Distillation of Multicomponent Alcohol Mixture. A feed of 30 mol % methanol (A), 20% ethanol (B), 15% n-propanol (C), and 35% n-butanol (D) is distilled at 101.32 kPa abs pressure to give a distillate composition containing 95.0 mol % methanol and a residue composition containing 5.0% methanol and the other components as calculated. The feed is below the boiling point, so that q = 1.1. The operating reflux ratio is 3.0. Assume that Raoult's law applies and use vapor-pressure data from Problem 11.7-3. Calculate the following:
Composition and amounts of distillate and bottoms for a feed of 100 mol/h.
Top and bottom temperatures and number of stages at total reflux. (Also, calculate the distribution of the other components.)
Minimum reflux ratio, number of stages at R = 3.00, and feed-tray location.