mixture of $32\%$ ethanol and $68\%$ water as moles is fed to the distillation column with a flow rate of $1000$ mol $/h$ as cold liquid.

$1$ mol of steam condenses against each $4$ mol of feed in the feed rack. Distillation column is at atmospheric pressure and total

condenser and open steam heating are used. It is desired to separate $75\%$ ethanol in mole distillate and $10\%$ ethanol in mole.

Saturated steam at $1$atm pressure is used in the boiler. Using the balance data below,

a$-$ Find the flow rate of the upper and lower currents.

b$-$ Determine the minimum number of steps.

c$-$ Determine the minimum backflow rate.

In the case of $d-RD=1,5RD,$ min;

I. Determine the ideal number of steps.

ii$.$ Find the composition of the liquid and vapor streams leaving the $7$ th and $10$ th stages.

iii. If the Murphree yield is $0\mathrm{.}7,$ find the actual stage number and determine the stage where the feed is made.

e$-$ Calculate the flow rate of the steam used $($the enthalpy of saturated steam at $1$atm can be taken as $=970\mathrm{.}3Bt\frac{u}{l}b,$

evaporation latent heat of the mixture in the boiler as $910Bt\frac{u}{l}b).$