ES2733017T3 - Use of means to support a selective hydrogen membrane to prevent wrinkling of said membrane - Google Patents

Abstract

The use, to prevent the formation of wrinkles of at least one selective hydrogen membrane (46, 202) in a hydrogen purification device (10) comprising an enclosure (12) that defines an internal compartment (18) and contains a separation unit (20), which divides the internal compartment into a mixed gas region (30) and a permeate region (32), the hydrogen purification device that is adapted to receive a mixed gas stream (24) that it contains hydrogen gas (26) and other gases (28) and to produce a stream (34), which contains pure or at least substantially pure hydrogen gas, wherein the substantially pure hydrogen gas has a purity greater than 90%, and a current by-product (36), which contains at least a substantial portion of the other gases, therefrom, of means for supporting said at least one membrane (46), from which at least one portion is selected to have a Coefficient of thermal expansion that is within 10% of the thermal expansion coefficient of the at least one membrane (46, 202).

Description

DESCRIPTION

Use of means to support a selective hydrogen membrane to prevent wrinkling of said membrane

Background of the invention

Purified hydrogen is used in the manufacture of many products, including metals, edible fats and oils, and semiconductors and microelectronics. Purified hydrogen is also an important source of fuel for many energy conversion devices. For example, fuel cells use purified hydrogen and an oxidant to produce an electrical potential. Various processes and devices can be used to produce the hydrogen gas consumed by the fuel cells. However, many hydrogen production processes produce an impure hydrogen stream, which can also be referred to as a mixed gas stream containing hydrogen gas. Before delivering this stream to a fuel cell or fuel cell stack, the mixed gas stream can be purified, such as to eliminate undesirable impurities.

WO0170376 describes membrane modules that contain one or more selective hydrogen membranes, methods for preparing them, and hydrogen purification systems, fuel processors and devices containing them. The membrane modules can include one or more selective hydrogen membranes supported on a screen structure. The membrane or membranes can be adhesively mounted on the screen structure during assembly. The screen structure may include a plurality of screen members mounted adhesively together during assembly. The screen structure may include a coating.

US5376167 describes a device for separating hydrogen from gaseous mixtures containing it or for purifying gaseous hydrogen, which comprises an outer shell (2) filled with a plurality of tubes (3) made of a suitable palladium-based alloy, whose tubes are closed at one end (4). The tubes are fixed substantially tightly, on the side of the open end (5), to at least a part of a base (6) made of a metal alloy, whose composition is such that its hydrogen expansion coefficient is substantially same as the alloy of the tubes. The base can be integrally formed and made of the aforementioned alloy, or it can comprise a ring of substantially the same composition as that of the tubes that adhere thereto by means of an autogenous weld.

Summary of the Invention

The present invention relates to a use, to prevent the formation of wrinkles of at least one hydrogen selective membrane (46, 202) in a hydrogen purification device (10) comprising an enclosure (12) defining an internal compartment (18) and contains a separation unit (20), which divides the internal compartment into a mixed gas region (30) and a permeate region (32), the hydrogen purification device that is adapted to receive a stream of mixed gas (24) containing hydrogen gas (26) and other gases (28) and to produce a stream (34), which contains pure or at least substantially pure hydrogen gas, wherein the substantially pure hydrogen gas has a purity greater than 90%, and a by-product stream (36), which contains at least a substantial portion of the other gases, therefrom, of means for supporting said at least one membrane (46) of which means that at least one portion is selected p To have a coefficient of thermal expansion that is within 10% of the coefficient of thermal expansion of at least one membrane (46, 202).

The present description provides, but does not claim, hydrogen purification devices, components of hydrogen purification devices and fuel and fuel cell processing systems that include hydrogen purification devices. Hydrogen purification devices include an enclosure containing a separation unit adapted to receive a mixed gas stream containing hydrogen gas and to produce a stream containing pure or at least substantially pure hydrogen gas thereof, wherein the gas substantially pure hydrogen has a purity greater than 90%. The separation unit includes at least one hydrogen permeable and / or hydrogen selective membrane, and in some embodiments includes at least one membrane envelope that includes a pair of generally opposite membrane regions defining a collection conduit between them. and that are separated by a support.

Many other features of the present invention will become apparent to those skilled in the art by referring to the detailed description that follows and the accompanying drawing sheets describing the preferred embodiments incorporating the principles of this invention as illustrative examples. only.

Brief description of the drawings

Figure 1 is a schematic view of a hydrogen purification device.

Figure 2 is a schematic cross-sectional view of a hydrogen purification device having a flat separation membrane.

Figure 3 is a schematic cross-sectional view of a hydrogen purification device having a tubular separation membrane.

Figure 4 is a schematic cross-sectional view of another hydrogen purification device having a tubular separation membrane.

Figure 5 is a schematic cross-sectional view of another enclosure for a hydrogen purification device.

Figure 6 is a schematic cross-sectional view of another enclosure for a hydrogen purification device.

Figure 7 is a partial cross-sectional detail showing another suitable interface between the components of an enclosure for a purification device.

Figure 8 is a partial cross-sectional detail showing another suitable interface between the components of an enclosure for a purification device.

Figure 9 is a partial cross-sectional detail showing another suitable interface between the components of an enclosure for a purification device.

Figure 10 is a partial cross-sectional detail showing another suitable interface between the components of an enclosure for a purification device.

Figure 11 is a top plan view of an end plate for a hydrogen purification device that includes those shown in Figures 1-6.

Figure 12 is a cross-sectional view of the end plate of Figure 11.

Figure 13 is a top plan view of an end plate for a hydrogen purification device that includes those shown in Figures 1-6.

Figure 14 is a cross-sectional view of the end plate of Figure 13.

Figure 15 is a top plan view of an end plate for a hydrogen purification device that includes those shown in Figures 1-6.

Figure 16 is a cross-sectional view of the end plate of Figure 15.

Figure 17 is a top plan view of an end plate for a hydrogen purification device that includes those shown in Figures 1-6.

Figure 18 is a cross-sectional view of the end plate of Figure 17.

Figure 19 is a top plan view of an end plate of an enclosure for a hydrogen purification device that includes those shown in Figures 1-6.

Figure 20 is a cross-sectional view of the end plate of Figure 19.

Figure 21 is a top plan view of an end plate of an enclosure for a hydrogen purification device that includes those shown in Figures 1-6.

Figure 22 is a side elevation view of the mold inverter of Figure 21.

Figure 23 is an isometric view of the end plate of Figure 21.

Figure 24 is a cross-sectional view of the end plate of Figure 21.

Figure 25 is a side elevation view in partial cross section of an enclosure for a hydrogen purification device constructed with a pair of the end plates shown in Figures 21-24.

Figure 26 is an isometric view of another hydrogen purification device.

Figure 27 is a cross-sectional view of the device of Figure 26.

Figure 28 is a side elevation view of another end plate for a hydrogen purification device that includes those shown in Figures 1-6.

Figure 29 is a side elevation view of another end plate for a hydrogen purification device that includes those shown in Figures 1-6.

Figure 30 is a side elevation view of another end plate for a hydrogen purification device that includes those shown in Figures 1-6.

Figure 31 is a partial side elevation view of a pair of separation membranes separated by a support.

Figure 32 is an exploded isometric view of a membrane envelope that includes a support in the form of a screen structure having several layers.

Figure 33 is an exploded isometric view of another membrane envelope.

Figure 34 is an exploded isometric view of another membrane envelope.

Figure 35 is an exploded isometric view of another membrane envelope.

Figure 36 is a cross-sectional view of a cover of an enclosure for a hydrogen purification device with an illustrative membrane frame and a membrane module shown in broken lines.

Figure 37 is a top plan view of the end plate of Figure 13 with a separating membrane and an illustrative frame shown in broken lines.

Figure 38 is a top plan view of the end plate of Figure 21 with a separation membrane and an illustrative frame shown in broken lines.

Figure 39 is an exploded isometric view of another hydrogen purification device.

Figure 40 is a schematic diagram of a fuel processing system that includes a fuel processor and a hydrogen purification device.

Figure 41 is a schematic diagram of a fuel processing system that includes a fuel processor integrated with a hydrogen purification device.

Figure 42 is a schematic diagram of another fuel processor that includes an integrated hydrogen purification device.

Figure 43 is a schematic diagram of a fuel cell system that includes a hydrogen purification device.

Detailed description and best mode of the invention

A hydrogen purification device is schematically illustrated in Figure 1 and is generally indicated by 10.

The device 10 includes a body, or enclosure, 12 which defines an internal compartment 18 in which a separation unit 20 is positioned. A mixed gas stream 24 containing hydrogen gas 26 and other gases 28 is delivered to the internal compartment. More specifically, the mixed gas stream is delivered to a mixed gas region 30 of the internal compartment and comes into contact with the separation unit 20. The separation unit 20 includes any suitable structure adapted to receive the mixed gas stream and to produce a permeate or hydrogen rich stream therefrom. Stream 34 will typically contain pure or at least substantially pure hydrogen gas, wherein the substantially pure hydrogen gas has a purity greater than 90%. However, within the scope of the invention, stream 34 may at least initially also include a carrier or scanning gas component.

In the illustrated embodiment, the portion of the mixed gas stream that passes through the separation unit enters a permeate region 32 of the internal compartment. This portion of the mixed gas stream forms a hydrogen rich stream 34, and the portion of the mixed gas stream that does not pass through the separation unit forms a byproduct stream 36, which contains at least a substantial portion of The other gases. In some embodiments, the byproduct stream 36 may contain a portion of the hydrogen gas present in the mixed gas stream. The separation unit can be adapted to trap or, in any other way, retain at least a substantial portion of the other gases, which will be removed as a byproduct stream as the unit is replaced, regenerated or otherwise recharge In Figure 1, it is understood that currents 24-28 schematically represent that each of currents 24-28 can include more than one real current entering or leaving device 10. For example, device 10 can receive multiple currents from power 24, a single current 24 that is divided into multiple currents before coming into contact with the separation unit 20, or simply a single current that is delivered in the compartment 18.

The device 10 is typically operated at elevated temperatures and / or pressures. For example, the device 10 can be operated at temperatures (selected) in the range of ambient temperatures of up to 700 ° C or more. In many modalities, the selected temperature will be in the range of 200 ° C and 500 ° C, in other modalities, the selected temperature will be in the range of 250 ° C and 400 ° C and in still other modalities, the selected temperature will be 400 ° C ± or 25 ° C, 50 ° C or 75 ° C. The device 10 can be operated at pressures (selected) in the range of approximately 344.7 kPa (50 psi) and 6894.8 kPa (1000 psi) or more. In many modalities, the selected pressure will be in the range of 344.7 kPa (50 psi) and 1723.7 kPa (250 psi) or 3447.4 kPa (500 psi), in other modalities, the selected pressure will be less than 2068 , 4 kPa (300 psi) or less than 1723.7 kPa (250 psi), and even in other modalities, the selected pressure will be 1206.6 kPa (175 psi) ± 172.4 kPa (25 psi), 344, 7 kPa (50 psi) or 517.1 kPa (75 psi). As a result, the enclosure must be sufficiently sealed to reach and withstand the operating pressure.

It should be understood that as used herein with reference to operating parameters such as temperature or pressure, the term "selected" refers to threshold values or ranges of defined or predetermined values, with device 10 and any associated components that are configure to work on or within these selected values. For a further illustration, a selected operating temperature may be an operating temperature above or below a specific temperature, within a specific temperature range, or within a defined tolerance of a specific temperature, such as within 5 %, 10%, etc. of a specific temperature.

