Systems and methods for reducing water consumption and recovering activated metals from aluminum-water reactions

Abstract

Systems and methods relating to aluminum-water reaction, hydrogen gas production, and recovery of activated metals are generally described. According to some embodiments, a method of producing hydrogen gas is described that includes reacting an activated aluminum composition, including aluminum and an activated composition, with a solution including water and at least one selected from the group of an ionic salt, a hydroxide, and an acid in a reaction chamber to produce hydrogen gas and one or more reaction products, and forming a separate phase including the activated composition after reacting the activated aluminum with the water.

Description

[Technical field]

[0001] (CROSS REFERENCE TO RELATED APPLICATIONS) This application claims the benefit under 35 U.S.C. Section 119(e) of U.S. Provisional Application No. 63 / 209,342, filed June 10, 2021, the disclosure of which is incorporated by reference in its entirety.

[0002] Systems and methods relating to aluminum-water reaction, hydrogen gas production, and activated metal recovery are generally described. [Background technology]

[0003] Hydrogen gas is widely recognized as a promising non-polluting fuel carrier for a more sustainable energy economy compared to fossil fuels. Redox reactions involving metals can produce hydrogen on demand, eliminating the costs and safety concerns of storing hydrogen as a gas or liquid at high pressure. Aluminum (Al), for example, has an energy density about twice that of diesel fuel and more than 40 times that of lithium ions, and reacts with water to produce hydrogen at room temperature and atmospheric pressure. However, using aluminum as a bulk fuel source presents certain challenges associated with water consumption. Summary of the Invention [Means for solving the problem]

[0004] Systems and methods relating to aluminum-water reaction, hydrogen gas production, and activated metal recovery are generally described. The subject matter of the present disclosure involves, in some cases, interrelated products, alternative solutions to a particular problem, and / or a number of different uses of one or more systems and / or articles.

[0005] According to some embodiments, a method of producing hydrogen gas is described that includes reacting an activated aluminum composition comprising aluminum and an activation composition with a solution comprising water and at least one selected from the group of an ionic salt, a hydroxide, and an acid in a reaction chamber to produce hydrogen gas and one or more reaction products, and forming a separate phase comprising the activation composition after reacting the activated aluminum with the water.

[0006] In one embodiment, a system is described that includes a first reservoir configured to contain an active aluminum composition comprising aluminum and an activating composition; a second reservoir configured to contain an ionic salt, hydroxide, and / or acid; and a reaction chamber in fluid communication with the first reservoir and the second reservoir, wherein the first reservoir is configured to dispense the active aluminum into the reaction chamber and the second reservoir is configured to dispense the ionic salt, hydroxide, and / or acid into the reaction chamber, and wherein the active aluminum reacts with water in the presence of the ionic salt, hydroxide, and / or acid in the reaction chamber to produce hydrogen gas and one or more reaction products.

[0007] According to some embodiments, a system includes a first reservoir configured to contain an active aluminum composition comprising aluminum and an activating composition; a second reservoir configured to contain a solution comprising water and an ionic salt, hydroxide, and / or acid dissolved in the water; and a reaction chamber in fluid communication with the first reservoir and the second reservoir, wherein the first reservoir is configured to dispense the active aluminum into the reaction chamber and the second reservoir is configured to dispense the solution into the reaction chamber, wherein the active aluminum is ionized. A system is described that includes a reaction chamber configured to react with water in the presence of an ionic salt, hydroxide, and / or acid to produce hydrogen gas and one or more reaction products, where the amount of ionic salt, hydroxide, and / or acid is sufficient to cause the activated composition to form a separate phase after the activated aluminum reacts with the water; a separation system configured to separate the activated composition from the one or more reaction products; and a collection chamber in fluid communication with the reaction chamber, the collection chamber configured to receive the separate phase of the activated composition from the reaction chamber.

[0008] Other advantages and novel features of the present disclosure will become apparent from the following detailed description of various non-limiting embodiments thereof, when considered in conjunction with the accompanying drawings. In cases where the present specification and any document incorporated by reference include conflicting and / or inconsistent disclosure, the present specification shall control. [Brief description of the drawings]

[0009] Non-limiting embodiments of the present disclosure will be described by way of example with reference to the accompanying figures, which are schematic and are not intended to be drawn to scale. In the figures, each identical or nearly identical component shown is typically represented by a single number. For purposes of clarity, not every component is labeled in every figure, and not every component of each embodiment of the present disclosure is shown, unless illustration is necessary to enable a person skilled in the art to understand the disclosure.

[0010] [Figure 1A] FIG. 1A shows a schematic top view of a system comprising a first reservoir, a second reservoir, and a reaction chamber, according to one embodiment.

[0011] [Figure 1B] FIG. 1B shows a schematic side view of the system of FIG. 1A, according to one embodiment.

[0012] [Figure 2A] FIG. 2A shows a schematic top view of a system comprising a first reservoir, a second reservoir, a third reservoir, and a reaction chamber, according to an embodiment.

[0013] [Figure 2B] FIG. 2B shows a schematic side view of the system of FIG. 2A, according to one embodiment.

[0014] [Figure 3A] FIG. 3A shows a schematic top view of a system comprising a first reservoir, a second reservoir, a reaction chamber, and a separation system, according to an embodiment.

[0015] [Figure 3B] FIG. 3B shows a schematic side view of the system of FIG. 3A, according to one embodiment.

[0016] [Figure 4A] FIG. 4A shows a schematic top view of a system comprising a first reservoir, a second reservoir, one or more processors, a reaction chamber, and a separation system according to an embodiment.

[0017] [Figure 4B] FIG. 4B shows a schematic side view of the system of FIG. 4A, according to one embodiment.

[0018] [Figure 5A]FIG. 5A shows a schematic top view of a system comprising a first reservoir, a second reservoir, one or more processors, a reaction chamber, a separation system, and a collection chamber, according to one embodiment.

[0019] [Figure 5B] FIG. 5B shows a schematic side view of the system of FIG. 5A, according to one embodiment.

[0020] [Figure 6] FIG. 6 shows the hydrogen yield of the reaction between activated aluminum and water in the presence of NaOH as a function of pH, according to certain embodiments.

[0021] [Figure 7] FIG. 7 shows the reaction products of the reaction between activated aluminum and water in the presence of NaOH, according to certain embodiments.

[0022] [Figure 8] FIG. 8 shows a schematic flow diagram of a system for reacting activated aluminum with water in the presence of NaOH, according to an embodiment.

[0023] [Figure 9A] FIG. 9A shows a scanning electron microscope (SEM) image of an activated composition after aluminum-water reaction, according to an embodiment.

[0024] [Figure 9B] FIG. 9B shows an energy dispersive X-ray spectroscopy (EDS) atomic map of the activated composition shown in FIG. 9A, according to an embodiment.

[0025] [Figure 10A] FIG. 10A shows an SEM image of aggregates resulting from an aluminum-water reaction without an ionic salt, hydroxide, or acid, according to an embodiment.

