Page 288 - Separation process engineering

A complete check would require solution with a process simulator.
F. Generalize. The Gilliland correlation is a rapid method for estimating the number of equilibrium
stages in a distillation column. It should not be used for final designs because of its inherent

inaccuracy.

7.4 Summary—Objectives

In this chapter we developed approximate shortcut methods for binary and multicomponent distillation.
You should be able to satisfy the following objectives:
1. Derive the Fenske equation and use it to determine the number of stages required at total reflux and the

splits of NK components
2. Use the Underwood equations to determine the minimum reflux ratio for multicomponent distillation

3. Use the Gilliland correlation to estimate the actual number of stages in a column and the optimum feed
stage location

References

Barnes, F. J., D. N. Hansen, and C. J. King, “Calculation of Minimum Reflux for Distillation Columns
with Multiple Feeds,” Ind. Eng. Chem. Process Des. Develop., 11, 136 (1972).

Erbar, J. H., and R. N. Maddox, Petrol. Refin., 40(5), 183 (1961).
Fenske, M. R., “Fractionation of Straight-Run Pennsylvania Gasoline,” Ind. Eng. Chem., 24, 482
(1932).

Gilliland, E. R., “Multicomponent Rectification,” Ind. Eng. Chem., 32, 1220 (1940).
Hines A. L., and R. N. Maddox, Mass Transfer. Fundamentals and Applications, Prentice Hall,
Englewood Cliffs, New Jersey, 1985.

Humphrey, J. L., and G. E. Keller II, Separation Process Technology, McGraw-Hill, New York,
1997.

King, C. J., Separation Processes, 2nd ed., McGraw-Hill, New York, 1980.
Liddle, C. J., “Improved Shortcut Method for Distillation Calculations,” Chem. Eng., 75(23), 137
(Oct. 21, 1968).

Shiras, R. N., D. N. Hansen and C. H. Gibson, “Calculation of Minimum Reflux in Distillation
Columns,” Ind. Eng. Chem., 42, 871 (1950).
Smith, B. D., Design of Equilibrium Stage Processes, McGraw-Hill, New York, 1963.

Thompson, R. E., “Shortcut Design Method-Minimum Reflux,” AIChE Modular Instructions, Series
B, Vol. 2, 5 (1981).
Underwood, A. J. V., “Fractional Distillation of Multicomponent Mixtures,” Chem. Eng. Prog., 44,
603 (1948).

Wankat, P. C., and J. Hubert, “Use of the Vaporization Efficiency in Closed Form Solutions for
Separation Columns,” Ind. Eng. Chem. Process Des. Develop., 18, 394 (1979).

Winn, F. W., Pet. Refiner, 37, 216 (1958).

Homework

A. Discussion Problems

A1. The Fenske equation: