$13\mathrm{.}57.$ A storage tank contains a heavy organic liquid. Chemical analysis shows the liquid to

contain $600ppm($molar basis$)$ of water. It is proposed to reduce the water concentra$-$

tion to $50ppm$ by boiling the contents of the tank at constant atmospheric pressure.

Because the water is lighter than the organic, the vapor will be rich in water; contin$-$

uous removal of the vapor serves to reduce the water content of the system. Estimate

the percentage loss of organic $($molar basis$)$ in the boil$-$off process. Comment on the

reasonableness of the proposal.

Suggestion: Designate the system water$(1)/$organic$(2)$ and do unsteady$-$state molar

balances for water and for water $+$ organic. State all assumptions.

Data: $\{\begin{array}{ccc}\text{:}[T_{n_2}=& \text{n}\text{o}\text{r}\text{m}\text{a}\text{l}\text{b}\text{o}\text{i}\text{l}\text{i}\text{n}\text{g}\text{p}\text{o}\text{i}\text{n}\text{t}of\text{o}\text{r}\text{g}\text{a}\text{n}\text{i}\text{c}& =130C.]\\ {}_1^{}=5\mathrm{.}8& \text{f}\text{o}\text{r}\text{w}\text{a}\text{t}\text{e}\text{r}in\text{t}\text{h}\text{e}\text{l}\text{i}\text{q}\text{u}\text{i}\text{d}\text{p}\text{h}\text{a}\text{s}\text{e}at& 130C.\end{array}$