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Title:
A PORTABLE FUEL CELL APPARATUS AND SYSTEM
Document Type and Number:
WIPO Patent Application WO/2019/156631
Kind Code:
A1
Abstract:
The present invention describes a portable proton exchange membrane fuel cell (PEMFC) system and apparatus to generate electric power, which is suited to be carried in a pouch. The PEMFC system provides several safety and protective features when the PEMFC system or apparatus is portable and carried by a user. The PEMFC system or apparatus comprises a cooling coil disposed in the water storage vessel to cool the generated hydrogen gas to a predetermined temperature, a buffer tank is disposed downstream of the cooling coil, so that the condensed water collected in the buffer tank is recycled back into the water storage vessel via a recollection solenoid valve. The system or apparatus further comprises a check valve disposed in a discharge line connecting the water pump to the reactor vessel, wherein the discharge line comprises a tubing with a predetermined rupture pressure range to provide a non-recoverable fail-safe mechanism for the system or apparatus.

Inventors:
YAP, De Tao, Francis (Block 265, Toh Guan Road#07-19, Singapore 5, 600265, SG)
TAY, Han Chong, Shaun (Block 155, Gangsa Road#20-339, Singapore 5, 670155, SG)
HO, Fook Heng (23 Marina Way, #09-33, Singapore 9, 589641, SG)
AW, Cheng Hok (4 Geylang Lorong 37, #04-04, Singapore 2, 387902, SG)
Application Number:
SG2019/050070
Publication Date:
August 15, 2019
Filing Date:
February 07, 2019
Export Citation:
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Assignee:
ADVANCED MATERIAL ENGINEERING PTE LTD (249 Jalan Boon Lay, Singapore 3, 619523, SG)
International Classes:
H01M8/065; C01B3/06; H01M8/22
Domestic Patent References:
WO2017127022A12017-07-27
Foreign References:
US20170054175A12017-02-23
US20100247426A12010-09-30
US20170018789A12017-01-19
CN206599440U2017-10-31
Attorney, Agent or Firm:
TAY, Yeo King (300 Beach Road, #31-04/05 The Concourse, Singapore 5, 199555, SG)
Download PDF:
Claims:
CLAIMS:

1. A portable hydrogen proton exchange membrane fuel cell (PEMFC) apparatus comprising a housing enclosing:

a proton exchange membrane fuel cell (PEMFC);

a water storage vessel;

a hydride powder disposed in a reactor vessel;

a water pump disposed to supply water from the water storage vessel to the reactor vessel; and

a check valve disposed in a discharge line connecting the water pump to the reactor vessel, wherein the discharge line comprises a tubing with a predetermined rupture pressure range.

2. The portable PEMFC apparatus according to claim 1, further comprising a cooling coil disposed in the water storage vessel to cool down hydrogen gas generated from hydrolysis of the hydride powder in the reactor vessel.

3. The portable PEMFC apparatus according to claim 1 or 2, wherein a mouth of the water storage vessel is removeably sealed with a porous membrane, which porous membrane is permeable to gas, so that the water storage vessel is spill-proof and the interior is at atmospheric pressure.

4. The portable PEMFC apparatus according to any one of claims 1-3, wherein a weighted clunk is attached to an end of a water intake tube that connects to the water pump, so that the end of the water tube is kept submerged under water.

5. The portable PEMFC apparatus according to any one of claims 2-4, further comprising a buffer tank and a recollection valve, wherein the buffer tank is in fluid communication with the cooling coil and the recollection valve is operable to recycle water condensed in the buffer tank (caused by cooling of the hydrogen gas) into the water storage vessel.

6. The portable PEMFC apparatus according to claim 5, further comprising a purifying filter disposed in fluid communication with the buffer tank.

7. The portable PEMFC apparatus according to claim 6, further comprising a supply valve disposed in fluid communication between the buffer tank and the purifying filter, wherein the supply valve is operable by a solenoid.

8. The portable PEMFC apparatus according to any one of claims 2-7, wherein fluid communication for the hydrogen gas is formed in a manifold.

9. The portable PEMFC apparatus according to claim 8, wherein the manifold further supports the check valve recited in claim 1.

