Method and apparatus for producing hydrogen gas

Abstract

A method (100-600) for producing hydrogen gas is presented, the method comprising providing a first gas (1) containing hydrogen gas, oxygen gas and water, said providing the first gas (1) comprising electrolytic conversion of water; providing a second gas (5) containing hydrogen gas, oxygen gas and water, said providing the second gas (5) comprising condensing removal of water from the first gas (1) or a portion thereof; and providing a third gas (10) containing hydrogen gas, said providing the third gas (10) comprising adsorptive removal of water and catalytic removal of oxygen gas from the second gas (5) or a portion thereof using an adsorptive and catalytic treatment arrangement (110) comprising treatment vessels (A, B), wherein each of the treatment vessels (A, B) comprises a first adsorptive layer (211), a catalytic layer (212) and a second adsorptive layer (213) in a first direction from a first opening to a second opening, wherein each of the treatment vessels (A, B) is operated in a treatment mode and a regeneration mode alternately, wherein, in the treatment mode, the second gas (5) or a portion thereof is passed through the treatment vessels (A, B) in the first direction, wherein, in the treatment mode, the first adsorptive layer (211) and the second adsorptive layer (213) are used for said adsorptive removal of water and said catalytic layer (212) is used for said catalytic removal of oxygen gas, wherein, in the regeneration mode, the treatment vessels (A, B) are heated using a heated gas (5a, 10a) formed from the second gas (5) or a portion of the third gas (10), heated and passed through the treatment vessels (A, B). A corresponding apparatus is also provided.

Description

[0001] This disclosure relates to methods and apparatus for producing hydrogen based on water electrolysis. Technical Field

[0002] Using water electrolysis to produce hydrogen may require downstream removal of oxygen and moisture. Moisture includes residual moisture carried from the electrolysis feed and water generated during oxygen removal. Oxygen removal is typically performed by catalytically converting oxygen into hydrogen and water, a process commonly referred to in the art as DeOxo.

[0003] The goal is to improve the catalytic process for hydrogen production. Summary of the Invention

[0004] This document presents methods and apparatus including the features of the independent claims. Embodiments thereof are the subject of the independent claims and the description below.

[0005] The method for generating hydrogen as proposed herein includes: providing a first gas containing hydrogen, oxygen, and water, the provision of the first gas including the electrolytic conversion of water; providing a second gas containing hydrogen, oxygen, and water, the provision of the second gas including the condensation removal of water from the first gas or a portion thereof; and providing a third gas containing hydrogen, the provision of the third gas including the adsorption and catalytic removal of water from the second gas or a portion thereof using an adsorption and catalytic treatment arrangement including a treatment container.

[0006] In the proposed method, each processing container in the processing vessel includes a first adsorption layer, a catalytic layer, and a second adsorption layer in a first direction from a first opening to a second opening. Each processing container operates alternately in a processing mode and a regeneration mode, such that, specifically at each time point, at least one processing container is operating in the processing mode. In the processing mode, a second gas, or a portion thereof, is passed through the processing container in the first direction, wherein, in the processing mode, the first and second adsorption layers are used for the adsorption removal of water, and the catalytic layer is used for the catalytic removal of oxygen. In the regeneration mode, the processing container is heated using a heated gas formed from a portion of the second or third gas, which is heated and passes through the processing container. As explained below, depending on the specific regeneration mode and the source of the heated gas, the passage of the heated gas through the processing container can be performed in the first direction or in a second direction opposite to the first direction.

[0007] Using the method proposed herein, a separate catalytic reactor for oxygen removal can be eliminated, thus reducing operating and installation costs and process complexity. Furthermore, space requirements are significantly reduced. More efficient operation is possible because preheating is not required as in the case of a single catalytic reactor. No blower is needed for regeneration, as the “saved” pressure loss from the catalytic reactor can be used for feed gas regeneration. This also reduces maintenance of rotating equipment, which can be replaced, for example, by simple valve positioners. Oxygen removal efficiency can be improved according to the method proposed herein, since oxygen removal is possible even in regeneration mode. More efficient oxygen removal is also possible due to the near-dry conditions at the catalyst. Less water contaminated by catalyst particles is generated in the proposed method, as explained in further detail below. The method proposed herein allows for compact design and therefore allows for containerized or skid-mounted solutions for larger plants.

[0008] According to certain embodiments proposed herein, the first adsorption layer may have a volume of 50% to 80% of the total volume of the first adsorption layer, the catalyst layer, and the second adsorption layer, the catalyst layer may have a volume of 5% to 10% of the total volume, and the second adsorption layer may have a volume of 10% to 40% of the total volume.

[0009] According to certain embodiments presented herein, the first gas contains hydrogen with a first hydrogen content, water with a first water content, and oxygen with a first oxygen content; the second gas contains hydrogen with a second hydrogen content, water with a second water content, and oxygen with a second oxygen content; and the third gas contains hydrogen with a third hydrogen content. The first, second, and third hydrogen contents gradually increase from the first gas to the third gas, while a large amount of water is removed from the first gas to the second gas via condensation, and the remainder is removed adsorbently, followed by catalytic removal of oxygen. This allows for the advantageous operation discussed above.

