JP2008034133A - Fuel storage gel for fuel cell; fuel storage/extraction kit for fuel cell using it; fuel storage/extraction system for fuel cell; fuel storage method for fuel cell; fuel extraction method for fuel cell; fuel cartridge for fuel cell; and fuel cell and portable device using them - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel storage gel for a fuel cell enhanced in versatility by expanding the range for selecting material usable for gelatinization; and to provide a fuel storage gel for a fuel cell capable of balancing high fuel storage power with high fuel extraction efficiency, excelling in handleability and safety, and capable of enhancing fuel extraction yield, and of preventing mixture of a side product and impurities into a re-liquefied fuel as needed. <P>SOLUTION: This fuel storage gel is used for including, swelling and gelatinizing a fuel gelatinization resin formed of a cationic polymer electrolyte, and a methanol fuel. The fuel storage gel for a fuel cell can release the methanol fuel in a gelatinized substance by generating reliquefying ions by addition of a reliquefying ion generation agent to make the reliquefying ions coexist with the polymer electrolyte to form salts of both of them, and contracting the fuel gelatinization resin. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

The present invention relates to a fuel cell fuel storage gel, a fuel cell fuel storage and extraction kit using the same, a fuel cell fuel storage and extraction system, a fuel cell fuel storage method, a fuel cell fuel extraction method, and a fuel cell fuel The present invention relates to cartridges, and fuel cells and portable devices using them.
More specifically, fuel cell fuel storage gel with excellent safety and improved handling, fuel cell fuel storage and extraction kit using the same, fuel cell fuel storage and extraction system, fuel cell fuel storage method, and fuel cell The present invention relates to a fuel removal method, a fuel cartridge for a fuel cell, a fuel cell using the same, and a portable device.

  A fuel cell enables power generation by directly taking out electrical energy using an electrochemical reaction of fuel. There are advantages such as high power generation efficiency, extremely low emission of harmful substances, and easy weight reduction and miniaturization.

  Among these, methanol, which is safe with respect to a fuel cell using hydrogen as a fuel and excellent in handleability, is suitable as a fuel for fuel cells of portable electronic devices and the like, and its improved development and spread are expected. However, methanol is also a volatile flammable substance and may have an effect when inhaled by the human body. Furthermore, methanol is known to produce formic acid and formaldehyde as an oxidation reaction intermediate, which may also affect the human body. Even when methanol is used as a fuel, development of a fuel cell system provided with a fail-safe mechanism is also required.

  In response to this demand, a method of solidifying and storing fuel has been recently proposed (see, for example, Patent Documents 1 to 4 and Non-Patent Document 1). However, these disclosed ones use solidified fuel, but do not pay attention to efficiently removing the fuel, and there is a fuel that cannot be removed from the solidified material during power generation or the fuel is eluted. For this reason, a large amount of eluent (for example, water) is required, and it is difficult to separate the fuel and the adsorbent.

Japanese Examined Patent Publication No. 4-13828 JP 2001-093558 A JP 2004006335 A JP 2005-203335 A Satoshi Yagi, Shigeaki Sato, “Development of“ solid methanol ”fuel for direct methanol fuel cell”, Fuel Cell, Vol. 5, no. 4, 2006, pp. 72-75

In order to solve the above-mentioned conventional problems, the inventors of the present invention provide a gelled product comprising at least a fuel and a gelling agent, and the gelled product causes re-liquefaction of the fuel by the action of the reliquefaction agent. A fuel mixture for a battery has been devised (see Japanese Patent Application Nos. 2005-018092 and 2005-236990, and International Patent Application No. PCT / JP2006 / 301256).
Here, if a macromolecule such as a polymer absorbent is used to increase the holding power using methanol as a fuel, the polymer absorbent does not swell sufficiently, or even if it swells, the penetration rate of the reliquefaction agent Is too slow.

  Accordingly, an object of the present invention is to provide a fuel storage gel for a fuel cell with a wider range of materials that can be used for gelation and improved versatility. In addition, it achieves both high fuel storage capacity and high fuel extraction efficiency (reliquefaction rate), and is excellent in handling and safety. Also, fuel extraction yield (the amount of fuel extracted by reliquefaction relative to the amount of stored fuel) It is an object of the present invention to provide a fuel storage gel for a fuel cell that can increase by-product ratio) and can suppress mixing of by-products and impurities into the reliquefied fuel as necessary. Furthermore, a fuel cell fuel storage and extraction kit using the fuel cell fuel storage gel, a fuel cell fuel storage and extraction system, a fuel cell fuel storage method, a fuel cell fuel extraction method, and a fuel cell fuel cartridge, An object of the present invention is to provide a fuel cell and a portable device using the same.

