Abstract:
The present application is directed to a gas-generating apparatus and various pressure regulators or pressure-regulating valves. Hydrogen is generated within the gas-generating apparatus and is transported to a fuel cell. The transportation of a first fuel component to a second fuel component to generate of hydrogen occurs automatically depending on the pressure of a reaction chamber within the gas-generating apparatus. The pressure regulators and flow orifices are provided to regulate the hydrogen pressure and to minimize the fluctuation in pressure of the hydrogen received by the fuel cell. Connecting valves to connect the gas-generating apparatus to the fuel cell are also provided.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     This application is a continuation-in-part of U.S. application Ser. No. 10/629,006, filed Jul. 29, 2003, U.S. App. No. 11/067,167, filed on Feb. 25, 2005, U.S. provisional App. No. 60/689,538 filed on Jun. 13, 2005, and U.S. provisional App. No. 60/689,539 filed on Jun. 13, 2005, all of which are incorporated herein in their entireties by reference. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     Fuel cells are devices that directly convert chemical energy of reactants, i.e., fuel and oxidant, into direct current (DC) electricity. For an increasing number of applications, fuel cells are more efficient than conventional power generation, such as combustion of fossil fuel, as well as portable power storage, such as lithium-ion batteries.  
         [0003]     In general, fuel cell technology includes a variety of different fuel cells, such as alkali fuel cells, polymer electrolyte fuel cells, phosphoric acid fuel cells, molten carbonate fuel cells, solid oxide fuel cells and enzyme fuel cells. Today&#39;s more important fuel cells can be divided into several general categories, namely (i) fuel cells utilizing compressed hydrogen (H 2 ) as fuel; (ii) proton exchange membrane (PEM) fuel cells that use alcohols, e.g., methanol (CH 3 OH), metal hydrides, e.g., sodium borohydride (NaBH 4 ), hydrocarbons, or other fuels reformed into hydrogen fuel; (iii) PEM fuel cells that can consume non-hydrogen fuel directly or direct oxidation fuel cells; and (iv) solid oxide fuel cells (SOFC) that directly convert hydrocarbon fuels to electricity at high temperature.  
         [0004]     Compressed hydrogen is generally kept under high pressure and is therefore difficult to handle. Furthermore, large storage tanks are typically required and cannot be made sufficiently small for consumer electronic devices. Conventional reformat fuel cells require reformers and other vaporization and auxiliary systems to convert fuels to hydrogen to react with oxidant in the fuel cell. Recent advances make reformer or reformat fuel cells promising for consumer electronic devices. The most common direct oxidation fuel cells are direct methanol fuel cells or DMFC. Other direct oxidation fuel cells include direct ethanol fuel cells and direct tetramethyl orthocarbonate fuel cells. DMFC, where methanol is reacted directly with oxidant in the fuel cell, is the simplest and potentially smallest fuel cell and also has promising power application for consumer electronic devices. SOFC convert hydrocarbon fuels, such as butane, at high heat to produce electricity. SOFC requires relatively high temperature in the range of 1000° C. for the fuel cell reaction to occur.  
         [0005]     The chemical reactions that produce electricity are different for each type of fuel cell. For DMFC, the chemical-electrical reaction at each electrode and the overall reaction for a direct methanol fuel cell are described as follows:  
         [0006]     Half-reaction at the anode: 
 
CH 3 OH+H 2 O→CO 2 +6H + +6e − 
 
         [0007]     Half-reaction at the cathode: 
 
1.5O 2 +6H + +6e − →3H 2 O 
 
         [0008]     The overall fuel cell reaction: 
 
CH 3 OH+1.5O 2 →CO 2 +2H 2 O 
 
         [0009]     Due to the migration of the hydrogen ions (H + ) through the PEM from the anode to the cathode and due to the inability of the free electrons (e − ) to pass through the PEM, the electrons flow through an external circuit, thereby producing an electrical current through the external circuit. The external circuit may be used to power many useful consumer electronic devices, such as mobile or cell phones, calculators, personal digital assistants, laptop computers, and power tools, among others.  
         [0010]     DMFC is discussed in U.S. Pat. Nos. 5,992,008 and 5,945,231, which are incorporated by reference herein in their entireties. Generally, the PEM is made from a polymer, such as Nafion® available from DuPont, which is a perfluorinated sulfonic acid polymer having a thickness in the range of about 0.05 mm to about 0.50 mm, or other suitable membranes. The anode is typically made from a Teflonized carbon paper support with a thin layer of catalyst, such as platinum-ruthenium, deposited thereon. The cathode is typically a gas diffusion electrode in which platinum particles are bonded to one side of the membrane.  
         [0011]     In another direct oxidation fuel cell, borohydride fuel cell (DBFC) reacts as follows:  
         [0012]     Half-reaction at the anode: 
 
BH 4 -+8OH—→BO 2 -+6H 2 O+8e- 
 
         [0013]     Half-reaction at the cathode: 
 
2O 2 +4H 2 O+ 8   e -→8OH—
 
         [0014]     In a chemical metal hydride fuel cell, sodium borohydride is reformed and reacts as follows: 
 
NaBH 4 +2H 2 O→(heat or catalyst)→4(H 2 )+(NaBO 2 ) 
 
         [0015]     Half-reaction at the anode: 
 
H 2 →2H + +2e − 
 
         [0016]     Half-reaction at the cathode: 
 