[0010] According to certain embodiments proposed herein, the first water content is a water content above the saturation content, the second water content is a water content corresponding to the saturation content, and the third water content is 0 to 50 parts per million or 0 to 5 parts per million based on volume, and / or the first oxygen content is 50 to 1000 parts per million based on volume, the second oxygen content is 50 to 1000 parts per million based on volume, and the third oxygen content is 0 to 5 parts per million based on volume. Embodiments proposed herein allow for the acquisition of a third gas with reduced effort under more efficient conditions, which may be a hydrogen product containing particularly low levels of water and oxygen.

[0011] According to certain embodiments presented herein, the first gas is provided at an absolute pressure of 10 to 40 bar and a temperature of 50 to 70°C, the second gas is provided at an absolute pressure of 10 to 40 bar and a temperature of 5 to 60°C or 10 to 50°C, and the third gas is provided at an absolute pressure of 10 to 40 bar and a temperature of 5°C or 10 to 70°C. This implies that there is no significant pressure drop. In some embodiments, the gas temperature and pressure can be selected such that the gas in the adsorption and catalytic treatment arrangement is much higher than the condensation temperature, for example, more than 10 K and at most 20 K above the dew point. In other configurations, the gas entering the catalytic treatment arrangement can be saturated. In the latter case, the feed stream will be saturated at the temperature of the cooler and condenser upstream of the adsorber, and it is not necessary to superheat the feed stream entering the adsorber.

[0012] According to certain embodiments presented herein, the heating gas portion of the second or third gas accounts for 5% to 60% of the total volume of the second or third gas. This allows for advantageous operation as discussed above and further explained below.

[0013] According to some embodiments presented herein, in regeneration mode, and after the processing container has been heated, a cooling gas, formed from a portion of a second or third gas, is used to cool the processing container and passes through it. This operating mode is used to pre-condition the processing container for subsequent processing modes. In other embodiments, a dedicated cooling mode may be omitted, and cooling may be achieved in the first stage of a subsequent processing mode.

[0014] According to certain embodiments as presented herein, the portion of the second or third gas that forms the cooling gas accounts for 5% to 60% of the total volume of the second or third gas.

[0015] According to some embodiments presented herein, the cooling gas stream is passed through the processing container in a first direction, which can significantly reduce the cooling time. However, the passing of the cooling gas through the processing container can also be performed in a second direction.

[0016] According to certain embodiments presented herein, a first adsorption layer is used to adsorb and remove at least a portion of the water contained in a second gas upstream of the catalyst layer, and a second adsorption layer is used to adsorb and remove at least a portion of the water formed from oxygen in the catalyst layer. This enables the catalyst layer to be operated under nearly dry conditions, under which catalyst activity is enhanced.

[0017] According to certain embodiments presented herein, the regenerated gas, or a portion thereof, undergoes condensation to remove water, as has been done with the first gas, or a portion thereof, or undergoes separate condensation to remove water, and is then returned to the second gas, or a portion thereof, for adsorption to remove water and catalytic removal of oxygen. In other words, the water desorbed in regeneration mode can be largely removed before the regenerated gas re-enters the treatment unit.

[0018] According to certain embodiments presented herein, the condensation removal of water by the first gas or a portion thereof and / or the separate condensation removal of water by the regenerated gas or a portion thereof includes a cooling step and phase separation.

[0019] According to certain embodiments presented herein, the electrolytic conversion of water is carried out by low-temperature electrolysis or high-temperature electrolysis, or includes both low-temperature and high-temperature electrolysis. The embodiments presented herein can be used with all typical electrolysis processes known in the field of water electrolysis.

[0020] An apparatus for generating hydrogen, as proposed herein, includes: an electrolysis unit configured to provide a first gas containing hydrogen, oxygen, and water, including the electrolytic conversion of water; a condensation arrangement configured to provide a second gas containing hydrogen, oxygen, and water, including the condensation removal of water from the first gas or a portion thereof; and an adsorption and catalytic treatment arrangement including treatment containers configured to provide a third gas containing hydrogen, including the adsorption removal of water and the catalytic removal of oxygen from the second gas or a portion thereof.

[0021] In the device proposed herein, each processing container includes a first adsorption layer, a catalytic layer, and a second adsorption layer in a first direction from a first opening to a second opening. Each processing container is configured to operate alternately in a processing mode and a regeneration mode. In the processing mode, a second gas or a portion thereof is passed through the processing container in the first direction. In the processing mode, the first and second adsorption layers are used for the adsorption and removal of water, and the catalytic layer is used for the catalytic removal of oxygen. In the regeneration mode, the processing container is heated using a heated gas formed from a portion of the second or third gas, heated, and passing through the processing container.

[0022] For further details and advantages of this device, refer above to the explanation of the methods and implementations thereof presented herein. In particular, in the embodiments presented herein, such device may include components suitable for performing the methods according to any of the embodiments discussed herein. Attached Figure Description

[0023] The embodiments disclosed herein will now be described by way of example only, with reference to the accompanying drawings, in which...

