JPH11339826A - Method for producing alcohol and phosphoric acid mixture and apparatus therefor - Google Patents

Abstract

(57) [Summary] An electrolyte matrix provided in a phosphoric acid type fuel cell can be impregnated with a predetermined amount of phosphoric acid, and there is little possibility of corroding metal containers and metal pipes as peripheral members. To provide a method for producing an alcohol-phosphoric acid mixed solution and an apparatus therefor. A method for producing a mixed solution of alcohol and phosphoric acid for impregnating phosphoric acid into an electrolyte matrix provided in a phosphoric acid type fuel cell, wherein the alcohol and phosphoric acid are stirred and mixed while being cooled, A method for producing a mixed solution of alcohol and phosphoric acid, characterized in that both are brought into a uniform mixed state at normal temperature, a container 1 containing alcohol and phosphoric acid and placed in a cooling atmosphere, and stirring the alcohol and phosphoric acid. A mixing device 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing an alcohol / phosphoric acid mixture for impregnating an electrolyte matrix of a phosphoric acid fuel cell and an apparatus therefor.

[0002]

2. Description of the Related Art Japanese Unexamined Patent Publication No. Hei 3-254067 discloses a fuel cell electrode catalyst layer in which an electrode of a phosphoric acid fuel cell is impregnated with alcohol, the alcohol is replaced with a phosphoric acid solution, and then the alcohol is removed. Is disclosed.

Next, the operation of this conventional example will be described.
FIG. 5 is a diagram for explaining a phosphoric acid impregnation step of a conventional example. In step 1 (S1), the electrolyte matrix of the fuel cell is immersed in the alcohol for several minutes to impregnate the electrolyte matrix with the alcohol. Next, in Step 2 (S2), the electrolyte matrix impregnated with alcohol is immersed in a phosphoric acid aqueous solution, and the alcohol is substantially replaced with phosphoric acid. Finally, in step 3 (S3), the alcohol remaining in the electrolyte matrix replaced with phosphoric acid is removed by vacuum drying or the like. Originally, phosphoric acid, which is used as an electrolyte of a fuel cell, is difficult to impregnate at room temperature. Impregnation becomes easy.

[0004]

However, in the conventional method for manufacturing an electrolyte for a fuel cell, the electrolyte matrix is separately immersed in alcohol and phosphoric acid. It is difficult to control how much the acid is impregnated (impregnation amount). This is because there is a possibility that a large amount of errors between individual electrolyte matrices and errors during immersion and removal are included. In the impregnation of phosphoric acid using alcohol, the phosphoric acid is easily wetted by the catalyst in the electrolyte matrix, and a fuel gas (or an oxidizing gas) serving as an electromotive force of the fuel cell.
Easily diffuses into the catalyst in the electrolyte matrix. Therefore, accurately controlling the phosphoric acid impregnation amount during fuel cell assembly is a very important point in extending the life of the fuel cell.

Therefore, a method is employed in which alcohol and phosphoric acid are preliminarily mixed and used as an electrolyte for a fuel cell, and this solution is impregnated in an electrolyte matrix. At this time, in order to impregnate the electrolyte matrix with an appropriate amount of phosphoric acid, the alcohol and phosphoric acid mixture to be impregnated should be manufactured at a uniform predetermined concentration. However, alcohol and phosphoric acid have different specific gravities, and thus are difficult to completely dissolve. Also, in order to make alcohol and phosphoric acid uniform, it is necessary to stir and mix for several minutes, but if mixing and stirring is continued for a long time, the temperature rises to about 80 ° C., and metal containers and metal pipes as peripheral members are removed. There is a problem of corrosion. Therefore, conventionally, in order to avoid corrosion of the metal member, it was impossible to stir and mix alcohol and phosphoric acid until they were made uniform, and it was not possible to accurately control the amount of phosphoric acid in the electrolyte matrix.

The present invention solves the above-mentioned conventional problems and can impregnate a predetermined amount of phosphoric acid into an electrolyte matrix provided in a phosphoric acid type fuel cell. Less likely to corrode,
An object of the present invention is to provide a method for producing a mixed solution of alcohol and phosphoric acid and an apparatus therefor.

[0007]

