P a g e $13$

Question $3$

$25$ Marks

In a petroleum refinery, liquid state hydrocarbon is stored in a vessel at $493K$ and it is in equilibrium with its vapor phase. The properties of the hydrocarbon are: Density $=0\mathrm{.}63\frac{g}{c}{m}^3,$ Critical temperature $(T_c)=562\mathrm{.}2K,$ Critical pressure $(P_c)=48\mathrm{.}98$ bar and acentric factor $()=0\mathrm{.}210.$ The saturation pressure $(P_{\text{s}\text{a}\text{t}})$ is given as $1912\mathrm{.}86$kPa. The molar mass of the hydrocarbon is $78\frac{g}{m}ol.$

$($i$)$ Calculate the fugacity $($f$)$ of the hydrocarbon at saturation pressure.

$(15$ marks$)$

$($ii$)$ Calculate the fugacity of the liquid hydrocarbon at a total pressure of $2014\mathrm{.}7$ psi. $(10$ marks$)$