Method and system for providing gaseous compressed oxygen

Abstract

The invention relates to a method (100, 200) for providing high-pressure oxygen (H) using low-pressure oxygen (L) containing water, in which method the low-pressure oxygen (L) is subjected to a drying process (30) and subsequently to a pressure increase (40, 50), the drying process (30) comprising an adsorption step. In the adsorption step, a regeneration gas (R) is used which is provided using oxygen that is provided using the pressure increase (40, 50) and using at least part of the low-pressure oxygen (L). The pressure increase (40) is performed above 0°C and using a plurality of compressors or compressor stages (41, 42, 43) which have an intercooler (44) between two compressors and / or compressor stages (41, 42). At least part of the oxygen which is used to form the regeneration gas (R) is removed from the pressure increase (40) between two of the compressors or compressor stages (41, 42) upstream of the intercooler (44). Alternatively, the pressure increase is carried out by means of internal compression. The invention also relates to a corresponding system.

Description

[0001] Description

[0002] Process and system for the provision of gaseous compressed oxygen

[0003] The invention relates to a method and a plant for providing gaseous compressed oxygen, in particular using electrolysis.

[0004] Background of the invention

[0005] Oxygen can be produced by water electrolysis, especially as a secondary product alongside hydrogen. For information on water electrolysis, please refer to relevant literature, for example, the article "Hydrogen" in Ullmann's Encyclopedia of Industrial Chemistry, Wiley-VCH, June 15, 2000, DOI: 10.1002 / 14356007.a13_297, especially Section 4.2, "Electrolysis."

[0006] In certain electrolysis processes, oxygen is produced at a lower pressure than desired during water electrolysis. For example, many applications require oxygen at a pressure of 30 or 60 bar (absolute), which is why oxygen must be compressed in these cases. Compression, in turn, typically requires the removal of water.

[0007] The present invention has for its object to improve the compression of oxygen, in particular of water-containing oxygen from water electrolysis, compared to the prior art.

[0008] Disclosure of the invention

[0009] This object is achieved by a method and a system for producing gaseous compressed oxygen, in particular using electrolysis, having the features of the independent patent claims. The dependent patent claims and the following description specify embodiments.

[0010] In conventional water electrolysis, an aqueous alkaline solution, typically potassium hydroxide, is used as the electrolyte (AEL, alkaline electrolysis). The electrolysis, which is carried out using a unipolar or bipolar electrode arrangement, takes place at atmospheric pressure or, on an industrial scale, significantly higher. In appropriate cases, subsequent compression may even be omitted.

[0011] Recent developments in water electrolysis include the use of proton-conducting ion exchange membranes (SPE, Solid Polymer Electrolysis; PEM, Proton Exchange Membranes), in which the water to be electrolyzed is supplied at the anode side. Electrolysis technologies using an anion exchange membrane (AEM) are also being used. In such processes, especially PEM, oxygen is produced at a lower pressure and therefore, as mentioned above, must be compressed if it is required at a correspondingly higher pressure.

[0012] The water electrolysis processes mentioned so far are low-temperature processes in which the water to be electrolyzed is in the liquid phase. So-called steam electrolysis is also used, which can also be carried out with alkaline electrolytes (i.e., AELs) with adapted membranes, such as polysulfone membranes, or using solid oxide electrolysis cells (SOECs). The latter include, in particular, doped zirconium dioxide or oxides of other rare earth elements, which become conductive at higher temperatures.

[0013] The term "electrolysis" will be used below to encompass all of these processes. Low-temperature electrolysis (PEM, AEL, AEM) is particularly suitable for flexible operation, supporting the energy transition to renewable energies. All processes can be used in embodiments of the invention.

[0014] During water electrolysis, oxygen is typically produced with a certain (residual) water content; the produced oxygen is water-saturated (depending on temperature and pressure). Another source of water can also arise from the catalytic conversion of (residual) hydrogen. In the following, the term "oxygen" should therefore be understood not only to mean pure oxygen, but also an oxygen-rich gas mixture with an oxygen content of, for example, more than 90%, 95% or 99% and in particular with a water content of typically 1% to 5% or more. As already mentioned, the oxygen is water-saturated and thus the water content in the oxygen depends on pressure and temperature. The water content can therefore be determined using common calculation methods. All percentages used above and below refer to mass, volume or mole percent.

