JPH03177592A - Device for electrochemically transporting oxygen - Google Patents

Abstract

PURPOSE:To selectively transport concd. pure oxygen to oxygen utilizing equipment from an oxygen-contg. gas source by using an electrochemical cell divided into a cathode chamber and an anode chamber by the cation-exchange membrane. CONSTITUTION:The electrochemical cell main body 4 is divided into an anode chamber 8 provided with an anode collector 10 and a cathode chamber 5 furnished with a cathode collector 7 by a cation-exchange membrane 1 with an anode 9 bonded to one side and a cathode 6 to the other side. The main body 4, oxygen-contg. gas source 1 (closed structure) and oxygen utilizing equipment are connected to the second dehumidifier 18, gas-liq. separator 14, first dehumidifier 15 and water tank 17. Consequently, oxygen alone is selectively transported from the source 1, and oxygen having 99.9% purity is transported to the oxygen utilizing equipment.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an apparatus for selectively separating oxygen electrochemically and transporting oxygen. In more detail, we have a device that selectively extracts oxygen generated by plants in a sealed plant cultivation device, a device that selectively extracts oxygen generated by algae in an algae cultivation device, and a device that selectively extracts oxygen generated by algae in an algae cultivation device. Devices for introducing oxygen into underwater structures, devices for selectively transporting oxygen generated by plants or algae in closed structures such as underground cities to spaces inhabited by humans, and space stations or outer space. Advantageously applied to a device that selectively transports oxygen generated by plants or algae in a closed structure in a closed space such as a base to a space where humans live or animals grow. This invention relates to a device that selectively separates oxygen electrochemically and transports oxygen.

[Conventional technology]

Conventionally, a gas containing oxygen is brought into contact with an adsorbent to adsorb oxygen onto the adsorbent, and when the amount of oxygen adsorbed reaches saturation, the adsorbent is heated to desorb the oxygen and selectively collect and transfer oxygen. I was letting it happen.

An example of the prior art will be explained using FIG. 9. For example, a blower 3 sends the gas from a sealed structure 1 containing oxygen-containing gas to an adsorption tower 102 containing an adsorbent 101, so that only oxygen is adsorbed by the adsorbent 101, and the unadsorbed gas is removed by a valve. 103 and back into the closed structure 1.

When the amount of oxygen adsorption reaches saturation, the blower 3 is stopped and the valve 103 is closed.
After closing the valve 104 and opening the valve 105, the adsorption tower 10
2 to about 90° C. to desorb oxygen. The desorbed oxygen is exhausted to the outside through valve 105. When the desorption of oxygen is completed, the adsorption tower 102 is cooled to about 20°C. By repeating the above operations, oxygen was discharged from the sealed structure 1. (Special Publication No. 56-35488) [Problems to be Solved by the Invention] In the conventional technology, the adsorbent deteriorates due to repeated heating and cooling, and harmful gases may be generated. It has been difficult to obtain pure oxygen because it comes out with residual gases. Furthermore, since there is no suitable means for measuring the amount of absorbed M of oxygen, adsorption and desorption are uniquely repeated according to a preset time, making it impossible to respond flexibly to changes in the amount of oxygen to be transported. .

In view of the above state of the art, the present invention aims to provide a device for selectively transporting oxygen from an oxygen generating (or containing) source.

[Means to solve the problem]

The present invention has the following features: (1) An electrochemical cell main body divided into an anode chamber equipped with an anode current collector and a cathode chamber equipped with a cathode current collector by a cation exchange membrane with an anode bonded to one side and a cathode bonded to the other surface. , ■ A water tank communicating with the anode chamber of the cell main body and an oxygen-containing gas generation source communicating with the cathode chamber of the cell main body via a ventilation means; ■ A pump and air source for the oxygen-containing water generated in the anode chamber. Oxygen utilization equipment to which dehydration and dehumidification oxygen is supplied via piping equipped with a liquid separation device and a first dehumidification device, ■ a second dehumidification device that dehumidifies the deoxygenated water-containing gas generated in the anode chamber, ■ the above means for recovering the deoxygenated and dehydrated gas and water separated in the second dehumidifying device, respectively; A device for electrochemically transporting oxygen from an oxygen-containing gas source to an oxygen utilization facility, comprising means for transporting oxygen to a water tank.

