TEMPERATURE CONTROL OF HIGHLY EXOTHERMIC BATCH POLYMERIZATION REACTORS

In this article st highly exothermic batch polymerization reactor is c onsidered. The reactor is simplified as a mixing tank with the interna l heat generation treated as a disturbance. A fuzzy-hybrid-PID-feedbac k (FH-PID) control structure is developed in which the output of fuzzy hybrid portion is used to adjust the set point of a PID controller to compensate for the effect of the major disturbance, the heat of react ion. In this way, the hybrid portion of the controller does not influe nce the stability of the original PID control system. A fuzzy model wa s constructed to estimate the heat of reaction inside the fuzzy hybrid block. The fuzzy parameters of the hybrid portion do not depend on th e process model and can be estimated from the transient response obtai ned with a conventional PID controller. This FH-PLD control strategy h as been applied to the temperature control of batch solution and batch inverse emulsion polymerizations of acrylamide in a I gallon pilot sc ale reactor. The results show that this fuzzy hybrid-PID-feedback cont rol strategy improves the control performance of the batch polymerizat ion reactor. (C) 1997 John Wiley & Sons, Inc.