${6\mathrm{.}27}^a.$ Gilliland correlation applied to a binary system.

Use the Gilliland correlation to estimate the number of ideal stages required for the separation of Example $6\mathrm{.}4.$ Assume that, for the system benzene and toluene at atmospheric pressure, the relative volatility is constant at $=2\mathrm{.}5.$ Use the results of Problems $6\mathrm{.}15$ and $6\mathrm{.}16.$ Use the Kirkbride equation to estimate the optimum feed$-$stage location.

Answer: $14\mathrm{.}4$ ideal stages