Ninety-five percent of the acetone vapor in an 85 vol.% air stream is to be absorbed by countercurrent contact with pure water in a valve tray column with an expected overall tray efficiency of 50%. The column will operate essentially at 20 °C and 101 kPa pressure. Equilibrium data for acetone-water at these conditions are: Mole percent acetone in water 3.30 7.20 11.7 17.1 Acetone partial pressure in air, torr 30.00 62.80 85.4 103.0
Calculate: (a) The minimum value of S/G, the ratio of moles of water per mole of air. (b) The number of equilibrium stages required using a value of S/G of 1.25 times the minimum. (please indicate operating line obviously)