In a distillation column operating at atmospheric pressure and having a partial condenser and a full evaporator, the methanol-water mixture containing 50% by weight of methanol is fed to the column at a flow rate of 1000 kg/hour and distilled. The head product drawn from the column contains 90% methanol by weight, and the base product contains 90% water. The feed stream enters the distillation column as liquid at its boiling point (saturated). Riflax ratio is given as 1. By making appropriate acceptances;

a. Find the actual number of racks and the location of the feed rack when the overall column efficiency is 75%.

b. Calculate the actual number of shelves required if saturated water vapor used for heating is fed to the column bare under the lowest shelf.

c. Which of the conditions a and b do you prefer as the working condition? Explain with reasons.

Equilibrium values (mole fraction) of the methanol-water system under operating conditions

\begin{tabular}{|l|l|l|l|l|l|l|l|l|l|l|l|} \hline x & 0,0 & 0,1 & 0,2 & 0,3 & 0,4 & 0,5 & 0,6 & 0,7 & 0,8 & 0,9 & 1,0 \\ \hline y & 0,0 & 0,42 & 0,58 & 0,67 & 0,73 & 0,78 & 0,83 & 0,87 & 0,92 & 0,96 & 1,0 \\ \hline \end{tabular} \begin{tabular}{|l|l|l|l|l|l|l|l|l|l|l|l|} \hline x & 0,0 & 0,1 & 0,2 & 0,3 & 0,4 & 0,5 & 0,6 & 0,7 & 0,8 & 0,9 & 1,0 \\ \hline y & 0,0 & 0,42 & 0,58 & 0,67 & 0,73 & 0,78 & 0,83 & 0,87 & 0,92 & 0,96 & 1,0 \\ \hline \end{tabular}