In order to solve the problem of low conversion rate of hydrogen and nitrogen in the reaction process, after the synthesis reaction, the ammonia product was separated from the gas, and the unreacted gas was mixed with fresh hydrogen and nitrogen to participate in the synthesis reaction again.
The reaction formula of synthetic ammonia is as follows (the reaction is reversible, and the reaction conditions on the equal sign are "high temperature and high pressure" and "catalyst")? ：
Extended data:
Main uses of ammonia:
The main uses of ammonia are nitrogen fertilizer, refrigerant and chemical raw materials. Inorganic aspect is mainly used to make ammonia water, liquid ammonia, nitrogen fertilizer (urea, ammonium bicarbonate, etc. ), nitric acid, ammonium salt, soda ash. Organic aspects are widely used in synthetic fibers, plastics, dyes, urea and so on.
Characteristics of synthetic ammonia industry:
1. The demand for chemical fertilizer in agriculture is the lasting driving force for the development of synthetic ammonia industry. The increase of world population brings pressure on food supply, and applying chemical fertilizer is an effective way to increase agricultural output.
Ammonia (that is, ammonia solution) and liquid ammonia are a kind of nitrogen fertilizer; Solid nitrogen fertilizers such as urea, ammonium nitrate and ammonium sulfate and compound fertilizers such as ammonium phosphate and nitrophosphate, which are widely used in agriculture, are mainly produced by synthetic ammonia processing.
2, closely related to the energy industry. Synthetic ammonia production usually takes various fuels as raw materials, and at the same time, fuel is needed to supply energy in the production process. Therefore, synthetic ammonia is a chemical product that consumes a lot of energy. The theoretical energy consumption per ton of liquid ammonia is 2 1.28GJ, and the actual energy consumption is far greater than the theoretical energy consumption, which varies with raw materials, factory scale, technology and management level.
The actual energy consumption of a large ammonia plant with a daily output of 1000t ammonia is about twice the theoretical energy consumption (Table 2 [Actual Energy Consumption of Large Ammonia Plant]).
This process is complex and technology-intensive. Ammonia synthesis is a gas-solid catalytic reaction process in the presence of catalyst at high temperature and high pressure. Because ammonia synthesis catalysts (see inorganic chemical catalysts) are easily poisoned by sulfur compounds, carbon oxides and water vapor (see catalyst poisoning).
However, the feed gas made of various fuels contains different amounts of these substances, so it is necessary to remove harmful substances before sending the feed gas to ammonia synthesis. Therefore, the total process of synthetic ammonia production is long and the process is complex. According to different raw materials, the purification methods are different and there are many processes (see ammonia).
Baidu encyclopedia-synthetic ammonia