10. The portable PEMFC apparatus according to any one of preceding claims, wherein the reactor vessel has a double-wall construction, which interior of the double-wall is evacuated to a vacuum.

11. The portable PEMFC apparatus according to claim 10, further comprising a vessel cap disposed for closing a mouth of the reactor vessel.

12. The portable PEMFC apparatus according to claim 11, further comprising a mounting plate or a coupling plate disposed on the vessel cap to facilitate quick replacement of the reactor vessel.

13. The portable PEMFC apparatus according to claim 8 or 9, further comprising heat insulation disposed on an exterior of the reactor vessel and vessel cap.

14. The portable PEMFC apparatus according to any one of the preceding claims, further comprising a controller, wherein the controller receives signals from a temperature sensor and a pressure sensor, and in response turns on a battery to supply electric power to a heater disposed in the reactor vessel before voltage generated from the PEMFC apparatus exceeds voltage across the battery.

15. The portable PEMFC apparatus according to claim 14, further comprising an electric outlet port, wherein the electric outlet port is controlled by the controller so that the reactor vessel is hot-swappable when the PEMFC apparatus is operating and power supply at the electric outlet port is not interrupted.

16. The portable PEMFC apparatus according to any one of claims 1-15, further comprising a pouch for carrying the portable PEMFC apparatus by a user.

17. The portable PEMFC apparatus according to claim 16, wherein the pouch comprises some protective foams and EMI shield linings.

18. A portable hydrogen proton exchange membrane fuel cell (PEMFC) system comprising:

connecting a water pump to supply water from a water storage vessel to a reactor vessel, wherein a pump discharge line comprises a tubing with a predetermined rupture pressure range and a check valve;

thermally insulating the reactor vessel with a vacuum double wall and, on an exterior of the reactor vessel, surrounding the reactor vessel with a thermal insulator;

hydrolysing a hydride powder disposed in the reactor vessel with a controlled amount of water supplied through the water pump to generate hydrogen gas on demand; and

directing the hydrogen gas to flow from an outlet of the reactor vessel to a proton exchange fuel membrane cell (PEMFC) to generate electric power.

19. The portable PEMFC system according to claim 18, further comprising:

passing the hydrogen gas through a cooling coil disposed in the water storage vessel to cool the hydrogen gas to a predetermined temperature; and

condensing water vapour in the hydrogen gas in a buffer tank, which buffer tank is disposed downstream of the cooling coil, so that the condensed water collected in the buffer tank is recycled back into the water storage vessel via a recollection solenoid valve.

20. The portable PEMFC system according to claim 19, further comprising:

purifying the hydrogen gas by passing the hydrogen gas through a purifying filter disposed downstream of the buffer tank.

21. The portable PEMFC system according to claim any one of claims 18-20, further regulating operation of the PEMFC with a controller, wherein the controller comprises an algorithm that responds adaptively to a hydrogen utilization level remaining in the hydride powder.

22. The portable PEMFC system according to claim 21, wherein the controller and a battery allow hot-swapping of the reactor vessel when the hydride powder is depleted and the PEMFC system is still operating. 23. A process for operating a proton exchange membrane fuel cell (PEMFC) and for producing electric power to drive an electric load carried on a user, the process comprising: generating hydrogen on demand by supplying an amount of water to hydrolyse a hydride powder disposed in a reactor vessel;

cooling down a temperature of the hydrogen gas produced by passing the hydrogen gas through a cooling coil disposed in a water storage vessel, condensing water vapour from the hydrogen gas, and purifying the hydrogen gas by passing the hydrogen gas through a purifying filter, before supplying the hydrogen gas to a PEMFC;

rupturing the water supply line at a predetermined pressure range, with the water supply line connected to the reactor vessel; and

closing the water supply line with a check valve, so as to maintain leak-proof inside the reaction vessel, and shutting down the reactor vessel in a non-recoverable fail-safe mode when the PEMFC encounters a safety issue.

Description:
A Portable Fuel Cell Apparatus and System

Field of Invention

[001] The present invention relates to a portable fuel cell apparatus and system. In particular, the invention relates to a proton exchange membrane fuel cell (PEMFC) that can be carried around by a person, such as, on a soldier pack.

