3- A continuous fractionating column is required to separate fraction n-heptane (C,H1) and 0.305 mole mixture containing 0.695molefraction n-octane (CH1) into products of 99mole per cent purity. The column is

to operate at101.3 kN/m2 with a vapour velocity of 0.6 m/s.The feed is all liquid at its boiling-point, and this is supplied to the column at 1.25 kg/s. The boiling-point at the top of the column may betaken as 372 K, and the equilibrium data are: mole fraction of heptane 0.96 0.91 0.83 0.74 0.65 0.50 0.37 0.24in vapour mole fraction of heptane0.92 0.82 0.69 0.57 0.46 0.32 0.22 0.13in liquid Determine the minimum reflux ratio required.What diameter column would be required if thereflux used were twice the minimum possible?