JPS59197584A - Horizontal type electrolytic cell - Google Patents

Abstract

PURPOSE:To facilitate conversion from a mercury method electrolytic cell and to shorten an operation stop time required in the replacement of a membrane by making membrane replacement efficient, by partitioning the cathode chamber of a horizontal type electrolytic cell using a cation exchange membrane into a plurality of cathode chamber units. CONSTITUTION:In a cathode chamber 2 consisting of a plurality of cathode chamber units 2a partitioned in the longitudinal direction, each unit 2a is demarcated by the lower surface of a cation exchange membrane 3, a cathode plate 12 and a cathode chamber side wall 17. An anode chamber 1 may be constituted alone or of a plurality of anode chamber units 1a and each unit 1a is demarcated by a lid body 4, an anode chamber side wall 5 and the upper surface of the exchange membrane 3. Brine is introduced from an anode liquid introducing port 13 and generated cholorine gas is exhausted from an anode gas exhaust port 15 while low concn. brine is discharged from an anode liquid discharge port 14. On the other hand, a cathode liquid is introduced from a cathode liquid introducing port 19 and discharged as a mixed phase liquid stream with generated hydrogen gas from a cathode liquid discharge port 20.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention mainly relates to an aqueous solution of an alkali metal halogenide,
In particular, it relates to an electrolytic cell for an aqueous alkali chloride salt solution. More specifically, the present invention relates to a horizontal electrolytic cell using a cation exchange membrane as an electrolytic diaphragm, and in which a cathode chamber is partitioned into a plurality of cathode chamber units.

A horizontal electrolytic cell is divided into an upper anode chamber and a lower cathode chamber by a horizontally stretched diaphragm. The most typical type of horizontal electrolyzer is a mercury-based electrolyzer, which has been widely used because it contains a relatively high concentration of hydroxide (IJKum solution). However, because the mercury used in the cathode is an environmental pollutant, it is destined to be discontinued in the near future.

By the way, scrapping all of the mercury electrolytic cells and ancillary equipment that have been widely used in the past is not at all desirable from an economic or industrial policy standpoint, and on the other hand, it is also an extremely serious problem for the industry. Under such circumstances,
It is highly desirable to convert mercury electrolytic cells and associated equipment to other safer electrolytic cells without scrapping them.

From this perspective, the applicant has conducted extensive research and has developed a technology that can advantageously convert a mercury-based electrolyzer into a cation-exchange electrolyzer, and has previously filed a patent application (Japanese Patent Application No. 57-131).
377 etc.).

By the way, horizontal electrolytic cells are characterized by being large in the horizontal direction. For this reason, it is necessary to use a large membrane, but the size of the cation exchange membrane is generally limited by the manufacturing equipment, so the reality is that several membranes are joined together to form a large membrane. However, it is not always easy to bond cation exchange membranes that can withstand the harsh conditions of electrolysis for a long period of time. Furthermore, because of the large size of the membrane, it is difficult to transport and handle, and even if one part is damaged during use, the entire decomposition tank must be dismantled. Furthermore, when attaching the membrane, pretreatment is performed by soaking it in salt water containing ethylene glycol, but not only does this treatment require a large treatment tank, but even a small elongation rate reduces the overall size of the membrane. This can greatly affect the appearance of wrinkles. In addition, there is another problem in that it is difficult to form a uniform flow of catholyte on the membrane surface.

In view of the above-mentioned circumstances, the present invention attempts to fundamentally solve these problems.

That is, in the present invention, a cation exchange membrane stretched substantially horizontally is divided into an upper anode chamber and a lower cathode chamber, and the anode chamber has a substantially horizontal anode plate. It is surrounded by a lid, an anode chamber side wall surrounding the anode plate, and the upper surface of the cation exchange membrane, and has one hot water tap at the anolyte inlet and outlet. The cathode chamber is formed between the lower surface of the cation exchange membrane and one electrode plate, and is partitioned into a plurality of cathode chamber units by a side wall of the cathode chamber and/or a frame edge. The electrolytic cell is a horizontal type electrolytic cell having a structure including a cathode e inlet and a mixed phase liquid outlet of catholyte and cathode gas.

The present invention will be explained based on drawings showing a first embodiment of the present invention.