[0024] Figure 1 Methods that do not constitute part of this invention are illustrated;

[0025] Figure 2 The layer layout according to the implementation plan is illustrated;

[0026] Figure 3A and Figure 3B The experimental results are illustrated; and

[0027] Figures 4 to 9 An example of the implementation scheme proposed in this article is provided. Implementation Plan

[0028] In the accompanying drawings, elements with the same, substantially the same, functionally equivalent, or technically compatible functions and / or purposes may be identified using the same reference numerals, and for the sake of brevity, redundant explanations may be omitted. The explanations herein relating to apparatus, equipment, arrangements, systems, etc., according to certain embodiments disclosed herein, also apply to methods, processes, procedures, etc., according to the corresponding embodiments.

[0029] The various embodiments described herein are provided only to aid in understanding and teaching the claimed features. These embodiments are provided as representative examples only and are not exhaustive and / or exclusive. It should be understood that the advantages, embodiments, examples, functions, features, structures and / or other aspects described herein should not be considered as limitations on the scope of the invention as defined by the claims or on the equivalents of the claims, and other embodiments may be utilized and modifications may be made without departing from the scope of the claimed invention.

[0030] The various embodiments disclosed herein may suitably include, consist of, or substantially consist of suitable combinations of the disclosed elements, components, features, parts, steps, components, etc., rather than those specifically described herein. Furthermore, this disclosure may include other inventions not currently claimed but which may be claimed in the future, particularly when covered by the scope of the independent claims.

[0031] For detailed information about the water electrolysis process involved in this disclosure, please refer to professional literature such as 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".

[0032] In traditional water electrolysis, an alkaline aqueous solution (typically an alkaline aqueous solution of potassium hydroxide) is used as the electrolyte (AEL, alkaline electrolysis). Alkaline electrolysis can be performed using a monopole or bipole electrode arrangement and at atmospheric pressure, or on an industrial scale at significantly higher pressures. In particular, higher pressures can be used to avoid subsequent compression.

[0033] Recent developments in water electrolysis include the use of proton-conducting ion-exchange membranes (SPE, solid polymer electrolysis; PEM, proton exchange membrane), in which water to be electrolyzed is supplied on the anode side. Electrolysis techniques using anion-exchange membranes (AEM) have also been employed.

[0034] The electrolysis processes mentioned so far are cryogenic processes, in which the water to be electrolyzed exists in a liquid phase. Alternatively, so-called vapor electrolysis can be used, which can also be performed using alkaline electrolytes and suitable membranes (e.g., polysulfone membranes) and using solid oxide electrolyzers (SOECs). The latter specifically includes oxides of doped zirconium dioxide or other rare earth elements.

[0035] As used herein, the term electrolysis is intended to encompass all of these processes. In particular, low-temperature electrolysis (PEM, AEL, AEM) is suitable for flexible operations supporting the transition to renewable energy. All processes can be used in the embodiments disclosed herein.

[0036] exist Figure 1 The diagram illustrates, but is not part of the present invention, an apparatus and method for producing hydrogen based on water electrolysis. For general purposes, the electrolysis unit is indicated by box 10.

[0037] A cathode feed stream containing hydrogen and a certain proportion of water and oxygen is taken out from electrolysis unit 10; this cathode feed stream is referred to herein as "first gas" 1. In the illustrated embodiment, first gas 1 is injected into a first separation container D1, in which the liquid phase and gas phase are separated from each other. The liquid feed stream 2 taken from the first separation container D1 expands into a second separation container D0, in which the gas still dissolved in the liquid phase from the first separation container D1 is removed by degassing. The liquid phase in the second separation container D0 is taken out as liquid feed stream 3 and can be returned to a location upstream of electrolysis unit 10, not shown in detail for simplicity. The gas phase formed in the second separation container D0 can be taken out as gaseous feed stream 4 and used for different purposes as needed.

[0038] The gaseous phase formed in the first separation container D1 is taken out as gaseous stream 5, heated in the electric heating unit E1, and passed through the catalytic unit R1, where oxygen reacts to form hydrogen and water, thereby forming an oxygen-deficient gaseous hydrogen stream 6 containing a certain amount of water. Stream 6 is combined with stream 12, which can be explained below, to produce a combined stream 7. To remove water, stream 7 is cooled with cooling water in the heat exchanger E2 and then supplied to the third separation container D2, where the liquid and gaseous phases are separated from each other. Liquid stream 8 taken out from the third separation container D2 can be used, as explained above. The gaseous phase formed in the third separation container D2 can be taken out as gaseous stream 9 from the third separation container D2.

[0039] exist Figure 1 In the illustrated method, an adsorption drying unit 110' comprising adsorption containers A' and B' is used, which in... Figure 1 The diagram illustrates an operating mode in which gaseous stream 9 is passed through container B' to form dry stream 10, while container A' is regenerated using regenerated gas stream 11. In the example shown, regenerated gas stream 11 is formed using a portion of the dry stream 10, which is compressed using blower B1 and then heated or cooled in temperature control unit E3. After passing through container A', the water-carrying regenerated gas stream 12, as mentioned above, can be returned. The remaining portion of dry stream 10 can be provided as a hydrogen product (not separately mentioned) or further processed to provide a hydrogen product (not separately mentioned). In subsequent operating modes, containers A' and B' can be switched such that stream 9 is supplied to container A' while regenerated gas stream 11 is used to regenerate container B'. Blower B1 can be located at the location shown, but it can also be located downstream of container A' (and B' in the aforementioned subsequent operating mode).

