Apparatus and process for electrolyte solution purification for hydrogen production via electrolysis
Patent Information
- Application Number
- AE202602335
- Authority / Receiving Office
- AE · AE
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2024-07-09
- Filing Date
- 2024-09-24
Smart Images
Figure ABST_ABST
Abstract
Description
APPARATUS AND PROCESS FOR ELECTROLYTE SOLUTION PURIFICATION FOR HYDROGEN PRODUCTION VIA ELECTROLYSIS CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority to U.S. Provisional Application No. 63 / 669,000 filed July 9, 2024 and U.S. Non-Provisional Application No. 18 / 409,971 filed on January 11, 2024. The entirety of both applications is incorporated herein by reference. FIELD OF THE INVENTION
[0002] The present innovation relates to processes and apparatuses for purification of electrolyte fluid for use in the production of hydrogen via electrolysis. BACKGROUND OF THE INVENTION
[0003] Hydrogen can be produced via electrolysis of water. Examples of systems configured to help facilitate the production of hydrogen via electrolysis are disclosed in U.S. Patent No. 11,929,613, and U.S. Patent Application Publication Nos. 2022 / 0033983 and 2024 / 0141524. SUMMARY OF THE INVENTION
[0004] Alkaline electrolyzers producing hydrogen via electrolysis can rely on concentrated aqueous hydroxide solutions as the conducting electrolyte. We have determined that maximum electrolyzer cell performance can depend on maintaining high conductivity in the electrolyte, through the separator and at the electrode electrolyte interfaces of the electrolyzer cell. Trace impurities including transition metal and organic impurities can lead to resistance increases at the electrode interfaces and within the electrolyte, which can reduce the performance of the electrolyzer cell.
[0005] In contrast to proton exchange membrane water electrolysis (PEMWE), alkaline water electrolysis (AWE) producing hydrogen relies on concentrated hydroxide solutions as the conducting electrolyte. Hydroxide ion conductivities may be achieved with aqueous potassium hydroxide (KOH) solution at ~30 weight percent (wt%) in concentration, though other concentration ranges can alternatively be used for alkaline water electrolysis (AWE) (e.g. 0.5 wt% KOH to 50 wt% KOH, between 15 wt% KOH to 25 wt% KOH, between 25 wt% KOH to 35 wt% KOH). We have found that common impurities in KOH and water increase electrolyzer cell resistance in a number of ways. For example, reducible transition metal impurities can plate out on electrode and electrocatalyst surfaces changing and in many cases increasing cell overpotential. Indeed, we have found that long-term, stable operation of electrolyzer cells can be provided when iron (II) cations (Fe2+) and iron (III) cations (Fe3+) are kept at very low levels. Examples of such a low level of iron within an electrolyte solution can be an iron content threshold of between 0 parts per billion (ppb) iron and 400 ppb iron, between 0 ppb iron and 200 ppb iron, between 100 ppb iron and 0 ppb iron or between 50 ppm iron and 0 ppb iron. For example, some embodiments may utilize an iron content threshold of no more than 100 ppb iron or no more than 50 ppb iron for electrolyte solution for use in AWE electrolyzers.
[0006] We have found that use of a pre-selected iron concentration threshold can help ensure purified electrolyte solution can be formed and fed to electrolyzer cells to help preserve electrolyzer life and avoid fouling of electrodes, or at the very least help greatly minimize such corrosion or fouling. And we have surprisingly found that this type of issue can be substantial for industrial applications that may utilize a large number of electrolyzer units for large scale production of hydrogen via electrolysis.
[0007] For example, for giga Watt (GW) scale electrolysis units, the buildup of impurities in the electrolyte can be substantial and could necessitate the replacement of thousands of metric tons (MT) of caustic electrolyte. This can represent an enormous materials cost and logistical challenge. For instance, disposal of so much KOH solution can have significant environmental impact, and the cost of replacing that solution in terms of material costs as well as operational downtime for the replacement can be substantial as well as reduce production flexibility.
[0008] We have found that purification of the electrolyte solution can reduce the levels of some or all significant impurities to help delay or avoid fouling to preserve the working life of the electrolyte solution. This can help reduce operational downtime and costs associated with electrolyte solution replacement as well as refurbishment or replacement of electrodes. We have found that a suitable purification of the electrolyte solution at the outset of its supply and use can help prevent early damage to electrolysis cells and preserve the life of those units. We have surprisingly found that focusing on a pre-selected iron concentration threshold to help control for purification can help ensure suitable purification to preserve electrolyzer life and help limit or avoid electrode fouling and / or corrosion.
[0009] For example, purification that results in a reduction of iron within the electrolyte solution can also facilitate removal of other transition metals, inorganic anions such as sulfate and carbonate etc.; and organic impurities such as phthalate esters and their alkali phthalate hydrolysis products, phenolic components, and trace humic acid type organic material. Other impurities are also removed and the iron concentration threshold that is selected can help facilitate a removal of these other impurities as well as iron being significant while also ensuring iron impurity content within the electrolyte solution is at or below a threshold value (e.g. 500 ppb, 200 ppb, 100 ppb, 50 ppb, etc.)
[0010] While the focus on removal of iron from the electrolyte solution for purification of that solution can facilitate a removal of carbonate and / or sulfate impurities, we have found that the reduction in the amount of dissolved iron can help ensure that organic compounds are removed as well. It is contemplated that organic compound impurities can also be reduced to acceptable levels in the electrolyte solutions that are formed as hydroxide solutions (e.g. KOH electrolyte solutions, etc.) in some embodiments.
[0011] Embodiments can be adapted to help provide a process for purification of electrolyte solution that can be performed relatively quickly. Also, some embodiments can be provided as a mobile purification system so that the purification system can be removably coupled to different production units for use in different electrolyte purification processes that may support multiple different industrial processing locations at different spaced apart geographic regions (e.g. at different facilities located in different states or countries, etc.). Other embodiments can alternatively be provided as a site-specific system for purification of electrolyte solution.
