Purification of crude hydrogen chloride

US4003723A · kind A · utility

Assignee

• Hoechst GmbH · DE

Inventors

• Stefan Schafer · Aachen, DE
• Alexander Ohorodnik · Lechenich, DE
• Klaus Gehrmann · Lechenich, DE
• Albert Mainski · Cologne, DE

Key dates

• Filing date: May 17, 1976
• Grant date: Jan 18, 1977
• Expiry date: May 17, 1996

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C01B7/01
• WIPO field: Materials, metallurgy
• WIPO sector: Chemistry

Abstract

Crude hydrogen chloride gas obtained as a by-product in the production of chloroacetic acids by the catalytic chlorination of acetic acid with chlorine gas in contact with acetic anhydride and/or acetyl chloride, and contaminated with about 0.6 up to 3 % by volume of acetyl chloride is purified. To this end, crude hydrogen chloride gas is introduced into the base portion of a scrubbing zone and scrubbed countercurrently therein with 0.5 up to 20 liter, per normal cubic meter (S.T.P) of hydrogen chloride gas, of a cooled scrubbing liquid under circulation, consisting substantially of 20-80 weight % of concentrated H.sub.2 SO.sub.4, 15-60 weight % of acetic acid, and 5-50 weight % of water. The resulting purified moist hydrogen chloride gas issuing at the head of the scrubbing zone is introduced into the base portion of a drying zone and scrubbed countercurrently with precooled sulfuric acid under circulation.