JPS5881983A - Bipolar type electrolytic tank - Google Patents

Abstract

PURPOSE:To provide a bipolar type electrolytic tank having improved electrolytic effect, by arranging a plurality of composite electrode plates in a recurring unit in such a manner that polarities of the composite electrode plates in the recurring unit opposed in adjacent relation so that a cation exchange membrane is interposed therebetween have opposite polarities. CONSTITUTION:The array of a flat composite electrode plate 1 having anodes 2 and cathodes 3 comprising plural electrode plates alternately arranged thereto, a chamber frame gasket and a cation exchange membrane 16 is used as a recurring unit to constitute an electrolytic tank as well as anodes 2 and cathodes 3 of adjacent composite electrode plates 1 are opposed so that the cation exchange membrane 16 is interposed therebetween and current is passed in the order of A B A B. An anode liquid is supplied to an anode chamber 5 from a supply passage 11 through a communication passage 13 and an anode product prepared therein by electrolysis is discharged to a passage 7 through a communication part 9 to be taken out to the outside. On the other hand, a cathode liquid is supplied to a cathode chamber 6 from a supply passage 12 through a communication part 14 and a cathod product produced therein as the result of electrolysis is discharged to a passage 8 through a communication part 10 to be taken out to the outside.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a bipolar electrolytic cell, and particularly to a single-plate filter press type bipolar electrolytic cell.

A conventionally known bipolar electrolytic cell is one in which a partition is disposed between an anode and a cathode, the anode and the cathode are electrically connected to the partition, and a current is passed from the cathode to the anode through the partition.

However, in this conventional multi-electrode electrolytic cell, one side of the partition wall is in contact with the anolyte and the other side is in contact with the catholyte. Under certain conditions, the laminated structure with corrosion-resistant metal had to be used. Between these two sleeves of metal~,
Not only is it quite difficult to ensure air-gutter oil conductivity, but in the case of alkaline electrolysis, there are problems with hydrogen embrittlement of the metal due to hydrogen gas generated in the cathode chamber, and hydrogen in the metal permeates and causes damage to the two glazes in the partition wall. reaches the joint surface of the metal, and this hydrogen gas evaporates,
Problems such as peeling of the joint surfaces have arisen, and various proposals have been made regarding the structure of the partition walls.

However, these improvement methods only unnecessarily complicate the structure of the partition wall, and in many cases only increase the processing cost without achieving much effective improvement.

In response to this, the inventors made a major change in their thinking,
We conducted various studies on bipolar electrolytic cells that do not use partition walls at all, and came to the conclusion that it is possible to create bipolar electrolytic cells without using partitions by using a different method of current flow than before. , the present invention has been achieved, and the present invention provides: (a) a substantially flat composite electrode plate of an anode and a cathode formed by joining one anode plate and one cathode plate; (a) an anode chamber; The openings forming the cathode chamber and the openings forming the cathode chamber are arranged horizontally alternately, and there are two small openings above and below each opening.
The chamber frame gasket (c) cation exchange membrane has a chamber frame gasket (c) cation exchange membrane, and each opening has a communication section that communicates with one upper and lower aperture. The arrangement of membranes is one repeating unit, or the arrangement of composite electrode plate/chamber frame gasket/composite electrode plate/cation exchange membrane is one repeating unit, and several of these repeating units are arranged between two end plates. It is an electrolytic cell that is tightened with scissors X7, and the composite electrode plates are arranged in the repeating unit so that the polarity of the gold electrode plates in the repeating unit adjacent to each other with the cation exchange membrane in between is opposite. The gist of this invention is a bipolar electrolytic cell characterized by being arranged in large numbers.

Hereinafter, the present invention will be explained based on the drawings.

FIG. 1 is a partial perspective view of an electrolyte of the present invention having a composite V-electrode plate/chamber frame gasket/cation exchange membrane as a repeating unit.

First, the composite electrode plate will be explained.

The composite electrode plate 1 is a flat anode/cathode composite in which an anode and a cathode made of a known perforated plate electrode are bonded so as to maintain substantially flatness. This bonding method is not particularly limited, but one side of a rectangular thin porous anode and a similar porous cathode are slightly overlapped with a long thin piece of metal such as thin copper, and then heated and pressed to diffuse. A preferred method is to use a bonding method.

