Method for producing a free acid from the salt thereof

US8809576B2 · kind B2 · utility

Assignee

• EVONIK DEGUSSA GMBH · DE

Inventors

• Alexander Schraven · Issum, DE
• Thomas Tacke · Friedrichsdorf, DE
• Thomas Haas · Munster, DE
• Christoph Kobler · Alzenau, DE
• Dieter Buss · Aschaffenburg, DE
• Axel Ronneburg · Hanau, DE
• Olivier Zehnacker · Dortmund, DE

Key dates

• Filing date: Feb 1, 2010
• Grant date: Aug 19, 2014
• Expiry date: Jun 22, 2031

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07C51/02
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

The invention relates to an improved method for releasing an organic acid, preferably a carbon, sulfone or phosphone acid, particularly an alpha or beta hydroxycarbon acid, from the ammonia salt thereof by releasing and removing ammoniac and simultaneous extraction of the released acid, having an amine as a suitable extraction means from the aqueous phase. This method corresponds to a reactive extraction. The reactive extraction of an organic acid from the aqueous ammonia salt solution thereof can be significantly improved by the use of a strip medium or carrier gas, such as nitrogen, air, water vapor or inert gases such as argon. The released ammoniac is removed from the aqueous solution by the continuous gas flow and can be resupplied into a production process. The free acid can be obtained by a method such as distillation, rectification, crystallization, reextraction, chromatography, adsorption or by a membrane method from the extraction means.