[0015] In principle, embodiments of the present invention are not limited to the processing of electrolysis oxygen from water electrolysis, but can be used with oxygen, in particular of the composition just mentioned, from all conceivable sources.

[0016] The oxygen can be compressed using oxygen compressors (e.g., piston compressors), as is also possible in embodiments of the invention. However, these can only be operated with essentially anhydrous feed gas. Cryogenic liquefaction, purification, or compression, as is also possible in further embodiments of the invention, also requires anhydrous feed gas, since water could freeze and block the heat exchangers used. Conventional processes have the disadvantage that the drying processes used significantly reduce the oxygen yield.

[0017] Against this background, the present invention proposes a process for producing gaseous high-pressure oxygen using water-containing, gaseous low-pressure oxygen, in which the low-pressure oxygen is subjected to drying and then a pressure increase, wherein the drying comprises an adsorption step which can be carried out in particular as temperature or pressure swing adsorption. It is provided that a regeneration gas is used in the adsorption, which is provided using oxygen which is provided by using the pressure increase and using at least a portion of the low-pressure oxygen. After its use in the adsorption step, in which it was loaded with water, the regeneration gas can, in embodiments of the invention, be subsequently recycled back into the process, in particular upstream of the drying step.

[0018] The term "regenerating gas" refers to a gas used in the regeneration of an adsorbent used in an adsorption system or an adsorption step. Temperature swing adsorption involves a gas or gas mixture that is passed over the loaded adsorbent at elevated temperature and absorbs the desorbed components. Pressure swing adsorption involves the gas or gas mixture used to flush the desorbed components from the adsorbent after the pressure reduction required for regeneration. The composition after such use can be similar or identical in both cases.

[0019] In particular, a combination with fresh, hydrous oxygen can take place. In this case, condensative water separation can take place upstream of the drying process and downstream or upstream of the combination, upstream of which, in particular, cooling can take place. The condensative water separation upstream of the combination can take place in particular if no hydrogen is removed. In this case, it can be provided to only cool the regeneration gas and then remove the water in a water separator. In particular, this recycling can increase the oxygen yield in embodiments of the invention. Separated water can, for example, be reused in an electrolysis process, if required. Embodiments of the invention provide a significantly more cost-effective option for producing (high-)pressure oxygen, in particular from an electrolysis process, compared to the prior art.

[0020] Embodiments of the invention may, in particular, include carrying out the regeneration at a higher pressure than the adsorption in the adsorption step. The regeneration gas may, in particular, be heated. To prevent an accumulation of, for example, carbon dioxide or other gases in the circuit, a partial purge or discharge from the process may also be carried out.

[0021] In embodiments of the invention, a water-laden regeneration gas formed during regeneration in the adsorption step can therefore be subjected to condensation to obtain an aqueous condensate fraction, in which case water cooling can be used in particular. More generally, water contained in the regeneration gas after its use in the adsorption step can be at least partially recycled to the process.

[0022] In embodiments of the invention, the condensate fraction can be fed, without or after treatment, for example, to water electrolysis, using which the low-pressure oxygen is formed. In one embodiment of the invention, treatment can in particular comprise a thermal expulsion of gases, in particular argon and / or carbon dioxide, from the water, to which fresh water supplied to the electrolysis is also subjected. In this case, for example, a content of 5 to 10 ppm argon in the fresh water can be reduced to a content of less than 1 ppm, in particular less than 10 or 1 ppb, more particularly less than 0.1 ppb.

[0023] As is usual with electrolysis using a proton exchange membrane, the treatment can also be preceded by demineralization, which removes interfering ions that can arise, in particular, from the materials used in oxygen treatment.

[0024] In embodiments of the invention, the low-pressure oxygen is provided at a pressure in a first pressure range, the high-pressure oxygen is provided at a pressure in a second pressure range above the first pressure range, and the oxygen used to form the regeneration gas is provided using the pressure increase at a pressure in a third pressure range between the first and second pressure ranges or in the second pressure range. The pressure in the first pressure range corresponds in particular to the adsorption pressure in the adsorption step, and the pressure in the third pressure range corresponds in particular to the regeneration pressure, as explained.

