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Comparative Study on Different IMC based Controller for a Nonlinear pH Neutralization Process

M. Nandhini, Dr. M. Florance Mary, Dr. R. Ananda Natarajan


There are significant research interests in the pH control problem because of its industrial importance and the fact that pH process is one of the most difficult challenges to control.  A control strategy based on internal model controller for (hydrochloric acid and sodium hydroxide) pH neutralization process has been developed by identifying its second order transfer function.  Here, the flow rate of acid is kept constant and base flow rate is varied by using controller design based on internal model control strategy. The process of identifying the system model based on the mass balance equation is presented.  The comparative study on IMC with filter for different lambda, IMC-PID for different lambda and PI controller are presented. The validated result are evaluated on the basis of the simulation carried on pH neutralization process.


Internal Model Control, IMC with Filter, IMC-PID, pH Neutralization Process

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Carlos E. Garcia and Manfred Morari, “Internal Model Control. 1. A Unifying Review and Some New Results,” Ind. Eng. Chem. Process Des. Dev., Vol. 21, 1982, pp. 309.

“Internal model control. 2. Design procedure for multivariable systems,” Ind. Eng. Chem. Process Des. Dev., vol. 24, pp. 472–484, 1985

Jean-Paul Calvet and YamanArkun, “Feedforward and Feedback Linearization of Nonlinear Systems and Its Implementation Using Internal Model Control (IMC),” Ind. Eng. Chem. Res., Vol. 27, No. 10, 1988.

E. P. Nahas, M. A. Henson and D. E. Seborg, “Nonlinear Internal Model Control Strategy for Neural Network Models” Computers chem. Engng. Vol. 16, pp. 1039-1057, 1992

Q. G. Wang, “Partial internal model control,” Dept. Elect. Eng., Nat. Univ. Singapore, Singapore, Internal Rep., 1996.

McAvoy, T. J., Hsu, E., and Lowenthal, S. “Dynamics of pH in a controlled stirred tank reactor”, Ind. Eng. Chem. Process Des. Dev., volume 11, 1972, pp. 68-70.

AlexD. Kalafatis, LiupingWang,”Linearizing feedforward–feedback control of pH processes based on the Wiener model”, Journal of process control, 2005, pp.103-112.

M. D. Brown, G.Lightbody, G.W.Irwin,”Non-linear internal model control using local model network” Ind. Eng. Chem. Res. 1998, vol.37, 2729-2740.

Snehal D. Kambale1, Sebastian George, Prof. R. G. Zope,”Controllers used in pH Neutralization Process: A Review” Computers and Chemical Engineering, Vol-28, pp. 1475–1487, 2004.


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