Question $8$

A two$-$stage flash distillation unit is used to separate a mixture of $1,2-$dichloroethane $($DCE$)$ and $1-$propanol at $1$atm. A feed solution of $35$mol$\%$ DCE enters the first stage at $50$kmo$\frac{l}{h}.$ The

temperatures of the first and second stage are $93C$ and $92C,$ respectively.

a$)$ Determine the expected outlet stream concentrations $($mole fraction$)$ and flowrates $($ kmo$\frac{l}{h}).$

b$)$ The actual second stage vapour concentration is $67$ mol$\%$ DCE. Why might this be different

from your calculated value?A two$-$stage flash distillation unit is used to separate a mixture of $1,2-$dichloroethane $($DCE$)$ and $1-$propanol at $1$atm$.$ A feed solution of $35$mol$\%$ DCE enters the first stage at $50$ kmol $/$ h$.$ The temperatures of the first and second stage are $93^$C and $92^$C$,$ respectively.

a$)$ Determine the expected outlet stream concentrations $($mole fraction$)$ and flowrates $($kmol$/$h$).$

b$)$ The actual second stage vapour concentration is $67$ mol$\%$ DCE. Why might this be different from your calculated value?