1. Field of the Invention
The invention generally relates to a hydrogen generation device and a fuel cell having the hydrogen generation device, and more particularly, to a hydrogen generation device using a solid fuel and a fuel cell having the hydrogen generation device.
2. Description of Related Art
A fuel cell is an electricity generation apparatus that directly converts chemical energy into electrical energy. Compared to the conventional electricity generation techniques, a fuel cell offers lower pollution, lower noise, higher energy density, and higher energy conversion efficiency and therefore the fuel cell is a very promising clean energy source. Fuel cells may be applied to portable electronic products, home electricity generation systems, transportation vehicles, military equipments, the space industry, and small-scale electricity generation systems, etc.
Different fuel cells have different applications according to the operating principles and operating environments thereof. Proton exchange membrane fuel cells (PEMFCs) and direct methanol fuel cells (DMFC cells) are mostly applied to portable power sources. Both PEMFC and DMFC are low temperature fuel cells using a proton exchange membrane for conducting protons. According to the operating principle of such a fuel cell, oxidation of hydrogen is carried out in the anode catalyst layer to produce hydrogen ions H+and electrons e−(the operating principle of PEMFC), or water oxidation of methanol is carried out in the anode catalyst layer to produce hydrogen ions H+, carbon dioxide (CO2), and electrons e−(the operating principle of DMFC), wherein the hydrogen ions H+are conducted by the proton exchange membrane to the cathode, while the electrons e−are first transmitted by an external circuit to the load before they are conducted to the cathode. Herein a redox reaction between the oxygen supplied to the cathode and the hydrogen ions H+and electrons e−is carried out in the cathode catalyst layer and water is produced. The hydrogen supplied to the anode may be obtained through a solid NaBH4 hydrogen storage technique, wherein water is added into solid NaBH4, and the two react with each other to produce hydrogen.
If a large amount of water is directly reacted with solid NaBH4, the reaction will be too energetic to generate hydrogen stably. Thus, additional valves have to be disposed in the system for controlling the release of hydrogen, and this will increase the complexity, structural strength, and cost of the system. In addition, a filling (for example, silicon) may be added into the solid NaBH4 to slow down the reaction. However, this will reduce the weight percent of hydrogen generated in the reaction.
Accordingly, the invention is directed to a hydrogen generation device, wherein a solid fuel slowly reacts with water to release hydrogen stably.
The invention is directed to a fuel cell, wherein a solid fuel in a hydrogen generation device of the fuel cell slowly reacts with water to release hydrogen stably.
Additional aspects and advantages of the invention may be further understood from the description that follows.
According to an embodiment of the invention, a hydrogen generation device adapted to a fuel cell is provided. The hydrogen generation device includes a containing tank and a buffer layer. The buffer layer is disposed in the containing tank and divides the containing tank into a first containing space and a second containing space. The first containing space is capable of containing a liquid reactant. The second containing space is capable of containing a first solid fuel. The liquid reactant is capable of entering the second containing space through the buffer layer and reacts with the first solid fuel to generate hydrogen.
According to an embodiment of the invention, a fuel cell including a hydrogen generation device, a fuel cell stack, and a guiding structure is provided. The hydrogen generation device includes a containing tank and a buffer layer. The buffer layer is disposed in the containing tank and divides the containing tank into a first containing space and a second containing space. The first containing space is capable of containing a liquid reactant. The second containing space is capable of containing a first solid fuel. The liquid reactant is capable of entering the second containing space through the buffer layer and reacting with the first solid fuel to generate hydrogen. The guiding structure is connected between the hydrogen generation device and the fuel cell stack and is capable of guiding the hydrogen generated in the reaction between the first solid fuel and the liquid reactant to the fuel cell stack.
As described above, in an embodiment of the invention, a buffer layer is disposed in a containing tank and is located between a liquid reactant and a solid fuel. Thus, the liquid reactant may be continuously conducted to the solid fuel through the buffer layer, so that the solid fuel and the liquid reactant may slowly react with each other to release hydrogen stably. Thereby, the weight percent of the hydrogen generated in the reaction is increased, and both the volume and the cost of the entire system are reduced.
Other objectives, features and advantages of the invention will be further understood from the further technological features disclosed by the embodiments of the invention wherein there are shown and described preferred embodiments of this invention, simply by way of illustration of modes best suited to carry out the invention.
The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.
In the following detailed description of the preferred embodiments, reference is made to the accompanying drawings which form a part hereof, and in which are shown by way of illustration specific embodiments in which the invention may be practiced. In this regard, directional terminology, such as “top,” “bottom,” “front,” “back,” etc., is used with reference to the orientation of the Figure(s) being described. The components of the invention may be positioned in a number of different orientations. As such, the directional terminology is used for purposes of illustration and is in no way limiting. On the other hand, the drawings are only schematic and the sizes of components may be exaggerated for clarity. It is to be understood that other embodiments may be utilized and structural changes may be made without departing from the scope of the invention. Also, it is to be understood that the phraseology and terminology used herein are for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Unless limited otherwise, the terms “connected,” “coupled,” and “mounted” and variations thereof herein are used broadly and encompass direct and indirect connections, couplings, and mountings. Similarly, the terms “facing,” “faces” and variations thereof herein are used broadly and encompass direct and indirect facing, and “adjacent to” and variations thereof herein are used broadly and encompass directly and indirectly “adjacent to”. Therefore, the description of “A” component facing “B” component herein may contain the situations that “A” component directly faces “B” component or one or more additional components are between “A” component and “B” component. Also, the description of “A” component “adjacent to” “B” component herein may contain the situations that “A” component is directly “adjacent to” “B” component or one or more additional components are between “A” component and “B” component. Accordingly, the drawings and descriptions will be regarded as illustrative in nature and not as restrictive.
