2. Mass and energy balances around a multistage distillation column A mixture that contains 46 wt% acetone (CH3COCH3), 27% acetic acid (CH3COOH), and 27% acetic anhydride [(CH3CO)20] is distilled at P=1

atm. The feed enters the distillation column at 348 K at a rate of 15,000 kg/h. The distillate (overhead product) is essentially pure acetone, and the bottoms product contains 1% of the acetone in the feed. The vapor effluent from the top of the column enters a condenser at 329 K and emerges as a liquid at 303 K. Half of the condensate is withdrawn as the overhead (distillate) product, and the remainder is refluxed back to the column. The liquid leaving the bottom of the column goes into a steam-heated reboiler, in which it is partially vaporized. The vapor leaving the reboiler is returned to the column at a temperature of 398 K, and the residual liquid, also at 398 K, constitutes the bottoms product. A flowchart of the process and thermodynamic data for the process materials follow.