As specifically shown in the Examples below, the apparatus for electrochemically transporting oxygen having the above structure of the present invention has various modifications to the above structure depending on the purpose.

[For production]

The electrode reaction of an electrochemical oxygen transport device using a cation exchange membrane as a solid electrolyte, which is a main component of the present invention, is as follows.

Cathode: 02+ 48"+ 4 e--+ 2820
Anode + 2 H2O → 02+ 48" + 4 e Therefore, the gas containing oxygen is supplied to the cathode chamber of the cell body, and at the cathode oxygen reacts with hydrogen ions to produce water. On the other hand,
At the anode, oxygen is produced from the water and is discharged as transported oxygen. H+ generated by the reaction at the anode passes through the cation exchange membrane, and e- moves through the wiring to the cathode where it reacts with oxygen and becomes water.

The iron water is discharged from the cathode chamber of the cell main body together with the oxygen-depleted gas and supplied to the second dehumidifier. The water produced by the reaction at the cathode is removed in the second dehumidifier, and the gas is discharged from the deoxidized gas discharge pipe. The removed water is returned to a water tank that stores water for supply to the anode.

On the other hand, oxygen generated at the anode is discharged from the anode chamber of the cell main body together with water and sent to the gas-liquid separator. In the gas-liquid separator, oxygen is removed as a gas together with water vapor,
Subsequently, after water vapor is removed by the first dehumidifier, it is discharged from the oxygen exhaust pipe. The water separated from oxygen by the gas-liquid separator and the water removed by the first dehumidifier are sent to the water tank, temporarily stored in the water tank, and then supplied to the anode chamber of the cell main body again. .

In this way, oxygen in the gas supplied to the oxygen separation device is converted into water by an electrical reaction at the cathode, and then returned to oxygen at the anode and is discharged.

In the present invention, the specific resistance is 5MΩ・cm (the electrical conductivity is 0.2μ
If water with a temperature of S/cm or higher is used, only the above reaction will proceed and no harmful gas will be generated.

As is clear from the above reaction equation, since the gases discharged from the cell body are only oxygen and water vapor, it is possible to discharge 99.9% or more pure oxygen if water vapor is sufficiently removed. Furthermore, the amount of oxygen transported is completely proportional to the current, and there is a relationship of 210-02/A-hr. Therefore, the amount of oxygen transported can be controlled by changing the current.

Oxygen generated in the anode chamber is sent to the gas-liquid separator along with water. In the gas-liquid separator, gaseous oxygen is separated from water. Iron water is sent to a water tank where water is temporarily stored. Since the oxygen separated from the water contains water vapor at a saturated concentration, in order to obtain more than 99.9% pure oxygen and to minimize water loss, the oxygen is sent to the first dehumidifier. It will be done. The first dehumidifier removes water vapor and exhausts pure oxygen. The water vapor removed in the first dehumidifier becomes a liquid and is sent to the water tank.

Water is generated in the cathode chamber by an electrochemical reaction.

The iron water is sent to the second dehumidifier together with the deoxygenated gas. In the second dehumidifier the water is separated from the deoxygenated gas and sent to the water tank. In this manner, water lost in the anode and cathode chambers in the first and second dehumidifiers is recovered and returned to the water tank, preventing water loss from the electrochemical oxygen transport device. The deoxygenated gas after dehumidification is discharged from the second dehumidifier through the deoxygenated gas exhaust pipe.

[Example 1] Figure 1 shows a sealed structure 1 according to Example 1 of the present invention.
This shows a conceptual diagram of a device that selectively extracts only oxygen from.

