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 Ls/Gs ratio that is 1.4 times the minimum Ls/Gs ratio. At that flow rate, the overall mass-transfer capacity coefficient, KY a, is estimated to be equal to 107 mol/m2. s: ?YA. At the temperature and pressure of the absorber, the equilibrium concentrations are related by
yNH3 = 1.075 xNH3
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
yNH3 = 1.075xNH3
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 Ls/Gs is larger than the minimum Ls/Gs.
c. the composition of the liquid stream flowing by the gas stream when the gas mixture contains 2.0 mol % ammonia.