In: Other
A waste gas stream
containing 5.5% ammonia in air is being stripped of the bulk of the ammonia by absorbing it in water in a tray tower. The liquid to gas ratio on a molal basis is known to be 2.5. Both the inlet gas and inlet water streams enter at 25oC. The inlet and outlet gas streams may be assumed to be saturated with water vapour. During operation a thermocouple in the outlet liquid stream measures a temperature of 35.2oC.
a)Calculate the mole fraction of ammonia on the outlet gas stream and hence the percentage recovery of ammonia in the column
b)Determine the number of ideal stages required for this separation
Data:Heat of Solution= 37000kJkmolNH3-1
Specific Heat of Water= 75kJkmol-1oC-1
Equilibria: In the equation y=mx,
25oC m=0.97
30oCm=1.22
35oCm=1.53