JPS59200776A - Electrolyzing method and electrolytic cell used therefor - Google Patents

Abstract

PURPOSE:To perform electrolytic refining with good efficiency and simple modification in the stage of modifying a mercury method electrolytic cell for an NaCl soln. to a cation exchange method electrolytic cell by inclining an exchange membrane method electrolytic cell by inclining an exchange membrane to a specific angle and discharging the gaseous H2 generated in a cathode quickly from the cathode chamber by the gas lifting effect. CONSTITUTION:An electrolytic cell is segmented to an upper anode chamber 1 and a lower cathode chamber 2 by means of a cation exchange membrane 3 and insoluble anode plates 8 and a metallic cathode 9 constituting the bottom of the chamber 2 are installed respectively in parallel with the membrane 3 in the stage of modifying a mercury method electrolytic cell for an NaCl soln. to a cation exchange membrane method electrolytic cell without discarding the cell as scrap. The membrane 3 is inclined at the angle within the range where a gas lifting effect arises in the gaseous H2 generated in the chamber 2. The mixed gas-liquid phase liquid contg. NaOH and gaseous H2 is discharged through a port 14 in a high position of the chamber 2, and the catholyte separated of the gaseous H2 in a gas-liquid separating tank 16 is automatically supplied through a conduit 21 into a catholyte introducing port 13 by utilizing the fall thereof. The electrolytic refining is thus accomplished with good efficiency without the need for many pipings, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION The present study mainly relates to a 1Jf solution method for an alkali metal halide bath solution, especially a JfA alkali salt solution, and an electrolyzer 11 used therein, and more specifically, the scum lift effect of cathode gas and the head difference. Regarding an electrolytic method and an electrolytic device that aims to simplify the device, reduce the varnish, and further improve the production 1''t per unit floor area by circulating the catholyte at a pressure of 1-1. It is.

The most typical type of horizontal electrolyzer is the mercury method electrolysis tank, which has been widely used because it yields a hydroxide solution with a relatively high degree of %D. However, since the water 1R used for the cathode is an environmental pollutant, it is destined to be discontinued in the near future. By the way, the mercury method that has been widely used in the past [F solution 4: jlj+ and! ! (= Scrapping all I-band equipment is not at all desirable from an economic or industrial policy perspective, but it is also an extremely serious problem for the industry.) ? It is extremely desirable to convert the H1ji and its ancillary equipment to other safe electrolytic cells without scrapping them.

From this point of view, the present applicant has conducted intensive research to develop a technique that can advantageously convert the mercury method electrolyte to the cation exchange membrane method 7
4J and filed a patent application (patent application 1982-
131377 etc.).

However, when the horizontal electrolyzer is converted to a cation exchange membrane electrolyzer, there is a fatal problem in that the production per unit electrolyzer is drastically reduced. That is, in the mercury method electrolyte, the current density is generally around 100 A/d2, whereas in the cation exchange membrane method, the flow rate is set to 1 due to membrane resistance. When it increases, the voltage increases (”;
5 <, so −・monthly 50△/(J, nl J
The presentation of melon stops at -. Therefore, the production per unit electrolytic cell is 11 (11
′- will be decreased.

- power, water' + t-q + ν electrolysis (11) circulates the catholyte at high speed +3:'i, and efficiently transports the gas stationary in the cathode chamber to the outside, requiring complicated piping and equipment. equipment and operating costs increase, and i
i'e product becomes interesting. Furthermore, since the anolyte normally flows through the anode chamber toward the exit, the salt concentration and PL distribution occur in the direction of flow, resulting in an increase in electrolysis voltage, a decrease in current efficiency, etc. There is a problem of inviting

In view of these circumstances, the inventors of the present invention believe that all of the above problems can be solved by effectively utilizing the gas lift effect and the head (-\sod pressure), and by adopting a four-point resistance plate. This research has been completed based on this knowledge.

That is, the first part of the wood is divided into an upper anode chamber and a lower cathode chamber by a cation exchange membrane stretched with an inclination 1-, and the anode plate and the gas/liquid egg Jf1. Using an electrolytic cell in which the cathode plates are arranged approximately parallel to the cation exchange chamber 71, 1) the catholyte is removed by the gas lift effect of the cathode gas generated in the cathode chamber described in 1).
After the catholyte gas and catholyte are separated by the gas-liquid separation means, the catholyte is transferred to the cathode again by using the head (・\t゛pressure). (-1) The second aspect of the present invention is that the upper anode chamber and the lower cathode are separated by a cation exchange membrane stretched at an angle. The anode chamber has an anode plate arranged approximately parallel to the cation exchange membrane, and includes a lid body, an anode chamber side wall surrounding the anode plate, and a cation exchange membrane. The cathode chamber is surrounded by the upper surface of the exchange membrane and includes an anolyte inlet and an anode gas discharge port as well as an anode gas discharge port, and the cathode chamber is substantially parallel to the cation exchange membrane. The scum that was placed
The cathode chamber is surrounded by a liquid egg permeable electrode plate, a side wall of the cathode chamber surrounding the cathode plate, and the lower surface of the cation exchange membrane, and the catholyte inlet is inclined by mJ. 1
In the ゛ part, the mixture of cathode scum and catholyte) ll I liquid υ
fffl flBI! The gas-liquid fraction is 141 [later cathode? (It is equipped in a position sufficient to allow circulation in the polar chamber, and 1 method has a gas-liquid content of 141 ((J
・An electrolytic device 1 consisting of a configuration in which 11j is connected to the catholyte iA person [-1] by a dedicated tube.