2(2H + +2e − )+O 2 →2H 2 O 
 
         [0017]     Suitable catalysts for this reaction include platinum and ruthenium, and other metals. The hydrogen fuel produced from reforming sodium borohydride is reacted in the fuel cell with an oxidant, such as O 2 , to create electricity (or a flow of electrons) and water by-product. Sodium borate (NaBO 2 ) by-product is also produced by the reforming process. A sodium borohydride fuel cell is discussed in U.S. Pat. No. 4,261,956, which is incorporated by reference herein in its entirety.  
         [0018]     One of the most important features for fuel cell application is fuel storage. Another important feature is to regulate the transport of fuel out of the fuel cartridge to the fuel cell. To be commercially useful, fuel cells such as DMFC or PEM systems should have the capability of storing sufficient fuel to satisfy the consumers&#39; normal usage. For example, for mobile or cell phones, for notebook computers, and for personal digital assistants (PDAs), fuel cells need to power these devices for at least as long as the current batteries and, preferably, much longer. Additionally, the fuel cells should have easily replaceable or refillable fuel tanks to minimize or obviate the need for lengthy recharges required by today&#39;s rechargeable batteries.  
         [0019]     One disadvantage of the known hydrogen gas generators is that once the reaction starts the gas generator cartridge cannot control the reaction. Thus, the reaction will continue until the supply of the reactants run out or the source of the reactant is manually shut down.  
         [0020]     Accordingly, there is a desire to obtain a hydrogen gas generator apparatus that is capable of self-regulating the flow of at least one reactant into the reaction chamber and other devices to regulate the flow of fuel.  
       SUMMARY OF THE INVENTION  
       [0021]     The present application is directed to a gas-generating apparatus and various pressure regulators or pressure-regulating valves. Hydrogen is generated within the gas-generating apparatus and is transported to a fuel cell. The transportation of a first fuel component to a second fuel component to generate of hydrogen occurs automatically depending on the pressure of a reaction chamber within the gas-generating apparatus. The pressure regulators, including flow orifices, are provided to regulate the hydrogen pressure and to minimize the fluctuation in pressure of the hydrogen received by the fuel cell. Connecting valves to connect the gas-generating apparatus to the fuel cell are also provided. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0022]     In the accompanying drawings, which form a part of the specification and are to be read in conjunction therewith and in which like reference numerals are used to indicate like parts in the various views:  
         [0023]      FIG. 1  is a cross-sectional schematic view of a gas-generating apparatus according to the present invention;  FIG. 1A  is an enlarged partial cross-sectional view of a solid fuel container for use in the gas-generating apparatus of  FIG. 1 ;  FIG. 1B  is an enlarged partial cross-sectional view of an alternate solid fuel container for use in the gas-generating apparatus of  FIG. 1 ;  FIG. 1C  is an alternate embodiment of  FIG. 1B ;  FIG. 1D  is a cross-sectional view of an alternate embodiment of a fluid conduit;  
         [0024]      FIG. 2A  is a cross-sectional view of a shut-off or connection valve for use in the gas-generating apparatus of  FIG. 1  shown in the disconnected and closed position;  FIG. 2B  is a cross-sectional view of the shut-off valve shown in  FIG. 2A  shown in the connected and open position;  
         [0025]      FIG. 3  is a cross-sectional view of a pressure-regulated fluid nozzle or valve for use in the gas-generating apparatus of  FIG. 1 ;  
         [0026]      FIG. 4A  is a cross-sectional view of a pressure-regulating valve for use in the gas-generating apparatus of  FIG. 1 ;  FIG. 4B  is an exploded perspective view of the pressure-regulating valve of  FIG. 4A ;  FIG. 4C  is a cross-sectional view of an alternate pressure-regulating valve;  FIG. 4D  is an exploded perspective view of the pressure-regulating valve of  FIG. 4C ;  
         [0027]      FIG. 5A  is a cross-sectional view of another pressure-regulating valve connected to a first valve component of the shut-off valve of  FIG. 2 ; FIGS.  5 B-D are cross-sectional views showing the pressure-regulating valve and the first valve component with a second valve component of the shut-off valve in the unconnected, connected/closed and connected/open positions;  
         [0028]      FIG. 6A  is a cross-sectional view of a pressure-regulating valve for use in the gas-generating apparatus of  FIG. 1 ;  FIG. 6B  is an exploded view of the pressure-regulating valve of  FIG. 6A ; and  
         [0029]      FIGS. 7A and 7B  are cross-sectional views of a variable diameter orifice for use with the pressure-regulating valves of the present invention. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0030]     As illustrated in the accompanying drawings and discussed in detail below, the present invention is directed to a fuel supply, which stores fuel cell fuels, such as methanol and water, methanol/water mixture, methanol/water mixtures of varying concentrations, pure methanol, and/or methyl clathrates described in U.S. Pat. Nos. 5,364,977 and 6,512,005 B2, which are incorporated by reference herein in their entirety. Methanol and other alcohols are usable in many types of fuel cells, e.g., DMFC, enzyme fuel cells and reformat fuel cells, among others. The fuel supply may contain other types of fuel cell fuels, such as ethanol or alcohols; metal hydrides, such as sodium borohydrides; other chemicals that can be reformatted into hydrogen; or other chemicals that may improve the performance or efficiency of fuel cells. Fuels also include potassium hydroxide (KOH) electrolyte, which is usable with metal fuel cells or alkali fuel cells, and can be stored in fuel supplies. For metal fuel cells, fuel is in the form of fluid borne zinc particles immersed in a KOH electrolytic reaction solution, and the anodes within the cell cavities are particulate anodes formed of the zinc particles. KOH electrolytic solution is disclosed in U.S. Pat. App. Pub. No. US 2003/0077493, entitled “Method of Using Fuel Cell System Configured to Provide Power to One or More Loads,” published on Apr. 24, 2003, which is incorporated by reference herein in its entirety. Fuels can also include a mixture of methanol, hydrogen peroxide and sulfuric acid, which flows past a catalyst formed on silicon chips to create a fuel cell reaction. Moreover, fuels include a blend or mixture of methanol, sodium borohydride, an electrolyte, and other compounds, such as those described in U.S. Pat. Nos. 6,554,877, 6,562,497 and 6,758,871, which are incorporated by reference herein in their entireties. Furthermore, fuels include those compositions that are partially dissolved in a solvent and partially suspended in a solvent, described in U.S. Pat. No. 6,773,470 and those compositions that include both liquid fuel and solid fuels, described in U.S. Pat. Appl. Pub. No. US 2002/0076602. Suitable fuels are also disclosed in co-owned, co-pending U.S. Pat. Appl. No. 60/689,572, entitled “Fuels for Hydrogen-Generating Cartridges,” filed on Jun. 13, 2005. These references are also incorporated by reference herein in their entireties.  
         [0031]     Fuels can also include a metal hydride such as sodium borohydride (NaBH 4 ) and water, discussed above. Fuels can further include hydrocarbon fuels, which include, but are not limited to, butane, kerosene, alcohol, and natural gas, as set forth in U.S. Pat. Appl. Pub. No. US 2003/0096150, entitled “Liquid Hereto-Interface Fuel Cell Device,” published on May 22, 2003, which is incorporated by reference herein in its entirety. Fuels can also include liquid oxidants that react with fuels. The present invention is therefore not limited to any type of fuels, electrolytic solutions, oxidant solutions or liquids or solids contained in the supply or otherwise used by the fuel cell system. The term “fuel” as used herein includes all fuels that can be reacted in fuel cells or in the fuel supply, and includes, but is not limited to, all of the above suitable fuels, electrolytic solutions, oxidant solutions, gaseous, liquids, solids, and/or chemicals including additives and catalysts and mixtures thereof.  
         [0032]     As used herein, the term “fuel supply” includes, but is not limited to, disposable cartridges, refillable/reusable cartridges, containers, cartridges that reside inside the electronic device, removable cartridges, cartridges that are outside of the electronic device, fuel tanks, fuel refilling tanks, other containers that store fuel and the tubings connected to the fuel tanks and containers. While a cartridge is described below in conjunction with the exemplary embodiments of the present invention, it is noted that these embodiments are also applicable to other fuel supplies and the present invention is not limited to any particular type of fuel supply.  
         [0033]     The fuel supply of the present invention can also be used to store fuels that are not used in fuel cells. These applications can include, but are not limited to, storing hydrocarbons and hydrogen fuels for micro gas-turbine engines built on silicon chips, discussed in “Here Come the Microengines,” published in The Industrial Physicist (December 2001/January 2002) at pp. 20-25. As used in the present application, the term “fuel cell” can also include microengines. Other applications can include storing traditional fuels for internal combustion engines and hydrocarbons, such as butane for pocket and utility lighters and liquid propane.  
         [0034]     Suitable known hydrogen-generating apparatus are disclosed in commonly-owned, co-pending U.S. Pat. Appl. Pub. No. US 2005-0074643 A1 and U.S. Pat. Appl. Pub. No. US 2005-0266281, and co-pending U.S. patent application Ser. No. 11/066,573 filed on Feb. 25, 2005. The disclosures of these references are incorporated by reference herein in their entireties.  
         [0035]     The gas-generating apparatus of the present invention may include a reaction chamber, which may include an optional first reactant, and a reservoir having a second reactant. The first and second reactants can be a metal hydride, e.g., sodium borohydride, and water. The reactants can be in gaseous, liquid, aqueous or solid form. Preferably, the first reactant stored in the reaction chamber is a solid metal hydride or metal borohydride with selected additives and catalysts such as ruthenium, and the second reactant is water optionally mixed with selected additives and catalysts. Water and metal hydride of the present invention react to produce hydrogen gas, which can be consumed by a fuel cell to produce electricity. Other suitable reactants or reagents are disclosed in the parent applications, previously incorporated above.  
         [0036]     Additionally, the gas-generating apparatus can include a device or system that is capable of controlling the transport of a second reactant from the reservoir to the reaction chamber. The operating conditions inside the reaction chamber and/or the reservoir, preferably a pressure inside the reaction chamber, are capable of controlling the transport of the second reactant in the reservoir to the reaction chamber. For example, the second reactant in the reservoir can be introduced into the reaction chamber when the pressure inside the reaction chamber is less than a predetermined value, preferably less than the pressure in the reservoir, and, more preferably less than the pressure in the reservoir by a predetermined amount. It is preferable that the flow of the second reactant from the reservoir into the reaction chamber is self-regulated. Thus, when the reaction chamber reaches a predetermined pressure, preferably a predetermined pressure above the pressure in the reservoir, the flow of the second reactant from the reservoir into the reaction chamber can be stopped to stop the production of hydrogen gas. Similarly, when the pressure of the reaction chamber is reduced below the pressure of the reservoir, preferably below the pressure in the reservoir by a predetermined amount, the second reactant can flow from the reservoir into the reaction chamber. The second reactant in the reservoir can be introduced into the reaction chamber by any known method including, but not limited to, pumping, osmosis, capillary action, pressure differential valves, other valve(s), or combinations thereof. The second reactant can also be pressurized with springs or pressurized liquids and gases. Preferably, the second reactant is pressurized with liquefied hydrocarbons, such as liquefied butane.  
         [0037]     Referring to  FIG. 1 , an inventive fuel supply system is shown. The system includes a gas-generating apparatus  12  contained within a housing  13  and is configured to be connected to a fuel cell (not shown) via a fuel conduit  16  and a valve  34 . Preferably, fuel conduit  16  initiates within gas-generating apparatus  12 , and valve  34  is in fluid communication with conduit  16 . Fuel conduit  16  can be a flexible tube, such as a plastic or rubber tube, or can be a substantially rigid part connected to housing  13 .  
         [0038]     Within housing  13 , gas-generating apparatus  12  preferably includes two main compartments: a fluid fuel component reservoir  44  containing a fluid fuel component  22  and a reaction chamber  18  containing a solid fuel component  24 . Reservoir  44  and reaction chamber  18  are sealed off from one another until the production of a fuel gas, such as hydrogen, is desired by reacting fluid fuel component  22  with solid fuel component  24 . Housing  13  is preferably divided by interior wall  19  to form fluid reservoir  44  and reaction chamber  18 .  
