Counter-Current Extraction with Multiple Stages: 2000 kg/hr of an aqueous solution comprising of 45 weight % acetone is contacted with acetone-free isopropyl ether to reduce the concentration of acetone to 10 weight% in the aqueous solution in a multi-step counter current extraction unit.
Determine the number of stages required to perform the above operation if the mass flow rate of isopropyl ether is 2650 kg/hr
The equilibrium and tie line information for the 3 phase system is given below
Water layer (raffinate), mass% Ether layer (extract), mass%
A B C A B C
0.993 0.989 0.984 0.971 0.933 0.847
0.715 0.581 0.487 0.981 0.971 0.955
0.917 0.844 0.012 0.015 0.016 0.019
0.023 0.034 0.044 0.106 0.165 0.0069
0.0141 0.0289 0.0642 0.133 0.255 0.367
0.443 0.464 0.0018 0.0037 0.0079 0.0193
0.005 0.007 0.008 0.589 0.451 0.371
0.019 0.039 0.069 0.108 0.151 0.114
** In this problem, no points will be deducted if you do not draw the auxiliary curve and infer exact tie-lines. T to interpolate existing tie-lines to get an approximate tie line