Embodiments of the technology relate generally to a gas storage system comprising multiple gas storage chambers wherein each chamber comprises a metal alloy material.
Hydrogen is the object of significant research as an alternate fuel source to fossil fuels. Hydrogen is attractive because (i) it can be produced from many diverse energy sources, (ii) it has a high energy content by weight (about three times more than gasoline) and (iii) it has a zero-carbon emission footprint—the by-products of hydrogen combustion being oxygen and water.
However, hydrogen has physical characteristics that make it difficult to store in large quantities without taking up a significant amount of space. Despite hydrogen's high energy content by weight, hydrogen has a low energy content by volume. This makes hydrogen difficult to store, particularly within the size and weight constraints of a vehicle, for example. Another major obstacle is hydrogen's flammability and the concomitant safe storage thereof.
Known hydrogen storage technologies directed to high pressure tanks with compressed hydrogen gas and/or cryogenic liquid hydrogen storage have shortcomings because the risk of explosion still exists. These approaches require pressurized containers that are heavy and also require high energy input-features that detract from commercial viability.
Metal alloy hydrogen storage is based on materials capable of reversibly absorbing and releasing the hydrogen. Metal alloy hydrogen storage provides high energy content by volume, reduces the risk of explosion, and eliminates the need for high pressure tanks and insulation devices. Metal alloy hydrogen storage, however, struggles with low energy content by weight.
Examples of hydrogen storage devices using metal alloys are described in U.S. Pat. No. 9,841,147 to Kernene. However, additional advancements for improving the quantity and efficiency with which hydrogen is stored in a metal alloy storage device would be beneficial. In particular, storage devices that improve the energy density and facilitate use of the stored hydrogen in a variety of applications would be useful. Additionally, modular systems for storing hydrogen gas so that the modular systems can be deployed in vehicles, in portable generators, and energy storage systems would be desirable. Accordingly, examples of improved hydrogen storage systems and implementations are described herein. While the examples described herein primarily relate to the storage of hydrogen, it should be understood that the storage systems disclosed herein can be used to store other gases as well.
The present disclosure is generally directed to an improved gas storage unit for storing hydrogen as well as other gases. In one example embodiment, the gas storage unit can comprise a cylindrical container with first and second end anvils enclosing the cylindrical container. An intermediate anvil can be disposed within the cylindrical container between the first and second end anvils. A first gas storage chamber can be disposed within the cylindrical container and between the first end anvil and the intermediate anvil. The first gas storage chamber can comprise a first cylindrical diaphragm and a first metal alloy material disposed in a first annulus between the first cylindrical diaphragm and an inner surface of the cylindrical container. Similarly, the second gas storage chamber can comprise a second cylindrical diaphragm and a second metal alloy material disposed in a second annulus between the second cylindrical diaphragm and an inner surface of the cylindrical container.
The foregoing example embodiment of a gas storage unit can comprise one or more of the following example features. In one example, hydrogen gas can be stored in the first metal alloy material of the first gas storage chamber and in the second metal alloy material of the second gas storage chamber. The first gas storage chamber can be in fluid communication with the second gas storage chamber via a first anvil channel passing through the intermediate anvil. The gas storage unit can further comprise a spacer disk disposed between the first gas storage chamber and the second gas storage chamber. The first diaphragm can comprise a flange disposed between a raised inner flange of the spacer disk and the intermediate anvil
In the foregoing example embodiment, the intermediate anvil can be disposed between the spacer disk and a second spacer disk. The intermediate anvil can comprise an equatorial portion disposed between a raised flange of the spacer disk and a raised flange of the second spacer disk. The intermediate anvil can comprise a first side disposed within the first gas storage chamber and a second side disposed within the second gas storage chamber, wherein the first side and the second side of the intermediate anvil each have a truncated conical shape. The equatorial portion of the intermediate anvil can comprise radial channels extending from the intermediate anvil channel to a perimeter of the equatorial portion. Hydrogen gas can pass through the radial channels for storage in and release from the first metal alloy and the second metal alloy.
In the foregoing example embodiment, hydrogen gas can pass through the first cylindrical diaphragm for storage in and release from the first metal alloy and passes through the second cylindrical diaphragm for storage in and release from the second metal alloy.
In the foregoing example embodiment, the inner surface of the cylindrical container can comprise flutes and the spacer disk can comprise a perimeter having protrusions, wherein the protrusions of the spacer disk fit within the flutes of the inner surface of the cylindrical container.