[0025] The person skilled in the art selects the pressure ranges appropriately. The pressure range for regeneration, i.e. the third pressure range, lies above the pressure of the oxygen to be regenerated, i.e. the pressure in the first pressure range, and is adjusted so that the laden regeneration gas stream has sufficient pressure to be recirculated. It lies at least 200 mbar above the first pressure range. In embodiments of the invention, at least a portion of the oxygen used to form the regeneration gas can be taken from the pressure increase to the pressure in a third pressure range, or at least a portion of the oxygen used to form the regeneration gas can be taken from the pressure increase to a pressure in a fourth pressure range above the third pressure range and expanded to the pressure in the third pressure range.

[0026] In a first group of embodiments of the present invention, the pressure increase can be carried out above 0 °C and using a plurality of compressors or compressor stages, in particular a plurality of turbo compressors or turbo compressor stages or piston compressors or piston compressor stages.

[0027] Embodiments of the invention enable an advantageous reduction of the water content, which is required for compression in such compressors or compressor stages.

[0028] In embodiments of the present invention belonging to the aforementioned first group of embodiments, at least a portion of the oxygen used to form the regeneration gas can be extracted from the pressure increase between two of the compressors or compressor stages. In particular, extraction and, if necessary, throttling to a suitable pressure can occur. Extraction can occur, in particular, upstream and / or downstream of an intercooler provided between the two compressor stages. Particularly when using temperature swing adsorption in the adsorption step, a warm exhaust between compressor stages (upstream of the intercooler) is advantageous because in this way the compression heat can be used for regeneration and the regeneration energy requirement can be reduced. Extraction downstream of an intercooler can occur in order to form a regeneration gas stream for a cooling step in the temperature swing adsorption.The regeneration gas can therefore be withdrawn in particular during a heating phase in the adsorption step upstream of the intercooler and during the cooling phase in the adsorption step downstream of the intercooler.

[0029] In a second group of embodiments of the present invention, however, the pressure increase can comprise cryogenically liquefying at least a portion of the low-pressure oxygen subjected to drying and subsequent pressure increase to obtain a cryogenic liquid, pressurizing at least a portion of the cryogenic liquid in the liquid state to obtain a pressurized cryogenic liquid, and converting at least a portion of the cryogenic and pressurized cryogenic liquid into the gaseous or supercritical state. The pressure increase can be performed in a manner comparable to "internal compression," as is generally known from the field of cryogenic air separation. Internal compression is explained, for example, in H.-W. Häring (ed.), Industrial Gases Processing, Wiley-VCH, 2006, in Section 2.2.5.2, "Internal Compression." It offers particular safety-related advantages.The pressure increase can be achieved by means of a pump or so-called run tanks, i.e. by means of pressure build-up evaporation, as described in particular in WO 2021 / 129948 A1.

[0030] In embodiments of the present invention belonging to the aforementioned second group of embodiments, cryogenic liquefaction can be carried out, in particular, using a heat exchanger operated with a nitrogen refrigeration circuit. For example, existing or externally supplied nitrogen can be used.

[0031] In embodiments of the present invention belonging to the aforementioned first group of embodiments, a portion of the pressurized cryogenic liquid and at least a portion of the oxygen used to form the regeneration gas can be heated in the heat exchanger. This enables particularly advantageous heat recovery.

[0032] Although previously a first and a second group of configurations were mentioned, it is understood that the configurations and partial aspects thereof can also be combined with each other.

[0033] Embodiments of the invention can comprise intermediate storage of the cryogenic liquid in a liquid storage device, which can be carried out in particular in certain operating modes. This enables particularly advantageous adaptation to the respective electricity supply and the respective electricity price. For example, in a first operating mode at low energy prices, an excess of oxygen can be generated in an electrolysis process, and this excess and / or liquid nitrogen can be stored in a tank. In a second operating mode, however, enough oxygen is generated to cover the demand for high-pressure oxygen and not exceed it. There is no storage in or withdrawal from the tank.In a third operating mode during periods of high electricity prices, however, a smaller amount of oxygen, or no oxygen at all, can be produced through electrolysis, and instead the demand for high-pressure oxygen can be met at least partially from the liquid storage facility. In particular, when using liquid nitrogen, a gas storage facility can be used.

