Question

A saturated liquid feed at 1000.0 kmol/h that is 8.0 mol% ethane, 33.0 mol% propane, 49.0 mol% n-butane, and 10.0 mol% n-pentane is fed to a distillation column operating at 5.0 atm. The column has a total condenser and a partial reboiler. Recovery of propane in the distillate is 99.7%, and n-butane recovery in the bottoms is 99.8%. a) Find N min from the Fenske equation (hand calculation). b) Find (L/D) min from the Underwood equation (hand calculation). c) Use L/D = 1.15(L/D) min, and estimate N and N feed from Gilliland correlation (hand caculation). Use DePriester charts. Assume relative volatility is constant at the value calculated at the bubble-point temperature of the feed. For bubble point calculation, choose propane as the reference component. Choose n-butane (the HK) as the reference component for other calculations.

Answer 1