JPS63100190A - Electrolytic device for generating gas - Google Patents

Abstract

PURPOSE:To eliminate the interruption of electrolysis and to prevent the damage of an electrode by directly connecting an anolyte container to an upper anode side, and immersing the anode in the anolyte in the title electrolytic device for generating gas. CONSTITUTION:An upper main anode 2, an upper porous collecting electrode 3, a solid polymeric electrolyte membrane 4, a lower porous collecting electrode 5, and a lower main cathode 6 are successively laminated on one another, and clamped by a bolt 7 coated with an insulating sleeve through an O ring 22, and a glass bell jar 12 is fixed to the upper main anode 2 with a stud bolt 13 to form the electrolytic device 1 for generating gas. The anolyte is supplied from an inlet 11 and circulated through an intake hole 9, an outlet hole 8, and a gas-lift pipe 17, and the upper porous collecting electrode 3 is always kept under the anolyte surface. The ozone-contg. oxygen generated by this structure flows in the inclined groove 19 of the upper anode 2 toward the center, reaches the outlet hole 8, rises in the gas-lift pipe 17, and is taken out to the outside from an outlet 10.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an on-site type gas generation electrolyzer for generating gases such as oxygen, ozone, chlorine, etc. at an anode.

(Prior Art) A method of generating oxygen or ozone-containing oxygen by water electrolysis and a method of generating chlorine by hydrochloric acid electrolysis belong to known techniques. Many conventional electrolyzers for gas generation follow commonly used systems. For example, in the case of ozone-containing oxygen generation by water electrolysis, as shown in Figure 4, European Patent Publication No. 82200493 describes Although disclosed, it has a complicated configuration, such as storing electrolyte and forcibly feeding the electrolyte to a separately installed electrolytic tank using a pump.It is compact, labor-saving, and highly safe. Moreover, an inexpensive device is desired. An electrolytic device for gas generation that meets such requirements is difficult to achieve with conventional electrolytic cell structures, and has not been known to date.

(Problems to be Solved by the Invention) On-site gas generators have problems with the transportation and storage of oxygen, chlorine, etc. using conventional gas cylinders (such as transportation to remote locations, and High Pressure Gas Control Law). In order to become an effective means to replace the storage problems under the Poisonous Substances Control Law), it must be compact, easy to operate and maintain, do not require human labor, be safe, and be economical. Must be. For this purpose, a device with a forced circulation mechanism using a pump such as the above-mentioned conventional technology is not necessarily suitable because the structure is complicated, while a natural circulation type device prevents liquid from partially running out during operation. The current density cannot be increased because of the risk of causing a nuisance, which inevitably results in a large device and poses a safety problem. In order to solve these problems, the inventors devised an electrolytic cell structure that is completely different from conventional industrial electrolysis systems.

(Means for Solving the Problems) In order to produce a compact, ie, high current density electrolytic cell, it is preferable that the current density distribution on the electrode surface be uniform. Furthermore, it is necessary to always maintain a constant supply of anolyte to the electrode reaction surface so as not to create a depleted portion. If a depleted portion occurs, the electrical resistance will increase and the electrodes will be damaged due to heat generation, causing an accident.

A preferred configuration of a high current density electrolytic cell is to assemble a solid polymer electrolyte membrane and a porous collector electrode having many contact points for supplying power to the membrane as a set, which are tightened from both sides with one anode and one cathode.

The present invention is designed to ensure smooth extraction of generated gas and constant contact with the anolyte without interruption in the supply of anolyte to the electrode reaction surface. In an electrolytic device for gas generation formed by laminating a collector electrode, a solid polymer electrolyte membrane, a lower porous collector electrode, and a lower main cathode, an anode liquid reservoir is directly connected to the upper electrode side, and the anode is connected to the anode. Electrolyzer for gas generation kept below the liquid level,
An electrolytic device for gas generation that has a gas lift pipe on the upper main anode and an anolyte circulation mechanism with multiple liquid supply holes at separate locations, and a groove is machined on the electrolytic chamber side, with the groove depth centered around the The gist of the present invention is an electrolytic device for gas generation, which is equipped with a generated gas collecting means using a main anode having a conical slope toward the bottom.