[0012] In a first aspect, a process for electrolyte purification can be provided. Embodiments of the process can include purifying electrolyte solution so that an iron (Fe) content of the electrolyte solution is at or below a pre-selected Fe concentration threshold. The pre-selected Fe concentration threshold can be between 0 parts per billion (ppb) Fe and 500 ppb Fe in some embodiments. The purifying of the electrolyte solution can include passing the electrolyte solution through a reactor to contact purification material within a chamber of the reactor for removal of impurities and / or filtering the electrolyte solution to remove impurities from the electrolyte solution. The process can also include feeding the purified electrolyte solution to a storage tank or to one or more electrolyzers.
[0013] In some embodiments, the pre-selected Fe concentration threshold can be between 0 ppb F3 and 200 ppb Fe or between 100 ppb and 200 ppb Fe. In other embodiments, the pre-selected Fe concentration can be another pre-selected threshold (e.g. no more than 50 ppb Fe, no more than 150 ppb Fe, etc.).
[0014] In a second aspect, the purifying of the electrolyte solution can include passing the electrolyte solution through the reactor to contact the purification material within the chamber of the reactor for removal of impurities. The purification material within the chamber of the reactor can include at least one impurity removing agent. In some embodiments, the at least one impurity removing agent can be coated on a support of a particulate. In other embodiments, the purification material can include solid particulates that include at least one impurity removing agent. In some embodiments, the impurity removing agent can include magnesium oxide (MgO) and / or magnesium hydroxide ((Mg(OH)2).
[0015] In a third aspect, the purifying of the electrolyte solution can also include the filtering of the electrolyte solution to remove impurities from the electrolyte solution. The filtering can be performed instead of passing the electrolyte solution through the reactor or can be performed in addition to the passing of the electrolyte solution through the reactor. In some embodiments, filtering can be performed via at least one filter element or filter mechanism positioned in the reactor near an outlet of the reactor that is in fluid communication with the chamber of the reactor, for example.
[0016] In a fourth aspect, the process can include other steps. For example, the process can include forming the electrolyte solution by mixing electrolyte material with water and at least one purification material within a mixing tank. In some embodiments, the purifying of the electrolyte solution can include the filtering of the electrolyte solution to remove the purification material from the electrolyte solution to remove impurities from the electrolyte solution after the electrolyte material is mixed with the water. For example, in some embodiments the process can include feeding the electrolyte solution from the mixing tank to at least one filtration system for the filtering of the electrolyte solution to remove the purification material from the electrolyte solution to remove impurities from the electrolyte solution. The electrolyte solution that was purified via the at least one filtration system can subsequently be fed to a storage tank that can be fluidly connected to at least one electrolyzer.
[0017] In a fifth aspect, the process can include feeding the electrolyte solution that was purified via the purifying of the electrolyte solution to the storage tank. The storage tank can be fluidly connected to at least one electrolyzer. Then the electrolyte solution can be fed to the electrolyzer(s) via the storage tank. Alternatively, the electrolyte solution can be fed to the electrolyzer(s) without intermediate storage within such a storage tank.
[0018] In a sixth aspect, the process can be utilized in conjunction with a purification system that can be configured as a mobile purification system. For example, the process can include decoupling a mobile purification system that performed the purifying of the electrolyzer solution from the storage tank after the feeding of the purified electrolyte solution to the storage tank and moving the mobile purification system to another site for purification of electrolyte solution at the site or moving the mobile purification system to another storage tank for purification of electrolyte solution stored therein. The mobile purification unit can include a mobile reactor and / or mobile filtration system in some embodiments.
[0019] In a seventh aspect, the process of the first aspect can include one or more features of the second aspect, third aspect, fourth aspect, fifth aspect, and / or sixth aspect. Embodiments of the process can also include other process steps or elements. Examples of such other features or process steps can be appreciated from the discussion of exemplary embodiments of the process discussed herein.
[0020] Embodiments of the process can be implemented in an exemplary embodiment of an apparatus for purification of electrolyte solution. Such an apparatus can include conduits, valves, and / or a process control system to facilitate operation of the apparatus and / or implementation of an embodiment of the process.
[0021] In an eighth aspect, an apparatus for purification of electrolyte solution is provided. The apparatus can include a reactor having a chamber that retains purification material within the chamber. The purification material can be configured to remove impurities from electrolyte solution to reduce an iron (Fe) content of the electrolyte solution to form a purified electrolyte solution having an Fe content that is at or below a pre-selected Fe content threshold of between 0 parts per billion (ppb) Fe and 500 ppb Fe.
[0022] The apparatus can also include a reactor inlet conduit connected to an inlet of the reactor. The reactor inlet conduit can be connectable to a source of the electrolyte solution or a storage tank in which the electrolyte solution is retainable.
[0023] The apparatus can also include a reactor outlet conduit connected to an outlet of the reactor. The reactor outlet conduit can be connectable to a storage tank and / or an electrolyzer feed conduit to feed purified electrolyte solution outputtable from the reactor to the storage tank and / or at least one electrolyzer.
[0024] In some embodiments, the purification material includes magnesium oxide (MgO) and / or magnesium hydroxide ((Mg(OH)2). For instance, in some embodiments, the purification material can include MgO and / or Mg(OH)2 as a coating on a support and / or in solid particulates that can be positioned in the chamber of the reactor for contact with the electrolyte solution for removal of Fe and other impurities of the electrolyte solution.
[0025] In other embodiments, the purification material can include other types of impurity removing agents that can remove Fe and / or other impurities.
[0026] Embodiments of the apparatus can be configured to implement an embodiment of the process for purifying electrolyte solution.
[0027] In a ninth aspect, the apparatus also includes a pump connected to the reactor inlet conduit and a mobile base that supports the pump, the reactor inlet conduit, the reactor outlet conduit, and the reactor. In some embodiments, the mobile base can be a mobile skid, a mobile trailer, or other type of mobile support that may be moveable via railcar, truck, forklift, or other type of vehicle.
[0028] In a tenth aspect, the apparatus can include the storage tank. An output conduit of the storage tank can be connectable to a pump to feed electrolyte solution within the storage tank to the reactor inlet conduit.
[0029] In an eleventh aspect, the apparatus can include the electrolyzer feed conduit. The electrolyzer feed conduit can be connected to the reactor outlet conduit to fluidly connect the reactor to the at least one electrolyzer to feed the purified electrolyte solution outputtable from the reactor to the at least one electrolyzer.
