Offshore electrolysis system and method for operating offshore electrolysis system

Abstract

The invention relates to an offshore electrolysis system (100) comprising a wind power generation device (1) with a platform (3) and an electrolysis device (5) arranged on the platform (3), the electrolysis device being coupled to the wind power generation device (1) in order to supply an electrolysis current, and a water supply device (7) coupled to the electrolysis device (5), the water supply device having a water collector (13) configured to collect the electrolysis current from the wind power generation device (1). In this way, it is possible to obtain water that does not contain salt or only contains a very small amount of salt without relying on seawater, which can be used as reactant water for operating the electrolysis device (5). The invention also relates to a method for operating a corresponding marine electrolysis system (100), in which water of a quality is obtained in the water collector (13), independent of seawater, such that the obtained water contains no salt or only a very small amount of salt.

Description

Technical Field

[0001] This invention relates to an offshore electrolysis system and a method for operating the offshore electrolysis system. Background Technology

[0002] An electrolysis system is a device that uses electric current to perform the conversion (electrolysis) of substances. Corresponding to various electrochemical electrolysis processes, there are also various electrolysis devices, such as those used for water electrolysis. To provide direct current for the electrolysis process, the electrolysis device is connected to a power generation device, thus forming an electrolysis system. Typically, electrolysis devices have multiple electrolytic cells, allowing for large electrolysis power outputs when expanded accordingly, enabling electrochemical conversion of substances.

[0003] Currently, hydrogen is produced from water, for example, through proton exchange membrane (PEM) electrolysis or alkaline electrolysis. Electrolysis equipment uses electrical energy to produce hydrogen and oxygen from a supplied water source. This process takes place in an electrolytic reactor consisting of multiple electrolytic cells. In the electrolytic reactor, which operates under direct current voltage, water is introduced as a reactant, resulting in two fluid streams: one of water and one of gas bubbles (O2 or H2), flowing through the electrolytic cells.

[0004] The current consideration is to utilize surplus energy from renewable energy sources to produce valuable substances during periods of abundant sunshine and strong winds (i.e., when solar or wind power generation is above average). Valuable substances could, in particular, be hydrogen produced through water electrolysis. Hydrogen can then be used to produce, for example, so-called renewable energy gas (RE-gas). Renewable energy gas is a combustible gas obtained from renewable energy sources using electricity.

[0005] Hydrogen is a particularly environmentally friendly and sustainable energy carrier. It has unique potential to enable many areas of energy systems, transportation, and the chemical industry without emitting carbon dioxide. However, to achieve this, hydrogen must not be derived from fossil fuels but must be produced using renewable energy sources.

[0006] Wind energy is a source of renewable energy. In particular, offshore wind power, especially near-shore systems, can generate significant amounts of electricity. However, the challenge lies in traversing long distances from the load. Therefore, energy should be delivered to the load with minimal loss. Hydrogen is well-suited as a transport medium. It can be transported, for example, in gaseous form via pipelines. A positive side effect of this is that the hydrogen transport pipeline can simultaneously function as an energy storage device, as its internal pressure can vary within certain limits. For this reason, it is particularly important to produce hydrogen directly at the energy generation site, i.e., to install electrolysis equipment at or near the offshore wind power plant. Thus, offshore electrolysis systems are currently being discussed, for example, where electrolysis equipment is installed directly on the offshore wind power plant platform. Here, the wind power equipment can be interconnected with the electrolysis equipment to form a essentially self-sufficient, almost grid-independent electrolysis system, specifically designed for operation on isolated offshore islands.

[0007] In the best-case scenario, these electrolysis systems, combining wind power and electrolysis equipment, can be established entirely without auxiliary connection to the power grid and are designed solely for island operation. This is particularly relevant for offshore electrolysis systems, which need to avoid long-distance connections to the public power grid in coastal areas. Ideally, electrolysis equipment with multiple electrolyzers is located directly near renewable energy sources (i.e., wind power equipment) to reduce or eliminate conversion and line losses. Therefore, offshore electrolysis systems, especially those with integrated electrolysis equipment, are currently being heavily developed, with these devices directly mounted on platforms equipped with offshore wind power generation systems. In this configuration, the equipment can operate even without grid connection, whether "onshore" or "offshore." However, without grid connection, power cannot be supplied by either generators or the grid during periods of calm, low wind speeds, or, for example, during planned maintenance of the wind turbines.

[0008] Offshore electrolysis systems require special attention to prevent corrosion of the equipment, as the presence of seawater significantly accelerates the corrosion rate, jeopardizing long-term uninterrupted operation. In principle, offshore electrolysis equipment can be equipped with electrolytic cells, which can be housed in enclosed hulls or containers. This provides a degree of protection against external environmental influences. However, during normal operation, the electrolytic cells must be cooled to continuously dissipate the waste heat generated by the electrolysis process. Compared to onshore electrolysis equipment, thermal management of offshore electrolysis equipment is generally more challenging, both in terms of cooling required during normal operation and maintaining minimum temperatures during prolonged shutdowns. In the latter operating mode, especially during periods of low wind and light, such as in winter and when wind power equipment is shut down, it is crucial to ensure adequate freeze protection for the submerged electrolytic cells. Therefore, to meet the cooling requirements of offshore electrolysis equipment during normal operation, at least a closed container structure is required, i.e., the electrolyzer is protected by a shell. This requirement must simultaneously prevent overheating and failure of the electrolyzer, and also prevent harmful corrosion caused by exposure to seawater salinity. Thus, in offshore electrolysis equipment, the interface and exchange between the electrolyzer and the environment are ultimately unavoidable, in order to properly dissipate the heat flow from the process during normal operation and achieve safe operation.