Background

[002] A micro fuel cell is a good portable power source of electricity because of its high energy density than that of batteries. These fuel cells may be Direct methanol fuel cell (DMFC), solid oxide fuel cell (SOFC) or proton exchange membrane fuel cell (PEMFC). PEMFC is a promising solution because of its excellent performance at low temperatures. A limitation for the use of these fuel cells is the requirement for high-density hydrogen storage.

[003] Kim and Lee, published an article“A complete power source of micro PEM cell with NaBH4 microreactor”, in Micro Electro Mechanical Systems, 2011 IEEE 24 th International Conference. This micro PEM cell includes a micro reactor for hydrogen generation from NaBH4 alkaline solution.

[004] In another approach, Jang, Lee and Kwon, published an article“Design and fabrication of a fully enclosed micro PEM fuel cell using novel glass bipolar plates”, in Researchgate publication no. 268347568. The glass used is photosensitive glass, in which microchannels are formed thereon using photolithography.

[005] In yet another approach, US Patent No. 9,029,034, issued to Altergy Systems, describes an integrated recirculating fuel cell that reduces residence time of the mixed gas condition at the anode during purging; by so doing, it reduces the speed of cathode catalyst degradation caused by high electrical potentials across the fuel cell. [006] As soldiers carry more electronic equipment, it can thus be seen that there exists a need to supply another high energy density, portable hydrogen fuel cell to complement a soldier pack.

Summary

[007] The following presents a simplified summary to provide a basic understanding of the present invention. This summary is not an extensive overview of the invention, and is not intended to identify key features of the invention. Rather, it is to present some of the inventive concepts of this invention in a generalised form as a prelude to the detailed description that is to follow.

[008] The present invention seeks to provide a portable proton exchange membrane fuel cell (PEMFC) to complement a soldier pack. The PEMFC helps to extend mission endurance, to increase mileage and/or to increase payload capacity for manned or unmanned systems deployed in a field. The PEMFC generates electric power on demand from a hydride cartridge; the hydride cartridge is easily replaced and electric power supply is quickly and easily restarted once a new hydride cartridge is inserted into the PEMFC.

[009] In one embodiment, the present invention provides a portable hydrogen proton exchange membrane fuel cell (PEMFC) apparatus comprising a housing enclosing: a proton exchange membrane fuel cell (PEMFC); a water storage vessel; a hydride powder disposed in a reactor vessel; a water pump disposed to supply water from the water storage vessel to the reactor vessel; and a check valve disposed in a discharge line connecting the water pump to the reactor vessel, wherein the discharge line comprises a tubing with a predetermined rupture pressure range.

[0010] Preferably, the apparatus comprises a cooling coil disposed in the water storage vessel to cool down hydrogen gas generated in the reactor vessel. Preferably, a mouth of the water storage vessel is removeably sealed with a porous membrane so that the water storage vessel is spill-proof and the interior remains at atmospheric pressure. The end of the water intake tube has a weighted clunk to keep the end submerged under water. [0011] Preferably, the apparatus comprises a buffer tank and a recollection valve. The recollection valve is operable to recycle water condensed in the buffer tank into the water storage vessel. A hydrogen purifying filter (or IEF) and a supply valve are connected to the buffer tank.

[0012] Preferably, the reactor vessel has a double-walled construction, with the interior of the double-wall being evacuated to a vacuum. The mouth of the reactor vessel is closed with a vessel cap. Preferably, a mounting plate or coupling plate is disposed on the vessel cap to facilitate quick replacement of the reactor vessel. Quick disconnect couplings on the mounting plate or coupling plate, or a mounting manifold allows quick connection or disconnection. The exterior of the reactor vessel, cap and coupling plate is covered by a heat insulator. A pouch is provided to carry the above PEMFC apparatus.

[0013] The apparatus also comprises a battery and a controller; with these, the reactor vessel is hot-swappable without power interruption.