Said subject is achieved by the following means.
(1) A fuel storage gel containing a fuel gelation resin comprising a cationic polymer electrolyte and a methanol fuel to be swollen and gelled, wherein a reliquefied ion generator is added to generate reliquefied ions, A fuel storage gel for a fuel cell, wherein reliquefied ions and the polymer electrolyte are allowed to coexist to form a salt of both, and the fuel gelled resin is contracted to release methanol fuel in the gelled product.
(2) The fuel storage gel for a fuel cell according to (1), wherein a reliquefied ion generating resin is added to the fuel storage gel as a reliquefied ion generating agent to generate reliquefied ions in the gelled product.
(3) The fuel storage gel for a fuel cell according to (1) or (2), wherein the reliquefied ions are ammonium ions.
(4) The fuel for a fuel cell according to any one of (1) to (3), wherein the reliquefied ions are cations generated in the gelled product by adding a reliquefied ion generating resin to the gelled product. Storage gel.
(5) The fuel storage gel for a fuel cell according to any one of (2) to (4), wherein the reliquefied ion generating resin is a salt of reliquefied ions.
(6) An aqueous solution, a methanol solution, or an aqueous methanol solution containing reliquefied ions in a liquid using a reliquefied ion generating resin is added to the gelled product to generate reliquefied ions in the gelled product ( The fuel storage gel for fuel cells according to any one of 1) to (5).
(7) Any one of (1) to (6), wherein the reliquefaction ion generator is made of at least one resin selected from the group consisting of a strong acid cation exchange resin, a weak acid cation exchange resin, and a chelate resin. The fuel storage gel for a fuel cell according to Item.
(8) The reliquefied ion generator is a gel-like resin and comprises at least one resin selected from the group consisting of a strong acid cation exchange resin, a weak acid cation exchange resin, and a chelate resin. The fuel storage gel for a fuel cell according to any one of 6).
(9) The fuel cell according to any one of (1) to (8), wherein the cationic polymer electrolyte is at least one selected from the group consisting of polyacrylic acid and a cross-linked polyacrylic acid. Fuel storage gel.
(10) The fuel storage gel for a fuel cell according to any one of (1) to (9), wherein the gelled product is a ring gel or a double network gel.
(11) A gelled fuel (a) that contains a fuel gelled resin composed of a cationic polymer electrolyte and methanol fuel and stores the fuel by gelling, and a reliquefied ion generating resin (b)
A fuel storage and retrieval kit combining at least
A reliquefied ion generating resin (b) is added to the gelled fuel (a) to generate reliquefied ions in the gelled product, and the reliquefied ions coexist with the polymer electrolyte to form a salt of both. A fuel storage and removal kit for a fuel cell, wherein the fuel gelled resin is shrunk to release methanol fuel.
(12) A fuel storage and extraction system for storing fuel by gelling a fuel gelled resin comprising a cationic polymer electrolyte and methanol fuel,
A reliquefied ion generator is added to the gelled product to generate reliquefied ions, the reliquefied ions and the polymer electrolyte coexist to form a salt of both, and the fuel gelled resin is shrunk to methanol A fuel storage and retrieval system for a fuel cell capable of releasing fuel.
(13) (A) A fuel gelled resin comprising a cationic polymer electrolyte and methanol fuel are contained to swell and gelate, and the fuel is stored.
(B) A reliquefied ion generating resin is added to the gelled product to generate reliquefied ions in the gelled product, and the reliquefied ions and the polymer electrolyte coexist to form both salts, A fuel storage and retrieval system for a fuel cell in which the fuel gelled resin is shrunk to release methanol fuel.
(14) The fuel storage / extraction system for a fuel cell according to (12) or (13), wherein the concentration of reliquefied ions contained in the released fuel is reduced by a filter.
(15) The fuel storage / extraction system for a fuel cell according to (14), wherein the filter is a filter including an ion exchange resin.
(16) When storing a fuel gelled resin composed of a cationic polymer electrolyte and methanol fuel to swell the gel and store the fuel, a reliquefied ion generator is added to the gelled product to generate reliquefied ions. A fuel storage method for a fuel cell, wherein the polymer electrolyte and reliquefied ions are allowed to coexist to form a salt of the both, and the fuel gelation resin is shrunk to release the fuel by gelling and storing the methanol fuel .
(17) (A) A gelled product containing a fuel gelled resin composed of a cationic polymer electrolyte and methanol fuel to swell and store the fuel,
(B) A reliquefied ion generating resin is added to the gelled product to generate reliquefied ions, the reliquefied ions and the polymer electrolyte coexist to form a salt of both, and the fuel gelled resin is A fuel take-out method for a fuel cell that is contracted to release and take out fuel.
(18) A low-concentration methanol aqueous solution containing the re-liquefied ion generating resin is added to the gelled product, the methanol whose concentration is gradually increased is released, and the methanol concentration is controlled and taken out and supplied to the fuel cell (17 ) The fuel take-out method for a fuel cell described in
(19) A fuel cartridge for a fuel cell, comprising at least the fuel storage gel for a fuel cell according to any one of (1) to (10) and an ion removal filter.
(20) A fuel cartridge for a fuel cell, wherein the fuel cartridge for a fuel cell according to (19) and a reliquefied ion generating resin are combined at least in a kit.
(21) A fuel cell comprising at least the fuel cartridge for a fuel cell according to (19) or (20).
(22) A portable device comprising the fuel cell according to (21).

The fuel storage gel for fuel cells of the present invention broadens the range of materials that can be used for gelation, increases versatility, and achieves both high fuel retention and high reliquefaction efficiency, and solid impurities after reliquefaction Separation from methanol fuel is easy and excellent in handling and safety. Moreover, a high fuel extraction yield can be realized, and contamination of impurities and by-products into the reliquefied fuel can be suppressed as necessary.
Furthermore, according to the fuel cell fuel storage and extraction kit, fuel cell fuel storage and extraction system, fuel cell fuel storage method and fuel cell fuel extraction method using the fuel cell fuel storage gel of the present invention, The fuel can be removed safely and quickly when necessary, and efficient power generation suitable for various portable devices can be performed.

The present invention is described in detail below.
In the fuel cell fuel storage gel of the present invention, methanol is used as the fuel. The methanol fuel to be stored may be used alone or in combination with other compounds, methanol aqueous solution, methanol mixture containing gel ions described later, and methanol mixture combined with gel ion generation resin A liquid or the like can be used. Moreover, you may contain other alcohol compounds, an additive, etc. suitably.

The fuel storage gel for a fuel cell of the present invention is a fuel storage gel that contains a fuel gelled resin composed of a cationic polymer electrolyte and a methanol fuel to swell and gel (in the present invention, the gel is a swellable gel). This includes not only the solidified product that has been completed but also those that are in the process of swelling.) This fuel gelling resin may be gelled by the action of gelling ions described later, may be a chemical gel, or may be a physical gel exhibiting thixotropic properties. In addition, even if the gelled resin alone or together with methanol fuel constitutes a network structure by cross-linking, hydrogen bonding, molecular entanglement, etc., and the gel structure is formed with the fuel incorporated therein Good.
Furthermore, uniform organic-inorganic hybrid gels (see, for example, Emiko Oda, Naofumi Nagata, Akinori Toyoda, Hidemitsu Furukawa, Proceedings of the Society of Polymer Science, 53 (2), 3263 (2004)), the mesh behaves like a pulley. Ring gels (see, for example, Y. Okumura, K. Ito, Adv. Mater., 13, 485 (2001)) or multiple gel constructs to form nested structures or double networks when gelled. A gelled resin may be used, and a gelled product having a ring gel structure or a double network gel structure is particularly preferable. Nested structure or double network structure refers to an entangled structure of a plurality of types of gels, for example, a tightly cross-linked rigid strong electrolyte gel (1st network) and a loosely cross-linked bendable neutrality. The gel (2nd network) is entangled, and Hidemitsu Furukawa “Gel Complex Structure—Nonuniformity and Mechanical Properties of the Network” Polymer, Vol. 54, 458-461 pages, July 2005, etc. can also be used preferably. Other thickeners and polymer absorbents described later can also be used.

