Separation and Valorization of Chlorine From Tail Gas Streams
Gesa H Dreyhsig1, Merlin Kleoff1, Patrick Voßnacker1
1Institute of Chemistry and Biochemistry, Inorganic Chemistry, Freie Universität Berlin, Berlin, Germany.
Angewandte Chemie (International Ed. in English)
|August 11, 2026
Summary
A novel circular process recycles chlorine from chemical industry tail gas using an ion exchange resin. This sustainable method avoids waste and converts chlorine into valuable base chemicals like 1,2-dichloroethane.
Area of Science:
- Chemical Engineering
- Green Chemistry
- Materials Science
Background:
- The chemical industry produces millions of tons of chlorine-containing tail gas annually.
- Current linear processes neutralize these gases, creating waste and consuming significant caustic soda (NaOH).
Purpose of the Study:
- To develop a sustainable, circular process for recycling chlorine from industrial tail gas streams.
- To valorize chlorine by converting it into valuable base chemicals.
Main Methods:
- Development of a specialized ion exchange resin ([IEx]Cl) for selective chlorine adsorption.
- Regeneration of the resin via heat (80°C) and reduced pressure.
- Direct conversion of adsorbed chlorine with ethylene or carbon monoxide.
Main Results:
- The ion exchange resin ([IEx]Cl) selectively adsorbs chlorine from mixed gas streams.
- Efficient release and regeneration of the resin are achieved at 80°C and reduced pressure.
- Successful conversion of adsorbed chlorine to 1,2-dichloroethane and phosgene.
Conclusions:
- The developed circular process offers a sustainable alternative to linear chlorine neutralization.
- This method enables chlorine recycling and valorization, supporting a circular economy in the chemical industry.
- The ion exchange resin technology is key to this integrated chlorine recovery and conversion process.
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