FIG. 1 is a front sectional view of a horizontal electrolytic cell composed of a plurality of cathode chamber units each having a cathode chamber partitioned in the length direction, and FIGS. 2 and 3 are side sectional views of the same. In this example, not only the cathode chamber but also the one-field pole chamber is composed of a plurality of anode chamber units.

As shown in FIGS. 1 to 3, the anode chamber unit (1) includes a lid (4), an anode chamber side wall (5) extending to surround the anode plate α, and a cation exchange 11% It can be seen that the upper surface of (3) is machined and defined, and the positive plate rod (6) is connected to the lid body (4).
7) and 14. Each anode conductive rod (6)
Ku (8) makes each other feel nauseous 1. It is connected to FJ. The lid body (4) has a hole through which the lift pole cover (9) is inserted, and the chain hole (10) is hermetically sealed by a hole (10).

An anode plate a2) is attached to the lower end of the anode conductive rod (6), and thus the anode plate a is connected to the anode suspension device (7), so that the anode suspension device (7) cannot be operated. , J: Can be adjusted up and down, and has a cation exchange membrane (3
) can be placed in contact with the

However, the anode plate is not limited to being suspended from an anode suspension device provided upright on the lid, and may be suspended or supported by other methods. Furthermore, the anode chamber has at least one anolyte inlet α, which can be provided on the lid (4) or on the side wall (5) of the anode chamber. On the other hand, at least one anolyte outlet (14) is provided, and these can be provided in the side wall (5)K. Also, the lid body C4)! Alternatively, an anode gas (chlorine gas) outlet 00 is provided at an appropriate location on the side wall (5).

As the lid body (4) and the anode chamber side wall (5) constituting the above-mentioned anode chamber unit (1), it is sufficient to reuse the lid body and anode chamber side wall constituting the mercury electrolytic cell. Any material can be suitably used without any particular restrictions as long as it can withstand the above. For example, salt-resistant purple metals such as chikun and titanium alloys, fluorine-based polymers, hard rubber, etc. can be used. Furthermore, the above metal, fluorine-based polymer 1'I?
For c, iron lined with hard rubber or the like can also be used.

Although a graphite anode can be used as the anode plate q for carrying out the anodic reaction, a 4-soluble anode made of a metal such as titanium or quantal and coated with, for example, a platinum group metal or a platinum group metal oxide or a mixture thereof may also be used. preferable. Of course, it is economical to use an anode plate of the same size and shape as used in a mercury electrolyzer.

Next, the cathode chamber unit (2) includes the lower surface of the cation exchange membrane (3), the cathode plate a, and the cathode chamber side wall α built up along the edge of the cathode plate so as to surround the cathode plate. ni, J:l,
! be configured. The side wall .alpha..eta. of the first mantle chamber can be made of a material such as a frame edge that provides rigidity, or may be made of a banking-like elastic material such as rubber or plastic that provides some elasticity.

In addition to the above-mentioned materials, there are no particular restrictions on the material for forming the α-force on the side wall of the cathode chamber, as long as it is resistant to caustic alkalis such as caustic soda, and iron, stainless steel, nickel,
All nickel alloys etc. can be used. A material obtained by lining an alkali-resistant material on an iron base material can also be suitably used.

Materials such as rubber and plastic can also be used. Examples of such materials include rubber-based materials such as natural rubber, butyl rubber, ethylene propylene rubber (EPR) 7Z, tetrafluoroethylene polymer, tetrafluoroethylene-hexafluoropropylene copolymer, and ethylene-tetrafluoroethylene copolymer. Examples include fluoropolymer materials such as fluorine-containing polymers, polyvinyl chloride, and reinforced plastics (FRP).

The collapsible cathode plate head used in the present invention can be made of conductive material such as iron, nickel, stainless steel, etc., J:5.

Furthermore, it is extremely economical to reuse the bottom plate of a mercury electrolyzer. In a preferred embodiment, the surface of the cathode plate is subjected to hydrogen overvoltage reduction treatment by plasma spraying, plating, etc. of nickel, platinum group metals, alloys thereof, or mixtures thereof.

