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Optimal control of a two-stage reactor system

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Abstract

Optimal operation policies were investigated for a batch reactor system with two different operation stages. At the end of the first nonisothermal stage one of the reactants was added. Since that moment the reactor was operated isothermally. In each stage behavior of the reactor was described by a set of differential equations. The maximum conversion problem was investigated subject to various operating constraints. Dynamic optimization based on the control vector parametrization was used to find the optimal control profile. Gradients of the resulting nonlinear programming problem were obtained by adjoint method based on the optimal control theory.

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Abbreviations

c A-F :

concentration of components A-F mol m−3

c sB :

concentration of added component B at switching times mol m−3

c WD :

required minimum value of the concentration of the component D at final time mol m−3

f:

system of state equations

F:

component of the cost function or constraints evaluated over a period of time

G:

component of the cost function or constraints evaluated at the final conditions

H:

Hamiltonian function

I:

identity matrix

J:

cost function or constraints

k:

number of constraints

k 1 :

first rate constant m3mol−1min−1

k 2 :

second rate constant min−1

L:

integral part of gradients

n:

number of iterations

p:

vector of time-independent parameters

P:

number of intervals

S:

amount of the solution of the component B added after the first stage with concentration c sB m3

t:

time min

t P :

processing time for both reaction stages min

t s :

switching time min

u:

profile of the reactor temperature for the first reaction stage K

u(t):

control vector

V 1 :

volume of the material loaded into the first reactor m3

V 2 :

volume of the material loaded into the second reactor m3

x(t):

state vector

Δ:

discontinuity of the state vector at switching times

λ:

vector of Lagrange multipliers

0:

initial time

i:

i-th segment

j:

j-th function of iteration

−:

time immediately before the switching time

+:

time immediately after the switching time

*:

optimum value

References

  1. Srinivasan, B., Palanki, S., and Bonvin, D., Comput. Chem. Eng. 27, 1 (2003).

    Article  CAS  Google Scholar 

  2. Bonvin, D., J. Process Control 8, 355 (1998).

    Article  CAS  Google Scholar 

  3. Dostál, P., Bakošová, M., and Bobál, V., Chem. Pap. 58, 184 (2004).

    Google Scholar 

  4. Lin, S. H. and Cheng, K. W., Desalination 133, 41 (2001).

    Article  CAS  Google Scholar 

  5. Zhao, H., Isaacs, S. H., Søeberg, H., and Kümmel, M., Water Res. 28, 535 (1994).

    Article  CAS  Google Scholar 

  6. Zhao, H., Isaacs, S. H., Søeberg, H., and Kümmel, M., Water Res. 29, 535 (1995).

    Article  CAS  Google Scholar 

  7. Coelho, M. A. Z., Russo, C., and Araújo, O. Q. F., Water Res. 34, 2809 (2000).

    Article  CAS  Google Scholar 

  8. Isaacs, S., Water Sci. Technol. 35, 225 (1997).

    Article  CAS  Google Scholar 

  9. Barton, P. I., Banga, J. R., and Galán, S., Comput. Chem. Eng. 24, 2171 (2000).

    Article  CAS  Google Scholar 

  10. Schlegel, M. and Marquardt, W., J. Process Control 16, 275 (2006).

    Article  CAS  Google Scholar 

  11. Manon, P., Roubinet, C. V., and Gilles, G., Cont. Eng. Prac. 10, 133 (2002).

    Article  Google Scholar 

  12. Bemporad, A. and Morari, M., Automatica 35, 407 (1999).

    Article  Google Scholar 

  13. Avraam, M. P., Shah, N., and Pantelides, C. C., Comput. Chem. Eng. 22, 221 (1998).

    Article  Google Scholar 

  14. Biegler, L. T., Cervantes, A. M., and Wächter, A., Chem. Eng. Sci. 57, 575 (2002).

    Article  CAS  Google Scholar 

  15. Cuthrell, J. E. and Biegler, L. T., AIChE J. 33, 1257 (1987).

    Article  CAS  Google Scholar 

  16. Logsdon, J. S. and Biegler, L. T., Ind. Eng. Chem. Res. 28, 1628 (1989).

    Article  CAS  Google Scholar 

  17. Feehery, W. F., Ph.D. Thesis. Massachusetts Institute of Technology, Cambridge, 1998.

  18. Rosen, O. and Luus, R., Comput. Chem. Eng. 15, 273 (1991).

    Article  CAS  Google Scholar 

  19. Caracotsios, M. and Stewart, W. E., Comput. Chem. Eng. 9, 359 (1985).

    Article  CAS  Google Scholar 

  20. Vassiliadis, V. S., Sargent, R. W. H., and Pantelides, C. C., Ind. Eng. Chem. Res. 33, 2111, 2123 (1994).

    Article  CAS  Google Scholar 

  21. Ruban, A. I., J. Comput. Syst. Sci. Int. 36, 536 (1997).

    Google Scholar 

  22. Goh, C. J. and Teo, K. L., Automatica 24, 3 (1988).

    Article  Google Scholar 

  23. Bryson, A. E. and Ho, Y. C., Applied Optimal Control — Optimization, Estimation and Control. Hemisphere Publishing Corporation, Washington, 1975.

    Google Scholar 

  24. Hirmajer, T. and Fikar, M., Technical Report, FCFT SUT, Bratislava, Slovakia, 2005.

    Google Scholar 

  25. Pontryagin, L. S., Boltyanskii, V. G., Gamkrelidze, R. V., and Mishchenko, E. F., The Mathematical Theory of Optimal Processes. Wiley, New York, 1962.

    Google Scholar 

  26. Fikar, M. and Latifi, M. A., Technical Report, LSGC CNRS, Nancy, France; FCFT SUT, Bratislava, Slovakia, 2001.

    Google Scholar 

  27. Petzold, L. R. and Hindmarsh, A. C., Technical Report, LLNL, California, 1997.

    Google Scholar 

  28. Schittkowski, K., Technical Report, University of Bayreuth, Bayreuth, Germany, 1981.

    Google Scholar 

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Hirmajer, T., Fikar, M. Optimal control of a two-stage reactor system. Chem. Pap. 60, 381–387 (2006). https://doi.org/10.2478/s11696-006-0069-x

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  • DOI: https://doi.org/10.2478/s11696-006-0069-x

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