WHY IT IS WORTH TO CONSIDER THE RECOVERY OF Cl2 FROM HClaq
Chlorine is used as an oxidising agent in several organic processes and gaseous HCl is often released as a by-product. Usually the gaseous HCl (hydrogen chloride) is then absorbed in water and used for different purposes or sold as such. It is not always possible to find an use for the acid and the discharge to waste treatment is not a satisfactory solution, both for economic and environmental reasons. Therefore the idea to convert the HCl aqueous solution (hydrochloric acid) back to chlorine is considered more and more as an attractive way to solve the problem.
What are the benefits of chlorine recovery from hydrochloric acid? We can mention some of them:
- chlorine, that is in any case required to feed the organic processes, is generated at plant site and therefore there is no risk deriving from its transportation
- no costs related to hydrochloric acid disposal
- the business is made independent from Cl2 and HCl prices
- possible constraints to plants expansions are removed, in the sense that the organic process plant can be expanded without the need to verify in advance if it will be possible to find an use for the hydrochloric acid
- money saving. Even if the valorisation of the hydrochloric acid (provided that it is sold or used somewhere) depends on local circumstances, we can state that a plant for the production of chlorine starting from HCl would cost significantly less than a traditional chlor-alkali plant which produced the same amount of chlorine.
- Interesting for regions with high Cl2 demand or excess caustic soda.
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