Solvent extraction of acetic acid from aqueous solutions: A review

Acetic acid is one of the top commodity chemicals used in various industrial processes. The separation of acetic acid from aqueous solutions is a crucial requirement in the production units. Effective sequestration and recovery of acetic acid is economically beneficial and significant from value addition and environmental protection perspectives. Simple distillation procedures are not usually viable owing to the necessity of a high number of stages and large reflux ratios in the separation column. Several methods such as solvent extraction, extractive distillation, and membrane separation have been studied to retrieve acetic acid from aqueous systems. Of these methods, solvent extraction is preferred due to less consumption of energy and fast mass transfer rates. The efficiency of solvent extraction primarily depends on the solvent chosen for the extraction. The current work is focused on the review of studies that have been extensively carried out for extracting acetic acid from aqueous solutions using various pure solvents and a combination of solvents. The role of modeling and computer-aided simulation studies in the design and evaluation of separation performance is elucidated. Strategies to enhance acetic acid extraction such as salting-out and buffering-out are highlighted. Future prospects are identified to develop sustainable separation systems.