A methanol-water solution containing 60% methanol and 40% water as a mole percentage at a flow rate of 350 kmol/h is fed to a distillation column operating at atmospheric pressure as a mixture of 30% steam-70% liquid, and a head product containing 95% methanol and 5% methanol. A base product is requested. For this separation process, the riflux ratio of 3 will be applied.

Saturated water vapor at 1 atm pressure, used for heating purposes, enters the system directly from the bottom of the column. Using the Mc Cabe Thiele graph method, find the required theoretical number of racks and the location of the feeding rack.

Equilibrium values of the methanol-water system under 1 atm pressure (mol frac.)

\begin{tabular}{|l|l|l|l|l|l|l|l|l|l|l|l|} \hline x & 0 & 0,1 & 0,2 & 0,3 & 0,4 & 0,5 & 0,6 & 0,7 & 0,8 & 0,9 & 1,0 \\ \hline y & 0 & 0,42 & 0,58 & 0,67 & 0,73 & 0,78 & 0,83 & 0,87 & 0,92 & 0,96 & 10,0 \\ \hline \end{tabular} \begin{tabular}{|l|l|l|l|l|l|l|l|l|l|l|l|} \hline x & 0 & 0,1 & 0,2 & 0,3 & 0,4 & 0,5 & 0,6 & 0,7 & 0,8 & 0,9 & 1,0 \\ \hline y & 0 & 0,42 & 0,58 & 0,67 & 0,73 & 0,78 & 0,83 & 0,87 & 0,92 & 0,96 & 10,0 \\ \hline \end{tabular}