With the development of ozone preparation technology, there are many preparation methods of ozone. According to their generation methods, they mainly include electrochemistry, atomic radiation, photochemistry and corona discharge.
More than 80% of the ozone sources used in industrial production are gas corona discharge ozone generators. The air source of small ozone generators can be air source or oxygen source, while the air source of large ozone generators generally adopts oxygen source. Foreign ozone generators generally use oxygen source.
In terms of the domestic market, the use of oxygen source can save the operation cost of ozone more than air source, but there are on-site problems in the maintenance of liquid oxygen storage tank, so the method of on-site oxygen generator is also accepted in the market. At present, there are three main methods for ozone preparation:
As one of the oldest methods, electrochemical method is to produce ozone by electrolysis of oxygen-containing electrolyte. It has some advantages that other methods do not have, such as high ozone concentration and purity. At present, it is suitable for some small-scale ozone application scenarios.
Photochemical method separates oxygen through high-energy ultraviolet light in the light source to produce oxygen atoms, and polymerizes with another molecule of oxygen to produce ozone. Under the condition of low-pressure mercury UV lamp, the photochemical conversion efficiency is only less than 2%, and the economic value of industrial application is not high.
The advantage of this method is that the polymerized ozone has low sensitivity to environmental humidity and temperature, has good data repeatability, and the generation of ozone is linearly related to the power of the light source. Therefore, the specific output and concentration of ozone can be controlled by adjusting the power of the light source.
Corona discharge means that under the condition of high-voltage alternating electric field, oxygen produces corona discharge, its high-energy free electrons dissociate oxygen molecules, and then polymerize into new ozone molecules through atomic collision reaction.
Compared with electrochemical method and photochemical method, corona discharge method has greater market application value. At present, the large and medium-sized ozone generators on sale are basically corona discharge method, and the corona discharge cost is gradually reduced through continuous technical iteration.