In the foregoing example embodiment, the gas storage unit can be coupled to at least one other gas storage unit along a longitudinal axis of the gas storage unit.
In another example embodiment, the present disclosure is directed to a hydrogen storage assembly comprising a first hydrogen storage unit in fluid communication with a second hydrogen storage unit. The first hydrogen storage unit and the second hydrogen storage unit can each comprise the features of the gas storage unit described in the preceding paragraphs.
In the foregoing example of a hydrogen storage assembly, the hydrogen storage assembly can have a capacity of 6-42 kg of hydrogen and 203-1415 kWh of power. In another example, the hydrogen storage assembly can have a capacity of 3,000-4,500 kg of hydrogen and 100-200 MWh of power. In the foregoing example, the hydrogen storage assembly can be disposed in a shipping container. In the foregoing example, the first hydrogen storage unit and the second hydrogen storage unit can be coupled in series.
In yet another example embodiment, the present disclosure is directed to a hydrogen-powered generator comprising: a fuel cell; a power converter; and a hydrogen storage assembly comprising a first hydrogen storage unit in fluid communication with a second hydrogen storage unit. The first hydrogen storage unit and the second hydrogen storage unit can each comprise the features of the previously described gas storage unit.
The foregoing embodiments are non-limiting examples and other aspects and embodiments will be described herein. The foregoing summary is provided to introduce various concepts in a simplified form that are further described below in the detailed description. This summary is not intended to identify required or essential features of the claimed subject matter nor is the summary intended to limit the scope of the claimed subject matter.
The accompanying drawings illustrate only example embodiments of gas storage systems and therefore are not to be considered limiting of the scope of this disclosure. The principles illustrated in the example embodiments of the drawings can be applied to alternate methods and apparatus for a gas storage system. Additionally, the elements and features shown in the drawings are not necessarily to scale, emphasis instead being placed upon clearly illustrating the principles of the example embodiments. Certain dimensions or positions may be exaggerated to help visually convey such principles. In the drawings, the same reference numerals used in different embodiments designate like or corresponding, but not necessarily identical, elements.
The example embodiments discussed herein are directed to a gas storage unit for storing hydrogen as well as other gases with improved efficiency and adaptability. The example embodiments described herein optimize the storage of hydrogen gas in a plurality of storage chambers within a gas storage unit. The hydrogen is adsorbed and/or absorbed by the metal alloys producing a metal hydride that can be stored in the storage units described herein. The metal hydride stored within the gas storage units is very stable allowing it to be easily transported and stored for several years with very little hydrogen loss. The hydrogen storage unit also is optimized to maximize the quantity of hydrogen stored within the volume of the unit. The hydrogen storage unit can be easily combined with multiple hydrogen storage units into an assembly. The configuration of the hydrogen storage unit facilitates the use of hydrogen as a fuel source, for example, in a vehicle, in a generator as a primary or backup power supply, or as a power source that can be used in remote locations lacking an electrical grid. As will be described further in the following examples, the methods and apparatus described herein improve upon prior approaches to storing hydrogen.
While the example embodiments described herein are directed to storage units for hydrogen gas, it should be understood that the storage units described herein can also be used to store other types of gases. Examples of gasses that can be stored in the storage units described herein include hydrogen, methane, ethane, propane, butane, hythane (hydrogen/methane), and combinations thereof.
In the following paragraphs, particular embodiments will be described in further detail by way of example with reference to the drawings. In the description, well-known components, methods, and/or processing techniques are omitted or briefly described. Furthermore, reference to various feature(s) of the embodiments is not to suggest that all embodiments must include the referenced feature(s).
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The metal alloy 122 is of a type that can absorb hydrogen gas to form a metallic hydride. The metal alloy can comprise any combination of the following materials: nickel, tin, aluminum, manganese, iron, cobalt, copper, titanium, antimony, and rare earth metals such as yttrium, lanthanum, cerium, prascodymium, and neodymium. The metal alloy is typically a granular material that forms a porous composition and may include a binding agent. The metal alloy granules can have a D50 particle size from 1.0 microns, or 1.5 microns, or 2.0 microns to 2.5 microns, or 3.0 microns, or 4.0 microns, or 5.0 microns. In one example, the D50 particle size of the metal alloy granules ranges from 1.5 microns to 2.0 microns. The term “D50” refers to the median diameter of the metal alloy granules such that 50% of the sample weight is above the stated particle diameter.