[0030] In a twelfth aspect, the apparatus of the eighth aspect can include one or more features of the ninth aspect, tenth aspect, and / or eleventh aspect. Embodiments can also include other features or elements. Examples of such features or elements can be appreciated from the discussion of exemplary embodiments of the apparatus provided herein, for instance.
[0031] In a thirteenth aspect, an apparatus for purification of electrolyte solution can include a mixing tank fluidly connected to a source of water, a source of electrolyte material, and a source of purification material to receive the water, the electrolyte material, and the purification material for mixing therein to form electrolyte solution. A filtration system can be connected to the mixing tank to receive the electrolyte solution from the mixing tank and remove particulates of the purification material from the electrolyte solution to output a purified electrolyte solution having an iron content that is less than or equal to a pre-selected iron (Fe) content threshold, the pre-selected Fe content threshold being between 0 parts per billion (ppb) Fe and 500 ppb Fe. Embodiments of the apparatus can be configured to implement an embodiment of the process for purifying electrolyte solution.
[0032] Embodiments of the apparatus can also include other features or elements. For example, the apparatus can also include a storage tank positioned downstream of the filtration system to receive the purified electrolyte solution output from the filtration system and / or at least one electrolyzer fluidly connected to the storage tank to receive the purified electrolyte solution from the storage tank.
[0033] As noted above, in some embodiments the purification material includes magnesium oxide (MgO) and / or magnesium hydroxide ((Mg(OH)2). For instance, in some embodiments, the purification material can include MgO and / or Mg(OH)2 as a coating on a support and / or in solid particulates that can be positioned in the mixing tank for contact with the other components of the electrolyte solution that is to be formed for removal of Fe and other impurities of the electrolyte solution via subsequent filtration of the purification material from the formed electrolyte solution. In other embodiments, the purification material can include other types of impurity removing agents that can remove Fe and / or other impurities.
[0034] It should be appreciated that embodiments of the process and apparatus can utilize various conduit arrangements and process control elements. The embodiments may utilize sensors (e.g., pressure sensors, temperature sensors, flow rate sensors, concentration sensors, etc.), controllers, valves, piping, and other process control elements. Some embodiments can utilize an automated process control system and / or a distributed control system (DCS), for example. Various different conduit arrangements and process control systems can be utilized to meet a particular set of design criteria.
[0035] Other details, objects, and advantages of the apparatus for electrolyte solution purification, process for electrolyte solution purification, system for providing electrolyte solution for hydrogen production via electrolysis, and methods of making and using the same will become apparent as the following description of certain exemplary embodiments thereof proceeds. BRIEF DESCRIPTION OF THE DRAWINGS
[0036] Exemplary embodiments of our apparatus for electrolyte solution purification, a process for electrolyte purification, system for providing electrolyte solution for hydrogen production via electrolysis and methods of making and using the same are shown in the drawings included herewith. It should be understood that like reference characters used in the drawings may identify like components.
[0037] Figure 1 is a block diagram of a first exemplary embodiment of an apparatus for electrolyte solution purification.An exemplary embodiment of a process for electrolyte solution purification is also illustrated in this Figure.
[0038] Figure 2 is a block diagram of a first exemplary implementation of the first exemplary embodiment of an apparatus for electrolyte solution purification. An exemplary embodiment of a process for electrolyte solution purification is also illustrated in this Figure.
[0039] Figure 3 is a block diagram of a second exemplary implementation of the first exemplary embodiment of an apparatus for electrolyte solution purification. An exemplary embodiment of a process for electrolyte solution purification is also illustrated in this Figure.
[0040] Figure 4 is a block diagram of a third exemplary implementation of the first exemplary embodiment of an apparatus for electrolyte solution purification. An exemplary embodiment of a process for electrolyte solution purification is also illustrated in this Figure.
[0041] Figure 5 is a block diagram of a fourth exemplary implementation of the first exemplary embodiment of an apparatus for electrolyte solution purification. An exemplary embodiment of a process for electrolyte solution purification is also illustrated in this Figure.
[0042] Figure 6 is a schematic illustration of a first exemplary embodiment of a reactor 5 that can be utilized in the embodiments of an apparatus for electrolyte solution purification shown in Figures 1-5.
[0043] Figure 7 is a schematic illustration of a second exemplary embodiment of a reactor 5 that can be utilized in the embodiments of an apparatus for electrolyte solution purification shown in Figures 1-5.
[0044] Figure 8 is a schematic illustration of an exemplary embodiment of purification material 5m that can be included in the exemplary embodiments of the reactor 5.
[0045] Figure 9 is a schematic illustration of another exemplary embodiment of purification material 5m that can be included in the exemplary embodiments of the reactor 5.
[0046] Figure 10 is a flow chart illustrating an exemplary embodiment of a process for electrolyte solution purification. Embodiments of the apparatus for electrolyte solution purification can implement this exemplary embodiment of the process. DETAILED DESCRIPTION OF THE INVENTION
[0047] Referring to Figures 1-10, an apparatus 1 for electrolyte solution purification can be provided to purify electrolyte solution so the purified electrolyte solution can be fed to one or more electrolyzers E and / or a storage tank 3 positioned for supplying electrolyte solution to at least one cell of one or more electrolyzers. The apparatus can include a purification unit 4 that can be positioned so that electrolyte solution from a source of electrolyte solution ES can be fed to the purification unit for purification of the electrolyte solution. The electrolyte solution can include a pre-selected concentration of electrolyte therein. For example, the electrolyte solution can have a pre-selected concentration of electrolyte material that is between 0.5 wt% electrolyte and 50 wt% electrolyte (e.g. 0.5 wt% KOH to 50 wt% KOH, between 15 wt% KOH to 25 wt% KOH between 25 wt% KOH to 35 wt% KOH, etc.). The purification unit 4 can be positioned to receive the electrolyte solution from a source of the electrolyte solution ES or from a storage tank 3 that can receive the electrolyte solution from the source of the electrolyte solution ES for retaining the fluid therein for subsequently providing it to one or more electrolyzers E.