         [0039]     Reservoir  44  may preferably, however, include a liner, bladder or similar fluid container  21  to contain fluid or liquid fuel component  22  as shown. Fluid fuel component  22  preferably includes water and/or an additive/catalyst or other liquid reactants. Additional appropriate fluid fuel components and additives are further discussed herein. Suitable additives/catalysts include, but are not limited to, anti-freezing agents (e.g., methanol, ethanol, propanol and other alcohols), catalysts (e.g., cobalt chloride and other known catalysts), pH adjusting agents (e.g., acids such as sulfuric acid and other common acids). Preferably, fluid fuel component  22  is pressurized, such as by springs or by pressurized/liquefied gas (butane or propane), although it may also be unpressurized. When liquefied hydrocarbon is used, it is injected into reservoir  44  and is contained in the space between liner  21  and housing  13 .  
         [0040]     Reservoir  44  and reaction chamber  18  are fluidly connected by a fluid transfer conduit  88 . Fluid transfer conduit  88  is connected to conduit  15 , which is in fluid communication with liquid fuel component  22  within liner  21 , and one or more conduits  17 , which brings the liquid fuel component  22  into contact with the solid fuel component  24 . Orifice  15  can be connected directly to conduit  88 , or as shown in  FIG. 1  it can be connected to a channel  84  defined on the outside surface of plug  86  which defines conduit  88  therewithin. Hole  87  connects surface channel  84  to conduit  88 . The function of plug  86  is further defined hereafter. Fluid transfer conduit  88  can also be a channel or similar void formed in housing  13 , or external tubing located outside of housing  13 . Other configurations are also appropriate.  
         [0041]     Reaction chamber  18  is contained within housing  13  and separated from fluid fuel component reservoir  44  by interior wall  19  and is preferably made of a fluid impenetrable material, such as a metal, for example, stainless steel, or a resin or plastic material. As liquid fuel component  22  and solid fuel component  24  are mixed within reaction chamber  18  to produce a fuel gas, such as hydrogen, reaction chamber  18  also preferably includes a pressure relief valve  52  located in housing  13 . Pressure relief valve  52  is preferably a pressure-triggered valve, such as a check valve or a duckbill valve, which automatically vents produced fuel gas should the pressure within reaction chamber, P 18 , reach a specified triggering pressure. Another pressure relief valve can be installed on fluid fuel component reservoir  44 .  
         [0042]     Solid fuel component  24 , which can be powders, granules, or other solid forms, is disposed within a solid fuel container  23 , which, in this embodiment, is a gas permeable bladder, liner or bag. Fillers and other additives and chemicals can be added to solid fuel component  24  to improve its reaction with the liquid reactant. Preferably, additives that can be corrosive to valves and other elements within fluid transfer conduit  88 , conduits  15  and  17  should be included with solid fuel  24 . Solid fuel component  24  is packed inside solid fuel container  23 , which is preferably cinched or wrapped tightly around one or more fluid dispersion elements  89 ; for example with rubber or elastic bands, such as rubber or metal bands, with heat shrunk wraps, pressure adhesive tapes or the like. Solid fuel container  23  can also be formed by thermoform. In one example, solid fuel container  23  comprises a plurality of films that are selectively perforated to control the flow of liquid reactant, gas and/or by-products therethrough. Each fluid dispersion element  89  is in fluid communication with conduits  17 , within which the liquid fuel is transported to the solid fuel. Dispersion element  89  is preferably a rigid tube-like hollow structure made of a non-reactive material having openings  91  along its length and at its tip to assist in the maximum dispersal of fluid fuel component  22  to contact solid fuel component  24 . Preferably, at least some of the openings  91  in fluid dispersion element  89  include capillary fluid conduits  90 , which are relatively small tubular extensions to disperse the fluid even more effectively throughout solid fuel component  24 . Capillary conduits  90  can be fillers, fibers, fibrils or other capillary conduits. Each fluid dispersion element  89  is supported within reaction chamber  18  by a mount  85 , which is also the point at which fluid dispersion element  89  is connected to conduits  17  and to fluid transfer conduit  88 .  
         [0043]     The inner diameter of fluid dispersion element  89  is sized and dimensioned to control the volume and speed that liquid fuel component  22  is transported therethrough. In certain instances, the effective inner diameter of element  89  needs to be sufficiently small, such that the manufacture of such a small tube may be difficult or expensive. In such instances, a larger tube  89   a  can be used with a smaller rod  89   b  disposed within the larger tube  89   a  to reduce the effective inner diameter of the larger tube  89   a . The liquid fuel component is transported through the annular space  89   c  between the tube and the inner rod, as shown in  FIG. 1D .  
         [0044]     In another embodiment, to increase the permeability of the liquid fuel component  22  through the solid fuel component  24 , hydrophilic materials, such as fibers, foam chopped fibers or other wicking materials, can be intermixed with the solid fuel component  24 . The hydrophilic materials can form an interconnected network within solid fuel component  24 , but the hydrophilic materials do not need to contact each other within the solid fuel component to improve permeability.  
         [0045]     Solid fuel container  23  may be made of many materials and can be flexible or substantially rigid. In the embodiment shown in  FIG. 1A , solid fuel container  23  is preferably made of a single layer  54  of a gas-permeable, liquid impermeable material such as CELGARD® and GORE-TEX®. Other gas permeable, liquid impermeable materials usable in the present invention include, but are not limited to, SURBENT® Polyvinylidene Fluoride (PVDF) having a porous size of from about 0.1 μm to about 0.45 μm, available from Millipore Corporation. The pore size of SURBENT® PVDF regulates the amount of liquid fuel component  22  or water exiting the system. Materials such as electronic vent-type material having 0.2 μm hydro, available from W. L. Gore &amp; Associates, Inc., may also be used in the present invention. Additionally, sintered and/or ceramic porous materials having a pore size of less than about 10 μm, available from Applied Porous Technologies Inc., are also usable in the present invention. Additionally, or alternatively, the gas permeable, liquid impermeable materials disclosed in commonly owned, co-pending U.S. patent application Ser. No. 10/356,793 are also usable in the present invention, all of which are incorporated by reference herein in their entireties. Using such materials allows for the fuel gas produced by the mixing of fluid fuel component  22  and solid fuel component  24  to vent through solid fuel container  23  and into reaction chamber  18  for transfer to the fuel cell (not shown), while restricting the liquid and/or paste-like by-products of the chemical reaction to the interior of solid fuel container  23 .  
         [0046]      FIG. 1B  shows an alternate construction for solid fuel container  23 . In this embodiment, the walls of solid fuel container  23  are made of multiple layers: an outer layer  57  and an inner layer  56  separated by an absorbent layer  58 . Both inner layer  56  and outer layer  57  may be made of any material known in the art capable of having at least one slit  55  formed therein. Slits  55  are openings in inner layer  56  and outer layer  57  to allow the produced fuel gas to vent from solid fuel container  23 . To minimize the amount of fluid fuel component  22  and/or paste-like by-products that may exit through slits  55 , absorbent layer  58  is positioned between inner layer  56  and outer layer  57  to form a barrier. Absorbent layer  58  may be made from any absorbent material known in the art, but is preferably capable of absorbing liquid while allowing gas to pass through the material. One example of such a material is paper fluff containing sodium polyacrylate crystals; such a material is commonly used in diapers. Other examples include, but are not limited to, fillers, non-wovens, papers and foams. As will be recognized by those in the art, solid fuel container  23  may include any number of layers, alternating between layers containing slits  55  and absorbent layers.  
         [0047]     In one example shown in  FIG. 1C , solid fuel component  24  is encased in four layers  54   a ,  54   b ,  54   c  and  54   d . These layers are preferably gas permeable and liquid impermeable. Alternatively, each layer can be made from any material with a plurality of holes or slits  55 , as shown, to allow the produced gas to pass through. Disposed between adjacent layers  54   a - d  are absorbent layers  58 . In this embodiment, the flow path for the produced gas and the by-products, if any, is made tortuous to encourage more liquid fuel component  22  to remain in contact with solid fuel component  24  longer to produce more gas. As shown, while the innermost layer  54  is perforated on both sides, the next layer  54   b  is perforated only on one side. The next layer  54   c  is also perforated on one side, but opposite to the perforated side of layer  54   b . Layer  54   d  is perforated on one side, but opposite to the perforated side of layer  54   c  and so on. Alternatively, instead of using partially perforated layers  54   a - b  wrapping around solid fuel component  24 , liners or bags made with a permeable portion and non-permeable portion can be used instead, with the permeable portion of one liner located opposite from the permeable portion of the next outer layer.  
         [0048]     Disposed within fluid transfer conduit  88  is preferably a fluid transfer valve  33  to control the flow of fluid fuel component  22  into reaction chamber  18 . Fluid transfer valve  33  may be any type of pressure-opened, one-way valve known in the art, such as a check valve (as shown in  FIG. 1 ), a solenoid valve, a duckbill valve, a valve having a pressure responsive diaphragm, which opens when a threshold pressure is reached. Fluid transfer valve  33  may be opened by user intervention and/or triggered automatically by pressurized fluid fuel component  22 . In other words, fluid transfer valve  33  acts as an “on/off” switch for triggering the transfer of fluid fuel component  22  to reaction chamber  18 . In this embodiment, a fluid transfer valve  33  is a check valve including a biasing spring  35  pushing a ball  36  against a sealing surface  37 . Preferably, a deformable sealing member  39  such as an O-ring is also included to assure a seal. Shown as overlapped areas in  FIG. 1  are the portions of valve  33  that would be compressed to form a seal. Plug  86 , discussed above, is used in an exemplary method of assembling valve  33 . A channel is formed in the bottom end of housing  13  for fluid transfer conduit  88 . First, spring  35  is inserted in this channel, followed by ball  36  and sealing member  39 . Plug  86  is finally inserted in this channel to compress spring  35  and presses against ball  36  and sealing member  39  to form a seal with valve  33 . Parts of plug  86 , i.e., hole  87  and peripheral channel  86 , connect fluid transfer conduit  88  to conduit  15  to reach liquid fuel component  22 .  
         [0049]     In this embodiment, fluid transfer valve  33  opens when the fluid pressure within reservoir  44  exceeds the pressure of reaction chamber  18  by a predetermined amount. As reservoir  44  is preferably pressurized, this triggering pressure is exceeded immediately upon pressurizing reservoir  44 . To stop fluid transfer valve  33  from opening before fuel gas is desired to be produced, a stopping mechanism (not shown), such as a latch or a pull tab, may be included, so that the first user of fuel supply  10  may start the transfer of fluid fuel component  22  by releasing the stopping mechanism. Alternatively, chamber  18  is pressurized with an inert gas or hydrogen to equalize the pressure across valve  33  within said predetermined amount.  
         [0050]     Fuel conduit  16  is attached to housing  13  as shown by any method known in the art. Optionally, a gas-permeable, liquid impermeable membrane  32  may be affixed over the reaction chamber-facing side of conduit  16 . Membrane  32  limits the amount of liquids or by-products from being transferred out of gas generating apparatus  12  to the fuel cell via fuel conduit  16 . Fillers or foam can be used in combination with membrane  32  to retain liquids or by-products and to reduce clogging. Membrane  32  may be formed from any liquid impermeable, gas permeable material known to one skilled in the art. Such materials can include, but are not limited to, hydrophobic materials having an alkane group. More specific examples include, but are not limited to: polyethylene compositions, polytetrafluoroethylene, polypropylene, polyglactin (VICRY®), lyophilized dura mater, or combinations thereof. Gas permeable member  32  may also comprise a gas permeable/liquid impermeable membrane covering a porous member. Such a membrane  32  may be used in any of the embodiments discussed herein. Valve  34  can be any valve, such as a pressure-triggered valve (a check valve or a duckbill valve) or a pressure-regulating valve or pressure regulator described below. When valve  34  is a pressure-triggered valve (such as valve  33 ), no fuel can be transferred until P 18  reaches a threshold pressure. Valve  34  may be positioned in fuel conduit  16  as shown in  FIG. 1 , or can be located remote from gas-generating device  12 .  
