefined first maximum permissible hydrogen limit can be a threshold value. Upon detection of an exceedance of the threshold value by the gas control device 228, the inert gas generation device 208 can be controlled such that the quantity of inert gas fed into the second housing area is increased.

[0133] HB / re 241082WO October 9, 2025 In particular, the injection of the inert gas can be controlled or regulated such that the hydrogen concentration of the inert gas mixture in the first housing area 206 and especially in the second housing area 214 can be kept below the first predefined hydrogen limit value. In further embodiments of the invention, different first (and / or second and / or third) hydrogen limits can be predefined for the two housing areas 206, 214.

[0134] The gas control device 228 can be configured to issue an alarm message and / or deactivate the at least one electrolyzer stack 202, based on at least one predefined second maximum permissible hydrogen limit and the determined hydrogen concentration, wherein in particular the second maximum permissible hydrogen limit is greater than the first maximum permissible hydrogen limit.

[0135] For example, three maximum permissible hydrogen limits can be predefined, with the second limit being lower than the third. If the second limit (especially a second threshold) is exceeded, the gas control device 228 can, for example, send an alarm message to another (not shown) computer (e.g., the operator of the hydrogen production plant 200). Further measures can then be taken. If a third limit (especially a third threshold) is exceeded, the gas control device 228 can, for example, deactivate or shut down the hydrogen production plant 200 immediately, thereby reducing the pressure.

[0136] Furthermore, it can be seen from Figure 2 that at least the first housing area 206 has a hydrogen venting device 252 (also known as a vent).

[0137] HB / re 241082WO (designated October 9, 2025) includes, for example, a (not shown) hydrogen collection line (of the hydrogen production plant 200).

[0138] In particular, this allows the inert gas mixture to be removed or vented, especially if hydrogen escapes into the first (or second) housing area 206 due to a (sudden) leakage.

[0139] Furthermore, a humidity monitoring device 250 can optionally be provided, in particular with at least one humidity sensor. The humidity sensor can, for example, measure the humidity content in the first housing area 206 and, in particular, in the second housing area 214 at least almost continuously.

[0140] Furthermore, the hydrogen production plant 200 may in particular include a humidity control device 248, which is preferably implemented in the data processing device 246 and may in particular be executable by the processor 247.

[0141] The humidity control device 248 can be configured to control at least one humidity control device 238 of the hydrogen production plant 200, based on a predefined permissible humidity range and the specific moisture content of the inert gas mixture. The predefined permissible humidity range can be 0 to 90%. In particular, the moisture content can be influenced by controlling or regulating the amount of inert gas supplied by the inert gas generation device 208. The humidity control device 238 can include a dehumidifier configured to dehumidify the inert gas mixture and, in particular, to remove the moisture from the first housing area 206 and / or the second housing area 214.

[0142] As already described, the hydrogen production plant 200 preferably comprises a data processing device 246, which is located in particular in the third

[0143] HB / re 241082WO October 9, 2025 Housing area 216 can be arranged. The third housing area 216 is, in particular, an air-filled housing area 216, which is accessible via a door 254 or the like. The door 254 can, in particular, be located in a first narrow side 256 of the housing 204, especially of the container. In variants of the invention, at least one further or different non-hydrogen-based production component of the hydrogen production plant can be installed in the third housing area.

[0144] As can also be seen from Figure 2, a DC voltage connection 264 or DC current connection can be arranged on the second narrow side 258 of the housing 204, designed to supply the at least one electrolyzer stack 202 with DC voltage or DC current.

[0145] Furthermore, at least one non-hydrogen-based production component 240, 242 can be arranged on the roof 266 of the housing 204. Two production components 240, 242 are shown here by way of example. The at least one non-hydrogen-based production component 240, 242 can comprise at least one oxygen separator, at least one oxygen cooler and / or at least one oxygen venting device.

[0146] Figure 3 shows a diagram of an embodiment of a method according to the present application. The method serves to operate and / or control a hydrogen production plant, for example according to Figure 1 and / or 2.

[0147] In step 301, an inert gas is injected into at least the first housing area such that the first housing area is filled with an inert gas mixture at least during one operating state of the at least one electrolyzer stack, as has already been described in particular. In particular, the inert gas can be injected before activation of the at least one electrolyzer stack.

[0148] HB / re 241082WO October 9, 2025 Optionally, in step 303, the hydrogen concentration of the inert gas mixture and / or the temperature of the inert gas mixture and / or the pressure of the inert gas mixture and / or the moisture content of the inert gas mixture can be controlled, as described in particular above.

