JPS5831089A - Unipolar electrolytic cell - Google Patents

Abstract

PURPOSE:To provide a unipolar electrolytic cell which performs electrolysis on low electrolytic voltage with good electric current efficiency by laminating a gasket contg. a porous anode, a fluorine-contg. cation exchange membrane and a gasket contg. a porous cathode successively. CONSTITUTION:In an electrolytic cell suited particularly for electrolysis of an aq. alkali metallic salt, electric feeding bodies produced by forming porous electrodes 2 and gaskets 1 to one body, providing communicating ports 3 and communicating grooves 4 to the top and bottom and mounting a bus bar 5 are mounted on the right and left. The electrolytic cell is preferably longer in the height direction than in the width direction, and the thicknesses of the gaskets are made generally the same as the thickness of the electrode or thinner by <20%, more preferably 5% than the thickness of the electrodes. The velocity of flow of circulating liquid is extremely important; the liquid is generally used in an about 1-300cm/sec rate. Thus in the case of electrolyzing an alkali metallic salt, the current density up to about 5-200A/dm<2> is possible.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electrolytic cell with a novel structure using an ion-exchange membrane, particularly a monopolar electrolytic cell using an ion-exchange membrane as a diaphragm, which is suitable for efficiently electrolyzing an alkali metal salt aqueous solution at an electrolytic voltage. Regarding electrolytic cells.

In recent years, so-called ion-exchange membrane electrolysis using an ion-exchange membrane as a diaphragm has attracted attention as an energy-saving process because of its low energy consumption. In the field of salt electrolysis for producing sodium chloride, chlorine, and hydrogen, active research and development is underway on ion-exchange membrane electrolysis technology that consumes less energy.

The inventors of the present invention have conducted extensive research in order to reduce the power consumption rate from the viewpoint of energy saving regarding the ion exchange farming electrolysis of the aqueous solution of fulkali metal salts as described above. This has led to the invention. That is, in order to lower the electrolytic voltage in the electrolysis of aqueous alkali metal salt solutions, K is used to reduce the electrolytic voltage by the theoretical decomposition voltage, the electrode overvoltage, the voltage drop due to the electrical resistance of the membrane, the solution resistance, the bubble resistance, and the concentration polarization directly at the electrode field. ,
It is required to suppress the concentration potential and membrane potential based on concentration polarization at the layer interface. The present invention is an electrolytic cell suitable for easily achieving such requirements.

According to the present invention, a monopolar electrolytic cell is provided in which a structural unit is repeated in which a gasket containing a porous anode, a fluorine-containing cation exchange membrane, and a gasket containing a porous cathode are sequentially laminated. That is, in the present invention, a porous anode built into a gasket, a fluorine-containing cation exchange membrane, and a porous cathode are stacked, and an anode chamber and a cathode chamber divided by the cation exchange membrane are repeatedly configured. It is a monopolar electrolytic cell.

In the electrolytic cell of the present invention, the anode chamber and the cathode chamber are provided with a communication port and a communication groove for supplying and discharging a predetermined solution, respectively. That is, the inlet and outlet of each solution communicate with each other, and are connected to the communication grooves serving as the solution inlet passage and the solution outlet passage of the anode chamber and the cathode chamber, respectively. Therefore, the gasket incorporating a porous anode or a porous cathode of the present invention has a porous anode (2) or a porous cathode (2) on the inner circumference of the gasket (1), as illustrated in FIG. ) with built-in gaskets) (
1) has one or more communication ports (3) and communication grooves (4) for supplying and discharging solutions.

The shape of the anode and cathode used in the present invention may be any porous material that is permeable to liquids and gases, such as lath material, spaghetti-like mesh, expanded mesh, metal cloth, and spongy material, so that the surface area is as large as possible. It is preferable to have a uniform porous flat plate shape and a certain degree of flexible surface properties suitable for disturbing the flow lines of the solution and quickly releasing the gas generated at the nuclear electrode. The materials for the anode include those conventionally used as anodes, such as ferrite, noble metals such as platinum, platinum coated on a titanium substrate, niobium, ruthenium oxide on titanium, I
These include those coated with titanium chloride, or those coated with one or more other compounds such as rhodium, palladium v-osmium, iridium, and platinum. In addition, the cathode materials include soft iron, nickel, and the same noble metals used for the anode, such as platinum, I:Idium, palladium, and ruthenium! It is desirable that materials such as iridium, male Zium, and carbon do not change over time in a reducing atmosphere, are not ablated by the cathode 1iK, and have a cathode overvoltage as low as possible. For example, in the case of alkali metal salt aqueous solution electrolysis, cathode overvoltage is preferably 1001 LV or less and somv or less.

