Pure water was used to remove 90% ammonia from the gas mixture in packed bed tower. The gas
mixture which contain 5 mol% NH 3 enters from the bottom of the column at flow rate of 100 kmol/h.
Pure water enters from the top of the column at a flow rate 1.5 times minimum pure water flow rate
(1.5 L’ min ). The column cross sectional area is 0.20 m 2 . The equilibrium relationship for NH 3 and water
is given by y = 0.8915x. The film mass transfer coefficients are given as k’ y a = 0.0739 kmol/s.m 3 and
k’ x a = 0.169 kmol/s.m 3 . Determine the height of the packed tower using liquid film mass transfer
coefficient, k’ x a.
Equilibrium relationship between concentration of solute in liquid and vapor phase is,
y = 0.8915 x
The liquid phase mass transfer coefficient = 0.169 kmol/s.m3
Operating flow rate of liquid solvent = 1.5 minimum flow rate of liquid solvent.
Cross-sectional area of tower = 0.2 m2