A storage tank for liquid $n-$octane has a diameter of $30\mathrm{.}0ft$ and a height of $22\mathrm{.}5ft.$ During a typical $24-$h period

the level of liquid octane falls from $18\mathrm{.}5ft$ to $9\mathrm{.}00ft,$ after which fresh octane is pumped into the tank to return

the level to $18\mathrm{.}5ft.$

As the level in the tank falls, nitrogen is fed into the free space to maintain the pressure at $18\mathrm{.}0$ psia; when the

tank is being refilled, the pressure is maintained at $18\mathrm{.}0$ psia by discharging gas from the vapor space to the

environment.

The nitrogen in the tank may be considered saturated with octane vapor at all times. The average tank

temperature is $85\mathrm{.}0F.$ The daily rate at which octane is used is $50236$ gal$/$day or $289862$ lbm$/$day$.$ The magnitude of the variation in absolute pressure at the bottom of the tank is $5\mathrm{.}897$ inches of mercury. Now consider the amount that evaporates. How much octane is lost to the environment during at $24-$h period?