Introduction to nitric acid production

Nitric acid is a strong mineral acid famous for its strong oxidization character. It is widely used throughout the industry in the preparation of other chemicals and other uses. Nitric acid is thus manufactured industrially to meet the needs for its use.

A German chemist, Ostwald, developed the procedure for production of nitric acid industrially in 1914. The process described by him is known as the Ostwald process and is the common industrial method of nitric acid production. The complete process of Ostwald can be described in three abstract steps, explained below.

Nitric Acid Production from the Ostwald Process

• The three steps mentioned above for production of nitric acid are:-

• Oxidation of ammonia into nitric oxide• Oxidation of nitric oxide to Nitrogen dioxide• Absorption of nitrogen dioxide (from step 2)

into water to form Nitric acid

Oxidation of ammonia into nitric oxide

• This process is the reaction of Oxygen present in air with purified ammonia to form Nitric oxide. It is carried out in a special chamber called the catalytic chamber, in which the temperature is maintained at 800 degrees celsius by initially heating the reactant gases and then by the heat liberated due to the exothermic nature of the reaction:

4NH3 + 5O2 → NO + 6H2O + heat

• The catalyst used to increase the speed of the reaction is Platinum.

Oxidation of nitric oxide to Nitrogen dioxide

• This process takes place in the Oxidation chamber. The temperature is maintained at 50 degrees Celsius. The product obtained is Nitrogen dioxide from the following chemical reaction:

• 2NO + O2 → 2NO2

Absorption of nitrogen dioxide (from step 2) into water to form Nitric acid

• The nitrogen dioxide formed above is mixed with more oxygen rich air and passed into the third tower called the Absorption tower. Warm water is trickled from above in this chamber. The Nitrogen dioxide and Oxygen react with water to form Nitric acid as follows:-

4NO2 + 2O2 + H2O → 4HNO3

• The Nitric acid obtained at the end of the process is 50 % concentrated. It is further concentrated to the required limit and then ready for industrial use.

•http://www.tutorvista.com/topic/ostwald-process-in-chemical-equilibrium•http://www.tutorvista.com/chemistry/preparation-of-nitric-acid•http://www.tutorvista.com/chemistry/nitric-acid-production