MOLTEN OXIDE ELECTROLYSIS ANODE STRUCTURED FOR OXYGEN GAS COLLECTION

Abstract

A method and system for producing and collecting oxygen gas using molten oxide electrolysis is presented. The system includes a refractory vessel to hold molten oxide material, an anode and cathode, and a collection space at a top portion of the refractory vessel for collecting oxygen gas that is produced at the anode. The anode is configured to include apertures or openings that increase the surface area of the anode to allow for increased production of oxygen gas bubbles during electrolysis. The openings also allow for an increased opportunity for oxygen gas bubbles to ascend directly to the surface, compared to an anode with no such openings, for oxygen gas collection. The system also includes a space at the top of the vessel, above the molten oxide material, configured to collect oxygen from the oxygen gas bubbles that ascend through the molten oxide material from the openings in the anode.

Claims

1. A method for collecting oxygen gas from a process of molten oxide electrolysis, the method comprising: via an electrical current, producing electrolysis in a vessel containing a melted oxide material that includes a liquid cathode at a bottom portion of the vessel and an anode that is i) in a top portion of the vessel, ii) submerged in the melted oxide material, and iii) structured to include openings that extend through the anode; and collecting the oxygen gas in a space above the melted oxide material subsequent to the oxygen gas ascending to the surface from the openings of the anode.

2. The method of claim 1, further comprising removing the collected oxygen gas from the space above the melted oxide material to a container outside the vessel.

3. The method of claim 1, further comprising vibrating the anode to dislodge bubbles of the oxygen gas from surfaces of the openings of the anode.

4. The method of claim 3, wherein the vibrating of the anode is actuated via an anode support member connected to the anode, and wherein the anode support member includes an electrical path that carries the electric current.

5. The method of claim 1, further comprising collecting the oxygen gas in the space above the melted oxide material subsequent to the oxygen gas ascending to the surface from a perimeter of the anode.

6. The method of claim 1, wherein the molten oxide material includes iron oxide and the liquid cathode comprises iron.

7. The method of claim 1, further comprising maintaining a molten state of the molten oxide material via the electrical current.

8. A molten oxide electrolysis (MOE) system for oxygen gas production, the MOE system comprising: a vessel that includes i) an anode and ii) a cathodic electrode in a bottom region of the vessel, wherein the cathodic electrode is configured to be in electrical communication with a molten oxide material in the vessel, the anode and the cathodic electrode are configured to provide an electrical current therebetween for a process of electrolysis of the molten oxide material, the process of electrolysis of the molten oxide material produces a liquid cathode in the bottom region of the vessel and oxygen gas bubbles on the anode, and the anode includes openings configured for formation of the oxygen gas bubbles; and a space configured to be above the molten oxide material and configured to collect oxygen from the oxygen gas bubbles that ascend from the openings in the anode.

9. The MOE system of claim 8, further comprising: a vessel cover, wherein the space above the molten oxide material is enclosed by the vessel cover and the molten oxide material; and an anode support member configured to support the anode and to carry the electrical current to the anode, wherein the anode support member penetrates the vessel cover.

10. The MOE system of claim 9, wherein the anode support member is connected to an actuator that is configured to vibrate the anode via the anode support member so as to dislodge the oxygen gas bubbles from the anode.

11. The MOE system of claim 8, wherein the surface area of the anode is more than five times the surface area of the liquid cathode.

12. The MOE system of claim 8, wherein bottom portions of the anode are beveled to produce a convex surface.

13. The MOE system of claim 8, wherein the anode is substantially disk-shaped.

14. The MOE system of claim 8, wherein the openings in the anode are configured to pass convection cell currents of the molten oxide material.

15. A system for collecting oxygen gas from an electrolysis process, the system comprising: a vessel configured to contain molten oxide material up to a fill level; a cathode configured to be submerged in the molten oxide material at or near the bottom of the vessel; an anode configured to be submerged in the molten oxide material near the top of the vessel and to provide an electric current to the molten oxide material and the cathode, wherein the anode includes openings that extend from a top of the anode to the bottom of the anode; a space between a top cover of the vessel and the fill level for the molten oxide material, the space configured to collect oxygen from oxygen gas bubbles that ascend from the openings in the anode during the electrolysis process; and an output port to channel the collected oxygen gas from the space to a storage container.

16. The system of claim 15, further comprising: an anode support member configured to support the anode and to carry the electrical current to the anode, wherein the anode support member penetrates the top cover via a connection that is impermeable to the oxygen gas.

