WO2005117559A2

WO2005117559A2 - Containers for hydrogen storage materials

Info

Publication number: WO2005117559A2
Application number: PCT/US2005/019504
Authority: WO
Inventors: Ken Stoorza
Original assignee: Fuelsell Technologies, Inc.
Priority date: 2004-06-02
Filing date: 2005-06-02
Publication date: 2005-12-15
Also published as: WO2005117559A3

Abstract

Disclosed herein are new and useful apparatus for containing hydrogen storage materials, and methods of making and using the apparatus. In one aspect, an apparatus may include a housing (100), an integral heat transfer structure (104) of the housing, a partitioned chamber (108) defined by the housing and partitioned by the heat transfer structure into a plurality of chamber portions, a hydrogen storage material contained in the partitioned chamber, the hydrogen storage material thermally coupled with the heat transfer structure to receive heat from the structure, and a port defined by the housing to allow hydrogen to be introduced into and removed from the apparatus.

Description

Containers for Hydrogen Storage Materials

BACKGROUND

Field

[0001] An embodiment of the invention relates to an apparatus to contain a hydrogen storage material.

Background Information

[0002] The widespread use of fossil fuels for energy and for powering internal combustion engine vehicles has created significant pollution problems in much of the industrialized world. Hydrogen provides a promising fossil fuel alternative. Hydrogen can be combined with oxygen via combustion, or through fuel cell mediated oxidation/reduction reactions, to produce heat, or electrical power. As a fuel, hydrogen offers a number of potential advantages including being abundant, affordable, clean, renewable, and having favorable energy density. The primary product of this reaction - water - is non-polluting and can be recycled to regenerate hydrogen and oxygen.

[0003] Unfortunately, existing approaches of storing, distributing, and recovering hydrogen are extremely limiting, and are a significant impediment to the widespread utilization of hydrogen as fuel, and the realization of the associated advantages. Consider for a moment one of the prevalent approaches, which involves using pressurized tanks or cylinders to store gaseous or liquefied hydrogen. This approach generally involves producing hydrogen gas, liquefying or pressurizing the hydrogen into a pressurized cylinder, shipping the cylinders to a point of use, and releasing the hydrogen from the cylinders. Now, mixtures of hydrogen and air may be flammable, and may have relatively low spark temperatures. As such, the storage, distribution, and use of hydrogen in such tanks is highly regulated and controlled. In order to provide improved safety, and due to the high pressures involved, the tanks are often heavy, and contain specialized explosion-proof components. As a result, the tanks are often expensive. Nevertheless, even with these precautions, there may still be a significant risk that hydrogen may be released, and explode, during loading, unloading, or distribution. Such risks may render the tanks or cylinders unfavorable for powering vehicles. Accordingly, the costs and dangers associated with prior art techniques for storing and distributing hydrogen may be prohibitive, and may limit the utilization of hydrogen as fuel.

[0004] Thus, the potential for using hydrogen as a fuel is great, but there are significant and limiting problems with conventional approaches for storing, distributing, and recovering hydrogen.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

[0005] The invention may best be understood by referring to the following description and accompanying drawings that are used to illustrate embodiments of the invention. In the drawings:

[0006] Figure 1 shows an exploded perspective view of a hydrogen storage container 100, according to one embodiment of the invention. [0007] Figure 2 shows a transverse cross sectional view of a heat transfer structure including a corrugated top, and a non-corrugated bottom, according to one embodiment of the invention.

[0008] Figure 3 shows a transverse cross sectional view of a heat transfer structure including thermally conductive partitions disposed within hydrogen storage material, according to one embodiment of the invention.

[0009] Figure 4 shows a transverse cross sectional view of a heat transfer structure including thermally conductive horizontal partitions, according to one embodiment of the invention.

[0010] Figure 5 shows a transverse cross sectional view of a heat transfer structure including intersecting vertical and horizontal partitions, according to one embodiment of the invention.

[0011] Figure 6 shows a transverse cross sectional view of a heat transfer structure including protrusions or fins that span a portion of a transverse cross- sectional distance of the container, according to one embodiment of the invention.

[0012] Figure 7 shows a transverse cross sectional view of a heat transfer structure including branched partitions or fins, according to one embodiment of the invention.

[0013] Figure 8 shows a transverse cross sectional view of a heat transfer structure including a partitioned chamber that includes a plurality of separate chambers arranged in a reticulated or grid-like arrangement, according to one embodiment of the invention. [0014] Figure 9 shows a transverse cross sectional view of a heat transfer structure including a partitioned chamber that has a seφentine cross section, according to one embodiment of the invention.

[0015] Figure 10 shows an exploded perspective view of a hydrogen storage container, according to another embodiment of the invention.

[0016] Figure 11 shows a top view of a heat transfer structure including a seφentine chamber, fastener holes, hydrogen collection reservoirs, and hydrogen collectors in the reservoirs, according to one embodiment of the invention.

[0017] Figure 12 shows a hydrogen storage container including a hydrogen storage material, and a hydrogen recovery system to recover hydrogen from the container, according to one embodiment of the invention.

