JP2001093558A - Fuel composition for fuel cell - Google Patents

Abstract

(57) [Problem] To provide a fuel composition for a fuel cell, which can shorten the startup time of the fuel cell. The present invention provides a fuel composition for a fuel cell, comprising a fuel containing an alcohol having 3 or less carbon atoms and water, and a surfactant.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a fuel composition for a methanol fuel cell, and more particularly to a fuel composition for a fuel cell which supplies fuel by capillary force.

[0002]

2. Description of the Related Art Various types of fuel cells are known, such as a fuel vapor supply type and a type utilizing capillary force.
Fuel prepared by mixing alcohol and water is used as the fuel.

Conventional fuel vaporization type fuel cells can directly use high-concentration fuel, which is advantageous in terms of making the fuel section compact. However, since the system is complicated, the size of the fuel cell can be reduced as it is. It has the problem of being difficult. On the other hand, the conventional liquid fuel cell utilizing the capillary force is suitable for miniaturization in terms of configuration, but the fuel is supplied directly to the fuel electrode in a liquid state, so that a low-concentration fuel must be used. Therefore, as a result, the volume of the fuel section becomes large, and it is difficult to reduce the size.

A new type of fuel cell that solves such a problem is disclosed in Japanese Patent Application Laid-Open No. H11-162630. This fuel cell has a structure in which a liquid fuel as a fuel is introduced into each unit cell by capillary force, vaporized in each unit cell, and the vaporized fuel is supplied to a fuel electrode. Therefore, high-concentration fuel can be used without using an auxiliary device such as a fuel vaporizer or the like, so that downsizing is possible.

However, even in such a new type of battery, the shortening of the startup time and the startup from a low temperature, which have been problems in the conventional liquid fuel cell, are extremely serious obstacles to practical use as a small power source. .

[0006]

In the case of a fuel supply system utilizing the capillary phenomenon of a perforated plate, as in the above-mentioned new type of battery, the wettability between the capillary and the fuel is a major problem. Further, when such a new battery is started from a low temperature (the outside air temperature is equal to or lower than the room temperature), the fuel vaporization by the porous vaporization layer becomes difficult to occur, and the vapor pressures of methanol and water are greatly reduced. Therefore, even if heating is performed by the heater, a long time is required for starting the battery, and the starting time cannot be reduced. On the other hand, when such a fuel cell is used at a low temperature (40 ° C. to room temperature below the freezing point), fluidity due to freezing of the fuel itself and an increase in viscosity becomes a problem.

[0007] On the other hand, since a commonly used fuel is colorless and transparent, it is difficult to easily visually confirm the use condition of the fuel. In the event that such fuel leaks, it is difficult to understand because it is transparent, and there is a risk of causing danger because the fuel component contains alcohol.

The present invention has been made to solve the above-mentioned problems in the conventional fuel cell and to provide a fuel for a small fuel cell which is useful as a power source for a small device. It is an object of the present invention to provide a fuel composition for a fuel cell, which can shorten the time.

[0009]

In order to solve the above-mentioned problems, the present invention provides a fuel composition for a fuel cell, comprising a fuel containing an alcohol having 3 or less carbon atoms and water, and a surfactant. I do.

Hereinafter, the present invention will be described in detail.

First, a new alcohol fuel cell using the fuel composition of the present invention will be described.

FIG. 1 is a schematic diagram showing the structure of such an alcohol fuel cell. As shown in the figure, this fuel cell basically includes a stack body 1, a fuel tank 2, and an introduction pipe 3 for supplying liquid fuel from the fuel tank to the body.

In the stack body 1, a permeation plate 4 is arranged between the cells 11, a permeable membrane 5 capable of taking in air from outside, and a receiver for receiving the liquid fuel supplied from the introduction pipe 3. 6 are provided. Further, a fan (not shown) is provided on a side surface of the stack body 1 to supply an oxidizing gas. The fuel tank 2 is provided with a liquid storage section 7 for storing fuel, a core body 8 provided therein, and a permeable membrane 9 capable of taking in air from the outside. The core body 8 is connected to the introduction pipe 3 at a junction 10.