[0009] To protect electrolyzers from environmental impacts, they therefore require enclosures, such as containers, as mentioned above. Water management is particularly challenging in water-based offshore electrolysis systems. However, the internal temperature of the container must also not fall below approximately 5°C. Otherwise, the water-containing transport components may freeze, paralyzing the entire system. This would defeat the purpose of offshore electrolysis systems with wind power that are not connected to the power grid, aiming for minimal maintenance and maximum self-sufficiency.

[0010] Electrolysis equipment with water electrolyzers, especially PEM (proton exchange membrane) water electrolyzers, must operate using deionized and high-purity water as reactants. Even in alkaline electrolysis, such as electrolysis using aqueous concentrated potassium hydroxide solution as a reactant, the purity and quality requirements for water or alkaline aqueous solutions are extremely high. Therefore, in addition to thermal management, special requirements are placed on water management in offshore electrolysis systems to ensure continuous operation and a supply of high-quality, high-purity reactant water. Summary of the Invention

[0011] The object of this invention is to provide a marine electrolysis system configured to better supply reactant water, wherein the production efficiency of hydrogen production is improved compared to known schemes. Another object of this invention is to provide a method for operating a marine electrolysis system.

[0012] According to the present invention, the purpose of the marine electrolysis system is achieved by a marine electrolysis system comprising a wind power generation device with a platform and electrolysis equipment arranged on the platform, the wind power generation device being connected to the electrolysis equipment to supply electrolysis current, and the marine electrolysis system further comprising a water supply device connected to the electrolysis equipment, the water supply device having a water collector configured to obtain water that is saline-free or contains only a very small amount of salt without relying on seawater, the water being usable as reactant water for operating the electrolysis equipment.

[0013] According to the present invention, the objective of the method for operating a corresponding marine electrolysis system is achieved by a method for operating a marine electrolysis system, wherein water with the following quality is obtained in a water collector without relying on seawater, namely, the obtained water is free of salt or contains only a very small amount of salt.

[0014] The following advantages and preferred embodiments of the marine electrolysis system can be adapted to the operation method of the electrolysis system.

[0015] The energy input required for water supply and treatment of the electrolysis equipment using offshore electrolysis systems and operating methods has been significantly improved. This allows for the continuous and on-demand supply of high-purity, high-quality reactant water to the electrolysis process. Simultaneously, it enables safe, environmentally friendly, and self-sufficient operation with low maintenance costs. The water supply system also has low maintenance costs and minimal intervention requirements because it does not rely on seawater and, in practice, does not require the use of seawater.

[0016] This invention is based on the fact that, in addition to electrical energy, water is required to decompose water during electrolysis. Producing approximately one kilogram of hydrogen requires at least nine liters of water. If the water needs to be treated, i.e., desalinated or deionized, the consumption increases significantly. In all industrial electrolysis processes, such as PEM (proton exchange membrane) electrolysis or alkaline electrolysis, water must meet specific purity requirements; otherwise, impurities or foreign ions continuously supplied to the process water circulation will accumulate in the water supply system. The average salinity of seawater is 3.5% by mass. Salinity varies depending on the sea area. Therefore, the salinity of the Baltic Sea is 0.2% to 2%, and the Dead Sea has a salinity of 28%. Studies have explored using seawater as an electrolyte in electrolysis. However, salt concentrations and the ability to handle sparingly soluble components can currently only be achieved under laboratory conditions for short operating times. In large-scale commercial electrolysis equipment, desalination and purification of seawater remain essential and require significant energy. In offshore electrolysis systems, the energy requirement for producing fully desalinated, high-purity reactant water has a very negative impact on the efficiency of hydrogen production relative to the electrical power used by wind power generation units.

[0017] The increasing number of installed or planned offshore wind power installations with greater capacity and independent of the power grid, along with their ever-increasing power generation, necessitates correspondingly higher-capacity electrolysis equipment and higher water consumption. Therefore, it is anticipated that the power levels and number of offshore electrolysis systems will increase significantly in the future.

[0018] The increasing demands for safe and environmentally friendly operation in the marine environment must be considered. As efforts to scale up offshore electrolysis systems to larger scales in the open ocean become more focused, in addition to the environmental compatibility of such systems, the issue of achieving self-sufficiency—that is, operating on isolated islands using 100% renewable wind energy without relying on the power grid—has become a key point of discussion. Here, from an environmental perspective, it is essential to ensure operation with the lowest possible impact on the marine economic system. Therefore, a self-sufficient and low-impact solution that provides a safe water supply for electrolysis equipment is crucial for energy and ecological balance.

