You are asked to design a packed column to recover acetone from air continuously, by absorption with water at 60°F. The air contains 3 mol% acetone, and a 97% recovery is desired. The gas flow rate is 50ft³/min at 60°F, 1 atm. The maximum-allowable gas superficial velocity in the column is 2.4 ft/s. It may be assumed that in the range of operation, Y* = 1.75X, where Y and X are mole ratios for acetone.

Calculate:

(a) The minimum water-to-air molar flow rate ratio.

(b) The maximum acetone concentration possible in the aqueous solution.

(c) The number of theoretical stages for a flow rate ratio of 1.4 times the minimum.

(d) The corresponding number of overall gas transfer units.

(e) The height of packing, assuming Kya = 12.0 lbmollh-ft³-molar ratio difference.

(f) The height of packing as a function of the molar flow rate ratio, assuming that V and HTU remain constant.