Question 3 [Total 25 marks) An air stream is to be separated using a membrane 2.54x10 cm thick and with an oxygen permeability of PX-500x10*10 cm? (STP).cm/(s.cm.cmHg). The concentration of oxygen in the inlet air is 0.209 and the flow rate is 8x109 cm"(STP)/s. The upstream pressure is set at 180cmHg and the downstream at 18cmHg. If the desired reject composition is 0.121 and a*-10, calculate to 4 decimal places, using the cross-flow model: a. the fraction of the feed permeated, [13 marks) b. the permeate composition. Yp (4 marks) c. the area of the membrane required, Am. (Complete the table below (where n=2) and use the values in your solution.) [8 marks) i o f F i. 10'1377 0.121 i1 0.2010 0.1674 0.0929 1.3827 0.8108 irin 0.2642 0.209 0 1.8978 0.6403 X Useful data and formulae: Weller & Steiner Transformations: E - - uy - a' + F I u- 050-45. ( -01+ - 1 + r)] pinan SA tas PnPedi. (9-01 0 = 1-4 i = 1-X (1 - 0) (1 - x) up (1 - xp) u-&' + F (1 - 0) (1 - x)di Am Fidi _PL Pn where, u= -Di + (D22 +2E1 + F230.5 9 [(1-0 (1-a) D D = 0.5()Pl+a] F = -0.5 [4*PL 1] * E = - DF Ph Ph a'(D-1)+F R= S = T = 2D-1 1-D-(ETP) (2D-1)(a*/2-F) fi = (Di-F) + (D? (2 + 2 Ei + P230,5 Simpson's Rule: Saf(x)dx= [(x) + 4f(x) + f(x2) + ... +45(Xn-1) + f(x)] where, h=b-a 1 m