[0019] The solution of this invention ensures water supply and replenishment, minimizing dependence on seawater because a water collector independent of seawater is installed, enabling the collection and acquisition of saline water from natural sources without relying on seawater. Water treatment costs are significantly reduced compared to seawater. Depending on the marine installation location of the offshore electrolysis system, water volume can be utilized and supplied to the electrolysis process. The water collector of the water supply device is designed in terms of collection capacity and effective collection area based on the required or available water volume.

[0020] This invention's marine electrolysis system advantageously recognizes and overcomes, for the first time, the drawbacks of conventional water supply schemes in grid-independent electrolysis systems, which, as previously mentioned, require very high energy consumption and equipment investment for seawater desalination and treatment. Seawater desalination refers to the extraction of drinking water and process water for industrial or power generation equipment from seawater (brine) by reducing its salt content. Desalination can be achieved based on various processes capable of removing dissolved minerals from water. Some of these processes produce usable byproducts, such as table salt. The energy consumption in multi-stage flash distillation of seawater is 23–27 kWh / m³. 3 Approximately 90 MJ / m 3In reverse osmosis, approximately 2 to 4 kWh of drinking water is required per cubic meter. The physical minimum is 1.9 kWh per cubic meter. However, the membranes in reverse osmosis systems are not maintenance-free. Fouling caused by mineral deposits (scaling), biological material (biofouling), or colloidal particles reduces the permeability of water molecules through the membrane. These drawbacks are overcome by integrating the water collector into the electrolysis system according to the present invention. The potential dependence on seawater, along with the associated equipment costs and energy consumption, is significantly reduced. The water supply unit can also be additionally configured to use seawater as needed for emergency supply. However, this allows for a significantly smaller size in terms of equipment technology compared to conventional water supply systems. In this regard, a hybrid water supply unit can also be used in marine electrolysis systems. However, it is generally preferred to obtain water independently of seawater through the water collector.

[0021] In a particularly preferred embodiment of the offshore electrolysis system, the water supply device has a temporary storage section disposed on a platform and / or installed in the tower of the wind power generation device, wherein the temporary storage section is connected to a water collector.

[0022] If necessary, a pump can be installed here to transport the water collected in the collector to the storage section, thereby periodically emptying the collector at least partially based on the water output and level. This establishes a water reserve and allows for future use. Installing the storage section within the tower (similar to a reservoir) advantageously provides a chamber without requiring additional structural space on the platform. Therefore, the storage section can be easily formed or constructed as a chamber within the tower of the wind turbine. The storage section is thus preferably embedded deep within the tower, below the water surface, to utilize the relatively constant and frost-free ambient temperature within the submerged storage section. Simultaneously, placing the storage section in a chamber deep within the tower has minimal impact on the tower structure and the mechanical stability of the nacelle carrying the wind turbine. Furthermore, it provides or fully utilizes previously unused structural space. In this embodiment, the storage section requires no area or structural space on the platform itself, which can be used for the electrolysis equipment and its components without the limitation of a water supply system.

[0023] The corresponding storage capacity for the temporary storage section can also be achieved using water tanks installed below the platform. These tanks are insulated, depending on the geographical location of the electrolysis system, to prevent the stored water from freezing. The temporary storage section ensures that the collector is periodically emptied or unloaded, while maintaining sufficient water reserves to meet at least several days' worth of electrolysis needs. This allows for safe passage through periods of low water levels in the collector.

[0024] In a particularly preferred embodiment of the marine electrolysis system, a purification device is provided, which is connected to the temporary storage section via an extraction pipeline.

[0025] This enables the treatment and purification of water collected and stored in the collector and temporary storage section for use in electrolysis equipment. Although the water initially collected in the collector already has very low salinity or is salt-free, it may still contain suspended particles, impurities, and small amounts of residual water-soluble ions. Depending on the installation location of the electrolysis system, the collected water may contain cations, such as sodium ions (Na+). + Potassium ions K + Magnesium ions (Mg) 2+ Calcium ions (Ca) 2+ ammonium ions NH4 + It may also introduce or dissolve anions, such as chloride ions (Cl). - nitrate ions NO3 - or sulfate ions SO4 2- Because the collected water is already of high purity, the loading of these substances is low. Therefore, the design and size of the purification device can be significantly smaller than that of a corresponding seawater treatment device. The wind power generation device also requires significantly less energy because the collected water is already well-purified. Consequently, the electricity generated in the offshore wind power generation device can be primarily used for electrolysis, thereby improving the hydrogen production efficiency relative to available electrical energy.

[0026] In a preferred embodiment of the marine electrolysis system, the purification device is connected to the storage container via a storage pipeline, thereby allowing the treated water to be delivered to the storage container as reactant water and providing backup for the operation of the electrolysis equipment.

[0027] The water obtained and treated in the purification unit is stored in a storage container connected downstream of the purification unit. The purified reactant water is stored through a storage line. The storage container provides treated, fully desalinated reactant water for later use, allowing reactant water to be fed into and replenish the process water circulation of the electrolysis unit as needed.

[0028] Therefore, in a preferred embodiment of the marine electrolysis system, the storage container is connected to the electrolysis equipment via an input pipeline.