[0048] The storage tank 3 can include a tank, an array of vessels, or other type of storage device for storing of electrolyte solution to feed that solution to one or more electrolyzers E. Each electrolyzer E can be an alkaline water electrolysis (AWE) electrolyzer or other suitable type of electrolyzer. The electrolyzers E can be powered via renewable power sources to produce green hydrogen via electrolysis of water. For example, a source of power that results in electricity being generated by a renewable source (e.g. solar power, wind power, hydroelectric power, etc.). In some embodiments, the apparatus 1 can be incorporated into a plant for production of hydrogen and / or a plant that can produce hydrogen for subsequent use in producing ammonia. For embodiments configured for utilization in an ammonia producing facility, there can also be an air separation unit positioned to form nitrogen gas so that the hydrogen from the electrolyzer(s) E and the nitrogen gas can be utilized to form ammonia.
[0049] The electrolyte solution source ES can be a supply of electrolyte solution that can include electrolyte solution stored in at least one vessel or tank provided by a supplier. The electrolyte solution source ES can alternatively include a mixing tank 13 that can form the electrolyte solution from water (e.g. highly purified water), potassium hydroxide (KOH), and / or other materials that are combined in the mixing tank for forming the electrolyte solution. The electrolyte solution source ES can also include a combination of such sources. The electrolyte solution can include use of KOH as a main electrolytic component of the electrolyte solution. Other embodiments can utilize other types of hydroxide salts or other types of electrolysis electrolyte compounds for use in forming the electrolyte solution.
[0050] The purification unit 4 can include a reactor 5 that can be configured to include a purification material 5m for contacting the electrolyte solution and interacting with the fluid of the electrolyte solution to remove impurities from the electrolyte solution to purify the solution. The purification material 5m can be an impurity removing agent, a reagent material, an adsorbent material, an absorbent material, or other type of purification material 5m.
[0051] For example, in some embodiments, the purification material 5m that can be positioned in the chamber 5c of the reactor for contacting the electrolyte solution to purify it can include magnesium oxide (e.g. MgO) and / or magnesium hydroxide (e.g. Mg(OH)2). The purification material 5m can be a coating that is on a support, can be in particulate form 5p (e.g. a pellet form of a particular size, etc.), or can be provided in small particulate form for being provided as a compressed particulate cake 5cake in different embodiments. The particulate sizing for the purification material can be between 0.2 and 3 micrometers in size for being provided in a cake 5cake in some embodiments. The particulate size of the purification material 5m that can be utilized as the impurity removing material within the chamber 5c of the reactor can be between 0.1 millimeters (mm) and 3 mm in size in some embodiments. The sizing, shape, and structure of the particulate purification material 5m can include voids, be solid shaped structures, or be other shapes or geometries to facilitate a desired level of contact and residence time with the electrolyte solution passed through the chamber 5c of the reactor 5 for contact with the purification material 5 for removal of impurities (e.g. Fe) and purification of the electrolyte solution.
[0052] The purification unit 4 can alternatively include at least one filtration device of a filtration system FS that can filter out impurity containing precipitates that may have formed in the electrolyte solution and / or other solid particulates within the electrolyte solution that may be, include, or have impurities to purify the electrolyte solution. Some embodiments can also utilize a purification unit 4 that includes a combination of at least one filtration system FS and at least one reactor 5 for purification of the electrolyte solution.
[0053] Embodiments can be provided so that the electrolyte solution passed through the purification unit 4 can have a residence time within the reactor 5 that is no more than 30 minutes, no more than 1 hour, or within another pre-selected purification time range (e.g. a time range of greater than 0 seconds and less than or equal to 2 hours, a time range of greater than 0 seconds and less than or equal to 1 hour, or a time range of greater than 0 seconds and less than or equal to 30 minutes, a time range of greater than 0 seconds and less than or equal to 5 minutes, a time range of greater than 0 seconds and less than or equal to 30 seconds, etc.). For example, electrolyte solution can be fed to the reactor 5 via a reactor feed conduit 5i. The feed electrolyte solution can include impurities that are above a pre-selected impurity criteria. For instance, the electrolyte solution fed to the reactor for being purified can have over 500 ppb iron, at least 600 ppb iron, over 800 ppb iron, over 1,000 ppb iron, or other high impurity concentrations.
[0054] The reactor 5 can purify the electrolyte solution so that the purified electrolyte solution can be output from the reactor 5 as a purified electrolyte solution output stream that can be passed through a reactor output conduit 5o to at least one electrolyzer E or the storage tank 3. The purified electrolyte solution can have an impurity content that is within a pre-selected impurity content threshold range or pre-selected impurity content criteria. Such a criteria or content threshold range can include, for example, a pre-selected iron content that is at or below a pre-selected iron content threshold. A pre-selected iron content threshold can be, for example, between 0 ppb iron (Fe) and 50 ppb Fe, between 0 ppb Fe and 100 ppb Fe, between 0 ppb iron Fe and 200 ppb Fe, between 0 ppb Fe and 400 ppb Fe, between 0 ppb Fe and 500 ppb Fe, or other desired range. The utilization of a pre-selected iron content threshold has been found to also provide a proxy for providing a desirable low level of other impurities such as transition metal impurities and organic impurities (e.g. phthalate esters and their alkali phthalate hydrolysis products, phenolic components, trace humic acid type organic material, etc.). The purification of the electrolyte solution can result in impurities within the electrolyte solution having a lower content within the electrolyte solution that is output from the reactor 5 (e.g. the electrolyte solution fed to the reactor can have a higher impurity content than the impurity content of the purified electrolyte solution output from the reactor 5).
[0055] In some embodiments, at least a portion of the purified electrolyte solution can be output from the reactor 5 as a purified electrolyte solution output stream can be recycled back to the reactor 5 for further purification via a recycle conduit R. The recycling of the electrolyte solution back to the reactor 5 can be provided to help ensure that the electrolyte solution being purified has sufficient residence time for providing a desired purification level of the electrolyte solution that is ultimately output from the reactor 5 for use by one or more electrolyzers.
[0056] In some embodiments, the purification unit 4 can be mobile and modular for removable fluid connection with a source of electrolyte solution ES or a storage tank 3. When coupled to such an element or such elements, the purification unit can receive electrolyte solution for purification of that solution. After purification has been performed and electrolyte solution has been purified for feeding to electrolyzers at a particular geographical location, the mobile purification unit 4 can be decoupled from the element(s) at that location and moved to a new geographic location that is remote from the location at which it was previously utilized. Once at the new location, the purification unit can be removably connected with a source of electrolyte solution ES or a storage tank 3 at the new location for purification of electrolyte solution at that new location.
