(330b) Separation of Propane from Nitrogen Using Polydimethyl Siloxane Thin Film Composite Membranes

Polyvinylidene difluoride (PVDF) membranes coated with poly (dimethyl siloxane) (PDMS) thin film composite membranes were investigated for the separation of propane from nitrogen. An experimental study was performed to evaluate the effects of various operating conditions (i.e., temperature, pressure, feed composition) on the membrane permselectivity with propane/nitrogen mixtures. It was shown that the membrane could be adapted to propane/nitrogen separation, and the membrane selectivity increased with a decrease in temperature and an increase in the feed pressure. The permeability of nitrogen was independent of feed pressure and increased with the temperature increasing. However, the permeability of propane increased with the pressure increasing and the temperature decreasing. The relationship between the permeability of propane and nitrogen and feed temperature can be represented in an Arrhenius equation. At 18◦C and 500 kPa, the membrane exhibited a propane/nitrogen permeability ratio of as high as 10 for feed mixtures containing 6¨C30 mol% propane.

Supported by China Postdoctoral Science Foundation (20060400436), the Major State Basic Research Program of China (No. 2003CB615701), National Natural Science Foundation of China (No. 20576059,No.20676067), CNPC Innovation Foundation (No. 05051143).

Corresponding author. E-mail:lijiding@mail.tsinghua.edu.cn (J D Li)

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