A packed absorption tower (Zpacking = 25 ft; Internal Diameter = 3 ft) is used to remove carbon dioxide from air by means of a caustic soda solution all at 60F.

a) How much CO2 (in mole %) is removed from the inlet gas?

b) For a gas flow rate of 75 m3 (STP)/min, estimate the gas phase overall mass transfer coefficient FOGah in kmoles/(m3 min). If necessary, you may assume that the properties of the caustic soda solution