Temperature control of an aromatic polyamide batch reactor system

This work presents a case study involving recommendation of the Fiber Division of Union Chemical Laboratories on how to implement a control strategy of an MPD-I (Meta Phenylene Diamine-Isophthaloyl Chloride) batch reactor temperature control system. In this study, a cascade temperature control system is used in which the reactor jacket temperature is used as an intermediate controlled variable. For the optimal reactor temperature trajectory, there will be a heat up period in the middle of the batch to prevent gel formation inside the reactor. In addition, the fact that the reaction is exothermic, particularly during the initial stage of the reaction, accounts for why a coolant is also needed to maintain the reactor temperature. The control system is arranged in a split range fashion since the heat medium and coolant are both used to regulate the reactor temperature. Several possible control strategies are examined for this batch reactor temperature control system, among which a recommendation is made as to which one has the best closed-loop response and also maintains smooth control valve actions.