Propaneis separated from propylene by distillation.The compounds have close

boiling points, and the relative volatility will be low. For a feed composition of

10% w/w propane, 90% w/w propylene, estimate the number of theoretical

plates needed to produce propylene overhead with a minimum purity

of 99.5 mol percent. The column will operate with a reflux ratio of 20. The

feed will be at its boiling point. Take the relative volatility as constant at 1.1.