Device for coupling and sealing metal hydrogen separation membrane to metal connector

Abstract

The present invention provides a coupling and sealing device for coupling and sealing together a hydrogen separation membrane with a metal connector, the coupling and sealing device comprising: a metal hydrogen separation membrane mounted on or against a connector structure of the connector about a longitudinal axis, a connector formed of a metal different from the hydrogen separation membrane, the hydrogen separation membrane having an outer diameter (D) about the longitudinal axis, the hydrogen separation membrane and the connector structure being in contact at a connection interface in which an end face of the hydrogen separation membrane is close to, substantially adjacent to, or overlapping an adjacent face of the connector structure; a connection portion connecting the hydrogen separation membrane and the connector structure around the connection interface; and a restriction collar configured to extend at least from the connection interface and axially extend over the hydrogen separation membrane relative to the longitudinal axis, the restriction collar including: an expansion section configured to expand the hydrogen separation membrane; the expansion section is configured to extend axially above the hydrogen separation membrane relative to the longitudinal axis from a confined end to a post-expansion diameter, the confined end being configured to extend about the hydrogen separation membrane relative to the longitudinal axis at or near the connection interface, the present invention relates to a hydrogen separation membrane comprising an expanded section extending from a confined end and having an inner surface defining a confined diameter (C), the inner surface being configured to extend around an outer surface of the hydrogen separation membrane, where the expanded section comprises a transition section extending from the confined end and comprising a curved surface having a transition radius of at least 0.1 D; and wherein the expansion section comprises an angled or curved section in which the diameter of the limiting collar expands from the limiting diameter C to a post-expansion diameter comprising at least 1.01 D.

Description

[0001] Priority Cross Reference

[0002] This application claims priority to Australian Provisional Patent Application No. 2022901905 filed on July 7, 2022, the contents of which should be understood to be incorporated into this specification by this reference. Technical Field

[0003] The present invention generally relates to an apparatus for coupling and sealing a metal hydrogen separation membrane to a metal connector. The present invention is particularly suitable for coupling and sealing a vanadium-based tubular membrane to a stainless steel gas fitting. However, it should be understood that the present invention can be used to couple and seal a hydrogen separation membrane of any metal type to any type of metal fitting or body. Background Art

[0004] The following discussion of the background of the invention is intended to assist understanding of the invention. However, it should be appreciated that the discussion is not an acknowledgement or admission that any of the material referred to was published, known or part of the common general knowledge as at the priority date of the application.

[0005] Hydrogen (H2) is not abundant in nature. In industrial practice, it is produced by converting hydrocarbon fuels such as coal, oil or natural gas, by decomposing ammonia (NH 3 ) or by electrochemical water splitting. Each of these production routes produces H 2 and unreacted feed gas (e.g. CH 4 , H 2 O、NH 3 ) and such as CO 2 , CO and N 2 For many applications, it is necessary to 2 Separated from the mixed gas stream.

[0006] Membrane-based separation technology can be used to separate H from mixed gas streams. 2 In a broad sense, a membrane is a nearly two-dimensional structure that is selectively permeable to one substance. In the context of gas separation, a membrane allows one substance to selectively permeate (H 2 ), while preventing other substances (such as CO, CO 2 , H 2 O、N 2 etc.). Hydrogen-selective membranes can be created from inorganic, metallic, or ceramic materials, each with characteristic hydrogen throughput, operating temperature, and selectivity.

[0007] Palladium is the most famous alloy membrane material, which is able to permeate hydrogen between 300 and 600 °C while being resistant to gases such as CO and H 2However, the high cost of palladium (AUD$100-130 / g Pd (May 2022)) has driven research efforts towards minimising Pd consumption, most notably through alloying with cheaper metals and minimising thickness by depositing very thin (<5 microns) layers on support structures with very fine pores.

[0008] Many other metals also exhibit very high hydrogen permeabilities, most notably vanadium, titanium, tantalum, niobium, and zirconium. At 400°C, these metals have hydrogen permeabilities that are approximately two orders of magnitude higher than palladium, and the raw material price is significantly lower. Of these metals, vanadium has the widest alloying range, meaning it has the widest scope for changing alloy properties to meet the needs of vanadium-based membranes. An example of a vanadium-based membrane is taught in Applicant's U.S. Patent Publication No. US20150368762A1.

[0009] The vanadium-based membrane is usually connected to another tube or pipe and sealed to extract H 2 Provides flow path and prevents non-H 2 The gaseous material passes through the membrane. The seal / connection of the membrane to the connector is critical to the successful application of V-based membrane technology to separate high-purity hydrogen from a mixed gas feed containing hydrogen. In this regard, high-purity hydrogen suitable for fuel cell electric vehicles (FCEVs) requires a purity of >99.97% as specified in ISO 14687, as well as other high-purity hydrogen such as NH 3 and N 2 Seal failure results in contamination of the hydrogen product, meaning that the membrane is no longer “suitable” for producing high-purity hydrogen.

[0010] One connection and sealing technology for tubular vanadium-based membranes is to utilize a brazing or welding connection between the vanadium-based membrane and a metal fitting (e.g., an end cap or a connection fitting). An example of a device for coupling a vanadium-based membrane to a metal fitting is taught in International Patent Publication No. WO2019000026A1, which teaches a brazing technology for coupling and sealing a vanadium-based membrane to a metal connector, wherein a filler or brazing metal is used to form a bridging section of filler metal between the vanadium-based membrane and the connector over the connection interface.

[0011] An example of a welding device for joining a vanadium-based membrane to a metal fitting is taught in VN Alimov, IV Bobylev, AOBusnyuk, SNKolgatin, SR Kuzenov, E. Yu. Peredistov, AILivshits. International Journal of Hydrogen Energy, Volume 43, Issue 29, 19 July 2018, Pages 13318-13327. The device shown appears to use a small bridging collar that is placed over the vanadium-based membrane and the adjacent metal fitting, which is then sealed (e.g., arc welded) to join the vanadium-based membrane to the adjacent metal fitting.

[0012] However, vanadium-based hydrogen separation membrane tubes can have a linear (dimensional) expansion of up to about +5% and a volume expansion of up to about +15% when hydrided at conventional operating temperatures and pressures, compared to ambient conditions without hydrogen. Other Group 5 metals also have similar hydriding expansion properties. None of the above-described coupling arrangements adequately account for the linear and volume expansion of these types of metal hydrogen separation membranes when exposed to hydrogen and the strains and stresses that may affect the integrity of the seal and coupling around the sealed joint. In each case, the brazed or welded joint is not protected from the volume expansion of the metal hydrogen separation membrane adjacent to the joint.

[0013] It would therefore be desirable to provide an improved and / or alternative method of connecting and sealing a vanadium or vanadium alloy based tubular membrane to an adjacent metal tube or pipe. Summary of the invention

[0014] The present invention provides a coupling and sealing apparatus including a confinement collar for coupling and sealing a metal hydrogen separation membrane to a metal fitting (eg, a stainless steel fitting), an associated method, and a hydrogen separation membrane confinement collar.

[0015] A first aspect of the present invention provides a coupling and sealing device for coupling and sealing a hydrogen separation membrane to a metal connector, the coupling and sealing device comprising:

[0016] a metal hydrogen separation membrane mounted on or against a connector structure of the connector about a longitudinal axis, the connector being formed of a metal different from the hydrogen separation membrane, the hydrogen separation membrane having an outer diameter (D) about the longitudinal axis, the hydrogen separation membrane and the connector structure being in contact at a connection interface in which an end face of the hydrogen separation membrane is proximate to, substantially abuts against, or overlaps an adjacent face of the connector structure;

[0017] a connecting portion connecting the hydrogen separation membrane and the connector structure around the connection interface; and

[0018] a confinement collar configured to extend from at least the connection interface and to extend axially above the hydrogen separation membrane relative to the longitudinal axis, the confinement collar comprising:

[0019] an expansion section configured to extend axially from a restricted end to an expanded diameter above the hydrogen separation membrane relative to the longitudinal axis, the restricted end configured to extend around the hydrogen separation membrane relative to the longitudinal axis at or near the connection interface and having an inner surface defining a restricted diameter (C) configured to extend around an outer surface of the hydrogen separation membrane,

[0020] wherein the expansion section comprises a transition section extending from the limiting end, the transition section comprising a curved surface having a transition radius of at least 0.1D,

[0021] And wherein the expansion section comprises an angled or curved section in which the diameter of the restraining collar expands from the restraining diameter to an expanded diameter comprising at least 1.01D.

[0022] The inventors have found that the connection between the metal hydrogen separation membrane and the connector itself may be prone to failure (causing leakage) and may not be able to adapt to changes in membrane hydrogenation as expected. The coupling and sealing device of the first aspect of the present invention is designed to constrain the volume expansion of the metal hydrogen separation (hydrogen selective) tubular membrane at or near the connection joint between the hydrogen separation membrane and the connector when exposed to hydrogen. The limiting collar of this coupling and sealing device has an expansion section that transitions from a limiting diameter at the limiting end of the expansion section to a larger expanded diameter, and the expansion section allows the hydrogenated hydrogen separation membrane to expand (preferably gradually or stepwise) to its naturally hydrogenated expanded diameter as the hydrogen separation membrane extends away from the connection between the hydrogen separation membrane and the connector along the longitudinal axis within the limiting collar.

[0023] The limiting end of the limiting collar may include a limiting section configured to move the expansion zone of the hydrogen separation membrane away from the connection interface / joint, thereby reducing strain on the weld joint. In these embodiments, the limiting section is configured to extend axially from the connection end to the expansion section above the hydrogen separation membrane relative to the longitudinal axis, and the limiting section has an inner surface extending around the longitudinal axis with a limiting diameter. The transition section here extends from a transition area, location or point where the limiting section intersects the expansion section.

[0024] It should be understood that the transition section includes a curved surface that forms a transition surface from the restricted end / restricted section to the expansion section of the collar. The curved surface has a curve that follows a radial curve of at least 0.1D. It should be understood that the curve typically includes only a small segment or portion of the radial curve, wherein the curve connects the restricted end / restricted section and the end of the expansion section and forms a transition surface between the restricted end / restricted section and the expansion section.

[0025] When hydrogen is introduced into the hydrogen separation membrane, the hydrogenated hydrogen separation membrane will expand within the confinement collar, and within the confinement section, the expansion will be constrained by the limits of the inner surface of the confinement collar. The collar of this first aspect of the invention is configured to increase the size of the region where confinement-induced stress occurs along the hydrogen separation membrane. Rather than having stress concentration at the interface or near the connection interface, the stress load moves away from the connection interface and disperses along the confinement section. This reduces the stress load on the connection interface, dispersing the amplitude of the stress across the confinement collar rather than at the connection interface point. Therefore, the collar allows the seal between the hydrogen separation membrane and the connector to remain intact during the expansion and contraction changes experienced during the membrane hydrogenation changes.

[0026] It should be understood that the outer diameter D is the outer diameter of the hydrogen separation membrane when the hydrogen separation membrane is in an unhydrogenated state (ie, not in a hydrogenated expanded state). The outer diameter depends on the size of the membrane used for hydrogen separation, and therefore can have any suitable size. In an embodiment, the outer diameter (D) can be from 2 to 25 mm. In some embodiments, the outer diameter (D) of the hydrogen separation membrane is between 5 mm and 20 mm, preferably 7 to 15 mm, and more preferably from 8 to 12 mm. In some embodiments, the outer diameter (D) of the hydrogen separation membrane is between 8.5 mm and 10 mm, preferably 9 to 10 mm, and more preferably about 9.5 mm. In some embodiments, the outer diameter (D) can be from 25 to 1000 mm, preferably from 25 to 100 mm. In other embodiments, the outer diameter (D) can be from 100 to 1000 mm, preferably from 200 to 800 mm.

[0027] The limiting diameter C is preferably sized to be between 0.95D and 1.05D. In an embodiment, the limiting diameter includes 0.97D to 1.05D, preferably 0.99D to 1.05D, more preferably 1D to 1.05D. In some embodiments, the limiting diameter includes 0.98D to 1.05D, preferably 0.999D to 1.05D. In some embodiments, the limiting diameter includes 1D to 1.04D, preferably from 1D to 1.02D, more preferably from 1.005D to 1.01D. In some embodiments, the limiting diameter is sized to provide a tight fit (0.95D to 1D), which requires force to assemble the limiting end of the expansion section and (in applicable embodiments) the limiting section above the hydrogen separation membrane. In other embodiments, the limiting diameter is sized to have a diameter greater than the outer diameter of the hydrogen separation membrane to allow the limiting end of the expansion section and (if applicable) the limiting section to be assembled (preferably sliding fit) above the hydrogen separation membrane. In these embodiments, it should be understood that when the hydrogen separation membrane is in an unhydrogenated state, the inner surface of the restriction end and (in applicable embodiments) the restriction diameter of the restriction section are preferably spaced apart from the outer surface (having an outer diameter D) of the hydrogen separation membrane. When the hydrogen separation membrane is in a hydrogenated state, the inner surface of the restriction section will abut or engage the outer surface of the hydrogen separation surface. The restriction diameter is preferably configured so that the inner surface of the restriction section is spaced apart from the hydrogen separation membrane in an unhydrogenated state, so that the membrane can be assembled therein without interference. However, the gap is also preferably designed to be small enough so that the expansion of the hydrogen separation membrane within a set distance from the connection interface can be limited without causing the hydrogen separation membrane to expand significantly so that the connection is subjected to strain or other undesirable forces, which may otherwise affect the integrity of the seal created by the connection.

[0028] The inner surface of the restriction section is preferably substantially parallel and spaced apart from the outer surface of the hydrogen separation membrane. In an embodiment, the restriction diameter is greater than 1D. The spacing at least provides a small gap so that the hydrogen separation membrane and the connector can be assembled in the restriction collar. The restriction diameter generally has an upper limit on its ability to reduce (preferably substantially limit) the movement of the hydrogen separation membrane around the connection between the hydrogen separation membrane and the connector during the changes in the membrane hydrogenation changes that undergo expansion and contraction. In an embodiment, the restriction diameter includes greater than 1D to 1.05D, preferably greater than 1D to 1.04D, more preferably greater than 1D to 1.02D. In a specific embodiment, the restriction diameter includes 1.005D to 1.01D. In other embodiments, the restriction diameter is greater than 1D to 1D plus 0.05mm, preferably greater than 1D to 1D plus 0.04mm.

[0029] The expanded diameter D2 is selected to be larger than the outer diameter D of the metal hydrogen separation membrane. In this sense, the expanded diameter D2 is larger than the outer diameter D of the metal hydrogen separation membrane when the metal hydrogen separation membrane is in an unhydrogenated state. In an embodiment, the expanded diameter D2 is at least 1.01D, preferably at least 1.02D. In some embodiments, the expanded diameter D2 is selected to be larger than the maximum diameter (diameter D) of the hydrogen separation membrane after hydrogenation. MH ). Compared to the ambient conditions without hydrogen, the hydrogen separation hydrogen selective membrane tube (e.g., vanadium-based hydrogen separation membrane) can expand in volume by at least about +10%, more typically +13%, and in linear expansion in one direction / axis by up to 5% - e.g., diameter - when hydrogenated at normal operating temperature / pressure. Therefore, in an embodiment, the expanded diameter D2 is at least 1.05D to accommodate this linear expansion when the hydrogen separation membrane is hydrogenated. In an embodiment, the expanded diameter D2 is at least 1.07D, preferably at least 1.08D, and more preferably at least 1.1D. In some embodiments, the expanded diameter D2 is at least 1.12D, and preferably at least 1.2D.