The thickness of the electrode is not particularly limited, but may be 103 or less, or even 1 or less, and is generally from 0.05 to 10 fi, although it is highly desirable from an economical point of view. Note that a lip or wire-like power supply body or reinforcing material may be welded to the electrode for power supply. The material needs to have corrosion resistance and high electrical conductivity, but it may be coated with a fluorine-containing polymer such as polytetrafluoroethylene, FgP, PFA, etc. to impart corrosion resistance.

Gasket materials include titanium plates, clad plates made of soft iron with titanium thin plates bonded to them, and various oxidation-resistant and heat-resistant polymers such as polytetrafluoroethylene, FEP, and P.
A copolymer of FA tethylene and tetrafluoroethylene is preferably used. Also, regular rubber.

When using a graded hydrogen polymer such as polyolefin or poly/%R vinylide, the surface layer portion, the portion of lI# that comes into contact with the polar liquid, may be coated with a corrosion-resistant material. Alternatively, only the surface layer may be subjected to a treatment such as fluorination. What gaskets have in common is that they must have a certain degree of elasticity, so if metal is used, it is best to use a tight one or both materials such as polytetrafluoroethylene. The thickness of the gasket is general KO,
02 to 20 curse words are preferably used, and 0 to ll# is used.
．． 05-10 is suitable. Further, it is generally desirable that the thickness of the gasket be the same as or slightly thinner than the thickness of the thickest part of the electrode.

The shape of the gasket is as shown in Figure 1 above.
Although a rectangular frame shape of If is generally used, various forms of a dot-shaped frame as shown in FIG. 2 can also be adopted.

In addition, one or more communication ports (3) are installed on the top and bottom or left and right sides of the gas chamber/mud to allow the solution to flow into the electrode chamber and the solution to flow out from the electrode chamber. Furthermore, in order to uniformly disperse the Ks liquid in the electrode chamber, it is preferable that the gasket is provided with a communication groove and a flow divider plate.The structure of the communication groove and the shape of the flow divider plate are suitable for electrodialysis. The structure used in the tightening electrodialysis tank used in the
K Net of the same metal as the material used, such as titanium, niobium, etc., diagonal font.

A material with protrusions or a sponge material can be used, but a fluorine-containing bulky polymer with corrosion resistance is preferable.Furthermore, in order to prevent the cation exchange membrane from falling into the communication groove, it is not only corrosion resistant but also deforms during long-term use. It is preferable to have none. Furthermore, since the polar liquid is supplied through the communication port, it is necessary to uniformly supply the liquid to each polar chamber. That is, in order to distribute the flow rate equally, it is desirable that there is some degree of pressure filling in this part.

In addition, it is desirable that the porous electrode and gasket be integrated and built-in.
When a polymerized metal material is used for the gasket, it is integrated by fusion, and when the gasket is made of metal, it is integrated by melting**.

(or gasket), if the communication ports are on the top and bottom, press left and right K,
Also, when the communication ports are on the left and right sides, it is necessary to take out busbars for power supply at the top and bottom. Since this is a monopolar electrolytic cell, if there are communication ports at the top and bottom of the gas gut, as shown in Figure 1, the power supply body on which busbars (5) for the anode are scattered should be installed on the left side, and the bus bar (5) for the cathode The shape is such that the power supply body to which the bus bar is attached is mounted on the right side Km. The electrodes are thinner than conventional electrolytic cells, and because they allow a large current to flow through them, the busbar is constructed with as little conductor electrical resistance as possible.

It is necessary to supply current to the power supply and electrode housing parts. Therefore, when using an electrode made of a material such as titanium that has poor electrical conductivity, it is desirable to bring the power supply into explosive contact with the electrode within a range that does not cause deviation of the streamlines, and the voltage drop due to the electrical resistance of the conductor is likely to be low. Desirably, when operating at a current rating of 30 m/dr, it is necessary that the somv or less. Furthermore, since it is a monopolar electrolytic cell, 1 essential K11m
Although the leakage current is small, the length and shape of the communication groove must be selected depending on the type of polar liquid used, and care must be taken to keep the leakage current normally below 1%.