[0026] [Figure 10B]FIG. 10B shows an EDS atomic map of the aggregates shown in FIG. 10A. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0027] Detailed Description Aluminum metal and water react to produce hydrogen gas according to one of the following exothermic reactions, shown in reactions (1) and (2). 2Al+4H2O→3H2+2AlO(OH)+Q1 (1) 2Al+6H2O→3H2+2Al(OH)3+Q2 (2) where Q1 and / or Q2 are 840 kJ to 880 kJ of heat depending on the extent of reaction. However, under ambient conditions, an oxide layer forms on the surface of aluminum as it is exposed to atmospheric oxygen, thus interfering with the ability of the underlying pure aluminum metal to not substantially react with water. Activating compositions can be used to penetrate into the grain and / or subgrain boundaries of the aluminum, thus disrupting the oxide layer and promoting the reaction between the aluminum and water.

[0028] The inventors have realized that an obstacle to achieving the full potential of aluminum as a fuel source is the inability to easily recover the activated composition after the reaction between aluminum and water is complete. The components of the activated composition (e.g., gallium and / or indium) may separate from each other during the course of the reaction, thus increasing their individual melting points, allowing one or more of the components of the activated composition (e.g., gallium) to oxidize, and / or dispersing one or more components of the activated composition into microdroplets that are dispersed in the reaction product, all of which may complicate the separation of the activated composition from the mixture of reaction products. Conventional methods of recovering the activated composition use complex and inefficient chemical processes, resulting in low recovery yields. This is in contrast to the mechanical separation-based process disclosed herein.

[0029] Another obstacle associated with realizing the potential of aluminum as a fuel source is that the reaction between aluminum and water necessitates significant amounts of excess water than suggested by the stoichiometry in either reaction (1) or (2) in order to reach maximum yield of hydrogen. In some conventional cases, for example, maximum hydrogen yield is not achieved until nearly ten times the stoichiometric water ratio is employed. Requiring large amounts of excess water is impractical for closed system power applications that store both aluminum and water. Furthermore, the energy density and specific energy of such systems are significantly reduced, resulting in aluminum becoming a less viable fuel option.

[0030] The present inventors have recognized and appreciated that reacting the activated aluminum composition with water in the presence of an ionic salt (e.g., NaCl), hydroxide (e.g., NaOH), and / or acid (e.g., HCl) provides the tandem effect of allowing recovery of the activated composition used to activate the aluminum while also reducing water consumption. Without wishing to be bound by theory, reacting the activated aluminum with water in the presence of an ionic salt, hydroxide, and / or acid prevents the components of the activated composition from separating from each other and allows the activated composition to be separated from excess reactants and / or other reaction products via some density-driven mechanical process. Recovering the activated composition is advantageous because the activated composition is expensive and possibly harmful to the environment in large quantities. In addition, including an ionic salt, hydroxide, and / or acid during the reaction of the activated aluminum with water can increase hydrogen yield. As discussed in more detail herein, for example, the ionic cations and / or ionic anions (e.g., NaCl, NaOH ... + , Cl -) may adhere to the surface of the activating composition. Without wishing to be bound by theory, the ionic cations and / or anions may advantageously affect the zeta potential and / or surface tension of the activating composition such that the activating composition remains a colloidal composition after the reaction between the active aluminum and water.

[0031] As used herein, the term "ionic salt" is given its ordinary meaning in the art and generally refers to a chemical compound consisting of an ionic assembly of a cation and an anion. The term "hydroxide" is also given its ordinary meaning in the art and generally refers to a compound of the chemical formula OH - In some embodiments, the hydroxide may be a base (e.g., a chemical compound that can either accept a proton, such as a Bronstead-Lowry base, or donate an electron pair, such as a Lewis base). In certain embodiments, the hydroxide may be an ionic salt. The term "acid" is also given its ordinary meaning in the art and generally refers to a chemical compound that can either donate a proton (i.e., a Bronstead-Lowry acid) or accept an electron pair (i.e., a Lewis acid). According to some embodiments, the acid may be an ionic salt.

[0032] After the reaction between the activated aluminum composition and water, it may be desirable to separate and / or recover the activated composition. According to certain embodiments, the use of ionic salts, hydroxides, and / or acids advantageously allows the activated composition to be phase isolated, as explained in more detail below, thus allowing for separation and recovery of the activated composition via simple mechanical separation due to the activated composition being denser than the reactants and reaction products. Without wishing to be bound by theory, it is believed that the ionic cations (e.g., Na + ) and / or ionic anions (e.g., Cl -One or more components of ionic salts, hydroxides, and / or acids such as cations, hydroxides, and / or acids, such as cations, hydroxides, and / or acids, may adhere and / or otherwise aggregate on the surface of the activating composition as the activating composition activates the aluminum. The adhesion of the ionic cations to the surface of the activating composition prevents separation and / or oxidation of the components of the activating composition, thus allowing for simple mechanical separation of the activating composition.

[0033] The use of ionic salts, hydroxides, and / or acids may also reduce the amount of water consumption required to reach maximum yield of hydrogen, or conversely, increase hydrogen yield for a given amount of water. Without wishing to be bound by theory, for example, hydroxides (e.g., NaOH) may be employed in certain non-limiting embodiments to increase the alkalinity of the water reactant, thus favoring the formation of Al(OH)3 as shown in reaction (2), and driving the reaction to completion. In certain embodiments where AlOOH is formed as shown in reaction (1), water may intercalate between the layers of the reaction product, thus preventing water from reaching the aluminum fuel.

[0034] A separate phase of the activating composition may, in some embodiments, comprise a colloidal aggregate of the activating composition dispersed within an additional phase, which may, in some embodiments, comprise one or more reaction products (e.g., AlO(OH), Al(OH)3 as shown in reactions (1) and (2)), unreacted water, and / or excess and / or residual ionic salts, hydroxides, and / or acids (e.g., dissolved and / or suspended in water).

[0035] In some embodiments, it may be desirable to maintain a mixture of an activating composition and one or more reaction products in a gel state to facilitate separation of the activating composition from the one or more reaction products while avoiding crystallization of the one or more reaction products. In such embodiments, a mixture comprising an activating composition and one or more reaction products may contain any of a variety of suitable amounts of water to maintain a gel state. In some embodiments, for example, the mixture contains water in an amount greater than or equal to 1% by weight, greater than or equal to 5% by weight, greater than or equal to 10% by weight, greater than or equal to 15% by weight, or greater than or equal to 20% by weight, relative to the total weight of the mixture. In some embodiments, the mixture contains water in an amount less than or equal to 25% by weight, less than or equal to 20% by weight, less than or equal to 15% by weight, less than or equal to 10% by weight, or less than or equal to 5% by weight, relative to the total weight of the mixture. Combinations of the above-listed ranges are also possible (e.g., the mixture contains water in an amount between greater than or equal to 1% and less than or equal to 25% by weight, relative to the total weight of the mixture, and the mixture contains water in an amount between greater than or equal to 10% and less than or equal to 15% by weight, relative to the total weight of the wet activation composition). Other ranges are also possible.