[0030] It should be understood that the expanded diameter D2 will also be larger than the restricted diameter C of the restricted section of the restriction collar. In this sense, the expanded diameter D2 is larger in size than the restricted diameter C. In an embodiment, the expanded diameter D2 is at least 1.01C, preferably at least 1.02C. In an embodiment, the expanded diameter D2 is at least 1.05C to accommodate the linear expansion of the hydrogen separation membrane during hydrogenation (as described above). In an embodiment, the expanded diameter D2 is at least 1.07C, preferably at least 1.08C, and more preferably at least 1.1C. In some embodiments, the expanded diameter D2 is at least 1.12C, and preferably at least 1.2C.

[0031] The maximum diameter of the hydrogen separation membrane after hydrogenation (diameter D MH ) will also be larger than the limiting diameter C of the limiting section of the limiting collar. Similarly, the maximum diameter of the hydrogen separation membrane after hydrogenation (diameter D MH ) will also be larger than the outer diameter D of the metal hydrogen separation membrane when the metal hydrogen separation membrane is in an unhydrogenated state - this can be understood from the nature of the hydrogenation process.

[0032] It should be understood that the diameter of the hydrogen separation membrane after hydrogenation (diameter D H ) will vary across the coupling and sealing arrangements depending on the location of the hydrogen separation membrane within the confinement collar. For example, within the confinement section, the diameter D H will be constrained to the limiting diameter C, while in the expansion section, the diameter D H The diameter to which it is constrained will be followed until the maximum diameter of the hydrogen separation membrane after hydrogenation (diameter D MH ).

[0033] The expansion section may include a linear, curved or other shaped or contoured surface that generally expands from a restricted diameter to an expanded diameter. As described above, the function of the expansion section is to provide a transition from a restricted diameter at the restricted end of the expansion section to a larger expanded diameter, thereby allowing the hydrogenated hydrogen separation membrane to expand (preferably gradually or stepwise) to its naturally hydrogenated expanded diameter as the hydrogen separation membrane extends away from the connection between the hydrogen separation membrane and the connector along the longitudinal axis within the limiting collar. The shape may have an uneven or irregular shape or contour. However, it is preferred that the shape is generally regular and / or smooth, for example, the area / surface after the transition section includes a linear expansion angle or a smooth curve. In the case where the expansion section includes a curve, the curve may include a continuous curve of the curve containing the transition section. In some embodiments, the transition section follows a curve that is identical or similar to the entire surface of the expansion section, and may share a common radius. Here, the angled or curved sections of the expansion section after the transition section and the transition section have the same or similar curves and may share a common radius.

[0034] The change from the limiting diameter to the expanded diameter in the expansion section can have any suitable shape or configuration. In some embodiments, the expansion section includes an inclined or curved surface extending from the transition section to the expanded diameter. In an embodiment, the expansion section includes a tapered surface. In an embodiment, the expansion section includes a contoured surface. For example, the diameter of the limiting collar can be configured to expand from the limiting diameter to the expanded diameter in the expansion section at an average expansion angle relative to the longitudinal axis, the average expansion angle including a non-zero angle of less than 17.5 degrees (i.e., an angle greater than zero to 17.5 degrees), preferably from 0.5 to 6 degrees, and more preferably from 3 to 5 degrees. In some embodiments, the diameter of the limiting collar can be configured to expand from the limiting diameter to the expanded diameter in the expansion section at an average expansion angle relative to the longitudinal axis, the average expansion angle including a non-zero angle of less than 15 degrees, preferably a non-zero angle of less than 10 degrees (i.e., an angle greater than zero to 10 degrees), preferably an angle from 1 to 10 degrees, more preferably from 3 to 6 degrees, and more preferably from 4 to 5 degrees. In other embodiments, the diameter of the limiting collar can be configured to expand from the limiting diameter to an expanded diameter in the expansion section at an average expansion angle relative to the longitudinal axis, the average expansion angle being at least 1 degree, preferably from 1 to 17.5 degrees, more preferably from 1 to 15 degrees, and even more preferably from 2 to 7 degrees.

[0035] It will be appreciated that the average expansion angle comprises the average or mean rate of growth of the expansion segment. In embodiments where the expansion segment comprises a linear slope, this will correspond substantially to the angle of the linear slope relative to the longitudinal axis. In embodiments where the expansion segment is curved or otherwise nonlinear, the average expansion angle is the average or mean angle formed by the surface within the expansion segment relative to the longitudinal axis. For example, for a curved surface, the average expansion angle will be the average angle of the curve. In an embodiment, the average expansion angle is a non-zero angle less than 17.5 degrees (i.e., an angle greater than zero to 17.5 degrees), preferably from 0.5 to 6 degrees, and more preferably from 3 to 5 degrees. In some embodiments, the average expansion angle is a non-zero angle less than 15 degrees, preferably a non-zero angle less than 10 degrees (i.e., an angle greater than zero to 10 degrees), preferably from 1 to 10 degrees, more preferably from 3 to 6 degrees, and even more preferably from 4 to 5 degrees. In some embodiments, the average expansion angle is from 1 to 17.5 degrees, preferably 1 to 15 degrees, more preferably from 1 to 12 degrees, even more preferably from 2 to 10 degrees, and even more preferably from 2 to 7 degrees. In some embodiments, the average expansion angle is from 3 to 10 degrees, preferably from 3 to 7 degrees. In some embodiments, the expansion angle is at least 3 degrees, more preferably at least 5 degrees. In some embodiments, the average expansion angle is about 5 degrees. The length of the expansion section can then be determined by the expansion angle and the size of the expanded diameter that the cone must reach.

[0036] The length of the restriction section of the restriction collar is preferably selected to provide sufficient spacing between the connection interface and the expansion section, thereby reducing the transmission of movement and other forces caused by the expansion and contraction changes experienced during the membrane hydrogenation change. In an embodiment, the restriction section is configured to extend from the connection interface to the transition section by at least 0.25D above the hydrogen separation membrane. In some embodiments, the restriction section is configured to extend from the connection interface to the transition section by 0.25D to 2D above the hydrogen separation membrane, preferably 0.25D to 1.5D, and more preferably 0.25D to 1D.

[0037] The expansion section provides a section where the hydrogen expansion of the hydrogen separation membrane can preferably gradually expand to a maximum expanded diameter D over the length of the hydrogen separation membrane (relative to the longitudinal axis). MH . Rapid expansion may still result in stress-elevated regions within the hydrogen separation membrane. Therefore, the expansion section preferably extends at least 0.2D relative to the longitudinal axis. A longer length may be advantageous. Therefore, in an embodiment, the expansion section extends at least 0.3D, preferably at least 0.4D, and more preferably at least 0.5D relative to the longitudinal axis.

[0038] It should also be understood that the transition section (and its surface) is located at the transition from the restricted diameter to the angled or curved section (ie, tapered or curved surface) of the expansion section. In embodiments, the average expansion angle includes the curve provided by the transition section (and included transition radius).

[0039] As described in detail above, when hydrogen is introduced into the hydrogen separation membrane, the hydrogenated hydrogen separation membrane (tube) will expand within the restriction collar, and the expansion will be constrained by the limits of the inner surface of the restriction collar. In the restriction section, the outer surface of the hydrogen separation membrane will abut against the inner wall of the section. Similarly, the outer surface of the hydrogen separation membrane will abut against the inner wall of the expansion section until the point of the diameter of the natural hydrogen expansion of the hydrogen separation membrane is reached. At the transition section, the outer surface of the hydrogen separation membrane after hydrogenation will have a complementary shape / curve around the angled or curved section (i.e., conical or curved surface) from the restriction diameter to the expansion section. Here, the membrane expands from the restriction diameter to the angled or curved section of the expansion section of the collar following the shape of the transition section. Therefore, the transition section provides a curved surface that is configured to prevent the formation of stress concentration points when the inner surface of the restriction collar transitions from the restriction diameter to the angled or curved section (i.e., conical or curved surface) of the expansion section. The curved surface of the transition section preferably has a radius of curvature of at least 0.1 D. In an embodiment, the transition radius is comprised from 0.1 D to 10 D, preferably from 0.5 D to 5 D, more preferably from 1 D to 5 D. In some embodiments, the transition radius is comprised from 0.5 D to 10 D, more preferably from 1 D to 10 D, more preferably from 2 D to 10 D.

[0040] The limiting collar is designed to extend from the connection interface of the hydrogen separation membrane, and preferably extends above the connection interface of the hydrogen separation membrane. In an embodiment, the limiting section of the limiting collar is configured to extend above the connection interface. In an embodiment, the limiting collar can also be configured to extend above the connection interface and extend above at least a portion of the connector. As taught above, the limiting diameter is preferably sized to be between 0.95D and 1.05D. In an embodiment, the limiting diameter includes 0.97D to 1.05D, preferably 0.99D to 1.05D, more preferably 1D to 1.05D. In some embodiments, the limiting diameter includes 0.98D to 1.05D, preferably 0.999D to 1.05D. In other embodiments, the limiting diameter includes 1D to 1.04D, preferably from 1D to 1.02D, more preferably from 1.005D to 1.01D. However, in some embodiments, the inner surface of this portion of the limiting section is preferably substantially parallel to the outer surface of the connection interface and the connector. In these embodiments, the inner diameter (limiting diameter) of this portion of the restriction section is greater than 1D to 1.05D, preferably greater than 1D to 1.04D, and more preferably greater than 1D to 1.02D. In a specific embodiment, the limiting diameter includes 1.005D to 1.01D. In some embodiments, the inner diameter (limiting diameter) of this portion of the restriction section is at least greater than 1D, more preferably greater than 1D to 1D plus 0.05mm. Therefore, the restriction section can mechanically constrain any expansion of the connection interface during hydrogenation expansion and circulation. It should be understood that circulation refers to the expansion and contraction stage of the hydrogen separation membrane when in operation.

[0041] In an embodiment, the restriction collar includes a collar fastening section that is configured to be fastened to a section of the connector. The restriction collar is preferably configured to extend above the connection interface to the restriction collar fastening section. Typically, the restriction collar extends from the restriction end above the connection interface to the restriction collar fastening section. The restriction collar fastening section typically includes a fastening structure that is configured to interconnect the restriction collar to a mating fastening structure of the connector. It should be understood that the mating fastening structure includes threads, interengageable ribs and grooves, rib and groove configurations, quick lock configurations, or other suitable interengaging fastening configurations. In some embodiments, the fastening structure includes a threaded connection that is configured to matingly fasten to threads located on the connector.

[0042] In an embodiment, the restriction collar further includes an end cap configured to form an end seal around the connector. The end cap preferably includes a sealing cover into which the connector is fastened, and the sealing cover fluid seals one end of the hydrogen separation membrane. In some embodiments, the end cap extends from the connection interface, preferably extends above the connection interface and surrounds the end of the connector located at the distal end of the connection interface. Typically, the end cap extends from the restriction section above the connection interface and surrounds the end of the connector located at the distal end of the connection interface. The end cap preferably includes a fastening structure configured to interconnect the restriction collar to a mating fastening structure of the connector. It should be understood that the mating fastening structure includes threads, mutually engageable ribs and grooves, rib and groove structures, quick locking structures or other suitable mutually engaging fastening structures. In some embodiments, the fastening structure includes a threaded connection that is configured to be matingly fastened to a thread located on the connector.

[0043] In an embodiment, the connector includes a tubular extension extending longitudinally away from the connection interface relative to the longitudinal axis. Here, the limiting collar includes a sealing section configured to extend above the tubular extension of the connector to the distal fastening end. Typically, the sealing section extends from the limiting section above the connection interface to the distal fastening end. The limiting collar in this embodiment further includes a compression fitting and at least one ferrule, the compression fitting being configured to be fastened to the distal fastening end of the sealing section, the ferrule being configured to seal around the segment of the tubular extension of the connector when the compression fitting is fastened to the distal fastening end of the sealing section. The ferrule includes a sealing member that is compressed by the compression fitting to create a fluid seal between the compression fitting and a portion of the tubular extension. The ferrule can have any suitable configuration and be made of any suitable material. In some embodiments, at least one ferrule includes a graphite ferrule. Similarly, the compression fitting can have any suitable configuration. In an embodiment, the compression fitting includes a sealing nut that is configured to be threadedly fastened to the distal fastening end of the sealing section. The sealing nut may include a compression type fitting or connector, such as a Hy-Lok type compression fitting or a Swagelok type fitting, which seals on the distal fastening end of the sealing section. As with the previous embodiments, the sealing section may also include a fastening structure that is configured to interconnect the restriction collar to a mating fastening structure of the connector. Likewise, it should be understood that the mating fastening structure includes threads, interengageable ribs and grooves, rib and groove configurations, quick lock configurations, or other suitable interengaging fastening configurations. In some embodiments, the fastening structure includes a threaded connection that is configured to matingly fasten to threads located on the connector.

[0044] The restriction collar may have any suitable overall shape and configuration. In an embodiment, the restriction collar comprises a tubular (preferably, substantially cylindrical) configuration. Similarly, the restriction collar may be formed from any suitable material. In an embodiment, the restriction collar is composed of at least one of: aluminum, an aluminum alloy, steel, stainless steel, nickel-chromium-iron alloy, brass, or a combination thereof.

[0045] The connector may be formed of any suitable metal or metal alloy to which the hydrogen separation membrane is to be mounted. In some embodiments, the connector is composed of at least one of steel, stainless steel, nickel-chromium-iron alloy, brass, Inconel, Incoloy, or a combination thereof. Examples of suitable materials include austenitic stainless steel, preferably 300 series stainless steel, such as 303, 304, or 316 stainless steel.

[0046] Metallic hydrogen separation membranes include metals that can achieve hydrogen separation by the following steps: dissociative chemical adsorption of hydrogen on the surface, followed by diffusion of hydrogen through the metal lattice to the opposite side of the membrane driven by a partial pressure drop, followed by recombination of hydrogen atoms and desorption of hydrogen from the permeate side. 2 / CO 2 Or other H 2 When the gas mixture is mixed with a gas, high permeability and recovery rate of hydrogen can be produced. In an embodiment, the hydrogen separation membrane includes a V group (5th group) base metal or metal alloy, preferably a vanadium, tantalum or niobium metal or metal alloy, more preferably vanadium or a vanadium alloy. In some embodiments, the hydrogen separation membrane can be formed by vanadium or a vanadium alloy. Generally, a specific vanadium metal or alloy is selected based on its applicability in a membrane separation device. In some embodiments, the hydrogen separation membrane includes a vanadium alloy, which includes vanadium, an aluminum content greater than 0 to 10at%, and a Ta content less than 0.01at%, and its ductility is greater than 10% elongation, preferably greater than 11% elongation. The vanadium alloy may further include a grain refining element selected from Ti, Cr, Fe, Ni or B, and its content is greater than 0 to 5at%, preferably between 0.2 and 4.5at%. In some embodiments, the content of the grain refining element is from 0.1 to 2at%, preferably from 0.1 to 2at%, and more preferably from 0.1 to 1at%. In some embodiments, the hydrogen separation membrane is coated with a Pd-based coating or a Pd—Au-based coating.

[0047] The hydrogen separation membrane can have any suitable configuration. In an exemplary embodiment, the hydrogen separation membrane is tubular. The tubular membrane can have any suitable size as described above. In some embodiments, the thin-walled tube includes a tube with an outer diameter between 2 and 25 mm, preferably between 3 and 20 mm and a wall thickness from 0.05 to 1 mm, preferably from 0.1 to 1 mm, as discussed in more detail below. In some embodiments, the wall thickness of the hydrogen separation membrane is from 0.1 to 1 mm, preferably from 0.2 to 0.8 mm, and more preferably from 0.2 to 0.5 mm.

[0048] The connector can have any suitable configuration. In many embodiments, the connector includes a metal fitting, such as a connection fitting or an end cap fitting, and preferably includes a metal fluid connection fitting, more preferably includes a metal gas connection fitting. In an exemplary embodiment, the connector is tubular. The connector can have any suitable size. In an embodiment, the wall thickness of the connector is from 1 to 5 mm, preferably from 1 to 3 mm, more preferably from 1 to 2 mm.

[0049] The connector structure of the connector can have any suitable configuration. In an embodiment, the connector structure includes an inclined or chamfered section that is configured to receive an end section of the hydrogen separation membrane thereon. In an exemplary embodiment, the connector structure includes an angled, inclined end of the connector structure having a reduced diameter. This forms a sloped or curved section to which the hydrogen separation membrane can be mounted. In some embodiments, the inclined or chamfered section includes a frustoconical section. In other embodiments, the connection interface includes a substantially flat end face of the hydrogen separation membrane that is arranged in a parallel adjacent or adjacent relationship to a substantially flat adjacent face of the connector structure.

[0050] The connection between the hydrogen separation membrane and the connector can be any suitable gas-tight connection between these bodies, such as (but not limited to) welding connection, brazing connection, threaded connection, O-ring sealing connection, etc. In some embodiments, the connection includes a welding connection or a brazing connection. In an exemplary embodiment, the connection includes a welding connection. The welding connection can be formed using any suitable welding technology, such as laser welding connection, arc welding connection (such as TIG) or electron beam welding. The welding connection preferably includes a continuous weld extending circumferentially around the connection interface and above the connection interface. This forms a continuous welding seal above the connection interface between the hydrogen separation membrane and the connector structure. In some embodiments, the weld is autogenous (no filler material is added). In other embodiments, filler materials are used in the welding connection, such as at least one of stainless steel, steel, aluminum silicon, copper, copper alloy, gold-silver alloy, nickel alloy or silver.

[0051] The connector and the restriction collar are typically distinct bodies that are connected together by mutually engageable fastening structures / means. However, it should be understood that in some embodiments, the connector may form a fixed or integral part of the restriction collar.

[0052] A second aspect of the present invention provides a method of coupling and sealing a hydrogen separation membrane to a metal connector, the method comprising:

[0053] mounting an end segment of a hydrogen separation membrane on or against a connector structure of a connector, the connector being formed of a metal different from the hydrogen separation membrane, the hydrogen separation membrane having an outer diameter (D) about the longitudinal axis, the hydrogen separation membrane and the connector structure being in contact at a connection interface in which an end face of the hydrogen separation membrane is proximate, substantially abuts or overlaps an adjacent face of the connector structure;

[0054] coupling the hydrogen separation membrane to the connector structure to couple and seal the hydrogen separation membrane to the connector through the connection interface; and

[0055] positioning a confinement collar over the hydrogen separation membrane to extend at least from the connection interface and axially over the hydrogen separation membrane relative to the longitudinal axis,

[0056] wherein the restriction collar comprises: an expansion section, the expansion section being configured to extend axially from a restriction end to an expanded diameter above the hydrogen separation membrane relative to the longitudinal axis, the restriction end being configured to extend around the hydrogen separation membrane at or near the connection interface relative to the longitudinal axis and having an inner surface defining a restriction diameter (C), the inner surface being configured to extend around an outer surface of the hydrogen separation membrane; the expansion section comprising a transition section extending from the restriction end and comprising a curved surface having a transition radius of at least 0.1D;

[0057] And wherein the expansion section comprises an angled or curved section in which the diameter of the restraining collar expands from the restraining diameter C to an expanded diameter comprising at least 1.01D.

[0058] In some embodiments, this second aspect of the invention provides a method of bonding and sealing a hydrogen separation membrane to a metal connector, the method comprising:

[0059] mounting an end segment of a hydrogen separation membrane on or against a connector structure of a connector, the connector being formed of a metal different from the hydrogen separation membrane, the hydrogen separation membrane having an outer diameter (D) about the longitudinal axis, the hydrogen separation membrane and the connector structure being in contact at a connection interface in which an end face of the hydrogen separation membrane is proximate, substantially abuts or overlaps an adjacent face of the connector structure;

[0060] coupling the hydrogen separation membrane to the connector structure to couple and seal the hydrogen separation membrane to the connector through the connection interface; and

[0061] positioning a confinement collar over the hydrogen separation membrane to extend at least from the connection interface and axially over the hydrogen separation membrane relative to the longitudinal axis,

[0062] Wherein, the limiting collar comprises:

[0063] an expansion section configured to extend axially from a restricted end to an expanded diameter above the hydrogen separation membrane relative to the longitudinal axis, the restricted end configured to extend around the hydrogen separation membrane at or near the connection interface relative to the longitudinal axis and having an inner surface defining a restricted diameter (C) configured to extend around an outer surface of the hydrogen separation membrane;

[0064] wherein the expansion section comprises a transition section extending from the limiting end and comprising a curved surface having a transition radius of at least 0.1D;

[0065] and wherein the expansion section comprises an angled or curved section in which:

[0066] The diameter of the restraining collar expands from the restraining diameter to the expanded diameter at an average expansion angle relative to the longitudinal axis, the average expansion angle ranging from greater than zero degrees to 17.5 degrees,

[0067] The expanded diameter comprises at least 1.01D, and

[0068] The expansion section extends at least 0.1D relative to the longitudinal axis.

[0069] In the method, first, the hydrogen separation membrane is joined to a metal (e.g., stainless steel) connector using a suitable joining or connecting method, such as a welding method such as laser welding, arc welding methods (e.g., TIG), or electron beam welding. Next, a specially constructed confinement collar is positioned near or above the connection interface, the confinement collar being configured to extend above the hydrogen separation membrane to constrain expansion of the membrane near the connection interface / joint during hydrogenation of the hydrogen separation membrane.

[0070] It should be understood that this second aspect of the invention may include any one or combination of the above features associated with the restriction collar described in relation to the first aspect of the invention. Similarly, the restriction collar has features defined in the fifth aspect of the invention below, the disclosure of which should be understood to apply equally to this second aspect of the invention. Furthermore, in embodiments, the method according to this second aspect of the invention may use the coupling and sealing device according to the first aspect of the invention and / or may be used to form the coupling and sealing device according to the first aspect of the invention.

[0071] Likewise, the confinement collar includes a confinement section that moves the expansion zone of the hydrogen separation membrane away from the weld joint, thereby reducing strain on the weld joint and allowing the seal to remain intact during the expansion and contraction changes experienced by the membrane during the hydrogenation changes. In addition, the confinement collar includes an expansion section that allows the hydrogenated hydrogen separation membrane to expand (preferably gradually) to its naturally hydrogenated expanded diameter as the hydrogen separation membrane extends away from the connection within the confinement collar along the longitudinal axis XX.

[0072] It has been found that the use of a restraining collar to protect the connection and seal produces a weld seal that can withstand the volume expansion of the Pd-coated hydrogen separation metal membrane as it absorbs hydrogen through the metal lattice during hydrogen diffusion. This occurs as part of the start-up of membrane operation, when the hydrogen partial pressure is gradually increased from zero to the final operating conditions. The fluid seal formed by the connection interface seal is also maintained during the subsequent expansion and contraction experienced by the tubular hydrogen separation metal membrane during the hydrogenation change, that is, during membrane cycling during operation (when changing the operating hydrogen partial pressure and temperature) and desorption of hydrogen from the membrane before shutdown.

[0073] Likewise, the connector may include various segments extending above the connection interface and the connector. In some embodiments, the connector includes a tubular extension extending longitudinally away from the connection interface, and the restricting collar includes a sealing segment configured to extend above the tubular extension of the connector to a distal fastening end. In these embodiments, the method further includes:

[0074] A compression fitting is fastened to the distal fastening end of the sealing segment, the compression fitting including at least one ferrule that seals around a segment of the tubular extension of the connector when the compression fitting is fastened to the distal fastening end of the sealing segment.

[0075] As described for the first aspect of the present invention, the ferrule includes a sealing member that is compressed by the compression fitting to create a fluid seal between the compression fitting and a portion of the tubular extension. The ferrule can have any suitable configuration and can be made of any suitable material. In some embodiments, at least one ferrule includes a graphite ferrule. Similarly, the compression fitting can have any suitable configuration. In an embodiment, the compression fitting includes a sealing nut that is configured to be threadedly fastened to the distal fastening end of the sealing section. The sealing nut can include a compression-type fitting or connector, such as a Hy-Lok type compression fitting or a Swagelok type fitting, which seals on the distal fastening end of the sealing section. As with the previous embodiment, the sealing section can also include a fastening structure that is configured to interconnect the limiting collar to a mating fastening structure of the connector. Similarly, it should be understood that the mating fastening structure includes threads, mutually engageable ribs and grooves, rib and groove structures, quick locking structures, or other suitable mutually engaging fastening structures. In some embodiments, the fastening structure includes a threaded connection configured to matingly fasten to threads located on the connector.

[0076] The connector and hydrogen separation membrane may have the features defined above for the first aspect of the invention.The connector may be formed from any suitable metal, such as at least one of steel, stainless steel, Inconel, brass, Inconel, Incoloy or a combination thereof.

[0077] Similarly, the hydrogen separation membrane may include any suitable hydrogen separation metal or alloy. In an embodiment, the hydrogen separation membrane includes a V-group base metal or metal alloy, preferably a vanadium, tantalum or niobium metal or metal alloy, more preferably a vanadium or vanadium alloy. In some embodiments, the hydrogen separation membrane may be formed of vanadium or a vanadium alloy, such as a vanadium alloy including vanadium, an aluminum content greater than 0 to 10 at%, and a content of less than 0.01 at%, and a ductility greater than 10% elongation, preferably greater than 11% elongation. In some embodiments, the vanadium alloy further includes a grain refining element selected from Ti, Cr, Fe, Ni or B, and its content is greater than 0 to 5 at%, preferably between 0.2 and 4.5 at%. The hydrogen separation membrane may also be coated with a Pd-based coating or a Pd-Au-based coating. In many embodiments, the hydrogen separation membrane is tubular. Similarly, in many embodiments, the connector is tubular. The connector structure may have any suitable configuration. In an embodiment, the connector structure includes an inclined or chamfered section configured to receive an end section of the hydrogen separation membrane thereon.

[0078] The connection between the hydrogen separation membrane and the connector can be any suitable gas-tight connection between these bodies, such as (but not limited to) welding connection, brazing connection, threaded connection, O-ring sealing connection, etc. In some embodiments, the connection includes a welding connection or a brazing connection. In an exemplary embodiment, the connection includes a welding connection. The welding connection can be formed using any suitable welding technology, such as laser welding connection, arc welding connection (such as TIG) or electron beam welding. The welding connection preferably includes a continuous weld extending circumferentially around the connection interface and above the connection interface. This forms a continuous welding seal above the connection interface between the hydrogen separation membrane and the connector structure. In some embodiments, the weld is autogenous (no filler wire is added). In other embodiments, a filler material is used in the welding connection, such as at least one of aluminum silicon, copper, copper alloy, gold-silver alloy, nickel alloy or silver.

[0079] The connector and the restriction collar are typically distinct bodies that are connected together by mutually engageable fastening structures / means. However, it should be understood that in some embodiments, the connector may form a fixed or integral part of the restriction collar.

[0080] A third aspect of the present invention also relates to a gas separation membrane system comprising a hydrogen separation membrane coupled and sealed to a connector structure using a coupling and sealing device according to the first aspect of the present invention and / or prepared by the method according to the second aspect of the present invention.

[0081] An application of the sealing and coupling device of the present invention is to enable the assembly of a hydrogen separation tubular membrane into a catalytic membrane reactor (CMR) or membrane separator for selective separation of hydrogen from a mixed gas stream (having hydrogen and other gases) to produce high purity hydrogen in the permeate stream from the membrane (suitable for FCEV refueling applications). The collar and associated method provide a means of coupling the hydrogen separation membrane to other metal structures (tube connections, tube ends, etc.) to form a hydrogen separation system while maintaining sealing integrity, i.e., maintaining mechanical integrity / robustness, over multiple operating cycles.

[0082] A fourth aspect of the present invention provides at least one of a catalytic membrane reactor (CMR) or a membrane separator, comprising at least one hydrogen separation membrane, which is connected and sealed to a connector using a connecting and sealing device according to the first aspect of the present invention and / or prepared by the method according to the second aspect of the present invention.

[0083] The membranes of the present invention may have any suitable configuration, which is selected based on the particular advantages that the configuration can provide for a particular CMR or membrane separator configuration.

[0084] CMR is essentially a two-dimensional device that delivers synthesis gas or alternatively ammonia (if catalytic cracking ammonia) along one dimension through a catalyst bed adjacent to the membrane. Flat membranes are easier and cheaper to produce than tubular membranes, but have a larger sealing area because the membrane is sealed around its outer edge. This sealing configuration provides a larger sealing area and is therefore prone to leakage between the raffinate and the permeate gas stream. Tubular membranes enable the use of tubular CMRs, so the sealing area can be reduced. In a tubular reactor, seals are required only at each end of the tube. The coupling and sealing methods of the present invention can be used to provide these seals. Similar considerations also apply to the construction of membrane separators.

[0085] In some embodiments, the hydrogen separation membrane of the present invention has a tubular structure, preferably including a tube. The tubular membrane can have any suitable size as described above. In some embodiments, the thin-walled tube includes a tube with an outer diameter between 2 and 25 mm, preferably between 3 and 20 mm and a wall thickness from 0.05 to 1 mm, preferably from 0.1 to 10 mm. In an exemplary body, the tubular membrane includes a thin-walled tube, which includes a vanadium alloy, the vanadium alloy includes vanadium, aluminum with a content greater than 0 to 10 at% and Ta with a content less than 0.01 at%, and its ductility is greater than 10% elongation, preferably greater than 11% elongation. In some embodiments, the hydrogen separation membrane is coated with a Pd-based coating or a Pd-Au-based coating.

[0086] It will be appreciated that the alloy content and mechanical properties of the hydrogen separation membrane of the fourth aspect of the invention are the same as described above for the first and second aspects of the invention and will be understood to apply equally to this aspect of the invention.

[0087] A fifth aspect of the present invention provides a hydrogen separation membrane confinement collar, the hydrogen separation membrane confinement collar being configured to extend over a hydrogen separation membrane, the confinement collar being configured to extend from a connection interface between a hydrogen separation membrane and a connector and to extend over the hydrogen separation membrane, the confinement collar having a longitudinal axis and comprising:

[0088] an expansion section configured to extend axially from a restricted end to an expanded diameter above the hydrogen separation membrane relative to the longitudinal axis, the restricted end defining a restricted diameter (C) configured to extend around the hydrogen separation membrane relative to the longitudinal axis at or near the connection interface and having an inner surface extending around an outer surface of the hydrogen separation membrane,

[0089] wherein the expansion section comprises a transition section extending from the limiting end and comprising a curved surface having a transition radius of at least 0.1C,

[0090] And wherein the expansion section includes an angled or curved section in which the diameter of the limiting collar expands from the limiting diameter to the expanded diameter at an average expansion angle relative to the longitudinal axis, the average expansion angle includes a non-zero angle less than 17.5 degrees, and the expanded diameter includes at least 1.01C.

[0091] As with the first aspect, the inventors have found that the connection between the metal hydrogen separation membrane and the connector itself may be susceptible to failure (causing leakage) and may not be able to adapt to changes in membrane hydrogenation as expected. The limiting collar of the fifth aspect of the present invention is designed to constrain the volume expansion of the metal hydrogen separation (hydrogen selective) tubular membrane at or near the connection joint between the hydrogen separation membrane and the connector when exposed to hydrogen. The limiting collar has an expansion section that transitions from a restricted diameter at the restricted end of the expansion section to a larger expanded diameter, which allows the hydrogenated hydrogen separation membrane to expand (preferably gradually / stepwise) to its naturally hydrogenated expanded diameter as the hydrogen separation membrane extends away from the connection between the hydrogen separation membrane and the connector along the longitudinal axis within the limiting collar.

[0092] It should be understood that the restriction collar in the coupling and sealing device of the first aspect of the invention shares many similar features with the restriction collar that will be described with respect to this fifth aspect of the invention, and that the following disclosure of the restriction collar of the fifth aspect of the invention is equally applicable to similar features of the restriction collar including features of the coupling and sealing device of the first aspect of the invention, and vice versa.

[0093] In many embodiments, the limiting end of the limiting collar includes a limiting section that is configured to move the expansion zone of the hydrogen separation membrane away from the connection interface / joint, thereby reducing the strain on the weld joint. In these embodiments, the limiting section is configured to extend axially from the connection end to the expansion section above the hydrogen separation membrane relative to the longitudinal axis, and the limiting section has an inner surface extending around the longitudinal axis with a limiting diameter. The transition section extends from a transition area, position, point, etc. between the limiting section and the expansion section. The transition section here extends from a transition area, position or point where the limiting section intersects the expansion section.

[0094] It will be appreciated that the transition section includes a curved surface that forms a transition surface from the restricted end / restricted section to the expansion section of the collar. The curved surface has a curve that follows a radial curve of at least 0.1C. It will be appreciated that the curve typically includes only a small segment or portion of the radial curve, wherein the curve joins the restricted end / restricted section and the end of the angled or curved section of the expansion section and forms a transition surface between the restricted end / restricted section and the angled or curved section of the expansion section.

[0095] It should also be understood that the outer diameter D is the outer diameter of the hydrogen separation membrane when the hydrogen separation membrane is in an unhydrogenated state (ie, not in a hydrogenated expanded state). The outer diameter depends on the size of the membrane used for hydrogen separation and thus may have any suitable dimensions.

[0096] The limiting diameter C is preferably sized to be between 0.95D and 1.05D. In an embodiment, the limiting diameter comprises 0.97D to 1.05D, preferably 0.99D to 1.05D, more preferably 1D to 1.05D. In some embodiments, the limiting diameter comprises 0.98D to 1.05D, preferably 0.999D to 1.05D. In some embodiments, the limiting diameter comprises 1D to 1.04D, preferably from 1D to 1.02D, more preferably from 1.005D to 1.01D.

[0097] The length of the restriction section of the restriction collar is preferably selected to provide sufficient spacing of the connection interface from the expansion section, thereby reducing the transmission of movement and other forces caused by the expansion and contraction changes experienced during the membrane hydrogenation change. In an embodiment, the restriction section is configured to extend from the connection interface to the transition section by at least 0.25° above the hydrogen separation membrane. In some embodiments, the restriction section is configured to extend from the connection interface to the transition section by 0.25° to 2°, preferably 0.25° to 1.5°, and more preferably 0.25° to 1° above the hydrogen separation membrane.

[0098] The expanded diameter D2 is selected to be larger than the outer diameter D of the metal hydrogen separation membrane when the metal hydrogen separation membrane is in an unhydrogenated state, and the limiting diameter C. In an embodiment, the expanded diameter D2 is at least 1.01C, preferably at least 1.02C. In some embodiments, the expanded diameter D2 is selected to be larger than the maximum diameter (diameter D2) of the hydrogen separation membrane after hydrogenation. MH ). Hydrogen separation (hydrogen selective) membrane tubes such as vanadium-based hydrogen separation membranes may expand in volume by at least about +10%, more typically +13%, and in linear expansion in one direction / axis by up to 5% - e.g., diameter - when hydrogenated at conventional operating temperatures / pressures, compared to ambient conditions without hydrogen. Therefore, in embodiments, the expanded diameter D2 is at least 1.05D to accommodate this linear expansion when the hydrogen separation membrane is hydrogenated. In embodiments, the expanded diameter D2 is at least 1.07C, preferably at least 1.08C, and more preferably at least 1.1C. In some embodiments, the expanded diameter D2 is at least 1.12C, and preferably at least 1.2C.

[0099] Similarly, the maximum diameter of the hydrogen separation membrane after hydrogenation (diameter D MH ) is greater than the limiting diameter C of the limiting section of the limiting collar. Similarly, the maximum diameter (diameter D) of the hydrogen separation membrane after hydrogenation MH) is larger than the outer diameter D of the metal hydrogen separation membrane when the metal hydrogen separation membrane is in an unhydrogenated state - this can be understood from the nature of the hydrogenation process.

[0100] As described with respect to the first aspect, the expansion section may include a linear, curved or other shaped or contoured surface that expands generally from a restricted diameter to an expanded diameter. The shape may have an uneven or irregular shape or contour. However, preferably, the shape is generally regular and / or smooth, for example, with a linear expansion angle or a smooth curve. In the case where the expansion section includes a curve, the curve may include a continuous curve including a transition section. In some embodiments, the transition section follows the same or similar curve as the entire surface of the expansion section and may share a common radius. Here, the transition section and the angled or curved section of the expansion section following the transition section have the same or similar curve and may share a common radius.

[0101] The change from the limiting diameter to the expanded diameter in the expansion section can have any suitable shape. In some embodiments, the expansion section includes an inclined or curved surface from the transition section to the expanded diameter. In an embodiment, the expansion section includes an inclined or tapered surface. For example, the diameter of the limiting collar can be configured to expand from the limiting diameter to the expanded diameter in the expansion section at an average expansion angle relative to the longitudinal axis, the average expansion angle comprising a non-zero angle of less than 17.5 degrees (i.e., an angle greater than zero to 17.5 degrees), preferably from 0.5 to 6 degrees, and more preferably from 3 to 5 degrees. In some embodiments, the diameter of the limiting collar can be configured to expand from the limiting diameter to the expanded diameter in the expansion section at an average expansion angle relative to the longitudinal axis, the average expansion angle comprising a non-zero angle of less than 15 degrees, preferably a non-zero angle of less than 10 degrees (i.e., an angle greater than zero to 10 degrees), preferably an angle from 1 to 10 degrees, more preferably from 3 to 6 degrees, and more preferably from 4 to 5 degrees. In other embodiments, the diameter of the limiting collar can be configured to expand from the limiting diameter to an expanded diameter in the expansion section at an average expansion angle relative to the longitudinal axis, the average expansion angle being at least 1 degree, typically from 1 to 17.5 degrees, preferably from 1 to 15 degrees, and more preferably from 2 to 7 degrees.

[0102] It will be appreciated that the average expansion angle comprises the average or mean rate of growth / expansion of the expansion segment relative to the longitudinal axis. In embodiments where the expansion segment comprises a linear slope, this will correspond substantially to the angle of the linear slope. In other embodiments where the expansion segment is curved or otherwise non-linear, the average expansion angle will be the average or mean angle formed by the surfaces within the expansion segment. For example, for a curved surface, the average expansion angle will be the average angle of the curve.

[0103] In an embodiment, the average expansion angle is a non-zero angle of less than 17.5 degrees (i.e., an angle greater than zero to 17.5 degrees), preferably from 0.5 to 6 degrees, more preferably from 3 to 5 degrees. In some embodiments, the average expansion angle is a non-zero angle of less than 15 degrees, preferably a non-zero angle of less than 10 degrees (i.e., an angle greater than zero to 10 degrees), preferably from 1 to 10 degrees, more preferably from 3 to 6 degrees, and more preferably from 4 to 5 degrees. In some embodiments, the average expansion angle is from 1 to 17.5 degrees, preferably 1 to 15 degrees, more preferably from 1 to 12 degrees, more preferably from 2 to 10 degrees, and more preferably from 2 to 7 degrees. In some embodiments, the average expansion angle is from 3 to 10 degrees, preferably from 3 to 7 degrees. In some embodiments, the expansion angle is at least 1 degree, more preferably at least 2 degrees, more preferably at least 3 degrees, and more preferably at least 5 degrees. In some embodiments, the average expansion angle is about 5 degrees. The length of the expansion section will then be determined by the expansion angle and the size of the expanded diameter that the taper must reach. However, the expansion section extends at least 0.1D relative to the longitudinal axis.

[0104] Another way to express the rate at which the expansion section expands is to express it as the radial expansion rate of the inner radius of the collar from the restricted end to the expanded diameter of the collar. In some embodiments, the maximum radial expansion rate is less than 0.315 mm / mm, preferably from 0.0087 mm / mm to 0.105 mm / mm, more preferably from 0.052 mm / mm to 0.087 mm / mm. In some embodiments, the maximum radial expansion rate is less than 0.27 mm / mm, preferably less than 0.176 mm / mm.

[0105] The expansion section provides a section where the expansion of the hydrogen separation membrane can preferably gradually expand to a maximum expanded diameter over the length of the hydrogen separation membrane (relative to the longitudinal axis). Rapid expansion may still result in stress elevation regions within the hydrogen separation membrane. Therefore, the expansion section preferably extends at least 0.2C relative to the longitudinal axis. A longer length may be advantageous. Therefore, in an embodiment, the expansion section extends at least 0.3C, preferably at least 0.4C, and more preferably at least 0.5C relative to the longitudinal axis.

[0106] It should also be understood that the transition section is located at the transition from the restricted diameter to the angled or curved section (ie, tapered or curved surface) of the expansion section. In an embodiment, the average expansion angle includes the curve provided by the transition section (and includes the transition radius).

[0107] As described in detail above, when hydrogen is introduced into the hydrogen separation membrane, the hydrogenated hydrogen separation membrane (tube) will expand within the restriction collar, and the expansion will be constrained by the limits of the inner surface of the restriction collar. In the restriction section, the outer surface of the hydrogen separation membrane will abut against the inner wall of the section. Similarly, the outer surface of the hydrogen separation membrane will abut against the inner wall of the expansion section until the point of the diameter of the natural hydrogen expansion of the hydrogen separation membrane is reached. At the transition section, the outer surface of the hydrogen separation membrane after hydrogenation will have a complementary shape / curve around the angled or curved section (i.e., conical or curved surface) from the restriction diameter to the expansion section. Here, the membrane expands from the restriction diameter to the angled or curved section of the expansion section of the collar following the shape of the transition section. Therefore, the transition section provides a curved surface that is configured to prevent the formation of stress concentration points when the inner surface of the restriction collar transitions from the restriction diameter to the angled or curved section (i.e., conical or curved surface) of the expansion section. The curved surface of the transition section preferably has a radius of curvature of at least 0.1C. In an embodiment, the transition radius is comprised from 0.1C to 10C, preferably from 0.5C to 5C, more preferably from 1C to 5C. In some embodiments, the transition radius is comprised from 0.5C to 10C, more preferably from 1C to 10C, more preferably from 2C to 10C.

[0108] The restriction collar is designed to extend from, and preferably extend over, the connection interface of the hydrogen separation membrane. In an embodiment, the restriction section of the restriction collar is configured to extend over the connection interface. In an embodiment, the restriction collar may also be configured to extend over the connection interface and over at least a portion of the connector.

[0109] In an embodiment, the restriction collar includes a collar fastening section that is configured to be fastened to a section of the connector. The restriction collar is preferably configured to extend above the connection interface to the restriction collar fastening section. Typically, the restriction collar extends from the restriction end to the restriction collar fastening section above the connection interface. The collar fastening section is configured to be fastened to a section of the connector and includes a fastening structure that is configured to interconnect the restriction collar to a mating fastening structure of the connector. It should be understood that the mating fastening structure may include threads, interengageable ribs and grooves, rib and groove configurations, quick-lock configurations, or other suitable interengaging fastening configurations. In some embodiments, the fastening structure includes a threaded connection that is configured to matingly fasten to a thread located on the connector.

[0110] In an embodiment, the restriction collar further includes an end cap configured to form an end seal around the connector. The end cap preferably includes a sealing cover into which the connector is fastened, and the sealing cover fluid seals one end of the hydrogen separation membrane. In some embodiments, the end cap extends from the connection interface, preferably extends above the connection interface and surrounds the end of the connector located at the distal end of the connection interface. Typically, the end cap extends from the restriction section above the connection interface and surrounds the end of the connector located at the distal end of the connection interface. The end cap preferably includes a fastening structure configured to interconnect the restriction collar to a mating fastening structure of the connector. It should be understood that the mating fastening structure includes threads, mutually engageable ribs and grooves, rib and groove structures, quick locking structures or other suitable mutually engaging fastening structures. In some embodiments, the fastening structure includes a threaded connection that is configured to be matingly fastened to a thread located on the connector.

[0111] In an embodiment, the connector includes a tubular extension extending longitudinally away from the connection interface relative to the longitudinal axis. Here, the limiting collar includes a sealing section, which is configured to extend above the connector (preferably, above the tubular extension of the connector) to the distal fastening end. Typically, the sealing section extends from the limiting section to the distal fastening end above the connection interface. The limiting collar in this embodiment further includes a compression fitting and at least one ferrule, the compression fitting is configured to be fastened to the distal fastening end of the sealing section, and the ferrule is configured to seal around the section of the connector (preferably, the section of the tubular extension of the connector) when the compression fitting is fastened to the distal fastening end of the sealing section. The ferrule includes a sealing member, which is compressed by the compression fitting to create a fluid seal between the compression fitting and a portion of the tubular extension. The ferrule can have any suitable configuration and can be made of any suitable material. In some embodiments, at least one ferrule includes a graphite ferrule. Similarly, the compression fitting can have any suitable configuration. In an embodiment, the compression fitting includes a sealing nut that is configured to be threadedly fastened to the distal fastening end of the sealing section. The sealing nut may include a compression-type fitting or connector, such as a Hy-Lok-type compression fitting or a Swagelok-type fitting, which seals on the distal fastening end of the sealing section. As with the previous embodiments, the sealing section may also include a fastening structure that is configured to interconnect the limiting collar to a mating fastening structure of the connector. Likewise, it should be understood that the mating fastening structure includes threads, interengageable ribs and grooves, rib and groove structures, quick locking structures, or other suitable interengaging fastening structures. In some embodiments, the fastening structure includes a threaded connection that is configured to matingly fasten to threads located on the connector.

[0112] The restriction collar may have any suitable overall shape and configuration. In an embodiment, the restriction collar comprises a tubular (preferably, substantially cylindrical) configuration. Similarly, the restriction collar may be formed from any suitable material. In an embodiment, the restriction collar is composed of at least one of: aluminum, an aluminum alloy, steel, stainless steel, nickel-chromium-iron alloy, brass, or a combination thereof.

[0113] A sixth aspect of the present invention provides a hydrogen separation membrane confinement collar, which, when used over a joint between a hydrogen separation membrane and a metal connector, is configured to extend from a connection interface between the hydrogen separation membrane and the connector and over the hydrogen separation membrane, the confinement collar having a longitudinal axis and comprising:

[0114] an expansion section configured to extend axially from a restricted end to an expanded diameter above the hydrogen separation membrane relative to the longitudinal axis, the restricted end configured to extend around the hydrogen separation membrane relative to the longitudinal axis at or near the connection interface and having an inner surface defining a restricted diameter (C) configured to extend around an outer surface of the hydrogen separation membrane,

[0115] wherein the expansion section comprises a transition section extending from the limiting end and comprising a curved surface having a transition radius of at least 0.1C,

[0116] And wherein the expansion section comprises an angled or curved section extending from the transition section, in which section: the diameter of the restraining collar expands from the restraining diameter to the expanded diameter comprising at least 1.01C.

[0117] It should be understood that the restriction collars of the first and fifth aspects of the present invention share many similar features with the restriction collar of the sixth aspect of the present invention, and the above disclosure of the first and fifth aspects of the present invention is also applicable to similar features of the restriction collar of the sixth aspect of the present invention.

[0118] A seventh aspect of the present invention provides a method for coupling and sealing a hydrogen separation membrane to a metal connector, the method comprising:

[0119] mounting an end segment of a metal hydrogen separation membrane on or against a connector structure of a connector, the connector being formed of a metal different from the hydrogen separation membrane, the hydrogen separation membrane having an outer diameter (D) about the longitudinal axis, the hydrogen separation membrane and the connector structure being in contact at a connection interface in which an end face of the hydrogen separation membrane is proximate, substantially abuts or overlaps an adjacent face of the connector structure;

[0120] coupling the hydrogen separation membrane to the connector structure to couple and seal the hydrogen separation membrane to the connector through the connection interface; and

[0121] A confinement collar according to the fifth or sixth aspect of the invention is positioned above the hydrogen separation membrane to extend at least from the connection interface and to extend axially above the hydrogen separation membrane relative to the longitudinal axis.

[0122] It should be understood that this seventh aspect of the invention may include any one or combination of the features described above in connection with the restriction collar including the fifth and sixth aspects of the invention. It should also be understood that this seventh aspect of the invention may include any one or combination of the features described above in connection with the method including the second aspect of the invention. Furthermore, in embodiments, the method according to this seventh aspect of the invention may be used to form a coupling and sealing device according to the first aspect of the invention.

[0123] An eighth aspect of the present invention provides a coupling and sealing device for coupling and sealing a hydrogen separation membrane to a metal connector, the coupling and sealing device comprising:

[0124] a metal hydrogen separation membrane mounted on or against a connector structure of the connector about a longitudinal axis, the connector being formed of a metal different from the hydrogen separation membrane, the hydrogen separation membrane having an outer diameter (D) about the longitudinal axis, the hydrogen separation membrane and the connector structure being in contact at a connection interface in which an end face of the hydrogen separation membrane is proximate to, substantially abuts against, or overlaps an adjacent face of the connector structure;

[0125] a connecting portion connecting the hydrogen separation membrane and the connector structure around the connection interface; and

[0126] According to the confinement collar of the fifth or sixth aspect of the present invention, the confinement collar is configured to extend at least from the connection interface and to extend axially above the hydrogen separation membrane relative to the longitudinal axis.

[0127] It should be understood that this eighth aspect of the invention may include any one or combination of the features described above in connection with the restriction collar including the fifth or sixth aspects of the invention. It should also be understood that this eighth aspect of the invention may include any one or combination of the features described above in connection with the coupling and sealing device according to the first aspect of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0128] The present invention will now be described with reference to the figures in the accompanying drawings, which illustrate certain preferred embodiments of the invention, and in which:

[0129] Figure 1A cross-sectional view illustrating a first embodiment of the coupling and sealing device of the present invention.

[0130] Figure 2 Provided Figure 1 Cross-sectional view of the restraining collar of the illustrated embodiment.

[0131] Figure 2A Provided Figure 1 A cross-sectional view of an alternative embodiment of a restraining collar to the illustrated embodiment including a curved expansion section.

[0132] Figure 3 Provided Figure 1 and Figure 2 A perspective view of the restraining collar of the illustrated embodiment.

[0133] Figure 3A A cross-sectional view of a second embodiment of the coupling and sealing device of the present invention is provided.

[0134] Figure 4 A cross-sectional view illustrating a third embodiment of the coupling and sealing device of the present invention.

[0135] Figure 5 Provided Figure 4 Cross-sectional view of the restraining collar of the illustrated embodiment.

[0136] Figure 6 Provided Figure 4 and Figure 5 A perspective view of the restraining collar of the illustrated embodiment.

[0137] Figure 7 A cross-sectional view illustrating a fourth embodiment of the coupling and sealing device of the present invention.

[0138] Figure 8 Provided Figure 7 A perspective view of the restraining collar in the illustrated embodiment.

[0139] Fig. 9 The steps involved in forming a flat joining surface on the end of a vanadium based tube for use in the coupling and sealing device of the present invention are illustrated.

[0140] Fig.10 An optical microscope image of a cross section of a welded connection between an end section of a vanadium-based membrane and a connector structure of a connector is provided.

[0141] Fig.11 A radial displacement model is provided to illustrate the radial displacement of the vanadium-based film when it is hydrogenated. Figure 1 , Figure 2 , Figure 2A and Figure 3 How much displacement occurs within the restraining collar of the coupling and sealing device shown in FIG.

[0142] Fig.12 Provided that when the vanadium-based film is hydrogenated, Figures 1 to 3 Results of the axial and hoop stress model on the welded connection of the coupling and sealing device shown in , showing (A) the axial stress of the membrane; (B) the hoop stress of the weld; and (C) the axial stress of the weld.

[0143] Fig.13 When the vanadium-based film is hydrogenated, Figure 1 , Figure 2 , Figure 2A and Figure 3 The connection and sealing device shown in the figure shows the relationship between the axial stress on the outer surface of the weld and the distance from the weld connection (A); and the relationship between the hoop stress on the outer surface of the weld and the distance from the weld connection (B).

[0144] Fig.14 When the vanadium-based film is hydrogenated, Figure 1 , Figure 2 , Figure 2A and Figure 3 The connection and sealing device shown in, the relationship between the axial stress of the inner surface of the vanadium film at the connection interface and the distance from the welded connection (A); and the relationship between the hoop stress of the inner surface of the vanadium film at the connection interface and the distance from the welded connection (B).

[0145] Fig.15 Stress modeling results are provided for the longitudinal bending stress at the outer surface of the membrane modeled starting from the end of the transition section in the expansion section, with average expansion angles modeled at 1, 3, 5, 6, 10, and 17.5 degrees.

[0146] Fig.16 Stress modeling results are provided for the longitudinal bending stress at the outer surface of the membrane modeled from the beginning of the transition section, with average expansion angles of 1, 3, 5, 6, 10, and 17.5 degrees.

[0147] Fig.17 A graph of radial expansion rate (mm / mm) versus distance from the start of the transition segment radius (mm) is provided, illustrating different transition segment lengths required for a 5 mm radius transition segment for different maximum expansion rates for angled or curved segments. DETAILED DESCRIPTION

[0148] The present invention relates to an apparatus for coupling and sealing a metal hydrogen separation membrane to a connector formed of a different metal (eg, stainless steel), which includes a connection between the hydrogen separation membrane and the connector.

[0149] As mentioned above, the present invention relates to a method for separating H 2 / CO 2Or other H 2 A metal membrane that produces high permeability and recovery of hydrogen when a gas mixture is used. In an embodiment, the hydrogen separation membrane comprises a Group 5 (V) base metal or metal alloy, such as vanadium, tantalum or niobium metal or metal alloy. For the remainder of this specification, a hydrogen separation membrane formed by vanadium or a vanadium alloy is used as an example for explanation. However, it should be understood that the present invention can be more generally applied to other metal hydrogen separation membranes, particularly other Group 5 metals or metal alloys.

[0150] As described in the background, vanadium-based hydrogen-selective membrane tubes can have a linear (dimensional) expansion of up to about +5% and a volume expansion of up to about +15% when hydrogenated at conventional operating temperatures / pressures, compared to ambient conditions without hydrogen. Other metallic hydrogen-selective membrane tubes, such as membrane tubes formed from Group 5 metals and their alloys, have similar linear and volume expansions when hydrogenated. This expansion can produce significant strains and stresses on the welded connection between the vanadium-based membrane and the connector, which are sufficient to affect the integrity of the seal and connection of the sealed welded connection. The inventors have found that it is advantageous to use a limiting collar to mechanically limit the hydrogenation expansion of the vanadium-based membrane at and near the welded connection. When hydrogen is introduced into the vanadium-based membrane, the hydrogenated vanadium-based membrane (tube) will expand within the limiting collar, and the expansion will be constrained by the limits of the inner surface of the limiting collar.

[0151] Figure 1 A first embodiment of a coupling and sealing device 100 of the present invention is illustrated. The device 100 comprises:

[0152] (1) A vanadium-based membrane 110, which preferably comprises a vanadium or vanadium alloy tube suitable for use as a hydrogen-selective membrane, such as taught in U.S. Patent No. 10,590,516, the contents of which should be understood to be incorporated into this specification by this reference. The vanadium-based membrane 110 has an outer diameter (D) about the longitudinal axis XX. As previously described, the outer diameter D is the outer diameter of the vanadium-based membrane when the vanadium-based membrane 110 is in an unhydrogenated state (i.e., not in a hydrogenated expanded state). The vanadium-based membrane 110 preferably comprises a thin-walled tube having an outer diameter between 2 and 25 mm and a wall thickness of 0.1 to 1 mm. However, it should be understood that other configurations as described above may also be used. Likewise, it should be understood that other metal membranes may be used, such as other Group 5 metals, such as tantalum or niobium metals or metal alloys.

[0153] (2) A connector 120 comprising a metal fluid connection fitting (preferably a metal gas connection fitting) formed of a metal or metal alloy different from the vanadium-based membrane 110, typically one of steel, stainless steel, nickel-chromium-iron alloy, brass, Inconel, incoloy, or a combination thereof. The connector 120 comprises a connector structure 122 configured to receive the end section 111 of the vanadium-based membrane 110 thereon. In the illustrated embodiment, the connector structure 122 comprises an inclined section in the form of a frustoconical section. However, it should be appreciated that other configurations are possible.

[0154] (3) A welded connection 130 located above a connection interface 132 between the end segment 111 of the vanadium-based membrane 110 and the connector structure 122, where the end segment 111 of the vanadium-based membrane 110 substantially abuts or overlaps an adjacent face of the connector structure 122. The welded connection 130 includes a continuous weld extending circumferentially around the connection interface 132 and above the connection interface 132. The welded connection 130 may be formed using any suitable welding technique, such as a laser welded connection, or an arc welded connection (e.g., TIG) or an electron beam weld. As noted in more detail below, it should be understood that other types of connections, such as threaded connections or O-ring sealed connections, may also be used.

[0155] (4) A restriction collar 140 configured to extend from at least the connection interface 132 and the weld connection 130 and to extend axially above the vanadium-based membrane 110 relative to the longitudinal axis XX. In the illustrated embodiment, the restriction collar extends above the connection interface 132 and the weld connection 130 and to extend axially above at least a portion of the vanadium-based membrane 110 and the connector 120 relative to the longitudinal axis XX. The restriction collar 140 illustrated comprises a substantially cylindrical tube. However, it should be appreciated that the restriction collar may have any suitable overall shape and configuration. The restriction collar is typically comprised of at least one of steel, stainless steel, nickel-chromium-iron alloy, brass, or a combination thereof.

[0156] like Figure 1 , Figure 2 and Figure 3 As shown, the restraining collar 140 has the following interconnected sections: (1) a restraining section 144; (2) an expansion section 146; and (3) a transition section 148 at the beginning of the expansion section 146. The restraining collar 140 is shown also includes a collar tightening section 149. Each of these sections will now be discussed in more detail:

[0157] The restraining section 144 is configured to move the expansion zone of the vanadium-based membrane 110 away from the weld connection 130, thereby reducing the strain on the weld connection 130 and allowing the seal of the weld connection 130 to remain intact during the expansion and contraction changes experienced during the hydrogenation changes of the membrane 110. It does this by providing mechanical constraints on the expansion of hydrogen metal (H / M) within this section. Figure 1 As best shown, the restriction section 144 is configured to extend axially above the vanadium-based membrane 110 from the connection interface 132 (and the welded connection 130 thereon) to a transition section 148, which is located at the beginning of the expansion section 146. Here, the inner surface 150 of the restriction collar 140 is adjacent to and more preferably spaced apart (e.g., substantially parallel spaced apart) from the outer surface 152 of the vanadium-based membrane 110. The inner surface of the restriction section 144 defines a restriction diameter C that is 0.95 times to 1.05 times the outer diameter D of the vanadium-based membrane 110. In embodiments such as the illustrated embodiment, the restriction diameter C is greater than D (C>D). For example, C can be 1.01D to 1.05D, such as 0.05 mm greater than the outer diameter D of the vanadium-based membrane 110. Here, when the vanadium-based membrane is in an unhydrogenated state, the restriction diameter C of the inner surface 150 of the restriction section 144 is spaced apart from the outer surface 152 of the vanadium-based membrane 110. This spacing provides a small gap to enable the vanadium-based membrane and the connector to be installed within the restriction collar. The restriction diameter is also preferably no greater than 0.12 mm of the outer diameter D of the vanadium-based membrane 110 to substantially restrict movement of the vanadium-based membrane 110 about the welded connection 130 between the vanadium-based membrane 110 and the connector 120 during changes in expansion and contraction experienced during changes in membrane hydrogenation. It should be understood that in some embodiments, the restriction diameter C in the restriction section can be substantially the same as D, resulting in an interference fit between the overlapping portion of the restriction section 144 of the restriction collar 140 and the vanadium-based membrane 110.

[0158] The inner surface 150 of the restraining collar 140 is also preferably spaced apart, typically substantially parallel, from the outer surface 152 of the connector 120 on the other side of the weld connection, and the collar also extends over the weld connection 130 and the connection interface 123 therein. Thus, this restraining portion 143 of the restraining collar 140 can mechanically constrain any expansion of the weld connection 130 during hydrogenation expansion and cycling.

[0159] It should be understood that while the dimensions discussed below are expressed in terms of the outer diameter D of the vanadium-based membrane 110 , these dimensions may also be expressed in terms of the confinement diameter C. As described above, according to an embodiment, the inner surface of the confinement section defines a confinement diameter C that is 0.95 to 1.05 times the outer diameter D of the vanadium-based membrane 110 .

[0160] The length L1 of the restraining section 144 is selected to provide sufficient spacing between the connection interface 132 (and the weld connection 130 thereon) and the expansion section 146. Figure 1 In the illustrated embodiment, the confinement section 144 extends from the bonding interface 132 to the transition section 148 over the vanadium-based film 110 by at least 0.25D, and preferably from 0.25D to 2D.

[0161] The expansion section 146 uses a slope or curve to control the expansion of the vanadium hydride-based membrane 110 so that the vanadium-based membrane 110 gradually expands to its natural diameter as the vanadium-based membrane 110 extends away from the weld connection along the longitudinal axis XX. In the expansion section 146, the diameter of the restraining collar 100 expands from the restraining diameter C to the expanded diameter D2. This gradual expansion is controlled by the configuration of the expansion section 146, which, in the embodiment shown, has a Figures 1 to 3 The inclined or tapered inner diameter 154 in the expansion section 146 gradually increases in diameter from the restricted diameter C to the expanded diameter D2 at the distal end 147 of the expansion section 146. In the illustrated embodiment, the change from the restricted diameter C to the expanded diameter D2 includes a transition section 148 (described in more detail below) and an angled section 145, the angled section including an inclined surface having an expansion angle α relative to the longitudinal axis, the expansion angle including a non-zero angle less than 17.5 degrees (i.e., an angle greater than zero to 17.5 degrees, such as from 0.5 to 17.5 degrees, preferably from 0.5 to 6 degrees). In the illustrated embodiment, the inclined surface is about 5 degrees. The expanded diameter D2 is selected to be greater than the maximum diameter of the vanadium-based membrane after hydrogenation. As previously described, the vanadium-based hydrogen-selective membrane tube can linearly expand by up to 5% in one dimension / axis (such as diameter) when hydrogenated at conventional operating temperatures / pressures compared to ambient conditions without hydrogen. Therefore, the expanded diameter D2 is at least 1.01D, preferably at least 1.02D. However, where the expansion is expected to be greater than the maximum linear expansion, the expanded diameter D2 may be at least 1.05 D. The length of the expansion section L2 will then be determined by the expansion angle α and the size of the expanded diameter D2 that the ramp / taper must achieve.