[0040] In other words, Figure 1 In the illustrated method, a "DeOxo" unit in the form of a catalytic unit R1 is used to remove oxygen, and drying is performed using an adsorption drying unit 110' arranged downstream of the DeOxo unit. For efficient operation of the DeOxo unit (i.e., catalytic unit R1), current prior art requires at least a preheater (such as...) Figure 1 The heater E1 shown is used to prevent water condensation and / or requires high temperatures and therefore energy. Furthermore, due to the still relatively high water content, a high amount of gaseous feedstock 5 for deoxygenation is required to enter the catalytic unit R1 to overcome the catalytic inhibition caused by water pressure. A blower B1 is also needed to guide the regeneration gas feedstock 11 back to the feedstock 7 via the gas feedstock 12, thereby overcoming any pressure drop caused by the components shown.

[0041] Typical operating conditions for catalytic unit R1 include a feed temperature at least 20 K above the dew point and 10,000 h at 20 to 30 bar. -1 Up to 50,000h -1 The gas hourly space velocity (GHSV) is shown. Table 1 below lists typical parameters for feed stream 5 (µs / ds) upstream and downstream of heater E1, as well as feed streams 9 and 10. Oxygen and water content are given in vppm (parts per million by volume).

[0042] Table 1

[0043] exist Figure 1 Several problems may arise in the arrangement shown.

[0044] The first problem is that water from feed stream 1 must be separated at relatively high pressure in the first separation vessel D1, and then feed stream 5 must be heated in heater E1 for the deOxo reactor or catalytic unit R1, and then cooled again in cooler E2. The reason is that, for efficient dehydration in the adsorption drying unit 110, water must be condensed and separated in the third separation vessel D2. This is energy-intensive, and at least some energy is lost.

[0045] The second problem is that the water separated in the third separation vessel D2 (i.e., feed stream 8) may be contaminated by fine catalyst particles composed of alumina or other oxides (such as silica) from the catalytic unit R1 or from the currently regenerating vessels A' or B'. These particles may damage the membranes used in the electrolysis unit 10. Therefore, this water must be purified for use as electrolysis makeup water or rejected altogether. This represents additional effort or a loss of resources.

[0046] The third issue is the need for multiple containers (reactors, separators, adsorption beds), which translates to high capital costs and space requirements. This is particularly true for containerized solutions, which necessitate more compact systems.

[0047] The fourth problem is that the feed stream 5 to heater E1 is water-saturated, and if the electrolysis unit 10 operates using a proton exchange membrane, for example, this feed stream may contain 100 vppm to 1000 vppm of oxygen. Due to the catalytic inhibition of catalytic oxidation by water vapor, the high water content may necessitate an additional catalyst for the catalytic reactor R1.

[0048] The fifth issue is that the two-step process (deOxo, followed by adsorption drying) results in pressure losses. Therefore, as mentioned, a blower B1 as shown in the figure may be required, along with a higher adsorber capacity due to the increased flow rate, leading to additional capital and operating costs, space requirements, and increased system complexity.

[0049] To overcome these problems, the methods disclosed herein involve integrating oxygen removal and drying in separate layers within the same adsorption vessel, which are thus referred to as “processing vessels” A and B, and in the language used herein, they are part of a “(adsorption and catalytic) processing arrangement” 110. This approach saves capital costs and improves efficiency. The disclosed aspects relate to a regeneration system for the proposed combined unit.

[0050] exist Figure 2 In the schematic diagram 210, the layered arrangement in the processing containers A and B as proposed in the embodiment herein is illustrated. The flow direction of the material flow processed using this layered arrangement is indicated by arrow 201.

[0051] On the inlet side of the layer arrangement 210, a first adsorbent layer 211 is provided, which is configured to efficiently remove water. The first adsorbent layer 211 may comprise materials such as silica gel, activated alumina, molecular sieves, metal-organic frameworks, alumina-molecular sieve composites, or any combination of these adsorbents. The primary function of the first adsorbent layer 211 is to dry the gas before it enters the catalyst layer 212, thereby improving the efficiency of the catalyst. The catalyst layer 212 is positioned downstream of the first adsorbent layer 211. For oxygen conversion, a catalyst, such as alumina spheres impregnated with 0.1% to 0.3% by weight of a noble metal (such as palladium, platinum, or a mixture thereof), may be used in the catalyst layer 212. Non-metallic catalysts (e.g., nickel-based catalysts) may also be used, and these non-metallic catalysts may even be provided in the form of hydrated catalysts.

[0052] Since water is generated during the catalytic conversion in catalyst layer 212, a second adsorbent layer 213 is required to remove the water generated downstream of catalyst layer 212. Examples include silica gel, activated alumina, molecular sieves, metal-organic frameworks, alumina-molecular sieve composites, or any combination of these adsorbents, which may be the same as or different from those used in the first adsorbent layer 211 discussed above.