The first containing space 110a is capable of containing a liquid reactant 50. The second containing space 110b is capable of containing a solid fuel 60. In the embodiment, the buffer layer 120 includes a filling material 122 and a solid fuel 124, wherein the filling material 122 and the solid fuel 124 may respectively be silicon and NaBH4 powder. The liquid reactant 50 in the first containing space 110a reacts with the solid fuel 124 to generate hydrogen, such that the buffer layer 120 is turned into a porous structure layer 120′, as shown in
In the embodiment, the liquid reactant 50 and the solid fuel 60 (124) may respectively be liquid water and NaBH4 powder. However, the invention is not limited thereto, and the liquid reactant 50 and the solid fuel 60 (124) may also be other substances capable of generating hydrogen. Besides, catalysts may also be added to the solid fuel 60 (124) to accelerate the reaction between the liquid reactant 50 and the solid fuel 60 (124).
The entire structure after the reaction is illustrated in
NaBO2•4H2O.
In the embodiment, the containing tank 110 has an opening 112 connected with the second containing space 110b, and the hydrogen generation device 100 further includes a liquid impermeable and gas permeable membrane 130 covering the opening 112. Thus, the hydrogen generated in the reaction between the solid fuel 60 and the liquid reactant 50 may be exhausted from the containing tank 110 through the liquid impermeable and gas permeable membrane 130, and the water solution 70 generated in the reaction between the solid fuel 60 and the liquid reactant 50 is blocked by the liquid impermeable and gas permeable membrane 130 and will not leak out. Besides, the hydrogen generation device 100 may further include a water absorbing structure 140 disposed in the first containing space 110a. The water absorbing structure 140 absorbs the liquid reactant 50 to form water-based adhesive for securing the liquid reactant 50 in the first containing space 110a. However, the invention is not limited thereto, and in other embodiments, the water absorbing structure 140 may be omitted and the liquid reactant 50 may be directly contained in the first containing space 110a.
The liquid permeable and gas impermeable membrane 320 in the embodiment may be a proton exchange membrane. To be specific, the liquid permeable and gas impermeable membrane 320 may be a polystyrene sulfonic acid (PSSA) membrane, a perfluorosulfonic acid membrane, a tetrafluoroethylene (TFE) porous membrane, a TFE porous and perfluorosulfonic acid composite membrane, a non-fluorinated proton exchange membrane, a polyethersulfone, or a partially-fluorinated proton exchange membrane. Besides, the liquid permeable and gas impermeable membrane 320 may also be made of poly(ether-ether-ketone) (PEEK), polyimide, or polyamide-imide (PAI).
Through the disposition described above, the liquid reactant 50 moves towards the buffer layer 720 and the second containing space 710b through the opening 792 and reacts with the solid fuel 60 to generate hydrogen. As shown in
The hydrogen generation devices described in foregoing embodiments may be applied to a fuel cell for supplying hydrogen required by the anode reaction of the fuel cell, which will be described below by taking the hydrogen generation device 100 illustrated in
In summary, in an embodiment of the invention, a buffer layer is disposed in a containing tank and is located between a liquid reactant and a solid fuel. The liquid reactant is constantly conducted to the solid fuel through the buffer layer so that the solid fuel slowly reacts with the liquid reactant and accordingly releases hydrogen stably. Since no filling material is added to the solid fuel, the weight percent of hydrogen generated in the reaction is increased, and both the volume and cost of the entire structure are reduced. Moreover, microporous layers may be stacked on the buffer layer to further slow down the reaction between the liquid reactant and the solid fuel. Furthermore, the pressure in the first containing space for containing the liquid reactant may be increased by disposing a piston or triggering a reaction in the first containing space, so that the liquid reactant is pressed downwards and reacts with the solid fuel in the second containing space to generate hydrogen.
The foregoing description of the preferred embodiments of the invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form or to exemplary embodiments disclosed. Accordingly, the foregoing description should be regarded as illustrative rather than restrictive. Obviously, many modifications and variations will be apparent to practitioners skilled in this art. The embodiments are chosen and described in order to best explain the principles of the invention and its best mode practical application, thereby to enable persons skilled in the art to understand the invention for various embodiments and with various modifications as are suited to the particular use or implementation contemplated. It is intended that the scope of the invention be defined by the claims appended hereto and their equivalents in which all terms are meant in their broadest reasonable sense unless otherwise indicated. Therefore, the term “the invention”, “the present invention” or the like does not necessarily limit the claim scope to a specific embodiment, and the reference to particularly preferred exemplary embodiments of the invention does not imply a limitation on the invention, and no such limitation is to be inferred. The invention is limited only by the spirit and scope of the appended claims. The abstract of the disclosure is provided to comply with the rules requiring an abstract, which will allow a searcher to quickly ascertain the subject matter of the technical disclosure of any patent issued from this disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. Any advantages and benefits described may not apply to all embodiments of the invention. It should be appreciated that variations may be made in the embodiments described by persons skilled in the art without departing from the scope of the invention as defined by the following claims. Moreover, no element and component in the present disclosure is intended to be dedicated to the public regardless of whether the element or component is explicitly recited in the following claims.
Number | Date | Country | Kind |
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201010130007.7 | Mar 2010 | CN | national |
This application claims the priority benefit of China application serial no. 201010130007.7, filed on Mar. 5, 2010. The entirety of the above-mentioned patent application is hereby incorporated by reference herein and made a part of this specification.