In the modes in which the device operates at a high operating temperature, heat must be applied to the device to raise the temperature of the device to the selected operating temperature. For example, this heat can be provided by any suitable heating unit 42. The illustrative examples of the heating unit 42 have been schematically illustrated in Figure 1. It should be understood that the unit 42 can take any suitable form, which itself includes the mixed gas stream 24. Illustrative examples of other suitable heating units include one or more of a resistance heater, a burner or other combustion region that produces a heated exhaust stream, heat exchange with a different heated fluid stream. to the mixed gas stream 24, etc. When a burner or other combustion chamber is used, a fuel stream is consumed and the byproduct stream 36 can form all or a portion of this fuel stream. In 42 'in Figure 1, schematic representations have been made to illustrate that the heating unit can deliver the external heated fluid current device 10, such as within a jacket that surrounds or at least partially surrounds the enclosure, by a current extending to the enclosure or through passages in the enclosure, or by conduction, such as with an electric resistance heater or other device that radiates or conducts electrically generated heat.

A suitable structure for the separation unit 20 is one or more hydrogen permeable membranes 46 and / or hydrogen selective. The membranes can be formed by any hydrogen-permeable material suitable for use in the operating environment and the parameters in which the purification device is operated 10. Examples of suitable materials for the membranes 46 include palladium and palladium alloys, and especially thin films of such metals and metal alloys. Palladium alloys have proven to be particularly effective, especially palladium with 35% by weight to 45% by weight of copper, such as a membrane containing 40% by weight of copper. These membranes are typically formed from a thin sheet that is approximately 0.0254 mm (0.001 inches) thick. However, it is within the scope of the present invention, that the membranes can be formed from other hydrogen permeable and / or hydrogen selective materials, including metals and metal alloys other than those described above, as well as materials and non-metallic compositions and that the membranes may have greater or lesser thicknesses than those described above. For example, the membrane can be made thinner, with a proportional increase in the flow of hydrogen. Examples of suitable mechanisms to reduce the thickness of the membranes include lamination, spraying and etching. A suitable etching process is described in U.S. Patent No.

6,152,995. Examples of various membranes, membrane configurations and methods for preparing them are described in U.S. Patent No. 6,221,117 and US patent application with serial number 09 / 812,499.

In Figure 2, illustrative examples of suitable configurations of the membranes 46 are shown. As shown, the membrane 46 includes a mixed gas surface 48 that is oriented to contact the mixed gas stream 24, and a surface of permeate 50, which is generally opposite surface 48. In 52 schematic representations of fasteners are also shown, which may be any suitable structure to support and / or position the membranes or other separation units within compartment 18. The patent and the Patent applications cited immediately above also describe illustrative examples of suitable fasteners 52. In 46 ', the membrane 46 is illustrated as a sheet or film. At 46 ", the membrane is supported by an underlying support 54, such as an expanded metal mesh or screen or a ceramic or other porous material. At 46"', the membrane is coated or formed on or in any other way binds to a porous member 56. It should be understood that the membrane configurations described above have been schematically illustrated in Figure 2 and are not intended to represent all possible configurations.

For example, although membrane 46 is illustrated in Figure 2 as having a flat configuration, membrane 46 may also have non-flat configurations. For example, the shape of the membrane can be defined, at least in part, by the shape of a support 54 or member 56 on which the membrane is supported and / or formed. As such, the membranes 46 may have concave, convex or other non-flat configurations, especially when the device 10 is operated at a high pressure. As another example, the membrane 46 may have a tubular configuration, as shown in Figures 3 and 4.

In Figure 3, an example of a tubular membrane is shown in which the mixed gas stream is delivered into the membrane tube. In this configuration, the interior of the membrane tube defines the region 30 of the internal compartment, and the permeate region 32 of the compartment is outside the tube. An additional membrane tube is shown in broken lines in Figure 3 to graphically represent that the device 10 may include more than one membrane and / or more than one mixed gas surface 48. The device 10 may also include more than two membranes, and that the separation and / or relative configuration of the membranes may vary.

In Figure 4, another example of a hydrogen purification device 10 including tubular membranes is shown. In this illustrated configuration, the device 10 is configured so that the mixed gas stream is delivered to the compartment 18 external to the tube or membrane tubes. In such a configuration, the mixed gas surface of a membrane tube is outside the corresponding permeate surface, and the permeate region is located within the membrane tube or tubes.

Tubular membranes can have a variety of configurations and constructions, such as those described above with respect to the flat membranes shown in Figure 2. For example, illustrative examples of various fasteners 52, brackets 54 and porous members 56 are shown in the Figures 3 and 4, which include a spring 58, which has been schematically illustrated. Tubular membranes may have a different configuration than the straight cylindrical tube shown in Figure 3. Examples of other configurations include U-shaped tubes and helical or spiral tubes.

As described, enclosure 12 defines a pressurized compartment 18 in which the separation unit 20 is positioned. In the embodiments shown in Figures 2-4, enclosure 12 includes a pair of end plates 60 that are joined by a perimeter cover 62. It should be understood that the device 10 has been schematically illustrated in Figures 2-4 to show representative examples of the general components of the device without the intention of being limited to the geometry, shape and size. For example, the end plates 60 are typically thicker than the walls of the perimeter cover 62, but this is not necessary. Similarly, the thickness of the end plates may be greater than, less than or equal to the distance between the end plates. As a further example, the thickness of the membrane 46 has been exaggerated for purposes of illustration.

In Figures 2-4, it can be seen that the mixed gas stream 24 is delivered to the compartment 18 through an inlet port 64, the hydrogen rich stream 34 (or permeate) is removed from the device 10 through one or more product ports 66, and the byproduct stream is removed from the device 10 through one or more byproduct ports 68. In Figure 2, the ports extending through several end plates are shown to illustrate that the Particular location in the enclosure 12 from which the gas streams of the device 10 are delivered to and removed may vary. One or more of the currents can be delivered or removed through the cover 62, as illustrated in broken lines in Figure 3. Ports 64-68 may include or be associated with coupling and / or flow regulating structures. Examples of these structures include one or more of the valves, flow and pressure regulators, connectors or other accessories and / or manifold assemblies that are configured to interconnect the device 10 permanently or selectively fluidly with the upstream components. and downstream. For purposes of illustration, these flow regulating and / or coupling structures are generally indicated in 70 in Figure 2. For brevity purposes, structures 70 have not been illustrated in all modalities. Instead, it should be understood that some or all of the ports for a particular mode of the device 10 may include any or all of these structures, that each port does not need to have the same structure 70, if any, and that two or more ports may, in some embodiments, share or use structure 70 collectively, such as a common collection or delivery manifold, pressure relief valve, fluid flow valve, etc.

The end plates 60 and the perimeter cover 62 are secured together by a retaining structure 72. The structure 72 can take any suitable form capable of holding the components of the enclosure 12 together in a fluid tight or substantially air tight configuration. fluids in the parameters and operating conditions in which the device 10 is used. Examples of suitable structures 72 include welds 74 and bolts 76, as shown in Figures 2 and 3. In Figure 3, the bolts 76 extending through the flanges 78 extending from the components of the enclosure 12 to be joined. In Figure 4, the bolts 76 extending through the compartment 18 are shown. It should be understood that the number of bolts may vary, and will typically include a plurality of bolts or similar fastening mechanisms that extend around the perimeter of the enclosure 18 Bolts 76 must be selected to be able to withstand the parameters and operating conditions of the device 10, which include the tension imparted to the bolts when the device 10 is pressurized.

In the lower halves of Figures 3 and 4, it is shown that the gaskets 80 illustrate that the enclosure 12 may, but not necessarily, include a seal member 82 that interconnects or encompasses the surfaces to be joined to improve the resistance to the escape of the enclosure. The seal member must be selected to reduce or eliminate leaks when used in the operating parameters and under the operating conditions of the device. Therefore, in many modalities, high pressure and / or high temperature seals must be selected. An illustrative, non-exclusive example of such a sealing structure is a graphite gasket, such as that sold by Union Carbide under the trade name GRAFOIL ™. As used herein, "seal member" and "seal member" refer to structures or materials applied to, placed between, or placed in contact with the metal end plates and the cover (or cover portions) to improve the seal established between them. The seals or other sealing members may also be used in the internal compartment 18, such as to provide seals between adjacent membranes, fluid conduits, fasteners or supports, and / or any of the foregoing with the interior surface of the enclosure 12.

In Figures 2-4, the enclosures illustrated include a pair of end plates 60 and a cover 62. With reference to Figure 4, it can be seen that the end plates include sealing regions 90, which form an interface 94 with a corresponding sealing region 92 of the cover 62. In many embodiments, the sealing region of the end plate 60 will be a perimeter region, and as such, the sealing region 90 will often be referred to herein as a perimeter region 90 of the end plate. However, as used in the present description, the perimeter region refers to the region of the end plate that generally extends around the central region and forms an interface with a portion of the cover, even if there are portions or Additional edges of the end plate that projects beyond this perimeter portion. Similarly, the sealing region 92 of the cover 62 will typically be an end region of the cover. Accordingly, the sealing region of the cover will often be referred to herein as the end region 92 of the cover. The end plates 60 may have portions projecting outwardly beyond the sealing region 90 and the interface 94 formed with the cover 62, and that cover 62 may have regions protruding beyond the end plate 60 and the interface formed with it. These portions are illustrated in broken lines in Figure 4 at 91 and 93 for graphic illustration purposes.

As an alternative to a pair of end plates 60 joined by a separate perimeter cover 62, the enclosure 12 may include a cover that integrates at least partially or with one or both of the end plates. For example, in Figure 5, a portion 63 of the cover 62 is integrally formed with each end plate 60. Described differently, each end plate 60 includes cover portions, or collars, 63 extending from the region 90 perimeter of the end plate. As shown, the cover portions include end regions 92 that intersect at an interface 94. In the illustrated embodiment, the end regions collide with each other without an overlapping region; interface 94 may have other configurations, such as those illustrated and / or described later. The end regions 92 are secured together by any suitable mechanism, such as by any of the retention structures 72 described above, and may (but not necessarily) include a seal member 82 in addition to the contact surfaces of the end regions. 92.

One benefit of the cover 62 being formed integrally with at least one of the end plates is that the enclosure has an interface less than must be sealed. This benefit can be realized by reducing leaks due to the reduced number of seals that could fail, fewer components and / or a reduced assembly time for device 10. Another example of such a construction for enclosure 12 is shown in Figure 6. , wherein the cover 62 is integrally formed with one of the end plates, with a cover portion 63 that extends integrally from the perimeter region 90 of one of the end plates. The cover portion 63 includes an end region 92 that forms an interface 94 with the perimeter region 90 of the other end plate through any suitable retaining structure 72, such as those described above. The combined end plate and the cover components shown in Figures 5 and 6 can be formed by any suitable mechanism, which includes machining of these from a solid bar or block of material. For simplicity purposes, the separation unit 20 and the input and output ports have not been illustrated in Figures 5 and 6 and only illustrative examples, not exclusive to the appropriate retention structure 72, are shown. Similar to the other enclosures illustrated and described in the present description, it should be understood that the relative dimensions of the enclosure may vary. For example, the cover portions 63 may have lengths that are longer or shorter than those illustrated in Figures 5 and 6.

