Electrolysis plant with mutualization and modularization for hydrogen production

Abstract

A hydrogen production facility is disclosed, comprising: a plurality of electrolysis systems to electrolyze water using lye; and a mutualized lye circulation system coupled with the plurality of electrolysis systems to circulate the lye among the plurality of electrolysis systems to facilitate electrolyzing the water, the lye circulation system comprising one or more pumps, wherein a number of the one or more pumps is less than a number of electrolysis systems of the plurality of electrolysis systems. A hydrogen production facility comprising first and second modular structures is also disclosed.

Description

ELECTROLYSIS PLANT WITH MUTUALIZATION AND MODULARIZATION FOR HYDROGEN PRODUCTIONTechnical Field

[0001] The present disclosure relates to facilities for production of Hydrogen by electrolysis.Background

[0002] Hydrogen can be an alternative energy source to hydrocarbons because it is an easily storable source of energy as compared to electricity, and oxidation of hydrogen releases a very high amount of energy. Hydrogen can be produced by one or more water electrolyzer system using electrolysis to separate water into dihydrogen and dioxygen. Produced hydrogen can be green hydrogen and can be used as a clean energy vector, transported easily, stored easily, and the like. Optimizing the electrolysis plants to enhance the productivity, the safety, and the like of the electrolysis plants can be challenging.Summary of the Disclosure

[0003] In one aspect, there is provided a hydrogen production facility, which may comprise any or all of the following features: a plurality of electrolysis systems to electrolyze water using lye; and a mutualized lye circulation system coupled with the plurality of electrolysis systems to circulate the lye among the plurality of electrolysis systems to facilitate electrolyzing the water, the lye circulation system comprising one or more pumps, wherein a number of the one or more pumps is less than a number of electrolysis systems of the plurality of electrolysis systems.

[0004] The lye circulation system may comprise a set of lye circulation lines sized to convey the lye between the plurality of electrolysis systems and a pump in a closed loop.

[0005] The lye circulation system may comprise a lye cleaning subsystem positionable along the lye circulation system to clean the lye. The lye cleaning subsystem may be arranged within the set of lye circulation lines to clean the lye while the lye is circulating within the lye circulation system.

[0006] The lye circulation system may comprise a set of lye circulation lines sized to convey the lye to the plurality of electrolysis systems. The lye circulation system may comprise one or more cleaning tanks couplable with the set of lye circulation lines. The one or more cleaning tanks may be sized to receive and clean the lye in situ in response to conveying the lye from the set of lye circulation lines to the one or more cleaning tanks.

[0007] The lye circulation system may comprise a lye circuit for circulating lye to and from the plurality of electrolysis systems. The lye circulation system may comprise a purification line comprising at least one lye purification system. The purification line may be in fluid communication with the lye circuit and may be configured to divert a portion of lye from the lye circuit to the at least one lye purification system and to re-introduce lye into the lye circulation system after passing through the at least one purification system.

[0008] The purification system may comprise a first separation unit configured to remove gases and / or solids from the lye in the purification line.

[0009] The first separation unit may comprise one or more of: a gravity separator or a settling tank.

[0010] The purification system may comprise a second separation unit configured to remove solids from the lye in the purification line. The second separation unit may be downstream of the first separation unit.

[0011] The second separation unit may comprise a purification unit and / or a membrane separator.

[0012] The second separation unit may comprise one or more of: a filter, resin, ferrite, apatite.

[0013] The purification line may comprise at least one heat exchanger.

[0014] The purification line may comprise at least one pressure reduction valve.

[0015] The purification line may comprise at least one pump.

[0016] The lye circuit may comprise one or more in-line filtration units configured to remove solids from the lye in the lye circuit.

[0017] The lye circulation system may be configured such that no more than 10 vol%, optionally no more than 5 vol%, optionally no more than 2 vol% of lye in the lye circulation system is diverted to the purification line during operation.

[0018] The hydrogen production facility may comprise a first structure having a first interior and a first roof. The hydrogen production facility may comprise a set of one or more power conversion units. The plurality of electrolysis systems may be positioned within the first structure. The set of one or more power conversion units may be positioned on the first structure and coupled with the plurality of electrolysis systems.

[0019] The hydrogen production facility may comprise a second structure having a second interior and a second roof. The second structure may be positioned offset from the first structure. The plurality of electrolysis systems may be positioned within the firststructure and the second structure. The set of power conversion units may be positioned on the first structure and the second structure and coupled with the plurality of electrolysis systems.

[0020] The plurality of electrolysis systems may comprise a first subset of electrolysis systems and a second subset of electrolysis systems. The first subset of electrolysis systems may be positioned in the first interior. The second subset of electrolysis systems may be positioned in the second interior.

[0021] The set of power conversion units may comprise a first subset of power conversion units and a second subset of power conversion units. The first subset of power conversion units may be positioned on the first roof and coupled with the first subset of electrolysis systems. The second subset of power conversion units may be positioned on the second roof and coupled with the second subset of electrolysis systems.

[0022] The first subset of power conversion units may comprise a first set of transformers having a first number of transformers. The second subset of power conversion units may comprise a second set of transformers having a second number of transformers. The first subset of electrolysis systems may comprise a third number of electrolysis systems. The second subset of electrolysis systems may comprise a fourth number of electrolysis systems.

[0023] The first number of transformers may be less than the third number of electrolysis systems.

[0024] The second number of transformers may be less than the fourth number of electrolysis systems.

[0025] The plurality of electrolysis systems may be comprised in a modular structure. The plurality of electrolysis systems may be installed in the modular structure, such that the modular structure comprising the set of power conversion units, can be provided to and installed in the hydrogen production facility.

[0026] The plurality of electrolysis systems may be comprised in a modular structure that further comprises one or more of: a set of power conversion units and a set of separators. The plurality of electrolysis systems, the at least one of the set of power conversion units, and the set of separators may be installed in one or more modules of the modular structure, such that the modular structure comprising at least one of the plurality of electrolysis systems, the set of power conversion units, and the set of separators, can be provided to and installed in the hydrogen production facility.

[0027] The plurality of electrolysis systems may be comprised in a modular structure that further comprises: a set of power conversion units and a set of separators. The plurality of electrolysis systems, the set of power conversion units, and the set of separators may be installed in one or more modules of the modular structure, such that the modular structure comprising the plurality of electrolysis systems, the set of power conversion units, and the set of separators, can be provided to and installed in the hydrogen production facility.

[0028] The hydrogen production facility may comprise a second modular structure that is different than the modular structure. The second modular structure may comprise one or more of: a second plurality of electrolysis systems that is different than the plurality of electrolysis systems; a second set of power conversion units that is different than the set of power conversion units; and a second set of separators that is different than theset of separators. The second plurality of electrolysis systems, the second set of power conversion units, and the second set of separators may be installed in one or more modules of the second modular structure, such that the modular structure comprising the second plurality of electrolysis systems, the second set of power conversion units, and the second set of separators, can be provided to and installed in the hydrogen production facility.

[0029] The modular structure may comprise a first housing that comprises a first set of walls. The plurality of electrolysis systems may have a first distance measured between a first end of each electrolysis system of the plurality of electrolysis systems and at least one wall of the first set of walls. The plurality of electrolysis systems may have a second distance measured between a second end of each electrolysis system of the plurality of electrolysis systems and a third end of an adjacent electrolysis system of the plurality of electrolysis systems.

[0030] The second modular structure may comprise a second housing that comprises a second set of walls. The second plurality of electrolysis systems may have a third distance measured between a first end of each electrolysis system of the second plurality of electrolysis systems and at least one wall of the second set of walls. The second plurality of electrolysis systems may have a fourth distance measured between a second end of each electrolysis system of the second plurality of electrolysis systems and a third end of an adjacent electrolysis system of the second plurality of electrolysis systems. The first distance may be the same as the third distance. The second distance may be the same as the fourth distance.

[0031] According to an aspect, there is provided a hydrogen production facility which may comprise any or all of the following features: at least one first modular structure comprising at least one of: a first set of electrolysis systems; a first set of power conversion units; and a first set of separators; wherein at least one of the first set of electrolysis systems, the first set of power conversion units, and the first set of separators is installable in the modular structure prior to the first modular structure being provided to and installed in the hydrogen production facility.

[0032] The hydrogen production facility may comprise a second modular structure that is different than the first modular structure. The second modular structure may comprise at least one of: a second set of electrolysis systems that is different than the first set of electrolysis systems; a second set of power conversion units that is different than the first set of power conversion units; and a second set of separators that is different than the first set of separators. At least one of the second set of electrolysis systems, the second set of power conversion units, and the second set of separators are installable in the second modular structure prior to the second modular structure being provided to and installed in the hydrogen production facility.

[0033] The hydrogen production facility may comprise the first modular structure comprising: the first set of electrolysis systems; the first set of power conversion units; and the first set of separators. The first set of electrolysis systems, the first set of power conversion units, and the first set of separators may be installable in the first modular structure prior to the first modular structure being provided to and installed in the hydrogen production facility. The hydrogen production facility may comprise the second modular structure that is different than the first modular structure. The second modular structuremay comprise: the second set of electrolysis systems that is different than the first set of electrolysis systems; the second set of power conversion units that is different than the first set of power conversion units; and the second set of separators that is different than the first set of separators. The second set of electrolysis systems, the second set of power conversion units, and the second set of separators may be installable in the second modular structure prior to the second modular structure being provided to and installed in the hydrogen production facility.

[0034] The first modular structure may comprise a first housing that comprises a first set of walls. The first set of electrolysis systems may have a first distance measured between a first end of each electrolysis system of the first set of electrolysis systems and at least one wall of the first set of walls. The first set of electrolysis systems may have a second distance measured between a second end of each electrolysis system of the first set of electrolysis systems and a third end of an adjacent electrolysis system of the first set of electrolysis systems.

[0035] The second modular structure may comprise a second housing that comprises a second set of walls. The second set of electrolysis systems may have a third distance measured between a first end of each electrolysis system of the second set of electrolysis systems and at least one wall of the second set of walls. The second set of electrolysis systems may have a fourth distance measured between a second end of each electrolysis system of the second set of electrolysis systems and a third end of an adjacent electrolysis system of the second set of electrolysis systems.

[0036] The first distance may be the same as the third distance. The second distance may be the same as the fourth distance.

[0037] The first modular structure and the second modular structure may be installable in the hydrogen production facility to form a first structure and a second structure. The first structure may have a first interior and a first roof. The second structure may have a second interior and a second roof. The first structure and the second structure may be positionable offset from one another.