In such a fuel cell, liquid fuel as fuel is introduced into each unit cell 11 by capillary force, vaporized in each unit cell, and the vaporized fuel is supplied to the fuel electrode. As described above, the liquid fuel is introduced into each unit cell by capillary force, and thus the fuel cell shown does not require a driving unit such as a pump for supplying fuel. The liquid fuel introduced into the cell is vaporized in the fuel vaporization layer using the reaction heat of the cell reaction, and therefore does not require an auxiliary device such as a fuel vaporizer. Also, since the gaseous fuel in the fuel vaporization layer is kept substantially saturated, the liquid fuel is vaporized from the fuel permeation layer by the amount of gaseous fuel consumed in the fuel vaporization layer by the cell reaction, and the liquid fuel is further vaporized Is introduced into the cell by capillary force.

As described above, in the fuel cell shown in the drawing, since the fuel supply amount is linked to the fuel consumption amount, almost no unreacted fuel is discharged out of the cell, as in the conventional liquid fuel cell. Does not require a treatment system on the fuel outlet side. That is, the fuel cell shown in FIG. 1 is a new type of liquid fuel that does not require the use of auxiliary devices such as a pump, a blower, a fuel vaporizer, and a condenser.

In such a fuel cell, in order to achieve the introduction of liquid by capillary action, a porous base material capable of causing capillary action is used. Although it depends on the type of the material, the liquid fuel consisting only of the alcohol aqueous solution does not sufficiently penetrate into the base material. The present inventors improve the wettability between the liquid fuel and the capillary inside the perforated plate by adding a surfactant to the liquid fuel composed of the alcohol aqueous solution, and easily perform the suction of the fuel by the capillary phenomenon. It has been found that fuel supply can be improved.

In the fuel composition of the present invention, the fuel is composed of alcohol having 3 or less carbon atoms and water. Examples of the alcohol having 3 or less carbon atoms include methanol, ethanol, isopropanol, and 1-propanol. The content of the alcohol is preferably 1% by weight or more and 80% by weight or less, more preferably 10% by weight or more and 40% by weight or less based on the whole fuel composed of alcohol and water. Alcohol content is 1wt%
If it is less than 1, the fuel tank becomes too large, and it is difficult to reduce the size. If it exceeds 80 wt%, water as the other component of the fuel is reduced, so that the cell reaction may not easily occur.

The content of water, which is the other component of the fuel, can be appropriately determined according to the amount of the alcohol.

As the surfactant incorporated in the fuel composition of the present invention, any of an ionic (cationic, anionic, amphoteric) surfactant and a nonionic (nonionic) surfactant can be used. Often, they can be used alone or as a mixture of two or more.

The following are specific examples of the surfactant which can be used in the present invention, but the present invention is not limited to these.

Examples of the anionic surfactant include alkylsulfonic acid and salts thereof, alkylbenzenesulfonic acid and salts thereof, polyoxyalkylenesulfonic acid and salts thereof perfluoroalkylsulfonic acids and salts thereof, perfluoroalkylbenzenesulfonic acids and salts thereof. Salt thereof, perfluoropolyoxyalkylenesulfonic acid and its salt, polystyrenesulfonic acid and its copolymer, polyvinylsulfonic acid and its copolymer, polyperfluorovinylsulfonic acid and its derivative, polyacrylic acid and its copolymer And the like.

Examples of the cationic surfactant include polymers having a quaternary ammonium group such as alkyltrimethylammonium halide and higher alkane derivatives.

As the amphoteric surfactant, a sulfonic acid group
(RSO_Three ^-) And a quaternary ammonium group (R_FourN⁺)
Polymer and higher alkane derivative (s
Betaine rufonic acid) and carboxyl group (RCOO-)
And a quaternary ammonium group (R _FourN⁺) In the molecule
Polymers and higher alkane derivatives (betaines)
No.

Nonionic surfactants include alkylsulfonic acid esters, alkylbenzenesulfonic acid esters, polyoxyalkylenes and their copolymers, polyoxyalkylenesulfonic acid esters, perfluoroalkylsulfonic acid esters, perfluoroalkylbenzenesulfonic acids. Acid ester, perfluoropolyoxyalkylene and its copolymer, perfluoropolyoxyalkylenesulfonic acid ester, polystyrenesulfonic acid and its copolymer, polyperfluorovinylsulfonic acid ester and its copolymer, and polyacrylic acid Examples include esters and copolymers thereof.