Before continuing with the additional illustrative configurations for the end plates 60, it should be clarified that as used herein in relation to the enclosures of the devices 10, the term "interface" refers to the interconnection region and sealing that extends between the portions of the enclosure 12 that are formed separately and then secured together, such as (but not necessarily) by one of the retention structures 72 described above. The specific geometry and the size of the interface 94 will tend to vary, for example, depending on the size, configuration and nature of the components that join together. Therefore, the interface 94 may include a metal-on-metal seal formed between the corresponding end regions and the perimeter regions, a metal-on-metal seal formed between corresponding pairs of end regions, a metal-joint-metal seal (or other stamp member 82), etc. Similarly, the interface can have a variety of shapes, including linear, arched and rectilinear configurations that are largely defined by the shape and relative position of the components that join together.

For example, in Figure 6, an interface 94 extends between the end region 92 of the cover portion 63 and the perimeter region 90 of the end plate 60. As shown, regions 90 and 92 intersect with the parallel edges. As described, a gasket or other seal member may extend between these edges. In Figures 7 10, non-exclusive examples of additional interfaces 94 are shown. The modes of the enclosure 12 that include an interface 94 formed between adjacent cover regions may also have any of these configurations. In Figure 7, the perimeter region 90 defines a recess or corner in which the end region 92 of the cover 62 extends to form an interface 94 that extends around this corner. Also shown in Figure 7 is the central region 96 of the end plate 60, which, as illustrated, extends into the cover 62 and defines an overlapping region therewith.

In Figure 8, the perimeter region 90 defines a corner that generally opens towards compartment 18, as opposed to the corner of Figure 7, which generally opens away from compartment 18. In the configuration shown in Figure 8, the perimeter region 90 includes a collar portion 98 that extends at least partially along the outer surface 100 of the cover 62 to define an overlapping region therewith. The central region 96 of the plate 60 is shown in continuous lines that extend along the end region 92 without extending in the cover 62, in broken lines that extend in the cover 62 and in dashed lines and dots that they include an internal support 102 that extends at least partially along the inner surface 104 of the cover 60. Figures 9 and 10 are similar to Figures 7 and 8, except that the perimeter region 90 and the end region 92 they are adapted to be threadedly coupled to each other, and accordingly include the corresponding threads 106 and 108. In broken lines in Figure 9, an additional example of a configuration suitable for the perimeter region 90 of the end plate 60 is shown. As shown, the outer edge 110 of the end plate does not extend radially (or outward) to or beyond the outer surface of the cover 62.

It should be understood that any of these interfaces can be used with an enclosure constructed as described in the present description. However, for brevity purposes, each mode of enclosure 12 will not be shown with each of these interfaces. Therefore, although the end plates described below shown in Figures 11-31 are shown with the configuration of the interface of Figure 7, it is within the scope of the invention that the end plates and corresponding covers can be configured to have any of the interfaces described and / or illustrated in the present description, as well as the configuration of the integrated cover described and illustrated with respect to Figures 5 and 6. Similarly, it should be understood that the devices may have any of the enclosure configurations, interface configurations, retention structure configurations, separation unit configurations, coupling structures and / or flow regulators, seal member configurations and port configurations, described and / or incorporated herein. Similarly, although the following end plate configurations are illustrated with circular perimeters, the end plates can be configured to have perimeters with any other geometric configuration, which includes arched, rectilinear and angular configurations, as well as combinations thereof.

As described, the dimensions of device 10 and enclosure 12 may also vary. For example, an enclosure designed to accommodate tubular separation membranes may need to be longer (i.e. have a greater distance between the end plates) than an enclosure designed to accommodate flat separation membranes to provide a comparable amount of surface area of membrane exposed to the mixed gas stream (ie, the same amount of effective surface area of the membrane). Similarly, an enclosure configured to accommodate flat separation membranes may tend to be wider (i.e. have a larger measured cross-sectional area generally parallel to the end plates) than an enclosure designed to accommodate tubular separation membranes. However, it should be understood that none of these relationships is necessary, and that the specific size of the device and / or the enclosure may vary. Factors that may affect the specific size of the enclosure include the type and size of the separation unit to be housed, the operating parameters in which the device will be used, the flow rate of the mixed gas stream 24 , the shape and configuration of the devices, such as heating units, fuel processors and the like with which or within which the device will be used, and to some extent, user preferences.

As described above, hydrogen purification devices can operate at elevated temperatures and / or pressures. Both of these operating parameters can affect the design of the enclosures 12 and other components of the devices. For example, consider a hydrogen purification device 10 operated at a selected operating temperature above an ambient temperature, such as a device operating at 400 ° C. As an initial matter, the device, which includes the enclosure 12 and the separation unit 20, must be constructed from a material that can withstand the selected operating temperature, and especially for prolonged periods of time and / or with repeated heating cycles and cooling Similarly, materials that are exposed to gas streams are preferably not reactive or, at least, do not react negatively with gases. An example of a suitable material is stainless steel, such as Type 304 stainless steel, although others may be used.

In addition to the thermal and reactive stability described above, the control device 10 at a selected high temperature requires one or more heating units 42 to heat the device to the selected operating temperature. When the device is initially operated from an off or unheated state, there will be an initial start-up or preheat period in which the device is heated to the temperature of selected operation. During this period, the device can produce a hydrogen-rich stream that contains more than an acceptable level of the other gases, a hydrogen-rich stream that has a reduced flow rate compared to the by-product stream or streams (which means that a higher percentage of hydrogen gas is depleted as a byproduct instead of a product), or even no hydrogen rich stream. In addition to the time to heat the device, the heat or thermal energy required to heat the device to the selected temperature must also be considered. The heating unit or units may increase the operating cost, the cost of the materials and / or the cost of the device equipment. For example, a simplified end plate 60 is a relatively thick slab that has a uniform thickness. In fact, Type 304 stainless steel plates having a uniform thickness of 12.7 mm (0.5 ") or 19.05 mm (0.75 inches) have proven effective in supporting and resisting the parameters and conditions of operation of the device 10. However, the dimensions of these plates add considerable weight to the device 10, and in many modalities require considerable thermal energy to be heated to the selected operating temperature. As used herein, the term " uniform thickness "refers to devices that have a constant or at least substantially constant thickness, which includes those that deviate in thickness by a few (less than 5%) along their lengths. On the contrary, and as used In the present description, a "variable thickness" will refer to a thickness that varies at least 10%, and in some modalities at least 25%, 40% or 50%.

The pressure at which the device 10 is operated can also affect the design of the device 10, which includes the enclosure 12 and the separation unit 20. Consider, for example, a device operating at a selected pressure of 1206.6 kPa (175 psi). The device 10 must be constructed to be able to withstand the voltages encountered when operating at the selected pressure. This resistance requirement affects not only the seals formed between the components of the enclosure 12, but also the stresses imparted to the components themselves. For example, the deflection or other deformation of the end plates and / or the cover can cause the gases inside the compartment 18 to escape from the enclosure. Similarly, the deviation and / or deformation of the components of the device can also cause an involuntary mixing of two or more of the gas streams 24, 34 and 36. For example, an end plate can deform plastic or elastically when subjected to the operating parameters under which the device 10 is used. The plastic deformation results in a permanent deformation of the end plate, whose disadvantage seems quite evident. However, elastic deformation can also impede the operation of the device, because deformation can result in internal and / or external leaks. More specifically, deformation of end plates or other components of enclosure 12 may allow gases to pass through regions where previously sealed seals existed. As described, the device 10 may include seals or other seal members to reduce the tendency of these seals to seep, however, the seals have a finite size within which they can effectively prevent or limit leaks between opposing surfaces. . For example, internal leaks may occur in modalities that include one or more membrane wraps or compressed membrane plates (with or without joints) between the end plates. As the end plates deform and deviate from each other, the plates and / or joints may in those regions not be under the same tension or compression that existed before deformation. The gaskets, or gasket plates, can be located between a membrane envelope and adjacent feeding plates, end plates and / or other adjacent membrane envelopes. Similarly, gaskets or gasket plates can also be positioned within a membrane envelope to provide additional leak prevention within the envelope.

In view of the above, it can be seen that there are two or three competitive factors that must be weighted with respect to the device 10. In the context of the enclosure 12, the enclosure heating requirements will tend to increase as the materials used to form the enclosure Thicken However, to a certain extent, the use of thicker materials can increase the strength of the enclosure, it can also increase the heating and material requirements, and in some modalities they actually produce regions where higher stresses are imparted compared to a thinner enclosure. The areas to be monitored on an end plate include the deviation of the end plate, especially in the perimeter regions that form the interface (s) 94, and the stresses imparted to the end plate.

Consider, for example, a circular end plate formed of Type 304 stainless steel and having a uniform thickness of 19.05 mm (0.75 inches). Such end plate weighs 3.4 kg (7.5 pounds). A hydrogen purification device containing this end plate was exposed to operating parameters of 400 ° C and 1206.6 kPa (175 psi). Maximum stresses of 178.6 mPa (25,900 psi) were imparted to the end plate, with a maximum deviation of 0.11 mm (0.0042 inches) and a deviation in the perimeter region 90 of 0.064 mm (0.0025 inches) ).

Another end plate 60 constructed in accordance with the present invention is shown in Figures 11 and 12 and is generally indicated at 120. As shown, the end plate 120 has inner and outer surfaces 122 and 124. The inner surface 122 includes the central region 96 and the perimeter region 90. The outer surface 124 has a central region 126 and a perimeter region 128, and in the embodiment illustrated, the plate 120 has a perimeter 130 that extends between the perimeter regions 90 and 128 of the interior and exterior surfaces. As described above, the perimeter region 90 may have any of the configurations illustrated or described above, which includes a configuration in which the sealing region is located at least partially or completely along the perimeter 130. In the illustrated embodiment, the perimeter 130 has a circular configuration. However, the shape may vary, such as, to include rectilinear and other arched, geometric, linear and / or corner configurations.

However, unlike the end plates illustrated above, the central region of the end plate has a variable thickness between its inner and outer surfaces, which may be better seen in Figure 12. Unlike a slab of uniform material , the outer surface of the plate 120 has a central region 126 that includes an outer cavity, or removed region, 132 that extends towards the plate and generally towards the central region 96 on the inner surface 122. Otherwise described, the plate end has a non-planar outer surface, and more specifically, an outer surface in which at least a portion of the central region extends towards the corresponding central region of the inner surface of the end plate. Region 132 reduces the total weight of the end plate compared to a similarly constructed end plate that does not include region 132. As used herein, the deleted region 132 is intended to exclude ports or other holes that They extend completely through the end plates. Instead, region 132 extends towards the end plate, but not through it.

A reduction in weight means that a purification device 10 that includes the end plate will be lighter than a corresponding purification device that includes a similarly constructed end plate formed without region 132. With the weight reduction also comes a corresponding reduction in the amount of heat (thermal energy) that must be applied to the end plate to heat the end plate to a selected operating temperature. In the illustrated embodiment, the region 132 also increases the surface area of the outer surface 124. Increasing the surface area of the end plate compared to a corresponding end plate may, but not necessarily in all embodiments, increase the surface area. Heat transfer of the end plate, which in turn, can reduce the heating requirements and / or the time of a device containing the end plate 120.

In some embodiments, the plate 120 can also be described as having a cavity corresponding to, or including, the region of maximum tension in an end plate constructed in a similar manner in which the cavity was not present. Accordingly, when exposed to the same parameters and operating conditions, lower voltages will be imparted to the end plate 120 than to a solid end plate formed without region 132. For example, in the solid end plate with a uniform thickness, the region of maximum tension is produced within the portion of the end plate occupied by the region removed 132 in the end plate 120. Accordingly, an end plate with region 132 may be described additionally or alternatively as that it has a tension reduction structure 134 in which a maximum tension area that would otherwise be imparted to the end plate has been removed.

