JP3511608B1 - Steam electrolyzer - Google Patents

Abstract

Kind Code: A1 The present invention relates to a steam electrolysis apparatus, which does not require a gas-liquid separation tank, a purifying means, or a steam cooling means, and mixes high-purity oxygen and hydrogen from water vapor with liquid water even under zero gravity. To provide a steam electrolyzer that can be taken out without any trouble. A compartment A is provided with a steam generator having a pressure adjusting means, a temperature adjusting means, and a safety valve, and (A) means for introducing steam from the steam generator.
(A) a fluororesin-based ion exchange membrane, (c) a compartment B having hydrogen discharging means and filled with a sponge-shaped cathode,
(D) platinum, iridium, rhodium or iridium-rhodium alloy plated fluororesin-based ion exchange membrane,
(E) An electrolytic cell having an anode formed by plating platinum on porous titanium and (F) sandwiching the compartment C having an oxygen discharging means in the order of (A) to (F).

Description

Detailed Description of the Invention

【Technical field】

The present invention relates to a steam electrolyzer for electrolyzing steam to extract oxygen and hydrogen regardless of the presence or absence of gravity. More specifically, you can supply oxygen onboard the aircraft,
Supplying oxygen and hydrogen as energy sources to fuel cells, supplying oxygen and hydrogen as fuel to maintain life in outer space and spacecraft, or supplying oxygen to jewelery processing oxygen burners In particular, it relates to a steam electrolyzer that can be used.

[Background technology]

2. Description of the Related Art Conventionally, there has been known a water electrolysis device for obtaining oxygen or hydrogen by bringing liquid water or an electrolyte solution into contact with a cathode and an anode to electrolyze it (see, for example, Patent Document 1).

[Patent Document 1] Japanese Patent Laid-Open No. 9-67689 (FIG. 1)

In addition, oxygen and hydrogen are supplied from the loaded water to 8:
A spacecraft provided with an electrolytic cell that is generated at a mass ratio of 1 is known (for example, see Patent Document 2). Further, a closed living space system combined with a fuel cell is known (see, for example, Patent Document 3).

[Patent Document 2] Japanese Patent Laid-Open No. 6-8893 (paragraph 0006)

[Patent Document 3] Japanese Patent Application Laid-Open No. 5-262300 (002)
(0 paragraph)

In view of the above background, the present applicants have developed a water electrolysis device (see, for example, Patent Document 4). Furthermore, an environmental purification type water electrolysis device has been developed (for example, see Patent Document 5).

[Patent Document 4] Japanese Patent Application No. 2003-001862

[Patent Document 5] Japanese Patent Application No. 2003-056632

DISCLOSURE OF THE INVENTION [Problems to be Solved by the Invention]

Conventionally, when electrolyzing steam, a cooling device is required because it is once cooled to form liquid water and then introduced into a water electrolysis device.

Further, when liquid water as an electrolytic solution is brought into contact with the electrodes for electrolysis, bubbles are generated from the respective electrodes to generate oxygen and hydrogen, so that a gas-liquid separation tank for separating gas and liquid is provided. There was a problem that it was necessary. In particular, in the zero-gravity state, there is a problem that gas remains as bubbles in the liquid and cannot be separated.

Further, there is a problem that high-purity water vapor without impurities is required in order to always keep the electric resistance of the ion-exchange membrane as an electrolyte low.

Further, H ⁺ ions generated at the anode move to the cathode together with water, and the water is recovered and returned to the anode.
There was a problem that the water circulation circuit became complicated.

Therefore, in a closed space such as a space environment, even when it is desired to electrolyze and utilize steam contained in air discharged by humans or the like, a purifying means for removing carbon dioxide and methane mixed in, and liquid water cooled. There was a problem that a means to

The present invention has been made in view of the above problems. Therefore, the object of the present invention is to eliminate the need for a gas-liquid separation tank, a purifying means and a steam cooling means, and to obtain high purity from steam even under zero gravity. An object of the present invention is to provide a steam electrolyzer capable of taking out the oxygen and hydrogen of the above-mentioned without being mixed with liquid water. The present inventors have conducted intensive studies to achieve the above object, and as a result, completed the present invention through trial and error.