[0038] According to an aspect, there is provided a hydrogen production facility which may comprise any or all of the following features: a plurality of electrolysis systems to electrolyze water using lye; and at least one lye circulation system coupled with the plurality of electrolysis systems to circulate the lye among the plurality of electrolysis systems to facilitate electrolyzing the water, wherein the at least one lye circulation system comprises: a lye circuit for circulating lye to and from the plurality of electrolysis systems; and a purification line comprising a lye purification system, wherein the purification line is in fluid communication with the lye circuit and is configured to divert a portion of lye from the lye circuit to the purification system and to re-introduce lye into the at least one lye circulation system after passing through the purification system.

[0039] The purification system may comprise a first separation unit configured to remove gases and / or solids from the lye in the purification line.

[0040] The first separation unit may comprise one or more of: a gravity separator or a settling tank.

[0041] The purification system may comprise a second separation unit configured to remove solids from the lye in the purification line. The second separation unit may be downstream of the first separation unit.

[0042] The second separation unit may comprise a purification unit and / or a membrane separator.

[0043] The second separation unit may comprise one or more of: a filter, resin, ferrite, apatite.

[0044] The purification line may comprise at least one heat exchanger.

[0045] The purification line may comprise at least one pressure reduction valve.

[0046] The purification line comprises at least one pump.

[0047] The lye circuit may comprise one or more in-line filtration units configured to remove solids from the lye in the lye circuit.

[0048] The lye circulation system may be configured such that no more than 10 vol%, optionally no more than 5 vol%, optionally no more than 2 vol% of lye in the lye circulation system is diverted to the purification line during operation.

[0049] It will be appreciated that any or all of the embodiments described herein may be applied to the method.

[0050] According to an aspect, there is provided a method comprising any or all of the following steps: installing one or more of a first set of electrolysis systems, a first set of power conversion units, and a first set of separators in a first modular structure prior to the first modular structure being provided to a site of a hydrogen production facility; providing the first modular structure to the site of hydrogen production facility; and installing the first modular structure in the hydrogen production facility.

[0051] According to an aspect, there is provided a method comprising any or all of the following steps: providing at least one modular structure as described herein;delivering the modular structure to a site of a hydrogen production facility; and installing the hydrogen production facility using the at least one modular structure.

[0052] According to an aspect, there is provided a hydrogen production facility comprising: a plurality of electrolysis systems to electrolyze water using lye; and a lye circulation system coupled with the plurality of electrolysis systems to circulate the lye among the plurality of electrolysis systems to facilitate electrolyzing the water, the lye circulation system comprising: one or more pumps, wherein a number of the one or more pumps is less than a number of electrolysis systems of the plurality of electrolysis systems; and a lye cleaning subsystem positioned or positionable along the lye circulation system to clean the lye.

[0053] The lye circulation system may comprise a set of lye circulation lines sized to convey the lye to the plurality of electrolysis systems. The lye cleaning subsystem may be arranged within the set of lye circulation lines to clean the lye while the lye is circulating within the lye circulation system.

[0054] The lye circulation system may comprise a set of lye circulation lines sized to convey the lye to the plurality of electrolysis systems. The lye circulation system may comprise one or more cleaning tanks coupled or couplable with the set of lye circulation lines. The one or more cleaning tanks may be sized to receive and clean the lye in situ in response to conveying the lye from the set of lye circulation lines to the one or more cleaning tanks.

[0055] The hydrogen production facility may further comprise: a first structure may have a first interior and a first roof; a second structure having a second interior and a second roof, wherein the second structure is positioned or positionable offset from thefirst structure; and a set of power conversion units. The plurality of electrolysis systems may be positioned or positionable within the first structure and the second structure. The set of power conversion units may be positioned or positionable on the first building and the second building and may be coupled with the plurality of electrolysis systems.

[0056] The plurality of electrolysis systems may comprise a first subset of electrolysis systems and a second subset of electrolysis systems. The first subset of electrolysis systems may be positioned or positionable in the first interior. The second subset of electrolysis systems may be positioned or positionable in the second interior. The set of power conversion units may comprise a first subset of power conversion units and a second subset of power conversion units. The first subset of power conversion units may be positioned or positionable on the first roof and coupled or couplable with the first subset of electrolysis systems. The second subset of power conversion units may be positioned or positionable on the second roof and coupled or couplable with the second subset of electrolysis systems.

[0057] The first subset of power conversion units may comprise a first set of transformers having a first number of transformers. The second subset of power conversion units may comprise a second set of transformers having a second number of transformers. The first subset of electrolysis systems may comprise a third number of electrolysis systems. The second subset of electrolysis systems may comprise a fourth number of electrolysis systems. The first number of transformers may be less than the third number of electrolysis systems.

[0058] The second number of transformers may be less than the fourth number of electrolysis systems.

[0059] The plurality of electrolysis systems may be included in a modular structure that further comprises: a set of power conversion units; and a set of separators. The plurality of electrolysis systems, the set of power conversion units, and the set of separators may be installed or installable in the modular structure prior to the modular structure being provided to and installed in the hydrogen production facility.

[0060] The hydrogen production facility may further comprise a second modular structure that is different than the modular structure. The second modular structure may comprise: a second plurality of electrolysis systems that is different than the plurality of electrolysis systems; a second set of power conversion units that is different than the set of power conversion units; and a second set of separators that is different than the set of separators. The second plurality of electrolysis systems, the second set of power conversion units, and the second set of separators may be installed or installable in the second modular structure prior to the second modular structure being provided to and installed in the hydrogen production facility.

[0061] The modular structure may comprise a first housing that comprises a first set of walls. The plurality of electrolysis systems may have a first distance measured between a first end of each electrolysis system of the plurality of electrolysis systems and at least one wall of the first set of walls. The plurality of electrolysis systems may have a second distance measured between a second end of each electrolysis system of the plurality of electrolysis systems and a third end of an adjacent electrolysis system of the plurality of electrolysis systems.

[0062] The second modular structure may comprise a second housing that comprises a second set of walls. The second plurality of electrolysis systems may havea third distance measured between a first end of each electrolysis system of the second plurality of electrolysis systems and at least one wall of the second set of walls. The second plurality of electrolysis systems may have a fourth distance measured between a second end of each electrolysis system of the second plurality of electrolysis systems and a third end of an adjacent electrolysis system of the second plurality of electrolysis systems. The first distance may be the same as the third distance. The second distance may be the same as the fourth distance.

[0063] According to an aspect, there is provided a hydrogen production facility comprising any or all of the following features: a first modular structure comprising: a first set of electrolysis systems; a first set of power conversion units; and a first set of separators, wherein the first set of electrolysis systems, the first set of power conversion units, and the first set of separators are installed or installable in the first modular structure prior to the first modular structure being provided to and installed in the hydrogen production facility; and a second modular structure that is different than the first modular structure, the second modular structure comprising: a second set of electrolysis systems that is different than the first set of electrolysis systems; a second set of power conversion units that is different than the first set of power conversion units; and a second set of separators that is different than the first set of separators, wherein the second set of electrolysis systems, the second set of power conversion units, and the second set of separators are installed or installable in the second modular structure prior to the second modular structure being provided to and installed in the hydrogen production facility.

[0064] The first modular structure may comprise a first housing that comprises a first set of walls. The first set of electrolysis systems may have a first distance measuredbetween a first end of each electrolysis system of the first set of electrolysis systems and at least one wall of the first set of walls. The first set of electrolysis systems may have a second distance measured between a second end of each electrolysis system of the first set of electrolysis systems and a third end of an adjacent electrolysis system of the first set of electrolysis systems.

[0065] The second modular structure may comprise a second housing that comprises a second set of walls. The second set of electrolysis systems may have a third distance measured between a first end of each electrolysis system of the second set of electrolysis systems and at least one wall of the second set of walls. The second set of electrolysis systems may have a fourth distance measured between a second end of each electrolysis system of the second set of electrolysis systems and a third end of an adjacent electrolysis system of the second set of electrolysis systems. The first distance may be the same as the third distance and the second distance is the same as the fourth distance.

[0066] The first modular structure and the second modular structure may be installed or installable in the hydrogen production facility to form a first structure and a second structure. The first structure may have a first interior and a first roof. The second structure may have a second interior and a second roof. The first structure and the second structure may be positioned or positionable offset from one another.

[0067] The first set of electrolysis systems and the second set of electrolysis systems may be positioned or positionable in the first interior and in the second interior. The first set of power conversion units and the second set of power conversion units may be positioned or positionable on the first roof and the second roof.

[0068] The first set of power conversion units may comprise a first set of transformers and a first set of rectifiers. The second set of power conversion units may comprise a second set of transformers and a second set of rectifiers. A ratio of transformers included in the first set of transformers and the second set of transformers to electrolysis systems included in the first set of electrolysis systems and the second set of electrolysis systems may be less than 1 .

[0069] According to a further aspect, there is provided a hydrogen production facility comprising one or more of the following features: a first structure having a first interior and a first roof; a second structure having a second interior and a second roof, the second structure positioned or positionable offset from the first structure; a plurality of electrolysis systems to electrolyze water using lye, the plurality of electrolysis systems positioned or positionable in the first structure and the second structure; and a set of power conversion units coupled or couplable with the plurality of electrolysis systems to provide power for facilitating electrolysis operations performed or performable by the plurality of electrolysis systems, the set of power conversion units positioned or positionable on the first structure and the second structure.

[0070] The plurality of electrolysis systems may comprise a first subset of electrolysis systems and a second subset of electrolysis systems. The first subset of electrolysis systems may be positioned or positionable in the first interior. The second subset of electrolysis systems may be positioned or positionable in the second interior. The set of power conversion units may comprise a first subset of power conversion units and a second subset of power conversion units. The first subset of power conversion units may be positioned or positionable on the first roof and coupled or couplable with thefirst subset of electrolysis systems. The second subset of power conversion units may be positioned or positionable on the second roof and coupled or couplable with the second subset of electrolysis systems.

[0071] The first subset of power conversion units may comprise a first set of transformers having a first number of transformers. The second subset of power conversion units may comprise a second set of transformers having a second number of transformers. The first subset of electrolysis systems may comprise a third number of electrolysis systems. The second subset of electrolysis systems may comprise a fourth number of electrolysis systems. The first number of transformers may be less than the third number of electrolysis systems. The second number of transformers may be less than the fourth number of electrolysis systems.

[0072] It will be appreciated that any or all of the above examples and / or examples in the description may be applied as a method.

[0073] According to an aspect, there is provided a method of operating a hydrogen production facility comprising any or all of the following steps: operating a plurality of electrolysis systems to electrolyze water using lye; circulating lye through a lye circulation system coupled with the plurality of electrolysis systems such that the lye is circulated among the plurality of electrolysis systems to facilitate electrolyzing the water; wherein the lye circulation system comprises: one or more pumps, wherein a number of the one or more pumps is less than a number of electrolysis systems of the plurality of electrolysis systems; and a lye cleaning subsystem positioned along the lye circulation system to clean the lye.