For comparison purposes, consider an end plate 120 that has the configuration shown in Figures 11 and 12, formed from Type 304 stainless steel and has a diameter of 165.1 mm (6.5 inches). This configuration corresponds to the maximum plate thickness of 19.05 mm (0.75 inches) and a deleted region 132 having a length and width of 76.2 mm (3 inches). When used in a device 10 operating at 400 ° C and 1206.6 kPa (175 psi), the plate 120 has a maximum tension imparted to it of 248.2 mPa (36000 psi), a maximum deviation of 0.1981 mm (0.0078 inches), a displacement of 0.1397 mm (0.0055 inches) in the perimeter region 90, and a weight of 2.59 kg (5.7 pounds). It should be understood that the dimensions and properties described above are intended to provide an illustrative example of the combinations of weight, tension and displacement experienced by the end plates described in the present description and that the shape of the specific perimeter, the construction materials, the Perimeter size, thickness, the shape of the removed region, the depth of the deleted region and the perimeter of the deleted region may vary.

In Figure 11, it can be seen that region 132 (and / or tension reduction structure 134) has a generally square or rectilinear configuration measured transversely to surfaces 122 and 124. As described, other geometries and dimensions can be used and be within the scope of the invention. To illustrate this point, variations of the end plate 120 are shown in Figures 13-16 and generally indicated in 120 'and 120 ". In these Figures, the region 132 having a circular perimeter is shown, with the dimensions of the region that are smaller in Figures 13 and 14 than in Figures 15 and 16.

For comparison purposes, consider an end plate 120 that has the configuration shown in Figures 13 and 14 and that has the same construction materials, perimeter and thickness as the end plate shown in Figures 11 and 12. Instead of the generally square deleted region of Figures 11 and 12, however, the end plate 120 'has a region removed with a generally circular perimeter and a diameter of 82.55 mm (3.25 inches). The end plate 120 'weighs the same as the end plate 120, but has reduced the maximum tension and deviations. More specifically, while the end plate 120 had a maximum tension greater than 241.3 mPa (35,000 psi), the end plate 120 'had a maximum tension less than 206.8 mPa (30,000 psi), and in the illustrated configuration less than 172.4 mPa (25 000 psi), when subjected to the operating parameters described above with respect to plate 120. In fact, plate 120 'demonstrated approximately a 35% reduction in maximum tension in comparison with plate 120. The maximum and perimeter region deviations of plate 120 'were also smaller than those of plate 120, with a maximum measured deviation of 0.178 mm (0.007 inches) and a measured deviation in the perimeter region 90 0.127 mm (0.0050 inches).

The end plate 120 ", shown in Figures 15 and 16 is similar to the end plate 120 ', except that region 132 (and / or structure 134) has a diameter of 95.3 mm (3, 75 inches) instead of 82.6 mm (3.25 inches) This change in the size of the removed region decreases the weight of the end plate to 2.4 kg (5.3 pounds) and produces The same maximum deviation. The 120 "end plate also demonstrated a maximum tension of less than 172.4 mPa (25 000 psi), although approximately 5% greater than that of the 120 '(170.3 mPa (24 700 psi) end plate, in comparison with 162.0 mPa (23,500 psi). In the perimeter region 90, end plate 120 "exhibited a maximum deviation of 0.173 mm (0.0068 inches).

In Figures 13-16, illustrative port configurations have been shown. In Figures 13 and 14, a port 138 is shown in dashed lines extending from the inner surface 122 through the end plate to the outer surface 124. Accordingly, with such a configuration, a current is delivered or removed. of gas through the outer surface of the end plate of the device 10. In such a configuration, the fluid conduits and / or the coupling and / or flow regulator structure 70 will typically be projected from the outer surface of the plate end 124. Another suitable configuration is indicated at 140 in broken lines in Figures 15 and 16. As shown, port 140 extends from the inner surface of the end plate and then through the perimeter 130 instead of the surface exterior 124. Accordingly, port 140 allows gas to be delivered or removed from the perimeter of the end plate instead of the outer surface of the end plate. It should be understood that ports 64-68 may have these configurations illustrated by ports 138 and 140. Of course, ports 64-68 may also have any other suitable port configuration, which includes a port that extends through the cover. 62 or a portion of the cover. For simplicity, the ports will not be illustrated on many of the end plates described below, as they were not illustrated in Figures 5 and 6.

Also shown in broken lines in Figures 13-15 are guide structures 144. Guide structures 144 extend in compartment 18 and provide supports that can be used to position and / or align the separation unit 20, such as membranes 46. In some embodiments, guide structures 144 may form fasteners 52 for the separation unit. In other embodiments, the device includes fasteners other than the guide structures 144. The guide structures can be used with any of the end plates illustrated, incorporated and / or described in the present description, regardless of whether any such structure is shown guide in a particular drawing figure. However, it should also be understood that hydrogen purification devices can be formed without guide structures 144. In the embodiments of device 10 that include guide structures 144 extending in or through compartment 18, the amount of such structures may vary. from a single support to two or more supports. Similarly, while guide structures 144 have been illustrated as cylindrical ribs or projections, other shapes and configurations can be used.

The guide structures 144 can be formed from the same materials as the corresponding end plates. Additionally or alternatively, the guide structures may include a coating or layer of a different material. The guide structures 144 can be formed either separately from the end plates and subsequently attached to them, or formed integrally with them. The guide structures 144 can be coupled to the end plates by any suitable mechanism, including joining the guide structures to the inner surfaces of the end plates, inserting the guide structures into holes that partially extend through the plates end from the inner surfaces thereof, or insert the guide structures through the holes that extend completely through the end plates. In embodiments in which the end plates include holes that extend completely through the end plates (which are illustrated graphically for illustrative purposes in 146 in Figure 14), the guide structures can be subsequently attached to the plates. extreme. Alternatively, the guide structures can be inserted through the compartment 18 until the separation unit is properly assigned and secured therein, and then the guide structures can be removed and the holes sealed (for example, by welding) to avoid leaks

In Figures 17 and 18, another end plate 60 constructed in accordance with the present invention is shown and generally indicated at 150. Unless otherwise specified, it should be understood that end plates 150 may have any of members, sub-members and variations as any of the other end plates shown, described and / or incorporated in the present description. Similar to end plate 120 ', plate 150 includes an outer surface 124 with a removed region 132 (and / or tension reduction structure 134) having a circular perimeter with a diameter of 82.6 mm (3.25 inches). The outer surface 124 further includes a removed outer region 152 which extends from the central region 126 to the perimeter portion 128. The removed outer region 152 decreases in thickness as it approaches perimeter 130. In the embodiment illustrated, region 152 It has a generally linear reduction in thickness, although other linear and arched transitions can be used. For example, a variation of end plate 150 is shown in Figures 19 and 20 and is generally indicated at 150 '. The end plate 150 'also includes the removed central and outer regions 132 and 152, with the outer surface 124 having a generally semitoroidal configuration since it extends from the central region 126 to the perimeter region 128. To demonstrate that the size of region 132 (which will also be referred to as a deleted central region, such as when incorporated into an end plate that also includes a removed outer region), may vary, end plate 150 'includes a deleted central region having a diameter of 76.2 mm (3 inches).

For comparison purposes, both end plates 150 and 150 'have reduced weights compared to end plates 120, 120' and 120 ". Plate 150 weighed 2.1 kg (4.7 pounds) and plate 150 ' Weighed 2.3 kg (5.1 lbs.) Both 150 and 150 'end plates experienced maximum stresses of 172.4 mPa (25,000 psi) or less when subjected to the operating parameters described above (400 ° C and 1206.6 kPa (175 psi)), with 150 'plate which has 5% less tension than the 150 plate (163.8 mPa (23 750 psi) compared to 172.4 mPa (25 000 psi)). The maximum deviation of the plates was 0.249 mm (0.0098 inches) and 0.203 mm (0.008 inches), respectively, and the displacement in the 90 perimeter regions was 0.155 mm (0.0061 inches) and 0.155 mm (0.0059 inches) ), respectively.

Another end plate60 is shown in Figures 21-24 and generally indicated as 160. Unless otherwise specified, the end plate 160 may have the same members, sub members and variations as the other end plates illustrated and / or described in this description. The end plate 160 may be referred to as an armature reinforced end plate because it includes an armature assembly 162 extending from the outer surface of the end plate 124. As shown, the end plate 160 has a plate base 164 with a generally flat configuration, similar to the end plates shown in Figures 2-5. However, the armature assembly 162 allows, but does not require, that the base plate can have a thinner construction and, at the same time, provide comparable maximum but not reduced stresses and deflections. Any of the other end plates illustrated and / or described in the present description may also include an armature assembly 162.

The armature assembly 162 extends from the outer surface 124 of the base plate 164 and includes a plurality of projecting ribs 166 extending from the outer surface 124. In Figures 21-24, it can be seen that the ribs 166 are radially separated around surface 124. Nine ribs 166 are shown in Figures 21 and 23, but it is within the scope of the invention that the armature assembly 162 can be formed with more or less ribs. Similarly, in the illustrated embodiment, ribs 166 have arcuate configurations and include flanges 168 extending between ribs and surface 124. Flanges 168 can also be described as heat transfer fins because they add a considerable area of heat transfer to the end plate. The armature assembly 162 further includes a tension collar 170 that interconnects the ribs. As shown, the collar 170 generally extends parallel to the base plate of the surface 164 and has an open central region 172. The collar 170 can be formed with a closed central portion or that projects internally or externally. To illustrate this point, members 174 are shown in broken lines that extend through collar 170 in Figure 21. Similarly, collar 170 may have different configurations than the circular configuration shown in Figures 21 24. As a additional alternative, the base plate 164 has been indicated in partial broken lines in Figure 22 to graphically illustrate that the base plate can have a variety of configurations, such as those described and illustrated in the present description, which includes the configuration shown if the discontinuous region is removed.

The end plate 160 may additionally or alternatively be described as having a support 170 that extends in a separate relationship beyond the outer surface 124 of the base plate 164 and that is adapted to provide additional stiffness and / or resistance to the motherboard Still another additional or alternative description of the end plate 160 is that the end plate includes a heat transfer structure 162 that extends away from the outer surface of the base plate, and that the heat transfer structure includes a surface 170 which is separated from the surface 124 so that a stream of hot fluid can pass between the surfaces.

The armature assembly 162 can also be referred to as an example of a deviation reduction structure because it reduces the deviation that, in any other way, would occur if the base plate 164 were formed without the armature assembly. Similarly, armature assembly 162 may also provide another example of a stress reduction structure because it reduces the maximum stresses that would otherwise be imparted to the base plate. In addition, the open design of the reinforcement assembly increases the heat transfer area of the motherboard without adding significant weight to the motherboard.

Continuing with the previous comparisons between the end plates, the plate 160 was subjected to the same operating parameters as the end plates described above. The maximum stresses imparted to the motherboard 164 were 68.9 mPa (10,000 psi) or less. Similarly, the maximum deviation of the base plate was only 0.155 mm (0.0061 inches), with a deviation of 0.142 mm (0.0056 inches) in the perimeter region 90. It should be noted that the base plate 160 achieved this significant reduction in maximum tension while weighing only 1.50 kg (3.3 pounds). Similarly, the base plate 164 experienced a smaller maximum displacement and a comparable or reduced perimeter displacement, but had a base plate only 6.35 mm (0.25 inches) thick. Of course, the plate 160 can be constructed with thicker base plates, but the tested plate proved to be strong and rigid enough under the operating parameters with which it was used.