[Means for Solving the Problems]

In order to achieve the above object, the steam electrolysis apparatus of the present invention has means for introducing steam into the electrolytic cell, and a cathode having steam permeability is provided with a fluororesin ion exchange membrane A and a catalyst. It is sandwiched between fluororesin type ion exchange membranes B, a steam introduction phase is placed outside the ion exchange membrane A, and an anode is placed outside the ion exchange membrane B.
The water vapor introduced into the water vapor introduction phase passes through the ion exchange membrane A and the cathode, is absorbed by the ion exchange membrane B, is electrolyzed by applying a voltage to both electrodes, Protons move from the anode side to the cathode side, hydrogen is generated on the cathode surface, and oxygen is generated on the anode surface, so that the generated oxygen and hydrogen are not mixed with water.

The steam electrolysis apparatus of the present invention is provided with a steam generator having a pressure adjusting means, a temperature adjusting means, and a safety valve, and (a) a compartment A having a means for introducing steam from the steam generator. , (A) Fluororesin-based ion exchange membrane, (c) compartment B having hydrogen discharge means and filled with a sponge-like cathode, (d) platinum, iridium, rhodium or fluorine plated with iridium-rhodium alloy A compartment C having a resin-based ion exchange membrane, (e) an anode formed by plating platinum on porous titanium, and (f) an oxygen exhausting means (a).
From (a) to (f), the electrolytic cell is sandwiched.

【The invention's effect】

The steam electrolyzer of the present invention does not require a gas-liquid separation tank, a purifying means or a steam cooling means, and takes out high-purity oxygen and hydrogen from the steam without mixing with liquid water even under zero gravity. be able to. Further, in a closed space such as a space environment, water vapor contained in air discharged by humans can be easily electrolyzed.

According to the present invention, since oxygen and hydrogen are not generated as bubbles in water, a gas-liquid separation tank is unnecessary.
This has not only the merit in terms of cost but also the merit of being compact and lightweight. Further, according to the present invention, even in the case of electrolyzing water vapor under zero gravity, only the gas can be taken out from the hydrogen outlet and the oxygen outlet, so that there is no fear that water is mixed into the gas at the time of taking out. Compactness is a very important point in spacecraft.

BEST MODE FOR CARRYING OUT THE INVENTION

The feature of the present invention is that it has a means for introducing water vapor into the electrolytic cell, and the water vapor permeable cathode is between the fluororesin ion exchange membrane A and the catalyst-containing fluororesin ion exchange membrane B. The water vapor introduced into the ion exchange membrane A is placed in an electrolytic cell having a water vapor introduction phase outside the ion exchange membrane A and an anode outside the ion exchange membrane B. Water is absorbed by the ion exchange membrane B after passing through the cathode, and electrolyzed by applying a voltage to both electrodes. Protons move in the ion exchange membrane B from the anode side to the cathode side, and hydrogen is deposited on the cathode surface. Is generated, and oxygen is generated on the surface of the anode, so that water is not mixed with the generated oxygen and hydrogen.

Since the inside of the electrolytic cell is at room temperature, water vapor is
In the introduced electrolytic cell, part of the water becomes liquid, but since the water vapor introduction phase and the electrode are separated by the fluororesin ion exchange membrane, the liquid does not come into direct contact with the electrode and the water is ion-exchanged. The film moves from the side having a higher water vapor pressure to the electrode side having a lower water vapor pressure as water vapor for electrolysis.

[Example 1]

FIG. 1 is a block diagram of the first embodiment of the present invention. In Example 1 of the present invention shown in FIG. 1, the steam electrolysis apparatus (1) includes a compartment A (3), an ion exchange membrane A (4), a compartment B (8), an ion exchange which are phases for introducing steam. Membrane B
(5), the anode (9) and the compartment C (11) are sandwiched in this order from the electrolytic cell (12). No gas-liquid separation tank is provided.

