WATER-IMMISCIBLE MIXTURE SOLVENT/COSOLVENT FOR EXTRACTING ACETIC ACID, A METHOD FOR PRODUCING ACETIC ACID (VARIANTS), A METHOD FOR ANAEROBIC MICROBIAL FERMENTATION FOR OBTAINING ACETIC ACID (VARIANTS), MODIFIED SOLVENT AND A METHOD FOR OBTAINING THEREOF

摘要

A modified water-immiscible solvent useful in the extraction of acetic acid from aqueous streams is a substantially pure mixture of isomers of highly branched dialkyl amines. This solvent is substantially devoid of mono-alkyl amines and alcohols. Solvent mixtures formed of such a modified solvent with a desired cosolvent, preferably a low boiling hydrocarbon which forms an azeotrope with water are useful in the extraction of acetic acid from aqueous gaseous streams. An anaerobic microbial fermentation process for the production of acetic acid employs such solvents, under conditions which limit amide formation by the solvent and thus increase the efficiency of acetic acid recovery. Methods for the direct extraction of acetic acid and the extractive fermentation of acetic acid also employ the modified solvents and increase efficiency of acetic acid production. Such increases in efficiency are also obtained where the energy source for the microbial fermentation contains carbon dioxide and the method includes a carbon dioxide stripping step prior to extraction of acetic acid in solvent.