JP3432136B2 - Ozone and hydrogen generation method and generator - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention uses, for example, a perfluorocarbon-based cation-exchange membrane having a porous anode material and a cathode material in close contact on both sides thereof as a solid electrolyte, and supplies pure water to the anode side. The present invention relates to an electrolytic gas generator for producing ozone gas and oxygen gas from the anode side and hydrogen gas from the cathode side by performing electrolysis, and more specifically, the gas generator is always operated so that the pressure on the anode side is the pressure on the cathode side. The present invention relates to a simple, high-purity gas generator in which the concentration of hydrogen gas in ozone oxygen gas is extremely low by automatically controlling it so as to be more appropriately increased.

[0002]

BACKGROUND OF THE INVENTION The idea of generating ozone gas by electrolyzing water is old and has been practiced for more than 100 years. Although it was a solution electrolysis method that electrolyzes a liquid containing anion of high electronegativity to generate ozone in the old days, in recent years, with the development of solid polymer electrolytes, water electrolysis using solid polymer electrolytes has been performed. Ozone generator was manufactured by and is now on the market.

A so-called zero gap type water electrolysis in which a perfluorocarbon sulfonic acid type cation exchange membrane is used as a solid electrolyte and an anode and a cathode are adhered to both sides of the solid electrolyte is simple in structure and easy to handle, and corrosive to ozone gas. Since there is nothing but it, it has come to occupy most of the water electrolysis method ozone generation in recent years.

The concentration of ozone gas is around 20%, and the other is oxygen gas containing saturated steam and is a mixed gas of ozone and oxygen containing almost no impurities.

Therefore, the use of ozone has been widespread in the field of sterilization and recently in the field of wet cleaning of semiconductors. Compared to the silent discharge method, which uses oxygen as a raw material and generates ozone by applying high frequency and high voltage, it has the drawback of slightly higher power consumption, but its high ozone gas concentration results in high solubility in ultrapure water and high purity. There was an advantage that high-concentration ozone-added ultrapure water could be easily manufactured.

However, as the density of the semiconductor becomes higher, the miniaturization is required, and the accuracy of cleaning has been particularly required in recent years.

In the ozone generation by electrolysis, the hydrogen gas generated on the cathode side so far diffuses and mixes with the ozone gas on the anode side to generate hydrogen contamination of 100 to 800 ppm, which is a problem in cleaning by ozone. Has occurred. Although there are other impurities, it is required to extremely reduce the hydrogen gas concentration in ozone gas.

[0008]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned problems of the prior art, minimizes the contamination of ozone gas, particularly the concentration of hydrogen gas, and provides safe and highly pure ozone gas and hydrogen gas. It is an object of the present invention to provide an electrolytic ozone generating device, a hydrogen generating device and a generating method.

[0009]

According to the method for generating ozone and hydrogen of the present invention, a porous anode material and a cathode material are disposed on both sides of the ozone, and a solid electrolyte is disposed therebetween, and pure water is disposed on the anode side. In an electrolytic gas generator that produces ozone gas and oxygen gas from the anode side by supplying and electrolyze, and hydrogen gas from the cathode side, the pressure on the anode side is always greater than the pressure on the cathode side, and the difference is 2.0 kg /
As becomes cm ² in than, the pressure on the anode side, and or, and controlling the pressure on the cathode side.

In the ozone and hydrogen generator of the present invention, a cation exchange membrane having a porous anode material and a cathode material in close contact with each other is used as a solid electrolyte, and pure water is supplied to the anode side. In an electrolytic gas generator that produces ozone gas and oxygen gas from the anode side and hydrogen gas from the cathode side by electrolysis, the pressure on the anode side is always greater than the pressure on the cathode side, and the difference is 2.0 kg / as becomes cm ² in than, the pressure on the anode side, and or, characterized in that a means for controlling the pressure on the cathode side.

The present invention will be described in detail below.

For example, when a perfluorocarbon type cation exchange membrane is used as a solid electrolyte and an anode material and a cathode material are closely arranged on both sides thereof, and water electrolysis is performed, hydrogen gas generated at the cathode is diffused, and usually 100 to 100%. It was the current situation that 800 ppm of hydrogen gas was mixed in ozone gas.