         [0051]     A connection valve or shut-off valve  27  may also be included, preferably in fluid communication with valve  34 . As shown in  FIG. 2A , connection valve  27  is preferably a separable valve having a first valve component  60  and a second valve component  62 . Each valve component  60 ,  62  has an internal seal. Further, first valve component  60  and second valve component  62  are configured to form an intercomponent seal therebetween before being opened. Connection valve  27  is similar to the shut-off valves described in parent &#39;006 application. Connection valve  27  is shaped and dimensioned for transporting gas.  
         [0052]     First valve component  60  includes a housing  61  and housing  61  defines a first flow path  79  through its interior. Disposed within first flow path  79  is a first slidable body  64 . Slidable body  64  is configured to seal first flow path  79  by pressing a sealing surface  69  against a deformable sealing member  70 , such as an O-ring, disposed in first flow path  79  near a shoulder  82  formed by the configuration of first flow path  79 . Slidable body  64  is biased toward shoulder  82  formed on a second end of first valve component  60  to secure the seal formed at sealing surface  69 . Slidable body  64  will remain in this biased position until first valve component  60  and second valve component  62  are engaged. Alternatively, slidable body  64  is made from an elastomeric material to form a seal and sealing member  70  can be omitted.  
         [0053]     An elongated member  65  extends from one end of slidable body  64 , as shown. Elongated member  65  is a needle-like extension that protrudes from housing  61 . Elongated member  65  is preferably covered with a tubular sealing surface  67 . A space or void is formed in the annular space between elongated member  65  and tubular sealing surface  67  to extend first flow path  79  outside of housing  61 . Tubular sealing surface  67  is connected to elongated member  65  with optional spacers or ribs (not shown) so as not to close off first flow path  79 . Elongated member  65  and tubular sealing surface  67  are configured to be inserted into second valve component  62 .  
         [0054]     Second valve component  62  is similar to first valve component  60  and includes a housing  63  made of a substantially rigid material. Housing  63  defines a second flow path  80  through its interior. Disposed within second flow path  80  is a second slidable body  74 . Slidable body  74  is configured to seal second flow path  80  by pressing a sealing surface  75  against a deformable sealing member  73  near a shoulder  83 . Slidable body  74  is biased to the sealing position by spring  76 . Second valve component  62  thus remains sealed until first valve component  60  and second valve component  62  are correctly connected. Alternatively, slidable body  74  is made from an elastomeric material to form a seal and sealing member  73  can be omitted.  
         [0055]     A pin  81  extends from the other end of slidable body  74 . Pin  81  is a needle-like extension and remains within housing  63 , and does not seal second flow path  80 . Pin  81  is also sized and dimensioned to engage with elongated member  65  when first valve component  60  and second valve component  62  are engaged. A sealing member  71 , such as an O-ring, may be positioned between pin  81  and the interface end of second valve component  62  so that a seal is formed around tubular sealing surface  67  before and during the period when first valve component  60  and second valve component  62  are engaged.  
         [0056]     To open first valve component  60  and second valve component  62  to form a single flow path therethrough, first valve component  60  is inserted into second valve component  62  or vice versa. As the two valve components  60 ,  62  are pushed together, elongated member  65  engages with pin  81 , which press against each other to move first slidable body  64  away from shoulder  82  and second slidable body  74  away from shoulder  83 . As such, sealing members  70  and  73  are disengaged to allow fluid to flow through first flow path  79  and second flow path  80 , as shown in  FIG. 2B .  
         [0057]     First valve component  60  and second valve component  62  are configured such that an inter-component seal is formed between tubular sealing surface  67  and sealing member  71 , before preferably either sealing surface  69  of first slidable body  64  or sealing surface  75  of second slidable body  74  are disengaged from sealing members  70  and  73 , respectively.  
         [0058]     A first end of housing  61  and a second end of housing  63  preferably include barbs  92  and  87 , respectively, for easy and secure insertion into fuel conduit  16 . Alternatively, barbs  92 ,  87  may be any secure connector known in the art, such as threaded connectors or press fit connectors. Additional configurations for connection valves are more fully described in the parent &#39;006 application, also published as U.S. Pat. App. Pub. US 2005/0022883 A1, previously incorporated by reference.  
         [0059]     Retainer  77  is positioned on the interface end of second valve component  62 . Retainer  77  may also be a sealing member, such as an O-ring, a gasket, a viscous gel, or the like. Retainer/sealing member  77  is configured to engage front sealing surface  78  on first valve component  60  to provide another inter-component seal.  
         [0060]     One of valve components  60  and  62  can be integrated with a fuel supply, and the other valve component can be connected to a fuel cell or a device powered by the fuel cell. Either valve component  60  and/or  62  can also be integrated with a flow or pressure regulator or pressure-regulating valve, discussed below.  
         [0061]     Before the first use, fluid transfer valve  33 , as shown in  FIG. 1 , is opened either by removing a pull tab or latch or by removing the initial pressurized gas in chamber  18 . Pressurized fluid fuel component  22  is transferred into reaction chamber  18  via fluid transfer conduit  88  to react with solid fuel component  24 . Pressurized fluid fuel component  22  passes through an orifice  15  and into fluid transfer conduit  88 . While fluid transfer valve  33  is opened, fluid fuel component  22  is continually fed into reaction chamber  18  to create the fuel gas that is then transferred to the fuel cell or the device through fuel conduit  16 . In one embodiment, to halt the production of additional gas, fluid transfer valve  33  can be manually shut-off.  
         [0062]     In another embodiment, one of several pressure-regulating devices may be employed within gas-generating apparatus  12  to allow for the automatic and dynamic control of gas generation. This is accomplished in general by allowing the reaction chamber pressure P 18  to control the inflow of fluid fuel component  22  using fluid transfer valve  33  and/or one or more pressure-regulating valve  26 , as described below.  
         [0063]     In one embodiment, as shown in  FIG. 3 , pressure-regulating valve  26  is positioned in mount  85  or conduits  17  and generally acts as an inlet port between fluid transfer conduit  88  and fluid dispersion element  89 . Pressure-regulating valve  26  can also be positioned in conduit  88  or conduit  15 . An end of fluid dispersion element  89  is connected to a carrier  99 , which is slidably disposed within mount  85 . Near where fluid transfer conduit  17  terminates, one end of carrier  99  is in contact with a globe seal  93  surrounding a jet  94 . Jet  94  is fluidly connected to conduit  17 , and globe seal  93  is configured to control the fluid connection therebetween. As shown in  FIG. 3 , valve  26  is in an open configuration, so fluid would be able to flow from fluid transfer conduit  88  into jet  94 .  
         [0064]     The other end of carrier  99  is connected to a pressure actuated system including a diaphragm  96  exposed to reaction chamber  18  and reaction chamber pressure P 18 , a spring  95  biasing diaphragm  96  towards reaction chamber  18 , and a support plate  98 . Carrier  99  is engaged with support plate  98 . Diaphragm  96  may be any type of pressure-sensitive diaphragm known in the art, such as a thin rubber, metal or elastomeric sheet. When reaction chamber pressure P 18  increases due to the production of fuel gas, diaphragm  96  tends to deform and expand toward the base of mount  85 , but is held in place by the force F 95  from spring  95 . When reaction chamber pressure P 18  exceeds the biasing force F 95  provided by spring  95 , diaphragm  96  pushes support plate  98  toward the base of mount  85 . As carrier  99  is engaged with support plate  98 , carrier  99  also moves toward the base of mount  85 . This motion deforms globe seal  93  to seal the connection between fluid transfer conduit  88  and jet  94 , thereby cutting off the flow of fluid fuel component  22  into reaction chamber  18 .  
         [0065]     While valve  33  (shown in  FIG. 1 ) is open, the operation of gas-generating apparatus  12  may therefore happen in a dynamic and cyclical fashion to provide on demand fuel to the fuel cell. When valve  33  is initially opened, reaction chamber pressure P 18  is low, so pressure-regulating valve  26  is fully open. Valves  33  and  26  may have substantially similar pressure differentials for opening and closing, and in the preferred embodiment one valve may act as a backup for the other. Alternatively, the opening pressure differentials may be different, i.e., the differential pressure to open or close valve  33  may be higher or lower than that of valve  26 , to provide additional ways to control the flow through conduit  88 .  
         [0066]     As fluid fuel component  22  is fed into reaction chamber via valve  26  and/or valve  33  and fluid dispersal elements  89 , the reaction between fluid fuel component  22  and solid fuel component  24  begins to generate fuel gas. Reaction chamber pressure P 18  gradually increases with the build up of fuel gas until threshold pressure P 34  is reached and valve  34  opens to allow the flow of gas through fuel conduit  16 . Fuel gas is then transferred out of reaction chamber  18 . While this process may reach a steady state, the production of gas may outpace the transfer of gas through valve  34 , or, alternatively, valve  34  or another downstream valve may be manually closed by a user or electronically closed by the fuel cell or host device. In such a situation, reaction chamber pressure P 18  may continue to build until reaction chamber pressure P 18  exceeds the force F 95  supplied by spring  95 . At this point, diaphragm  96  deforms toward the base of mount  85 , thereby driving carrier  99  toward the base of mount  85 . As described above, this action causes globe seal  93  to seal the connection between fluid transfer conduit  88  and jet  94 . As no additional fluid fuel component  22  may be introduced into reaction chamber  18 , the production of fuel gas slows and eventually stops. Valve  33  can also be closed by P 18 , i.e., when P 18  exceeds P 44  or when the difference between P 18  and P 44  is less than a predetermined amount, e.g., the amount of force exerted by spring  35 .  
         [0067]     If valve  34  is still open, or if it is re-opened, fuel gas is then transferred out of reaction chamber  18 , so that reaction chamber pressure P 18  decreases. Eventually, reaction chamber pressure P 18  decreases below the force F 95  provided by spring  95 , which pushes support  98  toward reaction chamber  18 . As support  98  is engaged with carrier  99 , carrier  99  also slides toward reaction chamber  18 , which allows globe seal  93  to return to its unsealed configuration. Consequently, additional fluid fuel component  22  begins to flow through jet  94  and into reaction chamber via fluid dispersal element  89 . New fuel gas is produced, and reaction chamber pressure P 18  rises once again. Similarly, when P 18  is less than P 44 , or is less than P 44  by a predetermined amount, then valve  33  opens to allow fluid fuel component  22  to flow.  
         [0068]     This dynamic operation is summarized below in Table 1, when valve  33  is opened manually, or when valve  33  and valve  26  have substantially the same differential triggering pressure so that one valve backs up the other valve.  
                             TABLE 1                           Pressure Cycle of Gas-Generating Apparatus with Valve 33 Open       or Omitted                    State of Gas               Production, Pressure           Condition of Pressure-   in Reaction Chamber       Pressure Balance   regulating Valve 26   18               P 44  &gt; P 18     OPEN   Gas production starts;       F 95  &gt; P 18         Pressure builds       P 18  &lt; P 34         P 44  ≧ P 18     OPEN   Gas production       F 95  ≧ P 18         continues; Pressure       P 18  = P 34         builds if production               outpaces outflow       P 44  ≦ P 18     CLOSED   Gas production slows       F 95  ≦ P 18         to halt; Pressure       P 18  ≧ P 34         decreases       P 44  &gt; P 18     OPEN   Gas production starts       F 95  &gt; P 18         again       P 18  &lt; P 34                    
 