  The fuel gelled resin used in the fuel storage gel for fuel cells of the present invention comprises a cationic polymer electrolyte, and may be a crosslinked polymer electrolyte or a non-crosslinked polymer electrolyte.

  Examples of the non-crosslinked polymer electrolyte include polymer compounds having an acidic polar group, polyacrylic acid or a derivative thereof is preferable, and polyacrylic acid is more preferable.

  Examples of the crosslinked polymer electrolyte include those obtained by crosslinking the above-mentioned non-crosslinked polymer gelling agent and derivatives thereof (crosslinked polyacrylic acid and derivatives thereof). Reticulated product, reticulated product by self-crosslinking, reticulated product by light / radiation irradiation, insolubilized cross-linked product by copolymerization of hydrophobic monomer, insolubilized cross-linked product by introduction of crystalline polymer block, cross-linked product by polyvalent metal cation, hydrogen bonding For example, a cross-linked product by introduction of secondary bonds and the like. In the case of a cross-linked polymer electrolyte, the absorption power (affinity with osmotic pressure, osmotic pressure, etc.) that attempts to take the fuel into the gel by adjusting the cross-linking density, and the power to stop the absorption (mesh) The amount of absorption may be controlled by balancing the elastic force based on the structure).

  The molecular weight of the fuel gelled resin is not particularly limited, but is preferably a mass average molecular weight of 100,000 to 10,000,000, more preferably 1,000,000 or more. (In the present invention, molecular weight means mass average molecular weight unless otherwise specified). However, a fuel gelled resin having a higher molecular weight that has been crosslinked using a crosslinking agent or the like can also be used.

Here, the polarity of the cationic polymer electrolyte can be adjusted according to the type of functional group thereof. If the strength is explained together with the basic one in consideration of the resin described later, for example, it can be distinguished into strong polarity (strong acidity, strong basicity) and weak polarity (weak acidity, weak basicity). it can. In the present invention, for the acid-base strength, for example, a predetermined polymer electrolyte is put into a methanol aqueous solution having a predetermined concentration and the degree of ionization is measured, and the acid-base strength can be generally substituted. Specifically, it can be determined from the pH when 1 g of polymer electrolyte is added to 1 L (liter) of water. You may consider the exchange capacity of a polymer electrolyte, a solution composition, etc. as needed. In the present invention, unless otherwise specified, strong acidity is an acid strength generally corresponding to a resin having a —SO ³ group as a functional group (for example, strongly acidic ion exchange resin PK212 (trade name) manufactured by Mitsubishi Chemical Corporation). acid corresponding to roughly corresponding acid strength resin having a group (e.g., manufactured by Nippon Shokubai Co., Ltd. polymeric absorbent AQUALIC CA (trade name) ^- refers to acidic strength), the weakly acidic -COO as a functional group to Strength). On the other hand, strong basicity refers to a base strength substantially equivalent to a resin having a —NR ₃ ⁺ group (R is a methyl group or an ethyl group) (for example, a basic ion exchange resin PA308 (trade name) manufactured by Mitsubishi Chemical Corporation). refers to the corresponding basic strength), -NR ₂ group as a functional group is a weak base (R bases intensity corresponding approximately to a resin having a methyl group or an ethyl group) (for example, basic ion exchange Dow Chemical Basic strength corresponding to resin marathon WBA (trade name). In addition, the chelate type resin described later can be used as a resin having a weaker polarity than that of the above weak polarity.

The amount of the fuel gelled resin added is not particularly limited, but the viscosity of the fuel gelled product (in the present invention, unless otherwise specified, the viscosity represents the viscosity at room temperature (25 ° C.)) is 8 Pa · sec or more. It is preferable to adjust appropriately according to the kind of fuel gelled resin. For example, when polyacrylic acid or a cross-linked polyacrylic acid is used as a gelling agent, 0.1 to 100 parts per 100 parts by mass of methanol fuel. It is preferable that it is a mass part, and it is more preferable that it is 0.1-10 mass parts. At this time, it is preferable that the amount of the fuel gelled resin added is small so as to ensure the fuel content. If the viscosity of the gelled fuel is high, the scattering of the fluid can be reduced when the tank is broken or carried, so that safety can be ensured.

Further, among the materials obtained by crosslinking polyacrylic acid, a so-called polymer absorbent that becomes a huge bead-like molecule can be preferably used. The polymer absorbent is one of widely used materials used for diapers and the like, and is supplied stably and can be obtained at a relatively low cost. Examples of the polymer absorbent include those having a functional group such as a carboxyl group in the main chain. Cationic polymer absorbents are in the form of ammonium salt or sodium salt at the time of shipment and are inherently weakly acidic, but are often neutralized with sodium hydroxide or aqueous ammonia. At this time, when using the fuel storage gel for a fuel cell of the present invention, it is preferable to perform a pretreatment for removing ammonium ions and sodium ions bonded to the polymer absorbent. This process is similar to a process called ion-exchange resin conditioning. Since the polymer absorbent from which ions have been removed is swollen, it is preferably dried at room temperature.
The polymer absorbent is preferably a macromolecule having a high molecular weight, for example, a molecular weight of 100,000 to 10,000,000 is preferable, and a molecular weight of 1,000,000 or more is more preferable. By using such an absorbent having a high molecular weight, for example, a hard gelled fuel that does not sag even when the container is turned upside down can be obtained. If such a polymer absorbent is used, it will not gel when it is mixed with methanol fuel, and it may take too much time to gel, but in the fuel storage gel of the present invention, In some cases, gelation can be promoted by the action of gelling ions described below.

  In the fuel storage gel of the present invention, in order to promote the swelling gelation, it is preferable that gelled ions coexist in the composition containing the fuel gelled resin and the methanol fuel.