[0029] To input, replenish, or supplement the process water into the process water circulation system, a transfer pump is installed in the input pipeline. Furthermore, a controllable metering valve can be connected to the input pipeline to achieve precise quantitative addition and balancing of the reactant water based on the conversion rate and water consumption during electrolysis. According to the equipment principle, reactant water can be input into the electrolytic cell used for water electrolysis from either the anode side or the cathode side.

[0030] In a particularly preferred embodiment of the marine electrolysis system, the water collector has a rainwater collector configured to collect rainwater.

[0031] In this way, rainwater, such as precipitation, can be collected through a rainwater collector designed with a large collection area and appropriate size.

[0032] Preferably, the rainwater collector has a pool, wherein the pool is fixed on a platform and / or floated on the sea surface.

[0033] The water tank serves as a collection basin and can be situated on a separate offshore platform adjacent to the offshore electrolysis system, functioning as a supply platform. This supply platform, in addition to the water tank, can also accommodate a temporary storage unit for precipitation and, if necessary, other components of the water supply system. The temporary storage unit is preferably 100–500 m in diameter. 3 The temporary storage unit is suspended below the platform. This unit allows for the temporary storage of rainwater collected in the collection pool, providing a reserve for subsequent purification steps. The pool has a large collection area of ​​at least several hundred square meters, for example, 500 m². 3 Up to 1000 m 3 Multiple collection pools can also be installed to increase the collection volume. The precipitation collector can be flexibly scaled up to meet predicted water demand. This is based on an average annual precipitation of 500 l / m³. 2 In this case, every 100 m of this pool 2 Collection area: 50 m 3 Water. Alternatively, in a large-scale offshore electrolysis system, multiple electrolysis units arranged on corresponding platforms are supplied with water by a central water supply unit with a water collector.

[0034] In a particularly preferred embodiment of the marine electrolysis system, the water collector has a condensation device configured to condense saturated humid air.

[0035] Therefore, in addition to or as an alternative to precipitation collectors, a possibility is provided for obtaining water from the condensation of humid ambient air. Moisture (Feuchtigkeit) is condensed and can be collected as water. This can be achieved by condensation from the ambient air of the marine electrolysis system, or by condensation within equipment components. It is also feasible to integrate the condensation unit onto the platform supporting the electrolysis equipment, or to construct it as a supply platform on a specially designed offshore platform. This supply platform is part of the water supply system. In the condenser, saturated humid air is cooled, and gaseous water vapor is converted into droplets due to being below the dew point.

[0036] Preferably, the marine electrolysis system has a condensation device with a mist collector, which has a large-area net with fine mesh as the collector, particularly a nylon net or a polypropylene net.

[0037] The term fog condensation also refers to the extraction of water by promoting the condensation of water vapor using fog collectors. Research and practical experience in the use of fog collectors have significantly improved their water production efficiency, making them suitable and advantageous for use as water collectors in the water supply systems of offshore electrolysis equipment. For example, when cold ocean currents flow to the sea surface near the coast, the air humidity transported by onshore winds condenses below the dew point, forming water fog. The choice of materials, mesh size, and fabric shape (dotted structure, porous structure, and honeycomb structure) is crucial for the fog collection efficiency of fog collectors used to extract water droplets from the fog. The fog collector can be flexibly scalable, and its size can be adapted to the water requirements of the electrolysis equipment through effective area and collection capacity.

[0038] In alternative or additional embodiments of the offshore electrolysis system, the condensation unit is equipped with a condenser dryer, wherein the condenser dryer is arranged inside the tower or pod of the wind power generation unit.

[0039] Compared to fog collectors that act as surface collectors, locally capturing and separating moisture from the direct operating environment of the functional components of an offshore electrolysis system can be highly suitable and advantageous. On the one hand, this provides excellent protection for the active components of the wind power generation unit (e.g., electrical components within the pod or tower), preventing moisture damage or short circuits. Similarly, moisture must be prevented from the electrolyzer, electrolytic cells, and the power supply system of the electrolysis equipment to prevent and minimize corrosion damage or injury to electrical components. Therefore, a dry operating environment, i.e., dry ambient air within the operating space or casing, is particularly important for maintaining long-term functional stability. On the other hand, virtually salt-free water can be obtained through a condenser dryer. Condensation drying is an air dehumidification method commonly used in industrial and civil applications, such as clothes dryers or conventional building dryers. For this purpose, humid air is guided by a fan through cooling fins / radiators, where the temperature is below the air's dew point. Here, water condenses and accumulates as condensate on the cold surface, which is collected in a separate container. The cooled and dehumidified air is then heated and discharged as dry air. Advantageously, the condenser dryer in this solution can be installed locally and integrated into the water supply system. The condenser dryer can be easily powered by electricity from a wind power plant.

[0040] In a particularly preferred embodiment of the marine electrolysis system, the electrolysis equipment includes an electrolytic cell and a condensation device arranged in a container, thereby enabling the condensation of moisture in the container and creating dry operating conditions.

