onsider a distillation column for separating ethanol from water at 1 atm. The following specifications are set: Feed: 10 mol% ethanol (bubble-point liquid) Bottoms: 1 mol% ethanol Distillate: 80 mol% ethanol (saturated liquid) Reilux ratio: 1.5 times the minimum Constant molar overflow may be assumed and vapor-liquid equilibrium data are given in Exercise 7.29.
(a) How many theoretical plates are required above and below the feed if a plate column is used?
(b) How many transfer units are required above and below the feed if a packed column is used?
(c) Assuming that the plate efficiency is approximately 80% and the plate spacing is 18 in., how high is the plate column?
(d) Using an HOG value of 1.2 ft., how high is the packed column?
(e) Assuming that you had HTU data available only on the benzenetoluene system, how would you go about applying the data to obtain the HTU for the ethanol-water system?