Extraction of 1,3-Propanediol with Aqueous Two-Phase Systems Formed by Protic Ionic Liquids and Inorganic Salts

Abstract

Extraction of 1,3-propanediol (PDO) was reported using the protic ionic liquid (PIL)-based aqueous two-phase system (ATPS). In this study, combinations of PILs (pyrrolidinium formate [Pyrr][HCOO] and propionate [Pyrr][C₂H₅COO] and inorganic salts (K₃PO₄ and K₂HPO₄) as phase-forming components of ATPS, were examined. PDO was successfully extracted with all ATPSs and the best extractability was shown in an ATPS composed of [Pyrr][C₂H₅COO] and K₃PO₄. By examining the composition, the highest distribution ratio of 4.52, which is approximately comparable with those of aprotic ionic liquid-based ATPS, was obtained.