[0074] According to an aspect, there is provided a method of installing a hydrogen production facility comprising any or all of the following steps: installing a first set of electrolysis systems, a first set of power conversion units, and a first set of separators in a first modular structure prior to the first modular structure being provided to and installed in a hydrogen production facility; installing a second set of electrolysis systems that is different than the first set of electrolysis systems, a second set of power conversion units that is different than the first set of power conversion units, and a second set of separators that is different than the first set of separators in a second modular structure that is different than the first modular structure prior to the second modular structure being provided to an installed in the hydrogen production facility.

[0075] According to an aspect, there is provided a method of installing a hydrogen production facility comprising any or all of the following steps: providing a first structure having a first interior and a first roof; providing a second structure having a second interior and a second roof; positioning the second structure offset from the first structure; providing a plurality of electrolysis systems to electrolyze water using lye and positioning the plurality of electrolysis systems in the first structure and the second structure; providing a set of power conversion units and coupling the set of power conversion units with the plurality of electrolysis systems to provide power for facilitating electrolysis operations performed by the plurality of electrolysis systems; and positioning the set of power conversion units on the first structure and the second structure.

[0076] It will be appreciated that any or all of the aspects above or examples in the description may be applied to a method of operating a hydrogen production facility and / or a method of installation of a hydrogen production facility.Brief Description of the Drawings

[0077] One or more examples of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

[0078] FIG. 1 is a perspective view of an example of an electrolysis plant;

[0079] FIG. 2 is a set of views of portions of an electrolysis plant;

[0080] FIG. 3A is a schematic view of a system that includes set of electrolysis systems and FIG.3B is an image of a system that includes set of electrolysis systems;

[0081] FIG. 4 is a perspective view of an example of a modular structure that can be installed at the electrolysis plant;

[0082] FIG. 5A and FIG. 5B show simplified schematics of mutualization of components for the electrolysis plant; and

[0083] FIG. 6 is a schematic block diagram of a hydrogen production system that can be used in an electrolysis plant;

[0084] FIG. 7 is a schematic block diagram of a further hydrogen production system that can be used in an electrolysis plant;

[0085] FIG. 8 is a schematic block diagram of a lye purification system that can be used in an electrolysis plant; and

[0086] FIG. 9 is a schematic block diagram of a modularization of a hydrogen production system that can be used in an electrolysis plant.Detailed Description

[0087] Certain aspects and features of the present disclosure relate to an electrolysis plant incorporating mutualization and modularization for hydrogen production.The electrolysis plant can be used to generate green hydrogen, for example by separatinginput water into output hydrogen and output oxygen. The output hydrogen can be or include the green hydrogen that can be used as a fuel source, as an input to a subsequent process, or the like. The electrolysis plant, or one or more components thereof, may be mutualized, may be modularized, may be optimized, or any combination thereof to enhance, compared to other electrolysis plants that do not involve mutualization or modularization, a productivity of the electrolysis plant, an efficiency of the electrolysis plant, a safety of the electrolysis plant, ease of maintenance of modules of the plant or components thereof, ease of reconfiguration of the plant by replacement, addition or removal of modules, or any combination thereof. For example, lye cleaning in the electrolysis plant can be mutualized to simplify and make more efficient the techniques for cleaning lye, which may be or include alkaline material, used in electrolysis processes. In some examples, the lye may be or include electrolyte solution that can include potassium hydroxide, sodium hydroxide, other suitable alkaline material, or any combination thereof. Additionally or alternatively, blocks of electrolysis systems, or other suitable components of the electrolysis plant, can be modularized to enhance safety and maintenance or repair operations with respect to the electrolysis plant. In some examples, modularizing components can involve preassembly of the components, which may be standardized, to simplify a construction operation using the components.

[0088] The electrolysis plant may include a control center, a set of electrolysis systems, a set of heat exchangers, a set of pumps, a set of separators, a set of coolers, a set of circulators, and the like. In some examples, a set may include one item of the respective type or more than one item of the respective type. For example, a set of electrolysis systems may include only one electrolysis system or may include more thanone, such as two, three, four, or more than four, electrolysis systems. Additionally or alternatively, some of the above-mentioned sets may be combined to form a combined set. For example, the set of separators and the set of coolers may be combined, such as by being manufactured or installed together, to form a set of separators and coolers.

[0089] The electrolysis plant may be modular or may include modular components. For example, the set of heat exchangers, the set of separators, the set of coolers, and the like can be manufactured or installed together in a modular unit. The modular unit may be or include a pre-assembled building, or portion of a building, that includes the set of heat exchangers, the set of separators, the set of coolers, and the like pre-installed in optimized locations or arrangements. The modular unit can be installed, for example after pre-installing the components of the modular unit, in the electrolysis plant without needing to further install the set of heat exchangers, the set of separators, the set of coolers, and the like within the modular unit. The modular unit can enable a plug-and-play function for the electrolysis plant in which components of the electrolysis plant can be simply installed and used in the production of green hydrogen.

[0090] The electrolysis plant may be modularized, in that groups of subcomponents of the electrolysis plant may be grouped together in functional blocks, which may comprise components relating to a common functional aspect of the plant. Such functional blocks may also be known as product blocks. Examples of such functional blocks may include the following:

[0091] Electrolyzer block: An electrolyzer block typically comprises at least one electrolysis system, which may comprise at least one electrolyzer cell, and may comprise a stack of electrolyzer cells as described above, to form an electrolyzer stack.

[0092] Separation system block: A separation system block typically comprises at least one separation system comprising one or more separators, for separating gas suspended in a liquid from the liquid. This may be hydrogen suspended in liquid electrolyte, or oxygen suspended in liquid electrolyte. The separation system block may comprise at least one of a coalescer and a gravity separator. The separation system block may comprise at least one of a coalescer and / or a gravity separator for each of a hydrogen side of the system and an oxygen side of the system.

[0093] Lye Circulation block: A lye circulation block may comprise at least one pump and may further comprise at least one of a filter, a cooler, and an optional lye cleaning system. The lye circulation block may further comprise a plurality of fluid conduits arranged to circulate lye flow and direct it via at least one pump. The lye circulation may be mutualized and so one or more fluid conduits and / or the pump may be shared between a plurality of electrolyzer blocks or separation system blocks. The lye circulation block may provide one or more shared pumps, shared filters, shared coolers, or shared cleaning systems, shared between a plurality of electrolyzer blocks and / or a plurality of separation system blocks to provide mutualization of the systems. A lye circulation block can also therefore act as a lye mutualization block.

[0094] Power conversion block: A power conversion block may comprise one or more Transformers and one or more rectifiers.

[0095] Interconnecting block: An interconnecting block can act as a fluid conduit block and may comprise a plurality of fluid conduits, such as pipes, configured to connect, when located between other functional blocks, fluid systems of the respective functional blocks to one another. Interconnecting blocks may be connected to one another to createa fluid connection between functional blocks that are spaced apart by more than the distance over which one fluid connection block is configured to carry fluid between functional blocks. One or more interconnecting blocks may be installed after one or more of the functional blocks has been installed at a plant.

[0096] One or more of the functional blocks of the system may be comprised in a modular unit. A modular unit of the system may comprise a chassis arranged to mount and retain the components of the functional block in place within the modular unit both during transport to a site where the modular unit will be assembled, and during operation of the plant is an integral part of the electrolysis plant.

[0097] One or more of the modular units may be provided with a set of connection interfaces to enable assembly with one or more other modular units during assembly of an electrolysis plant comprising one or more of the modular units. Such connection interfaces may include one or more of: a) one or more hydraulic connections for connecting fluid conduits of subsystems of the electrolysis plant contained in the modular units to one another; b) one or more electrical connections for connecting electrical power and / or electrical signal conduits of subsystems of the electrolysis plant contained in the modular units to one another;

[0098] c) one or more instrumentation connections, which may include any necessary signal carrying conduits for instrumentation purposes, such as fluid or gas monitoring conduits, electrical or fibre-optic signal carrying conduits and the like. A modular electrolyzer unit may in particular comprise liquid conduits for directingelectrolyte to and / or from the cells or stacks of the electrolyzer block, gas conduits for directing gas (such as hydrogen or oxygen produced in the cell or cells) to and / or from the cells or stacks of the electrolyzer block, as well as fluid connection interfaces for connecting such conduits to and from parts of the plant external to the modular electrolyzer unit. Such external parts may include any other subsystem connected to the modular electrolyzer unit, such as a separator block and / or a lye mutualization or circulation block. The modular electrolyzer unit may comprise one or more electrical connections for connecting electrical power to the stacks or cells, and one or more installation connections, for connecting signal carrying conduits installation purposes for control of the system as described above.

[0099] A modular lye circulation or mutualization unit may comprise one or more fluid connection interfaces for connecting components of the lye circulation or mutualization unit to one or more fluid connection interfaces of one or more modular electrolyzer units. The modular lye circulation or mutualization unit may further comprise one or more external electrical connections for providing electrical power or signals to electrical components comprised within the modular lye circulation or mutualization unit, and / or one or more external instrumentation connections for carrying control signals to or from one or more components of the modular lye circulation or mutualization unit to or from one or more components of the plant that are external to the modular lye circulation or mutualization unit. A modular lye circulation or mutualization unit may comprise one or more pumps. The number of pumps may be less than the number of fluid connection interfaces for connection to one or more fluid connection interfaces of one or more modular electrolyzer units.

[0100] A modular power conversion unit may comprise one or more electrical connections for receiving electrical power from one or more modular electrolyzer units, and one or more electrical control signal connections or instrumentation connections for receiving and / or delivering electrical control or instrumentation signals to or from other components of the plant which are located outside of the modular power conversion unit.

[0101] Modular units may be removed after assembly of the plant, optionally after operation of the plant and may be replaced with new generation modular units having connection interfaces of which at least one is the same as a connection interface of the removed modular unit.

[0102] The electrolysis plant may include mutualized components, processes, or the like. Mutualization of components, processes, or the like can involve using fewer components, such as by sharing the components, to perform the same process, can involve performing a single process on, or with, more than one component, or the like. In some examples, the electrolysis plant can include lye mutualization, which can involve mutualizing heat exchangers, pumps, circulation lines, and the like for the set of electrolysis systems. For example, instead of having one pump for each electrolysis system, one pump can be used for all of the electrolysis systems, or for a subset of the electrolysis systems in which the subset includes more than one electrolysis system, in the electrolysis plant. Additionally or alternatively, instead of having one heat exchanger for each electrolysis system, one heat exchanger can be used for all of the electrolysis systems, or a subset of the electrolysis systems in which the subset includes more than one electrolysis system, in the electrolysis plant. In another example relating to mutualization in the electrolysis plant, instead of having one separator for eachelectrolysis system, one separator can be used for all of the electrolysis systems, or a subset of the electrolysis systems in which the subset includes more than one electrolysis system, in the electrolysis plant. In another example relating to mutualization in the electrolysis plant, instead of having one controller, such as a programmable logic controller (PLC), for each electrolysis system, one controller can be used for all of the electrolysis systems, or for a subset of the electrolysis systems in which the subset includes more than one electrolysis system, in the electrolysis plant. Other suitable examples of mutualization can be implemented in the electrolysis plant.

[0103] In some examples, lye cleaning in the electrolysis plant can be achieved inline, in situ, or a combination thereof. References to lye cleaning refer to processes or devices that are configured for maintaining the purity and effectiveness of the lye. For example, the primary function of a lye cleaning process or device is to clean the lye and improve its suitability for recirculating into the system, for example by removing solid impurities, adding other components to maintain concentration or the like. It will be understood that lye cleaning is different to product separation devices or processes in the electrolysis plant, for example to separate hydrogen or oxygen products from the lye. In this case, the primary function of a separation device or process is to obtain high-purity products. In this way, for the purposes of the present disclosure, product separation devices are not considered as configured to clean the lye. In some cases, lye cleaning may occur downstream of product separation devices or processes, for example a lye cleaning subsystem may be provided in between product separators and electrolysis systems, such that lye passes from the product separators to the electrolysis systems via the cleaning subsystem.

[0104] In-line lye cleaning can involve installing one or more filters, one or more membranes, resin, ferrite, apatite, or the like along a lye circulation line included in the electrolysis plant. The one or more filters, one or more membranes, the resin, the ferrite, the apatite, or the like can be used to clean the lye used to facilitate production of the green hydrogen while in use, such as while the lye is being circulated. In some examples, the one or more filters, one or more membranes, the resin, the ferrite, the apatite, or the like can be used to clean the lye, such as by removing contaminants, at operational conditions of the electrolysis process. The operational conditions may include an elevated temperature, an elevated pressure, an elevated pH, a velocity of lye travelling through circulation lines, or any combination thereof for producing green hydrogen via electrolysis. As used herein, the term “elevated temperature” and “elevated pressure” may refer to temperatures and pressures, respectively, that are greater than ambient temperature. The term “elevated pH” may refer to a pH greater than neutral, for example greater than 7. In some examples, the elevated temperature may be from approximately 30 °C to approximately 500 °C, or other suitable maximum temperature in which the lye is a liquid, the elevated pressure may be from approximately one bar to approximately 100 bar, such as between approximately eight barg and approximately 40 barg, and the elevated pH may be from approximately 8 to approximately 14, though other suitable examples of elevated temperature, elevated pressure, elevated pH, or a combination thereof are possible.

[0105] In situ lye cleaning may involve using a storage tank coupled with the lye circulation line to clean the lye. For example, one or more filters, one or more membranes, the resin, the ferrite, the apatite, one or more pumps, and the like can be installed in thestorage tank for cleaning the lye. The storage tank can be installed adjacent to the lye circulation line. For example, the lye circulation line may be coupled with the storage tank, but the lye circulating through the lye circulation line may not be forced to go into the storage tank after each pass of the lye through the lye circulation line. For example, the lye circulation line may have a valve that can be selectively opened to allow the lye to be passed from the lye circulation line into the storage tank, from the storage tank into the lye circulation line, or a combination thereof. While in the storage tank, the lye can be cleaned, such as via the one or more filters, the one or more membranes, the one or more pumps, and the like. Conditions in the storage tank may be similar but not identical to operational conditions within the lye circulation line. For example, while the operational conditions within the lye circulation line may involve an elevated temperature, an elevated pressure, an elevated pH, or a combination thereof, the conditions in the storage tank may involve an ambient temperature and an elevated pH. The one or more filters, the one or more membranes, the resin, the ferrite, the apatite, the one or more pumps, and the like can clean the lye under the conditions in the storage tank, and cleaned lye can be conveyed back into the lye circulation line to facilitate production of green hydrogen via electrolysis. In some examples, all of the lye can be cleaned, or a subset of all of the lye can be cleaned by bypassing from more than approximately 0% to approximately 100% of the flow of the lye.

[0106] In some examples, and due to corrosion of metallic materials with lye and oxygen, the lye circulation line, other lye conveyance lines, valves associated therewith, or any combination thereof may include non-metallic materials such as reinforced polymers, or metallic materials lined with polymer, that may be applicable for industrialapplications. Additionally or alternatively, the lye circulation line may not include metallic materials such as iron and other metals that can impact a performance of the electrolysis systems.

[0107] In some examples, in-line lye cleaning and in situ lye cleaning may be exclusive or may be inclusive. For example, the in-line lye cleaning and the in situ lye cleaning may be exclusive such that one or the other, but not both, are performed in the electrolysis plant. Additionally or alternatively, the in-line lye cleaning and the in situ lye cleaning may be inclusive such that both the in-line cleaning and the in situ cleaning may be performed in the electrolysis plant, for example one after the other or substantially contemporaneously with respect to one another. The lye circulation line may include the one or more filters, the one or more membranes, the resin, the ferrite, the apatite, or the like that can clean the lye inline, and the lye circulation line may be coupled with the storage tank that can perform in situ cleaning of the lye. Additionally or alternatively, inline lye cleaning, in situ lye cleaning, or a combination thereof can be performed with mutualized lye circulation loops. For example, mutualization including lye cleaning can involve a cleaning pathway shared through lye circulation lines from multiple electrolysis systems or can involve lye circulation lines from multiple electrolysis systems going into separate storage tanks for in situ lye cleaning. Lye cleaning may include any aspect or feature of lye purification as described herein.

[0108] These illustrative examples are given to introduce the reader to the general subject matter discussed herein and are not intended to limit the scope of the disclosed concepts. The following sections describe various additional features and examples with reference to the drawings in which like numerals indicate like elements, and directionaldescriptions are used to describe the illustrative aspects, but, like the illustrative aspects, should not be used to limit the present disclosure.

[0109] FIG. 1 is a perspective view of an example of an electrolysis plant 10 that can include mutualized components, modularized components, optimized components, and the like for generating green hydrogen and for performing other suitable electrolysis operations according to one example of the present disclosure. As illustrated in FIG. 1 , the electrolysis plant 10 can include a set of electrolysis systems 12, gas separators and coolers 14, a centralized control system 16, a set of transformers 18, a set of rectifiers 20, a circulation system 22, hydrogen export compressors 24, and a hydrogen flare unit 26. Additional or alternative components are possible to include in the electrolysis plant 10. The set of transformers 18 and / or the set of rectifiers 20 may be referred to as a set of power conversion units in some arrangements. In some arrangements, one or more of the components may be omitted from the electrolysis plant 10.

[0110] The centralized control system 16 may include a single control system, such as a programmable logic controller (PLC), that can control the operations that can be performed by the electrolysis plant 10. In some examples, the centralized control system 16 may include more than one control system, such as more than one PLC, but each control system included in the centralized control system 16 may control more than one operation that can be performed by the electrolysis plant 10. In some examples, a single PLC can be included in the centralized control system 16, and the single PLC can control each electrolysis operation, or any subset thereof that includes more than one operation, that can be performed by the set of electrolysis systems 12 included in the electrolysis plant 10. In some examples, the centralized control system 16 may include an interfacethat can provide users with the capability to control, such as alter, halt, commence, etc., more than one operation that can be performed by the electrolysis plant 10 or any components thereof. In some examples, the interface may provide options to (i) halt more than one electrolysis operation to perform maintenance, repair, or replacement on the respective electrolysis systems 12, and (ii) then to commence the halted operations once the maintenance, repair, or replacement is performed. Other examples of control by the centralized control system 16 are possible.

[0111] The set of electrolysis systems 12 can include one or more electrolysis systems 44 (see FIG. 3). The set of electrolysis systems 12 can include one electrolysis system 44, two electrolysis systems 44, three electrolysis systems 44, four electrolysis systems 44, or more than four electrolysis systems 44. Each electrolysis system 44 of the set of electrolysis systems 12 may be arranged to receive inputs or feed streams, such as water, lye, which may also include water, energy, and the like, and generate outputs or product streams such as hydrogen, oxygen, and the like. Each electrolysis system 44 may include one or more electrolyzer cells. A cell may have an anode, a cathode and a membrane. The membrane may separate an oxygen side of the system from a hydrogen side of the system. The electrolyzer cell is configured to electrolyze water using an electrolyte to generate product streams containing hydrogen and oxygen. In some cases, an electrolysis system 44 may include a plurality of electrolyzer cells connected to form one or more electrolyzer stacks. It will be appreciated that one or more electrolysis systems 44 of the set 12 may be configured differently from one another, e.g. may operate under different conditions. One or more electrolysis systems 44 typically refers to a cell of a stack comprising a plurality of cells. The plant or its sub-systems of modules mayinclude additional components, e.g. piping, valves, pumps, heating or cooling systems, storage tanks or the like. An electrolysis system as described in any aspect of this disclosure can be termed a water electrolyzer.

[0112] In some examples, the set of electrolysis systems 12 can be separated into a first subset of electrolysis systems 12a and a second subset of electrolysis systems 12b, and the first subset 12a can be positioned in a first building 28, while the second subset 12b can be positioned in a second building 30 that is offset from the first building. It will be understood that the term “offset” can mean that the buildings are positioned in such a way that they do not occupy the same space, for example, the buildings are displaced from one another along at least one axis. For example, the first building may be set back or forward or shifted to the side relative to the second building. The first and second buildings 28, 30 may be separate from each other as shown in Figure 1 (for example sharing no walls) or may share one or more walls. The described offset is provided for reliability reasons to avoid a fault with one building or unit affecting a neighbouring building or unit. The desired distance may be linked to volumes of separation vessels in a building or unit. Larger volumes of vessels may result in larger distances being desirable. It can be desirable to have a distance of between 1 and 15 metres between two separator systems, for example.

[0113] The subsets of electrolysis systems 12a, 12b may include an equal number of electrolysis systems 44. In some examples in which there are 20 electrolysis systems 44 included in the set of electrolysis systems 12, the first subset 12a can include 10 electrolysis systems 44, and the second subset 12b can include 10 electrolysis systems 44. Other examples, such as those in which the first subset 12a and the second subset12b include different numbers of electrolysis systems 44 individually and with respect to one another, are possible.

[0114] The first building 28 and the second building 30 may each have an interior 32 and a roof 34 (see Fig. 2). The first subset of electrolysis systems 12a may be positioned in the interior 32 of the first building 28, and the second subset of electrolysis systems 12b may be positioned in the interior 32 of the second building 30. The first subset 12a and the second subset 12b may each be coupled with or otherwise associated with transformers 18 and rectifiers 20. For example, the first subset of electrolysis systems 12a can be coupled with a first subset of transformers 18a and a first subset of rectifiers 20a, and the second subset of electrolysis systems 12b may be coupled with a second subset of transformers 18b and a second subset of rectifiers 20b. The first subset of transformers 18a and the second subset of transformers 18b may form the set of transformers 18, and the first subset of rectifiers 20a and the second subset of rectifiers 20b may form the set of rectifiers 20. The first subset of transformers 18a and / or the first subset of rectifiers 20a may be referred to as a first set of power conversion units. The second subset of transformers 18b and / or the second subset of rectifiers 20b may be referred to as a second set of power conversion units. The first subset of transformers 18a and / or the first subset of rectifiers 20a may be positioned on the roof 34 of the first building 28, and the second subset of transformers 18b and / or the second subset of rectifiers 20b may be positioned on the roof 34 of the second building 30. In some examples, at least a portion of the first subset of transformers 18a, a portion of the second subset of transformers 18b, or a combination thereof can be positioned on a floor of the respective building. In general, one or more of the electrolysis systems may be locatedinside one of the first or second buildings. Any component of the separation systems of the plant may be located either inside or outside of the first or second buildings, including on the first or second buildings.

[0115] In some examples, the set of transformers 18, the set of rectifiers 20, or a combination thereof, such as a power conversion unit, which may also include a polarization unit to prevent a reverse current in the event of a sudden shut down, may be mutualized. Mutualizing the set of transformers 18, the set of rectifiers 20, or a combination thereof may involve having a ratio of transformers-to-electrolysis systems, of rectifiers-to-electrolysis systems, or a combination thereof that is less than one, which may indicate that more than one electrolysis system 44 can be serviced by one transformer, one rectifier, or a combination thereof.

[0116] Put another way, the number of transformers in the first subset of transformers 18a may be lower than the number of electrolysis systems 44 in the first subset of electrolysis systems 12a. The number of transformers in the second subset of transformers 18b may be lower than the number of electrolysis systems 44 in the second subset of electrolysis systems 21 b. The number of rectifiers in the first subset of rectifiers 20a may be lower than the number of electrolysis systems 44 in the first subset of electrolysis systems 12a. The number of rectifiers in the second subset of rectifiers 20b may be lower than the number of electrolysis systems 44 in the second subset of electrolysis systems 21 b. In other examples, the number of transformers may be less than the number of rectifiers.

[0117] Examples can be envisaged in which, within a plant or within a subsystem of a plant:a. a number of rectifiers is the same as a number of electrolyzer systems; b. a number of rectifiers is less than a number of electrolyzer systems; c. a number of transformers is less than a number of rectifiers; d. a number of gas separators or separator blocks is less than a number of power conversion units and / or a number of electrolyzer systems; e. or any combination of the above.

[0118] Configuration b. above may in some arrangements be implemented when the electrolyzer systems or ‘stacks’ are electrically connected in series. In other configurations the electrolyzer systems may be electrically connected in parallel.

[0119] Generally, the number of electrolyzer systems may be the same as or greater than a number of separator units or modules, such that a first number of electrolyzer systems is greater than a number of separation units or modules to which the electrolyzer systems are connected in the plant or a subsystem of a plant.

[0120] In some examples, a single transformer, a single rectifier, or a combination thereof can be positioned on the roof 34 of the first building 28 to provide respective service for the first subset of electrolysis systems 12a, and a single transformer, a single rectifier, or a combination thereof can be positioned on the roof 34 of the second building 30 to provide respective service for the second subset of electrolysis systems 12b. In this arrangement, at least one of the first and second sets of transformers 18a, 18b includes a single transformer and at least one of the first and second sets of rectifiers 20a, 20b includes a single rectifier. In other examples, one transformer, such as a 20 MW transformer, may be used to provide service, such as power, for approximately four electrolysis systems 44, which each may be 5 MW. In this example, the approximatelyfour electrolysis systems 44 may be arranged in series, in parallel, or partially in series and partially in parallel. Other suitable examples, such as partial mutualization of the transformers, of the rectifiers, or a combination thereof, are possible.

[0121] The gas separators and coolers 14 can be positioned adjacent to the first building 28, to the second building 30, or to a combination thereof. For example, the gas separators and coolers 28 can include a first subset of gas separators and coolers 14a and a second subset of gas separators and coolers 14b. The first subset of gas separators and coolers 14a can be positioned adjacent to the first building 28, and the second subset of gas separators and coolers 14b can be positioned adjacent to the second building 30. The first subset of gas separators and coolers 14a can provide functionality, such as separating hydrogen and oxygen, cooling the separated gas, or the like, for the first subset of electrolysis systems 12a. In this arrangement, the first subset of gas separators and coolers 14a is operatively coupled to the first subset of electrolysis systems 12a. The second subset of gas separators and coolers 14b can provide functionality, such as separating hydrogen and oxygen, cooling the separated gas, or the like, for the second subset of electrolysis systems 12b. In this arrangement, the second subset of gas separators and coolers 14b is operatively coupled to the second subset of electrolysis systems 12b. In some examples, the first subset of gas coolers and separators 14a, the second subset of gas coolers and separators 14b, or a combination thereof may be positioned on a raised structure that can allow personnel or other entities to be or move underneath or behind the first subset of gas coolers and separators 14a, the second subset of gas coolers and separators 14b, or a combination thereof.

[0122] The set of electrolysis systems 12, the set of transformers 18, the set of rectifiers 20, the gas separators and coolers 14, the first building 28, the second building 30, or any combination thereof may be modular. For example, at least some of the set of electrolysis systems 12, the set of transformers 18, the set of rectifiers 20, the gas separators and coolers 14, the first building 28 and the second building 30 may be premanufactured and pre-installed prior to being provided to the electrolysis plant 10. In some examples, a first section of the first building 28 that includes a portion of the first subset of electrolysis systems 12a, a portion of the first subset of transformers 18a, and a portion of the first subset of rectifiers 20a can be pre-formed as a first modular structure prior to being provided to the electrolysis plant 10, and, in response to being provided to the electrolysis plant 10, the first modular structure can be simply installed into a predetermined location of the electrolysis plant 10. In some examples, additional or alternative components, such as the gas coolers and separators 14, of the electrolysis plant 10 can be included in the first modular structure or in other suitable modular structures.

[0123] The circulation system 22 can be positioned adjacent, or otherwise proximate, to the first building 28, the second building 30, or a combination thereof. In some examples, the circulation system 22 may be or include a lye circulation and cooling system that can provide lye to the set of electrolysis systems 12 to facilitate electrolysis reactions. The lye, which may be or include an alkaline material, such as sodium hydroxide, potassium hydroxide, or other suitable alkaline materials, can be circulated to the set of electrolysis systems 12 to cause hydrogen to be separated from oxygen in input water.

[0124] The circulation system 22 may be mutualized with respect to the set of electrolysis systems 12. For example, the circulation system 22 may circulate the lye to more than one electrolysis system 44 of the set of electrolysis systems 12. In some examples, the circulation system 22 may be fully mutualized, which may involve a single circulation system, such as a single pump, one set of circulation lines, and the like, that can circulate the lye to each electrolysis system 44 of the set of electrolysis systems 12. Additionally or alternatively, the circulation system 22 may provide lye cooling for each electrolysis system 44 of the set of electrolysis systems 12.

[0125] FIG. 2 is a set of views of portions of the electrolysis plant 10 that can include mutualized components, modularized components, optimized components, and the like for generating green hydrogen and for performing other suitable electrolysis operations according to one example of the present disclosure. As illustrated in FIG. 2, four views are shown to highlight various features of the electrolysis plant. For example, a first view, in the upper-left of FIG. 2, illustrates a first building 28 of the electrolysis plant 10, a second view, in the upper-right of FIG. 2, illustrates a modular feature of the electrolysis plant 10, a third view, in the bottom-left of FIG. 2, illustrates a mutualization feature of the electrolysis plant 10, and a fourth view, in the bottom-right of FIG. 2, illustrates an optimization feature of the electrolysis plant 10. Other suitable views of the electrolysis plant 10 are possible.

[0126] In the first view, the first building 18 of the electrolysis plant 10 is illustrated. The first building 28 may house at least a subset of the set of electrolysis systems 12 and associated components for providing functionality for the at least the subset of the set of electrolysis systems 12. For example, the first building 28 can house the first subset 12aof electrolysis systems 12, the first subset of transformers 18a, the first subset of rectifiers 20a, other suitable components, or any combination thereof. In some examples, the first building 28 can include the first subset of electrolysis systems 12a in an interior 32 of the first building 28 and can include the first subset of transformers 18a and the first subset of rectifiers 20a on a roof 34 of the first building 28. Including the first subset of transformers 18a and the first subset of rectifiers 20a on the roof 34 can allow the set of electrolysis systems 12a to be optimally arranged in the interior 32 of the first building 28. For example, a number of electrolysis systems 44 in the interior 32 can be maximized, spacing between the electrolysis systems 44 can be optimized to ensure compliance and safety, maintenance access, and the like. Additionally or alternatively, including the first subset of transformers 18a and the first subset of rectifiers 20a on the roof 34 can allow free access to the first subset of electrolysis systems 12a. Free access to the first subset of electrolysis systems 12a can make maintenance, repair, and replacement of the first subset of electrolysis systems 12a easier, safer, quicker, possible, or the like. In some arrangements, the subsets of transformers 18a, 18b and the subsets of rectifiers 20a, 20b may be located inside an upper story or floor of the respective building 28, 30 relative to the subsets electrolysis systems 12a, 12b. In this way, the subsets of electrolysis systems 12a, 12b, the subsets of transformers 18a, 18b and the subsets of rectifiers 20a, 20b may all be located in the respective building interior 32, but on separate floors. In one example, the subsets of electrolysis systems 12a, 12b may be located on the ground floor of the building 28, 30 while the subsets of one or more transformers 18a, 18b and / or the subsets of one or more rectifiers 20a, 20b are located on the first floor or higher of thebuilding 28, 30 or higher (for example, on a second floor, a third floor or more, of the building).

[0127] In the second view of Figure 2, one possible example of a modular feature of the electrolysis plant 10 is illustrated. The example of the modular feature is a modular unit which may be or may comprise a structure 36 and which may include gas separators and optionally one or more coolers 14. The gas coolers and / or separators 14 can be positioned adjacent, or otherwise proximate, to the set of electrolysis systems 12 to provide separation and cooling functionality for each electrolysis system 44 of the set of electrolysis systems 12. The gas coolers and / or separators 14 can be located on a roof or a second (or further) floor of the modular structure 36. Additionally or alternatively, the modular structure 36 may include a mutualized drainage circuit 38 and an optional pit 39 to recover lye in case of leakage. The modular structure 36 can include a retaining structure 40 and at least a subset 14a of the gas separators and coolers 14. The retaining structure 40 may provide a scaffold or may otherwise provide at least a partial surface onto which the subset of the gas separators and coolers 14a can be positioned. In some examples, the modular structure 36 can cause the subset of gas separators and coolers 14a to be raised to provide free access under the subset of gas separators and coolers 14a and, in some cases, to a side of the set of electrolysis systems 12a. The modular structure 36 can be pre-formed prior to being provided to the electrolysis plant 10. For example, the retaining structure 40 can formed at a manufacturing location, and the subset of gas separators and coolers 14a can be installed in the retaining structure at the manufacturing location, or at a separate location, prior to being provided to the electrolysis plant 10.

[0128] In some examples, the modular structure 36 can be combined with at least a portion of the first building 28. For example, a portion of the first building 28 can be preformed prior to being provided to the electrolysis plant 10, and the portion of the first building can be combined with, such as affixed to, coupled with, etc., the modular structure 36 to form a combined modular structure. The combined modular structure can be provided to the electrolysis plant 10 at which the combined modular structure can be easily installed without needing to install individual components such as individual electrolysis systems 12, gas separators or coolers 14, etc. Other suitable examples of modularization of the components of the electrolysis plant 10 are possible.

[0129] In the third view, one possible example of a mutualization feature of the electrolysis plant 10 is illustrated. The third view illustrates a circulation system 22 of the electrolysis plant 10, though other suitable components or features, such as transformers, separators, hydrogen and oxygen gas washing and cooling, a vent or flaring system, etc., can additionally or alternatively be mutualized, for example fully or partially, in the electrolysis plant 10. The circulation system 22 may be or include a lye circulation system that can provide lye to the set of electrolysis systems 12 to facilitate one or more electrolysis operations such as to generate green hydrogen. In some examples, the circulation system 22 may include one or more pumps, one or more circulation lines or conduits, one or more storage tanks, and the like to circulate the lye to the set of electrolysis systems 12. Mutualizing the circulation system 22 may involve using one circulation system 22, which may include a pump, one or more filters, a circulation loop, and the like in which the circulation loop can include conduits or other means for transporting the lye, to circulate lye to more than one electrolysis system 44. For example,and instead of having one circulation system for each electrolysis system 44, one circulation system 22 can provide lye to, and receive lye from, more than one electrolysis system 44 of the set of electrolysis systems 12. Full mutualization of the circulation system 22 may involve having one circulation system that circulates the lye among all electrolysis systems 44 of the set of electrolysis systems 12.

[0130] In some examples, optimized or otherwise enhanced cleaning procedures or arrangements can be used for the circulation system 22 such as with the mutualization of the circulation system 22 or without the mutualization of the circulation system 22. The circulation system 22 may include a set of circulation lines configured to convey the lye to the electrolysis systems 44. The circulation system 22 may include a cleaning subsystem (not shown) configured to clean the lye. Potential configurations of the cleaning subsystem have been discussed above. For example, in-line lye cleaning, in situ lye cleaning, or the like can be performed in the circulation system 22. In-line lye cleaning can involve positioning membranes, filters, the resin, the ferrite, the apatite, or the like along the lye circulation lines to clean the lye while in operation. The membranes, filters, and the like may clean the lye at operational conditions, which may involve elevated temperature, elevated pH, or a combination thereof. Additionally or alternatively, one or more storage or sequestration tanks can be positioned in the electrolysis plant 10 and coupled with the lye circulation lines. The storage tanks can be positioned adjacent or proximate to the lye circulation lines, and the storage tanks may include (for example, contain) membranes, filters, the resin, the ferrite, the apatite, pumps, and other components that can be used to clean the lye. The lye can be provided, such as via one or more valves on the lye circulation lines, to the storage tank, which can facilitatecleaning the lye at conditions that are similar, but not identical, to the operational conditions. For example, the conditions may involve ambient temperature and elevated pH. The storage tanks may be referred to as cleaning tanks in some cases.

[0131] In the fourth view, one possible example of an optimized layout of the electrolysis plant 10 is illustrated, though other suitable optimizations associated with the electrolysis plant 10 are possible. The optimized layout can involve positioning the first building 28 and the second building 30, along with the components included therein and coupled thereto, to allow mutualization, easy maintenance, repair, and replacement, and the like with respect to the electrolysis plant 10. For example, positioning the first building 28 offset from, and facing in an opposite direction with respect to, the second building 30 can allow mutualization of the circulation system 22, the gas separators and coolers 14a, 14b, and the like. For example, a larger number of transformers and rectifiers can be mutualized compared to other arrangements of the first building 28 and the second building 30, and / or the circulation system 22 can be mutualized for more electrolysis systems 44 compared with the other arrangements. Additionally or alternatively, positioning the first building 28 offset from, and facing in an opposite direction with respect to, the second building 30 can optimize maintenance, repair, and replacement operations with respect to the electrolysis systems 44 and related components. For example, positioning the first building 28 offset from, and facing in an opposite direction with respect to, the second building 30 can allow free access to the electrolysis systems 44 and related components and can improve a safety and efficiency of maintenance, repair, and replacement operations with respect to the electrolysis systems 44 and related components.

[0132] FIG. 3A is a schematic view of a system that includes set of electrolysis systems 12. Figure 3A illustrates with arrows how, with appropriate arrangement of the electrolysis systems with respect to the remaining components of the system, the electrolysis systems labelled S in the figure can be more easily removed for maintenance or repair. This may be achieved by following the direction of arrow A to remove electrolysis system or systems out from an enclosure, which may be an enclosure located below a power conversion unit. Pathways of sufficient width may be provided for the electrolysis system or systems to exit a building in which they are located for maintenance or replacement.

[0133] FIG. 3B shows an interior 32 of a building of the plant 10 (e.g. the first building 28 or the second building 30). The building may be part of a modular structure or may be a modular structure that comprises modular elements such as modular units described herein. As illustrated in FIG. 3, the set of electrolysis systems 12 can be in arrangements that can optimize, such as maximize, safety, compliance, and the like with respect to the set of electrolysis systems 12. The arrangement can involve a first distance (labelled “i” in FIG. 3B) between each electrolysis system 44 and a wall 42 of a building 28, 30 in which the set of electrolysis systems 12 is disposed. The first distance may be measured between a first end of each electrolysis system 44 and a wall 42 of the building 28, 30. This distance may provide a suitable walkway and access for plant operators between the electrolysis systems 44 and the wall 42. The arrangement can involve a second distance (labelled “ii” in FIG. 3) between each electrolysis system 44 and an adjacent electrolysis system 44. The second distance may be measured between a second end of each electrolysis system 44 and a third end of an adjacent electrolysissystem 44. This may provide for access to each individual electrolysis system 44. The first distance may be one meter, though other suitable distances, such as less than one meter or more than one meter, up to 5 meters or 10 meters are possible. Additionally or alternatively, the second distance may be 1.8 meters, or 1.8 meters plus or minus 0.5 meters, though other suitable distances, such as less than one meter or more than one meter, are possible. The first distance and the second distance can allow personnel to freely access the set of electrolysis systems 12 for maintenance, repair, or replacement operations without causing excessive risk of damage to equipment, personnel, or the like. Additionally or alternatively, the first distance and the second distance can allow a maximum number of electrolysis systems 44 to be included in a respective building 28, 30 without causing excessive risk of damage to equipment, personnel, or the like. Additionally or alternatively, an integrated safety risk quantification analysis can be performed with respect to the layout of components of the electrolysis plant 10 to optimize safe distances. In some arrangements, the first distance and the second distance is the same in both subsets of electrolyzer systems 12a, 12b in each respective building 28, 30.

[0134] FIG. 4 is a perspective view of an example of a modular structure 46 that can be installed at the electrolysis plant 10 according to one example of the present disclosure. The modular structure 46 can include a set of electrolysis systems 12 and a set of power conversion units (for example a set of transformers 18 and a set of rectifiers 20), gas separators and coolers 14, a first building 28, a second building 30, or any combination thereof. In some examples, the electrolysis plant 10 can include (i) a first type of modular structure that includes a first subset of components from the aboverecited list and (ii) a second type of modular structure that includes a second subset, thatis different than the first subset, of components from the above-recited list. At least some of the set of electrolysis systems 12, the set of transformers 18, the set of rectifiers 20, the gas separators and coolers 14, the first building 28 and the second building 30 may be pre-manufactured and pre-installed prior to being provided to the electrolysis plant 10. In some examples, a first section of the first building 28 that includes a portion of the first subset of electrolysis systems 12a, a portion of the first subset of transformers 18a, and a portion of the first subset of rectifiers 20a can be pre-formed as a first modular structure 46 prior to being provided to the electrolysis plant 10, and, in response to being provided to the electrolysis plant 10, the first modular structure 46 can be simply installed into a predetermined location of the electrolysis plant 10. In some examples, additional or alternative components, such as the gas coolers and separators 14, for example the first subset of gas coolers and separators 14a, of the electrolysis plant 10 can be included in the first modular structure 46, such as above the electrolysis systems 44, or in other suitable modular structures.

[0135] FIG. 5A and 5B show a simplified schematic of mutualization of components for the electrolysis plant 10. As illustrated, electrolysis systems 44, such as systems 1-5 & N, which can be an unbound number or electrolysis systems 44, can be coupled with separators 14. In FIG. 5A, which may illustrate no mutualization of the separators, each electrolysis system 44 may be coupled with a different set of separators 14, which may include a hydrogen separator and an oxygen separator. In Figures 5A and 5B, the labels have the following meanings: T is a temperature, Q is a mass flow rate, P is a pressure, Fe can imply an iron content. More generally, iron content Fe may imply or be replaced with any pollutant or impurities. The symbols T1 , Q1 , P1 , Fe1 , imply a particular amountor level of that property associated with the first electrolysis system in a series of N electrolysis systems. TN, QN, PN, FeN, PaN, PcN can imply a particular amount or level of that property associated with an Nth electrolysis system in a series. PaN means pressure on the anodic side in the Nth separator, PcN means pressure on the anodic side in the Nth separator.

[0136] In FIG. 5B, which may illustrate full mutualization of the separators 14, each electrolysis system 44 may be coupled with a common set of separators 14. Partial mutualization, such as mutualization between no mutualization and full mutualization, of the separators is also possible for the electrolysis plant. These figures also indicate an example of mutualization of the circulation system 22, in which a circulation system 22 is common to a plurality of electrolysis systems 44.

