What are the disadvantages of industrial synthetic ammonia by iron catalyst method?

Iron catalyst method is commonly used in industrial synthetic ammonia, but it also has some shortcomings. The following are the main disadvantages of industrial synthetic ammonia by iron catalyst method:

1. Low reaction rate: the reaction rate of ammonia synthesis by iron catalyst method is relatively slow. Although this method can be carried out at lower temperature and pressure, it takes a long time to reach the ideal yield, which leads to lower production efficiency.

2. High pressure and high temperature conditions: Although the operating conditions of iron catalyst method are relatively light compared with other synthetic ammonia methods, high pressure and high temperature conditions are still needed. This not only increases the equipment cost and energy consumption, but also poses a challenge to safety and environmental protection.

3. Short service life of catalyst: Iron catalyst is easy to be polluted and corroded in the reaction process, resulting in short service life. The common pollutants are sulfide, phosphide and toxic substances, which will reduce the catalytic activity of the catalyst, require frequent replacement or regeneration of the catalyst, and increase the production cost.

4. High energy consumption: A large amount of energy is needed in the process of iron catalyst ammonia synthesis, which is mainly used for heating, compression and refrigeration. Because the reaction of synthetic ammonia production is exothermic, it needs to consume a lot of energy to maintain the reaction temperature, which increases the production cost and puts pressure on energy.

5. Difficulty in product separation: Synthetic ammonia produced by iron catalyst method is usually mixed with a large number of inert gases (such as nitrogen and hydrogen), which needs subsequent separation and purification. The complexity and energy consumption of this process increase the production cost.

However, despite some shortcomings, the iron catalyst method is still one of the important methods for industrial synthetic ammonia. Scientists and engineers are constantly trying to improve this method to overcome these problems and improve the efficiency and sustainability of synthetic ammonia.