It is required to separate a mixture of five paraffin’s into light and heavy fraction by using a distillation column with 10 trays, a full reflux condenser and a kettle reboiler. The feed stream (1100 lbmol/hr) consists of 5% (mol %) ethane, 24% propane, 32% n-butane,35% n-pentane and 4% n-hexane at 220°F and 240 psia which enters the column on the sixth tray counting from the top. The condenser and reboiler pressures are 240 and 250 psia respectively. The preliminary design specifications require a reflux ratio of 6.0 and a vapor overhead product of 220 lbmol/hr