The compartment A (3) is provided with a water vapor inlet (2). The compartment B (8) is provided with a hydrogen discharge port (6) and is filled with a sponge-like cathode (7). An oxygen outlet (10) is provided in the compartment C (11). In the compartment C (11), a sponge-like Ni-C is formed in order to improve the contact property between the anode (9) and the ion exchange membrane B (5).
r alloy is filled.

In Example 1 of the present invention shown in FIG. 1, an electrode obtained by plating porous titanium with platinum was used as the anode (9). As the cathode (7), a sponge-like porous electrode of nickel-chromium alloy plated with platinum was used.

In Example 1 of the present invention, as the ion exchange membrane A (4), a fluororesin type ion exchange membrane (for example, NAFION (R) which is a sulfone compound of fluorinated polyolefin manufactured by DuPont) is used. I was there. As the ion exchange membrane B (5), 4 to 5 mg / cm ² of platinum as a catalyst was supported on a fluororesin-based ion exchange membrane. Its effective membrane area is about 200 cm ² . In Example 1 of the present invention, NAFIO was used as the ion exchange membrane of fluororesin.
N (R) 117 (manufactured by DuPont) was used. In addition to platinum, iridium, rhodium, or an iridium-rhodium alloy is suitable as the metal to be plated on the ion exchange membrane.

In the first embodiment of the present invention, the compartment A
The water vapor supplied to (3) is saturated,
Because it does not control the temperature, it becomes liquid water,
It is blocked by the ion exchange membrane A (4). The ion exchange membrane A (4) used in the present invention does not allow liquid to pass therethrough but allows only water to pass through. Therefore, the water formed in the compartment A (3) and the supplied water vapor pass through the ion exchange membrane A (4) as saturated water vapor and further move through the sponge-like cathode (7). That is, the ion exchange membrane A
Utilizing the property that (4) moves only water vapor from the higher vapor pressure side to the lower vapor pressure side, the gaseous H ₂ O is transferred to the ion exchange membrane A.
(4) is supplied to the separated cathode side to cause electrolysis to take out hydrogen and oxygen.

In Example 1 of the present invention, the water vapor introduction phase and the electrode are partitioned by the fluororesin ion exchange membrane, and the liquid does not come into direct contact with the electrode. In Example 1 of the present invention, water migrates through the ion exchange membrane from the side having a higher water vapor pressure to the electrode side having a lower vapor pressure as water vapor, and the water vapor is absorbed by the other ion exchange membrane carrying the catalyst. It is electrolyzed by applying a voltage to the electrodes. Therefore, in the first embodiment of the present invention, liquid water is not mixed with oxygen or hydrogen that is the generated gas.

Further, in Example 1 of the present invention, since water vapor is not supplied from the anode side and the ion exchange membrane does not permeate liquid water, liquid water that moves together with hydrogen ions from the anode is used. Is unnecessary. Further, a device for separating hydrogen / oxygen as a gas and water in a liquid state is not necessary.

Further, in Example 1 of the present invention, since steam can be introduced as it is into the compartment A, which is the steam introduction phase, for electrolysis, no means for cooling the steam is required. Further, even if a gas such as carbon dioxide is mixed in the steam, the steam can be electrolyzed, so that no purification means is required.

The present invention can also be carried out by making the cathode used in Example 1 porous instead of sponge, or using another ion exchange membrane having high water vapor permeability as the ion exchange membrane.

Example 2

FIG. 2 is a block diagram of the second embodiment of the present invention. In Example 2 of the present invention, the steam electrolyzer (1) is further provided with a steam generator (18). Other points are the same as the first embodiment of the present invention.
A water tank (16) having a pressure sensor (19) and a pressure controller (20) as pressure adjusting means, a temperature sensor (23) as temperature adjusting means, and a safety valve (22) in the steam generator (18). Consists of. Further, it has a pressure gauge (21) and a water level gauge (24) for monitoring. The water tank (16) is filled with a certain amount of water, and the water level is adjusted by the control of the water level sensor (25). Water is heater (1
The temperature is adjusted in 3). The heater (13) is connected to the pressure regulator (20) and controls the water vapor pressure to a constant value. The temperature sensor (23) measures the temperature of water vapor. The steam electrolyzer (1) and the steam generator (18) are connected by a steam pipe (17). A heater for preventing dew condensation is wound around the steam pipe (17).

