Mansour Kalbasi - Department of engineering , Islamic Azad University, Mahshahr branch , Daneshgah Ave., Iran.
Mehdi Karimi Boroujeni - Department of engineering , Islamic Azad University, Mahshahr branch , Daneshgah Ave., Iran.

This work analyses the membrane separation of propane and propylene in mixture with nitrogen, for a feed stream containing 12.5% propane, 12.5% propylene, and 75% nitrogen.In this project, theoretical models for both countercurrent and cocurrent hollow-fiber modules and an efficient numerical solution procedure to solve these models were developed. The models consider effects of pressure drop. A silicone-coated polymeric membrane was selected for separation.The results of the present work showed that countercurrent pattern is more effective in every respect.Parametric studies indicated that propane and propylene mole fraction in the permeate stream increases with increase in the fiber thickness and feed flow rate and decreases with increase in the fiber diameter, and temperature. Also it was found that the optimum pressure difference across the membrane is about 3.3.

membrane separation ; hollow-fiber module ; modeling ; propylene ; propa ne