In the example below, the company decides to install some measures to reduce benzene pollution to the atmosphere. This includes piping the vent gases through a secondary condenser cooled with chilled water and operating at $8\backslash$deg C$.$ How much benzene would be collected at the condenser $($kg$/$year$)?$ The remaining vent gases are sent to a carbon filter system. If the capacity of the carbon filters are $80,000-$kg of organics before break$-$through occurs, how often do the filters have to be changed? Benzene liquid density at $8\backslash$deg C is $891-$kg$/$m$3.$ Vapor pressure is given by the Antoine equation:

Log $10$P $=$ A$-$ B$/($C$+$T$),$ where P is in mmHg$,$ T in $\backslash$deg C; A $=6\mathrm{.}87987,$ B $=1196\mathrm{.}76$ and C $=219\mathrm{.}161.$If the recovered benzene is pure enough to be reused, and the cost for the chilled water$/$condenser$/$carbon filter system installation is $$60,000,$ is this a worthwhile investment?

EX: The Maleic Chemical Company stores benzene in several $20-m^3$ tanks. Each tank is filled as it empties and triggers

a low level sensor when $1-m^3$ full. The filling stops at the $19-m^3$ level $($high level sensor$).$ As the tank fills, the

benzene vapors in the headspace above the liquid level is vented out. The average temperature at which benzene

is stored is $20C.$ How much benzene is lost to the atmosphere this way each year?

The total quantity of benzene used is $500,000,000-k\frac{g}{y}$ear. Assume benzene behaves as an ideal gas.

Benzene Data: $MW=78$; Liquid Density at $20C$ is $878-k\frac{g}{m^3}$; Vapor Pressure at $20C$ is $70-mmHc$

We need to determine the total number of times the tanks are filled each year, ar

the amount of benzene lost in each fill.

Headspace Volume displaced, each fill $(V)=18-\frac{m^3}{?}$ fill

Vapor Pressure of Benzene $(p_1)=70-mmHg$

Note: $1-$Pa$.m^3=1-$ J

$P_T=p_1+p_2$

$P_T=$ Total Pressure $($atmospheric$)$

$p_1=$ partial pressure $($benzene$)$

$n=p_1\frac{V}{R}.T=\frac{70-mmHg133\mathrm{.}3-P\frac{a}{m}mHg18-\frac{m^3}{f}\text{i}\text{l}\text{l}}{(8\mathrm{.}314\frac{J}{m}ol.K)293K}=69-mo\frac{l}{?}$ fill

Or$,$ in $\{$:$kg=6={?}^{**}9(mol)78\frac{g}{m}ol1-k\frac{g}{1000}-g)=5\mathrm{.}38-k\frac{g}{f}$ill

Total benzene loss$/$year $=31637\mathrm{.}6$ fills $5\mathrm{.}38-k\frac{g}{f}il=170174-kg$