Gelling ions are ions that promote gelation by the fuel gelling resin. Here, since the amount of the salt composed of the gelled resin and the gelled ions in the methanol aqueous solution varies depending on the combination of the gelled resin and the gelled ions, the type and concentration of the gelled ions are It depends not only on the type of gelled resin but also on the concentration of the aqueous methanol solution used. In many cases, the polarity of the gelled ions is determined in relation to the polarity of the polymer electrolyte of the fuel gelled resin. In general, a polyelectrolyte is composed of a functional group bound to a main chain of a resin and a counter ion bonded to the functional group. Therefore, the gelled ion is an ion that promotes ionization between the functional group and the counter ion, and the ion having the same polarity as the functional group of the polymer electrolyte is used. Specifically, when a cationic polymer electrolyte (polyacrylic acid or the like) is used as the polymer electrolyte, the gelling ion becomes an anion because the functional group fixed to the main chain is a carboxyl group. More specifically, examples include an anion, an oxonium ion, a chloride ion, a sulfate ion, and a phosphate ion that separate a proton bonded to the carboxyl group from the carboxyl group. Of these, an oxonium ion is preferable.

The method for allowing gelling ions to coexist in the fuel composition is not particularly limited. For example, even when charged in methanol fuel, the fuel mixture is mixed with the gelling ion generator after mixing the methanol fuel and the fuel gelling resin. (In the present invention, “agent” is used to mean not only a single compound but also a composition and a resin). At this time, even if the gelling ions are directly supplied from the gelling ion generator and generated, the group of the gelling ion generator reacts with water (H ₂ O) or the like indirectly. The generated ion (for example, an oxonium ion generated by the NH ₂ group by extracting a proton from water to become an NH ₃ ⁺ group) may be used.

  Examples of the gelling ion generator include agents containing gelling ions (specifically, neutral salts, acidic salts, alkaline salts, polymer electrolyte resins, aqueous solutions thereof, and methanol solutions thereof). It is done. In particular, it is preferable to use an aqueous solution, a resin that generates gelling ions (hereinafter referred to as “gelling auxiliary resin”), or the like, and it is more preferable to use a gelling auxiliary resin. That is, for example, when a low molecular weight salt or electrolyzed water thereof is used as a gelling ion generator, counter ions are generated and diffused in the fuel composition together with the gelling ions. For example, when ammonium chloride is generated as gelling ions using ammonium chloride, chlorine ions are generated as counter ions. This counter ion is mixed in the methanol fuel when reliquefied, and its removal is difficult. Such counter ions (by-products) may deteriorate the durability of the fuel cell electrodes and the like when methanol fuel is taken out and used for power generation. Therefore, it is preferable to remove. On the other hand, if a gelling auxiliary resin is used as the gelling ion generator, the resin portion after the gelling ion release will not diffuse into the composition, and can be easily removed without mixing. Therefore, it is preferable.

  The swelling strength of the gelling auxiliary resin is not particularly limited, but is preferably lower than the swelling strength of the fuel gelling resin. In this way, even when the gelled resin swells, swelling of the gelling auxiliary resin is suppressed and kept in a certain shape, so that it can be easily separated from the fuel gelled product even when removed, for example. it can. In general, the swelling strength of the resin can be adjusted by the composition of the resin, and in particular by the type of functional group and the amount of crosslinking. That is, a desired resin can be obtained by reducing the swelling amount by changing the type of functional group of the gelling auxiliary resin or increasing the crosslinking amount. The swelling strength (absorption capacity) of the resin in the methanol aqueous solution in the present invention is a value measured by the tea bag method. Specifically, it is a value obtained by adding a predetermined resin and measuring the swelling strength with an aqueous methanol solution in which the amount of protons is adjusted. The larger the value, the easier the swelling.

  The molecular weight of the gelling ion generating resin is not particularly limited, but is preferably a mass average molecular weight of 100,000 to 10,000,000, more preferably 1,000,000 or more. A crosslinked resin is particularly desirable. By making the resin in such a range, it becomes easy not only to filter the flow of gelled ion generating resin to the outside after re-liquefaction, but also before gelled fuel is stored in the cartridge etc. It is also possible to remove only the auxiliary resin.

  When a gelling auxiliary resin is used as the gelling ion generator, its base strength is not particularly limited, and it may be a strongly basic anion exchange resin, a weakly basic anion exchange resin, a chelate resin, (The acid-base strength here is the same as that described above for the fuel gelled resin). Among these, a combination using a weakly acidic polymer electrolyte as the fuel gelling resin and a strongly basic ion exchange resin having the opposite polarity as the gelation auxiliary resin is preferable. The gelling auxiliary resin may be used alone, in combination with a plurality of resins, or in combination with other additives as long as it does not interfere with the gelation of methanol fuel.

  The amount of gelling ions that can coexist in the fuel composition is not particularly limited, but is in the range of 0.1 to 10 times the equivalent of neutralizing and reacting the functional group of the fuel gelling resin. Is preferable, and the range of 0.5 to 2 times is more preferable. By setting the amount of gelling ions in the above range, the pH of the fuel composition can be prevented from inadvertently increasing or decreasing due to the addition of gelling ions, and as a buffer solution during the reaction. Can be expected.

  The amount of the gelation auxiliary resin added is preferably an amount that generates reliquefied ions in a range of 0.1 to 10 times the equivalent of neutralizing and reacting the functional group of the fuel gelled resin. More preferably, it is an amount that generates reliquefied ions in the range of 0.5 to 2 times. The mass of the resin is derived from the required amount of reliquefied ions generated and the ion exchange capacity of the resin.

Next, the aspect of reliquefaction of methanol fuel gelled and stored as described above will be described.
As a method for reliquefying methanol fuel, for example, a method using heat, ultraviolet rays, external stimulation, or addition of a large amount of solution can be considered. However, in these re-liquefaction methods, the environment in which the fuel cell is used is wide. Therefore, for example, when the tank is broken, unintended stimulation may be applied to the methanol fuel, which is not preferable. A safer reliquefaction method is desired.
Accordingly, in the fuel storage gel of the present invention, reliquefied ions are allowed to coexist in the polymer electrolyte, salts thereof are formed, and the fuel gelled resin is contracted to reliquefy the fuel. However, other external stimuli or the like may be combined as long as the effects of the present invention are not hindered.