In the present invention, for example, a perfluorocarbon type cation exchange membrane is used as a solid electrolyte, and an anode material and a cathode material are closely arranged on both sides of the solid electrolyte, and water electrolysis is performed to carry out ozone gas and oxygen gas from the anode and hydrogen from the cathode. at device for generating a gas, always the pressure of the anode side was larger than the pressure of the cathode side and, as the difference becomes 2.0 kg / cm ² in the following, by controlling the pressure of the anode and cathode sides As a result, it has become possible to extremely reduce the hydrogen concentration in the ozone gas and to keep the oxygen concentration in the hydrogen gas within the limit.

The perfluorocarbon sulfonic acid type cation exchange membrane has very fine holes, and since the thickness is as thin as about 100 μm, oxygen gas hardly diffuses to the hydrogen gas side, but hydrogen gas Has a very small molecule and diffuses to the ozone gas side. Platinum or carbon is placed in the anode chamber, and the diffused hydrogen gas is treated with ambient ozone,
We tried to reduce hydrogen gas by reacting it with oxygen gas and changing it to water, but platinum had no effect at all, and with carbon, it reacted violently on carbon and the carbon itself burned out with a flame and could not be used. It could not be reduced. Next, the pressure on the anode side was made higher than the pressure on the cathode side, and the hydrogen concentration in the ozone gas was confirmed. This made it possible to reduce the hydrogen gas concentration in ozone gas.

Next, detailed conditions for the gas generator according to the present invention will be described.

Regarding the hydrogen concentration in the ozone gas in the gas generator, it is sufficient to increase the differential pressure between the anode chamber and the cathode chamber as long as the hydrogen concentration is lowered as described above. The pressure difference is limited due to the structural limitation of the generator. Since the cathode of electrolytic ozone is densely configured, it is possible to suppress the ion exchange membrane, which is a solid electrolyte, without damaging it, and a large differential pressure between the anode and the cathode can be obtained, but the ion exchange membrane is an O It is held down by a ring or the like, and there is a risk that it will break near the seal due to the application of differential pressure. Therefore, the differential pressure is 2.0
kg / cm ² is in the following, it is desirable at 1.5 kg / cm ² in the following.

The hydrogen gas concentration in the ozone gas, which was 400 ppm when the pressure difference was absent, changed the pressure difference to 1.5 kg / cm ^2.
When it was g, it was 1 ppm, which was a value that could be sufficiently used for cleaning semiconductors. On the other hand, the oxygen gas concentration in hydrogen gas was 3 ppm when the pressure difference was absent, but increased to 30 ppm, but there was no problem in using it.

Although it is possible to manually control the pressure of ozone gas and the pressure of hydrogen gas to be constant by operating a valve or an orifice, the pressure fluctuates depending on the amount of generated gas, and therefore it cannot be performed manually. There have been problems that it takes a lot of time and that water or the like accumulates in a place where the valve or the orifice is narrowed to change the pressure. To solve such problems, the orifice is opened when the amount of gas is increased, and when it is decreased, the orifice is narrowed to automatically keep the gas pressure constant. It is desirable to generate highly pure ozone gas and hydrogen gas.

Ozone water is not always supplied in the wet cleaning of semiconductors, and the supply and stop of ozone water are periodically repeated along with the operation of tact. In ozone generation by water electrolysis, repeated operation and stop repeatedly greatly affect the life of ozone generation.Therefore, in such frequent operation stop, ozone generation is not stopped, and when ozone water is not supplied, the ozone water is drained. Thrown in. In order to avoid such waste and to keep the ozone gas concentration, which has the greatest impact on ozone water production, at a high level, a device that continuously operates a gas generator and adsorbs ozone gas to a conduit led from the gas generator to condense it. By installing and periodically repeating adsorption and desorption,
It becomes possible to supply highly concentrated and economical ozone water.