DETAILED DESCRIPTION

[0018] Disclosed herein are new and useful apparatus for containing hydrogen storage materials, and methods of making and using the apparatus. In the following description, numerous specific details are set forth. However, it is understood that embodiments of the invention may be practiced without these specific details. In other instances, well-known structures and techniques have not been shown in detail in order not to obscure the understanding of this description. I. Introduction

[0019] Solid-state hydrogen storage materials may offer a promising alternative to storing hydrogen as a compressed gas or liquid. Exemplary solid- state hydrogen storage materials include, but are not limited to, metal hydrides, carbon nanotubes, and glass microspheres. The solid-state hydrogen storage materials generally have a hydrogen-charged state, where they may be referred to as hydrogen storing materials, and an uncharged state. As used herein, the term hydrogen storage material may refer to the material in either the charged or uncharged states.

[0020] These materials may provide a significantly safer way to store the hydrogen compared to compressed or liquefied hydrogen. For one thing, the risks of unintended release of the hydrogen (e.g., in the event of a rupture or damage of the tanks or cylinders), and the corresponding risks of flammability and explosion, may be significantly reduced. This may be advantageous for onboard storage of hydrogen for hydrogen-powered vehicles.

[0021] The solid-state hydrogen storage materials may be heated in order to increase their temperature and allow recovery of hydrogen. The increased temperature may help to free the hydrogen from the materials. In the case of metal hydrides, the increased temperature may break chemical bonds between the hydrogen and the metal. In the case of nanotubes, the increased temperature may allow the hydrogen to desorb from the surfaces of the nanotubes. Finally, in the case of glass microspheres, the increased temperature may allow the hydrogen to permeate the walls of the microspheres. [0022] The rate and extent of hydrogen recovery from these and other solid-state hydrogen storage materials may depend directly on the ability to effectively heat the materials and increase their temperature. The inventor has recognized that the materials often have relatively poor heat transfer characteristics. The materials may have low thermal conductivities and conduct heat slowly. As a result, substantial temperature gradients or non-uniform temperature profiles may occur across a thickness of metal hydride during heating. Portions of metal hydride immediately adjacent to a heated surface may have a temperature that is about equal to that of the surface, while other portions of the metal hydride a significant distance away from the heated surface may have a substantially lower temperature. Also, a significant time lag may be expected in order to heat all of the material to a temperature that allows efficient hydrogen recovery. A potential drawback is that excessive amounts of material may be needed to satisfy an instantaneous demand for hydrogen. Additionally, the poor heat transfer characteristics may make it impractical to recover all of the hydrogen. This lack of full hydrogen recovery may also increase the amount of hydrogen storage material that is employed. This may increase the cost and volume of material needed to supply a given hydrogen demand. Accordingly, the relatively poor heat transfer characteristics of these hydrogen storage materials may cause slower and incomplete hydrogen recovery, and may increase the amount of material needed to supply the requisite hydrogen.

[0023] The inventor has developed novel apparatus for containing solid- state hydrogen storage materials that allow more effective heating of the hydrogen storage material. It is hoped that the apparatus may significantly advance the art of storing and recovering hydrogen from solid-state hydrogen storage materials.

TI. Exemplary Container

[0024] Figure 1 shows an exploded perspective view of a hydrogen storage container 100, according to one embodiment of the invention. The container includes a housing 102, 104, 106. The housing includes opposed, parallel, transverse front and rear ends 102 and 106, respectively, and an integral, elongated, heat transfer structure 104 that provides longitudinal sides for the housing. The transverse front end, and the rear end of the container, may seat against the respective ends of the heat transfer structure, as shown by the dashed lines. The front and rear ends may include thermally conductive materials, such as metals, or non-thermally conductive materials, such as plastics. The front and rear ends may be attached to the heat transfer structure by molding, welding, with an adhesive, such as glue, or with various other fasteners known in the arts, such as screws, bolts, rivots, joints, or clamps. If desired, gaskets may be employed to improve the seal. The housing defines an interior chamber 108 that may be used to contain a metal hydride or other hydrogen storage material.

[0025] The heat transfer structure may exchange heat with the hydrogen storage material. The heat transfer structure may be shaped to intimately contact the material and may include a thermally conductive material to conduct heat into the material (in the case of heating), or out of the material (in the case of cooling).

Suitable thermally conductive materials include, but are not limited to, metals, such as aluminum, brass, copper, steel, stainless steel, titanium, other metals known in the arts, and combinations of such metals. As used herein, the term metal includes alloys, laminates, blends, and other mixtures. Thermally conductive ceramics, thermally conductive plastics, and other thermally conductive non-metals may also optionally be employed.

[0026] The chamber 108 is partitioned by the heat transfer structure 104.

In the illustrated embodiment, the heat transfer structure includes corrugated longitudinal sides, including alternating longitudinal ridges and grooves. In particular, the illustrated top longitudinal surface includes three grooves, and the bottom longitudinal surface includes two grooves. In other embodiments of the invention more or fewer ridges and grooves may be employed. The alternating ridges and grooves of the corrugated sides partition the chamber into a plurality of chamber portions, or windings. The chamber portions, or windings, may contain hydrogen storage material. The corrugated longitudinal sides may offer an increased heat transfer surface thermally coupled with, not necessarily in direct contact with, the hydrogen storage material. As is known, the rate of heat transfer typically increases with increasing heat transfer area.