[0053] It can be demonstrated that in this arrangement 210, adsorbent layers 211 and 213 remove water from the feed and deOxo reaction of arrangement 210, and furthermore, the catalyst used in catalyst layer 212 works efficiently even at the lower temperatures required for a highly efficient dehydration bed. Oxygen concentrations below the detection limit (i.e., below 0.1 ppm) and water concentrations below 0.1 ppm, 0.5 ppm, 1 ppm, 2 ppm, or 5 ppm were achieved for 6 hours.

[0054] Figure 3A and Figure 3B Examples of using Figure 2The results of experiments conducted on the layer arrangement 210 shown are as follows: this layer arrangement has a 100 ml dehydration bed or catalyst layer 211, a 10 ml catalyst layer 212, and a 22 ml dehydration bed or catalyst layer 213, wherein the usage time in hours is illustrated on the horizontal axis, and the oxygen content in vppm is illustrated on the vertical axis. Figure 3A ) and water content ( Figure 3B ).exist Figure 3A In the feed, the calculated (solid line) and measured (at various points) oxygen content is indicated by 311, and the measured oxygen content in the effluent is indicated by 312. Figure 3B In this process, the water content in the feed is indicated using 321, and the water content measured in the effluent is indicated using 322. Figure 3B The standard is illustrated using line 323.

[0055] Under the expected operating conditions (30 bar absolute pressure, 40°C), the combined process achieved the specified hydrogen purity (within a 6-hour time window). Increasing the oxygen feed concentration to 1000 vppm, increasing the total feed to 1200 l / h, or even reducing the pressure to 2.5 bar (absolute) did not produce a detectable amount of oxygen in the illustrated setup. This highlights the high activity of this catalytic zone within the dehydration bed.

[0056] implement Figure 3A and Figure 3B The experiments shown continued until the second adsorbent layer 213 downstream of the catalyst layer 212 was consumed, and the first adsorbent layer 211 upstream of the catalyst layer began to be consumed. It was demonstrated that even at moisture contents of 400 ppm to 1000 ppm, oxygen levels remained below the detection limit of 0.1 ppm. The expected moisture content from the catalyst layer was 200 v ppm. Therefore, surprisingly low moisture content at the inlet is not required, and maximum requirements, such as the distance to the dew point of water, can be limited to a maximum of 20 K. This further optimizes the size of the dehydration bed 211.

[0057] Table 2 below indicates the characteristic parameters used or obtained when the catalyst layer 212 is operated under incompletely dry conditions for two scenarios. "Feed gas" refers to the gas supplied to the layer arrangement.

[0058] Table 2

[0059] For the described function of the catalyst in catalyst bed 212, the first adsorbent layer 211 is designed to protect the catalyst from water condensation (at least above the dew point of 0K to 20K). The ratio of product gas flow rate in standard or normal cubic meters per hour to catalyst volume in cubic meters is at least 74,000 h⁻¹. -1And at most 150,000h -1 For technical applications, the layer height is preferably not less than 5 cm to avoid gas bypassing through the layer due to inaccurate filling. The second adsorbent layer 213 downstream of the catalyst layer 212 is designed to adsorb water formed during catalytic oxidation. The water removal capacity should allow the adsorption period to be equal to the adsorption period of the adsorbent layer 211, i.e., more than 3 to 12 hours.

[0060] Since adsorption is a discontinuous process, at least two absorber containers A' and B' (such as...) are required. Figure 1 (As shown) and corresponding two processing containers A and B, to continuously produce material streams, such as a continuous gas stream 10. For this and all the following arrangements, in aspects of the embodiments disclosed herein, the flow direction is not fixed.

[0061] As is generally known, such as Figure 1 The regeneration adsorption containers A' and B' shown include passing heated gas through them to desorb components from the adsorbent material or adsorbent. A cooling mode is then performed to prepare the adsorption containers A' and B' for subsequent adsorption modes. More generally, for each adsorption container A' and B', an adsorption mode performed during the adsorption period is followed by a regeneration mode performed during the regeneration period, which includes a desorption or heating (sub)period performed during the desorption or heating (sub)period and a cooling (sub)period performed during the cooling (sub)period. In the language used herein, the desorption or heating sub-period and the cooling sub-period can be considered as sub-periods of the regeneration mode. However, from a different perspective, the cooling mode can be considered not strictly part of the regeneration mode, but a separate operating mode such that the cooling period does not constitute part of the regeneration mode. The invention is not limited by the use of language.

[0062] In the following text, reference will be made to "heating gas" used in desorption or heating modes, and "cooling gas" used in cooling modes. Furthermore, the term "processing mode" will be used in the following text instead of "adsorption mode," as this also includes catalytic conversion.

[0063] The embodiments disclosed herein are characterized by the cooling gas passing through adsorption containers A' and B' in the same direction as the adsorption flow in the subsequent adsorption mode. Although a three-way valve is shown below for simplicity, the embodiments disclosed herein are not limited to the use of a particular type of valve. Different manifolds composed of different valves can be used, as long as the desired flow direction and sequence can be achieved. Even a blower can be used to generate the required pressure differential.

[0064] The combination of catalytic conversion and adsorption drying proposed in this paper has achieved capital cost savings that surpass any existing purification technology, while also enabling a compact process design.