As with the ozone gas, hydrogen gas is continuously generated and hydrogen gas is supplied only when necessary to clean semiconductors, thereby providing an economically necessary minimum device. I can do things.

Generally, silica gel is used for the concentration of ozone gas, and so-called hydrogen storage alloy is used for hydrogen gas, which has a mechanism of storing by cooling and desorbing by heating.

As described above, it is possible to eliminate the conventional hydrogen gas contamination by applying pressure to at least ozone gas, but it is dangerous because pressure is applied to the gas even though it is automatically controlled. Sex increases.

Therefore, a mechanism for detecting pressure on the ozone gas side and, if possible, on the hydrogen gas side is also provided, and when the set value is exceeded, gas generation is stopped and pure water supply is stopped.
It is desirable to have a mechanism that can release gas instantly.

Further, in order to avoid gas leakage from the seal part of the generating part and the connecting part of the pipe, and to avoid legal regulation of gas, the gas pressure is within 10 kg / cm ^2. As described above, it is desirable to have a mechanism capable of controlling the pressure to 7 kg / cm ² or less.

Next, an example of a device for generating ozone gas, oxygen gas and hydrogen gas by electrolysis according to the present invention will be described with reference to the accompanying drawings.

FIG. 1 is a flow chart of an electrolytic gas generator according to the present invention. Pure water 3 is supplied to an ozone gas / hydrogen gas generation unit 1, and a power source 2 is connected to the power source 2.
Gas is generated by the electric current from the.

The generated ozone and hydrogen gas are separated by the gas separation towers 4 and 5, and are introduced into the ozone gas conduit 11 and the hydrogen gas conduit 17, respectively. The pressure of ozone gas is adjusted by the automatic pressure adjusting mechanism 10.

Further, the pressure of the hydrogen gas is adjusted by the automatic pressure adjusting mechanism 16 like the ozone gas.

FIG. 2 is a flow chart of an electrolytic gas generator including a concentrating device according to the present invention.

Pure water 3 is supplied to the ozone gas / hydrogen gas generator 1, and a power source 2 is connected to the ozone gas / hydrogen gas generator 1. The current from the power source 2 generates gas. The generated ozone and hydrogen gas are separated by the gas separation towers 4 and 5, and are introduced into the ozone gas conduit 11 and the hydrogen gas conduit 17, respectively. The pressure of ozone gas is adjusted by the automatic pressure adjustment mechanism 10,
Cooling device 9 concentrated by the ozone gas concentrating device 8 and attached
High-concentration ozone gas is released by being heated at. Further, for safety, the pressure detector 7 detects the pressure, and the control unit 6 stops the gas generation when the pressure is abnormally high.

Further, the pressure of the hydrogen gas is adjusted by the automatic pressure adjusting mechanism 16 like the ozone gas, and the hydrogen storage device 1
Hydrogen gas is released by being stored at 4 and being heated by the attached cooling device 15. Further, for safety, the pressure detector 12 detects the pressure, and the control unit 13 stops the gas generation when the pressure is abnormally high.

FIG. 3 is a flow chart of a conventional electrolytic gas generator.

Pure water 3 is supplied to the ozone gas / hydrogen gas generator 1, and a power source 2 is connected to the ozone gas / hydrogen gas generator 1. The current from the power source 2 generates gas. The generated ozone and hydrogen gas are separated by the gas separation towers 4 and 5, and are introduced into the ozone gas conduit 11 and the hydrogen gas conduit 17, respectively.

[0034]

EXAMPLES Next, examples of the ozone hydrogen gas generator according to the present invention will be described, but the examples do not limit the present invention.

(Example 1) Using a perfluorocarbon sulfonic acid type cation exchange membrane as a solid electrolyte and a water electrolysis apparatus in which an anode and a cathode are arranged in close contact, gas contamination by pressure was confirmed.

When electrolysis was performed with the anode and cathode open to the atmosphere, the hydrogen concentration in the ozone gas was 340 ppm and the oxygen concentration in the hydrogen gas was 8 ppm. When the pressure on the anode side was increased while leaving the cathode side as it was, 1 kg / cm
² , the hydrogen concentration is 1.2ppm and the oxygen concentration is 20p.
It became pm.