         [0069]    
       
         
               
             
               
               
               
             
           
               
                 TABLE 2 
               
             
             
               
                   
               
               
                   
               
               
                 Pressure Cycle of Gas-Generating Apparatus with Valve 26 Open 
               
               
                 or Omitted 
               
             
          
           
               
                   
                   
                 State of Gas 
               
               
                   
                   
                 Production, Pressure 
               
               
                   
                 Condition of Pressure- 
                 in Reaction Chamber 
               
               
                 Pressure Balance 
                 regulating Valve 33 
                 18 
               
               
                   
               
               
                 P 44  &gt; P 18   
                 OPEN 
                 Gas production starts; 
               
               
                 P 18  &lt; P 34   
                   
                 Pressure builds 
               
               
                 P 44  ≧ P 18   
                 OPEN 
                 Gas production 
               
               
                 P 18  = P 34   
                   
                 continues; Pressure 
               
               
                   
                   
                 builds if production 
               
               
                   
                   
                 outpaces outflow 
               
               
                 P 44  ≦ P 18   
                 CLOSED 
                 Gas production slows 
               
               
                 P 18  ≧ P 34   
                   
                 to halt; Pressure 
               
               
                   
                   
                 decreases 
               
               
                 P 44  &gt; P 18   
                 OPEN 
                 Gas production starts 
               
               
                 P 18  &lt; P 34   
                   
                 again 
               
               
                   
               
             
          
         
       
     