[0027] In the illustrated embodiment, the alternating ridges and grooves of the top longitudinal side are interdigitated with the alternating ridges and grooves of the bottom opposing longitudinal side. With such interdigitation, the top and the bottom surfaces may substantially parallel one another. The distance between the top and the bottom surfaces may be about uniform across the transverse cross section. The domain of the hydrogen storage material may be limited or restricted to the thin space or gap between the interdigitated ridges and grooves. The hydrogen storage material may be within close proximity to the heat transfer surface of the corrugated longitudinal sides. Accordingly, heat may not need to be conducted through great distances within the hydrogen storage material. Instead, the heat may be conducted along relatively short thermal paths from the corrugated surface to all portions of the hydrogen storage material. This may make the heating of the material more uniform and may help to reduce the magnitude or severity of thermal gradients across the hydrogen storage material. This may help to promote faster and more complete hydrogen recovery. It may also help to reduce the thermal time constant or lag time associated with changing the rate of hydrogen recovery.

[0028] It is difficult to place a precise circumference on the appropriate dimensions of the gap, since this may depend upon the heat transfer characteristics of the hydrogen storage material, and otherwise depend upon the particular implementation. However, in various embodiments, a gap distance that is sufficient to limit the thermal gradient to less than about 5°C or 10°C during hydrogen recovery may be appropriate. In another aspect, the gap may be in the range between about 0.5 cm to 5 cm, or in the range between about 0.5 cm and 2 cm.

[0029] Now, let's consider exemplary methods of making the container.

In one embodiment of the invention, a method of making a hydrogen storage apparatus or container, such as the container 200, may include extruding a metal to form a structure, such as the heat transfer structure 204, having an internal chamber that is partitioned into a plurality of chamber portions. The method may then include attaching a first housing portion, such as the front end 202, to the structure at a first end of the chamber. Next, a hydrogen storage material, such as a metal hydride, may be introduced into the chamber. The hydrogen storage material may be introduced into the container in a charged or uncharged state. In the case of an uncharged material, the uncharged material may subsequently be charged with hydrogen after assembly of the housing. Then, a second housing portion, such as a rear end 206, may be attached to the structure at a second end of the chamber to close the hydrogen storage material in the chamber.

[0030] In extruding the metal, the metal may be shaped by forcing the metal through a die. A variety of metals may be extruded. Examples include, but are not limited to aluminum, copper, brass, and steel. Aluminum is often favored due to its unique properties, low cost, and relatively high thermal conductivity. In one aspect, a result or product of the extrusion may include an extruded structure that has features similar to the heat transfer structure 204. In other aspects, the result or product may have features similar to the other heat transfer structures disclosed herein. In a manufacturing environment, it may be appropriate to extrude a running length of metal, and then cut or otherwise divide the length into sections of extruded metal having predetermined lengths, although this is not required.

[0031] The use of extrusion may offer a number of potential advantages.

For one thing, extrusion is a well-known and well-tested manufacturing technique that has been practiced for numerous years. For another thing, extrusion generally lends itself to low-cost and mass production. Still further, the equipment needed for extrusion is generally widely available and relatively inexpensive. The inventor has recognized that extrusion may be well suited for forming the heat transfer structures disclosed herein. However, extrusion is not required. Other approaches, such as cutting, drilling, molding, and like approaches known in the arts of manufacturing shaped structures may also optionally be employed.

[0032] In attaching the housing portions, such as the front end 202 and the rear end 206, the portions may be attached to the structure by molding, welding, with an adhesive, such as glue, or with various other fasteners known in the arts, such as screws, bolts, rivots, joints, or clamps. If desired, gaskets may be employed to improve the seal. The housing portions may include thermally conductive materials, such as metals (e.g., aluminum), or non-thermally conductive materials, such as plastics.

[0033] Now, a potential problem with hydrogen, and certain hydrogen storage materials, is that they may corrode or otherwise react with certain materials or metals that may be employed in the heat transfer structure. In one embodiment of the invention, an optional protective material or optional coating (not shown) may be used to separate or protect a material of the structure from directly contacting the hydrogen or hydrogen storage material. This may help to reduce the amount of corrosion or reaction.

[0034] The inventor has discovered a novel method of forming a protective coating of a molding material, and concurrently and integrally attaching a molded end of the housing, such as the front end 202, using a molding operation. An exemplary method may include, after forming the extruded structure, and prior to attaching the first housing portion, placing the extruded structure in a molding tool. The molding tool may be similar to those conventionally used in double-shot molding. Then, a mold core or mandrel similar to the type conventionally used in double shot molding may be introduced into a partitioned chamber of the structure. The mold core may have substantially the same shape as the partitioned chamber or void of the structure and may have a size configured to leave a thin void or gap between a surface of the partitioned chamber and a surface of the mold core. The gap may correspond to the desired thickness of the protective coating.