Further, at 1.5 kg / cm ² , the hydrogen concentration becomes 0.8 ppm, and the oxygen concentration becomes 27 ppm.
At 0 kg / cm ² , the hydrogen concentration was 0.7 ppm and the oxygen concentration was 30 ppm, but at 2.5 kg / cm ² , the hydrogen concentration was 0.7 ppm and the oxygen concentration was 60 ppm.
And soared.

On the other hand, conversely, when the pressure on the cathode side was increased while leaving the anode side as it was, the hydrogen concentration was 800 ppm and the oxygen concentration was 8 ppm at 0.2 kg / cm ² .

Furthermore, when the ozone gas concentration on the anode side was also measured at the same time, it was 20% on both the anode side and the cathode side when exposed to the atmosphere. When pressure was applied to the anode side, it remained at 20% regardless of the pressure. However, when pressure was applied to the cathode side, it decreased to 10% at 0.2 kg / cm ² .

From the above, the value that can be used for cleaning semiconductors is 2.0 kg / maximum when pressure is applied to the anode side.
It is considered to be cm ² .

(Example 2) The ozone and hydrogen gas generator used in Example 1 was used, and an ozone concentrator was installed in the middle of the ozone gas conduit to confirm changes in ozone gas concentration during adsorption and desorption of ozone.

The ozone gas concentration when the ozone concentrator was not attached was constant at 20 wt%. However, when the generator was stopped, it decreased with time and became almost zero in 40 minutes. When the electrolysis was started again, the ozone gas concentration increased, but it took 10 minutes to reach 20 wt%.

On the other hand, the ozone gas concentration was measured when an ozone concentrator was attached and adsorption / desorption was performed. When the temperature is set to -35 degrees, ozone adsorption starts and the ozone gas concentration is 15
It became wt% and was constant for 10 minutes.

Next, when the temperature was set to 0 ° C., ozone desorption started, and the ozone gas concentration increased and became constant at 25 wt%.

The provision of the concentrator makes it possible to keep the fluctuation range of the ozone gas concentration constant without stopping the gas generator.

[0046]

According to the present invention, the concentration of hydrogen gas in ozone gas is reduced and the concentration of oxygen in hydrogen gas does not increase so much, so that it can be used for cleaning semiconductors.

Further, by automatically controlling the pressure, a safe and highly purified gas can be obtained.

Furthermore, by attaching a storage device to the gas conduit, the life of the ozone hydrogen gas generator is extended, and it becomes possible to easily produce high-concentration ozone water and hydrogen water.

[Brief description of drawings]

FIG. 1 is a flow chart of an ozone / hydrogen generator according to a first embodiment.

FIG. 2 is a flow chart of an ozone / hydrogen generator according to a second embodiment.

FIG. 3 is a flow chart of an ozone / hydrogen generator according to a conventional example.

[Explanation of symbols]

1 ozone gas, hydrogen gas generation part, 2 power supply, 3 pure water, 4 gas separation tower, 5 gas separation tower, 6 control part, 7
Pressure detector, 8 ozone gas concentrator, 9 cooling device, 10 automatic pressure adjusting mechanism, 11 ozone gas conduit,
12 pressure detector, 13 control unit, 14 hydrogen storage device, 15 cooling device, 16 automatic pressure adjusting mechanism, 17
Hydrogen gas conduit.