         [0070]     Referring to  FIGS. 4A and 4B , another suitable pressure regulator or regulating valve  126  is shown. Pressure-regulating valve  126  can be positioned within fluid transfer conduit  88 , similar to the positioning of fluid transfer valve  33  as shown in  FIG. 1 . Pressure-regulating valve  126  is preferably placed in series with fluid transfer valve  33 , or pressure-regulating valve  126  may replace fluid transfer valve  33 . Valve  126  can be used with other cartridges or hydrogen generators and can act as a pressure regulator. In another embodiment, regulating valve  126  can replace valve  34 . Regulating valve  126  can be connected to or be a part of the fuel cell or the device that houses the fuel cell. Regulating valve  126  can be located either upstream or downstream of valve components  60  and  62  of connection or shut-off valve  27 .  
         [0071]     Similar to pressure-regulating valve  26 , discussed above, pressure-regulating valve  126  includes a pressure sensitive diaphragm  140 . Diaphragm  140  is similar to diaphragm  96  described above. In this embodiment, however, diaphragm  140  is sandwiched between two housing elements, a valve housing  146  and a valve cover  148 , and has a hole  149  formed through its center, as best seen in  FIG. 4A . Additionally, a void  129  is formed at the interface of valve housing  146  and valve cover  148  to allow diaphragm  140  to move or flex due to the pressure difference between the inlet pressure at channel  143 , the outlet pressure at channel  145 , and a reference pressure, Pref. Valve housing  146  has an internal configuration that defines a flow path through regulator valve  126 . Specifically, channels  143  and  145  are formed in valve housing  146 , where channel  143  is exposed to the inlet pressure and channel  145  is exposed to the outlet pressure. Further, a vent channel  141  is formed in valve cover  148  so that diaphragm  140  is exposed to the reference pressure, which may be atmospheric pressure.  
         [0072]     Valve housing channel  143  is configured to slidingly receive a valve stem  142 . Valve housing channel  143  is configured to narrow at or near the interface of valve housing  146  and valve cover  148  to form a shoulder  137 . Valve stem  142  is preferably a unitary element having a slender stem portion  138  and a cap  131 . This configuration allows slender stem portion  138  to extend through the narrow portion of valve housing channel  143  while cap  131  comes to rest against shoulder  137 . As such, cap  131  and shoulder  137  both include sealing surfaces to close the flow path through valve  126  at shoulder  137  when cap  131  is seated thereagainst. Additionally, a grommet  147  secures valve stem  142  within hole  149  in diaphragm  140 , thereby creating a seal and a secure connection between diaphragm  140  and valve stem  142 . Therefore, as diaphragm  140  moves, valve stem  142  also moves such that cap  131  is seated and unseated against shoulder  137  thereby opening and closing valve  126 .  
         [0073]     When pressure-regulating valve  126  is positioned in conduit  88  of gas-generating apparatus  12 , reaction chamber pressure P 18  provides the outlet pressure at channel  145  and reservoir pressure P 44  provides the inlet pressure at channel  143 . When reaction chamber pressure P 18  is low, valve  126  is in an open configuration as shown in  FIG. 4A , where diaphragm is unflexed and cap  131  of valve stem  142  is unseated from shoulder  137 . As such, fluid fuel component  22  (shown in  FIG. 1 ) flows through valve  126  and into fluid dispersal element  89  (shown in  FIG. 1 ), assuming that fluid transfer valve  33  is also open. The introduction of fluid fuel component  22  to solid fuel component  24  starts the production of fuel gas, which seeps through solid fuel container  23  (shown in  FIG. 1 ) and into reaction chamber  18 , as described above. Reaction chamber pressure P 18  begins to rise. The pressure within conduit  145  rises with P 18  and translates into void  129 . Reaction chamber pressure P 18  gradually increases with the buildup of fuel gas until threshold pressure P 34  is reached and valve  34  (shown in  FIG. 1 ) opens to allow the flow of gas through fuel conduit  16  (shown in  FIG. 1 ). Fuel gas is then transferred out of reaction chamber  18 . While this process may reach a steady state, the production of gas may outpace the transfer of gas through valve  34 , or, alternatively, valve  34  or valve  27  may be manually or electronically closed. In such a situation, reaction chamber pressure P 18  may continue to build until reaction chamber pressure P 18  exceeds P ref , P 44  or (P 44  less P ref ) as no further gas is transferred from reaction chamber  18  with valve  34  (or valves  34 ,  27 ) closed. As a result of the rising reaction chamber pressure P 18 , diaphragm  140  deforms toward valve cover  148 . If reaction chamber pressure P 18  continues to rise, diaphragm  140  deforms toward valve cover  148  to such an extent that cap  131  of valve stem  142  seats against shoulder  137  to seal valve  126 . As such, the flow of additional fluid fuel component is halted, which slows and eventually stops the production of fuel gas in reaction chamber  18 .  
         [0074]     If valve  34  remains open, fuel gas is transferred out of reaction chamber  18 , which reduces the reaction chamber pressure P 18 . This reduction in reaction chamber pressure P 18  is transferred to void  129  by conduit  145 , and diaphragm  140  starts to return to its original configuration as the pressure differential thereacross begins to equalize, i.e., P 18 , P 44  and P ref  begin to balance. As diaphragm  140  moves back into position, valve stem  142  is also moved, thereby unseating cap  131  from shoulder  137  to re-open valve  126 . As such, fluid fuel component  22  is free to once again flow into reaction chamber  18 . This cycle, which is similar to the cycle described in Table 1, repeats until fluid transfer valve  33 , fuel transfer valve  34 , or another downstream valve is closed by the operator or controller.  
         [0075]     The pressure at which regulator/valve  126  opens or closes can be adjusted by adjusting the length of the valve stem or the gap that cap  131  travels between the open and closed position and/or by adjusting Pref. Stem  138  is sized and dimensioned to be movable relative to grommet  147  to adjust length of stem  138 . The longer the length of stem  138  between grommet  147  and cap  131 , the higher the pressure needed to close valve  126 .  
         [0076]     In the embodiment where pressure-regulating valve  126  is located downstream of reaction chamber  18 , e.g., when valve  126  replaces valve  34  or when valve  126  is connected to the fuel cell or the device that houses the fuel cell, P 18  becomes the inlet pressure at channel  143  and the outlet pressure at channel  145  is the pressure of the hydrogen fuel gas that the fuel cell would receive. Preferably, the outlet pressure is substantially constant or is kept within an acceptable range, and the reference pressure, P ref , is selected or adjusted to provide such an outlet pressure. In other words, P ref  is set so that when the inlet pressure exceeds a predetermined amount, diaphragm  140  closes to minimize high or fluctuating outlet pressure at channel  145 .  
         [0077]     Another embodiment of a pressure-regulating valve  226  is shown in  FIGS. 4C and 4D . Pressure-regulating valve  226  is similar to pressure-regulating valve  126  discussed above, as a valve housing  248  is attached to a valve cap  247 . Formed in valve cap  247  is an inlet  243 , while a pressure regulated outlet  245  is formed in valve housing  248 . A hole  251  is formed in a lower portion of valve cap  247 . Preferably, hole  251  is slightly off-center from the longitudinal axis of pressure-regulating valve  226 .  
         [0078]     Sandwiched and retained between valve cap  247  and valve housing  248  is a deformable capped cylinder  250 . Capped cylinder  250  includes an upper end  259 , a lower end  287 , and a hole or channel  201  formed therethrough. Capped cylinder  250  is made of any deformable, elastomeric material known in the art, such as rubber, urethane, or silicone. Capped cylinder  250  functions similar to a pressure-sensitive diaphragm.  
         [0079]     Upper end  259  is positioned adjacent valve cap  247  such that when no fluid flows through pressure-regulating valve  226  upper end  259  is flush against a lower surface of valve cap  247 . The edges of upper end  259  are fixed in position so that even if the remainder of upper cap  259  flexes, the edges remain stationary and sealed.  
         [0080]     Lower end  287  is positioned adjacent valve housing  248 . A void  202  is formed in valve housing  248  and is positioned directly below lower end  287  to allow lower end  287  to flex freely. Preferably, lower end  287  has a different diameter than upper end  259 , as explained below.  
         [0081]     A retainer  253  made of a substantially rigid material surrounds capped cylinder  250 . Retainer  253  defines a hole  241  to connect a second void  203  formed circumferentially between capped cylinder  250  and retainer  253  with a reference pressure Pref. Portion  205  of second void  203  is configured to extend partially along and on top of lower cap  287 .  
         [0082]     To regulate pressure, inlet gas or liquid enters pressure-regulating valve through inlet  243  and passes into hole  251 . Hole  251  can be a circular channel or ring defined on cap  247 . Upper end  259  seals hole  251  until the pressure exerted by the inlet gas or liquid from inlet  243  reaches a threshold to deform upper end  259 . When the gas deforms upper end  259 , the deformation translates through the body of cylinder  250  to also deform lower end  287 . Once upper end  259  deforms, the gas is able to pass through hole  251 , through capped cylinder  250  and out regulated outlet  245 .  
         [0083]     Since the applied forces on capped cylinder  250  are the products of the applied pressure times the area exposed to that pressure, the forces acting on capped cylinder  250  can be summarized as follows: 
 
Inlet Force+Reference         Force Outlet Force (P at inlet  243 ·Area of upper end  259 )+(Pref·Area of portion  205 )         (P at outlet  245 ·Area of lower end  287 ) 
 
 When the outlet force is greater than the inlet and reference forces, then pressure-regulating valve  226  is closed, and when outlet force is less than the inlet and reference forces, the valve  226  is open. Since, in this embodiment the outlet force has to counter-balance both the inlet and reference forces, the area of lower end  287  is advantageously made larger than the area of upper end  259 , as shown, so that the outlet force may be larger without increasing the outlet pressure. By varying the areas of ends  259  and  287  and portion  205 , the balance of forces on capped cylinder  250  can be controlled and the pressure differential required to open and close valve  226  can be determined. 
 