[0034] In all of the embodiments explained, the low-pressure oxygen can be provided using electrolysis oxygen, which is provided using electrolysis. At least a portion of the electrolysis oxygen can be provided as hydrogen-containing electrolysis oxygen, wherein the hydrogen is at least partially converted to water using catalytic hydrogen removal, followed by cooling and water separation, and wherein the water (still present after water separation) is at least partially removed during drying. In particular, a heat exchanger can be connected upstream of the catalytic hydrogen removal, which heats the low-pressure oxygen to a temperature at least 15°C above the dew point and which is in particular driven predominantly or exclusively by electricity.Embodiments of the present invention are particularly suitable for use with corresponding electrolysis processes, since the oxygen is formed as hydrous oxygen. For the reasons explained above, particular advantages arise in conjunction with electrolysis carried out using a proton exchange membrane.

[0035] A plant for providing high-pressure oxygen using water-containing low-pressure oxygen, which plant is configured to subject the low-pressure oxygen to drying and subsequent pressure increase, and to carry out the drying using an adsorption step, is also subject to the present invention. This plant is configured to use a regeneration gas in the adsorption step, to form the regeneration gas using oxygen, and to provide the oxygen used to form the regeneration gas using the pressure increase and using at least a portion of the low-pressure oxygen.

[0036] With regard to the features and advantages of the system provided according to the invention and its embodiments, reference is expressly made to the features and advantages explained above with regard to the method according to the invention and its embodiments. This also applies to a system according to a particularly preferred embodiment of the present invention, which is designed to carry out a method as explained above or a corresponding embodiment thereof.

[0037] In all embodiments of the present invention, it can be provided that the adsorption step, in particular a temperature swing adsorption, is preceded by cooling, in particular with a cooling medium that is colder than the normal process cooling water (e.g. so-called chilled water of a refrigeration system) and a water separation in order to achieve a reduction in the water content and in this way to relieve the adsorption step accordingly.

[0038] All embodiments of the present invention can comprise a first operating phase and a second operating phase, wherein oxygen production, i.e., the amount of low-pressure oxygen provided, is lower in the second operating phase than in the first operating phase (so-called turndown mode). The electrolysis is deactivated or operated at lower power during the second operating phase. To ensure good flow through the catalytic reactor for hydrogen removal, a minimum amount of gas must be passed through it. This strongly influences the size of the catalytic bed and, under full load, increases the pressure drop of the catalytic reactor.Therefore, in corresponding embodiments of the invention, it can be provided that the regeneration gas stream, after its use in the adsorption step, is recycled upstream of the catalytic hydrogen removal in the second operating mode in order to ensure good flow there and reduce the pressure drop at full load (since the reactor can be designed sufficiently large and with a small pressure drop). In the first operating mode, the recycling can take place downstream of the catalytic hydrogen removal. Mixed forms are also possible. The low-pressure oxygen can be supplied to the adsorption step with or without a further temperature increase (the temperature increase during oxygen compression may already be sufficient, and a further temperature increase, e.g., an electric heater, can be dispensed with.

[0039] The invention will be further explained below with reference to the accompanying drawings, which illustrate embodiments of the present invention.

[0040] Short description of the drawings

[0041] Figure 1 shows a method according to an embodiment of the invention.

[0042] Figure 2 shows a method according to an embodiment of the invention.

[0043] Figure 3 shows a water return according to an embodiment of the invention.

[0044] Figure 4 shows a cryogenic densification according to an embodiment of the invention.

[0045] In the figures, structurally and / or functionally equivalent components, as well as identical or comparable material flows, are indicated with identical reference symbols and are not explained repeatedly for the sake of clarity. Explanations regarding process steps also refer to corresponding devices or components of plants, and vice versa.

[0046] Detailed description of the drawings

[0047] Figure 1 shows a method 100 according to an embodiment of the invention in the form of a schematic process flow diagram.