[0036] The systems described herein may, in some embodiments, include a separation mechanism (e.g., a separation system) configured to separate the activated composition from one or more reaction products. Any of a variety of suitable separation systems may be employed. In some embodiments, for example, the separation system is a gravity-based system and / or a separation funnel-based system. The gravity-based system may, for example, include a stepwise fluid connection between the reaction chamber and the separation system, where at least a portion of the reaction chamber is positioned at a height higher than the separation system relative to the direction of gravity such that the separated phase of the activated composition flows vertically downward under gravity to the separation system. A separation funnel may be used in some embodiments, where the separation funnel is configured to perform an extraction to separate the separated phase of the activated composition from the additional phase. According to some embodiments, an electric field may be applied to separate the activated composition. For example, in certain embodiments, the activated composition and one or more reaction products may undergo electrowetting. Without wishing to be bound by theory, the activated composition may form an electronic double layer in the presence of an ionic solution. For example, in some embodiments, the activating composition may be at least partially positively charged in an alkaline solution or at least partially negatively charged in an acidic solution, in some such embodiments, an external electric field (e.g., electrowetting) may be applied to separate the activating composition.

[0037] After separating the activated composition from the additional phase, the activated composition may be flowed to a collection chamber, which is in fluid communication with the reaction chamber and the separation system. In some embodiments, the collection chamber is configured to receive the separated phase of the activated composition and maintain the moistened and activated composition. According to some embodiments, it may be advantageous to avoid substantially drying the activated composition after separation, in order to avoid oxidation and / or separation of one or more components of the activated composition.

[0038] In certain embodiments, the recovery chamber of the system may also be configured to recirculate the activation composition for use in subsequent activation of additional aluminum for the aluminum-water reaction.

[0039] According to some embodiments, advantageously large amounts of the activated composition can be recovered after the reaction between active aluminum and water. In some embodiments, for example, more than or equal to 95%, more than or equal to 96%, more than or equal to 97%, more than or equal to 98%, more than or equal to 99%, or more than or equal to 99.9% of the activated composition is recovered after the reaction between active aluminum and water. In some embodiments, less than or equal to 100%, less than or equal to 99.9%, less than or equal to 99%, less than or equal to 98%, less than or equal to 97%, or less than or equal to 96% of the activated composition is recovered after the reaction between active aluminum and water. Combinations of the ranges listed above are also possible (e.g., between more than or equal to 96% and less than or equal to 100% of the activated composition is recovered after the reaction between active aluminum and water, and between more than or equal to 98% and less than or equal to 99.9% of the activated composition is recovered after the reaction between active aluminum and water).

[0040] According to certain embodiments, described herein are methods for producing hydrogen gas by reacting an activated aluminum composition with water in the presence of an ionic salt, hydroxide, and / or acid. In some embodiments, for example, the method includes dispensing an activated aluminum composition (e.g., aluminum activated by an activation composition) and an ionic salt, hydroxide, and / or acid into a reaction chamber. As discussed in more detail below, the active aluminum composition may be dispensed into the reaction chamber from a first reservoir, and the ionic salt, hydroxide, and / or acid may be dispensed into the reaction chamber from a second reservoir.

[0041] In some embodiments, the method includes reacting an activated aluminum composition, including aluminum and an activating composition, with a solution including water and at least one selected from the group of ionic salts, hydroxides, and acids in a reaction chamber. Hydrogen gas and one or more reaction products (e.g., AlO(OH), Al(OH)3 as shown in reactions (1) and (2)) can be produced as a result of reacting the activated aluminum composition with a solution including water and ionic salts, hydroxides, and / or acids. Hydrogen gas may be removed from the reaction chamber through any of a variety of suitable means, including, for example, through one or more gas outlets in fluid communication with the reaction chamber. In some embodiments, heat generated from the reaction (e.g., Q1, Q2 as shown in reactions (1) and (2)) may be recovered and used for one or more applications, such as, for example, heat pumps and / or direct heating applications.

[0042] According to some embodiments, the method includes forming a separate phase including the activated composition after reacting the activated aluminum composition with water. Without wishing to be bound by theory, as described herein, the separate phase including the activated composition may be formed by the incorporation of ionic cations (e.g., Na) into the surface of the activated composition. + ) and / or ionic anions (e.g., Cl - ) is formed due to adhesion of the activated composition to the one or more reaction products via mechanical separation, as described herein. The activated composition may then, in some embodiments, be flowed to a collection chamber, and the activated composition may then be recovered and / or recycled for use in another aluminum-water reaction.

[0043] The ionic salt, hydroxide, and / or acid may be provided in any desired form. In some embodiments, for example, the ionic salt, hydroxide, and / or acid is dissolved and / or suspended in a solution (e.g., water or an aqueous solution). In other embodiments, the ionic salt, hydroxide, and / or acid is provided as a solid material. For example, in some embodiments, the ionic salt, hydroxide, and / or acid may be provided as a powder that can be added to a suitable reaction chamber in which the water and active aluminum are to be reacted.

[0044] According to certain embodiments, the ionic salts include NaCl, KCl, NaHCO3, MgCl2, CaCl2, and / or Al2(SO4)3. Other ionic salts are also possible.

[0045] In some embodiments, the hydroxides include NaOH, KOH, Ca(OH)2, and / or Mg(OH)2. Other hydroxides are also possible.

[0046] In certain embodiments, the acid includes HCl, H2SO4, and / or CH3COOH. Other acids are also possible.

[0047] As explained above, the ionic salt, hydroxide, and / or acid may be dissolved in a solution (e.g., water or an aqueous solution). The ionic salt, hydroxide, and / or acid may have any of a variety of suitable concentrations. In some embodiments, for example, the concentration of the ionic salt, hydroxide, and / or acid dissolved in the solution (e.g., water or an aqueous solution) is greater than or equal to 0.1M, greater than or equal to 0.5M, greater than or equal to 1M, greater than or equal to 1.5M, greater than or equal to 2M, greater than or equal to 2.5M, greater than or equal to 3M, greater than or equal to 3.5M, greater than or equal to 4M, greater than or equal to 4.5M, greater than or equal to 5M, greater than or equal to 6M, greater than or equal to 7M, greater than or equal to 8M, greater than or equal to 9M, or greater than that. In certain embodiments, the concentration of the ionic salt, hydroxide, and / or acid dissolved in the solution is less than or equal to the solubility limit of the ionic salt, hydroxide, and / or acid in the solution. For example, in some embodiments, the concentration of the ionic salt, hydroxide, and / or acid dissolved in the solution (e.g., water or an aqueous solution) is less than or equal to 10M, less than or equal to 9M, less than or equal to 8M, less than or equal to 7M, less than or equal to 6M, less than or equal to 5M, less than or equal to 4.5M, less than or equal to 4M, less than or equal to 3.5M, less than or equal to 3M, less than or equal to 2.5M, less than or equal to 2M, less than or equal to 1.5M, less than or equal to 1M, less than or equal to 0.5M, or less. Combinations of the ranges listed above are also possible (e.g., a concentration of the ionic salt, hydroxide, and / or acid in solution greater than or equal to 0.1 M and less than or equal to the solubility limit of the ionic salt, hydroxide, and / or acid in solution, a concentration of the ionic salt, hydroxide, and / or acid in solution greater than or equal to 4 M and less than or equal to 6 M).Other ranges are also possible.