[0149] Figure 4 shows a schematic view, in particular a schematic top view, of an embodiment of a hydrogen production system 460 according to the present invention. To avoid repetition, only the differences from the previous embodiments are explained below, and reference is otherwise made to the descriptions of Figures 1 and / or 2.

[0150] The hydrogen production system 460 comprises a plurality of hydrogen production units 400.1, 400.2, 400.3. Three hydrogen production units 400.1, 400.2, 400.3 are provided here as examples. Preferably, each of the hydrogen production units 400.1, 400.2, 400.3 can be essentially identical. However, it is understood that in further embodiments of the invention, the hydrogen production units may differ from one another, at least partially, in their construction and / or production components.

[0151] In the present case, each hydrogen production plant 400.1, 400.2, 400.3 comprises a housing 404 in the form of a container, which may in particular be an ISO-based container. The housing 404 may comprise a first housing section 406, a second housing section 414, and a third housing section 416. The first and second housing sections 406, 414 are in particular filled with an inert gas mixture during operation, while the third housing section 416 may be filled with air.

[0152] The first housing section 406 can extend from the second narrow side 458 of the housing 404 to a first partition 418. The second housing section 414 can connect directly to the first housing section 406 and extend from the first partition 418 to a second partition 420. The third

[0153] HB / re 241082WO October 9, 2025 Housing area 416 can connect directly to the second housing area 414 and in particular run from the second partition wall 420 to the first narrow side 456 of the housing 404, in which, for example, a door 454 may be located.

[0154] Preferably, the at least two hydrogen production plants 400.1, 400.2, 400.3 can be arranged in parallel and aligned with each other, as shown in Figure 4.

[0155] Furthermore, the hydrogen production system 460 can comprise at least one transformer and / or rectifier device 462. In the present case, each transformer and / or rectifier device 462 comprises a transformer 468 and a rectifier 470, which may, in particular, be arranged in a further container 472. At least the width of each container 472 can correspond to, and in particular be identical to, the width of the respective container of the respective hydrogen production plant 400.1, 400.2, 400.3.

[0156] As can be seen, an electrical connection 474 (in particular in the form of a DC cable, which can run parallel to each other) can run from the respective rectifier 470 to the respective DC terminal 464 from a first narrow side of the further container 472, which faces the second narrow side 458 of a housing 404. In other words, a respective transformer and / or rectifier device 462 arranged in front of the second narrow side 258 of the respective hydrogen production plant 400.1, 400.2, 400.3 can be connected to the respective DC terminal 464 via a respective electrical connection 474.

[0157] Furthermore, at least one electrical connection 484 (e.g., one or more low-voltage cables) and / or [other electrical connection] can be installed in the space between the respective hydrogen production plants 400.1, 400.2, 400.3 and the respective transformer and / or rectifier devices 462.

[0158] HB / re 241082WO October 9, 2025 At least one fluid connection 484 (e.g., a pipe) for the auxiliary production equipment (also referred to as the balance of plant) of the hydrogen production system 460 must be provided. For example, a common pipe bridge may be provided over which the aforementioned electrical and fluid connections may be routed. A DC cable 474 may, in particular, run below the common pipe bridge. In addition to the at least one (not shown) inert gas generation device, auxiliary production equipment may include, for example, at least one hydrogen compressor, a hydrogen purification device, a water purification device, a cooling water supply, etc.

[0159] As can also be seen from Figure 4, the hydrogen production system 460 may preferably comprise at least one grid connection 476, in particular in the form of a grid connection cable (e.g. an AC (alternating voltage) MV (medium voltage) cable) running in front of the respective first narrow side 478 of the respective transformer and / or rectifier device 462, which may preferably be laid underground.

[0160] Preferably, the hydrogen production system 460 can comprise at least one operating path 480 and, in particular, at least one mobile (lifting) platform 482. The mobile platform 482 (movable on the operating path 480) can, in particular, be configured to provide access to the respective roof of the housings 404 in order to access the at least one production component 440 arranged on the roof, for example, for maintenance purposes.

[0161] Furthermore, the hydrogen production system 460 can include at least one (mobile) crane (movable via the service road 480), which is not shown for clarity. A (wide) service road 480 or maintenance road enables, in particular, the transport of containers and / or transformer and / or rectifier devices 462 by mobile crane. In particular, a corresponding element can be added to a (not shown) maintenance area of ​​the

[0162] HB / re 241082WO October 9, 2025 Hydrogen production system 460 will be transported for maintenance / repair.

[0163] Maintenance routes between hydrogen production plants 400.1, 400.2, and 400.3 can be eliminated, significantly reducing the length of pipe bridges and underground cables, as well as the space required. A particularly compact hydrogen production system, 460, can be provided.