The invention according to claim 1 is a method for producing a mixed solution of alcohol and phosphoric acid for impregnating phosphoric acid into an electrolyte matrix provided in a phosphoric acid type fuel cell, A method for producing a mixed solution of alcohol and phosphoric acid, which comprises stirring and mixing phosphoric acid and phosphoric acid while cooling them to form a uniform mixed state at room temperature. The invention according to claim 2 is a method for producing a mixed solution of alcohol and phosphoric acid for impregnating phosphoric acid into an electrolyte matrix provided in a phosphoric acid fuel cell,
Storing the alcohol and phosphoric acid at a low temperature, stirring and mixing the two, if desired, until the mixture becomes uniform, and heating the mixture to room temperature by the heat generation of the obtained mixture; This is a method for producing a mixed solution. The invention according to claim 3 is an apparatus for producing a mixture of alcohol and phosphoric acid for impregnating an electrolyte matrix provided with phosphoric acid with phosphoric acid, wherein the alcohol and phosphoric acid are contained and cooled in a cooling atmosphere. A production apparatus comprising: a container to be filled; and means for stirring and mixing the alcohol and phosphoric acid. A fourth aspect of the present invention is the manufacturing apparatus according to the third aspect, wherein the cooling means is detachably provided around the container. The invention according to claim 5 is an apparatus for producing a mixed solution of alcohol and phosphoric acid for impregnating phosphoric acid into an electrolyte matrix provided in a phosphoric acid type fuel cell. Container to be placed, means for rotating the container, means for turning the opening of the container downward, and surrounding the container, wherein the opening is directed downward and the alcohol and phosphoric acid mixture liquid flows from the opening. A manufacturing apparatus comprising: a tank for storing the mixed liquid when discharged; and a mixed liquid outlet provided at a bottom of the tank.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 FIG. 1 shows the first embodiment. FIG. In FIG. 1, 1 is a resin container, 2 is an openable / closable lid, 3 is a stirring propeller, and 5 is a mixed liquid outlet. Alcohol and phosphoric acid are accommodated in the container 1 by first removing the openable / closable lid 2. Next, the alcohol and the phosphoric acid are stirred and mixed while cooling the container 1. Embodiment 1 In this case, the container 1 is a closed double container, and liquid nitrogen can be introduced around the container 1. The stirring and mixing of the alcohol and the phosphoric acid are performed by a stirring propeller 3 provided at the bottom of the container 1.
Done by At the bottom of the container 1, there is provided a mixed liquid take-out port 5 for taking out a prepared mixed liquid of alcohol and phosphoric acid. When alcohol and phosphoric acid are stirred and mixed, heat is generated, but cooled by liquid nitrogen around the container, and the alcohol and phosphoric acid mixture is
It is stirred uniformly while always being kept at room temperature. The prepared alcohol and phosphoric acid mixture is subsequently impregnated into the electrolyte matrix 7 by the mixture applicator 6.

Embodiment 2 Embodiment 1 above. In the above, the container 1 containing alcohol and phosphoric acid was cooled in a low-temperature room without forming the container 1 into a closed double container, made into a sherbet shape, and, when desired, both were stirred and mixed until uniform.
The mixture may be heated to room temperature by the heat generation of the obtained mixture, and the alcohol and phosphoric acid may be uniformly stirred and mixed. Here, the low temperature is, for example, about −5 to 5 ° C., and usually around 0 ° C. FIG. FIG. FIG. 2 is substantially the same as FIG. 1 described above, but since the container 1 is placed in a low-temperature room, it is not a closed double container, and there is no need to introduce liquid nitrogen around the container 1.

Embodiment 3 FIG.
It is a figure for explaining. In the circumference of container 1, the means for cooling this is provided detachably. The cooling means is an insulated double-structured outer container containing liquid nitrogen. The stirring means is the stirring propeller 3, and its rotating shaft 8
Is connected to a motor 9 on the upper side through the opening / closing lid 2. The penetrating portion of the rotating shaft with respect to the openable / closable lid 2 is sealed so that evaporation of the mixed solution is suppressed and the absolute amount of the whole liquid does not change. The prepared mixed liquid is taken out by removing the container 1 from the cooling means, and further removing the opening / closing lid 2. When alcohol and phosphoric acid are stirred and mixed, heat is generated. However, the mixture is cooled by liquid nitrogen around the container, and the alcohol and phosphoric acid mixture is constantly stirred while being kept at room temperature.

Embodiment 4 FIG.
FIG. In FIG. 4, a container 1 containing alcohol and phosphoric acid and placed in a cooling atmosphere
Is connected to a motor 9 for rotating the container 1 by a rotating shaft 8, and the shaft is inclined in the horizontal direction. A gear 10 is provided around the container 1 in a vertical direction, and the gear 10 is rotated by appropriate means so that the opening of the container 1 faces downward. Further, a tank 11 is provided so as to surround the container 1, and when the mixture of the alcohol and the phosphoric acid is discharged with the opening of the container 1 facing downward (the mixture of the alcohol and the phosphoric acid is discharged). At the time of taking out, the opening / closing lid 2 is removed). In addition, a mixed liquid outlet 12 is provided at the bottom of the tank 11. If you do this,
It is easy to take out the prepared alcohol and phosphoric acid mixture. The alcohol and phosphoric acid mixture prepared and taken out is subsequently used in Embodiment 1. Similarly, the electrolyte matrix 7 is impregnated with the mixture applicator 6.

The method and apparatus of the present invention can be applied, for example, to manufacture a fuel cell having a conventional fuel electrode, an electrolyte matrix, an oxidant electrode, a porous carbon plate, and a gas separation plate. The alcohol used in the present invention is not particularly limited in its kind, and examples thereof include C1 to C10 alcohols and derivatives thereof. The alcohol to which the present invention can be suitably applied and which is commercially available include ethyl alcohol and dibutyl alcohol phthalate. Further, the mixing ratio of the alcohol and the phosphoric acid is not particularly limited, but is, for example, about 20 to 40% by weight of the alcohol and about 60 to 80% by weight of the phosphoric acid.