[0041] This advantageously creates a defined, dry operating environment and provides operating space for the electrolyzer via containers. The container structure protects the electrolyzer from harmful environmental influences, particularly salt intrusion. This is a preferred arrangement for offshore operation of electrolyzers, with containers positioned on platforms. The condensation unit within the container is designed to ensure that the relative humidity is always below 40%, preferably even below 30%, typically between 15% and 25%. This meets the permissible humidity requirements for operation and correspondingly reduces them to a minimum. The condensate produced by the condensation unit, as described above, is used in a similar manner, through temporary storage in a buffer section, purification in a purification unit, and storage in a storage container, thereby providing high-quality, treated reactant water suitable for electrolysis purposes.

[0042] In a particularly preferred embodiment of the offshore electrolysis system, an isolated power grid that is not connected to the power grid is realized.

[0043] This implementation of the offshore electrolysis system enables grid-independent operation, which is particularly economical. Here, hydrogen is generated directly at the energy source during water electrolysis, meaning the electrolysis equipment is deployed directly at or near the offshore wind power generation unit. Thus, the wind power unit and the electrolysis equipment are interconnected to form a self-sufficient, virtually grid-independent electrolysis system, specifically configured for operation on isolated offshore islands. To withstand periods of no wind or sunlight, auxiliary battery packs can be installed to maintain minimum system-related functions of the electrolysis equipment.

[0044] In another preferred embodiment of the marine electrolysis system, the electrolysis equipment includes an electrolyzer for water electrolysis based on proton exchange membrane (PEM) electrolysis or alkaline electrolysis, with hydrogen (H2) as the product gas.

[0045] In proton exchange membrane (PEM) electrolysis, by integrating the water supply device into the marine electrolysis system, fully desalinated water can be obtained as a reactant without relying on seawater. For alkaline electrolysis, high-purity water is also required as a solvent for hydroxides when preparing the alkaline solution. In alkaline electrolysis, an aqueous solution of potassium hydroxide (KOH) is typically used as the reactant solution to form a potassium alkali solution.

[0046] Therefore, depending on the needs, combinations of different electrolyzers used for water electrolysis can be used in offshore electrolysis systems, and can be adapted according to the load scheme. Alkaline electrolyzers operate in a quasi-steady-state state at rated power under optimal conditions, while PEM electrolyzers are capable of variable load operation, especially suitable for partial loads below 30% of rated power. Both technologies produce hydrogen and oxygen as product gases. In addition to being transported via pipeline and further utilized on land as stipulated, some hydrogen can be temporarily stored in local hydrogen storage tanks on the platform.

[0047] Another aspect of the invention relates to a method for operating a corresponding marine electrolysis system.

[0048] Here, water of a certain quality is obtained through a water collector without relying on seawater, and the water obtained therein contains no salt or only a very small amount of salt.

[0049] This method can be advantageously implemented self-sufficiently, without requiring large amounts of seawater or the operation of large-scale seawater desalination plants typically necessary to obtain reactant water.

[0050] In an advantageous embodiment of the method, precipitation is collected and / or water is obtained from condensed saturated moist air.

[0051] This provides a particularly efficient method for obtaining sufficient quantities and quality of reactant water. When deployed in a marine environment, precipitation occurs regularly, predicted to reach several hundred liters per square meter annually. This precipitation can be utilized. As a supplement or alternative to the use of precipitation, the method also proposes to utilize the condensation of moisture in the ambient air both outside and inside the electrolysis system. The generated and obtained condensate is of good quality and can be used.

[0052] Therefore, it is preferable to configure the method to process the obtained water and then supply the processed water as reactant water to the electrolysis equipment.

[0053] This enables the on-demand and quantitative replenishment of treated reactant water. The replenishment is controlled, maintaining the liquid level in the electrolyzer based on the electrolysis power and the resulting water consumption, thus supplying reactant water to the electrolyzer. Control and regulation devices, along with corresponding transfer pumps and regulating accessories, are provided for this purpose. Attached Figure Description

[0054] Figure 1 An offshore electrolysis system with electrolysis equipment and wind power generation device is shown;

[0055] Figure 2 The schematic diagram illustrates the functional components of a water supply device and the components of a process for obtaining water without relying on seawater.

[0056] Figure 3 A schematic side view of an offshore electrolysis system with a water supply device is shown.

[0057] Figure 4 A marine electrolysis system with a rainwater collector is shown;

[0058] Figure 5 A condensation device configured as a mist collector is shown. Detailed Implementation

[0059] The same reference numerals in the accompanying drawings have the same meaning.

[0060] Figure 1 The image shows an offshore electrolysis system 100. The offshore electrolysis system 100 includes an electrolysis unit 5 and a wind power generation device 1, the wind power generation device having a tower 19 and a turbine rotor, such as... Figure 1 As shown in the upper right section. In the lower region of tower 19, platform 3 is fixed to the tower above sea level 25 (see...). Figure 4 and Figure 5 The platform was specifically designed and constructed to house the various equipment components required for the intended operation of the offshore electrolysis system 100. These equipment components are located in... Figure 1 The lower part is shown as an example with an enlarged illustration:

[0061] An electrolysis unit 5 is installed on platform 3 and is systematically connected to the wind power generation unit 1 to form an offshore electrolysis system 100. For this purpose, containers 9 are specifically arranged on platform 3, housing electrolysis elements (not shown in detail), such as individual electrolytic cells, thereby protecting the particularly sensitive functional components of the electrolysis unit 5 from weather effects. Each container 9 on platform 3 includes and protectively houses control devices 27 or so-called "auxiliary facilities" components. Containers 9 are selected here and are typically dedicated to individually housing and operating these control devices 27 and any other possible auxiliary systems for the electrolysis unit 5. The electrolytic cells for electrochemical conversion are arranged in containers 9 specifically designed for this purpose. Other components or equipment parts housed in containers 9 may also be storage containers for electrolytes used to operate the electrolytic cells, or storage containers for fully desalinated water or potassium hydroxide solutions, especially when the electrolytic cells employ PEM (proton exchange membrane) water electrolysis or, optionally, alkaline water electrolysis, or similar components.