As the fluorine-containing cation exchange membrane of the present invention, perfluorocarbon cation exchange membranes are particularly preferred, and conventionally known membranes can be used. Specifically, barfluo μ (3,
6-Shioxer (4-methyl-7-octensulfonyl fluoride) and tetrafluoroethylene co-heavy metals are layered and hydrolyzed into a membrane, and these membranes with different exchange capacities are adhered and fused. , a blend, or a sulfonamide group, a carboxylic acid group, a phosphoric acid group, which has a dissociated hydrogen atom on one side of the membrane,
A so-called multilayer film having a thin layer of weakly acidic cation exchange groups such as tertiary alkonyl groups such as phenolic hydrochloride and barfluoropolymer is suitably used. Furthermore, those obtained by partially decomposing and removing a part of the peruffle secondary sulfone monomer from one side of the membrane, or those partially inactivated by a chemical reaction are also suitably used. Of course, all known cation exchange membranes in which the cation exchange groups throughout the membrane are perfluorocarboxylic acid groups are effective. In addition, most of the sputum LLI and MWI of the membrane have a large exchange capacity, and only a portion of the cathode side has a low exchange capacity, such as carboxylic acid group membranes and sulfone group membranes, which are also effective. A particularly effective cation exchange membrane has perfluorosulfonic acid groups in most of its thickness, and has an exchange capacity of 0.6 to
2. OJ! 7 equivalents/g dry film H (, Hm'), and carboxylic acid groups are present at a thickness of at least 20 QA' only on the side facing the cathode in an amount of 0.6 to 2.02 g/g dry film (Hm). It is a layered film. In order to maintain high exchange capacity and mechanical strength, a membrane having a partially crosslinked structure is desirable.

In addition, the membrane may contain reinforcing materials such as inert cloth, netting, m-material, etc., but since the membrane is in close contact with both sides of the membrane by the gasket containing the anode and the gasket containing the cathode,
Reinforcements are not necessarily required. When using reinforcement materials,
Polytetrafluoroethylene, FEP, PFA, a copolymer of tetrafluoroethylene and hexafluoropyrene, and the like are preferably used from the viewpoint of chemical resistance and heat resistance.

The most desirable is no reinforcing material and a thickness of 0.03
~2.0 fin cation exchange membrane. When a cation exchange membrane is incorporated into an electrolytic cell, apart from those with a uniform membrane structure, membranes with an anisotropic distribution of ion exchange group types with respect to the membrane cross section will have an exchange capacity of the layer determined by the water content. Where nF &
It is necessary to keep the side with high constant ion concentration facing the gasket containing the cathode. For example, in a two-layer film consisting of a carboxylic acid layer and a sulfone layer, it is necessary to incorporate a layer having a carboxylic acid group toward the cathode side.

The electrolytic cell of the present invention has an anode chamber consisting of a gasket containing a porous anode, a barfluorocarbon cation exchange membrane, a cathode chamber consisting of a gasket containing a non-porous cathode, and a cation exchange membrane and an anode chamber. The unit is 2 units or more, 100 units, although it varies depending on the purpose of use.
It can be carried out industrially even in units of 1000 units depending on the case. The unit is appropriately selected from the viewpoint of stable operation and scale of the equipment, and there is no generation. The terminals of the monopolar electrolytic cell are held by a partition wall made of a corrosion-resistant material for the anode 111C on the anode side, and a material that is corrosion-resistant against the cathode @ on the cathode side, thereby forming one single-pole wrinkled battery cell. This monopolar electrolytic cell can be operated by pressing it from both ends with a hydraulic press, but for convenience in handling the pile, 5 or 10 units are set at one time, and bolts are tightened in small units, and these are connected to multiple sides. It may be stacked to form an electrolytic cell.

When using the electrolytic cell of the present invention, when flowing the solution at a high flow rate in order to quickly and easily remove bubbles from the electrodes and the electrolytic chamber, the solution should be flowed at a high flow rate to eliminate the concentration polarization of the electrode M. When the solution is flowed at a high flow rate, the rate of decomposition of the supplied solute becomes low. Therefore, it is preferable that the electrolytic cell is longer in the upper direction than in the middle direction, and preferably has a length in the flow direction that is 1.1 to 10 times as long as in the width direction. In this case, if the length is too long, it will not be easy to handle as industrial equipment, and the difference in purulence between the inlet and outlet of the container will be too large, resulting in severe non-uniformity of the current. Of course, the electrolytic cells can be installed not only in the stacked direction, but also in the horizontal direction, since the polar liquid is flowing at a high flow rate. Alternatively, you can install multiple identical electrolytic cells and use the polar liquid from the first stage as the second stage.