The reliquefied ions used in the fuel storage gel of the present invention will be described in more detail.
The polarity of the re-liquefied ions is not particularly limited. However, in order to reduce the degree of dissociation of the functional group of the polymer electrolyte, a polarity opposite to that of the functional group of the polymer electrolyte is desirable. That is, since a chaotic polymer electrolyte is used as a fuel gelled resin, katine is desirable as the reliquefied ion. Specific examples of reliquefied ions include cations such as sodium ion, potassium ion, lithium ion, ammonium ion, strontium ion, lead ion, barium ion, calcium ion, and zinc ion. Ammonium ions are preferred. (This is intentionally removed to differentiate it from proton-specific applications.)

  The amount of reliquefied ions generated in the gelled product is not particularly limited, but is preferably in the range of 0.1 to 10 times the equivalent of neutralizing the functional group of the fuel gelled resin, It is more preferable that the range be ˜2 times. Considering the use of gelling ions, it is preferably in the range of 0.1 to 10 times the equivalent of neutralizing both the functional groups and gelling ions of the fuel gelling resin, It is more preferable that the range be ˜2 times. By setting it as the said range, it is prevented that pH of a fuel composition raises carelessly or becomes low, and the effect as a buffer solution at the time of reaction can be anticipated.

  The viscosity of the re-liquefied methanol fuel is not particularly limited as long as it can be used for power generation, but is preferably 8 Pa · sec or less, and more preferably in the vicinity of the viscosity of methanol at 25 ° C. of 0.000108.

  The method for generating reliquefied ions in the gelled product is not particularly limited. For example, agents containing reliquefied ions (specifically, neutral salts, acidic salts, alkaline salts, polymer electrolyte resins, aqueous solutions thereof) And their methanol solutions). In particular, it is preferable to use an aqueous solution, a resin that generates reliquefied ions (hereinafter, referred to as “reliquefied ion generating resin”), and more preferably a reliquefied ion generating resin. By using the resin in this way, the resin portion after releasing the reliquefied ions without generating and diffusing counter ions of the reliquefied ions in the reliquefied fuel, as described in the gelation auxiliary resin. Can be separated and recovered as a solid. The reliquefied ions may be generated directly from the reliquefied ion generator or indirectly generated as in the case of gelling ions.

Although the kind of reliquefied ion generating resin is not specifically limited, From the point of the reliquefaction effect | action of reliquefied ion as mentioned above, the cationic resin of the same polarity as the polymer electrolyte in gelled material is used. In order to increase the reliquefaction efficiency, it is preferable to use a resin having a weaker polarity than the polymer electrolyte in the gelled product. Specifically, for example, when polyacrylic acid is used as the gelling resin, it is preferable to use a weak ammonium salt of an acidic chaotic exchange resin (for example, a chelate resin) as the reliquefied ion generating resin.
The molecular weight of the reliquefied ion generating resin is not particularly limited, but a mass average molecular weight of 100,000 to 10,000,000 is preferable, and 1,000,000 or more is more preferable. In particular, a crosslinked resin is preferred. By setting it as resin of such a range, it becomes easy to filter the loss of reliquefied ion generation resin to the outside after reliquefaction.

  The swelling strength of the reliquefied ion generating resin is not particularly limited, but is preferably lower than the swelling strength of the fuel gelled resin. By doing so, as described above for the gelation auxiliary resin, even when the fuel gelation resin swells, the swelling of the reliquefied ion generating resin is suppressed and kept in a certain shape. When removed, it can be easily separated from the fuel gelled product. Adjustment of the swelling strength of the resin, measurement method, and the like are the same as those described for the gelation auxiliary resin.

  The amount of the reliquefied ion generating resin is not particularly limited, but is an amount that generates reliquefied ions in a range of 0.1 to 10 times the equivalent of neutralizing and reacting the functional group of the fuel gelled resin. The amount is preferably such that the amount of reliquefied ions in the range of 0.5 to 2 times is generated. In consideration of the use of gelled ions, it is preferable that the amount is such that reliquefied ions in the above range are generated with respect to the equivalent of neutralizing and reacting both the functional group and gelled ions of the fuel gelled resin. . The mass of the resin is derived from the required amount of reliquefied ions generated and the ion exchange capacity of the resin.

  The mode of adding the reliquefied ion generating resin to the fuel gelled product is not particularly limited. Even if the reliquefied ion generating resin is added alone, the reliquefied ion generating resin is mixed with other compounds, and the mixture is used. It may be added to the gelled product. Among them, an aqueous solution in which reliquefied ion generating resin is mixed and reliquefied ions are contained in the liquid, a methanol solution in which reliquefied ion generating resin is mixed and reliquefied ions are contained in the liquid, or reliquefied ions. It is preferable to add a methanol aqueous solution in which the generated resin is mixed and the reliquefied ions are contained in the liquid to generate the reliquefied ions in the gelled product.

  Further, it is preferable to add a low-concentration methanol aqueous solution containing the reliquefied ion generating resin to the fuel gelled product, release the high-concentration methanol fuel as the fuel is taken out, and control the methanol concentration to supply the fuel cell. In a specific fuel cell, the concentration of methanol is diluted with water generated during power generation to obtain an optimal methanol concentration for the fuel cell. In such a fuel cell, when methanol with a high concentration is supplied at the time of startup, the power generation capacity may be reduced. By supplying low-concentration methanol at the time of startup, such a performance degradation can be prevented. Furthermore, methanol is supplied quickly during reliquefaction. At this time, the mixing ratio of the reliquefied ion generating resin and the low-concentration aqueous methanol solution is not particularly limited, but the reliquefied ion generating resin is preferably 10% by mass or less, and more preferably 1% by mass or less. The methanol concentration of the low-concentration methanol aqueous solution is not particularly limited, but is preferably 3% by mass or less, for example. The methanol concentration of the high-concentration methanol thus extracted is not particularly limited as long as it is higher than the concentration of the low-concentration methanol aqueous solution. Is preferred.

Next, specific examples of the resin material of the gelation auxiliary resin or reliquefied ion generating resin that can be used for the fuel storage gel of the present invention will be described. However, the present invention is not construed as being limited thereto.
In the fuel storage gel of the present invention, commercially available ion exchange resins can be used as the gelation auxiliary resin or reliquefied ion generating resin, and are classified as follows, for example.

