sieve-tray column

A depropanizer is a distillation operation encountered in almost all oil refineries. Our task here is to design a sieve-tray column to separate 1000 mol/s of a mixture containing 100 mol/s of ethane, 300 mol/s of propane, 500 mol/s of n-butane, and 100 mol/s of n-pentane at 298 K and 15 atm. The distillate should contain no more than 3.5 mol/s of n-butane, and the bottoms should contain no more than 3.5 mol/s of propane. The trays should operate at about 70% of flooding (Taylor and Krishna, 1993)