The gas in the sealed structure 1 is sent to the cathode chamber 5 of the cell main body 4 through the gas intake pipe 2 by a blower. The cell main body 4 includes a cathode chamber 5 and a cathode 6 that can selectively electrolytically reduce oxygen.
, a cathode current collector 7, an anode chamber 8, an anode 9 serving as an oxygen generating electrode, an anode current collector 10, a cation exchange membrane having the property of physically dividing the cathode chamber 5 and anode chamber 8 and transporting hydrogen ions. 11 and a cell frame 12.

The anode chamber 8 is filled with water.

By passing a direct current between the cathode current collector 7 and the anode current collector 10, water is electrolyzed at the anode 9 to generate oxygen and hydrogen ions.

The hydrogen ions move to the cathode chamber 5 through the cation exchange membrane 11, undergo an electrolytic reduction reaction with oxygen contained in the gas sent to the cathode chamber 5 at the cathode 6, and produce water.

Oxygen generated at the anode 9 is sent together with water filling the anode chamber 8 to a gas-liquid separator 14 by a pump 13. In the gas-liquid separator 14, gaseous oxygen is separated from water. The oxygen contains water vapor at a saturated concentration and is sent to the first dehumidifier 15. Water vapor is completely removed in the first dehumidifier 15 and pure oxygen is discharged from the oxygen discharge pipe 16. The water vapor removed in the first dehumidifier 15 becomes a liquid and is sent to the water tank 17 together with water separated from oxygen in the gas-liquid separator 14. After being temporarily stored in the water tank 17, the water is pushed out and sent to the anode chamber 8 of the cell body 84 again.

On the other hand, the gas sent to the cathode chamber 5 is sent to the second dehumidifier 18 together with water generated by an electrolytic reduction reaction at the cathode 5. Water is removed in the second dehumidifier 18 and the deoxygenated gas is discharged from the deoxidized gas discharge pipe 19 to the sealed structure 1.
will be returned to. The water produced by the reaction in the second dehumidifier 18 is recovered, and this water is also sent to the water tank 17.

If there is an oxygen generation source in a sealed structure 1 and oxygen concentration control is required, an oxygen concentration sensor 20 is attached to the sealed structure 1, and a current control device 21 is used to connect the cathode current collector 7 and the anode. The amount of oxygen transported is controlled by adjusting the current between the current collector 10 and the oxygen concentration within the sealed structure 1.

The electrode reaction in the cell main body 4 is at a current density of 50 mA/cm"
The above is stable. Circulating water temperature 40℃, atmospheric temperature 4-6
i! /min, when using a platinum electrode with an effective electrode area of 100 cm' as the anode 9, the current density is 50 to 200 mA/cm2 and the voltage is 1.2
~1.5V (Figure 2 A) Oxygen transport amount is 1.05~4.2
110. / hr, and the effective electrode area 1 as anode 9
When using an iridium electrode of 00 cm', the current density is 50 to 300 mΔ/cm' and the voltage is 0.75 to 1,
2V (Figure 2B) oxygen transport amount is 1.05 to 13,31[
l□/hr. For example, the standard oxygen transport amount is 3
In the case of fO□/hr, the effective electrode area is 100 as the anode 9.
35 to 210% when using an iridium electrode of Cm"
Since the amount of oxygen transport can be adjusted within the range of . If oxygen transport is less than 35% of capacity,
The adjustment may be made by opening and closing a switch 22 between the cathode current collector 7 and the anode current collector 10.

[Embodiment 2] FIG. 3 shows a conceptual diagram of a mechanism for selectively sending only oxygen into the outlet-side sealed structure 23 according to Embodiment 2 of the present invention.

The difference from Embodiment 1 shown in FIG. The only difference is that a structure is attached and only oxygen is selectively sent into the structure 23 sealed on the outlet side, and the other configurations are the same as in Example 1.

There is an oxygen consumption source in the outlet-side sealed structure 23;
In addition, if oxygen concentration control is required, an oxygen concentration sensor 20 is attached to the closed structure 23 on the outlet side, and the current between the cathode current collector 7 and the anode current collector 10 is regulated by the current control device 21. to control the amount of oxygen transported and the oxygen concentration within the closed structure 23 on the outlet side. Since the oxygen transport amount can be adjusted in the range of 35 to 210%, this is especially useful when there is an oxygen consuming source whose oxygen consumption rate fluctuates, such as when humans live or animals are kept in the closed structure 23 on the exit side. The device of this second embodiment is effective.

