Chemical processes show dynamic behavior during start-up, shutdown, and when upsets occur under steady state conditions

Abstarct This paper addresses the control problem of starting up a non-isothermal CSTR. The startup problem is of dual objectives. One objective is to fill up the tank and the other is to achieve certain reaction conversion. The two objectives compete with each other because each has a different gain sign. Consequently, standard PI algorithms may not perform well. In fact, nonlinear control algorithms can be tested for the startup control problem. However, to avoid computational complexity brought in by such nonlinear controllers, Fuzzy Logic Control (FLC) can be a simple and suitable alternative. Specifically, FLC algorithm is applied for the start-up problem and its performance is compared to that of PI controller with gain scheduling.