[0013]

According to the first aspect of the present invention, since the alcohol and the phosphoric acid are stirred and mixed while being cooled, the alcohol and the phosphoric acid are uniformly mixed at room temperature, whereby a predetermined amount of the phosphoric acid is added to the electrolyte matrix. It can be impregnated, allowing precise control of the amount of phosphoric acid in the electrolyte matrix. As a result, the catalyst of the fuel cell is prevented from being excessively wetted by phosphoric acid, and the diffusion of the fuel gas (oxidizing gas) in the electrolyte matrix is not hindered, thereby extending the life of the fuel cell. . In addition, since a mixed solution of alcohol and phosphoric acid at room temperature is used, corrosion of peripheral members made of metal or the like can be prevented.

According to the second aspect of the present invention, the alcohol and the phosphoric acid are stored at a low temperature, and when desired, the two are stirred and mixed until uniform, and the mixture is heated to room temperature by the heat generated from the obtained mixture. It is characterized by being heated, so that both are in a uniform mixed state at room temperature, whereby a predetermined amount of phosphoric acid can be impregnated into the electrolyte matrix, and the amount of phosphoric acid in the electrolyte matrix can be accurately controlled. Becomes possible. As a result, the catalyst of the fuel cell is prevented from being excessively wetted by phosphoric acid, and the diffusion of the fuel gas (oxidizing gas) in the electrolyte matrix is not hindered, thereby extending the life of the fuel cell. . In addition, since a mixed solution of alcohol and phosphoric acid at room temperature is used, corrosion of peripheral members made of metal or the like can be prevented. In addition, the storage of alcohol and phosphoric acid at low temperatures has the advantage of being relatively inexpensive.

According to the third aspect of the present invention, since there are provided a container for accommodating alcohol and phosphoric acid and placed in a cooling atmosphere, and a means for stirring and mixing the alcohol and phosphoric acid, both of them are kept at room temperature. Is in a homogeneous mixed state, whereby a predetermined amount of phosphoric acid can be impregnated into the electrolyte matrix.

According to the fourth aspect of the present invention, since the cooling means is detachably provided around the container, ready-made products can be used, and the apparatus can be manufactured relatively simply.

According to the invention of claim 5, a container containing alcohol and phosphoric acid and placed in a cooling atmosphere, means for rotating the container, means for turning the opening of the container downward, A tank containing the mixed liquid when the alcohol and the phosphoric acid mixed liquid are discharged from the opening with the opening facing down while surrounding the container, and a mixed liquid take-out provided at the bottom of the tank. And a mouth, so that both are in a uniform mixed state at normal temperature, whereby a predetermined amount of phosphoric acid can be impregnated into the electrolyte matrix, and at the same time, the prepared alcohol and phosphoric acid mixed solution is taken out. Becomes easier.

[Brief description of the drawings]

FIG. 1 shows a first embodiment of the present invention. FIG.

FIG. 2 shows a second embodiment of the present invention. FIG.

FIG. 3 shows a third embodiment of the present invention. FIG.

FIG. 4 shows a fourth embodiment of the present invention. FIG.

FIG. 5 is a diagram for explaining a conventional example.

[Explanation of symbols]

1 container, 2 lid for opening and closing, 3 stirring propeller, 5
Mixture outlet, 6 solution applicator, 7 electrolyte matrix, 8 rotating shaft, 9 motor, 10 gears, 11
Vessel, 12 mixture outlet

Claims (5)

[Claims] 1. A method for producing a mixed solution of alcohol and phosphoric acid for impregnating an electrolyte matrix provided in a phosphoric acid type fuel cell with phosphoric acid, wherein said alcohol and phosphoric acid are stirred and mixed while being cooled. A method for producing a mixed solution of alcohol and phosphoric acid, wherein the two are brought into a uniform mixed state at normal temperature. 2. A method for producing a mixed solution of alcohol and phosphoric acid for impregnating an electrolyte matrix provided in a phosphoric acid fuel cell with phosphoric acid, wherein the alcohol and phosphoric acid are stored at a low temperature, A method for producing a mixed solution of alcohol and phosphoric acid, wherein, when desired, the two are stirred and mixed until uniform, and the mixture is heated to room temperature by heat generation of the obtained mixture. 3. An apparatus for producing a mixed solution of alcohol and phosphoric acid for impregnating an electrolyte matrix with phosphoric acid provided in a phosphoric acid fuel cell, wherein the container contains alcohol and phosphoric acid and is placed under a cooling atmosphere. And a means for stirring and mixing the alcohol and phosphoric acid. 4. The manufacturing apparatus according to claim 3, wherein a cooling means is detachably provided around the container. 5. An apparatus for producing a mixed solution of alcohol and phosphoric acid for impregnating an electrolyte matrix with phosphoric acid provided in a phosphoric acid type fuel cell, wherein the container contains alcohol and phosphoric acid and is placed under a cooling atmosphere. Means for rotating the container; means for turning the opening of the container downward; and surrounding the container, the opening facing downward and the alcohol and phosphoric acid mixture is discharged from the opening. And a mixed liquid outlet provided at the bottom of the tank.