= Question 3 (35 Points): A single stage membrane unit is to be used to separate a gaseous mixture of A and B. The feed flow rate is 25 kmol/h at 50C and contains 50% A (by mole). The mole fraction of A in the retentate is 0.20. The membrane thickness, I = 5 um. the pressure on the feed side is = 15 bar, and on the permeate side is 1 bar. The permeability PMA = 50 Barrer and the selectivity is 25. a) (5 Points) Draw a PFD of the membrane unit, indicating the inlet and outlet streams. b) (20 Points): Assuming the complete-mixing model, calculate the permeate composition, the fraction permeated, e, and the required membrane area, Am. c) (10 Points) For processing the same feed, explain how the purity of A in the permeate stream can be increased without increasing the membrane area. What are the drawbacks of that option