[0062] In this embodiment, the wind power generation device 1 preferably does not have a grid connection or grid coupling, but instead directly supplies power to the electrolysis equipment 5 using the absorbed wind energy within an autonomously operating offshore electrolysis system 100. The electrolysis equipment is configured to produce, preferably, green hydrogen, from water electrolysis. Therefore, the offshore electrolysis system 100 is configured for isolated island operation independent of the power grid and is suitable for autonomous operation far from the coast. The wind power generation device 1 is thus an offshore wind turbine.

[0063] The strategy of supplying electrolysis equipment 5 in multiple containers 9, preferably ISO containers, advantageously ensures a simple maintenance and repair process, while protecting equipment components from the effects of climate and weather, as well as corrosion and harmful mechanical effects during operation.

[0064] To operate the marine electrolysis system 100 with water electrolysis, a sufficient quantity of fully desalinated water of high purity, known as VE water, is required. This water must be continuously replenished to the process water circulation of the electrolysis unit 5 due to consumption. Typically, only saline seawater can be supplied to this marine electrolysis unit 100. However, in order to use water taken from the ocean, the seawater must be desalinated. Various desalination methods can be used for this purpose, such as reverse osmosis or vacuum distillation, but these methods all consume a large amount of electrical energy. Using electrical energy for desalination significantly reduces the efficiency of the entire unit and should therefore be minimized.

[0065] The present invention overcomes this drawback by means of a water supply device 7, which is advantageously integrated into or connected to the electrolysis system 100, for example. Thus, it is possible to... Figure 1 The water supply device 7 is at least partially housed in a selected container 9 of the offshore electrolysis system 100, as illustrated only schematically. Alternatively, a container 9 may have specific equipment components or functional elements of the water supply device 7. The water supply device 7 is coupled to the electrolysis equipment 5 and configured such that high-quality water can be supplied to the electrolysis equipment 5 without relying on the use of seawater, thus enabling continuous electrolysis operation. Rainfall, particularly rainwater, is used here, and condensate is used alternatively or additionally. Water is collected or obtained at the installation location of the offshore electrolysis system 100 or in its immediate vicinity and is treated.

[0066] The process of obtaining water without relying on seawater and the functional components of the water supply device 7 will be explained below with the aid of Figure 2The process is illustrated using a flowchart as an example. The water supply device 7 has a water collector 13, which is designed to collect precipitation or condensate from the air L. The water collector 13 is configured as a precipitation collector 41 or a condensation device 43, and combinations of these embodiments are also possible. A sufficiently large temporary storage section 15 is connected downstream of the water collector 13, where the collected water H2O can be introduced and stored. This forms a water reservoir, and the water collector 13 can be continuously or periodically emptied. For this purpose, the water collector 13 is connected to the temporary storage section 15 and, if necessary, is provided with a conveying device, such as a pump or valve, so that the collected water H2O can be conveyed to the temporary storage section 15. If the installation of the water collector 13 allows due to a set height difference, water H2O can also be autonomously introduced from the water collector 13 into the temporary storage section 15. A purification device 11 is arranged downstream of the temporary storage section 15 via an extraction pipe 17. The purification device 11 has elements and structures for water purification and treatment, such as filters and desalination devices. In this way, impurities in the collected water H2O can be removed, and residual salt can be removed. Since the quality and purity of the water H2O collected through precipitation or condensation are already high, the size of the desalination device is significantly smaller than that used in seawater desalination. Desalination work is significantly less strenuous than in seawater desalination, and the equipment costs for installation and the energy requirements for operating the purification device 11 are correspondingly reduced. These savings can be directly used as electrical power for electrolysis purposes. The purification device 11 is connected to a storage container 39 via a storage line 21. The storage container 39 can store and store fully desalinated water H2O, also known as VE water or demineralized water. This water H2O has the required high quality and purity so that it can be provided in the storage container 39 as reactant water 23 for water electrolysis. During operation of the electrolysis unit 5, the reactant water 23 obtained from precipitation or condensation is transported to the electrolysis unit 5 via an input line 37 and introduced into the electrolytic cell. A diaphragm 45 or partition separates the anode chamber 47 from the cathode chamber 49. The reactant water 23 can thus be electrochemically decomposed, resulting in the formation of oxygen (O2) on the anode side and hydrogen (H2) on the cathode side. Hydrogen (H2) is the desired product gas in the electrolysis. The hydrogen is compressed, temporarily stored if necessary, and transported to land via pipelines or transport ships.