As the surfactant particularly preferably used in the present invention, specifically, polyoxyethylene,
Florard at the time of fluorine-based surfactant (3M), 2nd
Higher alcohol ethoxysulfone, alkyl benzene sulfonate, alkyl sulfosuccinate, polyoxyethylene alkyl ether carboxylate, polyoxyethylene alkyl phenyl ether, and the like.

The amount of such a surfactant to be added to the fuel composition of the present invention is from 1 ppm to 5 ppm based on the whole composition.
%, Preferably from 10 ppm to 0.1%.
% (1000 ppm). 1pp
If it is less than m, the effect of adding the surfactant cannot be obtained. On the other hand, if it exceeds 5%, bubbles and the like may be trapped and hinder the introduction of fuel by the capillary.

The fuel composition of the present invention may be blended with a pigment (dye or pigment) as a discriminating agent to color the fuel. By adding such a discriminating agent, it is possible to visually check whether the fuel is used or there is no fuel leakage.

The dye may be either an organic pigment or an inorganic pigment. As the dye, a water-soluble dye and an alcohol-soluble dye can be used. Further, in the present invention, a fluorescent dye may be blended as the dye.

Specific examples of dyes that can be used are shown below, but are not limited thereto. As a pigment,
Examples thereof include carbon, quinacridone, and phthalocyanine. Examples of dyes include indigo, azo dyes, triphenylmethane dyes (eg, magenta), and xathene dyes (eg, phenolphthalein and rhodamine).

The fluorescent dye may be either inorganic or organic. Examples of the inorganic dye include sulfides such as calcium sulfide and zinc sulfide and derivatives thereof, oxides such as yttrium oxide, magnesium tungstate, and zinc silicate. And oxyacid salts such as barium silicate.
On the other hand, examples of organic fluorescent dyes include anthraquinone dyes, polymethine dyes, dithiol metal salt dyes, indophenol dyes, and xanthene dyes.

When any of the above-mentioned dyes that do not dissolve in the fuel composition is added to the fuel composition of the present invention, a dispersion is prepared in advance using a dispersant as a dispersion, and then dispersed in the fuel composition. Can be used. On the other hand, what is dissolved in the fuel composition may be dissolved in the fuel composition or its component in a predetermined amount as it is.

The amount of the pigment incorporated in the fuel composition of the present invention as a discriminating agent is 0.01 to 0.01% by weight of the fuel composition.
The content is preferably from 1 ppm to 10000 ppm, more preferably from 0.1 ppm to 100 ppm. If it is less than 0.01 ppm, it is difficult to confirm it visually, and if it exceeds 10,000 ppm, it is considered that the electrode reaction and the fuel supply are adversely affected. If the added dye may adversely affect fuel supply (wetting) or electrode reaction by the capillary tube, a filter and a dye adsorption layer are provided at the outlet of the fuel tank or the inlet of the fuel permeation plate. I just need.

In the fuel cell as shown in FIG.
At low temperatures, the vaporization of fuel in the fuel vaporization layer in the fuel cell is unlikely to occur, so that the vapor pressure of alcohol or water of the fuel becomes very small. In this case, it becomes difficult to supply a sufficient amount of fuel to the electrode. In order to avoid such inconveniences, by adding a fuel (combustion agent) having a high vaporization ability even at a low temperature, that is, a high vapor pressure, a low-temperature start-up and a shortening of the start-up time can be made possible.

As the auxiliary agent used in the present invention, there are two types of substances, ie, a substance which substitutes for alcohol which is one component of fuel, and a substance which substitutes for water which is the other component of fuel.

As a substance which can be substituted for the alcohol which is the first auxiliary agent, alkyl ether having 3 or less carbon atoms,
Aldehydes, alkyl formate, and oxalate are exemplified. These can be used alone or as a mixture of two or more.

