Process for purification of aqueous solutions containing hydrogen sulfide, hydrogen cyanide, and ammonia

US5236557A · kind A · utility

Assignee

• Hoechst GmbH · DE

Inventors

• Thomas Muller · Bad Homburg vor der Höhe, DE
• Rolf-Dieter Fischer · Oberhausen, DE
• Ulrich Gerhardus · Oberhausen, DE
• Norbert Leder · Oberhausen, DE
• Klaus Poloszyk · Dorsten, DE
• Peter Schneller · Oberhausen, DE
• Wolfgang Brunke · Bottrop, DE

Key dates

• Filing date: Dec 18, 1991
• Grant date: Aug 17, 1993
• Expiry date: Dec 18, 2011

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10S210/904
• WIPO field: Environmental technology
• WIPO sector: Chemistry

Abstract

Aqueous solutions which are contaminated by hydrogen sulfide, hydrogen cyanide, and ammonia are brought to a pH of about 3 or less after their formation and treated with an inert gas in a stripping column to remove the sulfide and cyanide. The pH of the solution is then increased to about 10 or more and the solution is again treated with an inert gas in a second stripping column to remove the ammonia.