17. The MOE system of claim 16, wherein the anode support member is connected to an actuator that is configured to vibrate the anode via the anode support member so as to dislodge the oxygen gas bubbles from the anode.

18. The system of claim 15, wherein the anode is substantially horizontal and parallel to the liquid cathode.

19. The system of claim 18, wherein the bottom of the anode is at least partially beveled to produce a convex surface at an intersection between the bottom and vertical sides of the anode.

20. The system of claim 15, wherein the anode is substantially disk-shaped.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0003] The disclosure will be understood more fully from the detailed description given below and from the accompanying figures of embodiments of the disclosure. The figures are used to provide knowledge and understanding of embodiments of the disclosure and do not limit the scope of the disclosure to these specific embodiments. Furthermore, the figures are not necessarily drawn to scale.

[0004] FIG. 1 is a schematic cross-section of a molten oxide electrolysis system with a structured anode, according to some embodiments.

[0005] FIG. 2 is a top view of a structured anode for a molten oxide electrolysis system, according to some embodiments.

[0006] FIGS. 3-5 are top views of example structured anodes for a molten oxide electrolysis system, according to some embodiments.

[0007] FIG. 6 is a schematic cross-section of a portion of a structured anode submerged in molten oxide material during electrolysis, according to some embodiments.

[0008] FIG. 7 is a flow diagram of a process of collecting oxygen gas from a structured anode of a molten oxide electrolysis system, according to some embodiments.

DETAILED DESCRIPTION

[0009] This disclosure describes, among other things, a system and a method for harvesting oxygen gas produced by molten oxide electrolysis (MOE). For example, the method may involve producing oxygen gas from molten oxide material sourced from lunar regolith during electrolysis, though the method may be applied on Earth or Mars. The method is performed using a system that includes a refractory vessel to hold the molten oxide material, an anode and cathode, and a collection space at a top portion of the refractory vessel (hereinafter vessel) for collecting oxygen gas that is produced at the anode. In particular, the anode is configured with apertures or openings in its interior portions. These openings, which extend from a top to a bottom of the anode, increase the surface area of the anode to allow for increased production of oxygen gas bubbles thereon during electrolysis. The openings also allow for an increased opportunity for oxygen gas bubbles to ascend directly to the surface, compared to an anode with no such openings, for oxygen gas collection. The system also includes the aforementioned space at the top of the vessel, above the molten oxide material, configured to collect oxygen from the oxygen gas bubbles that ascend through the molten oxide material from the openings in the anode.

[0010] The system and method for producing oxygen gas, as summarized above, may be particularly useful on the Moon, which has on its surface lunar regolith containing large amounts of oxides and other compounds that may be decomposed by electrolyzing molten lunar regolith. In particular, iron and oxygen are primary constituents of lunar regolith and a molten iron cathode electrolytic cell, as described below, may be used to separate and remove iron and oxygen from the lunar regolith.

[0011] In embodiments, a method may involve a vessel used for an MOE process. The vessel, during operation, includes a molten mixture of metal oxides and a heavier liquid metal cathode that contains a metal or metalloid that may be subsequently extracted from the vessel. In implementations described herein, the liquid metal cathode is iron. Due to its relative density, the heavier liquid metal cathode (e.g., iron) may sink to the bottom of the vessel, which includes a cathodic electrode located at or near the bottom of the vessel. The vessel also includes an anode. The cathodic electrode and the anode may be part of a single electrical circuit that includes a voltage or current source. Accordingly, a current may flow between the anode and cathodic electrode, creating a voltage difference across molten oxide material that is between the anode and cathodic electrode. Per its location in the vessel, the cathodic electrode is configured to be in electrical contact with contents at or near the bottom of the first vessel. The electrical current between the anode and cathodic electrode may allow for a process of electrolysis of the molten oxide material. The electrolysis of the molten oxide material may lead to either the formation of cathode material or the creation of metal that can dissolve into an already existing liquid cathode, which is in electrical contact with the cathodic electrode.

[0012] The MOE process described above generally involves relatively large electrode areas. The molten cathode (iron) of the electrolysis cell is flat and level because the molten iron is in liquid form and forms a pool on the bottom of the vessel due to gravity. The size of the molten cathode is also relatively large because it likely spans across the entire base of the vessel. The anode of the cell is generally formed of a conductive electrode having a surface area that is desirably greater than the area of the cathode.

