A distillation column separating benzene from toluene is shown below. Pressure is 1 bar. The feed containing 60 (mol %) benzene is fed to the distillation column at a rate of 1000 mol/h. Feed is saturated vapour. The vapor leaving the top of the column, which contains 98 (mol %) benzene (y = 0.98), is completely condensed

and 20% of it is taken off as the distillate, while the rest (the reflux) is recycled to the top of the column. The flow rate of the saturated liquid distillate (D is 300 mol/h. The system has a partial reboiler. The boilup is returned to the bottom of the column as saturated vapor and the bottom product is 95% toluene. A vapor side stream is withdrawn above the feed stage. The side stream is 80 (mol %) benzene.

Find Qr.

A distillation column separating benzene from toluene is shown below. Pressure is 1 bar. The feed containing 60(mol%) benzene is fed to the distillation column at a rate of 1000mol/h. Feed is saturated vapour. The vapor leaving the top of the column, which contains 98(mol%) benzene (y1=0.98), is completely condensed and 20% of it is taken off as the distillate, while the rest (the reflux) is recycled to the top of the column. The flow rate of the saturated liquid distillate (D) is 300 mol/h. The system has a partial reboiler. The boilup is returned to the bottom of the column as saturated vapor and the bottom product is 95% toluene. A vapor side stream is withdrawn above the feed stage. The side stream is 80(mol%) benzene. Find QR