With each charging and discharging of the gas storage unit, hydrogen can flow between the coupler 105 and the metal alloy 122. Taking the charging of the gas storage unit 100 as an example, the hydrogen gas can enter the cylindrical container 101 through coupler 105 and through an end anvil channel in the end anvil 102, pass into the diaphragm chamber 121, and pass through the anvil channel of each intermediate anvil to flow into the next diaphragm chamber of the second, third, and fourth chambers. The flow of hydrogen between the diaphragm chambers and the metal alloy can take one or more paths depending upon the particular embodiment of the gas storage unit 100.
In one example embodiment, each diaphragm comprises a semi-permeable material that retains the metal alloy in the metal alloy chamber while permitting gaseous hydrogen to pass through the diaphragm and back and forth between the diaphragm chamber and the metal alloy chamber during charging and discharging of the gas storage unit 100. The hydrogen gas passes from the inner portion of the chamber through the semi-permeable membrane of each diaphragm and is stored in the metal alloy material in the outer portion of each chamber. Examples of the semi-permeable material of the diaphragm include, but are not limited to, polymeric materials such as polyethylene and polypropylene, as well as composite materials.
In another example embodiment, the hydrogen gas can pass between the diaphragm chambers and the metal alloy chambers via one or more radial channels 127 located in the intermediate anvils. As illustrated in
In yet another example embodiment, the intermediate anvils and spacer disks can include one or more ports permitting the flow of hydrogen between the diaphragm chamber and the metal alloy chamber. Moreover, other example embodiments can include combinations of the foregoing examples, such as an embodiment that includes both a hydrogen permeable membrane and radial channels in the intermediate anvils so that there is more than one path for the hydrogen to flow within each chamber.
When absorbed by the metal alloy material, the hydrogen gas can be stored in a stable and secure manner. When discharging hydrogen from the gas storage unit 100, the hydrogen gas flows from the metal alloy material in each chamber, through one of the previously described paths and into the diaphragm chamber from which it can exit through the channels passing through each anvil.
Referring to the first gas storage chamber 112, the diaphragm 120 is held in place between the end anvil 102 and the first intermediate anvil 128. The first disk spacer 124 is placed on the inner surface of the end anvil 102 and further secures one end of the diaphragm 120. At the opposite end of the first gas storage chamber 112, a second disk spacer 125 is co-axial with and surrounds the first intermediate anvil 128, securing the opposite end of the diaphragm 120. Each of the second chamber 113, the third chamber 114, and fourth chamber 115 has a similar arrangement to the first gas storage chamber 112.
Examples of suitable materials for the cylindrical container 101, the end anvils 102, 103, the intermediate anvils 128, and the spacer disks 124, 125, 126 include metals, polymeric materials, nanomaterials, and combinations thereof. Examples of suitable metals include aluminum, aluminum alloys, copper, steel, and combinations thereof. Examples of suitable polymeric material for the cylinder include carbon fiber, polyolefin, polycarbonate, acrylate, fiberglass, Ultem, and combinations thereof. The cylindrical container and its components may be a combination of metal and polymeric material such as a metal liner thermoset in a polymeric resin, for example.
In an embodiment, the cylindrical container 101 is composed of a heat conductive material. The metal alloy is packed against the inner surface of the cylindrical container 101 to facilitate the exchange of heat. The heat conductive material promotes heat dissipation (cooling) during charging of the gas storage unit with hydrogen and promotes warming during discharging of hydrogen from the gas storage unit. In this way, the cylindrical container functions as a heat exchanger and the gas storage unit eliminates the need for a separate heat exchanger and/or a separate coolant system. The structure and composition of the gas storage unit advantageously promotes energy efficiency, case-of-use, case-of-production, and reduction in weight.
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An additional advantage of extending the fluting along the entire length of the inner surface is that it provides flexibility in that the cylindrical container can be partitioned into a varying number of chambers as needed for a particular application. For instance, while the example gas storage unit 100 of
Yet another advantage of the fluting along the inner surface 131 of the cylindrical container 101 is that it forms a semicylindrical shape in the outer surface of the metal alloy where the metal alloy contacts the inner surface 131. The semi-cylindrical shape of the outer surface of the metal alloy fosters a helical flow path for the hydrogen as it moves through the metal alloy in a direction parallel to the longitudinal axis 107. A helical flow path can be beneficial because it can encourage more absorption of the hydrogen as it spends more time circulating through the metal alloy.