In the anode, since the water in the fuel is used to oxidize methanol to carbon dioxide, the above-mentioned substance that substitutes for water is used as the second combustion aid. Examples of such substances include substances that can supply oxygen atoms, such as alkyl nitrates, organic nitro compounds, nitroso compounds, and organically modified oxides. These can be used alone or as a mixture of two or more.

Specific examples of the flame retardant include ethers such as dimethyl ether, methylal and 1,2-dimethoxytan; aldehydes such as formaldehyde, acetaldehyde, glyoxal and glycolaldehyde; methyl formate, ethyl formate, Formate esters such as isopropyl formate and n-propyl formate; oxalate esters such as dimethyl oxalate, diethyl oxalate and ethyl methyl oxalate; nitrate esters such as methyl nitrate and ethyl nitrate; nitro compounds such as nitromethane and nitroethane;
Organic peroxides such as, but not limited to, methyl hydroperoxide, t-butyl hydroperoxide, dimethyl peroxide, peracetic acid, and formic acid.

It is preferable that one or more of the above-mentioned first and second flame retardants are selected and used in combination.

Further, fuel is supplied by using a capillary phenomenon,
In a fuel cell of a type in which a gas is vaporized in a vaporization layer, it is desired that the final product of the auxiliary agent generated by the electrode reaction be gasified in consideration of the fact that the product of the electrode reaction of the auxiliary agent remains. Examples of the auxiliary agent that gasifies the final product of the electrode reaction include dimethyl ether, methylal, formaldehyde, methyl formate, methyl oxalate, methyl nitrate, nitromethane, methyl hydroaloxide,
Formic acid and the like can be mentioned.

The content of the above-mentioned auxiliary agent is preferably in the range of 0.001% to 50% with respect to the whole fuel composition. When the content is less than 0.001%, it is difficult to obtain a sufficient effect, and when the content is more than 50%, the solubility in water is reduced and the liquid may be separated.

The fuel composition of the present invention may be prepared by introducing oxygen and irradiating with ultraviolet rays to cause a reaction.
Peroxide is generated by introducing oxygen and irradiating with ultraviolet rays. The peroxide thus obtained reacts with a fuel such as alcohol at the anode electrode and acts as a substitute for water, and is therefore preferable in terms of starting the battery at a low temperature.

In some cases, the operation of introducing oxygen and irradiating ultraviolet rays may be performed before adding a surfactant. First, a fuel may be prepared by mixing alcohol and water, oxygen may be introduced into the fuel, and the fuel may be irradiated with ultraviolet rays to cause a reaction, and then a predetermined surfactant may be added. In particular, when the surfactant is easily decomposed into ultraviolet rays, it is desired to prepare the fuel composition by such a procedure.

The fuel composition of the present invention may contain volatile organic and inorganic acids, iodine and iodine compounds as components for accelerating the electrode reaction.

The acid acts as a reaction accelerator because it can reduce the overvoltage of alcohol oxidation in the electrode reaction. Acids that can be used include, for example, acetic acid,
Examples include, but are not limited to, methanesulfonic acid, trifluoromethanesulfonic acid, hydrochloric acid, and trifluoroacetic acid.

In the case of iodine and iodine compounds, iodine ions act catalytically in the electrode reaction to accelerate the reaction.
Specific examples of the compound include, but are not limited to, iodine compounds such as methane iodide and ethane iodide.

When the amount of alcohol contained in the fuel composition of the present invention exceeds 30% by weight of the whole fuel, it does not freeze even at a low temperature (40 ° C. below freezing point). When the amount of alcohol is 30 wt% or less, an antifreezing agent or a fluidity improver is blended,
It is desired to make the fuel composition antifreeze.

The antifreezing agent and the fluidity improver include
Polyhydric alcohols and derivatives thereof can be used, and the added amount is 0.1% to 10% with respect to the fuel.
It is preferable to be within the range. If it is less than 0.1%, it is difficult to obtain a sufficient effect, and if it exceeds 10%, the fluidity of the fuel may be reduced.

Examples of polyhydric alcohols and derivatives thereof include ethylene glycol, diethylene glycol, glycerin, propylene glycol, ethylene glycol monomethyl ether, diglyme, oligomers of polyoxyethylene, and oligomers of polyoxypropylene. It is not limited to.

