Page 262 - Separation process engineering

2. Use bubble-point calculations to determine new temperatures on each stage
3. Use a matrix approach to solve the energy balances for new flow rates.

4. Explain the difference between the bubble-point and Naphtali-Sandholm methods

References

Amundson, N. R., and A. J. Pontinen, “Multicomponent Distillation Calculations on a Large Digital

Computer,” Ind. Engr. Chem, 50, 730 (1958).
Barnicki, S. D., “How Good Are Your Data?” Chem. Engr. Progress, 98 (6), 58 (June 2002).
Carlson, E. C., “Don’t Gamble with Physical Properties for Simulations,” Chem. Engr. Progress, 92

(10), 35 (Oct. 1996).
Fredenslund, A., J. Gmehling, and P. Rasmussen, Vapor-Liquid Equilibria Using UNIFAC: A
Group-Contribution Method, Elsevier, Amsterdam, 1977.

Holland, D. D., Fundamentals of Multicomponent Distillation, McGraw-Hill, New York, 1981.
nd
King, C. J., Separation Processes, 2 ed., McGraw-Hill, New York, 1981.
Lapidus, L. Digital Computation for Chemical Engineers, McGraw-Hill, New York, 1962.

Maxwell, J. B., Data Book on Hydrocarbons, Van Nostrand, Princeton, NJ, 1950.
Naphtali, L. M., and D. P. Sandholm, “Multicomponent Separation Calculations by Linearization,”
AIChE Journal, 17 (1), 148 (1971).
th
Poling, B. E., J. M. Prausnitz, and J. P. O’Connell, The Properties of Gases and Liquids, 5 ed.,
McGraw-Hill, New York, 2001.
Sadeq, J., H. A. Duarte, and R. W. Serth, “Anomalous Results from Process Simulators,” Chem.
Engr. Education, 31 (1), 46 (Winter 1997).

Schad, R. C., “Make the Most of Process Simulation,” Chem. Engr. Progress, 94 (1), 21 (Jan. 1998).
Seider, W. D., J. D. Seader, and D. R. Lewin, Process Design Principles, Wiley, New York, 1999.

Smith, B. D., Design of Equilibrium Stage Processes, McGraw-Hill, New York, 1963.

Walas, S. M., Phase Equilibria in Chemical Engineering, Butterworth, Boston, 1985.
Wankat, P. C., Equilibrium-Staged Separations, Prentice Hall, Upper Saddle River, NJ, 1988.

Homework

A. Discussion Problems

A1. In the matrix approach, we assumed K = K(T, p). How would the flowchart in Figure 6-1 change
if K = K(T, p, x)?
i
A2. The method described in this chapter is a simulation method because the number of stages and the
feed and withdrawal locations must all be specified. How do you determine the optimum feed
stage?

A3. Develop your key relations chart for this chapter.

A4. In a multicomponent simulation program for distillation the loops are nested. The outermost loop
is mole fractions, next is flow rates and the innermost loop is temperature.
1. Mole fractions are the outermost loop because,

a. Many distillation problems can be done without this loop.
b. Changing mole fractions often do not have a major effect on K values.