you are using a membrane filtration process to separate an o2/co2 stream with a composition of 80 mol % o2 and flow rate of 2x106 cm3 (stp)/s. a silicone rubber membrane with a thickness of 2x10-3 cm will be used to separate the constituents of the mixture. the permeability of o2 in silicone rubber is 500x10-10 cm3 (stp) cm / [sec cm2 cm hg] and the permeability of co2 in silicone rubber is 3000x10-10 cm3 (stp) cm / [sec cm2 cm hg]. you can assume complete mixing on each side of the membrane. a. if the retentate and permeate pressures are 100 and 20 cm hg, respectively, can 20 % of the feed volume be removed as permeate with a composition of at least 50 mol % co2? if so, what area of membrane is needed to complete this separation? b. what is the maximum percentage of the feed that can be collected as permeate with a composition of at least 40 mol % co2? what is the membrane area under these conditions? c. a two-stage separation is used, in which the permeate of stage 1 is repressurized to 100 cm hg and sent to a second stage as the feed. both stages operate with a permeate pressure of 20 cm hg. if the membrane area of the first and second stages are 3x104 and 5x103 m2, respectively, what is the permeate flow rate and composition obtained from the second stage? what is the retentate co2 mole fraction of the second stage? d. now consider recycling the retentate. what retentate recycling strategy makes sense? calculate the new feed flow rate and composition entering stage 1. e. recalculate the permeate flow rate and composition obtained from the second stage. f. repeat multiple iterations until the stage 2 permeate flow rate and composition does not change within 1%. what are the permeate and retentate flow rates and compositions obtained from the second stage?