         [0084]     Since reference pressure P ref  tends to press down on lower end  287 , this additional pressure can lower the threshold pressure to initiate flow, i.e., reference pressure P ref  is relatively high to assist the gas in deforming capped cylinder  250 . Reference pressure P ref  may be adjusted higher or lower to further regulate the pressure of the gas leaving outlet  245 .  
         [0085]     FIGS.  5 A-D shows a combination of a pressure-regulating valve  326  being used with connection or shut-off valve  27 .  FIG. 5A  shows pressure-regulating valve  326  being mated to be in fluid communication with valve component  60  of connection valve  27 . Pressure-regulating valve  326  is similar to pressure-regulating valves  126  and  226  described above, and has a spring-biased diaphragm  340 . Diaphragm  340  is supported by first piston  305 , which is being biased by spring  306  toward second piston  307 . First piston  305  is opposed by second piston  307  biased by spring  309 , which biases piston  307  toward piston  305 . A ball  311  is disposed between spring  309  and second piston  307 .  
         [0086]     Springs  306  and  309  oppose each other, and, by balancing the forces exerted by the two springs, the outlet pressure at channel  313  can be determined. Spring  309  does not act on or have any effect on spring  66  of valve component  60 . When valve component  60  is opened by mating with valve component  62 , shown in  FIGS. 5B-5D , hydrogen fuel gas or other fluids flows through valve component  60  and to inlet  315 . If the fluid is hydrogen gas, then the hydrogen is transported to the fuel cell. A flow path through valve  326  is established from inlet  315  through spring  309 , around ball  311 , through the space between piston  307  and shoulder  337  of housing  346 , though orifice  337  of housing  346 , and through orifice  348  and outlet  313 . In this embodiment, the space between piston  307  and shoulder  337  is normally open to allow fluid to pass therethrough.  
         [0087]     The pressure of the incoming fluid through inlet  315  or the pressure at outlet  313 , if sufficiently high, may overcome the resultant force between springs  306  and  309  and move diaphragm  340  and pistons  305  and  307  to the left as depicted in  FIG. 5A . Spring  309  then biases ball  311  to sealing member  319  to seal valve  326 . To ensure that the flow of fuel follows the preferred path, sealing member  317  may be provided.  
         [0088]     In one embodiment, the force applied on diaphragm  340  and pistons  305  and  307  can be adjusted. Spring  306  is adjustable by a rotational adjusting member  320 , which is secured by a threaded lock nut  321 . Rotating adjusting member  321  in one direction further compresses spring  306  to increase the force applied on the diaphragm and pistons, and rotating in the opposite direction expands spring  306  to decrease the force applied on the diaphragm and pistons. Additionally, a reference pressure, P ref , can be applied to channel  323  behind piston  305  to apply another force on piston  305 .  
         [0089]      FIG. 5B  shows pressure regulator/valve  326  connected to valve component  60  with valve component  62  not connected to valve component  60 .  FIG. 5C  shows regulator/valve  326  with valve components  60  and  62  partially engaged, but with no flow path established through valve components  60  and  62 .  FIG. 5D  shows regulator/valve  326  with valve components  60  and  62  fully engaged with a flow path established through valve components  60  and  62 . In one embodiment, valve component  62  may be connected to conduit  16  of gas-generating apparatus  12 , shown in  FIG. 1 , and regulator  326  replaces valve  34  and is connected to the fuel cell or the device. On the other hand, valve component  62  may be connected to the fuel cell or the device and regulator  326  and valve component  60  are connected to the gas-generating apparatus or fuel supply. If a high pressure surges through valve  326 , diaphragm  340  limits the amount of fuel that can be transported through conduit  313 .  
         [0090]     Another embodiment of a pressure-regulating valve  426  is shown in  FIGS. 6A  and B. Pressure-regulating valve  426  is similar to pressure-regulating valve  226 , discussed above, except that valve  426  has a slidable piston  450  instead of flexible capped cylinder  350 . Valve  426  has valve housing  448  attached to a valve cap  447 . Formed in valve cap  447  is an inlet  443 , while a pressure regulated outlet  445  is formed in valve housing  448 . A hole  451  is formed in a lower portion of valve cap  447 . Preferably, hole  451  is slightly off-center from the longitudinal axis of pressure-regulating valve  426 . Hole  451  may comprise a plurality of holes formed as a ring so that the inlet pressure is applied uniformly on slidable piston  450 .  
         [0091]     Slidably disposed between valve cap  447  and valve housing  448  is a slidable piston  450 . Slidable piston  450  includes an upper portion  459  having a first diameter, a lower portion  487  having a second diameter which is preferably larger than the diameter of upper portion  459 , and a hole  401  formed therethrough. Slidable piston  450  is made of any rigid material known in the art, such as plastic, elastomer, aluminum, a combination of elastomer and a rigid material or the like.  
         [0092]     A space  402  is formed in valve housing  448  to allow piston  450  to slide between cap  447  and housing  448 . A second void  403  is formed between slidable piston  450  and valve housing  448 . Void  403  is connected with a reference pressure Pref. A portion  405  of void  403  is positioned opposite to lower end  487 , so that a reference force can be applied on piston  450 .  
         [0093]     Upper portion  459  is positioned adjacent valve cap  447  such that when the outlet force exceeds the inlet force and the reference force, as discussed above, upper portion  459  is flush against a lower surface of valve cap  447  to close valve  426 , as shown in  FIG. 6A . When the outlet force is less than the inlet and reference forces, piston  450  is pushed toward housing  448  to allow fluids, such as hydrogen gas, to flow from inlet  443  through hole(s)  451  and hole  401  to outlet  445 . Again, as discussed above with reference to valve  226 , the surface areas of ends  459  and  487 , and of space  405  can be varied to control the opening and closing of valve  426 .  
         [0094]     As will be recognized by those in the art, any of these valves may be used, either alone or in combination, to provide pressure-based regulation of gas-generating apparatus  12 . For example, valve  126 ,  226 ,  326  or  426  can be used in place of valve  26 ,  33  or  34 .  
         [0095]     In accordance to another aspect of the present invention, a pre-selected orifice is provided in conjunction with valve  126 ,  226 ,  326  and/or  426  to regulate the pressure or volume of the fluid, e.g., hydrogen gas, exiting from the outlet of these valves. For example, referring to valve  326 , shown in  FIG. 5A , orifice  348  is positioned upstream of outlet  313 . In one aspect, orifice  326  acts as a flow restrictor to ensure that when the inlet pressure at inlet  315  or within pressure-regulating valve  326  is high, orifice  348  sufficiently limits the outlet flow at  313  so that the high pressure can act on diaphragm  340 , moving it to the left, to close valve  326 . An advantage of using flow restrictor/orifice  348  is when outlet  313  is open to a low pressure, e.g., atmospheric pressure, or open to a chamber that cannot hold pressure orifice  348  helps ensure that diaphragm  340  would sense the inlet pressure.  
         [0096]     Orifice  348  may also control the flow of fluid out of outlet  313 . When the range of inlet pressure at inlet  315  or pressure internal to pressure-regulating valve  326  is known and the desirable flow rate is also known, by applying flow equations for compressible fluid flow, such as Bernoulli&#39;s equations (or using incompressible fluid flow equations as a close approximation thereof) the diameter(s) of orifice  348  can be determined.  
         [0097]     Additionally, the diameter of effective diameter of orifice  348  may vary according to inlet pressure at inlet  315  or internal pressure of valve  326 . One such variable orifice is described in commonly owned, co-pending U.S. Publ. Appl. No. US 2005/0118468, which is incorporated herein by reference in its entirety. The &#39;468 reference discloses valve ( 252 ) shown in FIGS.  6 ( a )-( d ) and  7 ( a )-( k ) and corresponding texts of that reference. The various embodiments of this valve ( 252 ) have reduced effective diameter when flow pressure is high and have increased effective diameter when the flow pressure is lower.  
         [0098]     Another variable orifice  348  is shown in  FIGS. 7A and 7B . In this embodiment, orifice  348  or another fluid conduit has a duckbill valve  350  disposed therein with nozzle  352  facing the direction of fluid flow, as shown. The fluid&#39;s pressure acts on neck  354  and when the pressure is relatively low the diameter of nozzle  352  is relatively large, and when the pressure is relatively high the diameter of nozzle  352  is relatively small to further restrict flow. When pressure is sufficiently high, nozzle  352  may be shut off.  
         [0099]     Some examples of the fuels that are used in the present invention include, but are not limited to, hydrides of elements of Groups IA-IVA of the Periodic Table of the Elements and mixtures thereof, such as alkaline or alkali metal hydrides, or mixtures thereof. Other compounds, such as alkali metal-aluminum hydrides (alanates) and alkali metal borohydrides may also be employed. More specific examples of metal hydrides include, but are not limited to, lithium hydride, lithium aluminum hydride, lithium borohydride, sodium hydride, sodium borohydride, potassium hydride, potassium borohydride, magnesium hydride, calcium hydride, and salts and/or derivatives thereof. The preferred hydrides are sodium borohydride, magnesium borohydride, lithium borohydride, and potassium borohydride. Preferably, the hydrogen-bearing fuel comprises the solid form of NaBH 4 , Mg(BH 4 ) 2 , or methanol clathrate compound (MCC) which is a solid and includes methanol. In solid form, NaBH 4  does not hydrolyze in the absence of water and therefore improves shelf life of the cartridge. However, the aqueous form of hydrogen-bearing fuel, such as aqueous NaBH 4 , can also be utilized in the present invention. When an aqueous form of NaBH 4  is utilized, the chamber containing the aqueous NaBH 4  also includes a stabilizer. Exemplary stabilizers can include, but are not limited to, metals and metal hydroxides, such as alkali metal hydroxides. Examples of such stabilizers are described in U.S. Pat. No. 6,683,025, which is incorporated by reference herein in its entirety. Preferably, the stabilizer is NaOH.  
         [0100]     The solid form of the hydrogen-bearing fuel is preferred over the liquid form. In general, solid fuels are more advantageous than liquid fuels because the liquid fuels contain proportionally less energy than the solid fuels and the liquid fuels are less stable than the counterpart solid fuels. Accordingly, the most preferred fuel for the present invention is powdered or agglomerated powder sodium borohydride.  
         [0101]     According to the present invention, the fluid fuel component preferably is capable of reacting with a hydrogen-bearing solid fuel component in the presence of an optional catalyst to generate hydrogen. Preferably, the fluid fuel component includes, but is not limited to, water, alcohols, and/or dilute acids. The most common source of fluid fuel component is water. As indicated above and in the formulation below, water may react with a hydrogen-bearing fuel, such as NaBH 4  in the presence of an optional catalyst to generate hydrogen. 
 