[0013] The shape of the anode may be configured to have a relatively large surface area and to enable gaseous oxygen, in the form of bubbles, to travel from the anode and to the surface of the relatively highly viscous molten oxide material. Accordingly, the anode may include openings or slots to increase its surface area while simultaneously permitting evolved gas bubbles to escape from the anode in a desired direction for collection at the surface of the molten oxide material. Also, the anode is constructed from a conductive, refractory metal (e.g., niobium) that can withstand temperatures (e.g., about 1,600 C.) of molten oxide material without melting or substantially weakening.

[0014] In some implementations, oxide material used in the method may be derived from lunar regolith. For example, iron oxide may be in lunar regolith, or in minerals found on off-Earth locations and/or objects in the Solar System, such as asteroids, moons, minor-planets, and planets, among other objects. Of course, iron oxide is also present on Earth, and methods described herein may be performed on Earth, the moon, or other bodies listed above, and claimed subject matter is not limited in this respect.

[0015] In various embodiments, a method for collecting oxygen gas from a process of MOE may comprise using an electrical current to produce electrolysis in a vessel containing a melted oxide material that includes a liquid cathode at a bottom portion of the vessel and an anode in a top portion of the vessel. During the electrolysis, oxygen ions (e.g., O.sup.2) flow toward the anode and are oxidized to produce oxygen gas (O.sub.2) bubbles. Simultaneously, metal ions are reduced as they flow toward the cathode (e.g., current collector). The metal that initially forms close to the bottom of the vessel is molten and negatively charged, and thus it will act as the cathode of the MOE cell.

[0016] The anode may be submerged in the melted oxide material and structured to include openings through interior portions of the anode. For example, the geometry of the anode includes slots or apertures having any of a number of shapes, such as circles, rectangles, arcs, etc. This geometry, including the openings, increases the surface area of the anode and allows for oxygen gas bubbles to dislodge from the anode and travel relatively easily by ascending to the surface of the molten oxide material for collection. Because the molten oxide material (e.g., molten regolith) has a relatively high viscosity (e.g., somewhat similar to the viscosity of honey at room temperature), increasing the opportunity or likelihood for oxygen gas bubbles to ascend from the anode by providing the openings in the anode may substantially improve the efficiency of collecting oxygen gas produced at the anode. The oxygen gas bubbles provide oxygen gas to an enclosed volume above the surface of the molten oxide material upon their arrival at the surface. The oxygen gas may then be collected from the system for storage and later use, for example.

[0017] In some implementations, the anode may be vibrated to dislodge bubbles of the oxygen gas from surfaces of the anode. For example, vibrations may be generated by an actuator (e.g., a mechanical transducer) and transferred to the anode via an anode support member that is configured to support the anode. The anode support member may also include an electrical path that carries electric current to the anode for the electrolysis process.

[0018] In some implementations, the electrical current for the electrolysis process maintains the molten state of the molten oxide material during the electrolysis process. For example, a method for initially heating and melting the oxide material may be different from Joule heating by the electrical current for the electrolysis process. In some implementations, induction heating or electrical Joule heating from conductors outside the oxide material may be used for initially melting the oxide material. In some cases, the oxide material may be molten before being placed in the electrolysis vessel.

[0019] Though openings that extend through an anode may result in increased oxygen production, as herein described, including such openings may be a relatively poor design choice compared to anodes without openings for a number of reasons. For example, anodes for MOE processes are generally made of refractory materials that are conductive and can withstand relatively high temperatures and still retain structural stability and strength. Unfortunately, refractory materials may be relatively structurally weak compared to materials that cannot be used in high-temperature environments. Thus, placing openings in an anode made of refractory materials may compromise the already-deficient strength of these materials. Even so, the benefits of including openings in an anode, as described for the particular embodiments described herein, may likely outweigh the downsides of including the openings.

[0020] FIG. 1 is a schematic cross-section of an MOE system 100 that includes a structured anode 102, according to some embodiments. Various portions of the system, as illustrated, are not necessarily to scale. MOE system 100 generally comprises electrical and mechanical components that are interfaced with one another in various configurations. The MOE system may further comprise one or more computer processors configured to execute computer-readable instructions, which may be directed to controlling at least some of the electrical and mechanical components, such as controlling the vertical positioning of the anode, for example.