[0035] Next, a molding material, such as a plastic material, may be introduced into the molding tool, and into the gap. In one aspect, the molding material may also be introduced into a portion of the molding chamber corresponding to the end, such as the front end, or other portion of the container. The molding material may then be solidified in the gap, and in the portion corresponding to the end, to form a coating attached to the surface of the partitioned structure, and an integral molded portion of the housing, such as a molded front end 202. The coating may be attached to the heat transfer structure on the inner surface of the corrugated chamber. Forming the coating integral with the end by such a molding operation may help to provide strength and integrity to the apparatus, and may help to seal the container.

[0036] It is difficult to place a precise circumference on the appropriate thickness of the coating inasmuch as this may depend on the appropriate level of protection and the heat transfer characteristics of the coating. For many plastic materials, which often have relatively low thermal conductivity, thin coatings of not more than several millimeters may be appropriate in order to avoid unduly limiting heat transfer.

[0037] It is worth noting that the coating is optional and not required.

Further, even if the coating is desired, it is not required to form the coating by such a molding operation. In various embodiments of the invention, the material or coating may be formed on the inner surface of the chamber by spraying, coating, painting, plating, depositing, reacting, laminating, and by other approaches known in the arts. The material or coating need not include a molding material, but may include a plastic, metal, inorganic, glass, enamel, or other material. As one example, a halogenated or fluorinated polymer, such as polytetrafluoroethylene, may be formed on the inner surface. As another example, a metal that is more compatible than a metal of the heat transfer structure may be electroplated, sputtered, or deposited on the surface. As yet another example, enamel, glass, or another inorganic may be formed on the surface. It may be appropriate for the chosen material or coating to have similar coefficient of thermal expansion with the structure to prevent cracking, separation, or other defects during routine temperature excursions.

[0038] Referring again to the method of manufacturing the container, after attaching the first end, the rear end of the housing may be attached. The ends may also be attached in the reverse order. As shown in Figure 12, the apparatus will often be used in conjunction with a receiving system, such as a hydrogen charging or recovery system. The rear end of the illustrated container includes several features that may interact with features of the receiving system. In particular, the rear end includes a plurality of heat exchange member insertion openings 112 to allow insertion of heat exchange members of the system, and a hydrogen port 110 to couple with the system to introduce or remove hydrogen. The plurality of insertion openings will be discussed first, and then the hydrogen port will be discussed. [0039] The illustrated rear end of the container includes five heat exchange member insertion openings 112. The openings include rectangular cutouts that are similar in size, shape, and position to the rectangular transverse cross sections of the grooves of the longitudinal sides. The openings may allow insertion or introduction of five heat exchange members of a hydrogen recovery system into the grooves. The heat exchange members may include thermal heating or cooling tubes, panels, vanes, rods, prongs, or other members. The heat exchange members may exchange heat with the heat transfer structure, for example provide heat to the heat transfer structure. The heat exchange may be by conduction, convection, radiation, or some combination. Now, the particular illustrated openings, number of openings, and other features of the illustrated embodiment are not required. In other embodiments of the invention, the container may include one or more openings, of any appropriate size, shape, and position, to allow introduction of one or more heat exchange members into one or more open structures of the container.

[0040] Further, the opemngs in the rear end are not required. As another option, rather than introducing the heat exchange members through openings in the rear end, the openings in the rear end may be omitted, and retractable heat exchange members may be introduced into the grooves or other open structures of the container in a generally vertical direction (as shown). For example, the heat exchange members may be introduced from the top, bottom, or both the top and the bottom, after the container has been coupled with the port of the hydrogen recovery system. [0041] Still further, as yet another option, the openings and the heat exchange members may each be omitted, and heat may be exchanged with the heat transfer structure by other approaches. For example, convection or radiant heat transfer may be used to provide heat to the corrugated surface.

[0042] Now, let's discuss the hydrogen port 110 located lat or near the rear end of the container. The port may allow hydrogen to be removed from, and in certain cases introduced into, the container. The illustrated hydrogen port includes two generally spaced apart openings that may each be equipped with a valve or other hydrogen flow regulator. The two openings are not required, and fewer or more openings may also optionally be employed. Also, the use of valves or other regulators are not required, although their use will often be appropriate to regulate the flow of hydrogen into or out of the container. The valves may also help to restrict the introduction of air, water, and other foreign substances into the container.

[0043] In certain cases, it may be appropriate to prescribe an orientation for coupling the container with a receiving system. For example, this may be appropriate when a powder or other material capable of settling within the container is employed. Referring again to Figure 1, the illustrated apparatus includes an optional keying system 114 defined by the housing. The keying system may provide an orientation for coupling the apparatus with another system, such as a hydrogen recovery system, hydrogen charging system, or another receiving system. The keying system may include a shaped portion of the housing of the container. The illustrated keying system includes a groove defined by the longitudinal sides and a corresponding rectangular cutout in the rear end. The keying system may be aligned with a direction that the container is to be inserted into or otherwise coupled with the receiving system. This may provide a coupling orientation, such as right-side up instead of upside down. Alternatively, instead of using the optional keying system, in another embodiment of the invention, a label e.g., "top" or other indication of orientation may be affixed to the container to allow an orientation to be determined.