[0048] In the process 100, electrolysis oxygen E still containing certain amounts of hydrogen, in particular with a content of more than 98%, is produced using an electrolysis 10, for example using a proton exchange membrane. The electrolysis oxygen E can be vented in an emergency via a line 11 with a safety valve. A hydrogen removal line is designated overall by 20. It comprises, for example, an electric heater 21, with which a temperature delta of, for example, 25 °C can be operated. The correspondingly heated oxygen is fed to a catalytic bed in a reactor 22, in which hydrogen is converted to water. After combining with a water-laden regeneration gas stream R, the water-containing oxygen is cooled in a cooler 23, which is operated, for example, with cooling water, and subjected to condensate separation in a condensate separator 24.A water flow W formed here can be recirculated, as illustrated in detail in Figure 3.

[0049] Oxygen partially freed of water in this way, however, still contains a certain amount of water. It is referred to here as gaseous low-pressure oxygen and is illustrated by the reference symbol L. It is subjected to drying, designated overall by 30, using temperature swing adsorption. In the drying process 30, a pair of adsorbers 31, 32 operated alternately is used. These are operated, for example, at an adsorption pressure of 4.5 bar and a regeneration pressure of 5 bar. Instead of temperature swing adsorption, pressure swing adsorption can also be carried out, as is generally known to those skilled in the art and therefore not illustrated separately. Any reference to temperature swing adsorption below is not intended to be limiting.The low-pressure oxygen, which has been freed from water in this way and is still designated L, is then subjected to a total pressure increase designated 40.

[0050] In the example illustrated here, three compressors or compressor stages 41, 42, 43 are used for pressure boosting, downstream of which intercoolers or aftercoolers 44, 45, 46 can be arranged. Pressure booster 40 produces compressed oxygen H and removes it from the process.

[0051] In the example illustrated here, regeneration gas R is withdrawn between the compressors or compressor stages 41, 42 and throttled as needed via valves not specifically designated, before being heated to an adjustable extent in an electric heater 33 and passed through the respective adsorber 31, 32 to be regenerated. An initial temperature of the regeneration gas can be adjusted by adjusting the amounts withdrawn upstream and downstream of the intercooler 44. Portions of the regeneration gas can be released to atmosphere A before or after use for regeneration.

[0052] Embodiments of the invention provide, in particular, a return in the manner already explained above, ie, upstream of the cooling in the cooler 23. Additional or alternative return options are shown in dashed lines and are illustrated upstream and downstream of the heater 21.

[0053] Figure 2 shows a method 200 according to an embodiment of the invention, in which, in contrast to the method 100 illustrated in Figure 1, a cryogenic pressure increase 50 is carried out in the manner explained. For further details, reference is made in particular to the explanations for Figure 4.

[0054] Figure 3 shows aspects of a method according to an embodiment of the invention in an alternative representation, particularly illustrating a water recirculation. The method steps and system components explained in Figure 3 can be used in any of the previously explained embodiments.

[0055] As illustrated here, a fresh water stream F is fed to a water treatment system 60. The water treatment system 60 can be configured in any desired manner, and a condensate stream C formed as explained below can also be fed to it, which condensate stream C can in particular be combined with the fresh water stream F. A pure water stream P formed in the water treatment system 60 can in particular be cooled and a portion of which can be fed into the electrolysis system 10.

[0056] Electrolysis 10 generates the aforementioned electrolysis oxygen stream E, which is fed to the catalytic hydrogen removal 20 and drying 30 illustrated here in combination. Reference is made to the above explanations. Low-pressure oxygen L discharged from the catalytic hydrogen removal 20 and drying 30 is subjected to pressure increase 40 or 50 to obtain high-pressure oxygen H, as already explained for Figures 1 and 2 as well as Figure 4. A hydrogen stream is designated X.

[0057] The regeneration gas R previously used in the temperature swing adsorption or drying 30 is cooled in a cooler, designated here by 65, for example with cooling water, and fed into a separator 66, where a condensate phase separates. This can be recirculated to the water treatment 60 in the form of condensate stream C as explained above. A gas fraction from the separator 66 consists essentially of water-containing oxygen. It can be recirculated in the form of stream O, as explained above. As an alternative to the treatment of the condensate stream C, direct recirculation is also possible, as illustrated by a dashed arrow.

