Abstract: The absorption of CO2 from 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 R1R2CHNHCH2COOK, in which R1 and R2 are n-alkyl radicals and the radicals R1 and R2 together have 2 to 4 carbon atoms, affords a high CO2 absorption capacity per unit weight in the cyclical operation of absorption and desorption.

Abstract: CO2 is absorbed from a gas mixture by bringing the gas mixture into contact with an absorption medium comprising water and at least one amine of formula (I) R1R2NCH2CH2CHR4NHR3,??(I) where R1, R2 and R3 are, independently of one another, C1-C3-alkyl radicals, R4 is hydrogen, methyl or ethyl and the radicals R1, R2, R3 and R4 together comprise not more than 5 carbon atoms.

Abstract: An absorption medium comprising water and at least one amine of formula (I) where R2 is hydrogen or an alkyl radical having 1 to 4 carbon atoms, R2 is an alkyl radical having 1 to 4 carbon atoms, R3 and R5 are each independently alkyl radicals having 1 to 6 carbon atoms and R4 and R6 are each independently hydrogen or alkyl radicals having 1 to 6 carbon atoms where R3 and R4 may combine to form the bridging radical —(CH2)n—, —CH2CH2OCH2CH2— or —CH2CH2NR7CH2CH2— with n=2 to 5 and R2=hydrogen or an alkyl radical having 1 to 6 carbon atoms, brings about an improved CO2 absorption capacity in the absorption of CO2 from a gas mixture by contacting the gas mixture with the absorption medium.

Abstract: The absorption of CO2 from 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 R1R2CHNHCH2COOK, in which R1 and R2 are n-alkyl radicals and the radicals R1 and R2 together have 2 to 4 carbon atoms, affords a high CO2 absorption capacity per unit weight in the cyclical operation of absorption and desorption.

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.

Abstract: 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 R1, R2 and R3, 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.

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.

Abstract: 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 R1, R2 and R3, 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.

Abstract: The present invention relates to a process for preparing hydroxycarboxylic acids, preferably ?- and ?-hydroxycarboxylic acids, from ammonium carboxylates of the general formula in which R1, R2 and R3 are each independently H, OH, (C1-C6)-alkyl optionally substituted by a hydroxyl group, (C1-C6)-alkenyl optionally substituted by a hydroxyl group, (C1-C6)-alkoxy optionally substituted by a hydroxyl group, (C1-C6) -alkylthio-(C1-C6)-alkyl optionally substituted by a hydroxyl group, (C6-C10)-aryl optionally substituted by a hydroxyl group, (C7-C12)-aralkyl optionally substituted by a hydroxyl group, (C3-C5)-heteroaryl optionally substituted by a hydroxyl group, with the proviso that at least one hydroxyl group is present in at least one R1, R2 and R3 radical, preferably R1?H, CH3, CH2CH3, C6H5, (CH2)2SCH3 and R2?H, CH3 and R3?OH, equally preferably R1?CH2OH, CHOHCH3 and R2?R3?H, CH3, more preferably R1?R2?CH3 and R3?OH, equally more preferably R1?CH2OH, R2?CH3 and R3?H, comprising the following step: heatin