Method for the separation of and purification of an aqueous mixture consisting of the main components acetic acid and formic acid

US6695952B1 · kind B1 · utility

Assignee

• Consortium für elektrochemische Industrie GmbH · DE

Inventors

• Christoph Rüdinger · Starnberg, DE
• Harald Voit · Reischach, DE
• Michael Hallmann · Braunau am Inn, AT
• Mehmet Gunaltay · Emmerting, DE
• Barbara Geborene Neé Reil Wild · Bietigheim-Bissingen, DE
• Hans-Jurgen Eberle · Munich, DE

Key dates

• Filing date: Jan 9, 2002
• Grant date: Feb 24, 2004
• Expiry date: Feb 22, 2022

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10S203/20
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

A method for the separation and purification of an aqueous mixture of main components, namely acetic acid and formic acid and non-volatiles by extraction, uses a solvent in a circulatory system. A raffinate stream is mixed with the larger proportion of water from a solvent stripper column (11) for the removal of water. The extraction stream is introduced into a solvent distillation column (8), from which in a first step involving the use of a mixture (A) containing a larger proportion of the solvent is separated out via a header and a mixture (B) of formic acid, water and solvent is separated out via a side offtake and a mixture (C) of acetic acid and non-volatiles is also separated out. A mixture (B) is introduced into a formic acid distillation column (4) for further processing, and a mixture (C) is introduced into an acetic acid distillation column (5), and purified acetic acid is subsequently isolated in the acetic acid distillation column (5) from the header. Pure formic acid is isolated at the settling basin of the formic acid distillation column (4).