How is chlorine produced?

Chlorine is produced by passing an electric current through a solution of brine (common salt dissolved in water). This process is called electrolysis. The chemical term for salt is sodium chloride (NaCl).


Essential co-products are caustic soda (sodium hydroxide or NaOH) and hydrogen (H2). All three are highly reactive, and technologies have been developed to separate them and keep them apart. Caustic soda is an alkali and widely-used in many industries, including the food industry, textile production, soap and other cleaning agents, water treatment and effluent control.

See the uses of caustic soda pageChlorine production plant by night - Courtesy of Ineos ChlorVinyls

Hydrogen is a combustible gas used in various processes including the production of hydrogen peroxide and ammonia as well as the removal of sulphur from petroleum derivatives.

Based on their sustainability programmes, more and more companies also use the excess hydrogen in fuel cells to generate electric power.

Chlorine has been manufactured industrially for nearly 120 years now.
See the
uses of chlorine page to learn much more about applications of chlorine.

The three main technologies of producing chlorine are

A typical membrane chlorine production cell room - Courtesy of Ineos ChlorVinylsClick on the process names above to visualize the animations (turn sound on) and download print copies of the diagrams. The PDF images may be used in scientific or technical publications if the source  is mentioned.

Try it out yourself:

Produce your own chlorine!

A colourful animation shows you how you can produce (very small quantities) of chlorine yourself, using only a few everyday tools! Try it out, and send us feedback on how you liked it.  

Download the production process animations

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