The normal pressure method for melamine production has the advantages of short process, less equipment investment and low energy consumption, but the yield and operation are not stable. Therefore, more attention should be paid to energy saving and consumption reduction in operation.
The main 5 factors affecting the yield of melamine in normal pressure method are as follows.
1. The quality of urea
The high water content, high oil content and formaldehyde content in raw urea will affect the yield of triamine.
2. Liquid ammonia carrying oil
The oil carried in the liquid ammonia of the reactor will make the catalyst in the triamine reactor agglomerate locally and adhere to the surface of the catalyst, reducing the activity of the catalyst. Oil removal filter should be added to play a protective role.
3. Gas retention time in a fluidized bed
If the gas loading is too high, low-temperature amide by-products will be generated, and if the gas loading is too low, high-temperature polymerization by-products will be generated.
4. The role of catalyst in normal pressure method is very large
Due to the low strength and low load of silica gel, it is better to use silica aluminum glue in production.
5. Reaction temperature
In normal pressure melamine production process, temperature has a great influence on the product yield, so it is necessary to strictly control the temperature index.