The catholyte inlet (Igl) and the mixed liquid outlet (e) need only be capable of producing a flow of the mixed phase liquid within the cathode chamber unit (2).For this purpose, for example, a catholyte header (2) ]) Or, it is convenient to discharge the 6-electrode liquid and the mixed-phase liquid to each cathode chamber unit (2) using the 9 branch tubes.In Fig. 2, the cathode A case is shown in which the plate is placed in a direction approximately perpendicular to the horizontal direction of the plate and discharged in a substantially vertical direction.If the entire bottom plate of the mercury method electrolyzer is to be used as the electrode plate of the present invention, it is necessary to prepare a perforated plate in advance. The bolt holes in the hole can be used as the inlet or outlet by appropriately processing them. Figure 3 shows the connection between the cation exchange membrane (3) and the cathode plate. This is an example in which all the walls of the cathode chamber, the inlet and the outlet are all in use.

No. 4171 is a partially cutaway front view of a horizontal electrolytic cell composed of a plurality of (two in the figure) cathode chamber units partitioned in one direction, and FIG. 5 is a side sectional view of the same. In this example, not only the cathode chamber but also the anode chamber is composed of a plurality of (two) anode chamber units (1), and the catholyte is circulated in the width direction within each cathode chamber unit (2). It is configured.

Figure 6 shows a structure partitioned in the width direction as shown in Figures 4 and 5, but the circulation of one cathode chamber unit (two
) in the longitudinal direction VC.

FIGS. 7 and 8 show an example in which the cathode chamber is made into a plurality of cathode units by arranging frame edges (2) for partitioning the cathode plates at appropriate intervals in the longitudinal direction on the cathode plate (10). In this example, the anode chamber is composed of one unit. Fig. 7 is a plan view, and Fig. 8 is a front view of the same, in which cation exchange membranes (3) are attached to form a plurality of cathode units. In the same figure, a bolt (4) is inserted between the frame edge placed on the cathode plate (LQ) and the holding plate (c) through the seal.
, a J:v cation exchange membrane (3) is sandwiched, and is defined by a cathode chamber side wall 1.17), a frame rim, a cathode plate U, 6) and a return (3). 1 electrode chamber unit (2) and opposing frame edge (toward) [and packing], cathode plate α6
) and III (3), a polar chamber unit (2) defined by σ is formed. Fig. 9 shows another situation in which two ion exchange plates (3) are attached to each other on the same plane [1'Ji between the packing frame and the frame frame 4].

FIG. 10 shows still another embodiment, in which a window frame-like frame edge (24a) is used for a plurality of openings (A), and a window frame-like holding plate (25a) is used for a plurality of openings (A). A cation exchange membrane (3) is sandwiched and fixed between the two through a gasket (not shown), thereby forming a plurality of yin-hu units.

The frame edge (24,a) is made of an alkali-resistant material, such as iron, stainless steel, titanium,
Fluorine-based synthetic resins, rubber, etc. are preferred, and in particular, when an elastic body such as rubber is used, there is no need to interpose a packing between the membrane and the membrane, and the work efficiency can be increased accordingly. on the other hand,
The holding plates (c) and (25a) are made of the above-mentioned alkali-resistant material, but iron, stainless steel, titanium, fluorine-based synthetic resin, etc., which have high rigidity, are suitable. In this case, if a gasket is inserted between the holding plate and the membrane,
By adhering a gasket to the hard surface of the holding plate in advance or lining it with a soft material such as rubber, it is advantageous to be able to omit the trouble of installing a gasket.

Incidentally, the bolt for clamping and fixing may be a normal bolt/nut or an embedded bolt, but since it is exposed across both the cathode chamber and the anode chamber, it is necessary to perform insulation treatment. For example, it is preferable to use non-conductive bolts or to cover the exposed parts of both poles or the exposed part of the anode chamber with a non-conductive material such as rubber or plastic.

In addition, the frame edge (24, 24a) and the presser plate (25+ 25a)
) are both conductive materials, non-conductive bolts must be used.

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

Perfluorocarbon 11 having a sulfonic acid group as an exchange group
As mentioned above, the membrane formed by the combination was manufactured by E.I. DuPont de Nimoas & Campa=-(E,
, Du Pont de Nemours & Co+n
It is commercially available under the product name "Nafion" and its chemical structure is as shown in the following formula.