(Operation and Effect) As described above, the electrolytic device for gas generation according to the present invention has an upper main anode, an upper porous collector electrode in contact with the upper main anode, a solid polymer electrolyte membrane, a lower porous collector electrode, and a lower main cathode that are laminated. Moreover, since the electrolyte reservoir is directly connected to the upper electrode side and the anode is positioned below the electrolyte surface, the anolyte is always present on the anode side of the electrode, and the electrolysis is not interrupted. In addition, the anolyte circulation mechanism using a gas lift tube installed in the anolyte prevents damage to the electrode due to depletion of the anolyte, and the anolyte is well circulated because the rising gas generated serves as a driving source. , the anolyte is reliably supplied to the electrode, there is no need for a pump to forcefully feed the anolyte as in the past, there is no failure, the device is compact, and it has a high current density, e.g. 60A/drn” to 150A/di.
It becomes possible to drive. Incidentally, in the conventional natural circulation type, the limit was 30 to 60 A/drrl'.

Furthermore, since the main anode is provided with a generated gas collection means by an inclined groove on the electrolytic chamber side, the gas collects upward along the inclination and does not stay on the electrode surface, which helps to improve the electrolytic efficiency.

The structure described above eliminates systems such as electrolyte storage tank, liquid feeder, large electrolytic tank, and gas-liquid separator that are found in conventional electrolysis methods, making it possible to put into practical use an extremely simple device.As a result, it is compact and compact. This has the effect of simplifying the operation and maintenance equipment.

(Practical Example) As an example of the present invention, an electrolytic device for generating ozone-containing oxygen by electrolyzing water will be described below. 1 and 2, an electrolytic device 1 for gas generation includes an upper main anode 2, an upper porous collector electrode 3 in contact therewith, a solid polymer electrolyte membrane 4, a lower porous collector electrode 5, and a lower main cathode 6. are laminated and tightened with a bolt 7 covered with an insulating sleeve via an O-ring 22.

For the upper main anode 2, titanium, tantalum, niobium, or the like is normally used as a metal that can withstand oxidizing gas on the anode side. The material of the upper porous collector electrode 3 may be a porous body of the above-mentioned metal produced by machining, electrolytic processing, elution method, or sintering method, or a platinum group metal, oxide, or lead dioxide may be added to the surface. Those coated with catalytic metals or oxides such as catalytic metals are used.

The lower main cathode 6 is made of titanium, stainless steel (if the anolyte is other than hydrochloric acid), or carbon. As the material for the lower porous collector electrode 5, a porous carbon plate that is resistant to corrosion by generated hydrogen and entrained water or entrained electrolyte is often used, and this porous carbon plate is mainly produced by a sintering method.

A solid polymer electrolyte membrane is used as the diaphragm that separates the cathode and anode chambers. However, in practice, a fluorine-based ion exchange membrane is used which has sufficient resistance to ozone-containing oxygen generated at the anode. Representative products of this type of membrane include DuPont's NAF
There is an ION membrane. This ion-exchange membrane can be used as a raw membrane by pressing negative and positive electrodes, or by preparing a membrane-electrode assembly in which a catalyst electrode layer is bonded to the membrane surface in advance, and pressing porous collector electrodes onto this from both sides. use.

The upper main anode 2 has an anolyte outlet hole 8 in the center and a plurality of anolyte inlet holes 9 around the periphery, such as an anolyte reservoir with an upper outlet 10 and an anolyte port 11 on the side. It is covered with a container, for example a glass Pel jar 12, which is fixed to the upper main anode 2 with studs 13, so that the anolyte remains at a water level 14, so that the upper porous collector electrode 3 is always below the liquid level. The supply of anolyte to the upper porous collector electrode 3 takes place smoothly, and this porous collector electrode 3 supplies electrical power and diffuses the generated ozone-containing oxygen. Moreover, inside, a base 15 communicates with the anolyte outlet hole 8, and an upper end 16 has a glass Pel jar 12.
A gas lift tube 17 opening into the interior is provided, and the anolyte circulation mechanism 18 is formed by the anolyte inlet hole 9, the upper porous collector electrode 3, the electrolyte outlet hole 8, and the gas lift tube 17.
The anolyte introduced into the glass Pel jar 12 can be circulated through the gas lift tube 17 by raising the generated ozone-containing oxygen without being forced by a pump as in the conventional case. Prevents stagnation on the three surfaces of the porous collector electrode. Although the illustrated anolyte circulation mechanism 18 has the gas lift pipe 17 in the center of the glass pelger 12 and the intake port 9 around the periphery, it is of course possible to adopt the opposite arrangement.

On the lower surface of the upper main anode 2, inclined grooves 19 with deep grooves in the center are concentrically provided, and each groove 19 is connected to a generated ozone-containing oxygen collection means 21 through a communication groove 20 in the center direction, as shown in FIG. is formed. Therefore, the ozone-containing oxygen generated in the upper porous collector electrode 3 flows toward the center through the inclined groove 19, reaches the anolyte outlet hole 8, ascends the gas lift tube 17 together with the anolyte, and the liquid circulates, and the ozone-containing oxygen is taken out from the outlet 10.