[0067] Figure 3 A schematic side view of an offshore electrolysis system 100 is shown, comprising a wind power generation unit 1, a platform 3, and an electrolysis unit 5 arranged on the platform 3. The platform 3 is fixed to a tower 19 in a water area 29 above sea level 25. The electrolysis unit 5 comprises multiple containers 9, each containing at least one electrolysis cell. The offshore electrolysis system 100 shown here is advantageously equipped with an integrated water supply unit 7, which is shown only partially here. For details regarding the functional components, please refer to [reference needed]. Figure 2Here, the water supply device 7 has a temporary storage section 15, so that water can be drawn from the water collector 13 (see...) Figure 2 The H2O obtained from precipitation or condensation can first be stored in the temporary storage unit 15, and when needed, it can be treated and supplied to the electrolysis unit 5 for electrolysis purposes, where electrochemical conversion takes place. Condensation units 43 are arranged in the pod of the wind turbine 1 and at least in one container 9. The condensation units 43 are designed as condenser dryers. Alternatively, the condensation units 43 can be arranged in the tower 19 of the wind turbine 1. After purification and water treatment, the fully desalinated H2O is supplied to a storage container 39 specifically designed and configured for this purpose, where it is used as high-quality reactant water 23 for the electrolysis process. The water supply unit 7 is arranged in individual components on the platform 3 or in the tower 19, and can also be arranged together with the mechanism of the electrolysis unit 5 (e.g., the electrolytic cell) in one of the containers 9. The tower 19 extends from the above-water area 29 to the underwater area 31 and is securely anchored to the seabed 35 via the base 33.

[0068] The temporary storage unit 15 and the storage container 39 are designed in container form, for example, in the form of a pipe lined with metal or a low-diffusion plastic material. The temporary storage unit 15 and the storage container 39 containing the reactant water 23 are suspended and fixed below the platform 3, thus not occupying the structural space of the platform 3 itself. Furthermore, a chamber is constructed within the tower 19 of the wind power generation unit 1 (in this embodiment, this chamber is machined deep below sea level 25 within the base 33) and this chamber has a corresponding storage volume for high-quality reactant water 23. A pressure-resistant, waterproof, and diffusion-resistant storage container 39 is installed in this chamber. Thus, during the operation of the offshore electrolysis system 100, high-purity reactant water 23 can be stored in the storage container 39, and the storage container can be loaded with reactant water 23. Storage into the storage container 39 is achieved through the storage pipeline 21 or a corresponding branch pipeline on the output side of the purification device 11 (not shown in detail, but can also be found in [reference]). Figure 2 This is achieved through a connection unit installed on platform 3, which connects to a pipeline 51 for outputting hydrogen (H2) as a product gas from electrolysis. This connection unit is connected to or supplied via the product gas pipeline. Pipeline 51 is guided away from platform 3, submerged in underwater area 31, and guided along the seabed 35 to land. On land, the product gas hydrogen (H2) can be received and further processed. During normal operation of the electrolysis system 100, the product gas (hydrogen (H2) in this embodiment) can be input into pipeline 51 under pipeline pressure and transported to land. Reactant water 23 is extracted from storage container 39 via extraction pipeline 37, which is connected to electrolysis equipment 5, and supplies fully desalinated water (H2O) to the electrolyzer, which is obtained independently of seawater from precipitation or condensate.

[0069] Figure 4 The simplified illustration shows an offshore electrolysis system 100, whose water collector 13 is configured as a rainwater collector 41 and connected to the platform 3 via a water pipe 55. Rainwater collector 41 (in...) Figure 4 The water tank 53, located on the left side of platform 3, is a floating pool with a large circular collection surface. The pool 53 is floating on the water surface at a height of 25 meters above sea level and is anchored to the seabed 35 by ropes, with a base 33 for each rope on the seabed 35. Rainwater collected in the pool 53 can be pumped via water pipes 55 to a temporary storage unit 15 at platform 3 or to a temporary storage unit 15 located elsewhere.

[0070] Furthermore, the rainwater collector 41 can be arranged and fixedly installed on a supply platform 57 specifically designed for this purpose at sea. A temporary storage unit 15, and other functional components or auxiliary systems of the water supply device 7, can be installed on or below the supply platform 57, as well as if necessary. This... Figure 4 The image is exemplarily shown on the right side of platform 3. Water pipe 55 is directed to platform 3 so that rainwater collected in water collector 13 can be directed to an interface on platform 3, particularly for subsequent water treatment processes.

[0071] In another embodiment, Figure 5 A simplified illustration shows a condensation device 43 configured as a mist collector. Figure 3 Unlike the condenser unit 43 discussed herein, which has an electrically operated condenser dryer that can be locally positioned within the installation space, this mist collector has a large surface area and is permanently exposed to the external marine ambient air L. Since it requires a larger collection surface area than a condenser dryer, it is preferable to install multiple mist collectors on a specially provided supply platform 57, such as... Figure 5 As shown. (In addition) Figure 5 (Not shown in detail) The mist collector can also be deployed on the platform 3 carrying the container 9 with the electrolysis equipment 5, so as to make the best use of the existing structural space for constructing a condensation device 43 as an auxiliary collector to obtain condensate from the ambient air L.

