Processes for the production of chlorine from hydrogen chloride and oxygen

US9447510B2 · kind B2 · utility

Assignee

• Covestro Deutschland AG · DE

Inventors

• Rainer Weber · Leverkusen, DE
• Jürgen Kintrup · Leverkusen, DE
• Andreas Bulan · Langenfeld, DE
• Friedhelm Kamper · Krefeld, DE

Key dates

• Filing date: May 17, 2007
• Grant date: Sep 20, 2016
• Expiry date: Jan 18, 2031

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y02P20/20
• WIPO field: Materials, metallurgy
• WIPO sector: Chemistry

Abstract

Processes for the production of chlorine by multi-stage oxidation, for example, by thermal reaction of hydrogen chloride with oxygen using catalysts or by non-thermal activated reaction of hydrogen chloride with oxygen, in which the gas mixture formed in the reaction, comprising the target products chlorine and water, unreacted hydrogen chloride and oxygen, and possibly other secondary constituents, such as carbon dioxide and nitrogen, (a) is cooled to condense hydrochloric acid as an aqueous solution of hydrogen chloride and (b) the aqueous solution of hydrogen chloride formed is separated from the gas mixture, characterised in that (c) the separated aqueous solution of hydrogen chloride is fed at least partially to an electrochemical oxidation in which at least part of the hydrogen chloride is oxidised to chlorine, (d) the chlorine gas occurring in step d) is optionally added to the gas mixture occurring in step c), (e) the residues of water present in the gas mixture from steps c) and e), in particular by washing with sulfuric acid, are removed, (f) the chlorine-rich gas mixture forming is freed of oxygen and optionally of secondary constituents.