[0021] MOE system 100 may include a vessel 104 (e.g., an electrolysis vessel), anode 102 protruding into the vessel from above, and a cathodic electrode 106, which may be located at or near a bottom portion 108 of vessel 104. A perimeter side 109 of anode 102 contributes to the total surface area of the anode. Additionally, as explained below, anode 102 may include openings 110 that, among other things, increase the total surface area of the anode, as compared to the area of a disk without such openings. Openings 110 may extend from a top of the anode to a bottom of the anode. Cathodic electrode 106 may be configured to be in electrical contact with a lower portion of contents, such as a liquid cathode 111, contained in vessel 104. The anode and cathodic electrode may be part of a single electrical electrolysis circuit that includes a voltage or current source (not illustrated). Accordingly, a current may flow between the anode and cathodic electrode, creating a voltage difference across molten oxide material 112 that is between the anode and cathodic electrode. For example, in some implementations, a generic composition of oxides of the oxide material may be: SiO.sub.2+Al.sub.2O.sub.3+MgO+FeO+CaO with trace alkali oxides and halides. The electrical current between the anode and cathodic electrode may allow for a process of electrolysis of oxide material 112. Distances 114 between anode 102 and liquid cathode 111 may be varied to adjust voltage and/or current of the electrolysis circuit. Such variation may be useful to account for varying resistivity of molten oxide material 112 and liquid cathode 111, for example. As explained above, the electrolysis of molten oxide material 112 may produce the liquid cathode, which, in embodiments described herein, is denser than the surrounding molten oxide material (e.g., 112). Accordingly, the liquid cathode will remain sunk toward the bottom of vessel 104 and thus be in electrical contact with cathodic electrode 106.

[0022] Vessel 104 (e.g., a refractory vessel) may have two or three layers in some implementations. For example, an exterior layer may be made of insulating material to reduce heat loss. An interior layer, configured to be in contact with high temperature oxide electrolyte, may comprise a material that is chemically compatible with the electrolyte. For example, the material may be resistant to extreme temperatures, pressure, and chemicals. An intermediate layer of the vessel may provide the vessel with stability in terms of structure, temperature, or other characteristics. Claimed subject matter, however, is not limited to any particular details or type of vessel.

[0023] Vessel 104 may include a removeable lid 116 configured to be placed on the top edge of vessel 104 with a gas impermeable seal 118 therebetween. For example, lid 116 may be removed for placement of oxide material (e.g., lunar regolith) into vessel 104. In some implementations, the oxide material may be molten before such placement into vessel 104, such as from a melting process that occurs in another vessel. In other implementations, the oxide material may not yet be melted and will be heated to a molten state in vessel 104 by induction heating or electrical resistive heating (not illustrated), just to name a few examples. Claimed subject matter is not limited in this respect. In some implementations, lid 116 may include material feed apertures (not illustrated) to introduce particles of ore, metal oxide electrolyte, or other additives into the vessel 104 without removing the lid. Lid 116 may also include injection apertures as well as sensing apertures (not illustrated). The access ports or apertures in lid 116 may be threaded so that they can be sealed with a cap during operation to restrict or prevent oxygen gas release, for example.

[0024] A space 120 may be formed by vessel 104, removeable lid 116, and a top surface 122 of molten oxide material 112. In some implementations, vessel 104 may be configured to contain molten oxide material 112 up to a predetermined fill level 123, which may be a guideline for filling the vessel or a maximum fill height per design considerations, for example. Vessel 104, removeable lid 116, or their combination may include an output port 124 to channel collected oxygen gas from space 120 to a storage container (not illustrated). For example, output port 124 may be an opening in a side of vessel 104 or may be an intentionally-configured gap in seal 118 that is open to tubes or pipes 126 that convey the oxygen gas, as indicated by arrow 128, to the storage container.

[0025] MOE system 100 may also include an anode support member 130 that is vertically translatable to allow the anode support member to have a vertical degree of freedom, as indicated by arrow 132. Anode support member 130, which may penetrate lid 116 with an oxygen impermeable seal 134, may include an electrical path 136 (e.g., a cable or other conductor) to provide electric current to anode 102. In some implementations, anode support member 130 may be physically coupled with a mechanical transducer or actuator 138 that generates vibratory motion that is transmitted, via the anode support member, to anode 102. Vibrational motion may be used to dislodge oxygen gas bubbles 140 that form on anode 102, for example. In some implementations, anode support member 130 may be electrically insulated or isolated from the molten oxide material so that the anode support member is protected from chemical reactions (e.g., oxidation) with the surrounding molten oxide material.

