Description
1. Acetone from an aqueous mixture is to be extracted from a stream with flow rate of
1300 kg/h in a continuous counter current extraction system using trichloroethane as
the solvent.
The stream which initially contains 35% (mass) acetone is to contain only
10% acetone after the treatment.
Find
a) The minimum solvent flow rate required for the extraction
b) The number of stages required if the actual solvent flow rate to be used is 1.5 times of
the minimum solvent flow rate.
c) Flow rates and compositions of the exit streams of each stage
The equilibrium data for the system is given below in weight fractions
Raffinate Extract
Acetone Water TCE Acetone Water TCE
0.55 0.35 0.1 0.6 0.13 0.27
0.5 0.43 0.07 0.5 0.04 0.46
0.4 0.57 0.03 0.4 0.03 0.57
0.3 0.68 0.02 0.3 0.02 0.68
0.2 0.79 0.01 0.2 0.015 0.785
0.1 0.895 0.005 0.1 0.01 0.89
The tie line data is as below in weight fraction
Acetone in raffinate Acetone in extract
0.44 0.56
0.29 0.4
012 0.18
Solve using both equilateral triangle diagram and right angle triangle diagram.