In the 21st century, China’s consumption structure of hydrazine hydrate as: pesticides accounted for 40% of the total share, blowing agents accounted for 30% of water treatment chemicals accounted for 14% accounted for a percentage of the other the thirteen. At present, China is far lower than the foreign hydrazine hydrate production capacity; still can not meet domestic market needs. Therefore, the development of domestic production capacity of hydrazine hydrate and advanced production technology has enormous economic and far-reaching social benefits.
Currently, Japan, South Korea, the United States and France have a larger hydrazine hydrate production capacity, while demand in these countries is limited; it has a strong export capacity. The steady growths in demand of hydrazine hydrate, and gradually become an important global consumer market. Japan and South Korea hydrazine hydrate are mainly exported to China, the United States and France are also optimistic about China's market.
The current production technology of hydrazine hydrate
Now the production of hydrazine hydrate in China is mainly used in the urea method.
The main is a bit of urea is low investment. The operation is simple, device does not need too much, and now the domestic hydrazine hydrate is small-scale production, is one of the most economical production methods. The urea method in our country has been a long time now, almost all companies are using this method, the synthetic yield higher than raschig process. However, due to the use of high raw material prices compared to other methods, it is in mass production, it can not compete with other methods; this method has been largely foreign to be eliminated. Although many domestic enterprises have done a lot of urea method of technological innovation , but taking into account many of the shortcomings of its existence , so many domestic producers is both the production of urea and production of hydrazine hydrate . So now the Chinese urea method is very suitable for the current situation.
About low cost of raw materials Raschig process, in the production of large scale, the total cost than Urea is low, but the Act pollution, high energy consumption and equipment investment, at home and abroad have been very few manufacturers to adopt the methods of production.
Hydrogen peroxide method with Raschig process and ketone of method of economical comparison mainly depends on the relative price of chlorine, sodium hydroxide. The yield can reach 75%, if there is a cheap source of hydrogen peroxide, which is very attractive. But domestic technology is not mature and widely used.
Ketazine method has significant advantages, as ketazine production to avoid the decomposition of hydrazine, yields were close to the theoretical value, and the energy consumption is about Rasi law 1/3. In one method, azine, hydrazine as a ketazine and water to form a low boiling azeotrope is removed from the top, leaving the rest of the water and salt in the tower kettle.
Rasi law hydrazine with water to form high-boiling azeotrope exists in the bottom, a lot of water to be evaporated . And in order to prevent the precipitation of salt tower reactor, but also need to pre- evaporation desalination, so energy consumption. In the energy crisis, prices circumstances, ketazine of energy saving advantage is particularly important. In addition, investments in equipment ketazine France lower than Raschig process. The disadvantage ketazine product to processor and consume acetone. But in general, ketazine method is superior to Raschig process, developed rapidly in recent years.
Now, with the continuous development of the country, for the future of the chemical industry, hydrazine hydrate products demand will continue to increase, domestic technology in the future will adopt efficient ketazine France. Urea society will eventually come out of the stage.
31 juillet 2014