in EXCEL $5\mathrm{.}7$ Flash Distillation

When a hot, pressurized liquid is pumped into a tank $($flash unit$)$ at a lower pres$-$

sure, the liquid boils rapidly. This rapid boiling is called a flash. If the liquid con$-$

tains a mixture of chemicals, the vapor and liquid leaving the flash unit will have

different compositions, and the flash unit can be used as a separator. The physical

principle involved is vapor$-$liquid equilibrium; the vapor and liquid leaving the flash

unit are in equilibrium. This allows the composition of the outlet streams to be

determined from the operating temperature and pressure of the flash unit. Multiple

flash units can be used together to separate multicomponent mixtures, as illus$-$

trated in Figure $5\mathrm{.}51.$

rations in Excel

A mixture of methanol, butanol, and ethylene glycol is fed to a flash unit $($Unit $1$ in

Figure $5\mathrm{.}51)$ operating at $165C$ and $7$atm. The liquid from the first flash unit is recom$-$

pressed, reheated, and sent to a second flash unit $($Unit $2)$ operating at $105C$ and $1$

atm. The mixture is fed to the process at a rate of $10,000k\frac{g}{h}.$ Write material balances

for each chemical and solve for the mass flow rate of each product stream $(V_1,V_2,L_2).$

A material balance is simply a mathematical statement that all of the methanol $($for

example$)$ going into the process has to come out again. $($This assumes a steady state

and no chemical reactions.$)$ The following methanol balance is shown as an example:

methanol $inF=$ methanol $in{V}_1+$ methanol $in{V}_2+$ methanol $in{L}_2$

$0\mathrm{.}300*(10,000k\frac{g}{h})=0\mathrm{.}716*V_1+0\mathrm{.}533*V_2+0\mathrm{.}086*L_2$

The compositions of the feed stream $F$ and of the three product streams are

listed here:

PLEASE SOLVE IN EXCEL!!!!!