[0044] When appropriate, heat may be provided to the container, and the heat may be transferred through the heat transfer structure, and into the hydrogen storage material. The heating may allow recovery of hydrogen that may be provided from the hydrogen port to a hydrogen recovery system. During heating, the integral heat transfer structure, and the partitioned chamber, may allow improved heat exchange with the hydrogen storage material in the container. The heat transfer structure includes the corrugated sides to intimately contact the hydrogen storage material with a relatively large mutual heat transfer surface. Additionally, the corrugations partition the material and restrict and make umform the shortest thermal path distance from the heat transfer structure to the hydrogen storage material. The inventor hopes and believes that these and other features of the container may help to reduce thermal gradients, help to increase the rate and extent of hydrogen recovery, and generally help to advance the art of hydrogen storage and distribution.

III. Other Exemplary Heat Transfer Structures

[0045] The particular heat transfer structure shown in Figure 1 is exemplary and is not required. Numerous other heat transfer structures may also optionally be employed. Figures 2 to 9 show transverse cross sectional views of different heat transfer structures and partitioned chambers, according to various embodiments of the invention. Many other embodiments are also contemplated, and will be apparent to those skilled in the art and having the benefit of the present disclosure. Each of the heat transfer structures may be formed by extrusion, if desired.

[0046] Both the top and the bottom of the heat transfer structure need not be corrugated, and the interdigitation of ridges and grooves is not required. As shown in Figure 2, a heat transfer structure 200 may include a corrugated top 210 and a non-corrugated bottom 220. Further, the use of corrugated surfaces is not required.

[0047] As shown in Figure 3, a heat transfer structure 300 may include one or more thermally conductive vertical partitions 310 disposed within the hydrogen storage material in order to partition the chamber into separate chambers or compartments. The partitions may include metal heat transfer fins running from the bottom to top of the container, and extending in the longitudinal direction substantially from the front to the rear. Also, as shown in Figure 4, a heat transfer structure 400 may include horizontal thermally conductive partitions 410 instead of vertical partitions. As yet another option, as shown in Figure 5, a heat transfer structure 500 may include intersecting vertical 510 and horizontal thermally conductive partitions 520 forming a reticulated or grid-like structure of separate chamber portions or compartments. The separate chamber portions or compartments between the partitions may be used to contain hydrogen storage material. The partitions of the heat transfer structure may intimately contact the hydrogen storage material with a large heat transfer surface, and restrict and make more uniform the thermal path distance to the material.

[0048] There is no requirement that the partitions or fins span the entire transverse cross-sectional distance of the container. As shown in Figure 6, a heat transfer structure 600 may include thermally conductive protrusions such as partial partitions or fins 610 that span only a portion, for example about half, of the distance from one side to another. In such case, the partial partitions or fins may be interdigitated and substantially equally spaced. In another embodiment, partial partitions or fins may be on only one side of the container, such as the bottom. As shown in Figure 7, a heat transfer structure 700 may include branched partitions 710 that include branches 720. This may help to increase the heat transfer area in contact with the hydrogen storage material and increase the rate of heat transfer. The branches may also optionally be used on full partitions, corrugated surfaces, and the like.

[0049] In one aspect, the heat sink fin may include a temperature measurement device, such as a thermocouple. If desired, the temperature measurement device may be coupled with a temperature control system, which may control a temperature sufficient to accommodate a relevant hydrogen demand.

[0050] The use of vertical or horizontal surfaces is not required and curved or angled surfaces may also optionally be employed. As shown in Figure

8, a heat transfer structure 800 may include a partitioned chamber that includes a plurality of separate circular-cross sectioned chambers 810 arranged in a reticulated or grid-like arrangement. Triangular, square, rectangular, polygonal, oval, and other cross sections may also optionally be employed. Further, the use of regular, same-sized shapes, and the reticulated or grid-like arrangement, are not required, but may help to maintain a relatively uniform distance between the heat transfer structure and the hydrogen storage material in the partitioned chamber.

[0051] As shown in Figure 9, a heat transfer structure 900 may include a partitioned chamber 910 that has a seφentine cross section. The seφentine cross section may include chamber portions that wind back and forth relative to one another.

[0052] Accordingly, the heat transfer structure may partition the chamber into narrow regions, such as winding seφentine chambers, or into individual smaller chambers, partitions, compartments, cubbyholes, other small places, in intimate contact with the thermally conductive portions of the heat transfer structure, which may be used to store a hydrogen storage material.

IV. Another Exemplary Container

[0053] The particular shape, orientation, and configuration of the container of Figure 1 are not required. In that container, the heat transfer structure was elongated in the longitudinal direction from the front end to the rear end. This may coincide with the extrusion direction. However, in another embodiment of the invention, a relatively shorter section of an extrusion running length may be cut, the heat exchange structure may be flipped so that the chamber runs vertically instead of longitudinally, and the front and the rear ends may be replaced by top and bottom. Further, as elsewhere herein, it should be noted that terms such as "top", "bottom", "front", "rear", "longitudinal", "transverse", and the like, are used herein only to facilitate the description of the containers as illustrated. It will be evident that the containers may be used in a variety of orientations.