[0048] As described herein, the aluminum may be activated with an activating composition that, in some embodiments, may penetrate into the grain boundaries and / or subgrain boundaries of the aluminum and break down the oxide layer that forms on the aluminum, thereby facilitating the reaction between the aluminum and water.

[0049] The activating composition may include any of a variety of suitable materials. In some embodiments, for example, the activating composition includes gallium and / or indium. Without wishing to be bound by theory, the gallium and / or indium may infiltrate through one or more grain boundaries and / or subgrain boundaries of the aluminum. The activating composition may be a eutectic composition or near a eutectic composition, including, for example, a eutectic composition of gallium and indium. In one such embodiment, the activating composition may include gallium and indium, and some of the activating compositions may have a composition of about 70% to 80% gallium and 20% to 30% indium by weight, although other weight percentages are also possible.

[0050] In some embodiments, the activator composition may be incorporated into an alloy with aluminum. The metal alloy may include any of the activator compositions in any of a variety of suitable amounts. In some embodiments, for example, the metal alloy includes greater than or equal to 0.1 wt. % of the activator composition, greater than or equal to 1 wt. % of the activator composition, greater than or equal to 5 wt. % of the activator composition, greater than or equal to 15 wt. % of the activator composition, greater than or equal to 30 wt. % of the activator composition, or greater than or equal to 45 wt. % of the activator composition, based on the total weight of the metal alloy. In some embodiments, the metal alloy includes less than or equal to 50 wt. % of the activator composition, less than or equal to 40 wt. % of the activator composition, less than or equal to 30 wt. % of the activator composition, less than or equal to 20 wt. % of the activator composition, less than or equal to 10 wt. % of the activator composition, less than or equal to 5 wt. % of the activator composition, based on the total weight of the metal alloy. Combinations of the above listed ranges are also possible (e.g., the metal alloy comprises greater than or equal to 0.1 wt.% and less than or equal to 50 wt.% of the activator composition based on the total weight of the metal alloy, the metal alloy comprises greater than or equal to 1 wt.% and less than or equal to 10 wt.% of the activator composition based on the total weight of the metal alloy), and other ranges are also possible.

[0051] The active aluminum may be provided in any desired form. In some embodiments, for example, the active aluminum is provided as a slurry, including a plurality of active aluminum particles dispersed within the slurry. In other embodiments, the active aluminum is provided as a plurality of active aluminum particles in a solid form (e.g., as a powder). The active aluminum particles may be regularly shaped, such as spheres, or may be irregularly shaped chunks. The size of the active aluminum particles may be uniform or may vary. Alternatively, the active aluminum particles may be provided in a more continuous form, such as a powder, with any suitable size distribution for the desired application.

[0052] The active aluminum particles may have any of a variety of suitable maximum characteristic dimensions (e.g., diameter, length, height, width). In some embodiments, for example, the active aluminum particles have an average maximum characteristic dimension of less than or equal to 100 micrometers, less than or equal to 90 micrometers, less than or equal to 80 micrometers, less than or equal to 70 micrometers, less than or equal to 60 micrometers, less than or equal to 50 micrometers, less than or equal to 40 micrometers, less than or equal to 30 micrometers, less than or equal to 20 micrometers, or less than that. In some embodiments, the active aluminum particles have an average maximum characteristic dimension of more than or equal to 10 micrometers, more than or equal to 20 micrometers, more than or equal to 30 micrometers, more than or equal to 40 micrometers, more than or equal to 50 micrometers, more than or equal to 60 micrometers, more than or equal to 70 micrometers, more than or equal to 80 micrometers, more than or equal to 90 micrometers, or more than that. Combinations of the above-listed ranges are also possible (e.g., the active aluminum particles have an average maximum characteristic dimension between less than or equal to 100 micrometers and greater than or equal to 10 micrometers, and the active aluminum particles have an average maximum characteristic dimension between less than or equal to 60 micrometers and greater than or equal to 40 micrometers). Other ranges are also possible.

[0053] In some embodiments where the active aluminum is provided as a slurry, a plurality of active aluminum particles may be suspended in any suitable carrier fluid. In some cases, for example, the carrier fluid may be a shear thinning fluid, although the present disclosure is not limited to using only shear thinning fluids. As used herein, the phrase "shear thinning fluid" is given its ordinary meaning in the art and generally refers to a fluid whose viscosity decreases under shear strain. Any of a variety of suitable shear thinning fluids may be utilized. In some embodiments, for example, the carrier fluid may include an oil, such as mineral oil, canola oil, and / or olive oil. In some embodiments, the carrier fluid may include a grease, alcohol, or other suitable material that is capable of suspending the water-reactive particles in the carrier fluid. In some embodiments, the carrier fluid includes a fumed silica thickener or other suitable thickener.

[0054] It should be understood that the slurry may have any suitable weight ratio of active aluminum particles to carrier fluid. Furthermore, without wishing to be bound by theory, the ratio of active aluminum particles to carrier fluid in the slurry may affect the physical properties of the slurry. For example, a slurry having a weight ratio of active aluminum particles to fluid carrier of 90:10 may be characterized as a paste, while a slurry with a ratio of 50:50 may flow more easily. In some applications, a ratio of active aluminum particles to fluid carrier as low as 10:90 may be desirable. Thus, the weight ratio of active aluminum particles to fluid carrier may be about 10:90 to 90:10 or equal thereto, although other suitable ranges both above and below those set forth above are also contemplated. In some embodiments, the slurry may be produced in a colloid mill, although other methods of producing the slurry using any suitable milling and / or mixing process are also contemplated, as the present disclosure is not limited in this respect.

[0055] In some embodiments, the use of slurries as liquid fuel sources offers significant advantages compared to solid fuel sources (e.g., bulk aluminum metal), including higher fill fractions, ease of storage (e.g., in articles and / or containers with complex geometries), ability to pump to liquid fuel sources with low losses, and / or higher storage stability. In certain embodiments, slurries can react with water almost instantly due to the higher surface area contact between the water and the water-reactive particles dispersed with the carrier fluid, thus providing higher reaction rates (compared to the use of solid fuel sources) and controlled hydrogen flow rates. The reaction between a liquid fuel source and water can also be stopped quickly by simply preventing the two reactant streams from mixing with each other.

[0056] Turning now to the figures, specific non-limiting embodiments will be described in further detail. It will be understood that the various systems, components, features, and methods described for these embodiments can be used either individually and / or in any desired combination, as the disclosure is not limited to only the specific embodiments described herein.

[0057] FIG 1A shows a schematic top view of a system 100 including a first reservoir 102, a second reservoir 104, and a reaction chamber 106, according to an embodiment. FIG 1B shows a schematic side view of the system of FIG 1A. As shown in FIGS 1A-1B, the system 100 may include a connection 101 (e.g., a connection 101a connecting the first reservoir 102 and the reaction chamber 106, and a connection 101b connecting the second reservoir 104 and the reaction chamber 106).

[0058] According to some embodiments, the first reservoir 102 is configured to contain an active aluminum composition. In some embodiments, the active aluminum composition includes aluminum and an activating composition as described herein. The active aluminum composition, in some embodiments, may include a slurry including a plurality of active aluminum particles dispersed within the slurry.

