title: Extraction and Esterification of Low-Titer Short-Chain Volatile Fatty Acids from Anaerobic Fermentation with Ionic Liquids.
abstract: Ionic liquids can both act as a solvent and mediate esterification to valorize low-titer volatile fatty acids and generate organic solvents from renewable carbon sources including biowaste and CO2 . In this study, four phosphonium ionic liquids were tested for single-stage extraction of acetic acid from a dilute stream and esterification to ethyl acetate with added ethanol and heat. The esterification proceeded with a maximum conversion of 85.9±1.3 % after 30 min at 75 °C at a 1:1 stoichiometric ratio of reactants. Extraction and esterification can be tailored using mixed-anion ionic liquids; this is demonstrated herein using a common trihexyl(tetradecyl)phosphonium cation and a mixed chloride and bis(trifluoromethylsulfonyl)imide anion ionic liquid. As a further proof-of-concept, ethyl acetate was generated from an ionic liquid-driven esterification of an acetic acid extractant generated using CO2 as the only carbon source by microbial electrosynthesis.
authors.affiliation: Center for Microbial Ecology and Technology (CMET), Ghent University, Coupure Links 653, 9000 Gent, Belgium.
authors.forename: Stephen J
authors.identifier: 0000-0002-3791-5787
authors.initials: SJ
authors.lastname: Andersen
authors.affiliation: Research Group SynBioC, Department of Sustainable Organic Chemistry and Technology, Ghent University, Coupure Links 653, 9000 Gent, Belgium.
authors.forename: Jan K E T
authors.initials: JK
authors.lastname: Berton
authors.affiliation: Research Group SynBioC, Department of Sustainable Organic Chemistry and Technology, Ghent University, Coupure Links 653, 9000 Gent, Belgium.|Center for Microbial Ecology and Technology (CMET), Ghent University, Coupure Links 653, 9000 Gent, Belgium.
authors.forename: Pieter
authors.initials: P
authors.lastname: Naert
authors.affiliation: Center for Microbial Ecology and Technology (CMET), Ghent University, Coupure Links 653, 9000 Gent, Belgium.
authors.forename: Sylvia
authors.initials: S
authors.lastname: Gildemyn
authors.affiliation: Center for Microbial Ecology and Technology (CMET), Ghent University, Coupure Links 653, 9000 Gent, Belgium.
authors.forename: Korneel
authors.initials: K
authors.lastname: Rabaey
authors.affiliation: Research Group SynBioC, Department of Sustainable Organic Chemistry and Technology, Ghent University, Coupure Links 653, 9000 Gent, Belgium. chris.stevens@ugent.be.
authors.forename: Christian V
authors.identifier: 0000-0003-4393-5327
authors.initials: CV
authors.lastname: Stevens
mesh_terms: D000693:Anaerobiosis; D004572:Electrolysis; D004951:Esterification; D005232:Fatty Acids, Volatile / Q000737:chemistry* / Q000302:isolation & purification* / Q000378:metabolism; D005285:Fermentation; D006863:Hydrogen-Ion Concentration; D052578:Ionic Liquids / Q000737:chemistry*; D012997:Solvents / Q000737:chemistry; D013696:Temperature
chemical_list: D005232:Fatty Acids, Volatile; D052578:Ionic Liquids; D012997:Solvents
keywords: biorefinery; esterification; ionic liquids; sustainable chemistry; volatile fatty acids