[0162] As mentioned above, it should be understood that the expanded diameter D2 ( Figure 1 ) will also be larger than the limiting diameter C of the limiting section 144 of the limiting collar 140. Similarly, the maximum diameter of the hydrogen separation membrane 110 after hydrogenation, i.e., the diameter D MH (not shown), is larger than the restriction diameter C of the restriction section 144 of the restriction collar 140, and the outer diameter D of the metal hydrogen separation membrane 110 when the metal hydrogen separation membrane 110 is in an unhydrogenated state - this can be understood by the nature of the hydrogenation process.

[0163] The transition section 148 is located at the beginning of the expansion section 146 and forms a curved transition surface between the restriction section 144 and the angled section 145 of the expansion section 146. As shown, the transition section 148 includes a curved surface 119 with a radius R of at least 0.1D, typically 0.1D to 10D. Therefore, the transition section 148 provides a curved surface that is configured to prevent the formation of stress concentration points when the inner surface of the restriction collar 140 transitions from the restriction diameter C to the tapered surface of the expansion section. In this regard, when hydrogen is introduced into the vanadium-based membrane, the hydrogenated vanadium-based membrane (tube) will expand within the restriction collar 140, and the expansion will be constrained by the confines of the inner surface of the restriction collar 140. In the restriction section 144, the outer surface 152 of the vanadium-based membrane 110 will abut the inner surface 150 of the section. Similarly, the outer surface 152 of the vanadium-based membrane 110 will abut the inner surface 150 of the expansion section 146 until reaching the point of the natural hydrogen-expanded diameter of the vanadium-based membrane 110. At the transition section 148, the outer surface 152 of the hydrogenated vanadium-based membrane 110 will follow the shape / curve of the transition section 148 to expand from the restricted diameter C to the tapered surface 154 of the expansion section 146.

[0164] It should be understood that the length of the transition section 148 depends on the transition radius R and the average slope / angle of the angled section 145 of the expansion section 146. The length depends on the intersection tangent between the curve of the transition radius and the slope of the angled section 145. For the same transition radius R, the greater the expansion angle α, the greater the length of the transition section 148, as described below with respect to Fig.17 Explained.

[0165] The transition section 148 is located at the end of the restriction section 144 and at the beginning of the expansion section 146 and transitions from the surface of the restriction section 144 to the tapered surface 154 of the angled section 145 of the expansion section 146. In one embodiment, as Figure 2 The illustrated expansion angle α includes the curve provided by the transition section 148 (and includes the transition radius R). In alternative embodiments, the tapered surface 154 may not have a linear slope, but may include a curved surface, or include multiple curves or slopes. For example, Figure 2A An embodiment of a restraining collar 140A is illustrated in which the angled section 145A (here a curved section) and the transition section 148A include a continuously curved surface 154A. In this embodiment, the transition section 148A and the angled (curved) section 145A of the expansion section 146A follow the same or similar curve and may share a common radius. Nevertheless, it should be understood that in other embodiments, the transition section 148A may be located on a different curve than the angled (curved) section 145 following the transition section 148A. It should also be understood that Figure 2A About Figure 1 and Figure 2 Features similar to those shown and described have the same reference numerals, and the description of these features applies equally to this embodiment. In embodiments where at least the expansion section is located on at least one curve, the expansion angle α (in Figure 2A The average expansion angle (shown as α2) includes the curve and is generally a non-zero angle less than 17.5 degrees, such as between 0.5 and 17.5 degrees, preferably from 0.5 to 6 degrees. Nevertheless, the expansion section 146A and the tapered / curved / inclined surface 154A provide the same functionality as described above, in that it will still provide an average step-wise increase in diameter from the limiting diameter C to the expanded diameter D2 at the distal end 147 of the expansion section 146. In these embodiments, the average expansion angle may also include the curved section provided by the transition section 148.

[0166] like Figure 1 As shown, the restriction collar 140 also includes a collar fastening section 149 extending above the connection interface 132 and configured to be fastened to a section of the connector 120. Here, the connector 120 includes a fastening structure, which in the illustrated embodiment includes threads 160. However, a variety of other interengaging fastening structures can be used. The fastening section 149 includes a mating fastening structure, again threads 162, which is configured to interconnect the restriction collar fastening section 149 to the connector 120.

[0167] As described above, the vanadium-based membrane 110 includes a vanadium or vanadium alloy tube suitable for use as a hydrogen-selective membrane, such as taught in U.S. Patent No. 10,590,516. As taught in that specification, the vanadium-based membrane can be formed of vanadium or a vanadium alloy. Generally, a specific vanadium metal or alloy is selected based on the suitability of the vanadium metal or alloy for use in a membrane separation device. In some embodiments, the vanadium-based membrane includes a vanadium alloy, which includes: vanadium; aluminum in an amount greater than 0 to 10 at%; and Ta in an amount less than 0.01 at%, which has a ductility greater than 10% elongation, preferably greater than 11% elongation. The vanadium alloy may further include a grain refining element selected from Ti, Cr, Fe, Ni or B, in an amount greater than 0 to 5 at%, preferably between 0.2 and 4.5 at%. In some embodiments, the content of the grain refining element is from 0.1 to 2 at%, preferably from 0.1 to 2 at%, and more preferably from 0.1 to 1 at%. In some embodiments, the vanadium-based membrane is coated with a Pd-based coating or a Pd-Au-based coating. Again, it should be understood that although the hydrogen separation membrane shown includes a vanadium-based membrane 110, the membrane 110 can also be formed of other metal membrane materials, such as a Group 5 base metal or metal alloy, such as tantalum or niobium.

[0168] Figure 3AAn alternative (second) embodiment of the coupling and sealing device 100 of the present invention is provided. The device 100A includes a plurality of Figures 1 to 3 The same features as the first embodiment shown in FIG. Figures 1 to 3 It should be understood that the above description of the features in the first embodiment is also applicable to Figure 3A In this embodiment, the restriction collar 140A is configured without the restriction section 144 ( Figure 1 ). Similar to the first embodiment, the restraining collar 140A is configured to extend axially from the restraining end 144A of the expansion section 146, at least from the connection interface 132 and the weld connection 130, above the vanadium-based membrane 110 relative to the longitudinal axis XX. The restraining collar 140A also extends above the connection interface 132 and the weld connection 130, and extends axially above the vanadium-based membrane 110 and at least a portion of the connector 120 relative to the longitudinal axis XX. This second embodiment of the restraining collar 140A has the following interconnected sections: (1) an expansion section 146; (2) a transition section 148; and (3) a collar fastening section 149. Each of these sections will now be discussed in more detail:

[0169] Similar to the first embodiment, the expansion section 146 uses a slope or curve to control the expansion of the vanadium hydride-based membrane 110, so that the vanadium-based membrane 110 gradually expands to its natural diameter as the vanadium-based membrane 110 extends away from the weld connection along the longitudinal axis XX. Similarly, the expansion section includes a transition section 148 and an angled section 145. The diameter of the restriction collar 100 expands from the restricted diameter C at the restricted end 144A of the expansion section 146 to the expanded diameter D2 at the other end of the expansion section 146. Similar to the first embodiment, the angled section 145 of the expansion section 146 includes an inclined surface having an expansion angle α relative to the longitudinal axis, the expansion angle including a non-zero angle less than 17.5 degrees (i.e., an angle greater than zero to 17.5 degrees), such as an angle from 0.5 to 17.5 degrees, preferably from 0.5 to 6 degrees. Similarly, the expanded diameter D2 is at least 1.01D, preferably at least 1.02D. However, where expansion is expected to be greater than the maximum linear expansion, the expanded diameter D2 may be at least 1.05 D. The length L2 of the expansion section 146 will be determined by the expansion angle α and the size of the expanded diameter D2 that the taper must achieve.

[0170] The restraining end 144A is located at the beginning of the expansion section 146, near the connection interface 132, and is the area of ​​the restraining collar 140A where the inner surface 150 of the restraining collar 140 is adjacent to or spaced apart from the outer surface 152 of the vanadium-based membrane 110. The inner surface of the restraining end 144A defines a restraining diameter C that is 0.95 to 1.05 times the outer diameter D of the vanadium-based membrane 110.

[0171] In this embodiment, the transition section 148 extends from the restricted end / portion 144A into the expansion section 146 and includes a curved surface 119 having a radius R of at least 0.1D and typically 0.1D to 10D. The curved surface gradually increases the rate of expansion from the restricted diameter until the rate of expansion reaches a maximum at the angled section 145. The gradual increase in expansion provided by the curved surface 119 reduces strain at the weld connection 130.

[0172] The inner surface 150 of the restraining collar 140 may also be configured to extend over the weld connection 130 and the connection interface 132 - as shown in FIG. Figure 3A Thus, the restraining portion 143 of the restraining collar 140 can mechanically constrain any expansion of the welded connection 130 during hydrogenation expansion and cycling.

[0173] like Figure 3A As shown, the restriction collar 140 also includes a collar fastening section 149 extending above the connection interface 132 and configured to be fastened to a section of the connector 120. Here, the connector 120 includes a fastening structure, which in the illustrated embodiment includes threads 160. However, a variety of other interengaging fastening structures can be used. The fastening section 149 includes a mating fastening structure, again threads 162, which is configured to interconnect the restriction collar fastening section 149 to the connector 120.

[0174] although Figures 1 to 3A A welded connection 130 is illustrated above the connection interface 132 between the end segments 111 of the vanadium-based membrane 110, but it should be understood that other types of connections may be used in place of the welded connection 130, wherein the restriction collar 140 operates in an equivalent manner as described above. For example, the welded connection may alternatively include any suitable gas-tight connection between these bodies, such as (but not limited to) a welded connection, a brazed connection, a threaded connection, an O-ring sealed connection, etc.

[0175] Even if you use Figures 1 to 3A As shown in the restraining collar 140, it is still possible for leaks to develop at the weld connection 130, thereby resulting in a loss of the ability to maintain high purity hydrogen production. Figures 4 to 8A third embodiment of the present invention's joint and sealing devices 200A and 200B is taught which is designed with further sealing features to prevent weld failure and / or defects that may affect the weld upon hydriding and resulting expansion of the vanadium-based membrane 210 .

[0176] In this embodiment, the restraining collars 240A and 240B can be configured to provide both mechanical restraint and have sections that provide backup for seal integrity to reduce reliance on the weld alone to achieve seal integrity. This helps isolate the weld connection 230 from changes in external process conditions. The secondary seal is designed to isolate the weld connection 230 and can provide an additional sealing backup layer / buffer in the event of weld failure during cycling or other operational changes.

[0177] like Figures 4 to 8 As shown, the restraining collars 240A and 240B have two different configurations that are designed for the specific end of the vanadium-based membrane 210 to which the restraining collars 240A and 240B are designed to fit.

[0178] Thus, each vanadium-based film 210 will include:

[0179] 1. A flow end connector collar 240A, which includes a tubular sealing extension end 270 designed to connect to the flow / flange end of the vanadium-based membrane 210; and

[0180] 2. A blind plug collar 240B, which forms an end cap on the blind end of the vanadium-based membrane 210.

[0181] It should be understood that both the flow end connector collar 240A and the blind plug collar 240B include the following features that are the same as the first embodiment. It should be understood that similar features to the first embodiment are provided with the same reference numerals plus 100, and the description above for those features of the first embodiment is equally applicable. Figures 4 to 8 These characteristics are:

[0182] (1) A vanadium-based membrane 210 comprising a vanadium or vanadium alloy tube suitable for use as a hydrogen-selective membrane. The vanadium-based membrane 210 has an outer diameter (D) about a longitudinal axis XX.

[0183] (2) A connector 220 comprising a metal fluid connection fitting (preferably a metal gas connection fitting) formed of a metal or metal alloy different from the vanadium-based membrane 210, typically one of steel, stainless steel, nickel-chromium-iron alloy, brass, Inconel alloy, Incoloy alloy, or a combination thereof. The connector 220 comprises a connector structure 222 configured to receive the end segment 111 of the vanadium-based membrane 110 thereon. In the illustrated embodiment, the connector structure 222 comprises an inclined segment in the form of a truncated conical segment. However, it should be recognized that other configurations are possible. As explained in more detail below, the exact configuration of the connector 220 for the flow end connector collar 240A and the blind plug collar 240B is customized for the function of the respective end (flow end or blind end) of the vanadium-based membrane 210.

[0184] (3) A welded connection 230 located above a connection interface 232 between the end segment 211 of the vanadium-based membrane 210 and the connector structure 222, where the end segment 211 of the vanadium-based membrane 210 substantially abuts or overlaps an adjacent face of the connector structure 222. The welded connection 230 includes a continuous weld extending circumferentially around and above the connection interface 232.

[0185] (4) A restriction collar 240A, 240B configured to extend from at least the connection interface 132 and the weld connection 130 and to extend axially above the vanadium-based membrane 110 relative to the longitudinal axis XX. The restriction collar 140 shown comprises a substantially cylindrical tube. However, it should be appreciated that the restriction collars 240A, 240B may have any suitable overall shape and construction. The restriction collars 240A, 240B are typically comprised of at least one of the following: steel, stainless steel, nickel-chromium-iron alloy, brass, or a combination thereof. Each of the flow end connector collar 240A embodiment and the blind plug collar 240B embodiment has interconnected sections: (A) a restriction section 244; (B) an expansion section 246; and (C) a transition section 248, as described above for the first embodiment, the details of which are equally applicable to this second embodiment. The difference in construction from the first embodiment is the construction of the restriction collar fastening section 249.

[0186] exist Figures 4 to 620A. A flow end connector collar 240A is illustrated in FIG. 20A. In this embodiment, the connector 220 includes a flow connection fitting including a connection structure 222 at one end as described above; and a tubular extension section 223 extending longitudinally away from the connection interface to a distal end 225. The tubular extension 223 includes a threaded connector 260 proximate the end of the connection structure 222 and designed to threadably engage with a connection section 251 of a collar fastening section 249 of the flow end connector collar 240A. Here, the restricting collar fastening section 249 extends above the connection interface 232 to a first connection section 251. The fastening section 249 has a mating fastening structure, again threads 262, which is configured to interconnect the restricting collar fastening section 249 to the connector 220. The restricting collar fastening section 249 also includes a threaded sealing end 265 that is configured to seal and interconnect to a compression fitting 272 (e.g., a compression fitting such as a Hy-Lok type compression fitting or a Swagelok type connector) and to seal between the tubular extension 223 using a ferrule 274 (preferably a graphite ferrule). The illustrated compression fitting 272 includes a sealing nut that is configured to be threadedly fastened to the distal fastening end of the sealing section. However, any suitable compression fitting and mating fastening device may be used to assemble the compression fitting 272 onto the sealing end 265 of the flow end connector collar 240A. The compression fitting 272 and ferrule 274 are screwed onto the sealing end 265 of the flow end connector collar 240A to create a fluid seal between the compression fitting 272 and ferrule 274 and a portion of the tubular extension 223. The ferrule 274 may have any suitable configuration. Thus, as Figure 4 As shown, the secondary seal around the weld connection 230 includes:

[0187] (1) Upstream of the weld connection 230: sealing the vanadium-based tube 210 to the confinement collar 240A in a portion of the confinement section 244 and the expansion section 246 as the vanadium-based tube 210 expands upon hydriding to be mechanically constrained in those sections 244, 246; and

[0188] (2) Downstream of weld connection 230 : the seal between compression fitting 272 and ferrule 274 and a portion of tubular extension 223 .