In the following, the present invention will be explained based on drawings showing embodiments of the present invention. In the following explanation, the most common alkali metal halide, sodium chloride, and its decomposition product, caustic soda, are used for convenience, but the present invention is not limited by these. It goes without saying that the present invention does not represent the intention to do so, but it can be immediately applied to other inorganic potassium chloride solutions such as Lycium lily 1 water 1'8 solution and water electrolysis.

FIG. 1 is a schematic diagram showing an embodiment of the apparatus of the present invention.

The anode chamber (1) includes a lid (4), an anode plate (8) arranged approximately parallel to a cation exchange membrane (3) stretched in an inclined manner,
An anode chamber side wall (5) surrounding the anode plate (8)
) and the two sides of the ion-exchange membrane (3), and the anolyte inlet (1) and the catholyte υ[-1(
The anode plate (8) is connected to the cover body (#fi) by the anode conductive rod (6).
4). Each anode conductive rod (6) is electrically connected to each other by an anode bus bar (7). Of course, the anode plate (8) can also be suspended by other methods, and may also be suspended by an anode suspension device 1't for a water-containing electrolyzer.

As the lid body (4) and the anode chamber side wall (5) constituting the above-mentioned anode chamber (1), a part of the lid body and the anode chamber side wall made of mercury method electrolyte (74) may be reused. In addition, any material that is resistant to chlorine can be suitably used without any particular limitations.For example, chlorine-resistant metals such as titanium and titanium alloys, fluorine-based polymers, hard rubber, etc. can be used.Furthermore, the above-mentioned metals can be used. It is also possible to use iron lined with fluorine-based polymer, hard rubber, or the like.

The anode plate (8) for carrying out the anodic reaction can be a graphite anode, but it is also possible to use a metal such as titanium or nontal, for example with a coating containing platinum group gold or platinum group metal oxide or a mixture thereof. The applied cold bath anode is ideal for IT. Of course water 5] I! θ,′1u solution J: H1
The anode plate used in No. 9 can be used by slightly modifying the anode plate. Also, the anode plate can be either permeable or non-permeable.

Next, the cathode chamber (2) includes a gas-shielding, non-permeable cathode plate (9) arranged substantially parallel to the lower surface of the cation exchange membrane (3) and the catholyte. It is defined by a cathode chamber side wall (1 section) erected to surround the cathode plate along the edge, and a catholyte introduction section (13) and a catholyte and cathode gas mixture 1.j'' eyelid. The side wall of the cathode chamber can be made of something like a frame rim to give it rigidity, or it can be made of elastic backing material such as rubber or plastic. It is also possible to configure it with something like this.

In addition to the materials mentioned above, there are no particular restrictions on the materials for the cathode chamber side walls, as long as they are materials that can withstand caustic alkalis such as caustic soda, iron, stainless steel, nickel, and nickel alloys. You can use j. Moreover, a material in which an iron-based tree is lined with alkali-resistant in*1 can also be suitably used. Furthermore, 4-layer materials such as mata rubber and plastic can also be used. 71-month ('A month is, for example, natural rubber, butyl rubber, ethylene propylene rubber)
Rubber threads such as EPH); Polymer I2 material, PoIJ Jj, j.

PVC, reinforced plastic (is”, Ii<P)
i is exemplified.

Gas/liquid valve permeable cathode plate (9) used in the present invention can be made from electrolytic materials such as hard nickel and stainless steel. Mercury method'i1. The bottom plate of L solution J4jlj may be smoothed as necessary to serve as a gas/liquid valve permeable cathode plate, and the gas/liquid valve permeable cathode plate (9) is installed on the second nuclear bottom plate (9) using G close-up. It's okay. The surface of the gas/liquid valve permeable cathode plate (9) was coated with a mixture of the following: , by plating '19, water 2
(It is preferable to perform the overvoltage low F treatment.

1 Wu Mi i The HIB is set up accordingly.

The cation exchange membrane (3) is installed obliquely. Trouble 1;1
The angle is not particularly limited as long as the gas lift effect of the cathode gas generated in the cathode chamber can be obtained.

