Page 193 - Separation process engineering

effect of changing variables will be, as a diagnostic when the computer program appears to be
malfunctioning, and as a diagnostic when the column appears to be malfunctioning (Kister, 1995).
Because of its visual impact, we have used the McCabe-Thiele diagram extensively to explore a variety
of distillation systems.

4.16 Summary—Objectives

In this long chapter we developed the stage-by-stage balances for distillation columns and showed how to
solve these equations when CMO is valid. You should now be able to satisfy the following objectives:
1. Write the mass and energy balances and equilibrium expressions for any stage in a column

2. Explain what CMO is, and determine if CMO is valid in a given situation
3. Derive the operating equations for CMO systems

4. Calculate the feed quality and determine its effect on flow rates. Plot the feed line on a y-x diagram
5. Determine the number of stages required, using the Lewis method and the McCabe-Thiele method

6. Develop and explain composition, temperature, and flow profiles
7. Solve any binary distillation problem where CMO is valid. This includes:

a. Open steam
b. Multiple feeds

c. Partial condensers and total reboiler
d. Side streams

e. Intermediate reboilers and condensers
f. Stripping and enriching columns

g. Total and minimum reflux
h. Overall and Murphree efficiencies

i. Simulation problems

j. Any combination of the above
8. Include the effects of subcooled reflux or superheated boilup in your McCabe-Thiele and Lewis
analyses

9. Develop flowcharts for any binary distillation problem

References

Binous, H., “Equilibrium-Staged Separations Using MATLAB and Mathematica,” Chem. Engr.
Educ., 42 (2), 69 (Spring 2008).

Brown, G. G. et al., Unit Operations, Wiley, New York, 1950.
Burns, M. A., and J. C. Sung, “Design of Separation Units Using Spreadsheets,” Chem. Engr. Educ.,
30 (1), 62 (Winter 1996).

Foust, A. S., L. A. Wenzel, C. W. Clump, L. Maus, and L. B. Andersen, Principles of Unit
Operations, 2nd ed., Wiley, New York, 1980.
Himmelblau, D. M., Basic Principles and Calculations in Chemical Engineering, 3rd ed., Prentice

Hall, Upper Saddle River, NJ, 1974.
Horwitz, B. A., “Hardware, Software, Nowhere,” Chem. Engr. Progress, 94 (9), 69 (Sept. 1998).
Kister, H. Z., Distillation Operation, McGraw-Hill, New York, 1990.