[0059] In some embodiments, the first reservoir 102 is configured to dispense the active aluminum composition into the reaction chamber 106. In an embodiment, for example, the active aluminum composition may flow from the first reservoir 102 into the reaction chamber 106 via connection 101a. Depending on the form in which the active aluminum is provided, connection 101a and / or any of the other connections described herein may comprise one or more valves, dampers, pumps, other hydraulic devices, conveyors, scoop-based dispensing systems, and / or any other suitable type of construction capable of dispensing a desired amount of material contained in the first reservoir or chamber to another reservoir or chamber of the system.

[0060] In an embodiment, the second reservoir 104 is configured to contain an ionic salt, hydroxide, and / or acid. The second reservoir 104 may, in some embodiments, be configured to contain a solution including water and an ionic salt, hydroxide, and / or acid dissolved and / or suspended in the water. In some embodiments, for example, the solution including water and ionic salt may be concentrated seawater. As will be discussed in more detail below, the second reservoir 104 may be configured to contain an ionic salt, hydroxide, and / or acid in solid form (e.g., as a powder), and the solid material may be hydrated within the second reservoir 104 and / or within the reaction chamber 106.

[0061] The second reservoir 104 may be configured to dispense ionic salts, hydroxides, and / or acids into the reaction chamber 106 in some embodiments. In an embodiment, for example, ionic salts, hydroxides, and / or acids (e.g., a solution including water and ionic salts, hydroxides, and / or acids dissolved and / or suspended in the water) may flow from the second reservoir 104 into the reaction chamber 106 via connection 101b. In other embodiments, the ionic salts, hydroxides, and / or acids may be dispensed from the second reservoir 104 into the reaction chamber 106 in solid form (e.g., as a powder). According to an embodiment, water to be used to react with the activated aluminum may be dispensed from the second reservoir 104 as a solution containing ionic salts, hydroxides, and / or acids present in the reaction chamber and / or in any desired concentration.

[0062] Figure 2A shows a schematic top view of a system 200 including a first reservoir 102, a second reservoir 104, a third reservoir 105, and a reaction chamber 106, according to an embodiment. Figure 2B shows a schematic side view of the system of Figure 2A. The first reservoir 102, the second reservoir 104, and the reaction chamber 106 may be configured as described above with respect to Figures 1A-1B. The connections 101 as shown in Figures 2A-2B (e.g., connection 101a connecting the first reservoir 102 and the reaction chamber 106, connection 101b connecting the second reservoir 104 and the reaction chamber 106, connection 101c connecting the third reservoir 105 and the reaction chamber 106, and connection 101f connecting the third reservoir 105 and the second reservoir 104) may be any of the connections described above.

[0063] In certain embodiments, the system includes a third reservoir 105, which may be configured to contain a separate volume of water to be used to react with the activated aluminum.

[0064] The third reservoir 105, in some embodiments, may be configured to dispense water into the reaction chamber 106. For example, in an embodiment, water may flow from the third reservoir 105 into the reaction chamber 106 via connection 101c. In some embodiments, the water dispensed from the third reservoir 105 into the reaction chamber 106 may be dispensed into the reaction chamber 106 from the second reservoir 104 in addition to water from a solution that includes water and ionic salts, hydroxides, and / or acids dissolved and / or suspended in the water.

[0065] According to some embodiments, the third reservoir 105 may also be configured to dispense water into the second reservoir 104. In certain embodiments, for example, water may flow from the third reservoir 105 into the second reservoir 104 via connection 101f. In some such embodiments, the water may dissolve ionic salts, hydroxides, and / or acids in solid form contained within the second reservoir 104. However, embodiments are also envisioned in which a separate water source is used to provide water to the second reservoir.

[0066] It should be understood that in the various embodiments described herein, the first reservoir 102, the second reservoir 104, and / or the third reservoir 105 may have any of a variety of suitable shapes, sizes, and / or volumes depending on the desired application.

[0067] 1A-1B, the system 100 includes a reaction chamber 106. As discussed above, the reaction chamber 106 is in fluid communication with a first reservoir 102 (e.g., via connection 101a) and a second reservoir 104 (e.g., via connection 101b). As shown in FIGs. 2A-2B, the reaction chamber 106 is in fluid communication with a third reservoir 105 (e.g., via connection 101c).

[0068] Regardless of the specific construction for providing materials to the reaction chamber 106, the reaction chamber 106 may be configured such that an active aluminum composition (e.g., dispensed from the first reservoir 102) reacts with water in the presence of an ionic salt, hydroxide, and / or acid (e.g., dispensed from the second reservoir 104) within the reaction chamber 106 to produce hydrogen gas and one or more reaction products.

[0069] According to some embodiments, the amount of ionic salt, hydroxide, and / or acid dispensed from the second reservoir 104 into the reaction chamber 106 is at least an amount sufficient to cause the activated composition to form a separate phase after the activated aluminum composition reacts with water in the reaction chamber 106. While not wishing to be bound by theory, it is believed that the ionic cations (e.g., Na, NaCl ... + ) and / or ionic anions (e.g., Cl -) may adhere and / or otherwise aggregate on the surface of the activating composition as the activating composition activates the aluminum. In some embodiments, the adhesion and / or aggregation of the ionic cations and / or ionic anions prevents the components of the activating composition from dissociating or oxidizing, causing the activating composition to form one or more separate phases after the aluminum is consumed by reaction with water. According to some embodiments, the activating composition may form one or more macro-sized beads of material that may undergo further separation from one or more additional materials. For example, with reference to FIG. 1B, after the activated aluminum composition reacts with water, the reaction chamber 106 may include a separate phase of the activating composition 152 and the additional phase 150. Additional phase 150, in some embodiments, may include one or more of the following components: one or more reaction products (e.g., AlO(OH), Al(OH) as shown in reactions (1) and (2)), unreacted water, and / or excess and / or residual ionic salts, hydroxides, and / or acids (e.g., dissolved and / or suspended in water).

[0070] In certain embodiments, a separate phase of the activating composition 152 may advantageously flow downward to the bottom of the reaction chamber 106 relative to the direction of gravity 175. Without wishing to be bound by theory, the molecular weight of one or more components of the separate phase of the activating composition 152 (e.g., gallium and / or indium) exceeds the molecular weight of each of the components of the additional phase 150. Thus, a separate phase of the activating composition 152 that is heavier than the additional phase 150 is advantageously readily separable from the additional phase 150.

[0071] FIG. 3A shows a schematic top view of a system 300 including a first reservoir 102, a second reservoir 104, a reaction chamber 106, and a separation system 108 according to an embodiment. FIG. 3B shows a schematic side view of the system of FIG. 3A. The first reservoir 102, the second reservoir 104, and the reaction chamber 106 may be configured as described above with respect to FIGS. 1A-1B. The connections 101 shown in FIGS. 3A-3B (e.g., connection 101a connecting the first reservoir 102 and the reaction chamber 106, connection 101b connecting the second reservoir 104 and the reaction chamber 106, and connection 101d connecting the reaction chamber 106 and the separation system 108) may be any of the connections described above.