[0014] In another embodiment, the present invention provides a portable hydrogen proton exchange membrane fuel cell (PEMFC) system comprising: connecting a water pump to supply water from a water storage vessel to a reactor vessel, wherein a pump discharge line comprises a tubing with a predetermined rupture pressure range and a check valve; thermally insulating the reactor vessel with a vacuum double wall and, on an exterior of the reactor vessel, surrounding the reactor vessel with a thermal insulator; hydrolysing a hydride powder disposed in the reactor vessel with a controlled amount of water supplied through the water pump to generate hydrogen gas on demand; and directing the hydrogen gas to flow from an outlet of the reactor vessel to a proton exchange fuel membrane cell (PEMFC) to generate electric power.

[0015] Preferably, the system further comprises: passing the hydrogen gas through a cooling coil disposed in the water storage vessel to cool the hydrogen gas to a predetermined temperature; condensing water vapour in the hydrogen gas in a buffer tank, which buffer tank is disposed downstream of the cooling coil, so that the condensed water collected in the buffer tank is recycled back into the water storage vessel via a recollection solenoid valve, and purifying the hydrogen gas by passing the hydrogen gas through a purifying filter disposed downstream of the buffer tank. [0016] The system is regulated by a controller. Preferably, the controller comprises an algorithm that responds adaptively to a hydrogen utilization level remaining in the hydride powder. With the controller, a battery allows hot-swapping of the reactor vessel.

[0017] In yet another embodiment, the present invention provides a process for operating a portable hydrogen proton exchange membrane fuel cell (PEMFC) and for producing electric power to drive an electric load carried on a user. The process comprises: generating hydrogen on demand by supplying an amount of water to hydrolyse a hydride powder disposed in a reactor vessel; cooling down a temperature of the hydrogen gas produced by passing the hydrogen gas through a cooling coil disposed in a water storage vessel, condensing water vapour from the hydrogen gas, and purifying the hydrogen gas by passing the hydrogen gas through a purifying filter, before supplying the hydrogen gas to a PEMFC; rupturing the water supply line at a predetermined pressure range, with the water supply line connected to the reactor vessel; and closing the water supply line with a check valve, so as to maintain leak-proof inside the reaction vessel, and shutting down the reactor vessel in a non-recoverable fail-safe mode when the PEMFC encounters a safety issue.

Brief Description of the Drawings

[0018] This invention will be described by way of non-limiting embodiments of the present invention, with reference to the accompanying drawings, in which:

[0019] FIG. 1A illustrates a schematic system for a hydrogen proton exchange membrane fuel cell (PEMFC), whilst FIG. 1B illustrates the PEMFC apparatus according to an embodiment of the present invention;

[0020] FIG. 2 illustrates an assembly of components constituted in the above PEMFC apparatus;

[0021] FIGs. 3A and 3B illustrate a part of a housing constituted in the above PEMFC apparatus; [0022] FIGs. 4A and 4B illustrate two reactor vessels according to mounting configurations of the present invention; and

[0023] FIGs. 5A-5E illustrate a pouch for carrying the above PEMFC apparatus.

Detailed Description

[0024] One or more specific and alternative embodiments of the present invention will now be described with reference to the attached drawings. It shall be apparent to one skilled in the art, however, that this invention may be practised without such specific details. Some of the details may not be described at length so as not to obscure the invention. For ease of reference, common reference numerals or series of numerals will be used throughout the figures when referring to the same or similar features common to the figures.