X(BH 4 ) y +2H 2 O→X(BO) 2 +4H 2  
 
 Where X includes, but is not limited to, Na, Mg, Li and all alkaline metals, and y is an integer. 
 
         [0102]     Fluid fuel component also includes optional additives that reduce or increase the pH of the solution. The pH of fluid fuel component can be used to determine the speed at which hydrogen is produced. For example, additives that reduce the pH of fluid fuel component result in a higher rate of hydrogen generation. Such additives include, but are not limited to, acids, such as acetic acid and sulfuric acid. Conversely, additives that raise the pH can lower the reaction rate to the point where almost no hydrogen evolves. The solution of the present invention can have any pH value less than 7, such as a pH of from about 1 to about 6 and, preferably, from about 3 to about 5.  
         [0103]     In some exemplary embodiments, fluid fuel component includes a catalyst that can initiate and/or facilitate the production of hydrogen gas by increasing the rate at which fluid fuel component reacts with a fuel component. The catalyst of these exemplary embodiments includes any shape or size that is capable of promoting the desired reaction. For example, the catalyst may be small enough to form a powder or it may be as large as the reaction chamber, depending on the desired surface area of the catalyst. In some exemplary embodiments, the catalyst is a catalyst bed. The catalyst may be located inside the reaction chamber or proximate to the reaction chamber, as long as at least one of either fluid fuel component or the solid fuel component comes into contact with the catalyst.  
         [0104]     The catalyst of the present invention may include one or more transitional metals from Group VIIIB of the Periodic Table of Elements. For example, the catalyst may include transitional metals such as iron (Fe), cobalt (Co), nickel (Ni), ruthenium (Ru), rhodium (Rh), platinum (Pt), palladium (Pd), osmium (Os) and iridium (Ir). Additionally, transitional metals in Group IB, i.e., copper (Cu), silver (Ag) and gold (Au), and in Group IIB, i.e., zinc (Zn), cadmium (Cd) and mercury (Hg), may also be used in the catalyst of the present invention. The catalyst may also include other transitional metals including, but not limited to, scandium (Sc), titanium (Ti), vanadium (V), chromium (Cr) and manganese (Mn). Transition metal catalysts useful in the present invention are described in U.S. Pat. No. 5,804,329, which is incorporated by reference herein in its entirety. The preferred catalyst of the present invention is CoCl 2 .  
         [0105]     Some of the catalysts of the present invention can generically be defined by the following formula: 
 
M a X b  
 
         [0106]     wherein M is the cation of the transition metal, X is the anion, and “a” and “b” are integers from 1 to 6 as needed to balance the charges of the transition metal complex.  
         [0107]     Suitable cations of the transitional metals include, but are not limited to, iron (II) (Fe 2+ ), iron (III) (Fe 3+ ), cobalt (Co 2+ ), nickel (II) (Ni 2+ ), nickel (III) (Ni 3+ ), ruthenium (III) (Ru 3+ ), ruthenium (IV) (Ru 4+ ), ruthenium (V) (Ru 5+ ), ruthenium (VI) (Ru 6+ ), ruthenium (VIII) (Ru 8+ ), rhodium (III) (Rh 3+ ), rhodium (IV) (Rh 4+ ), rhodium (VI) (Rh 6+ ), palladium (Pd 2+ ), osmium (III) (Os 3+ ), osmium (IV) (Os 4+ ), osmium (V) (Os 5+ ), osmium (VI) (Os 6+ ), osmium (VIII) (OS 8+ ), iridium (III) (Ir 3+ ), iridium (IV) (Ir 4+ ), iridium (VI) (Ir 6+ ), platinum (II) (Pt 2+ ), platinum (III) (Pt 3+ ), platinum (IV) (Pt 4+ ), platinum (VI) (Pt 6+ ), copper (I) (Cu + ), copper (II) (Cu 2+ ), silver (I) (Ag + ), silver (II) (Ag 2+ ), gold (I) (Au + ), gold (III) (Au 3+ ), zinc (Zn 2+ ), cadmium (Cd 2+ ), mercury (I) (Hg + ), mercury (II) (Hg 2+ ), and the like.  
         [0108]     Suitable anions include, but are not limited to, hydride (H − ), fluoride (F − ), chloride (Cl − ), bromide (Br − ), iodide (I − ), oxide (O 2− ), sulfide (S 2− ), nitride (N 3− ), phosphide (P 4− ), hypochlorite (ClO − ), chlorite (ClO 2   − ), chlorate (ClO 3   − ), perchlorate (ClO 4   − ), sulfite (SO 3   2− ), sulfate (SO 4   2− ), hydrogen sulfate (HSO 4   − ), hydroxide (OH − ), cyanide (CN − ), thiocyanate (SCN − ), cyanate (OCN − ), peroxide (O 2   2− ), manganate (MnO 4   2− ), permanganate (MnO 4   − ), dichromate (Cr 2 O 7   2− ), carbonate (CO 3   2− ), hydrogen carbonate (HCO 3   − ), phosphate (PO 4   2− ), hydrogen phosphate (HPO 4   − ), dihydrogen phosphate (H 2 PO 4   − ), aluminate (Al 2 O 4   2− ), arsenate (AsO 4   3− ), nitrate (NO 3   − ), acetate (CH 3 COO − ), oxalate (C 2 O 4   2− ), and the like. A preferred catalyst is cobalt chloride.  
         [0109]     In some exemplary embodiments, the optional additive, which is in fluid fuel component and/or in the reaction chamber, is any composition that is capable of substantially preventing the freezing of or reducing the freezing point of fluid fuel component and/or solid fuel component. In some exemplary embodiments, the additive can be an alcohol-based composition, such as an anti-freezing agent. Preferably, the additive of the present invention is CH 3 OH. However, as stated above, any additive capable of reducing the freezing point of fluid fuel component and/or solid fuel component may be used.  
         [0110]     Other embodiments of the present invention will be apparent to those skilled in the art from consideration of the present specification and practice of the present invention disclosed herein. For example, any of the valves herein may be triggered by an electronic controller such as a microprocessor. A component of one valve can be used with another valve. Also, a pump may be included to pump the fluid fuel component into the reaction chamber. It is intended that the present specification and examples be considered as exemplary only with a true scope and spirit of the invention being indicated by the following claims and equivalents thereof.