A distillation column is separating $150$kmol$*h-1$ of a four$-$component mixture. The composition and

the relative volatility of the feed are shown in Table below. The column recovers $95\%$ of Component

B to the distillate and $95\%$ of Component $C$ to the bottom's product. The feed to the column is a

saturated liquid.

Table. Feed characteristics of a four$-$component mixture

a$)$ Calculate the minimum number of stages.

b$)$ Calculate the molar flowrate and composition of the distillate and bottoms products for this

column. State any assumptions you need to make.

c$)$ Calculate the minimum reflux ratio.

d$)$ Estimate the number of theoretical stages required if the reflux ratio is $25\%$ greater than the

minimum reflux ratio.