[0057] In yet other situations, after use in connection with a first storage tank 3 at a particular site, the mobile purification unit 4 can be decoupled from the element(s) at that initial storage tank 3 and moved to a second storage tank 3 at the same site for subsequent use at that site. After an entire site’s storage tanks have had their electrolyte solution purified, the mobile purification unit 4 can subsequently be moved to a new geographical location to another plant at another site for subsequent utilization at the new site.
[0058] Often, electrolyte solution purification may only be needed once every 2-3 years or intermittently at any one particular location. In other situations, electrolyte solution may only need to be purified at an initial time before it is fed to an electrolyzer and may not subsequently need to undergo any further processing as the solution is utilized during operations of the electrolyzer. A mobile purification unit 4 can provide improved flexibility by permitting a single asset to be moved to different locations (or different sources or storage tanks) for use at different times so that the capital cost associated with that asset can be more efficiently and flexibility allocated to supporting numerous different remote production facilities. In some embodiments, the mobile purification unit can be positioned on a trailer or skid so that the purification unit can be transported via truck, railcar and / or other vehicle for being removably connected to different units at different locations. Removable fluid connections can be provided via valves, mechanical fasteners, or other removable connection mechanisms for removably connecting reactor inlet and reactor outlet conduits to a storage tank 3, electrolyzer feed conduit, or other conduit arrangement so that the purification unit 4 can receive the electrolyte fluid, purify it, and subsequently output the purified fluid to at least one storage tank 3 and / or at least one electrolyzer E. In some embodiments, for example, the purified electrolyte solution that is output can be fed to a different storage tank for storage of the purified solution that can be fluidly connectable to the electrolyzer(s) E.
[0059] Also, embodiments can be utilized to purify spent electrolyte solution as well as fresh electrolyte solution. For example, embodiments can be configured so that during an electrolyzer shutdown, spent solution can be drained into a storage tank and subsequently purified via the purification unit 4 before it is fed back to the electrolyzer(s) or storage tank for being subsequently fed back to the electrolyzer(s). In some embodiments, the purification unit can be coupled one or more drain lines between the electrolyzer(s) and storage tank(s) for such processing.
[0060] Figures 2- 5 illustrate different exemplary implementations for the exemplary embodiment of the apparatus 1 illustrated in Figure 1 to illustrate different types of arrangements that may be utilized in the exemplary embodiment of the apparatus 1 shown in Figure 1.
[0061] Referring to Figure 2, electrolyte solution stored in a storage tank 3 can be output from the tank 3 via an output conduit 3o for feeding to a pump P. The stored electrolyte solution can be fresh solution or may be spent solution drained from at least one electrolyzer E. The pump can output the electrolyte solution as a higher pressure electrolyte solution stream 7 for being fed to a reactor feed conduit 5i connected between the storage tank 3 and the reactor 5 and / or for being fed to electrolyzer(s) E via an electrolyzer feed conduit 9 that can be connected between the storage tank 3 and the electrolyzer(s) E to feed the electrolyte solution to a reactor 5 for purification of the electrolyte solution. The reactor feed conduit 5i can include a valve V that can be adjustable between an open position and a closed position. In a closed position, fluid may not pass to the reactor. In an open position, at least some of the electrolyte solution can be passed to the reactor 5 via the reactor feed conduit 5i.
[0062] For example, the electrolyzer feed conduit 9 can include a first valve V1 that is upstream of the fourth valve V4 and a second valve V2. A storage tank inlet conduit 3i can also be connected between the pump P and the storage tank so that in the event the first and fourth valves V1 and V4 or the second and fourth valves V2 and V4 are closed, the electrolyte solution can be returned to the storage tank 3. The storage tank inlet conduit can include a third valve V3 that can be adjustable between open and closed positions to facilitate such a flow of electrolyte solution (e.g. the third valve V3 can be closed when electrolyte solution is fed to the electrolyzers E and / or reactor 5 and can be opened to permit electrolyte solution to be returned to the storage tank 3 in the event the feeding of solution to the electrolyzers E and / or reactor 5 is stopped.
[0063] In some embodiments, the second valve V2 can be a check valve. In other embodiments, the second valve V2 can be another type of valve.
[0064] The reactor 5 can receive electrolyte solution via the reactor feed conduit 5i when the fourth valve V4 is in an open position or a partially open position. Purification material 5m within the chamber 5c of the reactor can contact the electrolyte solution passed through the reactor 5 as the electrolyte solution flows through the reactor 5 to an outlet of the reactor 5 that is in fluid communication with the reactor output conduit 5o as indicated by arrow ESF shown in Figures 6 and 7. The purified electrolyte solution output from the reactor 5 can be passed through the reactor output conduit 5o for being fed to the electrolyzer feed conduit 9 for being fed to the electrolyzer(s) E. The reactor output conduit 5o can include a fifth valve V5 that can be in an open position to facilitate the feeding of the purified solution to the electrolyzer(s) E.
[0065] In some embodiments, the fifth valve V5 can be closed during purification so that the electrolyte solution passed through the reactor 5 and output from the reactor can be recycled back to the reactor 5 via a recycle conduit arrangement R positioned between the reactor output conduit 5o and the reactor 5. One the fluid is sufficiently purified, the fifth valve V5 can be opened so that the fluid output from the reactor 5 can be fed to the electrolyzer(s) E via the output conduit 5o. Alternatively, no such recycle conduit may be utilized or the fifth valve V5 can be opened for feeding some purified electrolyte solution to the electrolyzers while another portion of the output fluid is recycled back to the rector via the recycle conduit arrangement R.
[0066] The positions of the fourth and fifth valves V4, V5 as well as the first valve V1 can be adjusted to control an extent to which the electrolyte solution output from the storage tank 3 is fed to the electrolyzer(s) E. In some configurations, all the fluid may be fed to the reactor 5 and subsequently output from the reactor as purified electrolyte solution for feeding to the electrolyzer(s) E. In other situations, only some of the electrolyte solution may need to be purified to control for the impurity content of the solution so that the solution fed to the electrolyzers is at or below a pre-selected impurity content. In such a situation, only some electrolyte solution may be purified and the purified electrolyte solution output from the reactor can be mixed with less purified electrolyte solution passed through the electrolyzer feed conduit 9. An in-line mixer or other type of mixing unit can be positioned in the electrolyzer feed conduit 9 to facilitate the mixing of the purified electrolyte solution with the non-purified solution at a location at which the purified electrolyte solution output from the reactor 5 is passed into the electrolyzer feed conduit 9 or at a location that is downstream of the location at which the purified electrolyte solution output from the reactor 5 is passed into the electrolyzer feed conduit 9 via the output conduit 5o.
