Question 3 (35 Points) It is required to recover 90% of CO2 from an air stream containing 2.5 mol%CO, using dilute caustic solution in a tray column absorber. The air flow rate is 250 kmolh at 15C, 1 atm. It may be assumed that the equilibrium curve is Y = 0.6 X, where Y and X are the mole ratio of CO2 to CO-free carrier gas and liquid, respectively. Calculate: a) (5 Points) the mole fraction of CO2 in the exit air stream? b) (5 Points) the minimum L/V molar flow rate ratio? c) (10 Points) the number of theoretical stages at L/V = 1.25 times the minimum using the graphical method. d) (5 Points) the actual number of required trays? e) (10 Points) the required column diameter? Assume the caustic solution has the same properties as water (P2 = 989 , M2 = 18, v. = 1.0 cp)