When this method is used, the joined part is slightly stepped, but since the electrode plate and metal piece are very thin, the composite electrode plate obtained by joining maintains substantially flatness, so it is not practical. There is no problem.

If it is desired to avoid even this slight step, the anode plate and the cathode plate may be butted against each other and the portions may be joined by brazing or the like.

The shape of the anode and cathode plates may be porous like ordinary expanded metal, but they may also be shaped like louvers obtained by making vertical slits in the electrode plate and twisting them, or For reasons described later, it is more preferable to press and extrude every other strip to be formed on one side of the electrode surface, or to alternately extrude every other strip on both sides of the electrode surface.

The chamber frame gasket 4 can be made of elastic rubber such as BDPM or synthetic resin such as PVC. The chamber frame gasket 4 is provided with a plurality of openings in the horizontal direction corresponding to the sizes of the anode portion and the cathode portion of the composite electrode plate, and these openings sequentially form an anode chamber 5 and a cathode chamber 6. Two openings are provided at the top and bottom of the opening of the chamber frame gasket, respectively. The opening provided in the upper part is divided into an anode product passage 7 and a cathode product passage 8, and the anode product passage 7 communicates with the anode chamber 5 through a communication section 9, and the cathode product passage 7 is divided into an anode product passage 7 and a cathode product passage 8. 8 is the cathode chamber 6 and the communication part 1
Connected by 0.

The opening provided in the lower part is divided into an anolyte supply passage 11 and a catholyte supply passage 12, the anolyte supply passage 11 communicates with the anode chamber 5 through a communication section 13, and the catholyte supply passage 12 communicates with the catholyte chamber 6. and communicating part 1 (communicated by).

Further, it is preferable that the chamber frame gasket is provided with a notch 15 having a size that covers a pair of adjacent anode chambers and a cathode chamber, and corresponding to the size and thickness of the composite electrode plate. When placing the composite electrode plate in contact with the chamber frame gasket,
By fitting the composite electrode plate into the above-mentioned chamber frame/notch, a liquid-tight effect can be obtained due to the elasticity of the rubber of the chamber frame.
This is preferable because there is no need to separately arrange a backing, and the composite electrode plate itself does not need to have openings for passing the electrolytic solution and electrolyzed products.

In this way, when a notch is provided in the chamber frame, the notch containing a pair of anode and cathode chambers and the adjacent pair of notches containing anode and cathode chambers are continuous and are not separated. It is necessary that the

Further, the communicating portions 9, 10, 13, 14 communicating with the electrode chamber may be holes punched in the chamber frame, or grooves provided in the chamber frame surface.

The cation exchange membrane 16 used in the present invention is preferably a perfluoro or carbon membrane containing one or more of carcinic acid groups, sulfonic acid groups, phosphonic acid groups, etc. as ion exchange groups. Examples of such cation exchange membranes include those disclosed in JP-A-52-48598 and JP-A-53.
Those disclosed in Japanese Patent No.-22194 are preferably used.

Additionally, a gas and liquid permeable porous layer made of particles with no electrode activity, such as titanium oxide or silicon carbide, on the surface of the cation exchange membrane described above may also be used to lower the electrolytic voltage. Used as preferred.

Next, a method for assembling the t1 tank disassembly of the present invention using the above-described composite electrode plate, chamber frame gasket, and cation exchange membrane will be explained.

The power supply part and the current extraction part for the electrolytic cell in which the composite electrode body is fitted into the notch of the chamber frame gasket are provided by attaching conductive members 17 and 18 to one anode plate and one cathode plate, respectively, and connecting these electrodes to the anode. When arranging the above electrodes, which are fitted into the notches of the chamber frame gasket corresponding to the size of the plate and the cathode plate, the polarity of the electrodes facing each other across the cation exchange membrane should be opposite.