If the oblique angle is too small, the gas lift effect will not be sufficient; on the other hand, if the angle is too large, it will be costly to manufacture or modify the electrolytic cell, which is not a good idea. Furthermore, by installing the cation exchange membrane at an angle, the membrane area per unit electrolytic cell increases, thereby making it possible to increase production capacity.

There are no particular limitations on the means for installing the cation exchange membrane at an angle, but it is also possible to fix one end of the membrane to the lower flange of the anode chamber side wall (5) and the other end to the upper flange. .

Examples of cation exchange membranes suitable for the present invention include membranes made of perfluorocarbon polymers having cation exchange groups.

A membrane made of a perfluorocarbon polymer having a sulfonic acid group as an exchange group is manufactured by E.I. Dupont Company (E, 1.Du P.
ont de Nemours & Cornpany
) and is commercially available under the trade name "Nafion".
Its chemical structure is as shown in the following formula.

A suitable equivalent weight of such a cation exchange membrane is 1,000 to 2,000 - preferably 1.1.00 to 1.500.
, where the equivalent weight is the weight (g) of the dry membrane per equivalent of exchanged ants. Further, cation exchange membranes in which part or all of the sulfonic acid groups of the above-mentioned exchange membranes are replaced with carboxylic acid groups and other commonly used cation exchange membranes can also be applied to the present invention. Exchange these cations! l＞′! Jη has a small ice-water ratio, and only allows water to pass through, having 13 to 4 water particles, without allowing hydraulic flow to pass through.

1. The catholyte outlet θ8 of the Oiwake tank is connected to the mixed liquid lid outlet (14). 2J): The cathode I is connected to the inlet 1 (13).

The air fraction MII'f' (6) is mixed with the catholyte by the near rise of the electrode gas in the cathode chamber, and the resulting mixture (fl is mixed with the catholyte) The cathode gas is allowed to flow out from the cathode waste outlet θ for 1 minute, and the catholyte is allowed to fall from the catholyte outlet 08). ), it is preferable to install the catholyte at a position sufficient to supply the catholyte to "1 (1)" and circulate the catholyte. If necessary, the corresponding portion 141 [tank Q, 6] is connected to the tank 4". It is also possible to install it several meters above the liquid discharge port 1α4) and use the difference in specific gravity between the mixed liquid and the gas-free catholyte to improve the circulation effect. Furthermore, it is low when driving! i: Flow'f: If sufficient gas lift effect cannot be obtained due to
1 tube (21) can help circulation.

In addition, in Figure 1, gas/liquid calculation permeation 1 housing cathode plate (9)
Although it is supported by the top of the tilt support wall (supported by the top of the bottom plate), the main point is that the cathode plate (9
) is sloping B/I formation, even if it is a force or form.

FIG. 2 is a schematic diagram showing another feature of the device fL of the present invention, showing an example in which the anode plate (8) is made of a non-permeable anode plate like the cathode plate.

In the anode chamber (1) of this device, as in the case of the cathode chamber, the anolyte is made to rise due to the gas reflux effect of the anode gas generated in the anode chamber (1), and the anode gas and the hot water electrode R are brought together. A mixed flow of 1:11 is discharged from the anode mixed liquid outlet (23), and then the anode gas and the anolyte are separated by the anode gas-liquid separator (24). It can be used and circulated again into the anode chamber. This circulation spreads tens of 771' in the yellow direction, for example, in the vertical direction of the anode chamber of the electrolytic cell of the present invention converted from mercury method electrolysis 4 (: In this case, it is possible to prevent the accumulation of anode scum between the cation exchange membrane and the anode, thereby contributing to the reduction of the electrolytic voltage. As in the case, min!jl
lll l'! '! (24) from the anode mixture υ 1 out 1 (23) several meters-1 on one side and 1 submersion 1, using the ratio of the anolyte that does not contain any gas to the ratio of the anolyte that does not contain gas. The effect of circulation can be further enhanced.

FIG. 3 is a schematic back view showing still another embodiment of the device of the present invention, in which a baffle plate (25) is provided above the anode plate (8) and approximately parallel to the cation exchange membrane (3). In Figure 3, the catholyte circulation path is omitted. Figure 4 is a schematic plan view showing an embodiment of the baffle plate. It is installed so as to leave a space (26).

