Question

A distillation column is separating n-hexane from n-heptane using 1-inch ceramic Berl saddles. The allowable flooding in the column is 50%. Average column pressure is 1 atm. Separation in the column is essentially complete, so the distillate is almost pure hexane and the bottoms is almost pure heptane. Feed is a 50-50 mixture and is a saturated liquid. In the top, L/V = 0.8. If F = 1000 lbmol/h and D = 500 lbmol/h, estimate the column diameter required at the top. Properties: n-Hexane: MW 86.17, bp 69°C = 342 K, sp grav = 0.659, viscosity (at 69°) = 0.22 cP n-Heptane: MW 100.2, bp 98.4°C = 371.4 K, sp grav = 0.684, viscosity (at 98.4°) = 0.205 cP You may assume ideal gas for vapor densities and Water density at 69°C = 0.9783 g/ml.