As described, enclosure 12 may include a pair of end plates 60 and a perimeter cover. In Figure 25, an example of an enclosure 12 formed with a pair of end plates 160 is shown for illustrative purposes and is generally indicated at 180. Although enclosure 180 has a pair of end plates reinforced with reinforcements 160, an enclosure It can have end plates that have different constructions and / or configurations. In fact, in some operating environments it may be beneficial to form enclosure 12 with two different types of end plates. In others, it may be beneficial for the end plates to have the same construction.

In Figures 26 and 27, another example of an enclosure 12 is shown and generally indicated in 190 and includes end plates 120 "." End plate 120 "has a configuration similar to that of Figures 13- 16, except that the deleted region 132 that has a diameter of 101.6 mm (4 inches) is shown to illustrate even more than the shape and the Deleted region size may vary. Both end plates include cover portions 63 that extend integrally therefrom to illustrate that any of the end plates illustrated and / or described herein may include a cover portion 63 that extends integrally therefrom. To illustrate that any of the end plates described and / or illustrated in the present description may also include reinforcement assemblies (or heat transfer structure) 162 and / or protruding supports 170 or deviation reduction structure, the members 194 projecting through the removed region 132 in a configuration separate from the outer surface 124 of the end plate. Enclosure 12 may include stress reduction and / or deflection structures that extend into compartment 18 as opposed to, or in addition to, corresponding structures that extend from the outer surface of the end plates. In Figures 28-30, end plates 60 are shown illustrating examples of these structures. For example, in Figure 28, the end plate 60 includes a removed region 132 that extends toward the end plate from the inner surface 122 of the end plate. It should be understood that region 132 may have any of the configurations described and / or illustrated in the present description with respect to the removed regions that extend from the outer surface of a base plate. Similarly, in broken lines at 170 in Figure 28, supports are shown that extend through region 132 to provide additional support and / or rigidity to the end plate. In Figure 29, the end plate 60 includes internal brackets 196 that are adapted to extend in the compartment 18 to interconnect the end plate with the corresponding end plate at the other end of the compartment. As described, guide structures 144 may form the support. In Figure 30, an internally protruding armature assembly 162 is shown. The device 10 may include end plates 60 that exhibit at least one of the following properties or combinations of properties compared to an end plate formed by a solid slab of uniform thickness of the same material as the end plate 60 and exposed to the same operating parameters:

an outstanding armor assembly;

a support that stands out internally;

a support that protrudes externally;

an external region removed;

an internal region removed;

an integral cover portion;

an integral cover;

a reduced mass and a reduced maximum tension;

a reduced mass and a reduced maximum displacement;

a reduced mass and reduced perimeter displacement;

a reduced mass and an increased heat transfer area;

a reduced mass and internally protruding supports;

a reduced mass and externally protruding supports;

a reduced maximum tension and a reduced maximum displacement;

a reduced maximum tension and a reduced perimeter offset;

a reduced maximum voltage and an increased heat transfer area;

a reduced maximum tension and an outstanding reinforcement assembly;

a reduced maximum voltage and a region removed;

a reduced maximum displacement and a reduced perimeter displacement;

a reduced maximum displacement and an increased heat transfer area;

a reduced perimeter offset and an increased heat transfer area;

a reduced perimeter offset and an outstanding armor assembly;

a reduced perimeter offset and a region removed;

a mass / maximum displacement ratio that is less than 0.0987 kg / Pa (1500 lb / psi);

0,0329 kg/Pa (500 lb/psi); una relación de desplazamiento masa/máximo que es menor que 0,132 kg/Pa (2000 lb/psi);a mass / maximum displacement ratio that is less than 0.0658 kg / Pa (1000 lb / psi); a mass / maximum displacement ratio that is less than 0.0493 kg / Pa (750 lb / psi); a mass / maximum displacement ratio that is less than

0.0329 kg / Pa (500 lb / psi); a mass / maximum displacement ratio that is less than 0.132 kg / Pa (2000 lb / psi);

a mass / perimeter displacement ratio that is less than 0.0987 kg / Pa (1500 lb / psi);

a mass / perimeter displacement ratio that is less than 0.0658 kg / Pa (1000 lb / psi);

a mass / perimeter displacement ratio that is less than 0.0526 kg / Pa (800 lb / psi);

a mass / maximum displacement ratio that is less than 0.0395 kg / Pa (600 lb / psi);

a cross-sectional area / mass ratio that is at least 8534.0 mm2 / kg (6 in2 / pound);

a cross-sectional area / mass ratio that is at least 9956.3 mm2 / kg (7 in2 / pound); I

a cross-sectional area / mass ratio that is at least 14223.3 mm2 / kg (10 in2 / pound).

As described, the enclosure 12 contains an internal compartment 18 housing the separation unit 20, such as one or more separation membranes 46, which are supported within the enclosure by a suitable fastener 52. In the illustrative examples shown in the Figures 2 and 4, the separation membranes 46 were represented as independent flat or tubular membranes. The membranes can be arranged in pairs that define the permeate region 32 between them. In such a configuration, the pairs of membranes can be referred to as a membrane envelope, in the sense that they define a common permeate region 32 in the form of a collection conduit, or flow path, which extends between them and from which the hydrogen rich stream 34 can be collected.

An example of a membrane wrap is shown in Figure 31 and is generally indicated at 200. It should be understood that the pairs of membranes can take a variety of suitable shapes, such as flat wrap and tubular wrap. Similarly, membranes can be supported independently, such as with respect to an end plate or around a central passage. For purposes of illustration, the following description and associated illustrations will describe that the separation unit includes one or more envelopes of the membrane 200. It should be understood that the membranes that form the envelope can be two separate membranes, or they can be a single folded membrane , wound or configured in any other way to define two membrane regions, or surfaces, 202 with permeate surfaces 50 that are oriented towards each other to define a conduit 204 between which hydrogen-rich permeate gas can be collected and extracted. The conduit 204 may itself form the permeate region 32, or a device 10 according to the present invention may include a plurality of membrane sheaths 200 and the corresponding conduits 204 that collectively define the permeate region 32.

To support the membranes against high feed pressures, a support 54 is used. The support 54 must allow the gas penetrating through the membranes 46 to flow through it. The support 54 includes the surfaces 211 against which the permeate surfaces 50 of the membranes are supported. In the context of a pair of membranes that form a membrane envelope, the support 54 can also be described as defining the collection conduit 204. In the conduit 204, the permeated gas can preferably flow both transversely and parallel to the surface of the membrane through which the gas passes, as schematically illustrated in Figure 31. The permeate gas, which is at least substantially pure hydrogen gas, wherein the substantially pure hydrogen gas has a purity greater than 90% , then it can be collected or removed in any other way from the envelope to form a stream rich in hydrogen 34. Because the membranes rest on the support, it is convenient that the support does not obstruct the flow of gas through the selective membranes of hydrogen. The gas that does not pass through the membranes forms one or more by-product streams 36, as schematically illustrated in Figure 31.

An example of a suitable support 54 for membrane sheaths 200 is shown in Figure 32 in the form of a screen structure 210. The screen structure 210 includes multiple screen members 212. In the illustrated embodiment, the screen members they include a thick mesh screen 214 interspersed between the fine mesh screens 216. It should be understood that the terms "thin" and "thick" are relative terms. Preferably, the outer screen members are selected to support the membranes 46 without perforating the membranes and without having sufficient openings, edges or other projections that can pierce, weaken or otherwise damage the membrane in the operating conditions with which it operates. the device 10. Because the screen structure must provide a permeate gas flow generally parallel to the membranes, it is convenient to use a relatively thicker internal screen member to provide improved or larger parallel flow ducts. In other words, the finer mesh screens provide better protection for the membranes, while the thicker mesh screen provides a better flow generally parallel to the membranes and, in some modalities, can be selected to be more rigid or less flexible. , than the finest mesh screens.

The screen members may be similar or of the same construction, and more or less screen members may be used than is shown in Figure 32. Preferably, the support 54 is formed of a corrosion resistant material that will not harm the operation of the hydrogen purification device and other devices with which the device 10 is used. Examples of suitable materials for the metal screen members include stainless steels, titanium and alloys thereof, zirconium and alloys thereof, resistant alloys to corrosion, which include Inconel ™ alloys, such as 800H ™ and Hastelloy ™ alloys, and copper and nickel alloys, such as Monel ™. Hastelloy ™ and Inconel ™ alloys are nickel based alloys. Inconel ™ alloys typically contain nickel alloyed with chromium and iron. Monel ™ alloys are typically nickel, copper, iron and manganese alloys. Additional examples of structure for the supports 54 include porous ceramic, porous carbon, porous metal, ceramic foam, carbon foam and metallic foam, either alone or in combination with one or more screen members 212. As another example, some or All screen members can be formed from expanded metal instead of a woven mesh material.

During the fabrication of the membrane wraps, adhesive can be used to secure the membranes 46 to the screen structure and / or to secure the components of the screen structure 210 together, as described in more detail in the patent application. United States with serial number 09 / 812,499. For illustration purposes, the adhesive is generally indicated on broken lines at 218 in Figure 32. An example of a suitable adhesive is sold by 3M under the trade name SUPER 77. Typically, the adhesive is removed at least substantially, if not completely , after fabrication of the membrane wrap so as not to interfere with the permeability, selectivity and flow paths of the membrane envelopes. An example of a suitable method for removing adhesive from membranes and / or screen structures or other supports is by exposure to oxidizing conditions before the initial operation of the device 10. The objective of oxidative conditioning is to burn the adhesive without excessively oxidizing the palladium alloy membrane. A suitable procedure for such oxidation is described in the previous patent application.

The supports 54, which include the screen structure 210, can include a coating 219 on the surfaces 71 that fit the membranes 46, as indicated in the dashed lines and dots in Figure 32. Examples of suitable coatings include aluminum oxide, tungsten carbide, tungsten nitride, titanium carbide, titanium nitride and mixtures thereof. These coatings are generally characterized by being thermodynamically stable with respect to decomposition in the presence of hydrogen. Suitable coatings are formed from materials, such as oxides, nitrides, carbides or intermetallic compounds, which can be applied as a coating and which are thermodynamically stable with respect to decomposition in the presence of hydrogen under the operating parameters (temperature, pressure , etc.) under which the hydrogen purification device will work. Suitable methods for applying such coatings to the screen or to the expanded metal screen member include chemical vapor deposition, sputtering, thermal evaporation, thermal spraying and, in the case of at least aluminum oxide, metal deposition ( for example, aluminum) followed by oxidation of the metal to give aluminum oxide. In at least some embodiments, the coatings can be described as preventing intermetallic diffusion between the selective hydrogen membranes and the screen structure.

The hydrogen purification devices 10 described, illustrated and / or incorporated in the present description may include one or more membrane envelopes 200, typically together with suitable inlet and outlet ports through which the mixed gas stream is delivered and of which the currents rich in hydrogen and by-products are eliminated. In some embodiments, the device may include a plurality of membrane envelopes. When the separation unit includes a plurality of membrane wraps, it can include fluid conduits that interconnect the wraps, such as to deliver a mixed gas stream thereto, to extract the hydrogen-rich stream from them and / or to remove the gas that does not pass through the membranes of the mixed gas region 30. When the device includes a plurality of membrane envelopes, permeate stream, byproduct stream, or both, from a first shell of The membrane can be sent to another membrane wrap for further purification. The envelope or the plurality of envelopes and ports, supports, associated conduits and the like can be referred to as membrane module 220.

