Optimal grade transition of the styrene polymerization process with endpoint and path constraints

A combination of dynamic optimization and regulatory control system is proposed for grade transition operation in a continuous stirred tank reactor (CSTR). We discuss an optimal grade transition to minimize the raw material with constraints on manipulated variables, polymer quality and operating condition. Through case study of a free radical styrene polymerization, we show that the adequate endpoint and path constraints can decrease the fluctuations of polymer quality during transition operation and enhance the operation stability.