[0072] As described herein, the separation system 108 may comprise any of a variety of suitable separation mechanisms. In some embodiments, for example, as shown in FIG. 3B, the separation system 108 comprises a gravity-based separation system. For example, referring to FIG. 3B, the separated phase of the activation composition 152 may be separated from the additional phase 150 by flowing into the separation system 108 through the connection 101d in a downward direction relative to gravity 175. In some embodiments, the outlet port of the reaction chamber 106 leading to the connection 101d may be located on a portion of the reaction chamber 106 below a height where the reactants and / or reaction products are expected to be located after and / or during the reaction. In some embodiments, the inlet port of the separation system 108 leading from the connection 101d may be correspondingly located at or below a similar height at or below a threshold height for separation of the separated phase of the activation composition 152. According to some embodiments, the separation system 108 may be located below the reaction chamber 106 in a downward direction relative to gravity 175. As discussed herein, other separation systems, such as a separation funnel-based system or the application of an external electric field may also be employed, as the disclosure is not intended to be limiting in this respect.

[0073] FIG. 4A shows a schematic top view of a system including a first reservoir 102, a second reservoir 104, one or more processors 110, a reaction chamber 106, and a separation system 108 according to an embodiment. FIG. 4B shows a schematic side view of the system of FIG. 4A. The first reservoir 102, the second reservoir 104, and the reaction chamber 106 may be configured as described above with respect to FIGS. 1A-1B. The separation system 108 may be configured as described above with respect to FIGS. 3A-3B. The connections 101 shown in FIGS. 4A-4B (e.g., connection 101a connecting the first reservoir 102 and the reaction chamber 106, connection 101b connecting the second reservoir 104 and the reaction chamber 106, and connection 101d connecting the reaction chamber 106 and the separation system 108) may be any of the connections described above.

[0074] In some embodiments, one or more processors (e.g., processor 110a and processor 110b) are associated with corresponding memory that includes processor-executable instructions that, when executed, are configured to control the amount of active aluminum composition from first reservoir 102, and / or the amount of ionic salt, hydroxide, and / or acid (e.g., a solution comprising water and ionic salt, hydroxide, and / or acid dissolved and / or suspended in water) from second reservoir 104, and any other suitable material from any other reservoir of the system, that enters reaction chamber 106. In an embodiment, the one or more processors may control the flow rates of materials in addition to the amounts of materials that enter the reaction chamber from their respective reservoirs.

[0075] Depending on the embodiment, the one or more processors may be configured to control any suitable dispensing system to dispense materials from corresponding reservoirs to the reaction chambers, including, for example, one or more pumps (e.g., vacuum pumps), valves, conveyor systems, and / or any other suitable dispensing system, as described above.

[0076] 4A and 4B, processor 110a may be associated with first reservoir 102 (e.g., to control the amount and / or flow rate of active aluminum composition entering reaction chamber 106) and processor 110b may be associated with second reservoir 104 (e.g., to control the amount and / or flow rate of ionic salt, hydroxide, and / or acid entering reaction chamber 106). Although not shown in the figures, a processor may also be associated with third reservoir 105, for example, to control the amount and / or flow rate of water entering reaction chamber 106 from third reservoir 105.

[0077] FIG. 5A shows a schematic top view of a system including a first reservoir 102, a second reservoir 104, one or more processors 110, a reaction chamber 106, a separation system 108, and a collection chamber 112, according to an embodiment. FIG. 5B shows a schematic side view of the system of FIG. 5A. The first reservoir 102, the second reservoir 104, and the reaction chamber 106 may be configured as described above with respect to FIGS. 1A-1B. The separation system 108 may be configured as described above with respect to FIGS. 3A-3B. The one or more processors 110 may be configured as described above with respect to FIGS. 4A-4B. The connections 101 as shown in Figures 5A-5B (e.g., connection 101a connecting the first reservoir 102 and the reaction chamber 106, connection 101b connecting the second reservoir 104 and the reaction chamber 106, connection 101d connecting the reaction chamber 106 and the separation system 108, connection 101e connecting the separation system 108 and the collection chamber 112, and connection 101g connecting the collection chamber 112 and the first reservoir 102) may be any of the connections described above.

[0078] In some embodiments, the collection chamber 112 is configured to receive a separate phase of the activating composition 152 from the reaction chamber 106. In certain embodiments, the separate phase of the activating composition 152, which has been separated from the other phase 150 via the separation system 108, may flow into the collection chamber 112 from the separation system 108 via connection 101e, as shown in FIG. 5B. After recovering the separate phase of the activating composition 152, the activating composition, in some embodiments, may be recycled to the first reservoir 102 via connection 101g and used to activate more aluminum for a subsequent reaction between the activated aluminum and water.

[0079] Collection chamber 112 may also be configured in some embodiments to receive one or more components of additional phase 150 (e.g., one or more reaction products, ionic salts, hydroxides, and / or acids). Although not shown in the figures, the system may include multiple collection chambers, each configured to receive a separate material, e.g., a first collection chamber configured to receive a separate phase of activation composition 152, a second collection chamber configured to receive one or more reaction products (e.g., AlO(OH), Al(OH)3 as shown in reactions (1) and (2)), and a third collection chamber configured to receive excess and / or residual ionic salts, hydroxides, and / or acids (e.g., dissolved and / or suspended in water).

[0080] The following examples are intended to illustrate certain embodiments of the present disclosure, but do not exemplify the complete scope of the disclosure.

[0081] Working Example Example 1 The following examples illustrate the effectiveness of adding various ionic salts, hydroxides, and / or acids to the aluminum-water reaction environment to enable mechanical recovery of activated gallium-indium alloy as a liquid metal alloy. Various ionic aqueous solutions were prepared by dissolving salts, including NaCl, KCl, CaCl2, MgCl2, and NaHCO3, in 0.2M increments at molar concentrations ranging from 0.1M to 5M, in pre-deionized water. Each solution was prepared to contain a single salt species. For each combination of ionic salt and concentration, 0.3 g of gallium-indium-activated aluminum was reacted in 10 mL of solution in a 100 mL Erlenmeyer flask. The top opening of the flask was covered except for a small opening of 3 mm diameter to allow hydrogen to escape while also slowing down the rate of water evaporation in the flask. All reactions were carried out at an initial temperature and pressure of 20°C and 1 atm, respectively. In all combinations of salts and concentrations listed above, liquid gallium-indium was observed to emerge from solution at the bottom of each flask. In each case, the liquid metal alloy was collected after completion of the aluminum-water reaction, immersed in deionized water for a minimum of 48 hours, dried, and weighed. For each trial, the amount of eutectic collected was compared to the initial mass of treated aluminum, whose aluminum content was known, allowing the calculation of the gallium-indium recovery fraction. In all cases, the calculated recovery fraction was within an error bar of (±0.05) of 1 (i.e., complete recovery of the activated compound).