[0025] FIG. 1A shows a schematic of a portable hydrogen proton exchange membrane fuel cell (PEMFC) system 100 according to an embodiment of the present invention. The entire PEMFC system 100 is enclosed in a housing 101, which is preferably made from a polymer. Whilst, the PEMFC system 100 is portable and is designed to be carried by a user, for eg. along with a soldier pack 300, the system is not so limited. The following describes such portable PEMFC system 100, which provides a safe, useful and portable power system to the user. As seen from FIG. 1 A, the PEMFC system 100 includes at least a proton-exchange membrane fuel cell 2, a hydrogen generator 3 and an associated controller 110; the hydrogen generator 3 includes a hydrogen reactor vessel 102, an accompanying vessel cap 103 and a water storage vessel 16. The vessel cap 103 closes the hydrogen reactor vessel 102 to provide a leak-proof reaction chamber 10; in one embodiment, the vessel cap 103 is connected to the reactor vessel 102 by welding. In use, a hydride powder 30 is disposed inside the reaction chamber 10, which is hydrolysed with water to produce hydrogen gas. The hydrogen reactor vessel 102 is a double-walled vessel, with the space between the walls being evacuated to a vacuum. The exterior surfaces of the hydrogen reactor vessel 102 and vessel cap 103 are covered by a heat insulator 104, with part of the heat insulator 104 being shown in FIG. 1A. With double-walled vacuum around the reactor vessel 102, a thickness required of the heat insulator 104 is significantly reduced; the reduced bulk of the heat insulator 104 means reduction in the external dimensions of the heat insulator and reduction is weight for this PEMFC system 100. To allow quick replacement of the reactor vessel 102 and vessel cap 103 assembly, a water supply tubing, hydrogen outlet, heater, etc. that enter the reactor vessel 102 are supported on a mounting plate 106. In addition, the water supply tubing may be connected at the mounting plate 106 via a quick-disconnect coupling 11; similarly, the hydrogen outlet may be connected at the mounting plate 106 via another quick-disconnect coupling 13. Hydrogen gas produced in the reactor vessel 102 is then supplied to the fuel cell 2 through a pressure regulator 4 and a hydrogen outlet 5. A gas outlet from the fuel cell 2 is connected to an exhaust port 134 located on a manifold 109; the exhaust port 134 is fluidly connected to a purge valve 136, which is operable to vent out gas from the fuel cell 2; in use, the purge valve 136 is controlled by a signal from the controller 110 via a solenoid S3 on the purge valve 136. The purge valve 136 and all the fluid flow components that will be described for connecting into the manifold 109 are, preferably, of a cartridge type; this is to achieve a more compact configuration of the portable PEMFC system 100.

[0026] In another embodiment, the mounting plate 106 can be configured as a coupling plate l06a, so as to do away with the above external quick-disconnect couplings 11, 13. The coupling plate l06a has through passages for the water supply port and hydrogen gas port, and seals (such as O-rings) provide fluid sealing at the interfaces with the cartridge cap 103 and with the manifold 109. A separate electric connector l70a (not shown in the figures) is provided on the coupling plate l06a for connections to the heater 36 and thermocouple 37. Preferably, the coupling plate l06a is removeably connected onto the cartridge cap 103; in the field, to replace a cartridge 105, the coupling plate l06a is preferably disconnected from the manifold 109 and a new cartridge with an associated coupling plate l06a is reconnected onto the manifold 109 for quick replacement.

[0027] Again referring to FIG. 1A, water is stored in the water storage vessel 16. Water is supplied into the reaction chamber 10 via a water outlet port 14 located on the water storage vessel 16, a pump 15, a tubing 144 connecting a discharge port from the pump 15 to a check valve 146 and another tubing joined to the coupling 11 before terminating inside the reaction chamber 10. In one embodiment, the tubing 144 is selected to provide a predetermined rupture pressure range, so that during an emergency state of operation, for eg. inside the reaction chamber 10 or caused by an exterior environment outside the PEMFC 100, the tubing 144 is operable to rupture and stop the supply of water into the reaction chamber 10; when this happens, the check valve 146 ensures that the reaction chamber 10 remains closed. The tubing 144 and the check valve 146 provide a non- recoverable fail-safe mechanism for this portable PEMFC system 100.

[0028] Hydrogen produced in the reaction chamber 10 is supplied through a hydrogen outlet port or coupling 13 located on the mounting plate 106 and flows into a hydrogen line 20; preferably, the hydrogen line 20 is located substantially inside the manifold 109; inside the manifold 109, the hydrogen line 20 is tapped off to a pressure sensor 21 and a pressure relief valve 22. The hydrogen line 20 then goes into a cooling coil 120, which is disposed inside the water storage vessel 16, with an outlet of the cooling coil leading to a buffer tank 122. The hydrogen gas passes through the cooling coil 120 and is being cooled from a high temperature of about 300 degC (in the reaction chamber 10) to about 60-80 degC; any water that condenses out from the hydrogen gas is collected inside the buffer tank 122; the condensed water is recycled into the water storage vessel 16 via a recollection valve 126, which is operable by a signal from the controller 110 to a solenoid Sl . Hydrogen flowing through an outlet 124 at the buffer tank 122 is connected to a purifying filter or IEF 130 before the pressure is controlled by the pressure regulator 4. The hydrogen supply upstream of the purifying filter, IEF 130 is controlled by a supply valve 128 and an accompanying solenoid S2. The supply valve 128 may be used to stop the hydrogen gas supply when the fuel cell 2 is being purged, for eg. at an end of a power generation cycle or at an end of a start-stop cycle, as determined by the controller 110 and/or user. The controller 110 is electrically connected to the fuel cell 2 by a cable 6.