The amount of membrane sheaths 200 used in a particular device 10 depends to some extent on the feed rate of the mixed gas stream 24. For example, a membrane module 220 containing four shells 200 has proven effective for a mixed gas stream delivered to device 10 at a flow rate of 20 liters / minute. As the flow rate increases, the amount of membrane envelopes may increase, such as in a generally linear relationship. For example, a device 10 adapted to receive the mixed gas stream 24 at a flow rate of 30 liters / minute may preferably include six membrane envelopes. However, these illustrative amounts of envelopes are provided for illustrative purposes, and a greater or lesser amount of envelopes can be used. For example, factors that may affect the amount of envelopes that will be used include the flow of hydrogen through the membranes, the effective surface area of the membranes, the flow regime of the mixed gas stream 24, the desired purity of the hydrogen-rich stream 34, the desired efficiency at which hydrogen gas is removed from the mixed gas stream 24, the user's preferences, the available dimensions of the device 10 and the compartment 18, etc.

Preferably, but not necessarily, the screen structure and the membranes that are incorporated into a membrane wrap 200 include frame members 230, or plates, which are adapted to seal, support and / or interconnect the membrane envelopes. An illustrative example of suitable frame members 230 is shown in Figure 33. As shown, the screen structure 210 fits within a frame member 230 in the form of a permeate frame 232. The screen structure and the frame 232 may collectively be referred to as a screen plate or permeate plate 234. When the screen structure 210 includes expanded metal members, the expanded metal screen members may fit either within the permeate frame 232 or extend at least partially over the frame surface. Additional examples of frame members 230 include support frames, feed plates and / or gaskets. These frames, joints or other support structures can also define, at least in part, the fluid conduits that interconnect the membrane envelopes in an embodiment of the separation unit 20 containing two or more membrane envelopes. Examples of suitable gaskets are flexible graphite gaskets, which include those sold under the trade name GRAFOIL ™ by Union Carbide, although other materials may be used, such as depending on the operating conditions in which the device 10 is used.

Continuing with the previous illustration of the illustrative frame members 230, the permeate joints 236 and 236 'are attached to the permeate frame 232, preferably but not necessarily, by using another thin application of adhesive. Next, the membranes 46 rest against the screen structure 210 and / or join the screen structure 210 by using a thin application of adhesive, such as spraying or otherwise applying the adhesive to any of the membranes and / or screen structure. Care should be taken to ensure that the membranes are flat and firmly attached to the corresponding screen member 212. The feed plates, or joints, 238 and 238 'are optionally joined to the joints 236 and 236', such as, by means of the use of another thin application of adhesive. The resulting membrane wrap 200 is then positioned within the compartment 18, such as by a suitable fastener 52. Optionally, two or more membrane envelopes can be stacked or otherwise supported together within the compartment 18.

As an additional alternative, each membrane 46 can be fixed to a frame member 230, such as a metal frame 240, as shown in Figure 34. If so, the membrane is fixed to the frame, for example, by ultrasonic welding or other suitable joining mechanism. The membrane frame assembly can, but is not required, join screen structure 210 by using adhesive. Other examples of joining mechanisms that achieve gas-tight seals between the plates that form the membrane wrap 200, as well as between the membrane wraps, include one or more brazing, sealing and welding. The membrane and the attached frame can be collectively referred to as a membrane plate 242. It is within the scope of the invention that the various frames described in the present description do not all have to be formed from the same materials and / or that the frames can not have the same dimensions, such as the same thicknesses. For example, permeate and feed frames can be formed of stainless steel or other suitable structural member, while the membrane plate can be formed of a different material, such as copper, alloys thereof and other materials described in the patents and previous requests. Additionally and / or alternatively, the membrane plate may, but is not required to be, thinner than the feed and / or permeate plates.

For illustrative purposes, a suitable geometry of the fluid flow through the envelope of the membrane 200 is described with respect to the embodiment of the envelope 200 shown in Figure 33. As shown, the mixed gas stream 24 is delivered to the membrane envelope and comes into contact with the outer surfaces 50 of the membranes 46. The hydrogen-rich gas that penetrates through the membranes enters the collection conduit 204. The collection conduit is in continuous communication with the ducts 250 through which the permeate stream can be extracted from the membrane envelope. The portion of the mixed gas stream that does not pass through the membranes flows to a conduit 252 through which this gas can be extracted as a byproduct stream 36. In Figure 33, a single byproduct conduit 252 is shown, while a pair of ducts 252 is shown in Figure 34 to illustrate that any of the ducts described in the present description may alternatively include more than one fluid passage. It should be understood that the arrows used to indicate the flow of streams 34 and 36 have been schematically illustrated, and that the direction of flow through conduits 250 and 252 may vary, such as, depending on the configuration of a wrapper the particular membrane 200, module 220 and / or device 10.

In Figure 35, another example of a suitable membrane wrap 200 is shown. To graphically illustrate that the end plates 60 and the cover 62 can have a variety of configurations, the wrap 200 is shown having a generally rectangular configuration. The envelope of Figure 35 also provides another example of a membrane envelope having a pair of by-product ducts 252 and a pair of hydrogen ducts 250. As shown, the envelope 200 includes the feed plates, or separator, 238 as the outermost frames in the envelope. Generally, each of the plates 238 includes a frame 260 defining an open inner region 262. Each open inner region 262 is coupled laterally to the ducts 252. The ducts 250, however, are closed relative to the open region 262, which thus isolates the hydrogen rich stream 34. The membrane plates 242 are adjacent and internal to the plates 238. The membrane plates 242 each include as a central portion thereof a hydrogen selective membrane 46, which can be secured to an outer frame 240, which is shown for graphic illustration purposes. In the plates 242, all the ducts are closed relative to the membrane 46. Each membrane is adjacent to a corresponding one of the open regions 262, that is, adjacent to the mixed gas flow that reaches the envelope. This provides an opportunity for hydrogen gas to pass through the membrane, with gases that do not permeate, that is, gases that form the by-product stream 36, leaving the open region 262 through conduit 252. The plate screen 234 is positioned intermediate between the membranes 46 and / or the membrane plates 242, that is, inside or permeate side of each of the membranes 46. The screen plate 234 includes a screen structure 210 or other suitable support 54. The ducts 252 are closed relative to the central region of the display plate 234, thereby isolating the by-product stream 36 and the mixed gas stream 24 from the hydrogen-rich stream 34. The ducts 250 are open towards the inner region of the screen plate 234. The hydrogen gas, which has passed through the adjacent membranes 46, travels along and through the screen structure 210 to the conduits 250 and Finally, to an outlet port such as hydrogen-rich current 34.

As described, the device 10 may include a single membrane 46 within the cover 62, a plurality of membranes within the cover 62, one or more membrane wraps 200 within the cover 62 and / or other separation units 20 In Figure 36, a membrane wrap 200 similar to that shown in Figure 34 is shown positioned within the cover 62 to illustrate this point. It should be understood that the envelope 200 can also schematically represent a membrane module 220 containing a plurality of membrane envelopes, and / or a single membrane plate 242. An example of a suitable position for the structures is also shown for illustrative purposes. Guide 144. As described, structures 144 also represent an example of internal supports 196. Figure 36 also graphically illustrates an example of suitable positions for ports 64-68. To further illustrate suitable positions of the membrane plates and / or membrane envelopes within the devices 10 containing end plates according to the present invention, Figures 37 and 38 illustrate, respectively, in broken lines, a plate of membrane 242, a membrane wrap 200 and / or a membrane module 220 positioned within a device 10 that includes the end plates shown in Figures 13-14 and 21-25.

The cover 62 has been described as interconnecting the end plates to thereby define the internal compartment 18. It is within the scope of the invention that the cover can be formed from a plurality of interconnected plates 230. For example, a module of membrane 220 that includes one or more envelopes of membrane 200 can form a cover 62 because the perimeter regions of each of the plates can form a seal fluid tight, or at least substantially fluid tight between them. An example of such a construction is shown in Figure 39, in which a membrane module 220 is shown that includes three envelopes of the membrane 200. It should be understood that the amount of membrane envelopes may vary, from a single envelope or even a single membrane plate 242, up to a dozen or more. In Figure 39, end plates 60 are schematically depicted with generally rectangular configurations to illustrate that other configurations than circular configurations are within the scope of the invention. It should be understood that end plates 60 schematically represented may have any of the end plate configurations described, illustrated and / or incorporated in the present description.

In the above description, illustrative examples of suitable building materials for the components of the hydrogen purification devices according to the present invention have been described. It should be understood that the examples are not intended to represent an exclusive or closed list of illustrative materials and methods, and that it is within the scope of the invention that other materials may be used. For example, in many of the examples above, features or properties are presented that are convenient to provide guidance for selecting additional materials. This guide is also intended as an illustrative aid, rather than listing the essential requirements for all modalities.

As described, in the embodiments of the device 10 which includes a separation unit that includes hydrogen permeable membranes 46 and / or hydrogen selective, suitable materials for membranes 46 include palladium and palladium alloys. As also described, the membranes may be supported by frames and / or supports, such as the frames described above 240, the supports 54 and the screen structure 210. In addition, the devices 10 often operate with selected operating parameters that include high temperatures and pressures. In such an application, the devices typically begin in a state of initial onset or operation, in which the devices are typically at room temperature and pressure, such as atmospheric pressure and a temperature of approximately 25 ° C. From this state, the device is heated (such as with the heating unit 42) and pressurized (through any suitable mechanism) to the selected operating parameters, such as temperatures of 200 ° C or more, and pressures of selected operation, such as the pressure of 344.7 kPa (50 psi) or more.

When the devices 10 become hot, the components of the devices will expand. The degree to which the components are expanded or expanded is largely defined by the coefficient of thermal expansion (CTE) of the materials from which the components are formed. Consequently, these differences in CTEs will tend to cause the components to expand at different speeds, thereby exerting additional tension or compression on some components and / or reducing tension or compression on others.

For example, consider a selective hydrogen membrane 46 formed from an alloy of 60% by weight of palladium and 40% by weight of copper (Pd-40Cu). Such a membrane has a coefficient of thermal expansion of 14.9 | jm / m) / ° C. Also, consider that the membrane is secured to a structural frame 230 or other fastener, or retained against a support 54 formed from a material having a CTE different from that of Pd-40Cu or other material from which the membrane 46 is formed When a device 10 in which these components are operated is heated from an ambient or idle configuration, the components will expand at different speeds. Typically, the device 10 has a thermal cycle within a temperature range of at least 200 ° C, and often within a range of at least 250 ° C, 300 ° C or more. If the CTE of the membrane is less than the CTE of the adjacent structural component, then the membrane will tend to stretch as the components heat up.

In addition to this initial stretching, hydrogen purification devices should typically be considered to undergo thermal cycles when heated for use, then cooled or allowed to cool when not in use, then reheated, re-cooled, etc. In such an application, the stretched membrane may wrinkle as it compresses into its original configuration as the membrane and other structural component (s) cool.

On the other hand, if the CTE of the membrane is greater than the CTE of the adjacent structural component, then the membrane will tend to compress during heating of the device, and this compression can cause wrinkles in the membrane. During cooling, or when the components cool, the membrane returns to its original configuration.

As an illustrative example, consider the membrane plate 242 shown in Figure 34. If the CTE of the membrane 46 is larger than the CTE of the frame member 230, which typically has a different composition than the membrane 46, then the membrane It will tend to expand faster when heated than the frame. Consequently, compression forces will be imparted to the membrane from the frame 230, and these forces can produce wrinkles in the membrane. On the contrary, if the CTE of the membrane 46 is smaller than the CTE of the frame 230, then the frame will expand faster when heated than the membrane 46. As this occurs, expansion forces will be imparted to the membrane, since the expansion of the frame essentially tries to stretch the membrane. While neither of these situations is convenient, compared to an embodiment in which the frame and the membrane have the same or essentially the same CTE, the first scenario may be the most convenient of the two in some modalities because it may be less likely to produce wrinkles in the membrane.