FIG. 3 is a block diagram of the third embodiment of the present invention. In the steam electrolysis apparatus (1) of Example 3 of the present invention, the gas inlet (14) having the check valve (26) and the valve (27) is further provided in Example 2 of the present invention, Any gas can be mixed with steam. Further, a plurality of electrolytic cells (12) are arranged in parallel, and oxygen and hydrogen can be generated with high efficiency.

In the third embodiment of the present invention, a simulated test can be conducted in the case where electrolysis of steam mixed with carbon dioxide, methane and the like is performed in a closed space of the universe.

[Industrial availability]

The steam electrolyzer of the present invention is used to supply oxygen in an aircraft, to supply oxygen / hydrogen as an energy source to a fuel cell, and to maintain life in outer space or spacecraft. Or supply hydrogen as fuel,
Alternatively, it is useful for supplying oxygen to a jewelry processing oxygen burner. Therefore, the use of the steam electrolyzer of the present invention contributes to the progress of space development and the like.

[Brief description of drawings]

[0030]

FIG. 1 is a configuration diagram of a first embodiment of the present invention.

FIG. 2 is a configuration diagram of a second embodiment of the present invention.

FIG. 3 is a configuration diagram of a third embodiment of the present invention.

[Explanation of symbols]

[0031] 1 Steam electrolyzer 2 Steam inlet 3 compartment A 4 Ion exchange membrane A 5 Ion exchange membrane B 6 Hydrogen outlet 7 cathode 8 compartment B 9 Anode 10 oxygen outlet 11 compartment C 12 Electrolyzer 13 heater 14 gas inlet 15 Water outlet 16 water tank 17 Water vapor pipe 18 Steam generator 19 Pressure sensor 20 Pressure regulator 21 pressure gauge 22 Safety valve 23 Temperature sensor 24 Water gauge 25 Water level sensor 26 Check valve 27 valves

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoji Watanabe 5-4-14 Shinjuku, Shinjuku-ku, Tokyo Suga Test Machine Co., Ltd. (56) References: Kaihei 4-21563 (JP, U) Patent 3452140 ( JP, B1) (58) Fields investigated (Int.Cl. ⁷ , DB name) C25B 1/04 C25B 9/00 H01M 8/00

Claims (2)

(57) [Claims] 1. A means for introducing water vapor into an electrolytic cell, wherein a water vapor permeable cathode is sandwiched between a fluororesin-based ion exchange membrane A and a catalyst-containing fluororesin-based ion exchange membrane B, A water vapor introduction phase is arranged outside the ion exchange membrane A,
In an electrolytic cell having an anode arranged outside the ion exchange membrane B, the water vapor introduced into the water vapor introduction phase passes through the ion exchange membrane A and the cathode and is absorbed by the ion exchange membrane B. When a voltage is applied to the electrode, it is electrolyzed, protons move from the anode side to the cathode side in the ion exchange membrane B, hydrogen is generated on the cathode surface, and oxygen is generated on the anode surface. A steam electrolysis device characterized in that hydrogen is not mixed with water. 2. A compartment A provided with a steam generator having a pressure adjusting means, a temperature adjusting means, and a safety valve, and (a) having a means for introducing steam from the steam generator, and (b) a fluororesin. -Based ion exchange membrane, (c) compartment B having hydrogen discharging means and filled with a sponge-like cathode, (d) platinum, iridium, rhodium or iridium-rhodium alloy-plated fluororesin ion exchange membrane, (E) A steam electrolyzing device comprising an electrolytic cell in which an anode made by plating platinum on porous titanium and (f) a compartment C having an oxygen discharging means are sandwiched in the order of (a) to (f).