Lastly, yet another advantage of the fluting extending along the length of the inner surface is that it maintains symmetry about the central longitudinal axis 107. Maintaining a symmetrical interior volume of the gas storage unit can enhance the hydrogen storage capacity of the unit when a reciprocating element operating at a resonant frequency is used to pump hydrogen into the gas storage unit 100. The reciprocating element can be a solenoid, a vibration motor, a linear actuator, a piezoelectric drive, or a similar component. The reciprocating element can be located within the gas storage unit 100, for example as a component of an end anvil, or can be located external to the gas storage unit 100 and coupled to the coupler 105 or 108. An optional external reciprocating element 138 is illustrated as an example in
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The spacer disks provide other benefits as well. The spacer disks retain each of the intermediate anvils in the appropriate position and facilitate assembly of the gas storage unit. The spacer disks can be placed at various positions along the length of the gas storage unit to determine the length and the number of chambers within the gas storage unit.
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The fluted shape of the diaphragm 120 is received in the end anvil recesses 154 and the intermediate anvil recesses 147. While the diaphragm's fluted shape is received in the recesses of each anvil, the diaphragm flange 135 is held between the end anvil 102 and the first spacer flange 140 and, at the opposite end of the chamber, the diaphragm flange 136 is held between the first intermediate anvil 128 and the spacer flange of the second spacer disk 125. Accordingly, the arrangement of the anvil recesses and the spacer disks holds the diaphragm in place and the diaphragm, in turn, holds the metal alloy in place in the metal alloy chamber of the gas storage chamber.
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The example gas storage assemblies illustrated in
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For any apparatus shown and described herein, one or more of the components may be omitted, added, repeated, and/or substituted. Accordingly, embodiments shown in a particular figure should not be considered limited to the specific arrangements of components shown in such figure. Further, if a component of a figure is described but not expressly shown or labeled in that figure, the label used for a corresponding component in another figure can be inferred to that component. Conversely, if a component in a figure is labeled but not described, the description for such component can be substantially the same as the description for the corresponding component in another figure.
Referring generally to the examples herein, any components of the apparatus (e.g., the container, the anvils, the spacer disks), described herein can be made from a single piece (e.g., as from a mold, injection mold, die cast, 3-D printing process, extrusion process, stamping process, or other prototype methods). In addition, or in the alternative, a component of the apparatus can be made from multiple pieces that are mechanically coupled to each other. In such a case, the multiple pieces can be mechanically coupled to each other using one or more of a number of coupling methods, including but not limited to epoxy, welding, fastening devices, compression fittings, mating threads, and slotted fittings. One or more pieces that are mechanically coupled to each other can be coupled to each other in one or more of a number of ways, including but not limited to couplings that are fixed, hinged, removeable, slidable, and threaded.
Terms such as “first”, “second”, “top”, “bottom”, “side”, “distal”, “proximal”, and “within” are used merely to distinguish one component (or part of a component or state of a component) from another. Such terms are not meant to denote a preference or a particular orientation, and are not meant to limit the embodiments described herein. In the example embodiments described herein, numerous specific details are set forth in order to provide a more thorough understanding of the invention. However, it will be apparent to one of ordinary skill in the art that the invention may be practiced without these specific details. In other instances, well-known features have not been described in detail to avoid unnecessarily complicating the description.
Although example embodiments are described herein, it should be appreciated by those skilled in the art that various modifications are well within the scope of this disclosure. Those skilled in the art will appreciate that the example embodiments described herein are not limited to any specifically discussed application and that the embodiments described herein are illustrative and not restrictive. From the description of the example embodiments, equivalents of the elements shown therein will suggest themselves to those skilled in the art, and ways of constructing other embodiments using the present disclosure will suggest themselves to practitioners of the art. Therefore, the scope of the example embodiments is not limited herein.
The present application is a continuation application of and claims priority to PCT Patent Application No. PCT/US2023/063859 filed Mar. 7, 2023, which claims the benefit of U.S. Provisional Patent Application No. 63/317,413 filed Mar. 7, 2022. The entire content of the foregoing applications is incorporated herein by reference.
Number | Date | Country | |
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63317413 | Mar 2022 | US |
Number | Date | Country | |
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Parent | PCT/US2023/063859 | Mar 2023 | WO |
Child | 18817020 | US |