[0026] Anode support member 130 may be configured to vary the depth 142 at which anode 102 is submerged below top surface 122 of the molten oxide material. Varying depth 142 consequentially varies distances 114 between bottom surfaces of anode 102 and liquid cathode 111. If portions of the liquid cathode are removed (e.g., tapped), surface 122 will consequently lower and anode support member 130 may respond by lowering anode 102 to maintain a constant depth 142, for example.

[0027] FIG. 2 is a top view of structured anode 102 for MOE system 100, according to some embodiments. In particular, the cross-section of anode 102 illustrated in FIG. 1 is section A-A identified in FIG. 2. Structured anode 102 is described as structured because such an anode includes one or more openings, in contrast to a non-structured disk without openings. In the illustrated example, anode 102 (the word structured need not be used in each instance herein when the context and configuration of anode is clear) includes openings 110 through interior portions of anode 102.

[0028] As discussed above, the MOE processes described herein generally involve relatively large electrode areas for at least the reason that the area of the liquid cathode is relatively large, spanning across the entire base of the vessel due to gravity. The area of the anode is preferably larger than the area of the cathode. Accordingly, openings 110 increase the surface area of anode 102 as compared to an equivalent structure (e.g., a disk) without openings. The area of the perimeter side 109 also contributes to the total surface area of anode 102. Anode 102 has a general shape similar to or the same as a disk that is oriented horizontally in vessel 104 of MOE system 100. This in contrast to anodes that are generally cylindrical in a vertical orientation in other electrolysis processes. The horizontal disk configuration of the anode corresponds to the horizontal aspect of the liquid cathode at the bottom of vessel 104. This correspondence may allow for a more uniform electrical current density through molten oxide material 112, as compared to an electrolytic cell having smaller electrodes relative to the size of the vessel.

[0029] In addition to the shape of the anode configured to have a relatively large surface area to correspond to the relatively large area of liquid cathode, openings 110 in anode 102 enable oxygen gas bubbles to travel relatively easy from the anode to the surface of the molten oxide material. This is explained in greater detail below.

[0030] Anode support member 130 may be attached to anode 102 at a center of the anode, between openings 110. As described below, MOE system 100 may include more than one anode support member, depending at least in part on a configuration of openings in the anode. At least a bottom portion of anode support member 130 may, like anode 102, be constructed from a conductive, refractory metal (e.g., tantalum, niobium, molybdenum, tungsten, etc.) that can withstand prolonged temperatures of molten oxide material without melting. The attachment of anode support member 130 to anode 102 is electrically conductive to carry all, in the case of one anode support member, the electrical current to be used in the MOE process. If more than one anode support member is used, then electrical current may be provided to the anode by one or more of the anode support members.

[0031] In some implementations, anode support member 130 may be physically coupled with actuator 138 to transmit vibratory motion to anode 102. Such vibrations may have a frequency and intensity that encourages dislodging of oxygen gas bubbles that form on the anode. Even while effectively dislodging oxygen gas bubbles, such combinations of frequency and intensity of vibrations may have a relatively small effect on the mechanical integrity of anode 102 and the attachment between anode 102 and anode support member 130.

[0032] FIGS. 3-5 are top views of example structured anodes for an MOE system, according to some embodiments. In FIG. 3, anode 300 includes openings 302, which are generally rectangular and distributed in such a way that an anode support member 304, extending perpendicularly from anode 300, can provide sufficient mechanical strength to the entire anode area. In FIG. 4, anode 400 includes openings 402, which are generally circular and distributed in such a way that two anode support members 404, which may extend perpendicularly or at an angle from anode 400, can provide sufficient mechanical strength to the entire anode area. In FIG. 5, anode 500 includes openings 502, which are generally portions of circular arcs and distributed in such a way that three anode support members 504, extending perpendicularly or at an angle from anode 500, can provide sufficient mechanical strength to the entire anode area. The openings of these anodes are merely a few examples of possible shapes and configurations.

[0033] Surface areas of anodes 300, 400, and 500 are increased by the presence of their respective openings (e.g., 302, 402, and 502). For example, though not viewable in the top view of FIG. 4, sides 406 of openings 402, as well as the perimeter side 408, of anode 400 contribute to the total surface area of anode 400. The contribution of the side surface areas of openings 402 to the total area of the anode may lead to an increase in oxygen gas bubble formation on the anode surfaces, as compared to an anode without openings 402.

