Discrete Optimization using String Encodings for the Synthesis of Complete Chemical Processes
The use of discrete programming techniques for the synthesis of process flowsheets in chemical engineering is a well established approach. Recently, improvements in the basic algorithms have been made to deal with the generation of complete processes, including heat exchange networks and processes with reactors, absorbers, flash units, etc. This paper describes a new approach to the use of dynamic programming using string encodings both for subproblem definition and for solution description. These encodings, combined with the use of dynamic hash tables, are used to implement a dynamic programming based optimization algorithm for the synthesis of chemical processes. The implementation shows an increase in both efficiency and usefulness.
KeywordsGlobal nonlinear optimization discrete programming process synthesis nonconvex optimization
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- 2.G. H. Ballinger, R. Bañares-Alcántara, D. Costello, E. S. Fraga, J. King, J. Krabbe, D. M. Laing, R. C. McKinnel, J. W. Ponton, N. Skilling, and M. W. Spenceley, Developing an Environment for Creative Process Design, Chemical Engineering Research & Design, 72, A3, pp. 316–324 (1994).Google Scholar
- 7.J. E. Hendry and R. R. Hughes, Generating separation process flowsheets, Chem. Eng. Prog., 68 (6), pp. 71–76 (1972).Google Scholar
- 9.E. S. Fraga and K. I. M. McKinnon, CHiPS: A Process Synthesis Package, Chemical Engineering Research & Design, 72, A3, pp. 389–394 (1994).Google Scholar
- 10.C. Stair and E. S. Fraga, Optimization of Unit Operating Conditions for Heat Integrated Processes Using Genetic Algorithms, Proc. 1995 I.Chem.E. Research Event, pp. 95–97, Institution of Chemical Engineering, Rugby, U.K. (1995).Google Scholar
- 11.N. S. Dhallu and W. R. Johns, Synthesis of Distillation Trains with Heat Integration, I. Chem. E. Symp. Series, 109, pp. 23–42 (1988).Google Scholar
- 13.E. S. Fraga and K. I. M. McKinnon, Portable Code for Process Synthesis Using Workstation Clusters and Distributed Memory Multicomputers, Computers chem. Engng, 19, 6 /7, pp. 759–773 (1995).Google Scholar
- 14.B. W. Kernighan and D. M. Ritchie, The C Programming Language, Prentice-Hall International, Inc., London (1978).Google Scholar
- 15.P.-A. Larson, Dynamic Hashing, Comm. ACM, pp. 446–457 (1988).Google Scholar
- 16.E. Bartel, C Code Implementation of a Dynamic Hashing Algorithm, Institut fuer Informatik, TU Muenchen, Muenchen, Germany (1993). Available via Internet, URL ftp://ftp.inria.fr/prog/libraries/dynhash-1.0.shar.gz.Google Scholar
- 18.A. J. V. Underwood, Fractional Distillation of Multicomponent Mixtures, Chem. Eng. Prog., 44, 8, pp. 603–614 (1948).Google Scholar
- 21.National Engineering Laboratory, PPDS. Physical Properties Data Service, The Institution of Chemical Engineers, Rugby, England (1981).Google Scholar
- 13.J. M. Douglas, Conceptual Design of Chemical Processes, McGraw Hill (1988).Google Scholar