[0082] In one trial, 3 g of activated aluminum was reacted in 20 mL of 3.9 M NaCl solution under conditions otherwise similar to the experiments listed above. After 48 hours, the liquid metal was physically separated from the bulk solution using a syringe and immersed in deionized water for an additional 48 hours. The liquid metal was dried and weighed, and the final reported mass was 0.247 g versus the expected 0.248 g, resulting in a recovery fraction of 0.996 ± 0.008.

[0083] The validity of the present approach was also demonstrated in ionic solutions with an initial pH not equal to 7. First, 10 mL of 0.1 M NaOH solution (pH 13) was prepared and reacted with 0.3 g of activated aluminum in a 100 mL Erlenmeyer flask under conditions otherwise similar to the experiment discussed above. As shown in FIG. 7, as the reaction went to completion, liquid metal emerged from the reaction product and coalesced into mechanically separable beads whose final mass and recovery ratio were measured to be within an error bar of (±0.05) relative to 1. A similar experiment was performed using a 1 M HCl solution (pH 0), again resulting in complete recovery of activated gallium and indium as mechanically separable liquid metal alloys, i.e., within an error bar of (±0.05).

[0084] In separate trials, the amount of hydrogen was measured for reactions involving NaOH solutions at various concentrations. The aluminum-water reactions in these cases were carried out in an enclosed reaction chamber so that the reaction was completed isobarically (i.e., at constant volume). The pressure and temperature in the chamber were measured throughout the reaction and used to calculate the amount of hydrogen present in the chamber. In one set of trials, the volume of the reaction solution was held constant at 5 mL, and the mass of reacted active aluminum was held constant at 0.9 g as well. Only the ionic strength of the input aqueous solution, and therefore the pH, was varied by varying the concentration of NaOH. As shown in FIG. 6, increasing the ionic strength has the added benefit of increasing the amount of hydrogen produced for the same volume of water. The degree of reactivity is obtained as the ratio of hydrogen measured from the reaction divided by the theoretical stoichiometric hydrogen yield for the amount of aluminum brought into the reaction chamber. NaOH can be regenerated from the system utilizing this observed phenomenon using the process outlined in FIG. 8.

[0085] The importance of ionic strength in gallium-indium alloy recovery has been demonstrated by comparing the reaction products in ionic aqueous solutions with non-ionic aqueous solutions of comparable solute concentration. Specifically, experiments were conducted in which 0.3 g of activated aluminum pellets were reacted with 10 mL of the following aqueous solutions individually: deionized water (pH 7), 3M glucose solution, 3M sucrose solution, 3M NaCl, and 3M KCl. In reactions with deionized water, 3M glucose solution, and 3M sucrose solution, all of which have ionic strength equal to 0 due to the absence of dissociation of the solute into ions, no liquid gallium-indium alloy was observed or could be extracted after the reaction was completed. In reactions with 3M NaCl solution and 3M KCl solution, both with ionic strength equal to 3M, liquid gallium-indium alloy was recovered at a recovery fraction equal to 1 within an error bar of (±0.05).

[0086] Finally, it has been shown that under non-ionic initial reaction conditions (i.e., active aluminum was initially reacted with deionized water at pH 7), indium can dealloy from the initial gallium-indium alloy over the course of the reaction, inducing the formation of solid indium aggregates with average characteristic diameters ranging from 0.1 to 10 micrometers. FIG. 10A shows an SEM image of the aggregates, and FIG. 10B shows a ZAF-corrected EDS atomic map of the same sample, showing its high indium concentration. These indium aggregates have limited mobility in the bulk reaction product, making them difficult to separate using mechanical means. The methods discussed herein prevent this dealloying from occurring, allowing the gallium-indium alloy to remain liquid throughout the reaction, and therefore easily separable, once the reaction is complete. FIG. 9A shows an SEM image of the by-products of the active aluminum-water reaction in a NaOH solution with an ionic strength of 0.1 M, showing the presence of the gallium-indium alloy in the liquid phase. The ZAF-corrected EDS atomic map of the same sample in FIG. 9B shows the presence of gallium and indium within the liquid condensate in a ratio consistent with the original composition of the gallium-indium alloy used to initially process the aluminum sample.

[0087] The embodiments described herein may be embodied as methods, of which examples are provided. The acts performed as part of the method may be ordered in any suitable manner. Thus, although shown as sequential acts in the illustrative embodiments, embodiments may be constructed in which acts are performed in an order different from that shown, which may include performing certain acts simultaneously.

[0088] Additionally, some actions are described as being taken by a "user." It should be understood that a "user" need not be a single individual, and that in some embodiments, actions attributed to a "user" may be performed by a team of individuals and / or an individual in combination with computer-assisted tools or other mechanisms.

[0089] Although several embodiments of the present disclosure have been described and illustrated herein, those skilled in the art will readily envision various other means and / or structures for performing the functions and / or obtaining one or more of the results and / or advantages described herein, and each such variation and / or modification is deemed to be within the scope of the present disclosure. More generally, those skilled in the art will readily appreciate that all parameters, dimensions, materials, and configurations described herein are intended to be exemplary, and that the actual parameters, dimensions, materials, and / or configurations will depend on the specific application or applications in which the teachings of the present disclosure are used. Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, many equivalents to the specific embodiments of the disclosure described herein. Thus, it is to be understood that the foregoing embodiments are presented by way of example only, and that, within the scope of the appended claims and their equivalents, the present disclosure may be practiced otherwise than as specifically described and claimed. The present disclosure is directed to each individual feature, system, article, material, and / or method described herein. In addition, any combination of two or more such features, systems, articles, materials, and / or methods is included within the scope of the present disclosure, if such features, systems, articles, materials, and / or methods are not mutually inconsistent.

[0090] The indefinite articles "a" and "an," as used herein in the specification and the claims, unless expressly indicated otherwise, should be understood to mean "at least one."

[0091] The phrase "and / or" as used herein in the specification and claims should be understood to mean "either or both" of the elements so conjoined, i.e., elements that are conjunctive in some cases and disjunctive in other cases. Unless expressly indicated otherwise, other elements may optionally be present other than the elements specifically identified by the "and / or" clause, whether related or unrelated to those elements specifically identified. Thus, as a non-limiting example, a reference to "A and / or B," when used in conjunction with open-ended language such as "comprising," can refer in one embodiment to A without B (optionally including elements other than B), in another embodiment to B without A (optionally including elements other than A), in yet another embodiment to both A and B (optionally including other elements), etc.

[0092] As used herein in the specification and claims, "or" should be understood to have the same meaning as "and / or" as defined above. For example, when separating items in a list, "or" or "and / or" shall be interpreted as being inclusive, i.e., the inclusion of at least one, but also more than one of some element or list of elements, optionally including additional unlisted items. Only terms clearly indicated to the contrary, such as "only one of" or "exactly one of," or, when used in the claims, "consisting of," will refer to the inclusion of exactly one element of some element or list of elements. In general, the term "or" as used herein, when preceded by a term of exclusivity, such as "either," "one of," "only one of," or "exactly one of," shall be interpreted as indicating only exclusive alternatives (i.e., "one or the other but not both"). "Consisting essentially of," when used in the claims, shall have its ordinary meaning as used in the field of patent law.