[0067] Referring to Figure 3, the purification unit 4 can alternatively be arranged to purify electrolyte solution stored in the storage tank 3 before it is then fed to the electrolyzer(s) E. The stored electrolyte solution can be fresh solution or may be spent solution drained from at least one electrolyzer E.
[0068] For example, the reactor feed conduit 5i can be connected to the storage tank inlet conduit 3i so that electrolyte solution output from the pump P can fed to the reactor 5 while the first valve V1 and / or second valve V2 are closed. The third valve V3 can also be in a closed position in the event the reactor feed conduit 5i is positioned upstream of the third valve V3 and the reactor output conduit 5o is positioned downstream of the third valve V3. This type of arrangement can permit electrolyte solution in the tank 3 to be passed through the rector 5 in one or more passes to purify the electrolyte solution via the pump P. After the electrolyte solution is sufficiently purified to be at or below a pre-selected iron content threshold, the fourth and fifth valves V4 and V5 can be closed and the electrolyte solution stored in the storage tank 3 can be available for feeding to the one or more electrolyzers E via the electrolyzer feed conduit 9.
[0069] In some configurations or implementation, the purification unit 4 can be arranged to purify some of the electrolyte solution stored in the storage tank 3 before it is then fed to the electrolyzer(s) E while another portion of the electrolyte solution stored in the storage tank is fed to the electrolyzer(s) without undergoing purification. Such an operation can be provided via partial opening of the first valve V1, second valve V2, and third valve V3. This type of configuration can permit purification of only a portion of the electrolyte solution that may be needed so that the electrolyte solution fed toward the electrolyzer(s) E is at or below a pre-selected impurity content threshold (e.g. an Fe content of no more than 200 ppb, an Fe content of no more than 100 ppb, an Fe content of no more than 500 ppb, etc.).
[0070] As indicated in broken line in Figure 3, the reactor 5, the reactor feed conduit 5i, and reactor output conduit 5o can be positioned on a mobile skid or other mobile base so that these elements are part of a mobile purification system MPS that can be releaseably connected to the storage tank inlet conduit 3i via the fourth and fifth valves V4 and V5, or other type of removable connection elements. After purification of the electrolyte solution has occurred, the mobile purification system MPS can be decoupled from the storage tank inlet conduit 3i for being moved to a new site for purification of other electrolyte solution stored in a different tank at the same facility as the first storage tank or at a different facility at a different geographic location.
[0071] Figure 4 illustrates another exemplary implementation in which the purification unit 4 is included in a mobile purification system MPS. In the exemplary embodiment of Figure 4, the storage tank output conduit 3o can be a drain conduit that can be fluidly connected to a pump P of the mobile purification system MPS via a valve V and / or other releasable connection mechanism positioned between a reactor feed conduit 5i of the mobile purification system MPS and the storage tank output conduit 3o.
[0072] The pump P of the mobile purification system can drive a flow of the electrolyte solution within the tank 3 to the reactor 5 for being purified therein via contact with purification material 5m. The purified electrolyte solution can be output from the rector and fed to a storage tank feed conduit 3f. A valve V and / or other releasable connection mechanism can be positioned between the reactor output conduit 5o of the mobile purification system MPS and the storage tank feed conduit 3f to facilitate the flow of the purified electrolyte solution from the reactor 5 to the storage tank 3. The storage tank feed conduit can include a valve V that can be in an open position to receive the purified electrolyte solution output from the reactor 5 for being stored in the storage tank.
[0073] The storage tank feed conduit 3f can also be connected to a source of electrolyte solution ES so that non-purified electrolyte solution from the source can be fed to the storage tank for being stored therein.
[0074] After the electrolyte solution is sufficiently purified via one or more passes through the reactor 5 of the mobile purification system MPS, the electrolyte solution stored in the tank 3 can be at or below a pre-selected impurity threshold (e.g. a pre-selected iron content threshold). The purified electrolyte solution within the storage tank 3 can then be output from the storage tank via an electrolyzer feed conduit 9 that is connected to the storage tank 3. An electrolyzer feed pump P or other pump P can be actuated to help drive the flow of the purified electrolyte solution from the storage tank 3 to the electrolyzer(s) E via the electrolyzer feed conduit 9.
[0075] After purification of the electrolyte solution has occurred, the mobile purification system MPS can be decoupled from the storage tank 3 for being moved to a new site or new location for purification of other electrolyte solution stored in a different tank. The different tank can be a different storage tank at the same facility or a different storage tank at a different facility located in a different geographic location. Such a decoupling can be facilitated by decoupling the pump P of the mobile purification system MPS from the storage tank output conduit 3o (e.g. drain conduit) and decoupling the storage tank feed conduit 3f from the reactor output conduit 5o via the valves V or other connection mechanism. The elements of the mobile purification system MPS (e.g. reactor 5, pump P, reactor output conduit 5o, reactor feed conduit 5i, etc.) can be positioned on a mobile base (e.g. a skid, a trailer, etc.) so that the mobile purification system can be moved to a new location after being decoupled. At the new location, the reactor output conduit 5o and pump P and / or reactor feed conduit 5i can be connected to a storage tank 3 for purification of the electrolyte solution stored in that new storage tank at that new location.
[0076] Referring to Figure 5, the purification unit 4 can include a filtration system FS that can include one or more filters for removal of impurity containing precipitates. A mixing tank 13 can be a source of electrolyte solution that can form the electrolyte solution via receipt of a feed of water from a source of water 21 (e.g. a source of highly purified water), and a feed of electrolyte material from at least one source of electrolyte material 23. The electrolyte material 23 can also include one or more impurity removing agents (e.g. MgO, Mg(OH)2, etc.) that can be in particulate form and be sized for adsorbing iron and other impurities as the solution is formed via agitation that can occur in the mixing tank as the water is mixed with the other ingredients to form the electrolyte solution. In some embodiments, the one or more impurity removing agents (e.g. MgO, Mg(OH)2, etc.) can be fed to the mixing tank via a source of the impurity removing agents that can be in fluid connection with the mixing tank 13 instead of these materials being included in the source of electrolyte material 23.