The above example describes the generation of ozone-containing oxygen by water electrolysis, but it can of course also be widely used to generate chlorine by hydrochloric acid electrolysis, and electrolysis for generating other gases such as bromine. Fluorinated ion exchange membranes with sufficient resistance are recommended.

In this way, in the present invention, the anode side is constantly immersed in the anolyte to prevent damage to the electrode due to water running out, and is highly reliable.
It improves electrolysis efficiency by promoting the separation and collection of generated gases such as bromine from the electrode, and the anolyte circulation is improved by utilizing the rising force of the generated gas instead of using a forced device such as a pump. The anolyte circulation mechanism uses a gas lift tube for circulation, which eliminates malfunctions, saves energy, and eliminates the installation space of the pump, which has remarkable effects.

Experimental Example 1 An experiment was conducted to produce oxygen by water electrolysis using the electrolyzer according to the present invention.

Membrane-electrode assembly Nafion 117 membrane with platinum-iridium alloy bonded on both sides (DuPont product) Anode side collector electrode Platinum-plated titanium material cathode side collector electrode
Porous carbon material electrode effective area 50℃ Temperature 50-60℃ Anode liquid Water current 50A Current density 10QA/d+' Voltage 1.8 Volt Oxygen generation W 9.9Q/hr Current efficiency 99% Experimental example 2 Invention An experiment was conducted to produce ozone by water electrolysis using an electrolyzer.

Membrane-electrode assembly Nafion 117 membrane anode side collector electrode with platinum plating only on the cathode side Titanium material cathode side collector electrode plated with lead dioxide Porous carbon material electrode effective area 50 cIf Temperature 30-40℃ Anode liquid Water current 50A Current Density: 100 A/da' Voltage: 3.2 Volt Ozone generation amount: 1.7 g/hr Current efficiency: 11.4% Experimental Example 3 An experiment was conducted to produce chlorine by chlorine electrolysis using the electrolyzer according to the present invention.

Membrane-electrode assembly Nafion 117 membrane anode collector electrode with platinum-iridium alloy bonded on both sides Titanium cathode collector electrode coated with iridium oxide Porous carbon material Temperature 30°C Anolyte 7n-HCffi electrode
Current 30A Current density 80A/da' Voltage 1.8 Volt Chlorine generation m 37.6g/hr Current efficiency 95%

[Brief explanation of the drawing]

Fig. 1 is a sectional view of one embodiment of the present invention, Fig. 2 is an enlarged sectional view of the main part, Fig. 3 is a sectional view taken along the lines ■ and ■ in Fig. 1, and Fig. 4 is a flowchart of the conventional example. It is a sheet. l... Generation electrolytic device 2... Upper main anode 3...
- Upper porous collector electrode 4... Solid polymer electrolyte membrane 5... Lower porous collector electrode 6... Lower main cathode 7...
- Bolt - Anolyte outlet hole 9... Anolyte intake hole lO... Outlet 11... Electrolyte population 12... Glass Pel jar 13... Studded bolt 14... Water Position 15...Base
16...Top end 17...Gas lift pipe
18... Electrolyte circulation mechanism 19... Inclined groove 2
0...Communication groove 21...Contains generated ozone 22...
・O-ring oxygen collecting means

Claims (3)

[Claims] (1) an upper main anode and an upper porous collector electrode in contact with it;
In an electrolytic device for gas generation formed by laminating a solid polymer electrolyte membrane, a lower porous collector electrode, and a lower main cathode, an anode liquid reservoir is directly connected to the upper electrode side, and this anode is immersed in the anolyte liquid. An electrolytic device for gas generation characterized by immersion. (2) an upper main anode and an upper porous collector electrode in contact therewith;
In an electrolytic device for gas generation formed by laminating a solid polymer electrolyte membrane, a lower porous collector electrode, and a lower main cathode, an anode reservoir is directly connected to the upper electrode side, and a gas lift tube is connected to the upper main anode. An electrolytic device for gas generation having an anolyte circulation mechanism with a plurality of liquid supply holes at separate locations. (3) an upper main anode and an upper porous collector electrode in contact therewith;
In an electrolytic device for gas generation formed by laminating a solid polymer electrolyte membrane, a lower porous collector electrode, and a lower main cathode, a groove is machined on the electrolytic chamber side of the upper main anode, and the depth of the groove is adjusted to the center. An electrolytic device for gas generation equipped with a generated gas collecting means having a conical slope toward.