[0137] FIG. 6 is a schematic block diagram of a hydrogen production system 100 that can be used in an electrolysis plant 10 according to one example of the disclosure. The schematic block diagram may represent one electrolysis process that can be performed by the electrolysis plant 10, or the components thereof, though other suitable electrolysis processes, including multiple iterations of the process performed by the illustrated schematic block diagram, can be performed by the electrolysis plant 10. For example, the schematic block diagram illustrated in FIG. 6 may be a general representation of a process that can be performed at the electrolysis plant 10, can be a simplified version of a process that can be performed at the electrolysis plant 10, and the like.

[0138] FIG. 6 includes multiple electrolyzer, or electrolysis, systems 44, such as System 1 , System n, etc., which may form the set of electrolysis systems 12. The system100 includes a pump 48, coalescers 50a, 50b, and separators 52a, 52b, such as a hydrogen-recovery vessel 52a labeled as H2 and an oxygen-recovery vessel 52b labeled as 02, though other or additional suitable components are possible. In some examples, the system pressure differential can be disconnected from the gas phase pressure differential of both separation vessels 52a, 52b of the system 100. The pressure drops in the lines can be controlled upstream of the separation, such as via the collector, which can be done by using a suitably configured separation device or by properly sizing the pipeline network. The hydrogen separator 52a and the oxygen separator 52b can be connected between each other through a pressure balancing line 54. The pressure balancing line 54 can enter at the lowest point of the separators 52a, 52b or the coalescers 50a, 50b to allow the liquid to flow both ways from a side to another and to prevent any direct displacement of the gaseous phase from one vessel to the other. The pressure at the inlet of the separators 52a, 52b can be coupled to the liquid level in the separator. The separator 52a, 52b inlet can be at the bottom or near the bottom of the separator. The coalescer 50a, 50b inlet can be at the bottom or near the bottom of the coalescer 50a, 50b. If a distributor is considered, there can be a hole at its base. Electrolyte pumping downstream separation can be mutualized and split before entering the cell. The balancing line 54 and the mutualization line upstream pump can be the same.

[0139] The electrolyte can be mixed from both sides. The electrolyte can be gas- free to minimize hydrogen transferring to oxygen and oxygen transferring to hydrogen, for example for safety reasons. Potassium hydroxide or other lye in solution can stabilize the gas microbubbles, which can prevent the microbubbles from fusing and forming larger bubbles that can rise quickly to the surface. Targeted purity may otherwise involveirrational residence time and separator dimensions to allow for sufficient separation in a gravity separator device. In some examples, the separation can be split into a primary separator 52a, 52b and a coalescer 50a, 50b.

[0140] The primary separator 52a, 52b can remove the bulk of gas and the large bubbles from the electrolyte. The primary separator 52a, 52b can be a dedicated vessel or a collector / decanter. A coalescer 50a, 50b can be positioned downstream to the primary separator 52a, 52b to reach targeted electrolyte purity. The coalescer 50a, 50b can be of any type of coalescer. An example is a membrane type, but ultrasonic and centrifugal, among others, are also possible.

[0141] Horizontal primary separator vessels can be used. Alternatively or additionally, vertical primary separator vessels can be used to offer wider liquid differential height, and a wider allowable pressure deviation from nominal operation. This can accommodate the potential additional pressure drop in the circuit caused by the coalescer 50a, 50b. This piece of equipment may slowly be obstructed by impurities, such as potentially asymmetrically, causing differential pressure drop, which can naturally result in variation of liquid level in the vessel. In addition, vertical primary separator vessels will require a lower volume of liquid to move from a vessel to another for balancing the same overpressure on one side.

[0142] The hydrogen production system 100 may be referred to as a hydrogen production facility 100 in some examples, and so the terms may be used interchangeably.

[0143] The hydrogen production facility 100 includes at least one lye circulation system 22 coupled with the plurality of electrolysis systems 44 to circulate lye among the systems 44 to facilitate electrolysis. The system or facility may comprise a plurality of lyecirculation systems 22. In some arrangements, the lye circulation system 22 includes a lye circuit 56 for circulating lye to and from the plurality of electrolysis systems 44, for example as shown in Figure 7. In Figure 7, the lye circuit 56 includes a plurality of lines arranged to transfer lye from the electrolysis systems 44 to the separators (hydrogen separator 52a, oxygen separator 52b and respective coalescers 50a, 50b), and from the separators back to the electrolysis systems 44. The lye circuit 56 may include the pressure balancing line 54. The system or facility may comprise a plurality of lye circuits 56.

[0144] The lye circulation system 22 may include a purification line 58 that contains a purification system 60. The purification line 58 is in fluid communication with the lye circuit 56 such that a portion of lye is diverted from the lye circuit 56 to the purification system 60 and subsequently re-introduced into the lye circuit 56 at a point downstream of the purification system 60. The system or facility may comprise a plurality of lye purification systems 56. The lye circulation system 22 may be configured such that no more than 10 vol%, optionally no more than 5 vol%, optionally no more than 2 vol% of lye in the lye circulation system 22 is diverted from the lye circuit 56 to the purification line 58.

[0145] In some arrangements, lye is diverted from the lye circuit 56 to the purification line 58 at a point after lye from the hydrogen separators 52a, 50a and the oxygen separators 52b, 50b has been combined, for example as is shown in Figure 7. The lye may be re-introduced into the lye circuit 56 at any point downstream of the purification system 60. In the illustrated arrangement, lye is removed upstream of the pump 48 and is re-introduced downstream of the pump 48. It will be appreciated that lyemay be transferred between the purification line 58 and the lye circuit 56 at any point in the lye circuit 56. In some arrangements, lye may be transferred between the lye circuit 56 and the purification line 58 at a plurality of points in the lye circuit 56.

[0146] The lye circuit 56 may include one or more in-line filtration units 62 configured to remove solids from the lye in the lye circuit 56. In some arrangements, one or more in-line filtration units 62 may be provided in the lye circuit 56 upstream of lye from the hydrogen separators 52a, 50a being combined with lye from the oxygen separators 52b, 50b, for example as is shown in Figure 7. In this case, at least one in-line filtration unit 62 is provided on each side of the hydrogen production facility 100, for example at least one unit 62 on the hydrogen side and at least one unit 62 on the oxygen side. Additionally or alternatively, one or more in-line filtration units 62 may be provided downstream of the point at which lye from the hydrogen side is combined with lye from the oxygen side. The arrangement of in-line filtration units 62 may remove between 70 to 80% of solids (for example by wt%) present in the lye. The purification system 60 may be configured to remove substantially all of the remaining solids present in the lye in the purification line 58.

[0147] The in-line filtration units 62 may be omitted in some cases, such that the lye purification occurs solely in the purification line 58. The arrangement of in-line filtration units 62 may be provided as an alternative to the purification line 58 and purification system 60, in which case the purification line 58 and the purification system 60 may be omitted. In some arrangements, the in-line filtration units 62 may be provided in addition to the purification line 58 and purification system 60. In such an arrangement, the in-line filtration units 62 may provide a coarse removal of contaminants, such as solids, from thelye that circulates around the hydrogen production facility 100, while the purification system 60 may provide a more refined purification of a portion of the lye, generally reducing the presence of impurities or contaminants in the lye circulation system 22 to a desired or acceptable value.

[0148] Figure 8 shows an example arrangement of a portion of the lye circulation system 22 having the purification line 58 and purification system 60. The purification line 58 and purification system 60 may be implemented in addition to or as an alternative to one or more in-line filtration units 62. The purification system 60 may be configured to remove at least solid particles in the lye, and in some cases, to remove gas present in the lye, for example gas that may have been entrained in the lye during electrolysis. In some cases, solid particles may be suspended and / or dissolved in the lye. The presence of solid particles in the lye may lead to degradation of the performance of the electrolysis systems 44 in the hydrogen production facility 100, reducing their efficiency and therefore the efficiency of the production facility 100. As such, the provision of the purification system 60 can increase the efficiency of the production facility 100, and may reduce maintenance requirements.

[0149] The purification system 60 may include a first purification unit 64. The first purification unit 64 may be configured to remove gases and / or solids from the lye in the purification line 58. The first purification unit 64 may be or include one or more of a settling tank, a gravity separator or the like. In some arrangements, the first purification unit 64 may be or include a coalescer.

[0150] The purification system 60 may include a second purification unit 66. The second purification unit 66 may be configured to remove solids from the lye in thepurification line 58. The second purification unit 66 may be arranged to provide finer purification of the lye than the first purification unit 64. The second purification unit 66 may be configured to remove dissolved solids, elemental materials, metals or other contaminants that have a negative impact on the performance the facility from the lye.

[0151] The second purification unit 66 may be or include a purification unit. The purification unit may comprise a purification filter bed 67. The filter bed 67 may comprise one or more of: filter, resin, ferrite, apatite or any suitable material for removing contaminants such as solids or dissolved materials from the lye.

[0152] The second purification unit 66 may comprise a membrane separator 68. The second purification unit 66 may be provided downstream of the first purification unit 64, as shown in the illustrated arrangement. The first purification unit 64 may be provided downstream of the second purification unit 66 in alternative arrangements. In some arrangements, the first and second purification units 64, 66 may be integrated into a single unit. In some cases, one of the first and second purification units may be omitted. In some arrangements, additional purification units may be provided for further refining the lye. The purification system 60 may include a first pump 68 between the first purification unit 64 and the second purification unit 66 to transfer lye therebetween. The first pump may located anywhere along the purification line.

[0153] In some arrangements, the purification system 60 may operate at different conditions to the rest of the hydrogen production facility 100. For example, the purification system 60 may be located at a different, remote location, from the rest of the production facility 100. In some cases, the purification system 60 may operate at a lower pressure and / or a lower temperature. The purification system 60 may operate at generally ambientconditions. In this way, lye in the lye circuit 56 may be at a different, for example higher, pressure and / or temperature than lye in the purification system 60. A valve 70 may be provided in the purification line 58 upstream of the purification system 60 to reduce the lye pressure in the purification line. A heat exchanger such as a cooler 72 may be provided in the purification line 58 upstream of the purification system 60 to reduce the lye temperature in the purification line. The cooler 72 may be upstream or downstream of the valve 70 in arrangements in which both are provided. A second pump 74 may be provided in the purification line 58 downstream of the purification system 60 to increase the lye pressure prior to re-introducing the lye to the lye circuit 56. The second pump 74 may be configured to increase the lye pressure so as to be the same as or closer to an operating pressure of lye circuit. A heater 76 may be provided in the purification line 58 downstream of the purification system 60 to increase the lye temperature prior to re- introduction of the lye in the lye circuit 56. The heater 76 may be configured to increase the lye temperature so as to be the same as or closer to an operating temperature of lye circuit 56. The heat exchanger or heater 76 may be upstream or downstream of the second pump 74. It will be appreciated that the positioning of the valve 70, cooler 72, second pump 74 and heater 76 may be different depending on the difference in operating conditions between the purification system 60 and the lye circuit 56. One or more of these components may be omitted in cases where one or more operating conditions are or are desired to be substantially the same in the purification line as in the lye circuit 56.