[0065] Figure 4 Methods and apparatus for generating hydrogen according to embodiments as presented herein are illustrated and are generally indicated by 100.

[0066] like Figure 4 As shown, a cathode feed stream 1 from the cathode side of the electrolysis unit 10 is taken out, and this cathode feed stream can correspond to... Figure 1 The cathode feed stream shown, and referred to herein as "first gas" 1, is cooled in cooler E10 upstream of the first separation vessel D1. As described above, the liquid phase in the first separation vessel D1 can be sent as liquid feed stream 2 to the second separation vessel D0, such as... Figure 1 As illustrated, but for the sake of brevity, in Figure 4 Not shown in the diagram. The gas phase from the first separation container D1 is taken out as a gaseous stream, referred to herein as "second gas" 5, a portion of which (still referred to as 5) is transferred to the processing container B operating in adsorption mode.

[0067] In processing containers A and B, such as combining... Figure 2 As discussed, the catalyst layer 212 is arranged between the first adsorption layer 211 and the second adsorption layer 213. Therefore, a corresponding adsorption mode can be provided in the adsorption container B. Figure 1 The feed stream 10 is an oxygen-deficient dry feed stream, referred to herein as "third gas" 10. Valves V2 and V3 are used to switch between containers A and B for adsorption.

[0068] In heating or desorption mode, a portion of the second gas 5 (referred to herein as heating gas 5a) is heated in heater E4, and then, as controlled by valves V4A and V5A in the case of container A (or by valves V4B and V5B in the case of container B), this portion of the flow passes through adsorption container A in the opposite direction to that of the second gas 5 in adsorption mode. Figure 4 As shown. Then, the heated gas 5a is cooled by the carrier water in heat exchanger E2, and the water from the heat exchanger is separated in the third separation vessel D2. The remaining gas phase is returned as stream 5c to be recombined with stream 5, while stream 8 can be combined with stream 2. Figure 4 In the illustrated implementation scheme, the desorption gas can be in a ratio according to Figure 1 The third separation vessel D2 and heat exchanger E2 provided are for cooling in smaller equipment. Although Figure 4An example is shown where the heated gas 5a passes through the container in one direction, but the opposite direction can also be used in other alternatives.

[0069] In cooling mode, a portion of the second gas 5 (referred to herein as cooling gas 5b) is extracted upstream of heater E4 and then passed through adsorption container A in the same direction as the flow 5 in adsorption mode, as controlled by valves V7 and V6. Cooling gas 5b is then passed through heat exchanger E2 and third separation container D2, and as in heating or desorption mode, flow 5c recombines with flow 5. Water can be separated in the third separation container D2.

[0070] The regeneration gases used for cooling or heating (i.e., heating gas 5a and cooling gas 5b) can be drawn from the feed stream 5 downstream of the first separation vessel D1 and upstream of the combined processing arrangement 110 (e.g., Figure 4 (As shown), but it can also be taken from the purified hydrogen 10 downstream of the processing arrangement 110 (as shown). Figure 4 (Not shown in the image). To ensure that the closed-loop regeneration scheme does not lose any product, a blower and / or a pressure reducing valve can be used.

[0071] As the heating gas 5a, a second gas 5 in an amount of 5% to 60% can be used. The regenerated gas 5a can be heated in heater E4 to a desorption temperature of 70°C to 300°C. Similarly, a second gas 5 in an amount of 5% to 60% can also be used as the cooling gas 5b. Because the cooling gas stream 5b contains moisture when it is formed as part of the gas stream 5, the gas stream must flow in the adsorption direction. Any condensable moisture can be removed as shown in the figure before recombinating the gas stream 5c with the fraction downstream of valve V1.

[0072] During the adsorption mode of container B, in Figure 4 In the example shown, moisture in gas stream 5 is removed in the first adsorption layer 211. Furthermore, the contained oxygen is catalytically converted into water in the catalytic layer 212 and thus removed from stream 5. Water generated during the conversion is removed in the second adsorption layer 213. The target for the final hydrogen product or stream 10 is an oxygen content of less than 5 ppmv and a water content of less than 50 ppmv, particularly less than 5 ppmv.

[0073] During the regeneration step, trapped moisture in containers A and B is released, and oxygen contained in the regeneration gas stream 5a can be catalytically converted into water, resulting in additional efficiency in overall oxygen removal. The catalyst can be regenerated simultaneously during regeneration even when it is already saturated with moisture.

[0074] Figure 5Methods and apparatus for generating hydrogen according to embodiments as presented herein are illustrated and are generally indicated by 200.

[0075] and Figure 4 In the opposite embodiment shown, a portion of the dry gas stream 10a is used for regeneration. In the second arrangement, the regeneration gas is the product gas. 5% to 60% of the stream 10 can be directed via blower B1 to heater E4 for regeneration, heating the regeneration gas to a desorption temperature of 70°C to 300°C. Essentially as already combined... Figure 4 The hot regenerated gas stream discussed is fed into adsorber A in regeneration mode against the adsorption direction. Then, as... Figure 4 As shown in the feed stream 5a, the regenerated gas feed stream 10a is cooled by heat exchanger E2, and water is separated in third separation container D2 before the regenerated gas feed stream 10a is recombined with the feed stream 5 downstream of the first separation container D1 and upstream of the adsorption unit 110. The mixture is then sent to adsorption container B in adsorption mode. The location of blower B1 does not necessarily affect the process. Blower B1 can be placed upstream of heater E4, or even downstream of heater E4 or downstream of separation container D2. Importantly, blower B1 compensates for pressure loss in order to remix with the feed.

