# Nitric acid

Ammonia oxidised to a strong oxidising acid; the route to ammonium nitrate fertiliser and explosives, and a large, cheaply avoidable source of nitrous oxide.

Source page: https://www.materialinsights.org/chemicals/nitric_acid/

Commodity chemicals · Acids & alkalis · No. 2

- Single chemical
- Feedstock: Minerals and salts
- about 65.5 Mt HNO3 a year (100% basis)
- 1.8 t CO₂e per t
- HS 280800
 Commodity chemicals · Acids & alkalis · Foundation · Matter

Half the world's nitric acid plants still leak a potent greenhouse gas that costs as little as $1 a tonne to stop.

Chart: Illustration: Nitric acid

##### Where it comes from

Chart: Map of where it comes from

In the Ostwald process ammonia is burnt over platinum-rhodium gauze at about 850-950 C, and the nitrogen oxides are absorbed in water to give 55-68% acid.

##### Three things to know

1. Ammonia makes up 80-90% of nitric acid's cash cost, so cheap gas decides who can produce it profitably.
2. An unabated plant emits about 5-9 kg of nitrous oxide per tonne, equal to 1.4-2.5 t of CO2.
3. Most acid never leaves its site: under about 2% of output is traded, because ammonium nitrate ships far more easily.

##### The journey

1. 1 **Ammonia**About 0.28 t per tonne of acid
2. 2 **Oxidation**Burnt over platinum-rhodium gauze near 900 C
3. 3 **Absorption**Nitrogen oxides absorbed into 55-68% acid
4. 4 **Tail gas**Catalysts strip N2O, expander recovers energy
5. 5 **Neutralisation**Mixed with ammonia into ammonium nitrate
6. 6 **End use**Fertiliser, mining explosives, nylon, polyurethane
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## Other sections

- [Overview](https://www.materialinsights.org/chemicals/nitric_acid/overview/index.md)
- [Correlation](https://www.materialinsights.org/chemicals/nitric_acid/correlation/index.md)
- [Production route](https://www.materialinsights.org/chemicals/nitric_acid/routes/index.md)
- [Production](https://www.materialinsights.org/chemicals/nitric_acid/production/index.md)
- [Feedstocks](https://www.materialinsights.org/chemicals/nitric_acid/feedstocks/index.md)
- [Cycles](https://www.materialinsights.org/chemicals/nitric_acid/cycles/index.md)
- [Trading](https://www.materialinsights.org/chemicals/nitric_acid/trading/index.md)
- [Movement](https://www.materialinsights.org/chemicals/nitric_acid/movement/index.md)
- [Regulation](https://www.materialinsights.org/chemicals/nitric_acid/regulation/index.md)
- [Characteristics](https://www.materialinsights.org/chemicals/nitric_acid/characteristics/index.md)
- [Emissions](https://www.materialinsights.org/chemicals/nitric_acid/emissions/index.md)
- [Relationships](https://www.materialinsights.org/chemicals/nitric_acid/links/index.md)