[0054] Figure 10 shows an exploded perspective view of a solid-state hydrogen storage material container 1000, according to another embodiment of the invention. The container includes a housing 1002, 1004, 1006. The housing includes opposed, parallel, longitudinal top 1002 and bottom 1006, and an integral, elongated, heat transfer structure 1004 that provides longitudinal right and left sides, and front and rear ends, for the housing. The top and the bottom of the container may seat against the upper and lower planar surfaces of the heat transfer structure, as shown by the dashed lines. The housing defines an interior chamber 1008, which is partitioned by the heat transfer structure, and which may be used to contain a metal hydride or other hydrogen storage material.

[0055] Now, the container 1000 of Figure 10 may have features similar to those of the container 100 of Figure 1. For example, the heat transfer structure may include a section of extruded metal, the container may include an optional protective material or coating, the coating may be formed using a molding operation, if desired a molded top may be formed integrally with the molded coating during the molding operation, an optional keying system may be employed (e.g., a groove in a longitudinal right or left side of the heat transfer structure), etc. Generally the discussion below will focus primarily on the different and/or additional features in connection with the container illustrated in Figure 10, in order to avoid obscuring the description. [0056] As discussed, the heat transfer structure may include a thinner section of an extruded metal. The section is flipped or re-orientated such that the chamber runs from top to bottom, rather than front to rear. The illustrated heat transfer structure includes three interdigitated partitions. The interdigitated partitions partition the chamber into chamber portions or seφentine windings (e.g., the chamber has a seφentine cross section). The seφentine windings may include chamber portions that wind back and forth relative to one another. Another suitable partitioned chamber including seφentine windings is shown in Figure 11, which will be discussed further below. Still further, the use of seφentine windings is not required, and many alternate designs, including but not limited to those shown in Figures 2-9, may also optionally be employed.

[0057] The illustrated container includes a hydrogen port 1010 at or near the bottom of the container, although this location is not required. The port may also optionally be located at the top, or at another location. In the illustrated aspect, the bottom may seat against or mate with a corresponding surface of a reception system, such as a hydrogen charging system, or a hydrogen recovery system. In this aspect, the bottom may include a thermally conductive material, such as a metal plate. The thermally conductive material may help to provide additional conductive surface area to exchange heat between the container and the reception system. However, this is not required, and heat may also be transferred through the longitudinal, front, and rear sides of the heat transfer structure.

[0058] Now, let's discuss an alternate heat transfer structure and partitioned chamber that may also optionally be employed. Figure 11 shows a top view of a heat transfer structure 1100, according to another embodiment of the invention. The heat transfer structure includes a partitioned seφentine chamber 1110 including seφentine windings, fastener holes 1120, and hydrogen collection reservoirs 1130.

[0059] The fastener holes may include cylindrical holes or openings all the way through the structure. The holes may be formed by extrusion or drilling, for example. In one aspect, a top and a bottom may be bolted to the structure by introducing bolts, screws, dowels, or other fasteners through the holes.

[0060] The illustrated heat transfer structure also includes the two hydrogen collection reservoirs to help to collect hydrogen from the material. The reservoirs may represent wide spots or enlarged portions of the partitioned chamber. The reservoirs may be fluidically coupled with the seφentine windings of the chamber to provide a hydrogen flow path from the seφentine windings or chamber portions to the reservoirs.

[0061] In one aspect, as in the illustrated structure, the reservoirs 1130 may be sized and configured to accommodate hydrogen collectors 1140. In the illustration, two hydrogen collectors are inserted into the reservoirs in order to illustrate partitioning. The hydrogen collectors may include a hydrogen permeable media, such as a porous or packed material. Exemplary hydrogen collectors may include a wire mesh, a porous ceramic plug, a hollow filter, a packed bed, and the like. The collectors may include a void volume to collect hydrogen from the seφentine chambers and may help to keep the hydrogen storage material from leaving the port. The collectors may be fluidically coupled with the hydrogen port, such as a valved opening, to provide the collected hydrogen to the port. Also, while two collectors are shown, fewer or more collectors, and reservoirs, may also optionally be employed.

V. Exemplary Container And Hydrogen Recovery System

[0062] Figure 12 shows a hydrogen storage container 1210 including a hydrogen storage material 1215, and a hydrogen recovery system 1230 to recover hydrogen from the container, according to one embodiment of the invention. The container and the material may be similar to those disclosed elsewhere herein, and will not be discussed in further detail in order to avoid unnecessarily obscuring the description.

[0063] The hydrogen recovery system generally represents a system that may recover hydrogen from the container. In various aspects, the hydrogen recovery system may include a dedicated stand-alone hydrogen recovery system, a dedicated hydrogen storage system aboard a vehicle or other apparatus, or an integrated hydrogen storage system within a hydrogen-powered vehicle or other hydrogen utilization system.