[0029] The water storage vessel 16 is spill-proof. As seen from FIG. 1A, the water storage vessel 16 is a fully enclosed vessel of about l50cc capacity but has a removeable membrane 140 made from a porous PTFE; the porous membrane 140 allows gas to pass through but is impermeable to water; any hydrogen gas that is recycled back through the water recollection line, ie. via port 123, may escape through the porous membrane 140; in this manner, pressure in the water storage vessel 16 is maintained at atmospheric pressure. The water storage vessel 16 being spill-proof and maintained at atmospheric pressure is a second safety feature built into the PEMFC system 100. In addition, a weighted clunk 142 is disposed at a free end of a water intake tube that leads to a suction port of the pump 15. The weighted clunk 142 ensures that the free end of the water intake tube is always submerged under water irrespective of orientation of the entire PEMFC housing 101.

[0030] In one embodiment, the hydride powder is a magnesium hydride (MgH 2 ). To hydrolyse MgH 2 , the reaction chamber 10 is preferably heated to about 80-100 degC; initial heating of the reaction chamber 10 is carried out by the controller 110 providing a signal to close a switch 162 connected to a heater port 163, which is electrically connected to the heater 36. Initial power for the heater 36 is obtained from a battery 25; once sufficient hydrogen is generated from the reaction chamber 10 and operation of the PEMFC system 100 is sustainable, electric power generated from the PEMFC is fed through the cable 6 to the controller 110. Hydrolysis of the MgH 2 is controlled by controlling the amount of water fed through the pump 15 according to a demand of an electric load 26 connected to an output port 165; in one embodiment, when the voltage V in the cable 6 exceeds that of the battery 25, electric power from the PEMFC charges up the battery 25. Hydrolysis of MgH 2 is exothermic and a temperature sensor 37, such as a thermocouple, monitors the temperature inside the reaction chamber 10. Signal from the temperature sensor 37 is fed to the controller 110, together with signals from the hydrogen pressure sensors 21, 132. As seen from FIG. 1A, the pressure sensor 21 is located near the reaction chamber 10 while the pressure sensor 132 is located at the PEMFC supply side (ie. near the fuel cell 2). Also seen from FIG. 1 A, a user may provide a start-stop signal to the controller 110. It is possible that the cable 6 includes one or more signals from the controller 110 to control operation of the fuel cell 2; for eg, a signal to the fuel cell 2 may control a ventilation fan 180 disposed in the fuel cell 2 to ensure a constant supply of 0 2 /air and to dissipate excess H 2 within the fuel cell 2.

[0031] FIG. 1B shows a portable hydrogen proton exchange membrane fuel cell (PEMFC) apparatus 200 incorporating the above PEMFC system 100. The PEMFC apparatus 200 is thus high-energy dense, portable and lightweight; it is used to extend mission endurance for users, such as soldiers, to increase mileage and/or to increase payload capacity for a manned system or unmanned system deployed in a field. The PEMFC apparatus 200 uses dry hydride powder 30 disposed in the reactor vessel 102 (which constitutes a replaceable hydride cartridge 105) to generate hydrogen on demand, and the controller 110 controls the electric output port 165 (via a signal 164) for powering up and/or charging an external load 26, such as a portable device, carried by the user. In addition, the controller 110 controls the electric supply power from the battery 25 to the heater 36.

[0032] The dry hydride cartridge 105 is rated at substantially 300Wh, and the battery 25 is selected for a power capacity to allow the hydride cartridge 105 to be hot-swapped to facilitate easy replacement of the hydride cartridge 105 without power interruption at the load 26 which is connected to the output port 165. As compared to batteries, carrying more hydride cartridges 105 would drastically improve and increase the energy-to-weight ratio due to its higher energy density, and consequently to extend mission endurance for soldiers. The above PEMFC system 100 includes 3 modules: (1) a fuel cell 2; (2) a water storage vessel 16; and (3) a reactor vessel 102. The respective modules are integrated and assembled inside a polymeric housing 101 which provides a physical case and protection for the various components to allow the PEMFC to function as a portable power generation system.

