Kapton (R) polyimide was carbonized at 873, 1073 and 1273 K with a heating rate of 1, 3 and 5 K min(-1) and applied to the dehydration of methanol, ethanol and isopropanol by pervaporation. Lowering the heating rate or increasing the carbonization temperature resulted in higher selectivity and a decrease in permeability. X-ray diffraction data revealed that when carbonized at high temperature or with a low heating rate, the membrane had lower interplanar spacing, which corresponded to a reduction in pore size. It was also found that the carbonization temperature had a greater influence on the membrane structure than the heating rate. A comparison between permeability observed from single-component and bi-component feeds indicated that the separation mechanism involved more than molecular sieving alone.