[0077] After the solution is mixed for a pre-selected mixing time period to form the electrolyte solution, the formed electrolyte solution can be output from the mixing tank 13 via a mixing tank output conduit 13o that is connected between the mixing tank 13 and a filtration system FS. A pump P can be positioned in fluid connection with the mixing tank output conduit 13o to help drive the flow of the solution to the filtration system FS.
[0078] The filtration system FS can include one or more filters that can be arranged to treat the electrolyte solution in parallel or in series to remove the particulate material (e.g. MgO, Mg(OH)2, etc.) included in the solution to adsorb impurities during the electrolyte solution forming process. The filtration of the particulates can remove the impurities to purify the electrolyte solution so it has less than or equal to a pre-selected impurity content threshold (e.g. less than or equal to a pre-selected iron content threshold, etc.).
[0079] The purified electrolyte solution can be output from the filtration system FS for feeding to an electrolyte storage tank 3 via an electrolyte storage tank feed conduit 3f positioned between the filtration system FS and the storage tank 3. In some embodiments, the filtration system FS can be downstream of a pump P. In other embodiments, the filtration system FS can be upstream of the pump P.
[0080] The electrolyte solution fed to the storage tank 3 and stored in the tank 3 can be at or below a pre-selected impurity threshold (e.g. a pre-selected iron content threshold). The purified electrolyte solution within the storage tank 3 can then be output from the storage tank via an electrolyzer feed conduit 9 that is connected to the storage tank 3 (e.g. via a storage tank output conduit 3o and pump P, etc.). For example, an electrolyzer feed pump P can be actuated to help drive the flow of the purified electrolyte solution from the storage tank 3 to the electrolyzer(s) E via the electrolyzer feed conduit 9.
[0081] Figures 6 and 7 illustrate different exemplary reactor configurations for a reactor 5 that can be utilized in the purification unit 4. In some embodiments, a purification material feed 6 can be fed to the chamber 5c of the reactor to provide purification material for the removal of impurities from the electrolyte solution. Alternatively, the purification material can be positioned in the chamber 5c prior to use and subsequently replaced as may be needed during a time when the reactor 5 is not utilized for purification processing. For instance, the purification material 5m can be positioned in the chamber 5c of the reactor 5 so that there is sufficient material for purification of electrolyte solution for operations to purify the solution for a particular site, set of storage tanks, etc.
[0082] After the reactor 5 is utilized for purification, the purification material 5m may need to be removed or replaced. Such a removal or replacement can be provided via opening of the reactor to remove the purification material and replace it with fresh purification material 5m, for example.
[0083] The inlet and outlet regions of the reactor 5 can include a filtration element to help retain the purification material 5m within the chamber 5c of the reactor. For example, there can be a particulate retention mechanism 5f (e.g. a mesh filter, filter paper, filter cloth, or other type of particulate retention mechanism) positioned adjacent the outlet of the reactor that is connected to the reactor outlet conduit 5o. Such a retention mechanism 5f can also be positioned adjacent the inlet of the reactor within the chamber 5c of the reactor as well in some embodiments.
[0084] The purification material 5m can be in particulate form 5p. Figure 9 illustrates one such example of such a particulate material. The size and shape can be any suitable size and shape (e.g. irregular shaped, spherical shaped, etc.). The sizing can be in the micrometer scale or millimeter scale as noted above as well (e.g. between 0.1 micrometers and 5 millimeters in size, between 0.1 mm and 5 mm in size, between 0.1 micrometers and 5 micrometers in size, etc.).
[0085] Figure 8 illustrates another example of purification material 5m in which the material includes a coating 5cl on a support material 5s. Such a purification material can have voids or apertures to help provide improved contact surface area and may also provide some filtration capability. Such a material can be used instead of or in combination with other types of purification material 5m (e.g. particulate material, etc.).
[0086] Figure 10 illustrates an exemplary embodiment of a process for purification of electrolyte solution. Embodiments of the apparatus 1 can implement an embodiment of this process.
[0087] In a first step S1, electrolyte solution can be provided. Such a solution can be provided via use of mixing tank 13 as noted above, or can be obtained via an electrolyte solution provider as noted above, for example.
[0088] In a second step S2, the electrolyte solution can be purified so that the iron content within the electrolyte solution is at or below a pre-selected iron concentration threshold. Such purification can be provided via use of a reactor 5 and / or filtration system FS as discussed above, for example.
[0089] In a third step S3, the purified electrolyte solution can be fed to a storage tank 3 and / or one or more electrolyzers E. For instance, at least some of the purified electrolyte solution can be fed directly from the purification unit to the electrolyzers as discussed above. As another example, the purified electrolyte solution can be fed to a storage tank and subsequently output from the storage tank for being fed to one or more electrolyzers E as discussed above.
[0090] In an optional fourth step S4 (shown in broken line), a mobile purification system MPS can be decoupled and moved to a new location for purification of electrolyte solution at the new location. Examples of such processing is discussed above. Such a step can be utilized where the purification unit 4 is configured as a mobile purification system MPS, for example.
[0091] Other embodiments of the process may not utilize this optional fourth step S4. For instance, in situations where the purification unit 4 is not configured as a mobile system, this particular step may not be utilized.
[0092] In the event the mobile purification system MPS is connected to a new site for purification at the new location. The first, second, and third steps S1-S3 can again be performed at that new location. Then, the fourth step S4 can again be performed and the mobile purification system MPS can be moved to yet another location such that the process can be repeated multiple times at multiple different spaced apart locations (e.g. different plants, different spaced apart regions within the same industrial complex, etc.).
[0093] It should be appreciated that embodiments can utilize sensor elements to monitor the impurity content within the electrolyte solution for purification processing. Th sensing elements can be positioned at an outlet of the reactor 5, in a filtration system FS, and / or at other locations. The detection of the purity of the electrolyte solution can be utilized to actuate purification processing in situations where the electrolyte solution is determined to have a high impurity content that is outside of a pre-selected impurity concentration criteria for use of the electrolyte solution.