[0064] When appropriate, such as when it is needed to power a fuel cell or hydrogen powered vehicle, hydrogen may be recovered from the container. Initially, the container may be physically and thermally coupled with the hydrogen recovery system. The hydrogen recovery system includes a port 1235 that may be coupled with the container. Different physical and thermal couplings of the container and the recovery system are suitable. In one aspect, the container and the recovery system may be physically coupled in order to complete a hydrogen flow path from the interior of the container to pipes, tubes, valves, chambers, or other hydrogen containment components of the hydrogen recovery system. In one example, a rear end of the container having a valve may be positioned relative to the port of the hydrogen recovery system such that the valve of the container may be coupled with a valve coupling of the hydrogen recovery system to allow hydrogen to be recovered from the cassette and provided via a controlled hydrogen flow path from the container to the hydrogen recovery system. Other conventional physical coupling components may also optionally be employed. Also, it is not required that the hydrogen recovery system include valves, chambers, and other components. In one aspect, the hydrogen recovery system may simply include a pipe or other relatively simple flow path to directly couple the port of the container with a hydrogen utilization system.

[0065] The container and the hydrogen recovery system may also be thermally coupled. In one aspect, the thermal coupling may include inserting or introducing the container into a heat exchange chamber of the hydrogen recovery system. Then, heat may be exchanged between the chamber and the container. The container may be heated by convection similarly to the way items may be heated in a conventional convection oven. A heating lamp may also optionally be employed in the chamber. In another aspect, the thermal coupling may include coupling a heat exchange member of the hydrogen recovery system with the container. For example, a prong, vane, or other member of the recovery system may be coupled with the container. The member may be inserted into opening in the housing of the container, for example. Other approaches for coupling the container and the hydrogen recovery system will be apparent to those skilled in the art and having the benefit of the present disclosure. [0066] Now, the container may be either at least partially inserted into the port of the recovery system, or not, depending upon the particular implementation. As one example, the container may have a cassette form factor and may be essentially completely inserted into the port in like way that a cassette tape may be inserted into a video cassette recorder. If desired, the recovery system and the container may each include a keying system to provide an orientation to couple or insert the container into the recovery system. Alternatively, as another example, the container may have any appropriate form factor, and may be brought into contact with, or at least into close proximity to, a surface of the hydrogen recovery system. As the container is brought into close proximity to the hydrogen recovery system, the port of the container may be physically coupled with the port of the recovery system to complete a physical coupling and hydrogen flow path, and a thermal coupling between the container and the recovery system may also be completed. In one aspect, a heat exchange member of the recovery system may be introduced into an opening of the container. Alternatively, in another aspect, thermal coupling or contact may be made between heat exchange surface (e.g., a thermally conductive rear end) of the container and an adjacent heat exchange surface of the recovery system.

[0067] When appropriate, the hydrogen recovery system may provide heat to the container in order to allow recovery of hydrogen. The invention is not limited to any known source of the heat. In one aspect, the hydrogen recovery system may generate the heat. For example, the hydrogen recovery system may include electrical resistance heaters or elements. Alternatively, in another aspect, the hydrogen recovery system may channel or direct heat from a heat source, such as an engine of a vehicle, to the container. [0068] The container may receive the heat and transport the heat into the hydrogen storage material within the container. As previously discussed, the containers may include novel heat transfer structures to provide more rapid and umform heating of the hydrogen storage material. This may allow faster and more complete hydrogen recovery.

[0069] The hydrogen cargo recovered from the container may be provided along the hydrogen flow path to the hydrogen recovery system. In various embodiments of the invention, the hydrogen may be stored within the hydrogen recovery system, used within the hydrogen recovery system (e.g., within a fuel cell), or provided to a hydrogen utilization system. Suitable hydrogen utilization systems include, but are not limited to, hydrogen fuel cells, hydrogen-combustion engines, hydrogen-consuming chemical reactions, and other apparatus or processes that may utilize hydrogen. The fuel cells or engines may be incoφorated in myriad electrical devices and other apparatus known in the arts, such as vehicles, computer systems, cell phones, satellites, batteries, lawnmowers, and cooking grills.

VI. Other Matters

[0070] In the description above, for the puφoses of explanation, numerous specific details are set forth in order to provide a thorough understanding of the embodiments of the invention. It will be apparent, however, to one skilled in the art that another embodiment may be practiced without some of these specific details. In other instances, well-known circuits, structures, devices, and techniques have been shown in block diagram form or without detail in order not to obscure the understanding of this description. [0071] Many of the methods are described in their most basic form, but operations may be added to or deleted from any of the methods without departing from the basic scope of the present invention. It will be apparent to those skilled in the art that many further modifications and adaptations may be made. The particular embodiments are not provided to limit the invention but to illustrate it. The scope of the invention is not to be determined by the specific examples provided above but only by the claims below.

[0072] It should also be appreciated that reference throughout this specification to "one embodiment" or "an embodiment" indicates that a particular feature may be included in the practice of the invention. Similarly, it should be appreciated that in the foregoing description of exemplary embodiments of the invention, various features are sometimes grouped together in a single embodiment, Figure, or description thereof for the puφose of streamlining the disclosure and aiding in the understanding of one or more of the various inventive aspects. This method of disclosure, however, is not to be inteφreted as reflecting an intention that the claimed invention requires more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive aspects lie in less than all features of a single foregoing disclosed embodiment. Thus, the claims following the Detailed Description are hereby expressly incoφorated into this Detailed Description, with each claim standing on its own as a separate embodiment of this invention.