In addition to the above-mentioned components, the fuel composition of the present invention may further contain a fragrance, a corrosion inhibitor and the like. As the fragrance, for example, isoamyl formate, ethyl vanillin, citral, isoamyl propionate, l-menthol and the like can be used. Further, as the corrosion inhibitor, for example, dimer acid, polyoxyethylene alkylamine, carboxybetaine type amphoteric surfactant and the like can be used.

In consideration of safety, it is desirable to ensure safety when the fuel tank is broken or when the fuel tank is carried. In addition, when the fuel tank is used in a place where the temperature is high, the vapor pressure of the liquid fuel becomes high, so that the tank may be pressurized, which may cause danger.

Such a danger can be avoided by gelling the above-described fuel composition of the present invention into a gel-like fuel composition.

Gelation for obtaining a gel fuel composition is carried out by:
This can be achieved by a method (chemical gel) in which fuel is absorbed by an organic polymer. Alternatively, the fuel composition may be gelled by using a method (physical gel) using thixotropic property due to interaction (hydrogen bonding or the like) by mixing the fuel liquid and the particle powder.

Specific examples of the organic polymer as the gelling agent for the chemical gel include cross-linked polyacrylic acid and derivatives thereof,
Examples include, but are not limited to, cross-linked polyacrylamide and its derivatives.

As the cross-linking agent for the physical gel, any substance can be used as long as it causes a hydrogen bond with the fuel composition. Specifically, for example, activated carbon, inorganic oxides such as aerosil, organic amide derivatives and the like,
It is not limited to these.

The gelling agent is used in an amount of 1 to the fuel composition weight.
It is preferable to add in the range of 100 parts by weight to 100 parts by weight. The gelled fuel composition has a high vapor pressure at high temperatures and a large increase in viscosity due to the interaction between the fuel liquid and the gelling agent. For this reason, it is possible to prevent the liquid from scattering when the tank is broken, which leads to an improvement in safety.

The gel fuel composition can be used, for example, in a fuel cell having a structure as shown in FIG. In the fuel cell shown in FIG. 2, the gel fuel composition 12 is attached to the stack body 2 by the gel holding material 13. The configuration of the stack body 2 is the same as that of the fuel cell shown in FIG.

[0057]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in more detail with reference to specific examples.

Example 1 First, 0.01 g of perfluoroalkylpolyoxyethylene ethanol (Fluorad FC-170C, manufactured by Sumitomo Shiriem Co., Ltd.) as a surfactant was dissolved in 50 g of methanol. Further, 50 g of ion-exchanged water was added to obtain a fuel composition of Example 1.

One end of a carbon porous plate (manufactured by Nippon Carbon Co., Ltd.) was immersed in this fuel composition, and a penetration test was carried out. As a result, the permeation of the porous plate was visually confirmed. The permeation could be visually confirmed, indicating that the fuel cell can be started in a very short time by using the fuel composition of this example.

Comparative Example 1 A fuel comprising 50 g of methanol and 50 g of ion-exchanged water was prepared. This fuel corresponds to a conventionally used fuel. When a permeation test was carried out on the obtained fuel in the same manner as in Example 1 described above, almost no permeation occurred. Therefore, it is presumed that when this fuel is used, it takes a long time to start the fuel cell.

(Example 2) First, 0.01 g of perfluoroalkylpolyoxyethylene ethanol (Fluorard FC-170C, manufactured by Sumitomo Shiriem Co.) as a surfactant was dissolved in 50 g of methanol. 50 g of ion-exchanged water is added to this solution, and a red dye (CI No. 16045, manufactured by Daiwa Kasei Co., Ltd.) is used as a discriminating agent.
1 mg was added to prepare a colored fuel composition.

The resulting fuel composition had a uniform and very distinct red coloration. When a penetration test was performed on this fuel composition in the same manner as in Example 1, it was visually confirmed that the fuel composition permeated the perforated plate. This indicates that the fuel cell can be started in a very short time by using the fuel composition of this example.