With this configuration, the anode gas generated on the anode plate (8) rises and collides with the baffle plate (25), rises along the lower surface of the baffle plate (25), and reaches the anode gas outlet (
1o). On the other hand, the anolyte flows through the anode chamber while raising the anode gas, passes through the anode back chamber (27) 7, and descends along the top surface of the baffle plate (Z5), creating a circulating flow of anolyte around the baffle plate. occurs, and the anolyte concentration is made uniform. The baffle plate is made of chlorine-resistant paulownia wood, and preferably has the same pattern as the side wall of the anode chamber. Although Figure 3 does not illustrate the electrical connection method between the anode plate and the anode busbar,
As in FIG. 1, the anode may be suspended from the lid (4) by an anode conductive rod. In this case, it goes without saying that the baffle plate (25) must have a hole (not shown) through which the conductive rod (6) passes.Gas escapes between the conductive rod (6) and the hole, resulting in a gas lift effect. It is necessary to have a structure with no gaps so as not to reduce the

FIG. 5 shows another embodiment of the device of the present invention, in which the anode chamber is filled with anolyte, and the mixed phase liquid of anode gas and anolyte is installed in the conduit (22) in two parts. The anolyte is transferred to a heated gas-liquid separation tank where gas and liquid are separated, and the anolyte is again supplied to the anode chamber (1) through the anolyte conduit (22).

As mentioned above, according to the present invention, complicated piping and equipment are not required, so the equipment cost can be reduced.
Natural circulation of the 'tlf decomposed liquid is also possible, and the circulation cost can be reduced to i-+. Also horizontal type 1. If to electrolytic cell ratio, unit electrolysis]・j! j, l! 5
It can increase Rino's life +jn, f+k, and its useful tel is extremely human.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing an embodiment of the electrolytic cell of the present invention and an example of the catholyte circulation system, and FIGS. 2, 3, and 5 show the anode chamber structure and the anode (g, 4 is a schematic plan view showing an embodiment of the baffle plate used in the present invention. 1... Anode chamber 2... Cathode chamber 3・・・
- Cation exchange membrane 4... Lid body 5... Anode chamber side wall 6... Anode conductive rod 7... Anode bus bar 8... Anode plate 9... Gas/liquid egg permeation injection cathode plate 10...・Anode gas outlet 11...Anolyte inlet 12...Anolyte outlet 13...Catholyte inlet 14...Cathode mixed phase liquid outlet 15...Cathode chamber side wall 16...Cathode gas Liquid separation tank 17... Separation tank cathode gas outlet 18 - Separation tank catholyte lII pressure 11
9... Slope support wall 20... Bottom plate 21...
Cathode liquid conduit 22... Anolyte liquid conduit 23... Anode mixed phase liquid outlet 24 ・Anode gas/liquid chamber F chamber 25
...Baffle plate 26...Baffle plate space!
...Anode back chamber Patent applicant Kanebuchi Chemical Industry Co., Ltd. Figure 3 Figure 5

Claims (1)

[Scope of Claims] ■.1 by means of an inclined cation exchange membrane.
It is divided into a part of the anode chamber and a lower cathode chamber, and an anode plate and a gas/liquid impermeable electrode plate are respectively arranged in parallel with the cation exchange membrane, and the "electrolytic 4" tlM The catholyte is raised by the gas lift effect of the cathode gas generated in the cathode chamber, and the catholyte is separated from the catholyte by the gas-liquid separation means. An electrolytic method characterized by utilizing and circulating the cathode chamber again. 2. The '1E solution method according to claim 1, wherein the anode plate is permeable to gas and liquid. 3. The electrolysis method according to claim 1, wherein the anode plate is permeable to gas and liquid egg. 4. The 'l'ti solution method according to claim 3, in which the anolyte is circulated in the tank by providing a baffle plate above the anode plate substantially parallel to the cation exchange membrane. 5 The anode chamber is divided into two anode chambers and a lower cathode chamber by an inclined cation exchange membrane, and the anode chamber has an anode plate arranged substantially parallel to the cation exchange membrane. , surrounded by a lid body, an anode chamber side wall surrounding the anode plate, and the upper surface of the cation exchange membrane, and equipped with an anolyte inlet, a discharge port, and an anode gas discharge. Become,
The cathode chamber is surrounded by a gas/liquid egg permeable cathode plate arranged approximately parallel to the cation exchange membrane, a side wall of the cathode chamber provided around the cathode plate, and a lower surface of the cation exchange membrane. The cathode chamber is formed with an inclined catholyte inlet, and a cathode gas and catholyte mixture discharge port is provided in the upper part of the cathode chamber. 1) The gas-liquid separation tank is connected to the catholyte inlet via a conduit (71.); Naru゛:'tL+Il/lj device. 6. Patent that allows the anode plate to pass through gas/R
1. The device according to item 5. 7. A device in Section 1, Section 5, Section 5, Section 5, Section 1, of Labor Claims, in which the anode plate is gas/liquid permeable. 8 Add 1 model of moxibustion and about 11 of cation exchange to -L power of anolyte (
1. I don't like drinking alcohol. fc,'r,'j u'F *
The device 1 that supports ff17 term 3self i1 immediately outside the T equation 1. 't
.