[0034] FIG. 6 is a schematic cross-section of a portion 600 of a structured anode 602 that includes an opening 603 and is submerged in molten oxide material 604 during electrolysis, according to some embodiments. For example, anode 602 may be the same as or similar to anode 102 and molten oxide material 604 may be the same as or similar to 112 in MOE system 100. Anode 602 may be submerged below the surface 606 of the molten oxide material by a depth 608, though the anode is configured to move vertically so that this depth can change.

[0035] The electrolysis process produces oxygen gas bubbles 610 on substantially all the surfaces of anode 602. For efficient and successful oxygen gas collection, the oxygen gas bubbles dislodge from the surfaces of the anode and ascend to surface 606 where, just above this surface, oxygen from the oxygen gas bubbles accumulates in a space 612 (e.g., similar to or the same as 120).

[0036] From their creation at the anode surfaces to reaching surface 606, there are two key steps that the oxygen gas bubbles perform. First, the oxygen gas bubbles dislodge from the anode surface. Second, the oxygen gas bubbles travel through relatively viscous molten oxide material 604 to reach surface 606. Though dislodging of the oxygen gas bubbles naturally occurs fairly continuously, in some implementations anode 602 may be vibrated to further prompt the oxygen gas bubbles to dislodge. Travel to surface 606 of the dislodged oxygen gas bubbles is driven by the bubbles' buoyancy, wherein gravity allows the bubbles to float to the surface, as indicated by arrow 613, for example. Even with the buoyant force, however, the path each oxygen gas bubble takes to reach surface 606 may strongly affect its travel time. Accordingly, the rate of oxygen collection in space 612 may similarly be affected.

[0037] In some implementations, a bottom surface 614 may be at least partially concave to allow for reduced resistance to bubble travel 616 from the bottom of anode 602. For example, the bottom of anode 602 may be at least partially beveled to produce a convex surface at an intersection between the bottom and vertical sides of the anode. In contrast to having such a concave surface, for example, oxygen gas bubbles may encounter relatively more resistance to upward buoyant travel 618 at a corner 620 that intersects a vertical surface with a flat bottom of anode 602. In some implementations, an upward edge 622 may be configured to enable dislodging of oxygen gas bubbles. For example, if edge 622 were smoothly beveled, then surface tension may cause a bubble traveling upward on the side of anode 602, as indicated by arrow 624, to travel onto the top 626 of the anode instead of dislodging at corner 622. Thus, corner 622 may be a relatively sharp ninety-degree corner so that bubbles encountering the sharp corner may readily dislodge from the anode.

[0038] In some implementations, openings in structured anodes, such as 603, may provide an upward path for convection currents 628 in molten oxide material 604. Convection currents may provide an upward driving force to the buoyant oxygen gas bubbles, causing them to rise relatively fast to surface 606. Openings at or near a center region of a structured anode may experience such upward convection currents if the molten oxide material at the center region of a vessel is hotter than the molten oxide material nearer to the sides of the vessel. This may likely be the case because heat loss from the molten oxide material is through the sides of the vessel, causing this part of the molten oxide material to be cooler than at the central part.

[0039] FIG. 7 is a flow diagram of a process 700 of collecting oxygen gas from a structured anode of an MOE system, according to some embodiments. The process may be performed by an operator, which may be a person or persons, a computer processor executing computer-readable code, or a combination thereof. Process 700 may be performed by the operator using MOE system 100, for example.

[0040] At 702, by using an electrical current, the operator may produce electrolysis in a vessel containing a melted oxide material that includes a liquid cathode at a bottom portion of the vessel and an anode in a top portion of the vessel. The anode may be submerged in the melted oxide material and may be structured to include openings that extend through the anode. At 704, the operator may collect the oxygen gas in a space above the melted oxide material subsequent to the oxygen gas ascending to the surface from the openings of the anode.

[0041] The foregoing description, for purposes of explanation, used specific nomenclature to provide a thorough understanding of the disclosure. However, it will be apparent to one skilled in the art that the specific details are not required in order to practice the systems and methods described herein. The foregoing descriptions of specific embodiments or examples are presented by way of examples for purposes of illustration and description. They are not intended to be exhaustive of or to limit this disclosure to the precise forms described. Many modifications and variations are possible in view of the above teachings. The embodiments or examples are shown and described in order to best explain the principles of this disclosure and practical applications, to thereby enable others skilled in the art to best utilize this disclosure and various embodiments or examples with various modifications as are suited to the particular use contemplated. It is intended that the scope of this disclosure be defined by the following claims and their equivalents.