One thousand cubic feet per hour of a 10 mol% NH3 in air mixture is required to produce nitrogen oxides. This mixture is to be obtained by desorbing an aqueous 20 wt% NH3 solution with air at 20°C. The spent solution should not contain more than 1 wt% NH3. Calculate the volume of packing required for the desorption column. Vapor-liquid equilibrium data for Exercise 6.32 can be used and KGa = 4 lbmovh-ft3-atm partial pressure.