[0093] As used herein in the specification and claims, the phrase "at least one" in reference to a list of one or more elements should be understood to mean at least one element selected from any one or more of the elements in the list of elements, but not necessarily including at least one of each and every element specifically listed in the list of elements, and not excluding any combination of elements in the list of elements. This definition also allows for the optional presence of elements other than those specifically identified in the list of elements to which the phrase "at least one" refers, whether related or unrelated to those elements specifically identified. Thus, as a non-limiting example, "at least one of A and B" (or, equivalently, "at least one of A or B," or, equivalently, "at least one of A and / or B") can refer in one embodiment to at least one A, optionally including more than one A, in which B is absent (optionally including elements other than B), in another embodiment to at least one B, optionally including more than one B, in yet another embodiment to at least one A, optionally including more than one A, and at least one B, optionally including more than one B (optionally including other elements), etc.

[0094] In the claims and in the above specification, all transitional phrases such as "comprising," "including," "carrying," "having," "containing," "involving," "holding," and the like, are to be understood to be open-ended, i.e., to mean "including but not limited to." Only the transitional phrases "consisting of" and "consisting essentially of" shall be closed or semi-closed transitional phrases, respectively, as set forth in the United States Patent Office Manual of Patent Examining Procedures Section 2111.03.

Claims

**Claim 1** A method for producing hydrogen gas, comprising: reacting, in a reaction chamber, an activated aluminum composition comprising aluminum and an activating composition with a solution comprising water and at least one selected from the group consisting of an ionic salt, a hydroxide, and an acid to produce hydrogen gas and one or more reaction products; forming a separated phase comprising the activating composition after reacting the activated aluminum composition with the water; The method comprising the steps above. **Claim 2** (i) Prior to reacting, dispensing the activated aluminum composition from a first reservoir into the reaction chamber, and / or (ii) Prior to reacting, dispensing the ionic salt, the hydroxide, or the acid from a second reservoir into the reaction chamber, and / or (iii) Prior to reacting, dispensing the water from a third reservoir into the reaction chamber The method according to claim 1, further comprising the steps above. **Claim 3** The method according to any one of claims 1-2, wherein the activating composition comprises gallium and / or indium. **Claim 4** (i) The solution comprises the ionic salt, optionally the ionic salt comprises NaCl, KCl, NaHCO3, MgCl2, and / or CaCl2, and / or (ii) The solution comprises the hydroxide, optionally the hydroxide comprises NaOH, KOH, Ca(OH)2, and / or Mg(OH)2, and / or (iii) The solution comprises the acid, optionally the acid comprises HCl, H2SO4, and / or CH3COOH, The method according to claim 1. **Claim 5** The method according to claim 1, wherein the concentration of the ionic salt, the hydroxide, or the acid in the solution is between 0.1 M or more and below the solubility limit of the ionic salt, the hydroxide, or the acid in the solution. **Claim 6** The method according to claim 1, further comprising maintaining a wet activating composition after reacting the activated aluminum composition with the water. **Claim 7** The method according to claim 1, wherein forming the separated phase of the activating composition comprises separating the activating composition from one or more reaction products of the activated aluminum composition and the water. **Claim 8** The method according to claim 1, further comprising flowing the separation phase containing the activation composition from the reaction chamber to a recovery chamber.

9. A system comprising: a first reservoir configured to contain an activated aluminum composition comprising aluminum and an activation composition; a second reservoir configured to contain an ionic salt, a hydroxide, and / or an acid; a reaction chamber in fluid communication with the first reservoir and the second reservoir, wherein the first reservoir is configured to dispense the activated aluminum composition into the reaction chamber, the second reservoir is configured to dispense the ionic salt, the hydroxide, and / or the acid into the reaction chamber, and the reaction chamber is configured such that the activated aluminum composition reacts with water in the presence of the ionic salt, the hydroxide, and / or the acid in the reaction chamber to produce hydrogen gas and one or more reaction products. A system comprising the above.

10. The system according to claim 9, wherein the second reservoir is configured to dispense the ionic salt, the hydroxide, and / or the acid into the reaction chamber in an amount sufficient to form a separation phase in the activation composition after the activated aluminum composition has reacted with the water.

11. (i) a separation system configured to separate the activation composition from the one or more reaction products, and / or (ii) a recovery chamber in fluid communication with the reaction chamber, the recovery chamber being configured to receive the separation phase of the activation composition from the reaction chamber, and / or (iii) a third reservoir configured to contain the water, the third reservoir being configured to dispense the water into the reaction chamber. The system according to claim 10, further comprising the above.

12. The system according to any one of claims 9-11, wherein the ionic salt, the hydroxide, and / or the acid are dissolved in the water.

13. The system according to claim 9, wherein the activation composition comprises gallium and / or indium.

14. (i) the ionic salt disposed within the second reservoir, and / or (ii) the hydroxide disposed in the second reservoir, and / or, (iii) the acid disposed on the second reservoir The system according to claim 9, further comprising.

15. (i) The ionic salt includes NaCl, KCl, NaHCO ３ , MgCl ２ , and / or CaCl ２ , and / or (ii) the hydroxide includes NaOH, KOH, Ca(OH)₂, and / or Mg(OH)₂, and / or, (iii) the acid includes HCl, H₂SO₄, and / or CH₃COOH, The system according to claim 14. **Claim 16** The system according to claim 9, further comprising one or more processors configured to control the amounts of the activated aluminum composition, the ionic salt, the hydroxide, the acid, and / or the water entering the reaction chamber. **Claim 17** The concentration of the ionic salt, the hydroxide, and / or the acid dissolved in the water is between 0.1 M or more and below the solubility limit of the ionic salt, the hydroxide, and / or the acid in the water. The system according to claim 12. **Claim 18** A system, A first reservoir configured to contain an activated aluminum composition comprising aluminum and an activating composition; A second reservoir configured to contain a solution comprising water and an ionic salt, a hydroxide, and / or an acid dissolved in the water; A reaction chamber in fluid communication with the first reservoir and the second reservoir, wherein the first reservoir is configured to dispense the activated aluminum composition into the reaction chamber, the second reservoir is configured to dispense the solution into the reaction chamber, and the reaction chamber is configured such that the activated aluminum composition reacts with the water in the presence of the ionic salt, the hydroxide, and / or the acid to produce hydrogen gas and one or more reaction products, and the amounts of the ionic salt, the hydroxide, and / or the acid are sufficient to form a separate phase in the activating composition after the activated aluminum composition reacts with the water. A reaction chamber; A separation system configured to separate the activating composition from one or more reaction products; A recovery chamber in fluid communication with the reaction chamber, the recovery chamber being configured to receive the separate phase of the activating composition from the reaction chamber. A recovery chamber A system comprising... **Claim 19** The system according to claim 18, wherein the activating composition contains gallium and / or indium.

20. (i) The ionic salt is NaCl, KCl, NaHCO ３ , MgCl ２ , and / or CaCl ２ , and / or (ii) The hydroxide contains NaOH, KOH, Ca(OH)₂, and / or Mg(OH)₂, and / or (iii) The acid contains HCl, H₂SO₄, and / or CH₃COOH. The system according to any one of claims 18 - 19.

Images