Next, a cation exchange membrane is applied to the opposite surface of the chamber frame gasket where the electrode is located, to obtain the repeating unit A or B shown in FIG. Then, the repeating unit is A as shown in Figure 1.
BAB---arranged in one order, with end plates provided at both ends,
When assembled in a filter press type, the electrolytic cell of the present invention is obtained. Then, by connecting the conductive members 17 and 18 provided in every other repeating unit to the anode busbar and the cathode busbar, the current is first passed from the anode plate of unit B through the cation exchange membrane to the opposite side. The current flows from the anode plate of this composite electrode plate through the cation exchange membrane to the cathode plate of the composite electrode plate of unit B placed opposite it. In this way, the current flows perpendicularly to the direction in which the filter press type battery case is tightened, and in the horizontal direction in units of A-1-B-
It flows like A-B-1, and flows to the bus bar on the cathode side via the conductive member 18 of the cathode provided on the side opposite to the power supply side.

A known method may be used for discharging the catholyte and flowing the catholyte. To explain it with reference to FIG.
The electrolyzed product is discharged into the anode product passage through the communication portion 9, and taken out from the electrolytic cell through this passage. On the other hand, the catholyte is supplied from the catholyte supply passage 12 to the cathode chamber via the communication part 14, and the catholyte product produced as a result of electrolysis there passes through the communication part 10 to the cathode product passage 8.
from which it is discharged to the outside of the battery case.

Next, the structure of an electrode suitable for the electrolytic cell of the present invention will be explained.

FIG. 2 is a partial perspective view showing the structure of an electrode that can be suitably used in the electrolytic cell of FIG. 1.

FIG. 3 is a perspective view showing another preferred electrode structure.

In the case of Figure 2, a narrow slit is made in the flat electrode,
It is easily manufactured by pressing and extruding every other strip on one side. In this case, assuming that the extrusion height is equivalent to the remaining thickness of the notch in the chamber frame gasket, it is better to make it slightly smaller than that.

The electrode thus obtained consists of the extruded strip portion 19
and flat strip portions 20 are arranged alternately.

When this electrode is used in the electrolytic cell shown in FIG. 1, it is arranged so that the extruded strip portion 19 is placed in the electrode chamber.

The electrode shown in Figure 3 can be easily manufactured by making narrow slits in the same way as the electrode shown in Figure 2, and pressing and extruding the strips alternately on the opposite side of the electrode surface. .

The electrode thus obtained is a lantern-shaped electrode consisting of a strip portion 21 extruded on one side and a strip portion 22 extruded on the opposite side.

An electrolytic cell using this electrode is suitably used in a battery cell which is slightly modified from the electrolytic cell shown in FIG. 1 and has chamber frame gaskets arranged on both sides of the cation exchange membrane.

As can be seen from the above explanation, when the electrodes shown in Figures 2 and 3 are used, the electrodes come close to or come into contact with the cation exchange membrane, and as a result, the distance between the anode and cathode decreases, and the electrolytic voltage This has the advantage of being smaller.

Thus, the electrolytic cell of the present invention is an excellent bipolar electrolytic cell that is easy to manufacture and can be used for various electrolysis and synthesis reactions, but is particularly suitable for aqueous electrolysis of alkali chlorides and water electrolysis. It is.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a partial perspective view showing one example of the electrolytic cell of the present invention. FIG. 2 is a partial perspective view showing one example of an electrode used in the electrolytic cell of the present invention. FIG. 3 is a partial perspective view showing one example of an electrode used in the electrolytic cell of the present invention. For tl.

Claims (1)

[Claims] (a) A substantially flat composite electrode plate of an anode and a cathode formed by joining one anode plate and one cathode plate (b) An opening forming an anode chamber and a cathode chamber The openings forming the
The chamber frame gasket (C) cation exchange membrane has a chamber frame gasket (C) cation exchange membrane, each opening having a communication section that communicates with the upper and lower apertures, and the composite electrode plate / chamber frame gasket / cation exchange The arrangement of membranes is considered as one repeating unit, but the arrangement of composite electrode plate/chamber frame gasket/composite electrode plate/cation exchange membrane is considered as one repeating unit, and a plurality of these repeating units are placed between two end plates. It is an electrolytic cell that is clamped with a cation exchange membrane in between, and a large number of composite electrode plates are arranged in a repeating unit so that the polarities of the composite electrode plates in the repeating units that are placed adjacent to each other with a cation exchange membrane in between are opposite polarities. A bipolar electrolytic cell that is characterized by the following characteristics: