E24 Industrial applications of chemical equilibria : the direct and indirect utilization of NH3

Aim: To indicate the important sectors in which ammonia is utilized and the relative importance of these sectors in the world production of NH3


  Ammonia is a colourless gas at room temperature with a strong penetrating smell and a boiling point of -33.5 °C.
It is a readily compressible gas, a pressure of 10 bar at room temperature being sufficient to make it liquid for transportation purposes.

Once liquid, ammonia requires much energy to vaporize it (233 kJ/mol). This property is utilized in cooling installations. Ammonia is also readily soluble in water (see also illustration E16). At 20 °C its solubility in water is 30 mol/L and at 0 °C 53 mol/L. Thus ammonia is usually supplied as an aqueous solution. 25 % solutions (13.3 mol/L with a relative density of 0.91) are used in chemical laboratories.

89.5 % of ammonia is used in the production of artificial fertilizer in which it is present as ammonium nitrate, ammonium sulphate, ammonium hydrogen phosphate, carbamide, or urea (NH2)2CO. Ammonia is also utilized in the production of Nylon® (7.5 %) and explosives (2.5 %), as a solvent and as a refrigerant in industrial cooling installations and for ice rinks (0.5 %).