[Embodiment 3] FIG. 4 shows a conceptual diagram of a mechanism for selectively sending only oxygen from the sealed structure 1 to the outlet-side sealed structure 23 according to Embodiment 3 of the present invention.

The difference between Embodiment 1 shown in FIG. 3 and Embodiment 2 shown in FIG. For,
In the third embodiment, a sealed structure is attached to both the gas intake pipe 2 and the oxygen discharge pipe 16, and only oxygen is selectively transported from the sealed structure 1 to the outlet-side sealed structure 23. The other configuration is the same as in Example 1.2.

If there is an oxygen generation source in the sealed structure 1 or an oxygen consumption source in the outlet-side sealed structure 23 and oxygen concentration control is required, the sealed structure 1 Alternatively, the oxygen concentration sensor 20 is attached to the closed structure 23 on the outlet side, and the current between the cathode current collector 7 and the anode current collector 10 is adjusted by the current control device 21 to control the amount of oxygen transported, and the structure is sealed. inside the structure l or on the exit side sealed structure 2
Control the oxygen concentration within 3. Since the oxygen transport amount can be adjusted in the range of 35 to 210%, it can be used when there is an oxygen generating source whose oxygen generation rate fluctuates, such as plant cultivation or algae cultivation, in a closed structure, or when the outlet side is sealed. The device of the third embodiment is particularly effective when there is an oxygen consumption source whose oxygen consumption rate fluctuates, such as when humans live or animals are kept in the structure 23.

[Example 4] Figure 5 shows a sealed structure l according to Example 4 of the present invention.
FIG. 2 is a conceptual diagram of a case where only oxygen is selectively sent from the outlet side to the closed structure 23 and oxygen concentration is controlled in both the closed structure 1 and the outlet side sealed structure 23.

The only difference from the third embodiment shown in FIG. 4 is that it includes an oxygen tank 24, and the other configurations are the same as the third embodiment.

Oxygen transported from the sealed structure 1 via the cell body 4 is temporarily put into an oxygen tank 24 provided in the oxygen exhaust pipe 16. When the oxygen concentration in the outlet-side sealed structure 23 falls below a predetermined value, the valve 25 of the oxygen tank 24 is opened to send oxygen into the outlet-side sealed structure 23 to adjust the oxygen concentration. Since pure oxygen can be obtained in the apparatus of this fourth embodiment, the oxygen tank 24 can be made smaller.

[Example 5] Figure 6 shows a sealed structure 1 according to Example 5 of the present invention.
It is a conceptual diagram when only oxygen is selectively sent from the outlet side to the closed structure 23, and the oxygen concentration is controlled in both the closed structure 1 and the outlet side closed structure 23, Its operation is the same as in Example 4.

The difference from Embodiment 4 is that normally the valve 26 provided in the oxygen discharge pipe 16 is open and the oxygen transported from the sealed structure 1 via the cell body 4 is directly discharged from the closed structure. The structure 23 is fed into the structure 23 and the exit side is sealed.
When the oxygen concentration becomes higher than a predetermined value, the valve 26 is closed, and the valve 27 provided on the bypass pipe of the oxygen discharge pipe 16 is opened to temporarily store oxygen in the oxygen tank 24 provided on the bypass pipe, and the outlet side is sealed. When the oxygen concentration in the closed structure 23 becomes lower than a predetermined value, the valve 25 of the oxygen tank 24 is opened and pure oxygen is sent through the bypass pipe to adjust the oxygen concentration in the closed structure 23 on the outlet side. This is the only difference, and the other configurations are the same as in the fourth embodiment.

Since pure oxygen can be obtained in the apparatus of this fifth embodiment, the oxygen tank 24 can be made even smaller.