[0164] As indicated in Figure 4 (see especially the arrow), the described setup can be repeated in the x-direction. Alternatively or additionally, the setup can continue in the y-direction.

[0165] HB / re 241082WO October 9, 2025 Reference list:

[0166] 100 hydrogen production plants

[0167] 102 Electrolyzer stack

[0168] 104 cases

[0169] 106 first housing area

[0170] 108 inert gas generating device

[0171] 110 Fluid connection

[0172] 200 hydrogen production plant

[0173] 202 Electrolyzer stack

[0174] 204 cases

[0175] 206 first housing area

[0176] 208 inert gas generating device

[0177] 210 Fluid connection

[0178] 214 second housing area

[0179] 216 third housing area

[0180] 218 first partition wall

[0181] 220 second partition wall

[0182] 222 hydrogen separators

[0183] 224 Pressure regulating device

[0184] 226 Temperature control device

[0185] 228 Gas control device

[0186] 230 Pressure monitoring device

[0187] 232 Temperature monitoring device

[0188] 234 Gas mixture monitoring device

[0189] 236 Temperature control device

[0190] 238 Humidity control device

[0191] 240 production components

[0192] 242 Production component

[0193] 244 Valve arrangement

[0194] HB / re 241082WO October 9, 2025 246 Data processing device

[0195] 247 processor

[0196] 248 Humidity control device

[0197] 249 storage devices

[0198] 250 humidity monitoring device

[0199] 252 Hydrogen venting device

[0200] 254 Door

[0201] 256 first narrow side

[0202] 258 second narrow side

[0203] 264 DC connection

[0204] 266 Roof

[0205] Step 301

[0206] Step 303

[0207] 400 hydrogen production plant

[0208] 404 Housing

[0209] 406 first housing area

[0210] 414 second housing area

[0211] 416 third housing area

[0212] 418 first partition wall

[0213] 420 second partition wall

[0214] 440 Production component

[0215] 454 Door

[0216] 456 first narrow side

[0217] 458 second narrow side

[0218] 460 Hydrogen production system

[0219] 462 Rectifier device

[0220] 464 DC connection

[0221] 468 Transformer

[0222] 470 rectifiers

[0223] 472 containers

[0224] 474 connection

[0225] HB / re 241082WO October 9, 2025 476 Network connection

[0226] 478 Narrow side

[0227] 480 Operating route

[0228] 482 Platform

[0229] 484 Fluid connection

[0230] HB / re 241082WO October 9, 2025

Claims

October 9, 2025 Patent claims 1. Hydrogen production plant (100, 200, 400), comprising: at least one electrolyzer stack (102, 202), at least one housing (104, 204, 404) with at least one first housing area (106, 206, 406) surrounding the at least one electrolyzer stack (102, 202), at least one inert gas generation device (108, 208) fluidically connected to the first housing area (106, 206, 406), configured to provide an inert gas, such that the first housing area (106, 206, 406) is filled with an inert gas mixture at least during one operating state of the at least one electrolyzer stack (102, 202).

2. Hydrogen production plant (100, 200, 400) according to claim 1, characterized in that The inert gas generation device (108, 208) is configured to feed pressurized inert gas into the first housing area (106, 206, 406) such that an overpressure is created in the first housing area (106, 206, 406).

3. Hydrogen production plant (100, 200, 400) according to claim 1 or 2, characterized in that the inert gas generation device (108, 208) is configured to provide an inert gas selected from the group comprising: Nitrogen, carbon dioxide, and Helium.

4. Hydrogen production plant (100, 200, 400) according to one of the preceding claims, characterized in that the hydrogen production plant (100, 200, 400) includes a gas mixture monitoring device (234), configured at least for determining a hydrogen concentration of the inert gas mixture in the first housing area (106, 206, 406), and The hydrogen production plant (100, 200, 400) includes a gas control device (228) configured to control the inert gas generation device (108, 208) based on at least one predefined first maximum permissible hydrogen limit and the determined hydrogen concentration.

5. Hydrogen production plant (100, 200, 400) according to claim 4, characterized in that the gas control device (228) is configured to issue an alarm message and / or to deactivate the at least one electrolyzer stack (104, 204) based on at least one predefined second maximum permissible hydrogen limit and the determined hydrogen concentration, wherein in particular the second maximum permissible hydrogen limit is greater than the first maximum permissible hydrogen limit.

6. Hydrogen production plant (100, 200, 400) according to one of the preceding claims, characterized in that The hydrogen production plant (100, 200, 400) includes a temperature monitoring device (232) configured to determine the temperature of the inert gas mixture in the first housing area (106, 206, 406), and The hydrogen production plant (100, 200, 400) comprises a temperature control device (226) configured to control at least one temperature control device (236) of the hydrogen production plant (100, 200, 400), based on a HB / re 241082WO October 9, 2025 predefined permissible temperature range and the specific temperature of the inert gas mixture.