[0073] In the claims, any element that does not explicitly state "means for" performing a specified function, or "step for" performing a specified function, is not to be inteφreted as a "means" or "step" clause as specified in 35 U.S.C. Section 112, Paragraph 6. In particular, the use of "step of in the claims herein is not intended to invoke the provisions of 35 U.S.C. Section 112, Paragraph 6.

[0074] While the invention has been described in terms of several embodiments, those skilled in the art will recognize that the invention is not limited to the embodiments described, but may be practiced with modification and alteration within the spirit and scope of the appended claims. With respect to the above description then, it is to be realized that the dimensional relationships for the parts of the invention, to include variations in size, materials, shape, form, function and manner of operation, assembly and use, are deemed readily apparent to one of ordinary skill in the art, and all equivalent relationships to those illustrated in the drawings and described in the specification are intended to be encompassed by the present invention. The description is thus to be regarded as illustrative instead of limiting.

Claims

CLAIMS What is claimed is:

1. An apparatus comprising: a housing; an integral heat transfer structure of the housing; a partitioned chamber defined by the housing and partitioned by the heat transfer structure into a plurality of chamber portions; a hydrogen storage material in the partitioned chamber, the hydrogen storage material thermally coupled with the heat transfer structure to exchange heat with the structure; and a port defined by the housing to allow hydrogen to be removed from the apparatus.

2. The apparatus of claim 1, wherein the integral heat transfer structure comprises a section of extruded metal.

3. The apparatus of claim 2, wherein the section of extruded metal comprises aluminum.

4. The apparatus of claim 1 , wherein the heat transfer structure comprises corrugations including alternating ridges and grooves.

5. The apparatus of claim 4, wherein the corrugations comprise an alternating ridge and groove of a first side interdigitated with an alternating ridge and groove of an opposing second side.

6. The apparatus of claim 5, wherein the corrugations comprise shortest distances between an inner surface of the first side and an inner surface of the opposing second side that are equal.

7. The apparatus of claim 4, further comprising: a rear end; and an opening in the rear end corresponding in location to a groove of the corrugated shape to allow a heat exchange member to be introduced through the opening and into the groove.

8. The apparatus of claim 1, wherein the heat transfer structure comprises a plurality of thermally conductive partitions to partition the chamber.

9. The apparatus of claim 8, wherein the partitions comprise heat transfer fins.

10. The apparatus of claim 1, wherein the heat transfer structure comprises a plurality of separate compartments.

11. The apparatus of claim 10, wherein the separate compartments have substantially the same size, and shape, and are in a reticulated arrangement.

12. The apparatus of claim 1, wherein the heat transfer structure comprises a partitioned chamber including seφentine windings.

13. The apparatus of claim 1 , further comprising a protective coating attached to an inner surface of the partitioned chamber between a material of the heat transfer structure and the hydrogen storage material.

14. The apparatus of claim 13: wherein the protective coating comprises a molded material; and further comprising a molded portion of the housing molded integral with the protective coating.

15. The apparatus of claim 1 , further comprising a keying system defined by the housing to provide an orientation to couple the apparatus with a hydrogen recovery system.

16. The apparatus of claim 1, wherein the port comprises an opening and a flow regulator to regulate a flow through the opening.

17. An apparatus comprising: a housing; a transverse front end of the housing; a rear end of the housing; an integral heat transfer structure of the housing, the structure providing longitudinal sides of the housing, wherein the integral heat transfer structure comprises a section of extruded metal; a partitioned chamber defined by the housing and partitioned by the heat transfer structure into a plurality of chamber portions; a hydrogen storage material contained in the partitioned chamber, the hydrogen storage material thermally coupled with the heat transfer structure to exchange heat with the structure; and a port defined by the housing to allow hydrogen to be introduced into and removed from the apparatus, wherein the port includes an opening and a flow regulator to regulate flow through the opening.

18. The apparatus of claim 17 : wherein the front end comprises a molded material; and further comprising a protective coating attached to an inner surface of the partitioned chamber and molded integral with the molded material of the front end.

19. A method comprising: extruding a thermally conductive material to form a structure having an internal chamber that is partitioned into a plurality of chamber portions; attaching a first housing portion to the structure at a first end of the chamber; introducing a hydrogen storage material into the chamber; and attaching a second housing portion to the structure at a second end of the chamber to close the hydrogen storage material in the chamber.

20. The method of claim 19, further comprising, prior to said attaching the first housing portion, cutting a section of the extruded structure to a predetermined length.

21. The method of claim 19, further comprising, prior to said attaching the first housing portion: placing the extruded structure in a molding tool; introducing a mold core into the partitioned chamber to leave a gap between a surface of the partitioned chamber and a surface of the mold core; introducing a plastic material into the gap; and solidifying the plastic in the gap to form a plastic coating on the surface of the partitioned structure.

22. The method of claim 21 , wherein attaching the first housing portion comprises introducing plastic material into a portion of the molding tool near the first end of the chamber and solidifying the plastic material to form the first housing portion integrally with the plastic coating.