Example 3 1 g of butyral resin as a dispersant was dissolved in 45 g of methanol, and 5 g of phthalicyanine, a blue pigment as a discriminating agent, was added to prepare a pigment dispersion by a sand mill.

On the other hand, a perfluoroalkylpolyoxyethylene ethanol (Florade FC-170C manufactured by Sumitomo Shiriem Co., Ltd.) as a surfactant was added to 50 g of methanol.
0.01 g was dissolved to obtain a solution, and 0.01 g of the above-described pigment dispersion and 50 g of water were added to prepare a colored fuel composition.

The resulting fuel composition had a uniform and very clear blue coloration. When a penetration test was performed on this fuel composition in the same manner as in Example 1, it was visually confirmed that the fuel composition permeated the perforated plate. This indicates that the fuel cell can be started in a very short time by using the fuel composition of this example.

Example 4 First, 0.01 g of perfluoroalkylpolyoxyethylene ethanol (Fluorad FC-170C, manufactured by Sumitomo Shiriem Co.) as a surfactant was dissolved in 50 g of methanol. Next, 50 g of ion-exchanged water was added to this solution, and 1 mg of a yellow dye (CI acid yellow 7) as a discriminating agent was further added.
In addition, a colored fuel composition was prepared.

The resulting fuel composition was uniformly and very distinctly colored and emitted green fluorescence. When a penetration test similar to that of Example 1 was performed for this fuel composition,
The permeation of the perforated plate was visually confirmed. From this, by using the fuel composition of this example,
It can be seen that the fuel cell can be started in a very short time.

Example 5 First, 1 g of methyl formate and 1 g of methyl nitrate as a combustion aid were added to a mixed solution of 50 g of methanol and 50 g of ion-exchanged water. Further, 0.01 g of perfluoroalkyl polyoxyethylene ethanol (Fluorad FC-170C manufactured by Sumitomo Shiriem Co., Ltd.) as a surfactant was dissolved to prepare a fuel composition of this example.

Using this fuel composition, a start-up test of the fuel cell shown in FIG. 1 was performed at 0 ° C., and it was confirmed that the cell started normally.

(Comparative Example 2) A fuel cell startup test was performed in the same manner as in Example 5 using a mixed solution of 50 g of methanol and 50 g of ion-exchanged water, but the fuel cell was not started.

Example 6 First, 1 g of dimethyl ether and 1 g of methyl nitrate as a combustion aid were added to a mixed solution of 50 g of methanol and 50 g of ion-exchanged water. Further, 0.01 g of perfluoroalkylpolyoxyethylene ethanol (Fluorard FC-170C manufactured by Sumitomo Shiriem Co., Ltd.) as a surfactant was dissolved to prepare a fuel composition of this example.

Using the fuel composition, a start-up test of the fuel cell shown in FIG. 1 was conducted at 0 ° C., and it was confirmed that the cell started normally.

Example 7 First, to a mixed solution of 50 g of methanol and 50 g of ion-exchanged water were added formaldehyde as a combustion aid and 1 g of t-butyl peroxide. Further, a perfluoroalkyl polyoxyethylene ethanol (Fluorad FC-17) as a surfactant is used.
0.01C (manufactured by Sumitomo Silica Corporation) was dissolved to prepare a fuel composition of this example.

Using the fuel composition, a start-up test of the fuel cell shown in FIG. 1 was conducted at 0 ° C., and it was confirmed that the cell started normally.

Example 8 A high-pressure mercury lamp was irradiated to a mixed solution of 50 g of methanol and 50 g of ion-exchanged water while bubbling by introducing air to cause a reaction.
Thereafter, 0.1 g of polyethylene glycol (manufactured by Merck) as a surfactant was added to prepare a fuel composition of this example.

Using the fuel composition, a start-up test of the fuel cell shown in FIG. 1 was performed at 0 ° C., and it was confirmed that the cell started normally.

Example 9 To a mixed solution of 20 g of methanol and 80 g of ion-exchanged water, 10 g of ethylene glycol as an antifreezing agent was added, and 0.05 g of Florad FC93 (manufactured by 3M) as a surfactant was added. hand,
A fuel composition of this example was prepared.

