Question

Q2) Consider 100 kmole/h of feed which includes 20 mole % ethanol in water. We wish to
concentrate ethanol to 60 % with a bottom product that is no more than 2 % ethanol. The feed
is a saturated liquid. The reflux ratio should be 1.5*Rmin (Rmin: Minimum reflux ratio). If the
trays have a Murphree efficiency of 75 % based on the vapor, calculate the number of stages
and optimal feed stage. The column is run at 1 atm.
Table: Vapor-Liquid Equilibrium Data for Ethanol (1) –Water (2) Mixture
T, ? xEtoh yEtoh
100 0 0
95.5 0.019 0.17
89 0.0721 0.3891
86.7 0.099 0.4375
85.3 0.1238 0.4704
84.1 0.1661 0.5089
82.7 0.2337 0.5445
82.3 0.2608 0.558
81.5 0.3273 0.5826
80.7 0.3965 0.6122
79.7 0.5198 0.6599
79.3 0.5732 0.6841
78.74 0.6763 0.7385
78.41 0.7472 0.7815
78.15 0.8943 0.8943
78.3 1 1

Answer 1