The absorber used in Problem is now going to be used by the same industrial company to reduce a dilute air- ammonia mixture from 4.93 mol % NH₃ to the desired 0.2 mol % NH₃. The inlet gas rate will be 136 mol/m².s and the inlet NH₃ -free water rate will flow countercurrent to the rising gas stream, flowing at an actual L_s/G_s ratio that is 1.4 times the minimum L_s/G_s ratio. At that flow rate, the overall mass-transfer capacity coefficient, K_Y a, is estimated to be equal to 107 mol/m². s: ?Y_A. At the temperature and pressure of the absorber, the equilibrium concentrations are related by

y_NH3 = 1.075 x_NH3

Determine:-

a. the kg of ammonia absorbed per second per square meters of cross-sectional area;

b. the height of packing required for the absorption process.

Problem :-

An absorber is being used by an industrial company as a gas scrubber. A dilute air-ammonia mixture, containing 5.0 mol% NH₃ is drawn through the tower countercurrent to an initially ammonia free water stream. The inlet gas stream rate is 136 mol/m².s and the inlet NH₃ -free water rate is 3.4 kg/m².s. At the temperature and pressure of the absorber, the equilibrium concentrations are related by

y_NH3 = 1.075x_NH3

If the exiting gas stream is to contain only 0.2 mol % ammonia, determine

a. the composition of the exiting liquid stream;

b. the ratio of the actual L_s/G_s is larger than the minimum L_s/G_s.

c. the composition of the liquid stream flowing by the gas stream when the gas mixture contains 2.0 mol % ammonia.