[0094] It should also be appreciated that other modifications can also be made to meet a particular set of criteria for different embodiments of the apparatus 1 or process. For instance, the arrangement of valves, flow meters, temperature sensors, pressure sensors, other sensors, piping, and other conduit elements (e.g., conduit connection mechanisms, tubing, seals, valves, etc.) for interconnecting different units of the apparatus for fluid communication of the flows of fluid between different elements can be arranged to meet a particular facility layout design that accounts for available area of the apparatus, sized equipment of the apparatus, and other design considerations. For instance, the size or type of the equipment can be modified to meet a particular set of design criteria.
[0095] As yet another example, it is contemplated that a particular feature described, either individually or as part of an embodiment, can be combined with other individually described features, or parts of other embodiments. The elements and acts of the various embodiments described herein can therefore be combined to provide further embodiments. Thus, while certain exemplary embodiments of the process, apparatus, system, and methods of making and using the same have been shown and described above, it is to be distinctly understood that the invention is not limited thereto but may be otherwise variously embodied and practiced within the scope of the following claims.
Claims
Claim 1. A process for electrolyte purification, the process comprising: purifying electrolyte solution so that an iron (Fe) content of the electrolyte solution is at or below a pre-selected Fe concentration threshold, the pre-selected Fe concentration threshold being between 0 parts per billion (ppb) Fe and 500 ppb Fe, the purifying of the electrolyte solution including: passing the electrolyte solution through a reactor to contact purification material within a chamber of the reactor for removal of impurities; and / or filtering the electrolyte solution to remove impurities from the electrolyte solution; and feeding the purified electrolyte solution to a storage tank or one or more electrolyzers.Claim 2. The process of claim 1, wherein the purifying of the electrolyte solution includes passing the electrolyte solution through the reactor to contact purification material within the chamber of the reactor for removal of impurities.Claim 3. The process of claim 2, wherein the purifying of the electrolyte solution includes the filtering of the electrolyte solution to remove the impurities from the electrolyte solution.Claim 4. The process of claim 1, comprising: forming the electrolyte solution by mixing electrolyte material with water and at least one purification material within a mixing tank.Claim 5. The process of claim 4, wherein the purifying of the electrolyte solution includes the filtering of the electrolyte solution to remove the purification material from the electrolyte solution to remove impurities from the electrolyte solution.Claim 6. The process of claim 5, comprising: feeding the electrolyte solution from the mixing tank to at least one filtration system for the filtering of the electrolyte solution to remove the purification material from the electrolyte solution to remove impurities from the electrolyte solution.Claim 7. The process of claim 6, comprising: feeding the electrolyte solution that was purified via the at least one filtration system to the storage tank, the storage tank being fluidly connected to at least one electrolyzer.Claim 8. The process of claim 1, comprising: feeding the electrolyte solution that was purified via the purifying of the electrolyte solution to the storage tank, the storage tank being fluidly connected to at least one electrolyzer.Claim 9. The process of claim 1, comprising:feeding the electrolyte solution that was purified via the purifying of the electrolyte solution to the one or more electrolyzers.Claim 10. The process of claim 1, wherein the pre-selected Fe concentration threshold is between 0 ppb and 200 ppb.Claim 11. The process of claim 1, comprising:decoupling a mobile purification system that performed the purifying of the electrolyzer solution from the storage tank after the feeding of the purified electrolyte solution to the storage tank.Claim 12. The process of claim 11, comprising: moving the mobile purification system to another site for purification of electrolyte solution at the site; or moving the mobile purification system to another storage tank for purification of electrolyte solution stored therein.Claim 13. An apparatus for purification of electrolyte solution, comprising: a reactor having a chamber that retains purification material within the chamber, the purification material configured to remove impurities from electrolyte solution to reduce an iron (Fe) content of the electrolyte solution to form a purified electrolyte solution having an Fe content that is at or below a pre-selected Fe content threshold of between 0 parts per billion (ppb) Fe and 500 ppb Fe; a reactor inlet conduit being connected to an inlet of the reactor, the reactor inlet conduit being connectable to a source of the electrolyte solution or a storage tank in which the electrolyte solution is retainable; a reactor outlet conduit being connected to an outlet of the reactor, the reactor outlet conduit being connectable to a storage tank and / or an electrolyzer feed conduit to feed purified electrolyte solution outputtable from the reactor to the storage tank and / or at least one electrolyzer.Claim 14. The apparatus of claim 13, wherein the purification material includes magnesium oxide (MgO) and / or magnesium hydroxide ((Mg(OH)2).Claim 15. The apparatus of claim 13, wherein the apparatus also includes a pump connected to the reactor inlet conduit and a mobile base that supports the pump, the reactor inlet conduit, the reactor outlet conduit, and the reactor.Claim 16. The apparatus of claim 13, comprising: the storage tank, an output conduit of the storage tank being connectable to a pump to feed electrolyte solution within the storage tank to the reactor inlet conduit.Claim 17. The apparatus of claim 13, comprising: the electrolyzer feed conduit, the electrolyzer feed conduit connected to the reactor outlet conduit to fluidly connect the reactor to the at least one electrolyzer to feed the purified electrolyte solution outputtable from the reactor to the at least one electrolyzer.Claim 18. An apparatus for purification of electrolyte solution, comprising: a mixing tank fluidly connected to a source of water, a source of electrolyte material, and a source of purification material to receive the water, the electrolyte material, and the purification material for mixing therein to form electrolyte solution; a filtration system connected to the mixing tank to receive the electrolyte solution from the mixing tank and remove particulates of the purification material from the electrolyte solution to output a purified electrolyte solution having an iron content that is less than or equal to a pre-selected iron (Fe) content threshold, the pre-selected Fe content threshold being between 0 parts per billion (ppb) Fe and 500 ppb Fe.Claim 19. The c apparatus of claim 18, comprising:a storage tank positioned downstream of the filtration system to receive the purified electrolyte solution output from the filtration system.Claim 20. The apparatus of claim 19, comprising:at least one electrolyzer fluidly connected to the storage tank to receive the purified electrolyte solution from the storage tank.