Identification of Thermodynamic Coupling Phenomena and Its Relevance on Flux Coupling in Pervaporation for Bio-Refining Butanol from Multicomponent Acetone-Butanol-Ethanol (ABE) Mixtures

•Thermodynamic coupling studied in bio-refining of butanol from ABE feed.•Butanol activity coefficients and volume fractions inhibited by ethanol and acetone.•Second order interaction effects dominant in flux coupling.•Sorption isotherms indicate penetrant-polymer interactions are negligible.•Flux isotherms reveal origin of flux coupling in thermodynamic coupling.