Hydrogen gas high pressure storage system

Abstract

A device for the storage of compressed hydrogen gas comprises a plurality of glass capillary tubes each having a sealed extremity and an open extremity, wherein said plurality of glass capillary tubes is sheathed in an external tubular cover, and wherein the open end of a bundle of said tubular covers is housed in an adaptor, and wherein said adaptor is suitable to allow compressed hydrogen gas to be added to, and to prevent said hydrogen gas from escaping from, said glass capillary tubes.

Claims

1. A device for the storage of compressed hydrogen gas, comprising a multi-capillary structure consisting of a plurality of glass capillary tubes each having a sealed extremity and an open extremity, wherein said plurality of glass capillary tubes are sheathed in an external tubular cover; and a plurality of said multi-capillary structures is bundled together such that the open end of the resulting bundle is housed in an adaptor, and wherein said adaptor is suitable to allow compressed hydrogen gas to be added to, and to prevent said hydrogen gas from escaping from, said glass capillary tubes.

2. A device according to claim 1, wherein the bundle of tubular covers is connected to the adaptor at the open end with gluing material.

3. A device according to claim 2, wherein the gluing material is an epoxy resin.

4. A device according to claim 3, further comprising sealing material.

5. A device according to claim 1, wherein the adaptor is provided with a sealing valve.

6. A device according to claim 5, wherein the valve is integral with the adaptor.

7. A device according to claim 5, wherein the valve is coupled to the adaptor.

8. The device of claim 1 wherein each capillary tube is formed by, applying a glass cupping to one open end of an open-ended capillary tube and then melting the glass at said end.

9. A system for the storage of compressed hydrogen gas, comprising an array of two or more devices, each comprising a multi-capillary structure consisting of a plurality of glass capillary tubes each having a sealed extremity and an open extremity, wherein said plurality of glass capillary tubes are sheathed in an external tabular cover; and a plurality of said multi-capillary structures is bundled together such that the open end of the resulting bundle is housed in an adaptor, and wherein said adaptor is suitable to allow compressed hydrogen gas to be added to, and to prevent said hydrogen gas from escaping from, said glass capillary tubes; said two or more devices being connected to a common conduit for the addition of gas to, and withdrawal of gas from, said devices.

10. A fuel cell comprising as the hydrogen-storage element one or more devices according to claim 1.

11. A fuel cell according to claim 10, for use in powering electronic devices.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) In the drawings:

(2) FIG. 1 is a perspective view of an MC (multi-capillary structure), according to one embodiment of the invention;

(3) FIG. 2 is a perspective view of a group of MCs-MMC (multi multi-capillary structure) of FIG. 1;

(4) FIG. 3 is an array of MMCs, according to another embodiment of the invention;

(5) FIG. 4 is a diagram of a fuel-providing system comprising an array of MMC; and

(6) FIG. 5 is another diagram of a fuel-providing system further comprising a check valve and a release valve.

DETAILED DESCRIPTION OF THE INVENTION

(7) The invention relates to a gas-containing system and method. The following description refers to hydrogen gas, but obviously the system may be exploited to store additional and/or alternative gases, as long as the pressure of said gases does not exceed the maximum pressure that the system can accommodate.

(8) The gas is caused to flow into a thin glass tube, which will also be referred to herein as capillary. The cross-section of the capillary can be round or of any other geometrical shape, such as a hexagonal.

(9) The glass tubes are made of a material having high tensile strength 20 and low mass density . For example, materials that meet the condition />_1700 MPa-cm3/g are suitable for the glass tubes. Examples of materials suitable for the capillary tubes include, but are not limited to, borosilicate glass, MgAlSi glass, S-2 Glass, R-glass available from Saint-Gobain Vetrotex Textiles, T-Glass available from Nitto Boseki Co., Ltd. (Nittobo), fused quartz, polymers (e.g., Kevlar, 25 TwaronXM), etc.

(10) Generally, the glass tubes can have any desired length. The external diameter of the glass tubes can be in the range of about 1 micrometer to about 500 micrometers. A number of the capillary glass tubes in one MMC (see FIG. 2) can, for example, be in the range of 50 to 1,000,000. These dimensions of the capillaries are strongly dependent on pressure resistance, possibility of easy manufacturing etc. whereas the dimensions of the arrays (various number of MMC) are dependent on the manufacturing process, opening procedure and the actual application.