[0058] Figure 4 shows a cryogenic compression system 50 according to one embodiment of the invention. Here, the low-pressure oxygen L is supplied to a heat exchanger 51 on the warm side and removed from the heat exchanger on the cold side. The heat exchanger 51 is operated with a nitrogen circuit 52. A liquid storage device 53 is optionally provided. The low-pressure oxygen L, which is removed essentially in liquid form or in the form of a two-phase flow due to cooling, is fed into a separator 54, where a cryogenic liquid separates. The cryogenic liquid is pressurized in the form of a material flow K by means of a pump 55 or by means of a pressure build-up evaporator 55. To provide the regeneration gas R, a portion of this can be throttled off; the remainder forms the high-pressure oxygen flow H. These oxygen flows and a gas flow Y from the top of the separator 54, if liquid, are evaporated in the heat exchanger or converted to the supercritical state.The liquid storage 53 can be used in the manner explained above.

[0059] The nitrogen circuit 52 can be fed with gaseous nitrogen in the form of a nitrogen stream 501. Together with gaseous or re-evaporated nitrogen streams 502, 503 heated in the heat exchanger 51, this nitrogen is compressed in a circuit compressor 504 and aftercooled in a not separately designated aftercooler. A partial stream 505 is cooled to the pressure thus achieved in the heat exchanger 51, at least partially liquefied therein, removed from the cold side, and fed into a separator 510.A further portion 506 is further pressure-increased in a booster 507, further cooled in an aftercooler (not specifically designated), and then cooled to the pressure thus reached in the heat exchanger 51. A partial stream 508 is withdrawn from the heat exchanger 51 at an intermediate temperature, expanded in a turbine 509 coupled to the booster 507, and fed into the separator 510. A partial stream 511 is withdrawn from the cold side of the heat exchanger 51 and also fed into the separator 510. The partial streams 508 and 511 are also at least partially liquefied in the previous steps.

[0060] Gas from the top of the separator 510 forms the aforementioned material stream 503. Liquid from the sump is partially re-evaporated in the heat exchanger 51 to form material stream 502. In the case of excess, liquid nitrogen can be fed into a liquid storage tank 514 in the form of a material stream 513. After the initial filling of the nitrogen circuit 52, it can be operated autonomously.

Claims

Patent claims 1. A method (100, 200) for providing high-pressure oxygen (H) using low-pressure oxygen (L) containing water, wherein the low-pressure oxygen (L) is subjected to drying (30) and subsequently to pressure increase (40, 50), the drying (30) comprising an adsorption step, characterized in that a regeneration gas (R) is used in the adsorption step, which is provided using oxygen provided by the pressure increase (40, 50) and using at least a portion of the low-pressure oxygen (L), wherein the pressure increase (40) is carried out above 0 °C and using several compressors or compressor stages (41, 42, 43) which have an intercooler (44) between two compressors and / or compressor stages (41, 42), and wherein at least a portion of the oxygen used to form the regeneration gas (R)The pressure increase (40) is taken from between two of the compressors or compressor stages (41, 42) upstream of the intercooler (44).

2. The method of claim 1, wherein the adsorption step comprises temperature swing adsorption and / or pressure swing adsorption.

3. Method (100, 200) according to claim 1 or 2, wherein the regeneration gas is at least partially recycled back into the method (100, 200) after its use in the temperature swing adsorption.

4. Method (100, 200) according to claim 3, wherein water contained in the regeneration gas after its use in temperature swing adsorption is at least partially recycled into the method (100, 200).

5. Method (100, 200) according to one of the preceding claims, wherein the low-pressure oxygen (L) is provided at a pressure in a first pressure range, the high-pressure oxygen (H) is provided at a pressure in a second pressure range above the first pressure range, and the oxygen used to form the regeneration gas (R) is provided at a pressure in a third pressure range by means of the pressure increase (40, 50). between the first and second printing areas, in the second printing area.

6. Method (100) according to one of the preceding claims, wherein the regeneration gas (R) is withdrawn during a heating phase in the adsorption step upstream of the intercooler and during the cooling phase in the adsorption step downstream of the intercooler.

