Hydrochloric acid
Hydrochloric acid is a cheap, mostly by-product acid from chlorine chemistry, used for steel pickling, oil wells, water treatment and mineral processing.
Commodity chemicals · Acids & alkalis · No. 3
- Single chemical
- Feedstock: Minerals and salts
- not published; most HCl is captive or recycled within chlorine chains
- 0.9 t CO₂e per t
- HS 280610
In August 2026 a tonne of hydrochloric acid cost about $27 in China but six times as much in America.
Chart: Illustration: Hydrochloric acid
Where it comes from
Chart: Map of where it comes from
Most HCl appears as a by-product whenever chlorine is used but not built into a product; chlor-alkali plants also burn spare chlorine in hydrogen, about 0.97 t per tonne of acid.
Three things to know
- Most hydrochloric acid is a by-product, so its supply follows chlorine and isocyanate plants rather than what acid buyers want.
- Acid is too cheap to ship far: prices ranged from about $27/t in China to $162/t in the US in August 2026.
- When more than 5 Mt of Chinese chlor-alkali capacity went into maintenance in mid-2026, Chinese acid prices rose about 33%.
The journey
- 1 Chlorine chemistryIsocyanates and chlorinations release HCl
- 2 Direct synthesisSurplus chlorine burnt in hydrogen
- 3 AbsorptionGas dissolved in water to 30-36%
- 4 Local deliveryRubber-lined tankers within a few hundred km
- 5 End useSteel pickling, oil wells, water treatment