7. Hydrogen production plant (100, 200, 400) according to claim 6, characterized in that comprising at least one temperature control device (236) an air conditioning unit, configured to control the temperature of the inert gas mixture.

8. Hydrogen production plant (100, 200, 400) according to one of the preceding claims, characterized in that The hydrogen production plant (100, 200, 400) includes a moisture monitoring device (250) designed to determine the moisture content of the inert gas mixture, and the hydrogen production plant (100, 200, 400) includes a humidity control device (248) configured to control at least one humidity control device (238) of the hydrogen production plant (100, 200, 400) based on a predefined permissible humidity range and the determined moisture content of the inert gas mixture.

9. Hydrogen production plant (100, 200, 400) according to one of the preceding claims, characterized in that the housing (104, 204, 404) is a container, in particular an ISO-based container.

10. Hydrogen production plant (100, 200, 400) according to one of the preceding claims, characterized in that the housing (104, 204, 404) comprises a second housing area (214, 414) separated from the first housing area (106, 206, 406) by a first partition (218, 418), HB / re 241082WO October 9, 2025 wherein the second housing area (214, 414) comprises at least one hydrogen-based production component fluidly connected to the at least one electrolyzer stack, in particular in the form of a hydrogen separator (222), and wherein the inert gas generation device (108, 208) which is fluidically connected to the second housing area (214, 414) is configured to provide the inert gas such that the second housing area (214, 414) is filled with an inert gas mixture at least during one operating state of the at least one hydrogen-based production component.

11. Hydrogen production plant (100, 200, 400) according to claim 10, characterized in that the inert gas generation device (108, 208) is fluidically connected to the second housing area (214, 414) and a valve arrangement (244) is arranged in the first partition (218, 418) so that the inert gas supplied by the inert gas generation device (108, 208) first flows into the second housing area (214, 414) and then into the first housing area (106, 206, 406).

12. Hydrogen production plant (100, 200, 400) according to one of the preceding claims, characterized in that the housing (104, 204, 404) comprises a third housing area (216, 416) separated from the first housing area (106, 206, 406) or a second housing area (214, 414) by a second partition (220, 420), wherein the third housing area (216, 416) comprises at least one production component from which no hydrogen can escape, and wherein the third housing area (216, 416) is filled with air.

13. Hydrogen production plant (100, 200, 400) according to claims 9, 10 and 12, characterized in that HB / re 241082WO October 9, 2025 in a first narrow side (256, 456) of the container a door (254, 454) to the third housing area (216, 416) is arranged, and a DC voltage connection (264, 464) is arranged on the further narrow side (258, 458) of the container, which is connected to at least one electrolyzer stack.

14. Hydrogen production plant (100, 200, 400) according to one of the preceding claims, characterized in that the hydrogen production plant (100, 200, 400) includes at least one further production component (240, 242, 440) comprising at least one oxygen separator, at least one oxygen cooler and / or at least one oxygen venting device, wherein at least one of the further production components (240, 242, 440) is arranged on a roof (266) of the housing (104, 204, 404).

15. Hydrogen production system (460), comprising: a first hydrogen production plant (100, 200, 400) according to claim 13, at least a second hydrogen production plant (100, 200, 400) arranged in parallel to the first hydrogen production plant (100, 200, 400) according to claim 13, a first transformer and / or rectifier device (462) arranged in front of the second narrow side of the first hydrogen production plant (100, 200, 400), which is connected via an electrical connection to the DC voltage connection (264, 464) of the first hydrogen production plant (100, 200, 400), and a second transformer and / or rectifier device (462) arranged in front of the second narrow side of the second hydrogen production plant (100, 200, 400), which is connected via an electrical connection to the DC voltage connection (264, 464) of the second hydrogen production plant (100, 200, 400). HB / re 241082WO October 9, 2025 16. Method for operating a hydrogen production plant (100, 200, 400), in particular a hydrogen production plant (100, 200, 400) according to any one of the preceding claims 1 to 14, wherein the hydrogen production plant (100, 200, 400) comprises at least one electrolyzer stack (102, 202) and at least one housing (104, 204, 404) with at least one first housing area (106, 206, 406) (completely) surrounding the at least one electrolyzer stack (102, 202), comprising: Injecting an inert gas at least into the first housing area (106, 206, 406) such that the first housing area (106, 206, 406) is filled with an inert gas mixture at least during one operating state of the at least one electrolyzer stack (104, 204, 404). HB / re 241082WO October 9, 2025

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