Question $3(40$ points$)$

Consider a distillation column with a feed of $36$kmo$\frac{l}{h}$ benzene, $72$kmo$\frac{l}{h}$

o$-$xylene and $45$kmo$\frac{l}{h}$ toluene at $750mmHg$ and $384K.$

The vapour pressures can be calculated by using the Antoine equation:

$In(P^0)=A-[\frac{B}{T+C}]$

where: $P^0=$ vapour pressure $(mmHg)$

$A,B,C=$ Antoine coefficients

$T=$ temperature $(K)$

In table below the Antoine coefficients are given:

a$.$ If the ratio of benzene to toluene in the distillate is $99$ and the overhead

split fraction of benzene is $0\mathrm{.}98,$ calculate the minimum number of trays.

b$.$ Calculate the composition of benzene, toluene and o$-$xylene in the

distillate and in the bottom product.

c$.$ Determine the dew point temperature at a pressure of $1\mathrm{.}5$ bar, if the

distillate product is a saturated vapour containing $55$mol$\%$ benzene, $40$

mol$\%$ toluene, and $5$mol$\%$ o$-$xylene

d$.$ If you would have a small amount of $H_{2}S$ gas $($non$-$condensable$)$ in the

feed what type of condenser would you use, a total or partial condenser.

Explain why