You are working for a company in the oil and gas sector, where your team is given the assignment to design a gas permeation module for the separation of a gaseous mixture containing 20 mol% A and 80 mol% B. For a preliminary design, your boss asks you to compute the required membrane area to reach a permeate flow rate P = 0.4F containing 70 mol% A.  

Explain why this requirement cannot be met and that your boss has to decide to either have a permeate that is P = 0.4F or to have a permeate that contains 70 mol% A. The governing equations for the membrane module are given below. Assume the feed flow rate F, the feed composition z, the forward and backward pressure p1 and p2, the membrane permeabilities BA and BB, and the membrane thickness l are known.  Tip: Degrees of freedom of the governing equations.