[0076] After regeneration, a cooling bed or layer 211, 212, 213 is also required in this arrangement, after which it can re-enter the adsorption step. For this purpose, heater E4 is bypassed or shut off (not shown), and cooling gas is sent to container B in regeneration mode in the same manner as desorbed gas 10a, directed to cooler E2 and separator D2, and recombined with feed stream 5.

[0077] In this embodiment and some of the embodiments below, a blower is not required, and the pressure drop “retained” in deOxo during feed regeneration can be used in a pressure reducing valve. An additional advantage is that since the load on the adsorber remains the same compared to product regeneration with an increased amount of regeneration gas, it is not necessary to increase the container capacity.

[0078] The problem addressed in this embodiment and some other embodiments is that, since DeOxo layers are included in containers A and B, a nearly dry feed with at most 100 ppmv of water is not required at the inlet. Therefore, it is not necessary to almost completely remove water in the upstream adsorbent unit.

[0079] Figure 6 Methods and apparatus for generating hydrogen according to embodiments as presented herein are illustrated and are generally designated as 300.

[0080] In contrast to the previously discussed implementation, a cooling mode is not performed. The heating mode is performed for almost the same duration as the adsorption step. This means that the cooling mode typically used before the heated adsorber container enters the adsorption process is omitted. Therefore, the heat stored after the heating step is expelled from the bed during the adsorption step. Since a thermal peak is generated at the beginning of the adsorption step, a cooler E5 is used for the treated gas 10 (i.e., the hydrogen product).

[0081] The treated gas leaving the adsorber (adsorber B in this example) currently in the adsorption step is cooled using E5. During the adsorption step, the adsorber itself is cooled after the heating step. The fact that the cooling step can be omitted results in a reduction in peak power values, and heater E4 can operate more smoothly.

[0082] Figure 7 Methods and apparatus for generating hydrogen according to embodiments as presented herein are illustrated and are generally designated as 400.

[0083] exist Figure 7 In the illustrated embodiment, the cathode feed stream 1 from electrolysis unit 10 is cooled in heat exchanger E10, and water is separated in the first separation container D1. Stream 5 is directed to the adsorber container B in adsorption mode. Regeneration gas 5a for heating the adsorber container A in regeneration mode and cooling gas 5b can also be sent to heat exchanger E10 and separation container D1, thus saving the need for separate coolers and separators (as previously shown, D2, E2) for these gas streams. The regeneration gas and cooling gas can be taken from either stream 5 or stream 10. For the purposes explained above, a blower B1 can be used.

[0084] Figure 8 Examples of methods and apparatus for generating hydrogen according to embodiments as presented herein are illustrated and are generally designated as 500. Figure 9 Methods and apparatus for producing hydrogen according to embodiments as presented herein are illustrated and are generally designated as 600. These embodiments correspond to Figure 7 The implementation scheme shown is combined with the already combined Figure 5 and Figure 6 The combination of features discussed.

[0085] Table 3 indicates typical parameters for feed flow 1 upstream of heat exchanger 10, feed flow 5 upstream of adsorption vessel in adsorption mode, and feed flow 10. Product flow rate (in Nm³) 3 (in units of / h) and m 3 The ratio of catalyst layer 212 is typically around 70000 Nm. 3 h -1 m -3 Up to 150,000 Nm 3 h-1 m -3 Within the range. The temperature difference between the upstream temperature of the catalyst layer 212 and the dew point is in the range of 0K to 20K above the dew point. As mentioned, the regeneration or cooling gases 5a, 5b, 10a, and 10b can be provided in a proportion of 5% to 60% compared to the product gas 10 or the gas stream 5.

[0086] Table 3

Claims

1. A method (100-600) for generating hydrogen, the method comprising providing a first gas (1) containing hydrogen, oxygen and water, the provision of the first gas (1) comprising the electrolytic conversion of water; providing a second gas (5) containing hydrogen, oxygen and water, the provision of the second gas (5) comprising condensing and removing water from the first gas (1) or a portion thereof; and providing a third gas (10) containing hydrogen, the provision of the third gas (10) comprising using an adsorption and catalytic treatment arrangement (110) including treatment containers (A, B) to adsorb and remove water and catalytically remove oxygen from the second gas (5) or a portion thereof, wherein each treatment container (A, B) includes a first adsorption layer (211), a catalytic layer (212) and a second adsorption layer (213) in a first direction from a first opening to a second opening, wherein each treatment container (A, B) operates alternately in a treatment mode and a regeneration mode, wherein, In the processing mode, the second gas (5) or a portion thereof is passed through the processing container (A, B) in the first direction, wherein, in the processing mode, the first adsorption layer (211) and the second adsorption layer (213) are used for the adsorption removal of water, and the catalytic layer (212) is used for the catalytic removal of oxygen, wherein, in the regeneration mode, the processing container (A, B) is heated using a heating gas (5a) formed from a portion of the second gas (5), heated, and passing through the processing container (A, B).