The wrinkling of the membrane 46 can cause holes and cracks in the membrane, especially along the wrinkles where the membrane is fatigued. In regions where two or more wrinkles intersect, the likelihood of holes and / or cracks forming increases because that portion of the membrane has wrinkled in at least two different directions. It should be understood that holes and cracks decrease the selectivity of the membrane for hydrogen gas because the holes and / or cracks are not selective for hydrogen gas and, instead, allow any of the components of the flow stream. mixed gas pass to them. During repeated thermal cycles of the membrane, these points or regions of failure will tend to increase in size, which will further decrease the purity of the hydrogen-rich or permeate stream. It should also be understood that these wrinkles can be caused by forces imparted to the membrane from portions of the device 10 that come into contact with the membrane directly, and which can therefore be referred to as portions or structure in contact with the membrane, or by other portions of the device that does not come into contact with the membrane but that when expanding and / or cooling impart forces that are transmitted to the membrane. Examples of structure in contact with the membrane include frames or other fasteners 52 and brackets 54 on which the membrane is mounted or with which the membrane 46 is in contact even if the membrane is not really secured or otherwise mounted in the same. Examples of portions of device 10 that can, at least in some embodiments, impart wrinkle inducing forces to membrane 46 include enclosure 12, and portions thereof such as one or more end plates 60 and / or cover 62. Other examples include seals and spacers between the end plates and the frames or other fasteners for the membrane, and in the embodiments of the device 10 that include a plurality of membranes, between adjacent frames or other supports or fasteners for the membranes.

One approach to protect against membrane failure due to differences in CTE between membranes and adjacent structural components is to place deformable joints between the membrane and any component of the device 10 that contacts the membrane and has sufficient rigidity or structure. to impart compression or tensile forces to the membrane that can wrinkle the membrane. For example, in Figure 33, the membrane 46 is shown sandwiched between the feed plate 238 and the permeate joint 236, both of which can be formed of a deformable material. In such an embodiment and with such construction, the deformable joints dampen, or absorb, at least a significant portion of the compression or tensile forces that would otherwise be exerted on the membrane 46.

In the modalities where either or both of these frames are not formed from a deformable material (i.e., an elastic material that can be compressed or expanded as the forces are imparted thereto and returns to its original configuration upon elimination of those forces), when the membrane 46 is mounted on a plate 242 having a thickness and / or composition that can exert the tensile or wrinkle compression forces described above in the membrane 46, or when the support 54 is attached (or secured under the selected operating pressure) to the membrane 46, a different approach can be used additionally or alternatively. More specifically, the life of the membranes can be increased by forming components of the device 10 that would otherwise impart wrinkling forces, either tensile or compressive, to the membrane 46 from materials having a CTE that is equal or similar to that of the material or materials from which the membrane 46 is formed.

For example, Type 316 stainless steel has a CTE of 16.0. Consequently, Type 316 stainless steel has a CTE that is approximately 8% higher than that of Pd-40Cu. It may be convenient to have a CTE that is the same as the CTE of the material from which the membrane 46 is formed, or a material that has a CTE that is within a selected range of the CTE of the material from which the membrane is selected 46, such as within ± 0.5%, 1%, 2% or 5%. In other words, in at least some embodiments, it may be convenient to form the portions in contact with the membrane or other elements of the device from a material or materials having a CTE that is within ± 1.2, 1.0, 5, 0.2, 0.1 or less than 0.1 jm / m / ° C of the Te from which membrane 46 is formed at least substantially. Materials having one of the above compositions and / or CTE in relation to the CTE of the membrane 46 may be referred to herein as one of the CTE selected within the context of this description.

In the following table, illustrative alloys and their corresponding CTE and compositions are presented. It should be understood that the materials listed in the following table are provided for illustrative purposes.

Table 1

From the above information, it can be seen that alloys such as Type 330 and Incoloy 800 stainless steel have CTE that are within approximately 3% of the Pd40Cu CTE, and Monel 400 and Type 310S stainless steels have CTE that deviate from CTE of Pd40Cu in less than 7%.

To illustrate that the selection of materials may vary with the CTE of the particular membrane being used, consider a material for membrane 46 that has a thermal expansion coefficient of 13.8 jm / m / ° C. In the table above, it can be seen that the Monel and Inconel 600 alloys have CTE that deviate, or differ from the membrane CTE by 0.1 | jm / m / ° C. As another example, consider a membrane that has a CTE of 13.4 jm / m / ° C. Hastelloy X has a CTE that corresponds to that of the membrane, and that the Monel and Inconel 601 alloys have CTE that are within approximately 1% of the membrane CTE. From the illustrative example of the materials listed in the table, all alloys other than Hastelloy X, Incoloy 800 and Type 300 series of stainless steel alloys have CTEs that are within 2% of the membrane CTE and all alloys except Type 304, 316 and 310S stainless steel alloys have CTE that are within 5% of the membrane CTE.

Examples of components of device 10 that can be formed from a material having a selected CTE relative to membrane 46, such as a CTE corresponding to or within one of the selected ranges of the CTE of membrane 46, include one or more of the following: support 54, screen members 212, thin or outer screen or expanded metal member 216, inner screen member 214, membrane frame 240, permeate frame 232, permeate plate 234, feed plate 238. By the foregoing, it should be understood that one of the above components may be formed from such material, more than one of the above components may be formed from such material, but that it is not required that any of the above components be formed from of such material. Similarly, the membranes 46 may be formed from materials other than Pd-40Cu, and as such, the selected CTEs will vary depending on the particular composition of the membranes 46.

By way of further illustration, a device 10 can be formed with a membrane module 220 that includes one or more membrane envelopes 200 with a support that includes a screen structure that is completely formed of a material having one of the selected CTEs. . As another example, only the outer screen members, or in contact with the membrane (such as members 216) can be formed from a material having one of the selected CTEs, with the inner member or members that are formed from of a material that does not have one of the selected CTEs. As another illustrative example, the inner screen member 214 may be formed from a material that has one of the selected CTEs, with the members in contact with the membrane that are formed from a material that does not have one of the selected CTEs. , etc.

In some embodiments, it may be sufficient that only portions of the support that have sufficient rigidity to cause wrinkles in the membranes during the thermal cycle and other intended uses of the purification device are formed from a material having one of the selected CTEs . As an illustrative example, consider the screen structure 210, shown in Figure 32. In the illustrative mode, the screen structure is adapted to be positioned between a pair of membranes 46, and the screen structure includes a pair of members of external screen or in contact with the membrane 216, and an internal screen member 214 that is not in contact with the membranes. Typically, but not exclusively, the external screen members are formed by a material that is less rigid and often thinner than the internal screen member, which tends to have a more rigid and often thicker construction. In such an embodiment, the internal screen member may be formed from a material having one of the selected CTEs, such as an alloy that includes nickel and copper, such as Monel, with the screen members external that are formed of conventional stainless steel, such as Type 304 or Type 316 stainless steel. Such a screen structure can also be described as having a screen member in contact with the membrane with a CTE that differs from the CTE of the membrane 46 plus than the CTE of the material from which the internal screen member is formed. However, as described, it is also within the scope of the invention that all screen members can be formed from an alloy that includes nickel and copper, such as Monel, or other material having one of the selected CTEs.

This construction can also be applied to supports that include more than one member or screen layer, but only support one membrane. For example, and with reference to Figure 2, the support may include a layer or screen member in contact with the membrane 214 ', which may have a construction like that of a screen member 214. The layer 214' is coupled and It extends through at least a substantial portion of the membrane face, but typically does not provide sufficient support to the membrane when the purification device is pressurized and in use. The support may further include a second layer or second screen member 216 ', which may have a construction similar to screen member 216 and which generally extends parallel to the first layer but on the opposite side of the first layer of the membrane. This second layer is more rigid than the first layer, so that it provides a composite screen structure that has sufficient strength, or stiffness, to support the membrane when in use. When such a construction is used, it can (but is not required) be implemented with the second layer, or the screen member will be formed from a nickel-copper alloy, such as Monel, or other material having a selected CTE, and with the layer in contact with the membrane, or screen member, which is formed from a material having a CTE that differs from the membrane CTE in an amount greater than the material from which the second layer is formed. In addition, the layer in contact with the membrane can be described as being formed from a material that does not include a nickel-copper alloy.

Another example of illustrative configurations, a device 10 may have a single membrane 46 supported between the end plates 60 of the enclosure by one or more fasteners 52 and / or one or more supports 54. The fasteners and / or the supports can be formed from of a material that has one of the selected CTEs. Similarly, at least a portion of the enclosure 12, such as one or both end plates 60 or cover 62, can be formed from a material having one of the selected CTEs.

In the modalities of the device 10 in which there are components of the device that do not come into direct contact with the membrane 46, these components can still be formed from a material having one of the selected CTEs. For example, a portion or all of the enclosure 12, such as one or both end plates 60 or cover 62, may be formed from a material, which includes one of the alloys listed in Table 1, which have one of the CTE selected with respect to the CTE of the material from which membrane 46 is formed, even if these portions do not come directly in contact with membrane 46.

A hydrogen purification device 10 can be coupled to, or be in continuous communication with, any source of impure hydrogen gas. Examples of these sources include gas storage devices, such as hydride beds and pressurized tanks. Another source is an apparatus that produces as a byproduct, exhaust or waste stream a gas stream from which hydrogen gas can be recovered. Yet another source is a fuel processor, which, as used herein, refers to any device that is adapted to produce a mixed gas stream containing hydrogen gas of at least one feed stream containing a raw material. . Typically, the hydrogen gas will form a majority or at least a substantial portion of the mixed gas stream produced by a fuel processor.

A fuel processor can produce a mixed gas stream 24 through a variety of mechanisms. Examples of suitable mechanisms include steam reforming and autothermal reforming, in which reforming catalysts are used to produce hydrogen gas from a feed stream containing a raw material containing carbon and water. Other suitable mechanisms for producing hydrogen gas include pyrolysis and catalytic partial oxidation of a carbon-containing raw material, in which case the feed stream does not contain water. Yet another suitable mechanism for producing hydrogen gas is electrolysis, in which case the raw material can be water. Examples of suitable carbon-containing raw materials include at least one hydrocarbon or alcohol. Examples of suitable hydrocarbons include methane, propane, natural gas, diesel, kerosene, gasoline and the like. Examples of suitable alcohols include methanol, ethanol, and polyols, such as ethylene glycol and propylene glycol.

A hydrogen purification device 10 adapted to receive the mixed gas stream 24 from a fuel processor is schematically shown in Figure 40. As shown, the fuel processor is generally indicated at 300, and the combination of a fuel processor and a hydrogen purification device can be referred to as a fuel processing system 302. A unit is also shown in broken lines at 42 heating, which as described provides heat to device 10 and can take a variety of forms. The fuel processor 300 can take any of the forms described above. To graphically illustrate that a hydrogen purification device can also receive a mixed gas stream 24 from sources other than the fuel processor 300, a gas storage device 306 and an apparatus producing a mixed gas stream 24 are schematically illustrated. as a stream of waste or by-products in the course of producing a different product stream 308 is shown in 310. It must It is understood that the schematic representation of the fuel processor 300 is intended to include any associated heating unit, raw material supply systems, air supply systems, power supply sources or supplies, etc.

