RECOVERY OF VOLATILE CARBOXYLIC ACIDS BY A STRIPPER- EXTRACTOR SYSTEM

摘要

A process for recovering a volatile carboxylic acid from an aqueous stream comprising same, the process comprising the steps of: (i) steam stripping the carboxylic acid from the aqueous stream, which aqueous stream is produced by a conversion process using a lignocellulosic feedstock as a substrate, the steam stripping comprising contacting the aqueous stream with steam by flowing the aqueous stream and the steam countercurrent to one another, thereby producing a vapour stream comprising vapourized carboxylic acid and steam and a stripped aqueous stream; (ii) extracting the vapourized carboxylic acid with an organic solvent by contacting the vapour stream with the organic solvent to produce (a) a stream comprising the organic solvent and the carboxylic acid and (b) the steam at least substantially depleted of the carboxylic acid, wherein the organic solvent has an atmospheric boiling point of at least about 150°C and is insoluble in water; (iii) returning the steam from step (ii) to the steam stripping step (step i) to further strip the carboxylic acid from the aqueous stream; and (iv) separating the carboxylic acid from the organic solvent.