It may also be run in series with the third stage. Furthermore, for example, the electrolyte leaving one anode chamber in one electrolytic cell may be supplied to the next adjacent anode i1 in the same electrolytic cell, and after passing through a plurality of anode chambers in the same electrolytic cell, It may be discharged from the electrolytic cell.

The electrolytic cell of the present invention is different from any conventionally known electrolytic cell using an ion exchange membrane, its form, and usage mode. It has a structure similar to a clamp-type electrodialysis tank using an ion-exchange membrane, but it has a special anode, a cathode, and an ion-exchange membrane, and each electrode is connected to the solution. It is essentially different from an electrodialysis tank in that it has a special effect of disturbing the flow lines of the cell.

In order to fully satisfy the purpose of the present invention, in the electrolytic cell of the present invention, it is preferable that the porous anode, the fluorine-containing cation exchange membrane, and the porous cathode are laminated in such a way that they are in close contact with each other. That is, in a system that generally uses an ion exchange membrane, a concentration polarized layer is formed at the interface of the ion exchange membrane based on the difference in mobility between ions in the membrane and in the solution. On the other hand, also in the electrode field, concentration polarization occurs due to the difference in mobility of ions in the solution and the difference in electrode reaction. When electrolysis at 411 is performed at a high current density, this concentration polarization phenomenon progresses to a high degree. Normally, in an electrode reaction, gas is generated from the electrode, so the generated bubbles agitate the solution and eliminate the concentration polarization at the electrode interface. Be erased. However, there is a limit to the elimination of concentration polarization by bubbles as described above.
At the same time, the rate at which the gas generated at the electrodes rises due to natural convection is extremely slow depending on the liquid properties, and especially in large-area industrial electrolytic cells, bubbles remain in the electrolytic cell.

This causes an increase in the voltage between the electrodes, which in turn causes a rise in the power consumption rate of the product produced by electrolysis.

To do this, simply eliminate the concentration polarization by air bubbles.

In addition to the rise of bubbles due to natural convection, the concentration polarization is completely eliminated by forcing the electrode solution to flow, and at the same time, the electrode solution containing bubbles is quickly replaced with a solution that does not contain bubbles, and the electrode solution containing bubbles is removed. By repeating the process of separating the liquid solution in a gas-liquid separation tank and supplying the solution without bubbles to the electrolytic tank again, the voltage drop due to concentration polarization and the voltage drop due to air bubbles in the solution are reduced as much as possible. Furthermore, it is possible to completely remove air bubbles that adhere to the membrane surface and allow the current to pass through. In particular, in order to more efficiently eliminate these concentration polarizations, remove bubbles in the solution, and remove bubbles on the membrane and electrode surfaces5, it is necessary that the electrode and ion exchange membrane are in close contact. . If there is an air gap between the electrode and the ion exchange membrane, when the polar liquid is circulated, the solution will pass through the air gap with less pressure loss, and the above-mentioned effect cannot be achieved. Therefore, in the electrolytic cell of the present invention, it is most desirable if the thickness of the electrode and the gasket are essentially the same. It is almost impossible in industrial equipment to have a completely uniform thickness over the fiK. Especially in large area industrial equipment, electrodes and membranes.

It is inevitable that both the gasket and the champion will be slightly different. For this reason, in the electrolytic cell of the present invention, the thickness of the electrode is set to 20% of the thickness of the gasket.
It is desirable to make it thinner than the following. The thickness of the electrode in this case refers to the thickness of the intersection point in the case of wire mesh, and in the case of expanded metal, the thickness of the electrode is 20 degrees compared to the thickness of the gasket. %, the ion exchange membrane, which is a polymer compound, will be deformed and damaged by the metal electrode.

Therefore, the gasket thickness is generally the same as the electrode thickness, or 20%, special KIO%, and 5% more than the electrode thickness.
We have found empirically that thinning is desirable and the limit is less than 20%. When the gasket thickness and electrode thickness are the same to 20%, the shape and hardness of the electrode, the strength and flexibility of the ion exchange membrane are determined as appropriate.

The value is selected depending on the hardness of the gasket, etc.

The electrolytic cell of the present invention is not only an extremely compact and inexpensive electrolytic cell, but also extremely superior in terms of energy consumption. Conventionally, in alkali metal salt electrolysis using an ion exchange membrane, the voltage drop due to the electrical resistance of the ion exchange membrane accounts for a large amount of the electrolysis voltage. Therefore, it is necessary to use a film with as low electrical resistance as possible.

That is, inert materials such as cloth and mesh are used to reduce the thickness of the ion exchange membrane, increase the exchange capacity, and maintain the strength of the ion exchange membrane.

Reinforcing materials such as porous bodies should be removed or reduced as much as possible. In such cases, the mechanical strength of the ion exchange membrane inevitably becomes weaker. However, in the electrolytic cell of the present invention, the cation exchange membrane is supported on both sides by porous electrodes, which makes it possible to use membranes that were previously unusable industrially, and at the same time, from this point of view, there is a significant energy consumption. The amount can be reduced. “In addition, in conventional electrolytic cells, when the gas generated at the electrodes is discharged outside the cell, there is a large amount of gas at the top of the electrolytic cell.
Although there was a liquid mixed layer, in the electrolytic cell of the present invention, this layer is reduced, and the amount of gas contained in the electrolytic cell is smaller than that of the conventional electrolytic cell, which prevents damage to the ion exchange membrane. Even in the event of an explosion, mixing of the polar gases and an explosion can be avoided.

Furthermore, when operating the electrolytic cell of the present invention, the anolyte and catholyte are circulated through one or both of them, thereby eliminating the diffusion film layer formed at the electrode liquid interface and the exchange liquid interface, and eliminating the diffusion film layer formed at the electrode liquid interface and the exchange liquid interface. It is extremely easy to remove the gas generated from the electrolytic cell. That is, in contrast to conventional electrolytic reactions, especially in alkali metal salt electrolysis, where the boundary between the electrode and layer interfaces was destroyed simply by the gas generated at the electrodes, the electrolytic ellipse of the present invention This can be easily destroyed by proper fluid circulation. At the same time, gas was removed from the solution only by the natural rise of the gas generated in the viscous solution, whereas in the electrolytic cell of the present invention, the liquid is forced to flow By replacing the gas-containing solution with a gas-containing solution), the voltage drop due to bubbles can be easily reduced. On the other hand, the reduction in electrolysis voltage in the electrolytic cell of the present invention is extremely remarkable, resulting in a surprising reduction in electrolysis voltage when compared to the electrolysis voltage in conventional electrolytic cells (particularly conventional alkali metal salt electrolytic cells).

In the present invention, the flow rate of the circulating fluid is also extremely important, and is generally used within the range of 1 to 366 oa/sec. If it is too fast, it will be uneconomical in terms of pump power, and In the following, the effect is weak in terms of bubble release action and film destruction action. From this point of view, the polar liquid flow rate is
Preferably it is 2 am/sec or more, more preferably 10 cmZ soft or more and 100 (!ml/2 or less).

Of course, this flow rate depends on the current level, the solution level, the structure of the electrolytic cell,
If this is significantly affected by various factors such as the shape of the electrode, the height of the container, and the ability of gas to escape, and if the shape of the electrode has a large effect of disturbing the flow lines of the solution, then it is not necessary to flow at a faster flow rate. Although a turbulent region is desirable, increasing the solution flow rate so as to create a turbulent region is not economical in terms of pump power. It is necessary to disturb the streamlines and destroy the membrane layer at the electrode and layer interfaces. The flow rate of the anolyte and catholyte can be determined from these five points of view, but it varies depending on various conditions, and also depends on the liquid properties and concentration of the catholyte. Although a flow rate higher than the above is sufficient, there are also other points of view. As a general expression, the gas content in the solution in the anode chamber or cathode chamber is 7.
0% or less, preferably 50% or less, more preferably 30%
It is to be. The flow rate of such solutions, current density,
Other conditions may be selected. In addition, when flowing the polar solution at a high flow rate, both the anolyte and the catholyte may be circulated, but it is also possible to circulate only one of them, or the flow rate of one can be made to flow at a high rate while the other is operated at a lower flow rate. −
You can also do that. In the electrolysis of a 1IIK fulkaline metal salt aqueous solution, bubbles are generated and a boundary film at the anode interface and the cation exchange membrane-liquid interface is likely to grow, and in order to eliminate this, the solution should be flowed at the fastest possible flow rate. There is a need. In addition, a barrier film Vc is formed at the cathode interface, eliminating the diffusion potential and hydrogen gas film surface.

