LAUSR

Abstract Batch reactors can present challenging dynamic control problems because of the large nonlinear changes in process parameters during the batch cycle. Large reactant concentrations at the beginning of the batch produce fast reaction rates and large heat-transfer duties if the reactor temperature is increased too rapidly from its low initial temperature. Exothermic reactions can lead to reactor runaways that exceed maximum temperature/pressure safety constraints. Several papers have studied sophisticated techniques for detecting the potential of an impending runaway and taking corrective action. A complex stability criterion embedded in a model predictive control structure is a recent suggestion for handling the problem. This paper discusses a simple practical technique that has been used in industry for decades. The setpoint of a temperature/pressure controller is ramped up at a reasonable rate, but if the demand for coolant increases too much, the ramp is stopped until the demand for control effort drops down to a normal level.