A suitable equivalent weight of such a cation exchange membrane is from 1.000 to 2,000, preferably from 1,100 to 1.500, where the weight of the dry membrane per exchange group is Heavy Mv). Cation exchange membranes in which part or all of the sulfonic acid groups of the above-mentioned exchange membranes are converted to carboxylic acid groups and other commonly used cation exchange membranes can also be applied to the present invention. These cation exchange membranes have a very low water permeability, and only allow sodium ions to pass through 3 to 4 water molecules without allowing hydraulic flow to pass through. In the present invention, in addition to the above-mentioned films, a so-called non-adhesive type film,
For example, double-sided coating and SPE (Solid)
Polymer Electrode) can also be used.

9. According to the present invention, a mercury electrolyzer can be easily converted to a cation exchange membrane type electrolyzer, and it can be used not only for electrolyzers but also for bus bars, rectifiers, salt water equipment, iodide water treatment equipment, etc. It is possible to effectively repurpose existing maintenance equipment without scrapping it.

Furthermore, according to the present invention, (1) adhesion is not required, so cation exchangers that cannot be bonded, such as double-sided coating I and S;
PE can be used. ■It is efficient because the membrane can be replaced by simply removing the frame in the area where the hole is crossed over and damaged, reducing the time required for operation to be stopped due to replacement. ■Compared to large single-layer membranes, wrinkles are less The occurrence of )8
It has many advantages such as small processing tank, easy transportation and handling, and its practicality is extremely high.

[Brief explanation of drawings]

Fig. 1 is a front sectional view showing a 1M model of the electrolytic cell of the present invention, Fig. 2 is a side sectional view of the same, Fig. 3 is a side sectional view showing another model of the electrolytic cell, and Fig. 4 is a sectional view of the same. Furthermore, a partially cutaway front view showing another implementation mode, FIG. 5 is a side sectional view of the same, and FIG. 6 is another IA
FIG. 7 is a plan view showing yet another implementation seat, FIG. S8 is a front view of the same, FIG. The figure shows yet another implementation 1
FIG. 2 is a perspective view showing an island. 1 ・Anode chamber 2・・i Cathode chamber 3・・Cation exchange j Han 4° Lid 5゛°・Anode chamber side wall 6゛Anode conductive rod 7 Anode suspension device 8 Anode bus bar 9 Anode conductive rod cover 10
Hole 11・Note 12・Anode plate 13゛Anode I+1 Le humiliation inlet 14 Anolyte discharge port】5°Anode gas discharge port 16・Cathode plate 17・Cathode chamber side wall
18; Differential bus bar 19/Negative liquid 7 Entrance 20
1. Extremely liquid outlet 21 ゛Header exclusively for polar liquid 22
Multiphase liquid discharge header 23 ・Packing 24
・(Protrusion 24a Window frame-shaped frame edge 25... Holding plate 25a Window frame-shaped holding plate 26・Bolt 27...Opening patent applicant Kanebuchi Kagaku Kogyo Co., Ltd.

Claims (1)

[Claims] 1. A cation exchange membrane stretched substantially horizontally, J:
The anode chamber is divided into an upper anode chamber and a lower cathode chamber. , and the upper surface of the cation exchange membrane, and is provided with an anolyte inlet and a discharge port, as well as an anode gas outlet, and the cathode chamber is formed between the lower surface of the cation exchange membrane and the cathode. A structure formed between the cathode chamber unit and the cathode chamber unit, partitioned into a plurality of cathode chamber units by a cathode chamber side wall and/or frame edge, and equipped with a catholyte exclusive inlet and a mixed-phase liquid discharge port of catholyte and cathode gas. horizontal electrolyzer. 2. The electrolytic cell according to claim 1, wherein the cathode chamber is composed of a plurality of cathode chamber units partitioned in the width direction of the cathode plate. 2. The electrolytic cell according to claim 1, wherein the electrolytic cell comprises a plurality of cathode chamber units each having a 3° cathode chamber partitioned in the length direction of the cathode plate. 4. Claim 1 in which the cathode chamber consists of a plurality of cathode chambers partitioned in the width direction and length direction of the cathode plate
Electrolytic cell described in section.