ここで、基体とは高分子化合物の骨格をいい、例えば、スチレン系とは、スチレン骨格を有する高分子化合物を意味する。Ｉ型とは、ＩＩ型よりも塩基度がやや高い樹脂をいう。また、Ｉ型はＩＩ型より化学的に安定であり、交換吸着する力（イオンの選択性）が強いという特徴があり、Ｉ型を最強塩基性陰イオン交換樹脂ということもある。
ゲル型とは粒子内部が均一な架橋高分子で構成されているもので、もっとも一般的なものである。透明感のある外観をしており、粒子の内部は橋架けされた高分子が均一な網目状の構造となっており、この編目の隙間を通って水やイオン、溶質分子が粒子内部まで自由に拡散できる。
ポーラス型は粒子内部に微細な粗密構造を有するもので、高分子の編目以外に、イオンや分子の拡散を促進する細孔が存在する。
ハイポーラス型は細孔をさらに発達させた構造を持っており、反応速度が向上する。

Here, the substrate refers to a skeleton of a polymer compound. For example, styrene-based means a polymer compound having a styrene skeleton. Type I refers to a resin having a slightly higher basicity than type II. In addition, type I is chemically more stable than type II and has a strong exchange-adsorption force (ion selectivity), and type I is sometimes referred to as the strongest basic anion exchange resin.
The gel type is the most common type in which the inside of the particle is composed of a uniform crosslinked polymer. It has a transparent appearance, and the inside of the particles has a uniform network structure with bridged polymers, and water, ions, and solute molecules can freely pass through the gaps inside the particles. Can diffuse.
The porous type has a fine and dense structure inside the particle, and in addition to the polymer stitches, there are pores that promote the diffusion of ions and molecules.
The high porous type has a structure in which pores are further developed, and the reaction rate is improved.

  Below, the specific example of the repeating unit which has the functional group which comprises it about the ion exchange resin which can be used for the fuel storage gel of this invention is shown. Here, C-1 and C-2 are strongly acidic cation exchange resins, C-5 and C-6 are weakly acidic ion exchange resins, K-1 to K-3 are chelate resins, and A-1 and A-2 are Strongly basic anion exchange resins (A-1 is type I, A-2 is type II), and A-6 to A-8 are classified as weakly basic anion exchange resins. Although K-2 and A-7 have the same structural formula, the base strength can be changed by adjusting n in the formula, the number of functional groups in the molecule, etc., for example, reducing the total exchange capacity. Even if it is used as a chelate resin, it may be used as a weakly basic ion exchange resin by increasing the amount thereof.

The chelate resin may be coordinated with the central metal to form a complex, and the metal ions include Cr ³⁺ , In ³⁺ , Fe ³⁺ , Ce ³⁺ , Al ³⁺ , La ³⁺ , Hg ³⁺ , UO ²⁺ , Cu ²⁺ , VO ²⁺ , Pb ²⁺ , Ni ²⁺ , Cd ²⁺ , Cd ²⁺ , Zn ²⁺ , Co ²⁺ , Fe ²⁺ , Mn ²⁺ , Be ²⁺ , Ca ²⁺ , Mg ²⁺ , St ^{2+ and the} like.
The functional group of the resin can be used as desired by conditioning treatment or other treatment. In addition, some resin functional groups are described as metal ion salts, but they can be used as desired by conditioning treatment, if necessary.
In addition, the gelling auxiliary resin and the reliquefied ion generating resin preferably have a bead shape having a size that allows a ratio of passing through a mesh structure with an interval of 150 μm to be 20% or less, but a sheet shape, a fiber shape, or a powder shape It may be.

  Next, swelling (fuel storage) / shrinking (reliquefaction) embodiment examples of the fuel storage gel of the present invention (embodiment example in which a compound salt such as ammonium chloride is added to the fuel storage gel, ion exchange resin (hereinafter referred to as ammonium salt)) , Also referred to as “resin salt”) will be described in detail. However, the present invention is not construed as being limited thereby.

  When a compound salt containing reliquefied ions is added to an acidic polyelectrolyte in a methanol solution or aqueous solution and free cations (eg, ammonium ions) are generated and coexisted, the free cations are highly acidic (negative charge). Reacts with molecular electrolytes. The fuel storage gel for a fuel cell of the present invention utilizes such ion exchange action. At this time, as described above, instead of the compound salt containing the reliquefied ions, the aqueous solution containing the reliquefied ions by adding the resin salt, the methanol containing the reliquefied ions by adding the resin salt It is also preferable to use a solution or an aqueous methanol solution containing a reliquefied ion by adding a resin salt.

  The above ion exchange can be performed between ion exchange resins. For example, an acidic ion exchange resin that has become a free cation salt (for example, an ammonium salt) is added to a methanol-swelled gelled polymer electrolyte having a stronger acidity that has been protonated by conditioning treatment. Then, free cations are selectively substituted from the acidic ion exchange resin (resin salt) to a stronger acidic polymer electrolyte. By this ion exchange action, the fuel gelled resin shrinks and solidifies, and the methanol fuel is released, thereby realizing re-liquefaction of the fuel storage gel for fuel cells of the present invention.

This will be described more specifically with the following reaction scheme (however, the present invention is not limited thereto). In this exemplary scheme, the polyelectrolyte has a carboxyl group. This is swollen in methanol as a fuel gelled resin to form a gelled product (state 1). At this time, as described above, the gelled resin may not swell in methanol, such as when a high molecular weight absorbent is used to obtain a hard gel. In such a case, gelling ions may be generated in a mixture of methanol fuel and fuel gelling resin in the presence of a gelling auxiliary resin that assists swelling to promote swelling gelation. At this time, gelling ions having a polarity opposite to that of the polymer electrolyte are used. In this exemplary scheme, oxonium ions generated by a strongly basic ion exchange resin are used.
An ammonium salt of an acidic ion exchange resin that is weaker than the polymer electrolyte (a chelate resin ammonium salt is used in the present exemplary scheme) is added to the gelled product. Then, ammonium ions are substituted into the polymer electrolyte from the weaker acidic chelate resin. The polymer electrolyte in the form of an ammonium salt is insoluble in methanol, and the resin contracts to release methanol fuel (state 2).

In addition to the above-mentioned components, the fuel storage gel for fuel cells of the present invention does not affect the excellent properties, and in addition to the above-mentioned components, fragrances, pigments, corrosion inhibitors, discriminating agents, auxiliary agents, surfactants and the like are added. May be.
As the fragrance, for example, isoamyl formate, ethyl vanillin, citral, isoamyl propionate, 1-menthol, trans-2-butene, cis-2-butene and the like can be used. However, mercaptans and sulfides are not preferable because they contain sulfur, which not only contributes to environmental pollution but also degrades the catalyst used in the fuel cell. The pigment may be any of organic pigments, inorganic pigments, and dyes, and a fluorescent pigment may be blended. As the corrosion inhibitor, for example, dimer acid, polyoxyethylene alkylamine, carboxybetaine type amphoteric surfactant and the like can be used. The auxiliary combustor is preferably one having a high vapor pressure (for example, a vapor pressure higher than that of the fuel), and more preferably capable of generating electric power with the same mechanism or catalyst as the fuel. For example, organic acid, vitamin C Sodium borohydride, formic acid, etc. can be used. As a surfactant or a discriminating agent, for example, a substance described in JP-A No. 2001-93558 can be used.

Next, although the structural example of the fuel cell of this invention is given and the preferable embodiment of this invention is demonstrated, this invention is not limited by these.
FIG. 1 is a cross-sectional view schematically showing a preferred structural example of the fuel cell of the present invention. In FIG. 1, a fuel electrode 1 and an oxidant electrode 2 are provided on both sides via a separator 3, and a fuel chamber 4 and an oxidant chamber 5 are provided on the outer sides thereof. The oxidation of the methanol fuel is performed by flowing an oxidant (for example, oxygen or the like) through the oxidant chamber 5 (arrows 6a and 6b), and the oxidant is reduced. Arrow 7). The separator 3 preferably contains an electrolyte, and transmits ions (for example, hydrogen ions) well and does not transmit reactants (for example, hydrogen, methanol, oxygen, etc.). In this fuel cell, a filter medium 9 is provided outside the fuel electrode 1 so that impurities do not contact the fuel electrode 1. In the fuel cartridge for a fuel cell according to the present invention, the fuel chamber 4 in which the filter medium 9 and the fuel storage gel are put can be divided from other components of the fuel cell so as to be an exchange cartridge. It is preferable to use a filter medium as described above, whereby methanol fuel can be selectively injected into the battery body. Further, it is preferable to provide an ion removing filter instead of or together with this filter medium, and particularly to reduce the concentration of reliquefied ions mixed in the reliquefied methanol fuel to prevent deterioration of the fuel cell. At this time, an ion exchange resin is preferably used as the ion removal filter.

FIG. 2 is a sectional view schematically showing another preferred structural example of the fuel cell of the present invention. In this fuel cell, the fuel cell fuel storage gel in the fuel chamber is further divided into at least two or more compartments (cells) by a filter medium and stored in the fuel cell having the configuration shown in FIG. It is possible to generate electricity by re-liquefying the fuel gelled product of each cell as necessary.
Although there is no restriction | limiting in particular in the material of a filter medium, It is especially preferable that a molecular weight cut off is 10,000 or more. When the molecular weight cutoff of the filter medium is 10,000 or more, the filter medium is not clogged, and the power generation efficiency of the fuel cell is improved.

  Moreover, as a preferable embodiment using the fuel storage gel for a fuel cell of the present invention, a fuel storage and retrieval kit for a fuel cell in which at least the fuel storage gel (a) and the reliquefied ion generating resin (b) are combined is exemplified. In addition, a fuel storage / removal system that contains a fuel gelled resin composed of a polymer electrolyte and methanol fuel and swells and stores the fuel, or a reliquefied ion generator is added to the gelled product to reliquefy. Examples include a fuel cell fuel storage / extraction system that generates ions, reduces the degree of dissociation of the polymer electrolyte, contracts the fuel gelled resin, and releases and extracts methanol fuel.

EXAMPLES The present invention will be described in more detail with reference to examples below, but the present invention is not limited to these examples.
(Example 1)
As a fuel gelled resin, a polymer absorbent that is a crosslinked polyacrylic acid (Nippon Catalyst, Aquaric CA-H2 (trade name) (Nippon Catalyst measurement particle size 850 μm-ON 20% or more, 150 μm-thru 20% or less)) Using. The form used was powdery. As a pretreatment, cations bonded to the polymer absorbent in the initial state were removed as follows. The polymer absorbent was packed in a column, and a sufficient amount of 2N hydrochloric acid was passed through the column to release cations (conditioning treatment). Furthermore, hydrochloric acid remaining in the column was poured out with a sufficient amount of purified water to remove ions. Since the polymer absorbent from which ions were removed was swollen, it was dried at room temperature.

  Next, a gelling auxiliary resin for assisting the swelling of the polymer absorbent was prepared. As the gelling auxiliary resin, strongly basic anion exchange resin PA308 (trade name) manufactured by Mitsubishi Chemical Corporation was used. The form used was a bead. Since the strongly basic anion exchange resin is a sodium salt, a conditioning treatment for removing sodium ions was performed. Conditioning utilized 2N sodium hydroxide. The strongly basic anion exchange resin after conditioning was dried at room temperature.

0.08 g of strongly basic ion exchange resin was added to 0.08 g of the polymer absorbent subjected to the conditioning treatment, and 7 ml of methanol was added and swollen to prepare a fuel storage gel for a fuel cell of the present invention. The obtained gelled product was a hard gel.
When 0.08 g of ammonium chloride was added as a reliquefied ion generator to the resulting fuel cell fuel storage gel, methanol fuel reliquefaction was completed in about 10 minutes. The amount of methanol taken out by the dropper was 80% by mass or more (fuel removal yield) with respect to the added methanol. At this time, the reliquefied methanol was separated from the solid impurities and easily taken out.

(Example 2)
A weakly acidic chelate ion-exchange resin (manufactured by Mitsubishi Chemical Corporation, CR11 (trade name) mass average molecular weight) was used as a reliquefied ion generator added for reliquefaction. The form used was a bead. In addition, since this weakly acidic chelate resin is a sodium salt in the initial state, a conditioning treatment for removing sodium ions was performed. 2N hydrochloric acid was used for conditioning. This is washed with water and then immersed in aqueous ammonia to form a weak acidic chelate resin ammonium salt, which is dried at room temperature.

  When 0.24 g of the weak acidic chelate resin ammonium salt was added to the fuel storage gel prepared in Example 1, the re-liquefaction of methanol fuel was completed in about 8 hours. The amount of methanol taken out by the dropper was 75% by mass or more (fuel removal yield) with respect to the added methanol. At this time, the re-liquefied methanol was easily extracted by being separated from solid impurities by suppressing the mixing of by-products.

It is sectional drawing which shows typically the preferable structural example of the fuel cell of this invention. It is sectional drawing which shows typically another preferable structural example of the fuel cell of this invention.

Explanation of symbols

1 Fuel Electrode 2 Oxidant Electrode 3 Separator 4 Fuel Chamber (Fuel Storage Gel Storage Chamber)
5 Oxidant chamber 6a, 6b Flow direction of oxidant
7 Current flow direction 9 Filter material

Claims (22)

  A fuel storage gel comprising a fuel gelled resin composed of a cationic polymer electrolyte and methanol fuel to be swollen and gelled, wherein reliquefied ions are generated by adding a reliquefied ion generator, and the reliquefied ions And the polymer electrolyte coexist to form a salt of both, and the fuel gelled resin can be shrunk to release the methanol fuel in the gelled product.   The fuel storage gel for a fuel cell according to claim 1, wherein a reliquefied ion generating resin is added to the fuel storage gel as a reliquefied ion generator to generate reliquefied ions in the gelled product.   The fuel storage gel for a fuel cell according to claim 1 or 2, wherein the reliquefied ions are ammonium ions.   The fuel storage gel for a fuel cell according to any one of claims 1 to 3, wherein the reliquefied ions are cations generated in the gelled product by adding a reliquefied ion generating resin to the gelled product.   The fuel storage gel for a fuel cell according to any one of claims 2 to 4, wherein the reliquefied ion generating resin is a salt of reliquefied ions.   An aqueous solution, a methanol solution, or an aqueous methanol solution containing reliquefied ions in a liquid by a reliquefied ion generating resin is added to the gelled product to generate reliquefied ions in the gelled product. 6. The fuel storage gel for a fuel cell according to any one of 5 above.   The fuel according to any one of claims 1 to 6, wherein the re-liquefied ion generator comprises at least one resin selected from the group consisting of a strong acid cation exchange resin, a weak acid cation exchange resin, and a chelate resin. Fuel storage gel for batteries.   The said reliquefaction ion generator is a gel-like resin, and consists of at least 1 resin chosen from the group which consists of a strong acid cation exchange resin, a weak acid cation exchange resin, and a chelate resin. The fuel storage gel for fuel cells according to 1.   The fuel storage gel for a fuel cell according to any one of claims 1 to 8, wherein the cationic polymer electrolyte is at least one selected from the group consisting of polyacrylic acid and a crosslinked polyacrylic acid.   The fuel storage gel for a fuel cell according to any one of claims 1 to 9, wherein the gelled product is a ring gel or a double network gel. A gelled fuel (a) containing a fuel gelled resin composed of a cationic polymer electrolyte and a methanol fuel and storing the fuel by gelling, and a reliquefied ion generating resin (b)
A fuel storage and retrieval kit combining at least
A reliquefied ion generating resin (b) is added to the gelled fuel (a) to generate reliquefied ions in the gelled product, and the reliquefied ions coexist with the polymer electrolyte to form a salt of both. A fuel storage and removal kit for a fuel cell, wherein the fuel gelled resin is shrunk to release methanol fuel. A fuel storage and extraction system that contains a fuel gelled resin made of a cationic polymer electrolyte and methanol fuel to gel and store the fuel,
A reliquefied ion generator is added to the gelled product to generate reliquefied ions, the reliquefied ions and the polymer electrolyte coexist to form a salt of both, and the fuel gelled resin is shrunk to methanol A fuel storage and retrieval system for a fuel cell capable of releasing fuel. (A) A fuel gelled resin comprising a cationic polymer electrolyte and a methanol fuel are contained to swell and gelate, and the fuel is stored.
(B) A reliquefied ion generating resin is added to the gelled product to generate reliquefied ions in the gelled product, and the reliquefied ions and the polymer electrolyte coexist to form both salts, A fuel storage and retrieval system for a fuel cell in which the fuel gelled resin is shrunk to release methanol fuel.   The fuel storage and extraction system for a fuel cell according to claim 12 or 13, wherein the concentration of reliquefied ions contained in the released fuel is reduced by a filter.   The fuel storage / extraction system for a fuel cell according to claim 14, wherein the filter is a filter provided with an ion exchange resin.   In order to store a fuel gelled resin composed of a cationic polymer electrolyte and a methanol fuel to swell and gel the fuel, a reliquefied ion generator is added to the gelled product to generate reliquefied ions, A fuel storage method for a fuel cell, wherein a methanol fuel is gelled and stored so that a polymer electrolyte and reliquefied ions can coexist to form a salt of both, and the fuel gelled resin is contracted to release the fuel. (A) A gelled product containing a fuel gelled resin composed of a cationic polymer electrolyte and methanol fuel to swell and store the fuel,
(B) A reliquefied ion generating resin is added to the gelled product to generate reliquefied ions, the reliquefied ions and the polymer electrolyte coexist to form a salt of both, and the fuel gelled resin is A fuel take-out method for a fuel cell that is contracted to release and take out fuel.   The low-concentration methanol aqueous solution containing the re-liquefied ion generating resin is added to the gelled product to gradually release the highly concentrated methanol, and the methanol concentration is controlled and taken out and supplied to the fuel cell. Fuel cell fuel extraction method.   A fuel cartridge for a fuel cell, comprising at least the fuel storage gel for a fuel cell according to any one of claims 1 to 10 and an ion removal filter.   20. A fuel cartridge for a fuel cell, wherein the fuel cartridge for a fuel cell according to claim 19 and at least a reliquefied ion generating resin are combined to form a kit.   A fuel cell comprising at least the fuel cartridge for a fuel cell according to claim 19 or 20. A portable device comprising the fuel cell according to claim 21.

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