[0154] Any one, or some, or all, of the features of the purification system described may be, may be comprised in, may be combined with or may be an alternative to, any features of the described cleaning system, including storage tanks, which may be or maycomprise the first and / or second separation units described and which may comprise any features thereof.

[0155] An in-line filtration system such as in-line filtration units 62 can remove a majority of contaminants or impurities in lye in the main electrolyzer system. The purification system (which is out of the main lye circuit and so may be considered off-line) can help to further reduce levels of contaminants or impurities in the lye. In reinjecting the purified lye in the main lye system, overall lye purity circulating in the electrolyser systems can be controlled in a fine manner. This way of purifying only a diverted portion of the lye stream enables the maintenance of a desired lye purity and can avoid the implementation of costly and bulky equipment that may be necessary if the whole lye stream is purified. The described configuration can also help in reducing the overall energy consumption, in particular by helping to minimize pumping requirements.

[0156] Further, the purification unit(s) can remove dissolved impurities that may have accumulated within the lye. This feature can provide a significant and positive impact on the electrolyzer systems, which may be subject to accelerated rates of performance degradation if levels of dissolved impurities are too elevated.

[0157] Figure 9 shows an example of how one or more modular units can be comprised in a plant according to the disclosure using an illustrative example based upon Figure 5B described earlier. It will be apparent that the modular principle can also be applied to an electrolysis plant or to a subsection of an electrolysis plant. A plant or a subsystem of a plant may be assembled from one or more pre-assembled modular units. As described earlier, such modular units may be assembled off-site before being brought to site for assembly into a plant, or before assembly to constitute a subsection of a plant.For example, a plant may comprise two or more systems as illustrated in figure 9, which may be subsystems of the plant.

[0158] A system may therefore comprise one or more lye circulation blocks 91 , which may comprise at least one pump and which may further comprise one or more fluid conduits arranged to circulate lie through the pump and to other modular units to which it is connected.

[0159] The system may comprise one or more electrolyser blocks 92, which may be connected to one another and / or connected to the lye circulation block 91 by one or more interconnecting blocks 93. The interconnecting block or blocks may comprise one or more fluid conduits, such as pipes, configured to connect other functional blocks of the system together to enable fluid such as gas or liquids in the system to flow between functional blocks.

[0160] One example of an interconnecting block 94 may comprise mutualized fluid connections, to enable a plurality of electrolysis systems, which may be comprised in electrolyzer blocks 92, to be connected to a shared or mutualized separator, or separators 140, which may be comprised in a separation system block 95.

[0161] As will be understood, other modules and / or blocks as described earlier herein may be integrated into the plant or subsystem of a plant in the modular fashion described above to incorporate other functions, such as power conversion.

[0162] Suitable connection interfaces 96 as described herein may be provided to the various functional blocks with the necessary connection interfaces for interconnection of the functional blocks to one another.

[0163] The foregoing description of certain examples, including illustrated examples, has been presented only for the purpose of illustration and description and is not intended to be exhaustive or to limit the disclosure to the precise forms disclosed. Numerous modifications, adaptations, and uses thereof will be apparent to those skilled in the art without departing from the scope of the disclosure.

Claims

Claims1 . A hydrogen production facility comprising: a plurality of electrolysis systems to electrolyze water using lye; and a mutualized lye circulation system coupled with the plurality of electrolysis systems to circulate the lye among the plurality of electrolysis systems to facilitate electrolyzing the water, the lye circulation system comprising one or more pumps, wherein a number of the one or more pumps is less than a number of electrolysis systems of the plurality of electrolysis systems.

2. The hydrogen production facility of claim 1 , wherein the lye circulation system comprises: a set of lye circulation lines sized to convey the lye between the plurality of electrolysis systems and a pump in a closed loop; and a lye cleaning subsystem positionable along the lye circulation system to clean the lye, wherein the lye cleaning subsystem is arranged within the set of lye circulation lines to clean the lye while the lye is circulating within the lye circulation system.

3. The hydrogen production facility of claim 1 , wherein the lye circulation system comprises a set of lye circulation lines sized to convey the lye to the plurality of electrolysis systems, wherein the lye circulation system comprises one or more cleaning tanks couplable with the set of lye circulation lines, and wherein the one or more cleaning tanksare sized to receive and clean the lye in situ in response to conveying the lye from the set of lye circulation lines to the one or more cleaning tanks.

4. The hydrogen production facility of any of the preceding claims, wherein the lye circulation system comprises a lye circuit for circulating lye to and from the plurality of electrolysis systems, and a purification line comprising at least one lye purification system, wherein the purification line is in fluid communication with the lye circuit and is configured to divert a portion of lye from the lye circuit to the at least one lye purification system and to re-introduce lye into the lye circulation system after passing through the at least one purification system.

5. The hydrogen production facility of claim 4, wherein the purification system comprises a first separation unit configured to remove gases and / or solids from the lye in the purification line, the first separation unit optionally comprises one or more of: a gravity separator or a settling tank.

6. The hydrogen production facility of claim 4 or claim 5, wherein the purification system comprises a second separation unit configured to remove solids from the lye in the purification line; optionally, the second separation unit is downstream of the first separation unit.

7. The hydrogen production facility of claim 6, wherein the second separation unit comprises a purification unit and / or a membrane separator; wherein the second separation unit optionally comprises one or more of: a filter, resin, ferrite, apatite.

8. The hydrogen production facility of any of claims 4 to 7, wherein the purification line comprises one or more of: at least one heat exchanger, at least one pressure reduction valve, and at least one pump.

9. The hydrogen production facility of any of claims 4 to 8, wherein the lye circuit comprises one or more in-line filtration units configured to remove solids from the lye in the lye circuit.

10. The hydrogen production facility of any of claims 4 to 9, wherein the lye circulation system is configured such that no more than 10 vol%, optionally no more than 5 vol%, optionally no more than 2 vol% of lye in the lye circulation system is diverted to the purification line during operation.11 . The hydrogen production facility of any preceding claim, further comprising: a first structure having a first interior and a first roof; a set of one or more power conversion units, wherein the plurality of electrolysis systems are positioned within the first structure, and wherein the set of one or more power conversion units is positioned on the first structure and coupled with the plurality of electrolysis systems.

12. The hydrogen production facility of claim 11 , further comprising: a second structure having a second interior and a second roof, wherein the second structure is positioned offset from the first structure; and wherein the plurality of electrolysis systems are positioned within the first structure and the second structure, and wherein the set of power conversion units are positioned on the first structure and the second structure and coupled with the plurality of electrolysis systems.

13. The hydrogen production facility of claim 12, wherein: the plurality of electrolysis systems comprises a first subset of electrolysis systems and a second subset of electrolysis systems; the first subset of electrolysis systems is positioned in the first interior and the second subset of electrolysis systems is positioned in the second interior; the set of power conversion units comprises a first subset of power conversion units and a second subset of power conversion units; the first subset of power conversion units is positioned on the first roof and coupled with the first subset of electrolysis systems; and the second subset of power conversion units is positioned on the second roof and coupled with the second subset of electrolysis systems.

14. The hydrogen production facility of claim 13, wherein:the first subset of power conversion units comprises a first set of transformers having a first number of transformers and the second subset of power conversion units comprises a second set of transformers having a second number of transformers; the first subset of electrolysis systems comprises a third number of electrolysis systems and the second subset of electrolysis systems comprises a fourth number of electrolysis systems; and the first number of transformers is less than the third number of electrolysis systems, and wherein the second number of transformers is optionally less than the fourth number of electrolysis systems.

15. The hydrogen production facility of any of the preceding claims, wherein the plurality of electrolysis systems are comprised in a modular structure, wherein the plurality of electrolysis systems are installed in the modular structure, such that the modular structure comprising the set of power conversion units, can be provided to and installed in the hydrogen production facility.

16. The hydrogen production facility of claim 15, wherein the plurality of electrolysis systems are comprised in a modular structure that further comprises one or more of: a set of power conversion units and a set of separators; wherein the plurality of electrolysis systems, the at least one of the set of power conversion units, and the set of separators are installed in one or more modules of the modular structure, such that the modular structure comprising at least one of the pluralityof electrolysis systems, the set of power conversion units, and the set of separators, can be provided to and installed in the hydrogen production facility.

17. The hydrogen production facility of claim 15, wherein the plurality of electrolysis systems are comprised in a modular structure that further comprises: a set of power conversion units; and a set of separators, wherein the plurality of electrolysis systems, the set of power conversion units, and the set of separators are installed in one or more modules of the modular structure, such that the modular structure comprising the plurality of electrolysis systems, the set of power conversion units, and the set of separators, can be provided to and installed in the hydrogen production facility.

18. The hydrogen production facility of any of claims 15 to 17, further comprising a second modular structure that is different than the modular structure, the second modular structure comprising: a second plurality of electrolysis systems that is different than the plurality of electrolysis systems; a second set of power conversion units that is different than the set of power conversion units; and a second set of separators that is different than the set of separators, wherein the second plurality of electrolysis systems, the second set of power conversion units, and the second set of separators are installed in one or more modules of the second modular structure, such that the modular structure comprising the second plurality of electrolysissystems, the second set of power conversion units, and the second set of separators, can be provided to and installed in the hydrogen production facility.

19. The hydrogen production facility of any of claims 15 to 18, wherein: the modular structure comprises a first housing that comprises a first set of walls; the plurality of electrolysis systems has a first distance measured between a first end of each electrolysis system of the plurality of electrolysis systems and at least one wall of the first set of walls; and the plurality of electrolysis systems has a second distance measured between a second end of each electrolysis system of the plurality of electrolysis systems and a third end of an adjacent electrolysis system of the plurality of electrolysis systems.

20. The hydrogen production facility of any of claims 15 to 19, wherein: the second modular structure comprises a second housing that comprises a second set of walls; the second plurality of electrolysis systems has a third distance measured between a first end of each electrolysis system of the second plurality of electrolysis systems and at least one wall of the second set of walls; the second plurality of electrolysis systems has a fourth distance measured between a second end of each electrolysis system of the second plurality of electrolysis systems and a third end of an adjacent electrolysis system of the second plurality of electrolysis systems; andthe first distance is the same as the third distance and the second distance is the same as the fourth distance.