Fuel processors are often operated at high temperatures and / or pressures. As a result, it may be convenient to at least partially integrate the hydrogen purification device 10 with the fuel processor 300, as opposed to having the device 10 and the fuel processor 300 connected by external fluid transport conduits. An example of such a configuration is shown in Figure 42, in which the fuel processor includes a cover or housing 312, whose device 10 forms a portion of and / or extends at least partially inside. In such a configuration, the fuel processor 300 can be described as including the device 10. The integration of the fuel processor or other mixed gas stream source 24 with the hydrogen purification device 10 allows the devices to move more easily as a unit. It also allows the components of the fuel processor, which includes the device 10, to be heated by a common heating unit and / or at least some, if not all, the heating requirements of the device 10 must be satisfied with the heat generated by the 300 processor

As described, the fuel processor 300 is any suitable device that produces a mixed gas stream containing hydrogen gas, and preferably a mixed gas stream containing a majority of hydrogen gas. For illustration purposes, the following description will describe the fuel processor 300 that is adapted to receive a feed stream 316 containing a raw material containing carbon 318 and water 320, as shown in Figure 42. However, the processor Fuel 300 may take other forms, as described above, and that feed stream 316 may have other compositions, such as containing only a raw material containing carbon or only water.

The supply current 316 can be delivered to the fuel processor 300 through any suitable mechanism. A single supply current 316 is shown in Figure 42, but it should be understood that more than one current 316 can be used and that these currents may contain the same or different components. When the carbon-containing raw material 318 is miscible with water, the raw material is typically delivered with the water component of the feed stream 316, as shown in Figure 42. When the carbon-containing feed material is not miscible or only slightly miscible with water, these components are typically delivered to the fuel processor 300 in separate streams, as shown in broken lines in Figure 42. In Figure 42, the feed stream 316 is shown that is delivered to the fuel processor 300 by a power supply system 317. The supply system 317 includes any suitable mechanism, device or combination thereof that delivers the feed current to the fuel processor 300. For example, the supply system it may include one or more pumps that deliver the components of current 316 from a supply. Additionally or alternatively, system 317 may include a set of valves adapted to regulate the flow of the components from a pressurized supply. Supplies may be located outside the fuel cell system, or they may be contained within or adjacent to the system.

As generally indicated in 312 in Figure 42, the fuel processor 300 includes a hydrogen producing region in which the mixed gas stream 24 is produced from the feed stream 316. As described, a variety can be used. of different processes in the hydrogen producing region. An example of such a process is steam reforming, in which region 312 includes a steam reforming catalyst 334. Alternatively, region 312 can produce stream 24 by autothermal reforming, in which case region 312 includes a catalyst of autothermal reforming. In the context of a steam or autothermal reformer, the mixed gas stream 24 can also be referred to as the reforming stream. Preferably, the fuel processor is adapted to produce substantially pure hydrogen gas, and even more preferably, the fuel processor is adapted to produce pure hydrogen gas. For the purposes of the present invention, the substantially pure hydrogen gas has a purity greater than 90%, preferably a purity greater than 95%, more preferably a purity greater than 99%, and even more preferably a purity greater than 99, 5 %. Examples of suitable fuel processors are described in U.S. Patent No. 6,221,117 pending US patent application with serial number 09 / 802,361, which was filed on March 8, 2001, and is entitled "Fuel Processor and Systems and Devices Containing the Same" and the pending United States patent application with Serial number 09 / 812,499, which was filed on March 19, 2001, and is titled "Hydrogen-Selective Metal Membrane Modules and Method of Forming the Same,".

The fuel processor 300 may, but not necessarily, also include a polishing region 348, as shown in broken lines in Figure 42. The polishing region 348 receives the hydrogen-rich stream 34 from the device 10 and further purifies the current by reducing the concentration or by eliminating the compositions selected therein. In Figure 42, the resulting stream is indicated in 314 and can be referred to as a product hydrogen stream or a purified hydrogen stream. When the fuel processor 300 does not include the polishing region 348, the hydrogen rich stream 34 forms the hydrogen stream of the product 314. For example, when stream 34 is designed for use in a stack of fuel cells, the Compositions that can damage the fuel cell stack, such as carbon monoxide and carbon dioxide, can be removed from the hydrogen-rich stream, if necessary. The concentration of carbon monoxide should be less than 10 ppm (parts per million) to prevent the control system from isolating the fuel cell stack. Preferably The system limits the concentration of carbon monoxide to less than 5 ppm, and even more preferably, to less than 1 ppm. The concentration of carbon dioxide may be greater than that of carbon monoxide. For example, concentrations of less than 25% carbon dioxide may be acceptable. Preferably, the concentration is less than 10%, even more preferably, less than 1%. Especially preferred concentrations are less than 50 ppm. It should be understood that the minimum acceptable concentrations presented in the present description are illustrative examples, and that other concentrations than those presented in the present description can be used and are within the scope of the present invention. For example, particular users or manufacturers may require minimum or maximum concentration levels or ranges that are different from those identified in this description.

Region 348 includes any structure suitable for eliminating or reducing the concentration of the selected compositions in stream 34. For example, when the product stream is intended for use in a PEM fuel cell stack or other device that will be damaged if the stream contains more than the determined concentrations of carbon monoxide or carbon dioxide, it may be convenient to include at least one bed of methanization catalyst 350. Bed 350 converts carbon monoxide and carbon dioxide into methane and water, which They will not damage a PEM fuel cell stack. Polishing region 348 may also include another hydrogen producing region 352, such as another bed of reforming catalyst, to convert any unreacted raw material into hydrogen gas. In such an embodiment, it is convenient that the second reforming catalyst bed is upstream of the methanization catalyst bed so as not to reintroduce carbon dioxide or carbon monoxide downstream of the methanization catalyst bed.

Steam reformers typically operate at temperatures in the range of 200 ° C and 700 ° C, and at pressures in the range of 344.7 kPa (50 psi) and 6894.8 kPa (1000 psi), although temperatures outside of this Range depends on the particular type and configuration of the fuel processor used. Any suitable heating mechanism or device can be used to provide this heat, such as a heater, a burner, a combustion catalyst or the like. The heating unit may be external to the fuel processor or it may form a combustion chamber that is part of the fuel processor. The fuel for the heating unit may be provided by the fuel processing or the fuel cell system, by an external source, or both.

In Figure 42, the fuel processor 300 is shown which includes a cover 312 in which the components described above are contained. The cover 312, which can also be referred to as a housing, allows the components of the fuel processor to move as a unit. It also protects the components of the fuel processor against damage by providing a protective enclosure and reduces the heating demand of the fuel processor because the components of the fuel processor can be heated as a unit. The cover 312 may, but not necessarily, include insulating material 333, such as a solid insulating material, insulating layer material or a cavity filled with air. The fuel processor can be formed without a housing or cover. When the fuel processor 300 includes insulating material 333, the insulating material may be internal to the cover, external to the cover or both. When the insulating material is external to a cover containing the reforming, separation and / or polishing regions described above, the fuel processor may further include an outer coating or jacket external to the insulation.

One or more of the components of the fuel processor 300 may extend beyond the cover or be located at least outside the cover 312. For example, the device 10 may extend at least partially beyond the cover 312, as indicated in Figure 41. As another example, and as schematically illustrated in Figure 42, the polishing region 348 may be an outer shell 312 and / or a portion of the hydrogen producing region 312 (such as the portions of one or more beds of reforming catalysts) can extend beyond the deck.

As indicated above, the fuel processor 300 can be adapted to deliver the hydrogen rich stream 34 or the hydrogen stream of the product 314 to at least one fuel cell stack, which produces an electric current therefrom. In such a configuration, the fuel processor and the fuel cell stack can be referred to as a fuel cell system. An example of such a system is schematically illustrated in Figure 43, in which a fuel cell stack is generally indicated at 322. The fuel cell stack is adapted to produce an electric current from the portion of the hydrogen current of the product 314 delivered to it. In the illustrated embodiment, a single fuel processor 300 and a single fuel cell stack 322 are shown and described, however, it should be understood that more than one or any of these two components can be used. It should also be understood that these components have been schematically illustrated and that the fuel cell system may include additional components that are not specifically illustrated in the figures, such as feed pumps, air supply systems, heat exchangers, heating units and the like

The fuel cell stack 322 contains at least one, and typically multiple, fuel cells 324 that are adapted to produce an electric current from the portion of the hydrogen stream of the product 314 delivered thereto. This electric current can be used to meet the energy demands, or applied load, of an associated device that consumes energy 325. Illustrative examples of devices 325 include, but should not be limited to, a motor vehicle, a recreational vehicle, a boat , tools, lights or lighting sets, appliances (such as a home or other device), home, signaling or communication equipment, etc. It should be understood that the device 325 is schematically illustrated in Figure 43 and is intended to represent one or more devices or a collection of devices that are adapted to extract electric current from the fuel cell system. A fuel cell stack typically includes multiple fuel cells joined between common end plates 323, which contain fluid supply / disposal conduits (not shown). Examples of suitable fuel cells include proton exchange membrane (PEM) fuel cells and alkaline fuel cells. The fuel cell stack 322 can receive all of the hydrogen stream of the product 314. A part or all of the stream 314 can be supplied additionally or alternatively, through a suitable conduit, for use in another process of consumption of hydrogen, burned for fuel or heat, or stored for later use.

Industrial applicability

The hydrogen purification devices, components and fuel processing systems described are applicable to fuel processing and other industries in which hydrogen gas is produced and / or used.

Although the invention has been described in its preferred form, the specific embodiments thereof as described and illustrated in the present description should not be considered in a limiting sense, since numerous variations are possible. Similarly, when the claims enumerate "a" or "a first" element or its equivalent, it should be understood that such claims include the incorporation of one or more such elements, which do not require or exclude two or more such elements.

Claims (8)

i. The use, to prevent the formation of wrinkles of at least one selective hydrogen membrane (46, 202) in a hydrogen purification device (10) comprising an enclosure (12) that defines an internal compartment (18) and contains a separation unit (20), which divides the internal compartment into a mixed gas region (30) and a permeate region (32), the hydrogen purification device that is adapted to receive a mixed gas stream (24) that it contains hydrogen gas (26) and other gases (28) and to produce a stream (34), which contains pure or at least substantially pure hydrogen gas, wherein the substantially pure hydrogen gas has a purity greater than 90%, and a stream by-product (36), which contains at least a substantial portion of the other gases, therefrom, of means for supporting said at least one membrane (46), from which at least one portion is selected to have a Coefficient of thermal expansion that is within 10% of the thermal expansion coefficient of the at least one membrane (46, 202). 2. The use according to claim 1, wherein said at least a portion is formed from an alloy that includes nickel and copper. 3. The use according to claim 1 or claim 2, wherein the thermal expansion coefficient of said at least one portion is within 5% of that of the at least one membrane (46, 202), optionally within 2 % thereof, and optionally also within 1% thereof. 4. The use according to any of claims 1 to 3, wherein the coefficient of thermal expansion of said at least one portion is less than that of the at least one membrane. 5. The use according to any of claims 1 to 4, wherein the support means comprise at least one of a fastener (52) adapted to position the membrane within the enclosure, or a support (54) extending to through at least a substantial portion of the membrane (46, 202). The use according to any one of claims 1 to 5, wherein said at least one membrane (46, 202) is composed of palladium or a palladium alloy, and optionally an alloy containing palladium and 40% by weight of copper. 7. The use according to any of claims 1 to 6, wherein the coefficient of thermal expansion of said at least one portion deviates from that of at least one membrane at no more than 1 pm / m / ° C, and optionally at no more than 0.2 pm / m / ° C, and optionally no more than 0.1 pm / m / ° C. 8. The use according to any of claims 1 to 7, wherein the at least a portion of the support means includes a structure in contact with the membrane (52, 54, 210, 230, 240).