The tests were carried out in duplicate, and the results presented here were consistent with the average of the same. Feed and permeate samples (upon reaching the steady-state condition), were collected for 1–2 during each test to quantify the concentra- tions of ethanol with a gas chromatograph (GC, Agilent model 6890, coupled with autosampler: Agilent model 7683) using a Hewlett–Packard HP-1 column with a length of 50 m, an external diameter of 0.32mm, a stationary phase composed of 100% polydimethylsiloxane and a film thickness of 1.05 lm.