In the manufacture of methyl ethyl ketone from butanol, the product is separated from unreacted butanol by distillation. The feed to the column consists of a mixture of 0.90 mol fraction MEK, 0.10 mol fraction 2-butanol, with a trace of trichloroethane.
The feed rate to the column is 20 kmol/h and the feed temperature 35 °C. The specifications required are: top product 0.99 mol fraction MEK; bottom product 0.99 mol fraction butanol.
Design a column for this separation. The column will operate at essentially atmospheric pressure. Use a reflux ratio 1.5 times the minimum.
a. Determine the minimum reflux ratio.
b. Determine the number of theoretical stages.
c. Estimate the stage efficiency.
d. Determine the number of actual stages needed.
e. Design a suitable sieve plate for conditions below the feed point
Equilibrium data for the system MEK -2-butanol, mol fractions MEK: