Nitrous Oxide Production

Making nitrous oxide on a small scale in labs and at schools is broadly the same principal as the large scale industrial manufacture.

Production

Apart from the natural sources outline above, nitrous oxide can also be produced by chemical methods for human use, which will be outlined later. The most common method for its production is:

  • Ammonium nitrate decomposition by heat

This is the most common method for the production of nitrous oxide at an industrial scale and consists in heating ammonium nitrate (NH4NO3) up to 240º Celsius. The decomposition of the nitrate by this process creates a mixture of nitrous oxide and extremely hot vapour. At the same time, this process also produces impurities, including ammonia, nitrogen and other nitrogen oxides. Water vapour and other impurities cleaned with a mixture of water, caustic soda and sulphuric acid, with any traces of nitrogen being removed from the storing place of the nitrous oxide, after this being compressed.

  • Direct oxidation of ammonia

This method is costlier than the one outline above, but may someday be competitive with it.  It uses as a catalyst manganese dioxide-bismuth oxide to produce nitrous oxide and was developed in Japan. In this process creates impurities in the form of higher oxides of nitrogen. The result of the uncatalyzed ammonia oxidation is manly nitrogen and water.

  • Heating of a solution of sulfamic acid and nitric acid

This method, widely used in Bulgaria, is produced by heating a solution of sulfamic acid and nitric acid. Given that the mixing rate is closely controlled there is no explosive danger in this reaction.

  • By-product in the synthesis of adipic acid

Large quantities of nitrous oxide are produced as a by-product in the synthesis of adipic acid (adipic acid is one of reactants used in the production of nylon). This method as the potential to become a major commercial source, but requires the removal of impurities in the form of higher oxides of nitrogen and organic materials. At this time most of the gas decomposes before release due to environmental reasons. More environment friendly, which replace hydrogen peroxide with nitric acid oxidation, may succeed given that they do not generate nitrogen oxide by-products.

  • Hydroxylammonium chloride reacting with sodium nitrite

When the nitrite is mixed into a hydroxylamine solution, nitrous oxide is produced with the by-product of salt water. If the reverse happens, hydroxylamine mixed into a nitrite solution and thus the nitrites in excess, there is the forming of additional higher oxides of nitrogen.