[0072] The mist collector has a corresponding drain pipe 59 in the lower region, so that water droplets condensed from the flowing air L on the mist collector are automatically collected in the drain pipe 59 in the lower region by the slope. The drain pipe 59 of each mist collector leads to a central collection pipe 61 for collecting condensate. The collection pipe 61 is connected to a temporary storage section 15 installed on the supply platform 57. A water pipe 55 leads out from the temporary storage section 15 and leads to a purification device 11 (not shown in detail). The purification device 11 for condensate H2O can be installed, for example, in one of the containers 9 on the platform 3 carrying the electrolysis equipment 5, or arranged in one of the containers 9 containing the mechanisms and other control devices for the power plant auxiliary system 27 (see also...). Figure 1 ).

[0073] Large-area fog collectors made of nylon or polypropylene mesh, with filament diameters of 0.1 mm and mesh sizes of 1 mm, can be used on supply platform 57. In marine areas, the average fog harvesting rate is 3–9 liters / (m²·day) or even higher. The most efficient fog harvesting rates occur in spring and summer. This technology is characterized by its simple implementation, use, and maintenance, thereby limiting installation and maintenance costs. Suitable materials for fog collectors are textiles with different mesh sizes and fabric forms, such as dotted structures, porous structures, and honeycomb structures. Here, according to the wetting characteristics of the fog droplets, they can be classified as: hydrophobic, i.e., hydrophobic with a large contact angle between the water droplet and the fabric (lotus effect); and hydrophilic, i.e., hydrophilic with high wettability and a small contact angle with the fabric. The physical process of moisture absorption and re-drainage is explained as follows: fine fog droplets adhere to the fabric and continuously converge and grow larger due to the continuous arrival of fog droplets until they reach a size that allows water droplets to flow down.

Claims

1. An offshore electrolysis system (100) comprising a wind power generation unit (1) having a platform (3) and an electrolysis device (5) disposed on the platform (3), the wind power generation unit (1) being connected to the electrolysis device to supply electrolysis current, the offshore electrolysis system further comprising a water supply device (7) connected to the electrolysis device (5), the water supply device having a water collector (13) configured to obtain water that is saline-free or contains only a very small amount of salt without relying on seawater, the water being usable as reactant water for operating the electrolysis device (5).

2. The marine electrolysis system (100) according to claim 1, characterized in that, The water supply device has a temporary storage section (15), which is disposed on the platform (3) and / or installed in the tower (19) of the wind power generation device (1), wherein the temporary storage section (15) is connected to the water collector (13).

3. The marine electrolysis system (100) according to claim 2, characterized in that, A purification device (11) is provided, which is connected to the temporary storage unit (15) via an extraction pipe (17).

4. The marine electrolysis system (100) according to claim 3, characterized in that, The purification device (11) is connected to the storage container (39) via the storage pipeline (21), thereby enabling the treated water to be delivered to the storage container (39) as reactant water (23) and prepared for operation of the electrolysis equipment (5).

5. The marine electrolysis system (100) according to claim 4, characterized in that, The storage container (39) is connected to the electrolysis equipment (5) via an input pipe (37).

6. The marine electrolysis system (100) according to any one of the preceding claims, characterized in that, The water collector (13) has a rainwater collector (41) which is configured to collect rainwater.

7. The marine electrolysis system (100) according to claim 6, characterized in that, The precipitation collector (41) has a pool, which is fixed on the platform (3) and / or floated on the sea surface.

8. The marine electrolysis system (100) according to any one of the preceding claims, characterized in that, The water collector (13) has a condensation device (43) configured to condense saturated humid air.

9. The marine electrolysis system (100) according to claim 8, characterized in that, The marine electrolysis system has a condensation device (43) with a fog collector, which has a fine-mesh, large-area net as a collector, particularly a nylon net or a polypropylene net.

10. The marine electrolysis system (100) according to claim 8, characterized in that, The condensation device (43) has a condensation dryer, wherein the condensation dryer is arranged in the tower (19) or pod of the wind power generation device (1).

11. The marine electrolysis system (100) according to claim 9 or 10, characterized in that, The electrolysis equipment (5) includes an electrolytic cell and a condensation device (43) arranged in a container (9), thereby enabling the condensation of moisture in the container (9) and creating dry operating conditions.

12. A marine electrolysis system (100), characterized in that, The offshore electrolysis system achieves an isolated power grid that is not connected to the power grid.

13. The marine electrolysis system (100) according to any one of the preceding claims, characterized in that, The electrolysis equipment (5) includes an electrolytic cell for water electrolysis, which is based on proton exchange membrane (PEM) electrolysis or alkaline electrolysis and uses hydrogen (H2) as the product gas.

14. A method of operating the marine electrolysis system (100) according to any one of the preceding claims, wherein, Water of a certain quality is obtained in the water collector (13) without relying on seawater, and the water obtained therein contains no salt or only a very small amount of salt.

15. The method according to claim 14, characterized in that, Collect precipitation and / or extract water from condensed saturated moist air.

16. The method according to claim 14 or 15, characterized in that, The obtained water is processed and the processed water is delivered to the electrolysis equipment (5) as reactant water (23).

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