Evonik Degussa Gmbh

Evonik Roehm Gmbh

Evonik Operations Gmbh

Evonik Rohm Gmbh

Alexander Schraven

Thomas Haas

Thomas Tacke

Achim Marx

Manfred Neumann

Rolf Schneider

Benjamin Willy

Olivier Zehnacker

Christoph Kobler

Axel Ronneburg

Dieter Buss

Jörn Rolker

Stefanie Rinker

Günter Knaup

Eva Maria Wittmann

Daniel Dembkowski

Jochen Niemeyer

Eva-Maria Wittmann

The absorption of COfrom a gas mixture by contacting the gas mixture with an absorption medium that comprises water and 5 to 50 wt % of amino acid salts of formula RRCHNHCHCOOK, in which Rand Rare n-alkyl radicals and the radicals Rand Rtogether have 2 to 4 carbon atoms, affords a high COabsorption capacity per unit weight in the cyclical operation of absorption and desorption.

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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.

Method for producing a free acid from the salt thereof

A process for the preparation of free carboxylic acids including: A) preparation of carboxylic acid by a biological cell located in an aqueous medium with addition of an amine of formula (I) where R, Rand R, independently of one another, are identical or different, branched or unbranched, optionally substituted hydrocarbon radicals or H; B) for cases where the added amine A) is water-soluble, addition of a water-insoluble amine of formula (I), where, in A) or B), a multiphase system is obtained and the corresponding ammonium carboxylate is formed from the water-insoluble amine and the carboxylic acid; C) removal of the water-insoluble phase; and D) heating of the water-insoluble phase with release of free carboxylic acid.

Method for the production of free carboxylic acids

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Issum, Germany

Alexander Schraven