Reactive extraction of acetic acid

Abstract

Acetic acid is an important carboxylic acid widely used in chemical, pharmaceutical, food and other industries. The growing importance of biological production (fermentation) expressed with new routes and increasing production rates, leads to look for technologies of downstream processing for product separation. The reactive extraction can be used for the recovery of an acetic acid from aqueous solution.The reactive extraction with specific extractant and a proper combination of extractant and diluents provides the higher capacity and selectivity of an acetic acid. The recovery of acetic acid by reactive extraction is studied using an organic solvent such as toluene, petroleum ether and n-hexane. The feed concentration of acetic acid in the aqueous solution ranges in between 0.1 to 0.4 gmol/l. The extraction of acetic acid from aqueous solution (feed concentration 0.4 gmol/lit) with organic solvent gives the distribution coefficient (KD) in toluene, petroleum ether and N-Hexane solvents equal to 1.29, 0.79 and 0.6 respectively. Further, the reactive extraction is carried out with the mixtures of extractant–diluents. The tri-iso-octylamine is used as an extractant. The extraction of acetic acid with 40% of tri-iso-octylamine in an organic solvent shows the highest distribution coefficient for toluene, petroleum ether and n-hexane. These are 3.65, 2.70 and 2.63 respectively. By comparing results, it can be concluded that using the mixtures of extractant–diluents, the extraction is significantly improved.