Answer to Question #283562 in Chemical Engineering for hays

Question

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.

Answer 1

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