ammóniaszintézise

Ammóniaszintézis is the industrial process for producing ammonia. The primary method used is the Haber-Bosch process, which involves the direct combination of nitrogen and hydrogen gases. Nitrogen is typically sourced from the air, which is about 78% nitrogen. Hydrogen is often obtained from natural gas through steam reforming, or by the electrolysis of water.

The synthesis of ammonia is a reversible exothermic reaction: N2(g) + 3H2(g) ⇌ 2NH3(g). High temperatures favor the rate of reaction, but according to Le Chatelier's principle, lower temperatures would shift the equilibrium towards ammonia production. Therefore, a compromise temperature, typically between 400 and 450 degrees Celsius, is used. High pressures, usually in the range of 150-350 atmospheres, are also employed to maximize the yield of ammonia, as the reaction involves a decrease in the number of gas molecules.

A catalyst, most commonly iron-based, is essential to increase the rate of the reaction without significantly affecting the equilibrium. Without a catalyst, the reaction would proceed too slowly to be economically viable. The ammonia produced is then usually separated from the unreacted nitrogen and hydrogen by cooling the mixture, causing the ammonia to liquefy. The unreacted gases are then recycled back into the process. The ammóniaszintézise is a cornerstone of modern agriculture, providing the nitrogen essential for fertilizers, and is also used in the production of explosives and other chemicals.