7. Method (200) for providing high-pressure oxygen (H) using low-pressure oxygen (L) containing water, wherein the low-pressure oxygen (L) is subjected to drying (30) and subsequently to pressure increase (40, 50), wherein the drying (30) comprises an adsorption step, characterized in that a regeneration gas (R) is used in the adsorption step, which is provided using oxygen provided by means of the pressure increase (40, 50) and using at least a part of the low-pressure oxygen (L), wherein the pressure increase (50) involves cryogenic liquefaction of at least a part of the low-pressure oxygen (L) subjected to drying (30) and subsequently to pressure increase (50) to obtain a cryogenic liquid, and pressurizing at least a part of the cryogenic liquid in liquid form to obtain a pressurized cryogenic liquid.and includes converting at least a portion of the cryogenic and pressurized cryogenic fluid into the gaseous or supercritical state.

8. Method (200) according to claim 7, wherein the cryogenic liquefaction is carried out using a heat exchanger (51) operated with a nitrogen refrigeration cycle (52).

9. Method (200) according to claim 8, wherein at least a part of the pressurized cryogenic liquid and at least a part of the oxygen used to form the regeneration gas (R) are heated in the heat exchanger (51). Method (200) according to any one of claims 7 to 9, comprising intermediate storage of the cryogenic liquid in a liquid storage tank (53). Method (100, 200) according to any one of the preceding claims, wherein the low-pressure oxygen (L) is provided using electrolysis oxygen (E) which is provided by means of electrolysis (10).A method (100, 200) according to claim 1, wherein at least a portion of the electrolysis oxygen (E) is provided as hydrogen-containing electrolysis oxygen (E), the hydrogen being at least partially converted to water by means of a catalytic hydrogen removal (20) followed by cooling and water separation, and wherein the water being at least partially removed in the drying (30), wherein, in particular, a heat exchanger is connected upstream of the catalytic hydrogen removal (20), which heats the low-pressure oxygen to a temperature at least 15 °C above the dew point, and which is driven, in particular, predominantly or exclusively by electricity. A method (100, 200) according to claim 1 or 12, wherein the electrolysis (10) is carried out using a proton exchange membrane and / or alkaline electrolysis.A system for providing high-pressure oxygen (H) using low-pressure oxygen (L) containing water, which is configured to subject the low-pressure oxygen (L) to drying (30) and subsequently to pressure increase (40, 50) and to carry out the drying (30) using temperature swing adsorption, characterized in that the system is configured to use a regeneration gas (R) in the temperature swing adsorption, to form the regeneration gas (R) using oxygen, and to provide the oxygen used to form the regeneration gas (R) using the pressure increase (40, 50) and using at least a part of the low-pressure oxygen (L), and wherein a device for pressure increase (40) is used which. - several compressors or compressor stages (41, 42, 43) as well as - an intercooler (44) arranged between two compressors and / or compressor stages (41, 42) - and - between two of the compressors or compressor stages (41 , 42) upstream of the intercooler (44) has a means for removing at least some of the oxygen used to form the regeneration gas (R), - wherein the device for pressure increase (40) is configured for compression above 0 °C. A system for providing high-pressure oxygen (H) using water-containing low-pressure oxygen (L), configured to subject the low-pressure oxygen (L) to drying (30) and subsequently to pressure increase (40, 50), and to carry out the drying (30) using temperature swing adsorption, characterized in that the system is configured to use a regeneration gas (R) in the temperature swing adsorption, to form the regeneration gas (R) using oxygen, and to provide the oxygen used to form the regeneration gas (R) using the pressure increase (40, 50) and using at least a portion of the low-pressure oxygen (L).wherein the pressure increase (50) comprises cryogenic liquefaction of at least a portion of the low-pressure oxygen (L) subjected to drying (30) and subsequent pressure increase (50) to obtain a cryogenic liquid, pressurization of at least a portion of the cryogenic liquid in liquid form to obtain a pressurized cryogenic liquid, and conversion of at least a portion of the cryogenic and pressurized cryogenic liquid into the gaseous or supercritical state.

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