─────────────────────────────────────────────────── ─── Continuation of the front page (73) Patent holder 000004400 1-2-8 Shinsuna, Koto-ku, Tokyo Organo Co., Ltd. (72) Inventor Tadahiro Omi 1-17, 2 Yonegabukuro, Aoba-ku, Sendai-shi, Miyagi Prefecture 301 (72) Inventor Isamu Sawamoto No.6, 1-49, Kashima, Chuodai, Iwaki, Fukushima Prefecture Core Technology Co., Ltd. (72) Inventor, Yasuhiko Kasama 3-31, Meidori, Izumi-ku, Sendai-shi, Miyagi Fron Corporation In-Tech (72) Inventor Kenichi Mimori 3-31, Meidori, Izumi-ku, Sendai-shi, Miyagi FRONTEC Co., Ltd. (72) Inventor Takayuki Imaoka 1-4-9 Kawagishi, Toda City, Saitama Organo Research Institute In-house (72) Inventor Koji Yamanaka 1-9-9 Kawagishi, Toda City, Saitama Organo Research Institute (72) Inventor Taisetsu Shirai Tai Sendai City, Miyagi Prefecture Shiro-ku Yagiyamahonmachi 2-chome 2-11-305 (56) Reference JP-A-8-188895 (JP, A) JP-A-10-43777 (JP, A) JP-A-4-88182 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) C25B 1/00-15/08 C01B 13/10

Claims (11)

(57) [Claims] 1. A porous anode material on each side thereof,
And an electrolytic gas for producing ozone gas and oxygen gas from the anode side and hydrogen gas from the cathode side by arranging a cathode substance, arranging a solid electrolyte therebetween, and supplying pure water to the anode side for electrolysis. In the generator, the pressure on the anode side is always higher than the pressure on the cathode side, and the difference is 2.0 kg /
A method for generating ozone and hydrogen, characterized in that the pressure on the anode side and / or the pressure on the cathode side is controlled so that the pressure is within cm ² . 2. The solid electrolyte diffuses hydrogen gas
Cation exchange membrane with pores that make it difficult for oxygen gas to diffuse
The ozone and hydrogen generation according to claim 1, wherein
Raw method. 3. The solid electrolyte is a perfluorocarbon-based cation exchange membrane, or
2. The method for generating ozone and hydrogen according to 2 . 4. A porous anode material on each side thereof,
Also, a cation exchange membrane in which a cathode substance is closely arranged is used as a solid electrolyte, and ozone gas and oxygen gas are produced from the anode side and hydrogen gas is produced from the cathode side by supplying pure water to the anode side for electrolysis. In the electrolytic gas generator, the pressure on the anode side is always higher than the pressure on the cathode side, and the difference is 2.
Pressure on the anode side so that the pressure is within 0 kg / cm ² , and /
Alternatively, an ozone / hydrogen generator characterized in that a means for controlling the pressure on the cathode side is provided. 5. The solid electrolyte diffuses hydrogen gas.
Cation exchange membrane with pores that make it difficult for oxygen gas to diffuse
5. Ozone and hydrogen generation according to claim 4, wherein
Raw method. 6. The cation exchange membrane is a perfluorocarbon cation exchange membrane.
The ozone and hydrogen generator according to 4 or 5 . 7. A device for adsorbing and / or concentrating ozone gas is provided in the ozone gas conduit generated by electrolysis, and the concentration of ozone gas is controlled by operating a cooling and heating mechanism attached to the device. and / or, to claims 4, characterized in that by adding a mechanism for controlling the capacity
6. The ozone / hydrogen generator according to any one of 6 above. 8. A hydrogen gas is provided by adsorbing and / or concentrating hydrogen gas on the conduit of the hydrogen gas generated by electrolysis, and operating a cooling and heating mechanism attached to the device. concentration, and / or ozone according to any one of claims 4 to 7, characterized in that by adding a mechanism for controlling the volume, hydrogen generator. 9. An ozone gas side and / or a hydrogen gas side is provided with a mechanism for detecting pressure respectively, and a signal thereof is sent to a control mechanism to control a pressure controller and / or an electrolysis current so as to control within a set range. to ozone according to any one of claims 4 to 8, characterized in that the control in the above range, the hydrogen generating apparatus. 10. The pressure detecting device is provided with a mechanism for detecting the pressure, and a signal thereof is sent to a control mechanism, which has a function of instantaneously releasing gas when the pressure exceeds a preset range. Any one of items 4 to 9
The ozone and hydrogen generator described in the item. Wherein said solid electrolyte is any one of claims ozone claim 4 which <br/> stone 10, which is a perfluorocarbon cation exchange membrane, the hydrogen generating apparatus.