After cooling the obtained fuel composition,
It did not freeze even at 30 ° C. Therefore, it can be seen that the fuel composition of this example can start the fuel cell even at a low temperature of -30 ° C.

(Comparative Example 3) A mixed solution of 20 g of methanol and 80 g of ion-exchanged water was prepared, and the mixed solution was cooled and frozen at about -10 ° C.

As described above, the conventional fuel cannot start the fuel cell under the condition of about −10 ° C.

(Example 10) To a mixed solution of 30 g of methanol and 60 g of ion-exchanged water, 10 g of ethylene glycol as an antifreezing agent was added, and a red dye (CI No. 16045, Daiwa Kasei Co., Ltd.) as a discriminating agent was added. Made)
1 mg was added for coloring. Further, a perfluoroalkyl polyoxyethylene ethanol (Fluorard FC-170C manufactured by Sumitomo Silica M) as a surfactant was added.
01 g was dissolved to prepare a fuel composition of this example.

The resulting fuel composition was uniformly and very distinctly colored red. When this fuel composition was cooled, it did not freeze even at a low temperature of -40 ° C. Therefore, the fuel composition of the present example is at −40 ° C.
However, it can be seen that the fuel cell can be started.

Example 11 First, 1 g of methyl formate and 1 g of methyl nitrate as a combustion promoter were added to a mixed solution of 50 g of methanol and 50 g of ion-exchanged water. further,
Red dye as a discriminating agent (CI No. 16045,
1 mg of Daiwa Kasei Co., Ltd.) was added for coloring, and 0.01 g of perfluoroalkylpolyoxyethylene ethanol (Fluorad FC-170C manufactured by Sumitomo Shiriem Co., Ltd.) as a surfactant was added to prepare a fuel composition of this example. .

The resulting fuel composition had a uniform and very distinct red coloration. A start-up test of the fuel cell shown in FIG. 1 was performed at 0 ° C. using this fuel composition, and it was confirmed that the fuel cell started normally.

Example 12 First, 0.01 g of perfluoroalkylpolyoxyethylene ethanol (Fluorad FC-170C, manufactured by Sumitomo Shiriem Co.) as a surfactant was dissolved in 50 g of methanol. Next, 50 g of ion-exchanged water was added to obtain a fuel composition of this example.
Further, 5 g of a gelling agent (cross-linked polyacrylic acid) was added and stirred to obtain a gel fuel composition.

Using the obtained gel fuel composition, FIG.
When the fuel cell shown in (1) was started, it was confirmed that the fuel cell started normally.

[0087]

As described above, according to the present invention, there is provided a fuel composition for a fuel cell capable of shortening the startup time of the fuel cell.

By using the fuel composition of the present invention, not only the start-up time of the liquid fuel cell can be shortened, but also such a fuel cell can be started from a low temperature. Furthermore, the fuel composition of the present invention is also excellent in terms of safety because it can be visually identified and confirmed,
Its industrial value is enormous.

[Brief description of the drawings]

FIG. 1 is a schematic diagram illustrating a configuration of an example of a fuel cell started with the fuel composition of the present invention.

FIG. 2 is a schematic diagram showing the configuration of another example of a fuel cell started with the fuel composition of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Stack body 2 ... Fuel tank 3 ... Introductory tube 4 ... Permeation plate 5 ... Permeable membrane 6 ... Receiver 7 ... Liquid storage part 8 ... Core 9 ... Permeable membrane 10 ... Junction 11 ... Single cell 12 ... Gel fuel composition 13: Gel holding material

Claims (5)

[Claims] 1. A fuel composition for a fuel cell, comprising a fuel containing an alcohol having 3 or less carbon atoms and water, and a surfactant. 2. The fuel composition for a fuel cell according to claim 1, further comprising an identification agent. 3. The fuel composition for a fuel cell according to claim 1, further comprising a combustion aid having a lower temperature and a higher vapor pressure than the alcohol. 4. The fuel cell according to claim 1, wherein the content of the alcohol is 30% by weight or less based on the fuel, and the antifreeze agent or the fluidity improver is contained. Fuel composition. 5. A gel fuel composition for a fuel cell, comprising the fuel composition according to any one of claims 1 to 4 and a gelling agent.