Acetone is to be recovered from a $5$ per cent acetone$-$air mixture by scrubbing with water in a packed tower using counter current flow. The liquid rate is $0\mathrm{.}85k\frac{g}{m^2}s$ and the gas rate is $0\mathrm{.}5k\frac{g}{m}2s.$

The overall absorption coefficient $K_{Ga}$ may be taken as partial pressure difference$]$ and the gas film resistance controls the process. What height of tower is required tower to remove $98$ per cent of the acetone? The equilibrium data for the mixture are:

Mole fraction $of$ acetone $in$ gas $0\mathrm{.}0099,0\mathrm{.}0196,0\mathrm{.}0361,0\mathrm{.}0400$

Mole fraction $of$ acetone $in$ liquid $0\mathrm{.}0076,0\mathrm{.}0156,0\mathrm{.}0306,0\mathrm{.}0333$