(Separation by Gas Permeation) The Prism gas permeation process is developed by the Monstanto Company is selective for hydrogen when using hollow-fiber membranes made of siliconecoated polysulphone. A feed gas at 16.7 MPa and 40°C containing 42.4 H2, 7.0 CH4, and 0.5 N2 kmol/h is separated by the membrane into a retentate gas at 16.2 MPa and a permeate gas at 4.56 MPa.

a) Assume the membrane is non-permeable to nitrogen, the recovery of H2 is 60.38%, and the mole ratio of CH4 to H2 in the permeate is 0.0117. Calculate the total flow rate of the retentate and permeate gases and the flow rates of each component in them. Label and draw everything on a process flow diagram.

b) Compute the percent purity of the hydrogen in the permeate gas.