Selective Separation of Carboxylic Acids Obtained by Succinic Acid Fermentation Using Facilitated Pertraction

Abstract

Formic, acetic, and succinic acids have been selectively separated from their mixture obtained by A. succinogenes fermentation using facilitated pertraction with tri-n-octylamine (TOA). This technique allows recovering formic and acetic acids from the mixture, the feed phase raffinate containing only succinic acid. The pH-gradient between the feed and stripping phases, carrier concentration in liquid membrane, and mixing intensity of the two aqueous phases control the selectivity of acids pertraction, TOA concentration exhibiting the most important influence. At pH-value of feed phase 2, pH-value of stripping phase 10, rotation speed 500 rpm, the maximum selectivity factor (S = 133) was reached for the carrier concentration 70 g L−1.