How does the Ostwald process produce nitric acid from ammonia?

The Ostwald process, developed by the German chemist Wilhelm Ostwald in 1901, is the principal industrial method for manufacturing nitric acid from ammonia.1

The production occurs through the following steps:

• Catalytic Oxidation: Ammonia gas is oxidized by air or oxygen in the presence of a platinum gauze catalyst.1
• Formation of Oxides: Through this process, ammonia is successively oxidized to nitric oxide and then to nitrogen dioxide.1
• Absorption: The nitrogen dioxide is absorbed in water to form nitric acid.1

The resulting solution typically contains 50–70 percent acid by weight, which can be further dehydrated through distillation with sulfuric acid if higher concentrations are required. This process remains a fundamental component of the chemical industry, particularly for the production of fertilizers.12