[0189] exist Figure 7 and Figure 82. The blind plug collar 240B is illustrated in FIG. 2. In this embodiment, the connector 220 includes a blind plug / end cap fitting that includes a connection structure 222 at one end as described above and a blind end 223A. The blind end 223A includes a solid section having a threaded connector 260A that is designed to threadably engage with a connection section 251A of a collar fastening section 249A of the blind plug collar 240AB. Here, the limiting collar fastening section 249A extends above the connection interface 232 to the first connection section 251A. The fastening section 249A has a mating fastening structure, again threads 262A, that is configured to interconnect the limiting collar fastening section 249A to the connector 220. The restriction collar fastening section 249 also includes a capping end 266, which includes a sealing blind cap attached to and extending from the fastening section 249A and configured to completely seal the blind end 223A of the connector 260A within the restriction collar 240B. This configuration ensures that there are no leak points on the capping end side of the vanadium-based membrane 210.

[0190] Figures 1 to 3 The illustrated coupling and sealing device 100 may be formed by the following method:

[0191] Step 1: Preparation of vanadium-based membrane:

[0192] A suitable vanadium-based membrane tube 110 is cut to a suitable length, and then each end is trimmed to a right angle to form an end face 311 suitable for the end section 111 of the vanadium-based membrane 110, which overlaps the adjacent face of the connector structure 122 of the connector 120. This is achieved by clamping the vanadium-based membrane tube 110 in a fixture 300, which holds the tube perpendicular to the working surface 302 of a flat grinding disk 304 (or other equivalent grinding device). The fixture 300 is then held on the flat grinding disk 304 and the end face 311 is ground until the end face 311 of the tube 110 is at a right angle.

[0193] Step 2: Solder to create the joint / connection:

[0194] like Figure 1 As shown, the end section 111 of the vanadium-based membrane tube 110 is mounted on the sloped surface of the connector structure 122 of the connector 120, wherein the vanadium-based membrane tube 110 and the connector structure 120 are in contact at the connection interface 132. The connection interface 132 is then welded, such as by laser welding, preferably autogenous welding (without adding filler wire), to form the welded connection 130. In some embodiments, the welding is completed in two steps. Fig.101 illustrates a cross section of a completed welded connection 130. In this figure, dashed line 310 represents the original shape of the vanadium-based membrane before welding, and dashed line 312 represents the original shape of the stainless steel connector. Since the surface of the welded connection 130 is flush or slightly lower than the surface of the vanadium-based membrane and the stainless steel connector, a close-fitting restraining collar 140 can slide over the welded connection.

[0195] Step 3: Assemble the restraining collar:

[0196] Finally, as about Figures 1 to 3 As shown and described, the restraining collar 140 is assembled over the vanadium-based membrane tube 110 and the weld connection 130 to extend from the connection interface and axially extend over the vanadium-based membrane tube 110 relative to the longitudinal axis XX. Figure 1 As shown, the restraining collar 140 is positioned over the weld connection 130 and is retained on the connector structure 122 using a threaded connector 162 in the connector section 149 .

[0197] After hydriding, the vanadium-based membrane 110 expands and the restraining collar 140 constrains the vanadium-based membrane 110 in the restraining section 144 adjacent the weld connection 130. The tapering of the expansion section 146 provides for gradual expansion to the final unconstrained size of the vanadium-based membrane 110 as it hydrids.

[0198] It should be understood that a similar method may also be used to form the coupling and sealing devices 200A and 200B according to the third embodiment of the present invention.

[0199] It should also be understood that the tubular membrane using the coupling and sealing device of the present invention can be incorporated into a tubular catalytic membrane reactor (CMR), such as taught in U.S. Pat. No. 10,590,516, which is also understood to be incorporated into this specification by reference. As described in U.S. Pat. No. 10,590,516, a CMR incorporating a tubular membrane can be used to selectively extract hydrogen from a hydrogen-containing gas (such as synthesis gas) to produce a raffinate (H 2 Depleted syngas) and H 2 Permeate.

[0200] Example

[0201] Example 1 - Stress Analysis

[0202] Figures 1 to 3The illustrated coupling and sealing arrangement 100 was drawn in SolidWorks (Solidworks Simulation Professional (SSP) software package (Version 2021 Service Pack 5.1, available from Dassault Systems SolidWorks Corporation, Waltham, Massachusetts, USA)) and a stress analysis was performed taking into account the temperature and hydride-induced expansion of the vanadium-based membrane during typical operating pressures / temperatures.

[0203] The axial stress and hoop stress at the outer surface of the connection weld are only based on the above SolidWorks model output.

[0204] Fig.11 , when the vanadium-based film 110 expands due to hydrogenation, the stress analysis results of the radial displacement of the limiting collar 140, the connector 120 and the vanadium-based film 110 are illustrated. Fig.11 In the figure, radial displacements are marked with colors, with red indicating larger displacements than blue. Fig.11 As shown, the confinement collar 140 substantially constrains the vanadium-based membrane 110 from significant expansion in the confinement section 144, with the majority of radial displacement occurring in the expansion section 146 and transition radius section 148. The modeling results (transitioning from light blue to orange / red) show that the taper acts as a means of gradually allowing expansion from a constrained state in section 144 to a fully naturally expanded size in section 146.

[0205] Example 2 - Simulation of stresses in a membrane and weld joint under hydride expansion

[0206] background

[0207] When the vanadium component of the membrane undergoes a hydriding process (absorption of hydrogen, also known as hydriding), the metal undergoes a significant expansion relative to the amount of hydrogen contained in the lattice. The components of different materials in the membrane mounting / sealing device (stainless steel, vanadium-stainless steel alloy welds) do not experience this expansion because they do not experience the same magnitude of hydrogen absorption, if any. Therefore, significant stresses are induced at their interface with the membrane during operation due to the mismatch in expansion rates. Failures of welds and membranes under various conditions in the past have been attributed to such stresses.

[0208] Stress simulation method

[0209] Several challenges hampered the opportunity to conduct physical material testing and measurements during operation, so to understand the stresses at critical locations, a finite element analysis (FEA) study was performed using the Solidworks Simulation Professional (SSP) software package (version 2021 Service Pack 5.1, available from Dassault Systems SolidWorks Corporation, Waltham, MA, USA). Notably, SSP does not natively support the hydride lattice expansion phenomenon, so a custom approach was required to simulate this expansion.

[0210] The simulation of materials under thermal expansion is a core capability of SSP, enabling the modeling of the expected effects under hydride expansion, such as:

[0211] Isotropic expansion is proportional to temperature (hydrogen content)

[0212] Internal stress distribution depends on temperature gradient (hydrogen content gradient)

[0213] Contact behavior between materials with different thermal expansion coefficients (hydride expansion coefficients)

[0214] The mechanical properties of metals change significantly at elevated temperatures, so a combined thermal + hydride expansion analysis method was used to gain insight into the failure mechanisms that may occur under the operating conditions (temperature and hydrogen under pressure). A nominal steady-state temperature of 325°C was chosen, and the material properties were adjusted to reflect the expected reduction in tensile strength.

[0215] Experimental data on the properties of vanadium hydrides were obtained by synchrotron analysis of vanadium hydrides, using in situ (non-ambient) synchrotron X-ray powder diffraction to i) measure hydrogen-induced lattice expansion, and ii) hydride formation in vanadium-based alloys. Data were obtained for vanadium hydride formation at different temperatures and different hydrogen partial pressures and used to estimate the unit cell volume for each condition, thereby inferring the hydrogen-induced lattice expansion / volume expansion. This experimental data matches the expected maximum practical hydrogen uptake level, where the H / M or hydrogen to metal ratio is ~0.65. Notably, the ratio of hydrogen to metal atoms (H / M) in vanadium-based films can be obtained from experimental data obtained at different temperatures and hydrogen partial pressures using a Hiden Isochema Sieverts rig. The modeling shows that for V-based films (hydrogen to metal ratio (H / M) of ~0.65, temperature of 300 to 400°C, H 2 Partial pressure up to 15 bara), at the expected maximum practical hydration:

[0216] The maximum volume expansion of the V-film is approximately +15%; and

[0217] ·V- Maximum linear expansion of the membrane (E h ) is approximately +5%.

[0218] In both cases, the extent of expansion varies depending on the amount of H-absorption (ie, the absorbed hydrogen to metal or H / M ratio).

[0219] In order to incorporate this value into the expansion analysis, a specific temperature-dependent coefficient for the expansion of vanadium hydrides (α h ):

[0220]

[0221] Combined with the known thermal expansion coefficient for vanadium The combined expansion coefficient α is obtained r :

[0222] α r =α t +α h

[0223] α r =8*10 -6 +1.67*10 -4

[0224]

[0225] Upon completion, the deformed geometry of the unconstrained membrane segment for the 325°C steady state simulation was checked relative to the expected total expansion (thermal and hydride) and confirmed to be -5.24%.

[0226] Detailed model outputs of stress components developed in critical sections of the membrane / fitting assembly were examined and used to inform the design of welding parameters and stress relief rings, with an emphasis on reducing stress concentrations and minimizing strain at the weld.

[0227] Hoop stress and axial stress were obtained via standard output from the SolidWorks modeling software package (Version 2021 Service Pack 5.1, available from Dassault Systems SolidWorks Corporation, Waltham, Massachusetts, USA).

[0228] result

[0229] Figure 12 to Figure 14 (B) provides the Solidworks modeling results of the hydride lattice expansion as well as the hoop stress and axial stress.

[0230] Fig.12Modeled stress components on the membrane and weld are illustrated, including axial and hoop stresses exerted on the vanadium-based membrane 110 and weld connection 130, where: tension (positive); and compression (negative).

[0231] Fig.13 The modeling results are illustrated, showing that when the vanadium-based film 110 is hydrogenated, for Figures 1 to 3 The connection and sealing device 100 shown in FIG. 1 shows a graph showing the relationship between the axial stress of the inner surface of the vanadium film at the connection interface and the distance from the welded connection (A); and a graph showing the relationship between the hoop stress of the inner surface of the vanadium-based film 110 at the connection interface and the distance from the welded connection (B). The unhydrogenated outer diameter of the vanadium-based film 110 is 9.54 mm.

[0232] like Fig.13 (A) and Fig.13 As shown in (B), if the inner diameter of the restraining collar is too large (loose fit - 9.75 ID), we see large compressive axial stresses and high tensile stresses at the V-based membrane-fitting interface (welded connection). It was found that collars > 9.75 mm continued to fail, while once the V-based membrane was hydrogenated (i.e., hydrogen permeation began), the first of the three membranes with a 9.65 mm collar remained strong after at least 1000 hours of operation.

[0233] like Fig.14 (A) and Fig.14 As shown in (B), a smaller transition radius R will cause the axial stress to be concentrated at this point and result in a significant increase in the maximum stress on the inner and outer surfaces of the vanadium-based film 110. Therefore, the transition radius specification is currently specified as 10 mm, which is approximately 1 times the outer diameter of the vanadium-based film 110. However, increasing it to about 1.5 times the outer diameter of the vanadium-based film 110 (i.e., 15 mm) or more may help to further reduce the stress concentration distribution.

[0234] Example 3 - Simulation of stress expansion sections with different expansion angles

[0235] Modeling was performed using the Solidworks Simulation Professional (SSP) software package (version 2021 Service Pack 5.1, available from Dassault Systems SolidWorks Corporation, Waltham, Massachusetts, USA) to determine the effects of different mean expansion angles on the Figure 1 Longitudinal bending stresses in the expanded section of the collar are shown. Modelling was performed for a 5 mm transition radius (ie ~0.5D). Fig.15 and Fig.16 Stress modeling results for the longitudinal bending stress at the outer surface of the membrane at average expansion angles of 0.5, 1, 3, 5, 6, 10, and 17.5 degrees are provided. Fig.15 Modeling the stresses from the end of the transition section, Fig.16 The stresses from the beginning of the transition section are modeled. It is worth noting that Fig.15 In the lines shown in , the 10 degree and 17.5 degree lines completely overlap, and in Fig.16 In addition to the valley value after 0mm, there is also overlap.

[0236] like Fig.15 and Fig.16 As shown, the general rule seems to be that the smaller the angle of the angled section 145, the better the longitudinal stress results. However, this stress advantage needs to be balanced with the practical requirements of material waste. At very small angles, such as less than 0.5 degrees, there will be a lot of waste material, covering a lot of film.

[0237] There are two stress peaks for each average expansion angle, such as Fig.15 Best Shown:

[0238] • The first peak, at the "entry point" at the beginning of the tapered section (at the point where the transition section of the expansion section intersects the angled section).

[0239] • A second peak, at the "breakaway point" where the membrane loses contact with the collar.

[0240] like Fig.15 and Fig.16 As shown, the peaks are well spaced for small angles of the angled section 145. As the angle increases, the peaks tend to bunch together and add up, forming undesirably high peak stresses.

[0241] Example 4 - Ring Inner Radius Expansion Rate

[0242] based on Figure 1 The expansion segment shown, the expansion rate (mm / mm) of the expansion segment of the collar is modeled for the distance (mm) from the start of the transition radius for a transition segment with a radius of 5 mm and an angled segment 145 with expansion angles of 1, 3, 5, 6, 10, and 17.5, respectively. The expansion rate increases along the transition segment 148 from the restricted end until the expansion rate reaches a maximum at the start of the angled segment 145. The angled segment 148 has a constant expansion rate (which is a constant slope) that is the maximum expansion rate of the expansion segment 146.

[0243] Fig.17 The results are illustrated in . As shown, the greater the expansion angle (greater expansion rate) of the angled section 145, the longer the transition section 148 is required. The length depends on the intersection tangent between the curve of the transition radius and the slope of the angled section of the expansion section, so the greater the expansion angle, the greater the length.

[0244] Fig.17 The radial expansion rate (mm / mm) of the different angled segments 145 modeled in Fig.17 The expansion rate of the transition section 148 increases to a maximum expansion rate that is located along the expansion section 146 at the point where the transition section 148 intersects the angled section 145 .

[0245] The above discussion applies to the radial expansion rate (in mm / mm) of the expansion section, but it also applies to the expansion angle of the expansion section 146. The expansion angle of the transition section 148 increases to a maximum expansion angle, which is located along the expansion section 146 at the point where the transition section 148 intersects the angled section 145. The expansion angle of the angled section 145 can be considered to be the maximum expansion angle of the expansion section 146.

[0246] When the terms "comprises" or "includes" are used in this specification (including the claims), they should be interpreted as specifying the presence of stated features, integers, steps or components, but not excluding the presence of one or more other features, integers, steps, components or groups thereof.

Claims

1. A coupling and sealing device for coupling and sealing a hydrogen separation membrane to a metal connector, the coupling and sealing device comprising: a metal hydrogen separation membrane mounted on or against a connector structure of the connector about a longitudinal axis, the connector being formed of a metal different from the hydrogen separation membrane, the hydrogen separation membrane having an outer diameter (D) about the longitudinal axis, the hydrogen separation membrane and the connector structure being in contact at a connection interface in which an end face of the hydrogen separation membrane is proximate to, substantially abuts against, or overlaps an adjacent face of the connector structure; a connecting portion connecting the hydrogen separation membrane and the connector structure around the connecting interface; as well as a confinement collar configured to extend from at least the connection interface and to extend axially above the hydrogen separation membrane relative to the longitudinal axis, the confinement collar comprising: an expansion section configured to extend axially from a restricted end to an expanded diameter above the hydrogen separation membrane relative to the longitudinal axis, the restricted end configured to extend around the hydrogen separation membrane relative to the longitudinal axis at or near the connection interface and having an inner surface defining a restricted diameter (C) configured to extend around an outer surface of the hydrogen separation membrane, wherein the expansion section comprises a transition section extending from the limiting end and comprising a curved surface having a transition radius of at least 0.1D; And wherein the expansion section comprises an angled or curved section in which the diameter of the restraining collar expands from the restraining diameter C to an expanded diameter comprising at least 1.01D.

