Ammonia is important because it is a vital source of nitrogen to support plant life. It is also used industrially to make dyes, plastic, explosives, drugs, nitric acid and ammonium hydroxide. Diluted ammonium hydroxide is used as a household cleaner.
Plants use the nitrogen in ammonia to produce necessary proteins. Urea, ammonium sulfate, ammonium nitrate, ammonium phosphate and pure ammonia are all used as commercial fertilizers for nitrogen-poor soil. Ammonium nitrate is also a component of explosives, ammonium phosphate is used in flame-retardant wood treatments and ammonium sulfate is present in chemicals used to tan leather.
Ammonium salts are used in dry-cell batteries, smelling salts and water treatments. Liquid ammonia is used as an industrial refrigerant. Ammonia makes an ideal refrigerant because it can absorb large amounts of heat without its temperature rising.
Ammonia is commercially produced using the Haber process. In this process, nitrogen from the air and hydrogen obtained from methane are combined under high pressure. Iron and potassium hydroxide are used as catalysts in this reaction. An older method of obtaining ammonia is to heat coal or animal protein and capture the ammonia gas released. Horns, hooves and dung are all protein sources that can be used to produce ammonia this way.