The pervaporative transport interactions between trihexyl(tetradecyl)phosphonium bis(trifluoromethylsulfonyl)imide ionic liquid-based membrane and the components of ABE fermentation broth were elucidated in this study. Acetone has a suggested viscosity decreasing effect on the ionic liquid and exhibited coupling effect with 1-butanol. Temperature increase consistently caused increase on 1-butanol permeance. The presence of acetic and butyric acids has no observed effect on 1-butanol and water permeation. No permeation of ethanol and acetic acid was noted, while butyric acid permeation can be suppressed by pH control. The membrane was proven stable in separating 1-butanol from actual fermentation broth for long period of time.