(11) Methods for fabrication of hollow microcylinders (i.e., capillary glass tubes) and microcylindrical array structures are known per se. In particular, various microcylindrical (capillary) arrays made from glass and/or plastics are widely used in x-ray optics and photonics. Generally, the process of fabrication of microcylindrical arrays is divided into three main stages: (i) drawing capillaries with relatively large diameter, (ii) re-drawing them 10 into a bundle of capillaries with smaller diameter, and (iii) sintering capillaries into the array. Existing technology enables one to produce vast arrays with a capillary diameter down to 1 micron or even less, and a wall thickness-to-diameter ratio less than 5%. For example, capillary arrays suitable for the purpose of the present invention can be obtained from Paradigm Optics, Inc.; 9600 NE 126th Ave, Suite 2540 Vancouver, Wash. 15 98682 USA; Hilgenberg GmbH, Strauchgraben 2, D-34323 Malsfeld, Germany; INCOM 294 Southbridge Road, Charlton, Mass. 01507; etc.

(12) A group of capillaries is attached together to form a multi-capillary structure (MC). The MC outer cover also has a tubular shape. FIG. 1 shows an MC 101 with a hexagonal cross-section, according to one embodiment of the invention. One end of the MC 101 is sealed by a glass cupping element, which in this example is shaped as a half sphere 102, hereinafterhalf-sphere. For better orientation, the end that comprises a half-sphere is designated as the bottom. The connection between a tube and a half-sphere is performed by melting the glass while applying pressure on both parts, one against the other.

(13) As shown in FIG. 2, a number of MCs can be attached and form an even larger storage systemmulti-multi-capillary (MMC). An MC or a group of MCsMMC are connected to an adaptor at the open (top) end of the capillariesa unit which allows the addition and release of a gas into and from each tube. A valve can be provided in the adaptor or connected thereto, to prevent gas from escaping from the storage. FIG. 2 shows an MMC 201 connected to an adaptor 202. The attachment of an MC or an MMC to an adaptor can be performed for example by a glue such as epoxy resin. If necessary after the attachment of the adaptor to the MC/MMC, an additional sealing material can be used. One example of a suitable adaptor is one that is made of stainless steel 1.4301 and designed to securely hold the glass-steel connection at pressure up to 40 MPa.

(14) An exemplary adaptor made of SS 1.4301 has a wall thickness of 0.75 mm and is suitable to store gas at a pressure of up to 40 MPa, it is glued for a length of the glass sheath of 53 mm using Loctite 9483 A&B. The resin is cures at 30 C. for 24 hours.

(15) As shown in FIG. 3, another form of storage system can be an array of MMCs, according to another embodiment of the invention. Every MMC 301 is connected to its own adaptor 302, and every adaptor is connected to a conduit 303. When all of the MMCs in the array are connected to one or more conduits, it provides for a convenient addition and extraction of gas into and from the storage system, and thus the procedure is performed only once for every group of MMCs connected to the same conduit 303.

(16) FIG. 4 is a diagram of a fuel-providing system comprising an array of MMC. The fuel cell 401 is where the chemical reaction occurs, but the gas used in the process needs to enter the fuel cell 401 at a relatively low pressure, for example 0.2 MPa, and since it leaves the MMCs 402 at a pressure of up to 20 MPa, in this illustrative scheme a pressure regulator 403 is provided between the fuel cell 401 and the MMCs 402. A fast coupling 404 can also be provided.

(17) FIG. 5 is another diagram of a fuel-providing system further comprising a check valve 501 and a release valve 502. The additional two components are provided in this specific embodiment of the invention for safety reasons. The check valve 501 can detect hazardous situation relaying on pressure values measured by said valve 501. If the pressure in the system is too high, the release valve 502 is operated by check valve 501, for pressure release and regulation.

(18) All the above description has been provided for the purpose of illustration and it is not meant to limit the invention in any way except as provided for by the appended claims.