2. The coupling and sealing device according to claim 1, wherein: The diameter of the restricting collar expands from the restricted diameter C to the expanded diameter restricted end at an average expansion angle relative to the longitudinal axis, the average expansion angle comprising a non-zero angle of less than 17.5 degrees.

3. A coupling and sealing device according to claim 1 or 2, wherein: The restricted end includes a restricted section configured to extend axially from the connection end to the expansion section above the hydrogen separation membrane relative to the longitudinal axis, the restricted section having an inner surface extending around the longitudinal axis at the restricted diameter, The transition section extends from a transition between the limiting section and the expansion section.

4. The coupling and sealing device according to claim 3, wherein: The inner surface of the confinement section is configured to be spaced apart from, preferably substantially parallel to, the outer surface of the hydrogen separation membrane.

5. A coupling and sealing device according to any one of the preceding claims, wherein: The hydrogen separation membrane has an outer diameter D, and the limiting diameter C is comprised between 0.95D and 1.05D, preferably between 0.99D and 1.05D, and more preferably between 1D and 1.05D.

6. A coupling and sealing device according to any one of the preceding claims, wherein: The confinement section is configured to extend from the connection interface to the transition section over the hydrogen separation membrane by at least 0.25D, preferably 0.25D to 2D, more preferably 0.25D to 1.5D, more preferably 0.25D to 1D.

7. A coupling and sealing device according to any one of the preceding claims, wherein: The expanded diameter is at least 1.02D, preferably at least 1.05D, more preferably at least 1.1D.

8. A coupling and sealing device according to any one of the preceding claims when dependent on claim 2, wherein: The average expansion angle is from 0.5 to 6 degrees, preferably from 3 to 5 degrees.

9. A coupling and sealing device according to any one of the preceding claims, wherein: The transition radius ranges from 0.1D to 10D, preferably from 0.5D to 5D, and more preferably from 1D to 5D.

10. A coupling and sealing device according to any one of the preceding claims, wherein: The expansion section extends at least 0.2D relative to the longitudinal axis.

11. The coupling and sealing device according to claim 10, wherein: The expansion section extends at least 0.3D, preferably at least 0.4D, more preferably at least 0.5D relative to the longitudinal axis.

12. A coupling and sealing device according to any one of the preceding claims, wherein: The outer diameter (D) of the hydrogen separation membrane is between 2 and 25 mm, preferably between 5 and 20 mm, and the wall thickness is from 0.05 to 1 mm, preferably from 0.1 to 1 mm.

13. A coupling and sealing device according to any one of the preceding claims, wherein: The confinement collar is configured to extend above the connection interface of the hydrogen separation membrane to a collar fastening section configured to be fastened to a section of the connector, the collar fastening section including a fastening structure configured to interconnect the confinement collar to a mating fastening structure of the connector.

14. The coupling and sealing device according to claim 13, wherein: The fastening structure includes a threaded connection configured to matingly fasten to threads located on the connector.

15. A coupling and sealing device according to any one of the preceding claims, wherein: The restraining collar also includes an end cap configured to form an end seal around the connector.

16. A coupling and sealing device according to any one of the preceding claims, wherein: The connector includes a tubular extension extending longitudinally away from the connection interface, and The restraining collar includes a sealing section configured to extend over the tubular extension of the connector to a distal fastening end, Wherein, the limiting collar also includes a compression fitting, which is configured to be fastened to the distal fastening end of the sealing section, and the compression fitting includes at least one collar, which is configured to seal around the segment of the tubular extension of the connector when the compression fitting is fastened to the distal fastening end of the sealing section.

17. A coupling and sealing device according to claim 16, wherein: The at least one ferrule includes a graphite ferrule.

18. A coupling and sealing device according to claim 16 or 17, wherein: The compression fitting includes a sealing nut configured to be threadably fastened to the distal fastening end of the sealing segment.

19. A coupling and sealing device according to any one of claims 16 to 18, wherein: The sealing segment includes a fastening structure configured to interconnect the restraining collar to a mating fastening structure of the connector.

20. A coupling and sealing device according to any one of the preceding claims, wherein: The restraining collar is composed of at least one of aluminum, an aluminum alloy, steel, stainless steel, nickel-chromium-iron alloy, brass, or a combination thereof.

21. A coupling and sealing device according to any one of the preceding claims, wherein: The connector is comprised of at least one of steel, stainless steel, Inconel, brass, Inconel, Incoloy, or a combination thereof.

22. A coupling and sealing device according to any one of the preceding claims, wherein: The hydrogen separation membrane comprises a Group V metal or metal alloy, preferably a vanadium, tantalum or niobium metal or metal alloy, more preferably vanadium or a vanadium alloy.

23. A coupling and sealing device according to claim 22, wherein: The hydrogen separation membrane comprises a vanadium alloy, the vanadium alloy comprising: vanadium; aluminum in an amount greater than 0 to 10 at %; and Ta in an amount less than 0.01 at %, the vanadium alloy having a ductility greater than 10% elongation, preferably greater than 11% elongation.

24. A coupling and sealing device according to any one of the preceding claims, wherein: The hydrogen separation membrane is coated with a Pd-based coating or a Pd—Au-based coating.

25. A coupling and sealing device according to any one of the preceding claims, wherein: The hydrogen separation membrane is tubular.

26. A coupling and sealing device according to any one of the preceding claims, wherein: The hydrogen separation membrane has an outer diameter (D) between 2 and 25 mm, preferably between 5 and 20 mm, and a wall thickness from 0.05 to 1 mm, preferably from 0.1 to 1 mm, more preferably from 0.2 to 0.8 mm, and more preferably from 0.2 to 0.5 mm.

27. A coupling and sealing device according to any one of the preceding claims, wherein: The connector is tubular.

28. A coupling and sealing device according to any one of the preceding claims, wherein: The wall thickness of the connector is from 1 to 5 mm, preferably from 1 to 3 mm, more preferably from 1 to 2 mm.

29. A coupling and sealing device according to any one of the preceding claims, wherein: The connector structure includes an inclined or chamfered section configured to receive an end section of the hydrogen separation membrane thereon.

30. A coupling and sealing device according to any one of the preceding claims, wherein: The connection comprises a welded connection.

31. A coupling and sealing device according to claim 30, wherein: The welded connection includes a continuous weld extending circumferentially around and over the connection interface.

32. A coupling and sealing device according to claim 30 or 31, wherein: The welded connection includes a laser welded connection, an electron beam welded connection or an arc welded connection.

33. A method of bonding and sealing a hydrogen separation membrane to a metal connector, the method comprising: mounting an end segment of a metal hydrogen separation membrane on or against a connector structure of a connector, the connector being formed of a metal different from the hydrogen separation membrane, the hydrogen separation membrane having an outer diameter (D) about the longitudinal axis, the hydrogen separation membrane and the connector structure being in contact at a connection interface in which an end face of the hydrogen separation membrane is proximate, substantially abuts or overlaps an adjacent face of the connector structure; coupling the hydrogen separation membrane to the connector structure to couple and seal the hydrogen separation membrane to the connector through the connection interface; and positioning a confinement collar over the hydrogen separation membrane to extend at least from the connection interface and axially over the hydrogen separation membrane relative to the longitudinal axis, wherein the restriction collar comprises: an expansion section, the expansion section being configured to extend axially from a restriction end to an expanded diameter above the hydrogen separation membrane relative to the longitudinal axis, the restriction end being configured to extend around the hydrogen separation membrane at or near the connection interface relative to the longitudinal axis and having an inner surface defining a restriction diameter (C), the inner surface being configured to extend around an outer surface of the hydrogen separation membrane; the expansion section comprising a transition section extending from the restriction end and comprising a curved surface having a transition radius of at least 0.1D; And wherein the expansion section comprises an angled or curved section in which the diameter of the restraining collar expands from the restraining diameter C to an expanded diameter comprising at least 1.01D.

34. A method according to claim 33 using a coupling and sealing device according to any one of claims 1 to 32.

35. The method according to claim 33 or 34, wherein: The connector includes a tubular extension extending longitudinally away from the connection interface, and the restricting collar includes a sealing section configured to extend over the tubular extension of the connector to a distal fastening end, and The method further comprises: A compression fitting is fastened to the distal fastening end of the sealing segment, the compression fitting including at least one ferrule that seals around a segment of the tubular extension of the connector when the compression fitting is fastened to the distal fastening end of the sealing segment.

36. The method of claim 35, wherein: The at least one ferrule includes a graphite ferrule.

37. A method according to any one of claims 33 to 36, wherein: The compression fitting includes a sealing nut configured to be threadably fastened to the distal fastening end of the sealing segment.

38. A method according to any one of claims 33 to 37, wherein: The connector is comprised of at least one of steel, stainless steel, Inconel, brass, Inconel, Incoloy, or a combination thereof.

39. The method according to any one of claims 33 to 38, wherein: The hydrogen separation membrane is tubular, and the connector is tubular.

40. The method according to any one of claims 33 to 39, wherein: The hydrogen separation membrane is welded to the connector through the connection interface.

41. The method of claim 40, wherein: The weld includes a continuous weld extending circumferentially around and over the joining interface.

42. The method according to claim 40 or 41, wherein: The welding includes laser welding connection, electron beam welding connection or arc welding connection.

43. A hydrogen separation membrane system comprising a hydrogen separation membrane coupled and sealed to a connector structure using the coupling and sealing device according to any one of claims 1 to 32.

44. A hydrogen separation membrane confinement collar, the hydrogen separation membrane confinement collar being configured to extend over a hydrogen separation membrane, the confinement collar being configured to extend from a connection interface between the hydrogen separation membrane and a connector and to extend over the hydrogen separation membrane, the confinement collar having a longitudinal axis and comprising: an expansion section configured to extend axially from a restricted end to an expanded diameter above the hydrogen separation membrane relative to the longitudinal axis, the restricted end configured to extend around the hydrogen separation membrane relative to the longitudinal axis at or near the connection interface and having an inner surface defining a restricted diameter (C) configured to extend around an outer surface of the hydrogen separation membrane, wherein the expansion section comprises a transition section extending from the limiting end and comprising a curved surface having a transition radius of at least 0.1C, and wherein the expansion section comprises an angled or curved section extending from the transition section, in which section: The diameter of the restraining collar expands from the restraining diameter to the expanded diameter at an average expansion angle relative to the longitudinal axis of the angled or curved section, the average expansion angle comprising a non-zero angle of less than 17.5 degrees, and the expanded diameter comprises at least 1.01C.

45. The restraining collar of claim 44, wherein: The expansion section extends at least 0.2C relative to the longitudinal axis.

46. ​​The restraining collar of claim 44 or claim 45, wherein: The restricted end includes a restricted section configured to extend axially from the connection end to the expansion section above the hydrogen separation membrane relative to the longitudinal axis, the restricted section having an inner surface extending around the longitudinal axis at the restricted diameter C, The transition section extends from a transition between the limiting section and the expansion section.

47. The restraining collar of any one of claims 44 to 46, wherein: The hydrogen separation membrane has an outer diameter D, and the limiting diameter C is comprised between 0.95D and 1.05D, preferably between 0.99D and 1.05D, and more preferably between 1D and 1.05D.

48. The restraining collar of any one of claims 44 to 47, wherein: The confinement section is configured to extend from the connection interface to the transition section by at least 0.25C, preferably 0.25C to 2C, more preferably 0.25C to 1.5C, more preferably 0.25C to 1C above the hydrogen separation membrane.

49. The restraining collar of any one of claims 44 to 48, wherein: The expanded diameter is at least 1.02C, preferably at least 1.05C, more preferably at least 1.1C.

50. The restraining collar of any one of claims 44 to 49, wherein: The average expansion angle is from 0.5 to 6 degrees, preferably from 3 to 5 degrees.

51. The restraining collar of any one of claims 44 to 50, wherein: The transition radius is comprised between 0.1C and 10C, preferably between 0.5C and 5C, and more preferably between 1C and 5C.

52. The restraining collar of any one of claims 44 to 51, wherein: The expansion section extends at least 0.3C, preferably at least 0.4C, more preferably at least 0.5C relative to the longitudinal axis.

53. The restraining collar of any one of claims 44 to 52, wherein: The restraining collar includes a collar fastening section configured to be fastened to a section of the connector, the collar fastening section including fastening structures configured to interconnect the restraining collar to a mating fastening structure of the connector.

54. The restraining collar of claim 53, wherein: The fastening structure includes a threaded connection configured to matingly fasten to threads located on the connector.

55. The restraining collar of any one of claims 44 to 54, wherein: The restraining collar also includes an end cap configured to form an end seal around the connector.

56. The restraining collar of any one of claims 44 to 55, further comprising: a sealing section configured to extend over the connector to a distal fastening end; as well as A compression fitting is configured to be fastened to the distal fastening end of the sealing segment, the compression fitting including at least one ferrule configured to seal around a segment of the connector when the compression fitting is fastened to the distal fastening end of the sealing segment.

57. The restraining collar of claim 56, wherein: The at least one ferrule includes a graphite ferrule.

58. The restraining collar of claim 56 or claim 57, wherein: The compression fitting includes a sealing nut configured to be threadably fastened to the distal fastening end of the sealing segment.

59. The restraining collar of any one of claims 56 to 58, wherein: The sealing segment includes a fastening structure configured to interconnect the restraining collar to a mating fastening structure of the connector.

60. The restraining collar of any one of claims 44 to 59, wherein: The restraining collar comprises a tubular configuration, preferably a substantially cylindrical configuration.

61. The restraining collar of any one of claims 44 to 60, wherein: The restraining collar is composed of at least one of aluminum, an aluminum alloy, steel, stainless steel, nickel-chromium-iron alloy, brass, or a combination thereof.

62. A hydrogen separation membrane confinement collar, when used over a joint between a hydrogen separation membrane and a metal connector, the confinement collar being configured to extend from a connection interface between the hydrogen separation membrane and the connector and over the hydrogen separation membrane, the confinement collar having a longitudinal axis and comprising: an expansion section configured to extend axially from a restricted end to an expanded diameter above the hydrogen separation membrane relative to the longitudinal axis, the restricted end configured to extend around the hydrogen separation membrane relative to the longitudinal axis at or near the connection interface and having an inner surface defining a restricted diameter (C) configured to extend around an outer surface of the hydrogen separation membrane, wherein the expansion section comprises a transition section extending from the limiting end and comprising a curved surface having a transition radius of at least 0.1C, And wherein the expansion section comprises an angled or curved section extending from the transition section, in which section: the diameter of the restraining collar expands from the restraining diameter to the expanded diameter comprising at least 1.01C.

63. A method of coupling and sealing a hydrogen separation membrane to a metal connector, the method comprising: mounting an end segment of a metal hydrogen separation membrane on or against a connector structure of a connector, the connector being formed of a metal different from the hydrogen separation membrane, the hydrogen separation membrane having an outer diameter (D) about the longitudinal axis, the hydrogen separation membrane and the connector structure being in contact at a connection interface in which an end face of the hydrogen separation membrane is proximate, substantially abuts or overlaps an adjacent face of the connector structure; coupling the hydrogen separation membrane to the connector structure to couple and seal the hydrogen separation membrane to the connector through the connection interface; as well as A confinement collar according to any one of claims 44 to 62 is positioned above the hydrogen separation membrane to extend at least from the connection interface and to extend axially above the hydrogen separation membrane relative to the longitudinal axis.

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