[0033] As seen from FIG. 2, the PEMFC 100 apparatus 200 includes the following:

i. the fuel cell stack 2; is the primary power source for the PEMFC system 100 that produces electric energy through the recombination reaction between oxygen ions and hydrogen ions across a proton exchange membrane;

ii. the battery 25; serves as a secondary power source for the PEMFC system 100 to supplement power during the start-up process before the fuel cell 2 supplies electric power, and during operation to allow hot-swapping of the hydride cartridge 105; the battery 25 is also used for heating up the reaction chamber 10 to initiate chemical reaction in the reactor vessel 102;

iii. the electric output port 165; this allows recharging of any portable battery cells and/or powering of portable electric apparatus carried by the user;

iv. the manifold 109; is to provide flow pathway before hydrogen gas enters the fuel cell 2.

The manifold 109 includes at least:

a. three miniature solenoid valves 126, 128, 136;

b. the hydrogen purifying filter (ion exchange filter or IEF) 130; the hydrogen purifying filter maintains purity of the hydrogen content; and

c. two pressure sensors 21, 132; v. the pressure regulator 4;

vi. the controller 110; and

vii. a USB port 170 for debugging and maintenance (including electronic data extraction).

An LCD display 172 is connected through a serial port (not shown in the figures) at the controller 110 to indicate to the user the amount of energy capacity left in the PEMFC system 100.

[0034] FIGs. 3 A and 3B show the water storage vessel 16. In FIGs. 3 A and 3B, the water storage vessel 16 is integrated in a housing lOla, which constitutes a sub-unit of the apparatus housing 101. The water storage vessel 16 includes the following components: i. the water storage vessel 16; it has a capacity of about 150 cc and contains some water to hydrolyse the hydride powder 30 to produce H 2 gas on demand;

ii. the cooling coil 120; serves to cool H 2 gas with the aid of water contained in the water storage vessel 16; temperature of the hydrogen gas is cooled from substantially 300 degC (in the reaction chamber 10) to a substantial range of 60 to 80 degC before hydrogen gas enters the fuel cell 2. Hydrogen gas above 80 degC would reduce the operation efficiency of the PEMFC system 100 and also shorten working lifespan of the proton exchange membrane; at the same time, water vapour in the hydrogen gas is removed by condensation in the buffer tank 122;

iii. the water pump 15; to supply controlled amounts of water to the reaction chamber 10 to allow hydrolysis of the hydride powder 30 to produce H 2 gas on-demand;

iv. the buffer tank 122; condenses and separates water vapor entrained in the hydrogen gas during hydrolysis of the hydride powder 30;

v. the recollection valve 126; recollects water from the buffer tank 122 and recycles water to the water storage vessel 16; and

vi. the weighted clunk 142; allows entry of water from the water storage vessel 16 to the water pump 15 irrespective of orientations of the water storage vessel 16 by making use of gravity force.

[0035] FIG. 4A shows the reactor vessel 102 according to one embodiment. The reactor vessel 102 contains the dry hydride powder 30 disposed inside the vacuum reactor vessel 102 that offers excellent heat insulation. This allows the contents in the reactor vessel 102 to retain their heat for an extended period of time, while an exterior of the reactor vessel remains cool and safe to touch. The reaction between water and magnesium hydride produces hydrogen gas, which is then supplied to the fuel cell 2 to generate useful (electric) energy to the user. The reactor vessel 102 contains of the following sub-components:

i. the heater 36; initially powered by the battery 25 to supply sufficient heat to initiate hydrolysis of the hydride powder 30;

ii. the water delivery tube; delivers controlled amounts of water from the water storage vessel 16 through the water pump 15 to the hydride powder 30;

iii. the H 2 gas outlet port; H 2 gas produced during hydrolysis of the hydride powder 30 is directed out of the reaction chamber 10 to the fuel cell 2; and

iv. the thermocouple 37; to monitor the reaction temperature within the reaction chamber 10.