The catholyte must be flowed at a flow rate that takes into account desorption at the electrode interface. In this case, it is necessary to select the flow rate for each chamber by considering the electrode shape and the concentration level in each chamber.

In addition, the electric current when operating the electrolytic cell of the present invention varies depending on the purpose of use of the electrolytic cell, but in the case of alkali metal salt electrolysis, it is possible to reach 5 to 2 G0A/dbi, and in particular, the voltage inside the electrolytic cell High current density 25A due to low drop
It is economical when operating at g0A/d7fi@/d11L'' or higher.Of course, the appropriate current density will vary depending on the energy cost of the location where the electrolyzer is installed, but the current density is higher than that of conventional electrolyzers. Very effective.

Examples using the electrolytic cell of the present invention are shown below, but the present invention is not limited thereto.

Example 1 A polytetrafluoroethylene gasket (with
A porous anode is inserted into the titanium lath material (thickness of the intersection of IIt size is 2.0 to 2.2 wx).
) An insoluble anode activated by coating both sides with ruthenium oxide and titanium oxide was built into 5 with no space between it and the gasket, and the power supply to the anode was brought out from the right side of the gasket. A titanium lath material with the same thickness as the non-activated anode and with a dense lath opening was inserted into the communication groove to create a gasket containing the porous anode. On the other hand, for a gas get with a built-in porous cathode, the gasket is the same thickness and made of the same material as the anode gasket, and one communication port and communication groove are provided at different upper and lower positions than the anode gasket. As a cathode, a soft iron lath material (intersection thickness of 2.0 to 2.2 m) K, P Dan nickel plated and with a cathode overvoltage reduced to about 100 ILV was used, and the power supply was brought out from the left side of the gasket.

The communication grooves were made of soft iron lath material with dense openings that had not been subjected to activation treatment. The cation exchange membrane inserted between these two gaskets is made of tetrafluoroethylene and perfluoroμ (3
, 6-thioxer (4-methyl-7-octensulfonyl fluoride), with a thickness of 7 mils and an exchange capacity of 0.91J/g dry membrane (HIE) after hydrolysis. So, this is JP-A-5B-132069
Approximately 10% of the ion exchange capacity of the membrane was changed to carboxylic acid groups on only one side of the membrane according to the method of .

゛ Place the cation exchange membrane tightly on the gasket containing the porous anode with the side without carboxylic acid groups facing, then place the gasket containing the porous cathode tightly on top of this, and then The above-mentioned cation exchange membranes are stacked with the back side with the carboxylic acid group facing, and then the gasket containing the anode and the cation exchange membrane are stacked alternately to form 5 units, and titanium plates are placed on both sides to form 5 units. Pressed by a hydraulic press.

The power supply plate coming out of each gas get was connected to a positive or negative power source, a 3.5N saline solution was supplied to the anolyte, and a caustic soda aqueous solution of 10N to the cathode chamber was supplied. Electrolysis was carried out at a current density of 30 A/dm'' at 85° C., and the flow rates of the anolyte and catholyte were varied. The results are shown in Table 1.

Note that electrolysis was performed in a conventional monopolar electrolytic cell using the same membrane and electrode. That is, the anode chamber is a monopolar electrolytic cell in which a cation exchange membrane is closely attached to the anode surface, and an air gap of K 4 cm is created behind the anode so that the gas generated at the anode can easily escape and rise. The cathode was placed 4 m apart from the membrane. Furthermore, in order to facilitate the release of hydrogen gas generated at the cathode, an air gap of 4α is formed on the back surface of the cathode. The anolyte and catholyte were the same as those in the electrolytic cell of the present invention, and were supplied from the bottom of the electrolytic cell and overflowed from the top.

Electrolysis was carried out by flowing both the anolyte and catholyte. All other electrolytic conditions were the same, and the results are shown in Table 2.

In addition, in order to measure the gas content in the polar liquid in the electrolytic cell, the polar liquid is circulated at a flow rate of 16 cm/sec, the circulation is stopped during electrolysis, and the gas content of the polar liquid is determined from the amount of the polar liquid in the electrolytic cell. When measured, it was 10%.