[Example 6. ] No. 7 rgJ is the device according to Example 6 of the present invention,
A conceptual diagram of a device that selectively extracts only oxygen from oxygen-containing water is shown.

35 indicates a partition that separates the water from the space in which the oxygen transport device is installed. Water is sent from the submersible 28 to the gas permeation part 30 by the pump 29, while gas is sent from the gas tank 31 to the gas permeation part 30 by the blower 3, and the oxygen contained in the water is transferred to gas in the gas permeation part 30. The increased gas is sent to the cell main body 4, and the structure after the cell main body 4 is the same as that of the first embodiment shown in FIG.

The gas sent to the cell main body 4 becomes a deoxygenated gas and returns to the gas tank 31 through the deoxygenated gas exhaust pipe 19. The water deoxidized in the gas permeation section 30 is discharged into the water 28 through the deoxygenated water discharge pipe 36. If there is an oxygen generation source in underwater 28 and oxygen concentration control is required, use underwater 28
An oxygen concentration sensor 20 is attached to the tank, and a current control device 21 adjusts the current between the cathode current collector 7 and the anode current collector 10 to control the amount of oxygen transported and the oxygen concentration of the water 28. Since the oxygen transport amount can be adjusted in the range of 35 to 210%, the device of Example 6 is particularly effective when there is an oxygen 5 generation source whose oxygen generation rate fluctuates, such as when algae are cultivated underwater. .

Although nothing is attached to the oxygen exhaust pipe 16 in FIG. 7, if the oxygen concentration of the outlet-side sealed structure 23 is adjusted by attaching the outlet-side sealed structure 23 to the oxygen exhaust pipe 16, the third The configurations described in Embodiment 2 in the figure, Embodiment 3 in FIG. 4, Embodiment 4 in FIG. 5, and Embodiment 5 in FIG. 6 may be combined.

[Embodiment 7] FIG. 8 shows a conceptual diagram of an apparatus for selectively dissolving only oxygen into water according to Embodiment 7 of the present invention.

Reference numeral 37 indicates a partition that separates the outlet side water from the space in which the oxygen transport mechanism is installed. The configuration up to the oxygen exhaust pipe 16 is the third
This is the same as the second embodiment shown in the figure.

The oxygen that comes out of the oxygen exhaust pipe 16 is temporarily transferred to the oxygen tank 24.
The blower 38 sends oxygen from the oxygen tank 24 to the outlet side gas permeation part 32, while water is sent from the outlet side submersible 33 to the outlet side gas permeation part 32 by the outlet side pump 34, and in the outlet side gas permeation part 32. Oxygen is dissolved in the water, and water with increased dissolved oxygen is discharged to the outlet side water 33 through an oxygen-enriched water discharge pipe 39. Since the oxygen coming out of the outlet side gas permeation section 32 has increased humidity, it is returned to the oxygen tank 24 after being dehumidified by the first dehumidifier 15. If there is an oxygen consumption source in the outlet side underwater 33 and oxygen concentration control is required, an oxygen concentration sensor 20 is attached to the outlet side underwater 33, and the current control device 21 controls the cathode current collector 7 and the anode current collector 10. The amount of oxygen transported is controlled by adjusting the current between them, and the oxygen concentration in the water 33 on the outlet side is controlled. Since the oxygen transport amount can be adjusted in the range of 35 to 210%, this embodiment 7 is particularly useful when there is an oxygen consumption source whose oxygen consumption rate fluctuates, such as when fish breeding is carried out in the closed structure 23 on the exit side. device is effective.

Although nothing is attached to the gas intake pipe 2 in Fig. 8, if the sealed structure 1 is attached to the gas intake pipe 2 to adjust the oxygen concentration in the sealed structure 1, the The configurations described in Example 3, Example 4 in FIG. 5, and Example 5 in FIG. 6 may be combined. Also, the gas intake pipe 2 is underwater 28
If the structure is to be connected to the fourth embodiment shown in FIG. 5, the fifth embodiment shown in FIG. 6, and the sixth embodiment shown in FIG.