2. The method (100-600) according to claim 1, wherein the first adsorption layer (211) has a volume of 50% to 80% of the total volume of the first adsorption layer, the catalyst layer and the second adsorption layer, the catalyst layer (212) has a volume of 5% to 10% of the total volume, and the second adsorption layer (213) has a volume of 10% to 40% of the total volume.

3. The method (100-600) according to claim 1 or 2, wherein the heating gas (5a) is passed through the processing container (A, B) in the first direction or in a second direction opposite to the first direction.

4. The method (100-600) according to any one of the preceding claims, wherein the first gas (1) contains hydrogen with a first hydrogen content, water with a first water content, and oxygen with a first oxygen content, the second gas (5) contains hydrogen with a second hydrogen content, water with a second water content, and oxygen with a second oxygen content, and the third gas (10) contains hydrogen with a third hydrogen content, wherein the first water content is a water content higher than the saturation content, wherein the second water content is a water content corresponding to the saturation content, and wherein the third water content is 0 parts per million to 50 parts per million or 0 parts per million to 5 parts per million based on volume, and / or wherein the first oxygen content is 50 parts per million to 1000 parts per million based on volume, wherein the second oxygen content is 50 parts per million to 1000 parts per million based on volume, and wherein the third oxygen content is 0 parts per million to 5 parts per million based on volume.

5. The method according to any one of the preceding claims, wherein the first gas (1) is provided at an absolute pressure of 10 bar to 40 bar and a temperature of 50°C to 70°C, wherein the second gas (5) is provided at an absolute pressure of 10 bar to 40 bar and a temperature of 10°C to 50°C, and wherein the third gas (10) is provided at an absolute pressure of 10 bar to 40 bar and a temperature of 10°C to 70°C.

6. The method according to any one of the preceding claims, wherein the portion of the second gas (5) forming the heated gas (5a) accounts for 5% to 60% of the second gas (5) by volume.

7. The method according to any one of the preceding claims, wherein in the regeneration mode, and after the processing containers (A, B) are heated, cooling gases (5a, 10a) are used to cool the processing containers (A, B), the cooling gases being formed from a portion of the second gas (5) or the third gas (10) and passing through the processing containers (A, B).

8. The method according to claim 7, wherein the portion of the second gas (5) or the third gas (10) forming the cooling gas (5a, 10a) is a ratio of 5% to 60% by volume of the second gas (5) or the third gas (10).

9. The method according to claim 7 or 8, wherein the cooling gas stream (5b, 10b) passes through the processing container (A, B) in the first direction or in a second direction opposite to the first direction.

10. The method according to any one of the preceding claims, wherein the first adsorption layer (211) is used to adsorb and remove at least a portion of the water contained in the second gas (5) upstream of the catalyst layer (212), and the second adsorption layer (213) is used to adsorb and remove at least a portion of the water formed by oxygen in the catalyst layer (212).

11. The method according to any one of the preceding claims, wherein the regenerated gas (5a, 10a) or a portion thereof is subjected to the condensation removal of water as the first gas (1) or a portion thereof has been subjected to, or is subjected to separate condensation removal of water, and is then returned to the adsorption removal of water and the catalytic removal of oxygen as the second gas (5) or a portion thereof has been subjected to.

12. The method according to claim 11, wherein the condensation removal of water experienced by the first gas (1) or a portion thereof and / or the separate condensation removal of water experienced by the regenerated gas (5a, 10a) or a portion thereof comprises a cooling step and phase separation.

13. The method according to any one of the preceding claims, wherein the electrolytic conversion of water is carried out by low-temperature electrolysis or high-temperature electrolysis, or includes the low-temperature electrolysis or the high-temperature electrolysis.

14. An apparatus for generating hydrogen, the apparatus comprising an electrolysis unit (10) configured to provide a first gas (1) containing hydrogen, oxygen, and water, including the electrolytic conversion of water; a condensation arrangement (E10, D1) configured to provide a second gas (5) containing hydrogen, oxygen, and water, including the condensation removal of water from the first gas (1) or a portion thereof; and an adsorption and catalytic treatment arrangement (110) comprising treatment containers (A, B) configured to provide a third gas (10) containing hydrogen, including the adsorption removal of water and the catalytic removal of oxygen from the second gas (5) or a portion thereof, wherein each of the treatment containers (A, B) comprises a first adsorption layer (211), a catalytic layer (212), and a second adsorption layer (213) in a first direction from a first opening to a second opening, wherein each of the treatment containers (A, B) is configured to operate alternately in a treatment mode and a regeneration mode, wherein, In the processing mode, the second gas (5) or a portion thereof is passed through the processing container (A, B) in the first direction, wherein, in the processing mode, the first adsorption layer (211) and the second adsorption layer (213) are used for the adsorption removal of water, and the catalytic layer (212) is used for the catalytic removal of oxygen, wherein, in the regeneration mode, the processing container (A, B) is heated using a heating gas (5a) formed from a portion of the second gas (5), heated, and passing through the processing container (A, B).

Images