Page 207 - Separation process engineering

F. Problems Requiring Other Resources

F1. A distillation column separating ethanol from water uses open steam heating. The bottoms
composition is 0.00001 mole fraction ethanol. The inlet steam is pure water vapor and is
superheated to 700°F. The pressure is 1.0 atm. The ratio of bottoms to steam flow rate is B/S =
2.0. Find the slope of the bottom operating line.

F2. The paper by McCabe and Thiele (1925) is a classic paper in chemical engineering. Read it.
a. Write a one-page critique of the paper.

b. McCabe and Thiele (1925) show a method for finding the feed lines and middle operating lines
for a column with two feeds that is not illustrated here. Generalize this approach when q ≠ 1.0.
F3.* If we wish to separate the following systems by distillation, is CMO valid?

a. Methanol and water
b. Isopropanol and water

c. Acetic acid and water
d. n-Butane from n-pentane

e. Benzene from toluene

G. Computer Problems

G1.
a. * Solve Example 4-4 with a process simulator.

b. Repeat this problem but with L/D = 1.5.
G2. Use a process simulator and find the optimum feed stage and total number of equilibrium stages
for Problem 3.D6. Report the VLE correlation used. Record the values of Q condenser and Q reboiler

(in Btu/h).

G3.* Write a computer, spreadsheet, or calculator program to find the number of equilibrium stages
and the optimum feed plate location for a binary distillation with a constant relative volatility.
System will have CMO, saturated liquid reflux, total condenser, and a partial reboiler. The given
variables will be F, z , q x , x , α, and L /D. Test your program by solving the following
D
0
F
B