[0036] FIG. 4B shows a hydrogen cartridge 105 a according to another mounting configuration. As shown in FIG. 4B, the hydrogen cartridge l05a is removeable connected to a base plate of the PEMFC apparatus 200 via a manifold mounting l06b. Similar to the above coupling plate l06a mounting configuration, the water inlet port and the hydrogen gas outlet port are configured on the manifold mounting l06b, while a separate electrical connector l07b provides connections to the heater 36 and thermocouple 37. In one embodiment, the hydrogen cartridge 105 is connected to the base plate of the PEMFC apparatus via a twistlock mechanism for quick disconnection or replacement; in another configuration, the hydrogen cartridge 105 is connected to the base plate via a plug-and- catch mechanism for quick disconnection or replacement.

[0037] Now, operation of the hydrogen generation system (HGS) is described: ETpon switching on, water from the water storage vessel 16 is supplied in controlled amounts into the hydride cartridge 105 through the water pump 15. The heater 36 is powered up by the battery 25 to heat up the reaction chamber 10 to initiate and to promote the reaction between the hydride powder 30 and water to produce H 2 gas. When the reaction becomes optimized or stabilised, the exothermic nature of the hydrolysis reaction allows for self- sustainment of reaction and no longer requires the aid of the heater 36. The H 2 produced during the reaction is cooled along the way to substantially 60-80 degC as hydrogen flows through the manifold 109 and cooling coil 120 towards the fuel cell 2. At the fuel cell, H ions and O ions undergo recombination and, as a result, produce electric power, which is channelled to the load 26 (such as charging of an external battery or electric device), for eg., carried by the user.

[0038] During substantially the first 10 minutes of operation, the energy output from the PEMFC system 100 is predominantly contributed by the battery 25 while chemical reaction builds up within the reaction chamber 10. When significant amount of H 2 (flow) is generated from the reaction to produce electric energy, operation of the fuel cell 2 takes over supply from the battery 25 to become the source of electric power as seen at the electric output port 165. The battery 25 together with any rechargeable battery connected to the output port 165 would in-turn be recharged by the electric energy produced at the fuel cell 2.

[0039] The controller 110 includes an algorithm that responds adaptively to the hydrogen utilization level remaining in the hydride cartridge 105. For eg., if the hydride cartridge 105 is about half utilized, there is likelihood of water being present in the reaction chamber 10; in this case, more heat is required and the controller 110 algorithm responds adaptively to extend the heater heating duration before more water is supplied into the reaction chamber 10.

[0040] FIGs. 5A-5E show a pouch 300 for carrying the above PEMFC apparatus 200. As shown in FIGs. 5A-5B, the pouch 300 is suitable to be carried on a back of the user or soldier, with a cover 302 for closing a top of the pouch 300. On an outside surface of the pouch 300 is an air inlet vent 320 through which air and oxygen is supplied to the PEM stack 2. FIG. 5C shows a rear view of the pouch 300; FIG. 5C shows shoulder straps 304 for carrying by the user, and some velco strips 306 for attaching the pouch 300 onto a vest worn by the user; on the inner surface of the pouch (as seen in FIG. 5B when it is in use), there is an air exhaust vent 324 for venting air, unconsumed hydrogen and water vapour from the PEM stack 2, during power generation and/or purging; the air exhaust vent 324 is more clearly seen in FIG. 5C. FIG. 5D is an inside view of the pouch with the cover 302 being in an open position. As can be visualised in FIG. 5D, the inside of the pouch 300 is provided with some foam cushions 312 to protect the PEMFC apparatus 200 and EMI shield linings 314 to prevent radio interference. FIG. 5E shows more clearly the air intake vent 320. [0041] Yet in another embodiment, instead of using velco for attaching the pouch 300 onto the vest worn by the user, it is possible to use some webbings and buckles or buttons to provide such attachment. [0042] While specific embodiments have been described and illustrated, it is understood that many changes, modifications, variations and combinations thereof could be made to the present invention without departing from the scope of the present invention. For eg., the vessel cap 103 is removeable by turning a twist-lock that connects the vessel cap 103 to the reactor vessel 102.