〔Effect of the invention〕

According to the present invention, only oxygen is selectively transported and the concentration of oxygen is 9.
It became possible to obtain pure oxygen of 9.9% or more.

In the obtained oxygen gas, the only component other than oxygen is water, so no harmful gas is generated, and it is safe to use when there are living organisms at the destination where oxygen is transported. In addition, by changing the current, the standard transport capacity of 35~
The amount of oxygen transported can be freely varied within a range of 210%. Even when the oxygen transport amount is less than 35%, control is possible by opening and closing the current switch 22. Therefore, it has become easy to transport oxygen while controlling the oxygen concentration in the sealed structure and the dissolved oxygen concentration in water.

[Brief explanation of drawings]

FIG. 1 is a conceptual diagram showing a device for selectively extracting only oxygen from a sealed structure according to Embodiment 1 of the present invention;
The figure is a chart showing the relationship between current density and voltage when platinum electrodes and iridium electrodes are used as anodes, and Figure 3 is a graph showing the relationship between current density and voltage when platinum electrodes and iridium electrodes are used as anodes. FIG. 4 is a conceptual diagram showing a device for selectively sending only oxygen from a sealed structure to a sealed structure on the outlet side according to Embodiment 3 of the present invention; FIG. Embodiment 4 of the present invention selectively sends only oxygen from the sealed structure to the outlet-side sealed structure, and both the sealed structure and the outlet-side sealed structure FIG. 6 is a conceptual diagram showing a device for controlling oxygen concentration, which selectively sends only oxygen/element from a sealed structure to a sealed structure on the outlet side according to Embodiment 5 of the present invention. FIG. 7 is a conceptual diagram showing a device for controlling oxygen concentration in both a closed structure and a closed structure on the outlet side. A conceptual diagram showing a device for taking out;
FIG. 8 is a conceptual diagram showing a device for selectively dissolving only oxygen into water according to Example 7 of the present invention, and FIG. 9 shows a device for selectively transporting only oxygen using a conventional adsorbent. It is a conceptual diagram.

Claims (7)

[Claims] (1) [1] An electrochemical cell body divided into an anode chamber with an anode current collector and a cathode chamber with a cathode current collector by a cation exchange membrane with an anode on one side and a cathode on the other side. [2] A water tank communicating with the anode chamber of the cell main body and an oxygen-containing gas generation source communicating with the cathode chamber of the cell main body via a blowing means; [3] Oxygen-containing gas generated in the anode chamber. Water is dehydrated through piping equipped with a pump, a gas-liquid separator, and a first dehumidifier,
Oxygen utilization equipment supplied with dehumidified oxygen; [4] A second dehumidifier that dehumidifies the deoxygenated and moisture-containing gas generated in the cathode chamber; [5] Deoxygenated and dehydrated gas separated by the second dehumidifier. and means for recovering water, respectively; [6] means for transferring the water separated by the gas-liquid separator and the first dehumidifying device and the water separated by the second dehumidifying device to the water tank. A device that electrochemically transports oxygen from an oxygen-containing gas source to oxygen utilization equipment. (2) The device according to claim (1), wherein the oxygen-containing gas generation source and/or the oxygen utilization equipment are sealed structures. (3) Claim (1) or (2) wherein an oxygen sensor is provided in the oxygen-containing gas generation source and/or the oxygen utilization equipment, and the electrode reaction in the cell main body is controlled by the oxygen concentration signal from the oxygen sensor.
) device described. (4) In an oxygen-containing gas source that is a sealed structure,
The apparatus according to claim 2 or 3, wherein the deoxygenated and dehydrated gas is returned. (5) The apparatus according to any one of claims (1) to (4), further comprising an oxygen storage tank provided in a supply path for dehydrating and dehumidifying oxygen to the oxygen utilization equipment. (6) The device according to any one of claims (1) to (5), wherein the oxygen-containing gas generation source is an oxygen-enriched gas obtained by contacting oxygen-containing water with a gas with a low oxygen concentration. . (7) The device according to any one of claims (1) to (6), wherein the oxygen utilization equipment is water.