Example 2 A gasket having a width of 20 mw, a current carrying area of 120 CI4 in the length direction, and a communication port for supplying the electrolyte at the top and bottom was used to house an anode and a cathode. The gasket for the anode was made using a 3-inch titanium plate, and a rubber sheet made of a copolymer of KO, 25m polypropylene and tetrafluoroethylene was pasted on both sides to improve insulation and sealing. A communication port and a communication groove are provided. The built-in anode is a titanium expanded mesh coated with ruthenium oxide and titanium oxide.

In addition, the maximum thickness of the expanded band mesh is 3.5.
The thickness was ~3.9 m. This was built into the gasket mentioned above, and the periphery was spot welded at several places on the top, bottom, left and right to integrate the gasket and anode, and a lead to the power supply was provided from the right side of the gasket.

On the other hand, the cathode is a nickel expanded mesh with the highest thickness at the intersection of 3.5 to 3.9 mm, and is coated with Kq dunn nickel plating, precious metal plating, etc. to reduce cathode overvoltage. A/di'' was set at 501 mV.

As the gasket for the cathode, a soft iron plate with a thickness of 3 电 was used, and it had the same shape as the gasket for the anode chamber, but had two communication ports in different positions to improve sealing performance and to provide insulation. , a gasket made of the same material as the gasket of the 2sm anode chamber was used and was bonded on both sides. The cathode was built into this gasket in the same way as the anode, and spot welded to integrate it, and a lead to the power supply was provided from the left side of the gasket.

Exchange capacity is 0.91j as a perfluorocarbon-based cation exchange membrane! jfi amount/g Dry membrane () (W), the thickness of the membrane is 0.15μ, and there are several carboxyl groups on the - side over a thickness of 0.02 mm, and other than that, there are no sulfonic acid groups. A membrane with the following properties was used.

The gasket consists of 5 pairs of stacked layers and has an anode built in on the end plate made of titanium plate.

A cation exchange membrane (with the side with sulfonic acid groups facing the anode) was laminated with a gasket containing the cathode. After the gasket containing the cathode was laminated, it was pressed with a soft iron end plate and then pressed using a press machine in both cases.

The left and right power supply bodies were connected to each other, connected to positive and negative currents, and electrolysis of saturated salt water was carried out at a current density of 4 OA/dlK.The salt water supplied to the anode was Flow at a flow rate of 9.0N-
The flow rate was similarly varied with NaOH. Electrolysis temperature is 85℃
Met.

For comparison, an electrolytic cell of the same size is used, but the membrane is supported on the anode like a conventional bipolar electrolytic cell, and the distance between the membrane and the cathode is 4111, so that the back side of each anode and cathode is to 4
A monopolar electrolytic cell with a gap of C1l to allow air bubbles to escape was used. The electrolysis conditions were the same as when using the electrolytic cell of the present invention, and the catholyte and anolyte were flowed at various flow rates. Table 3 shows the electrolysis results using the electrolytic cell of the present invention, and f14 shows the electrolysis results using the conventional monopolar electrolytic cell.

Furthermore, when we measured the gas content in the polar liquid during electrolysis, we found that
When the flow rate is 1 cm/sec, it is 70%, and when the flow rate is 6
It was 40% at ox/sec.

[Brief explanation of the drawing]

FIG. 1 shows an example of a gasket containing a porous anode or a porous cathode used in the electrolysis 411 of the present invention, where l is a gasket, 2 is a porous anode (or porous cathode), 3 is a communication port, and 4 5 indicates a communication groove and 5 indicates a power supply plate, respectively. Further, FIG. 2 shows a tortoise 7p-type gasket having a built-in porous anode or porous cathode according to the present invention, and 1 is the gasket. 2 is a porous anode (or porous cathode), 3 is a hole, 4
indicates the power supply. Patent Applicant: Tokuyama Ichigo Co., Ltd. Figure 1

Claims (1)

[Scope of Claims] 0) A monopolar carbon dioxide electrolyte ( 2) The single tsi electrolytic cell according to claim 1, characterized by a porous anode, a fluorine-based cation exchange membrane, and a porous cathode. A monopolar carbon electrolyzer (4) according to claim 1, in which the thickness of Gaoka-1 or the gasket is reduced by 20%. Electrolytic cell (5) Anolyte and/or catholyte
Claim 3: Electrolyzing by flowing at a flow rate of 7wt or more
Monopolar electrolyzer described in section