Retrofit design of heat exchanger network of a fluid catalytic cracking plant and control based on MPC

Nowadays, the optimal control of a heat-integrated plant becomes one of the most important research areas in the chemical industry. The heat transfer between the process and recycle flows may generate instability. Accordingly, the advanced control techniques have the challenging task of assuring the safety of the process operation and providing tight control for the heat integrated plants. Investigation of an entire fluid catalytic cracking (FCC) plant taking into account its complex dynamic behaviour for heat integration design and operation has not been studied yet. The reactor–regenerator, the fractionation column and the heat exchanger network are included in the present study. Using the data from an industrial plant, a complex FCC process simulator was built. The structure of the optimal heat exchange network (HEN) was designed and implemented in the simulator. Comparison between PID and MPC control strategy was done and the incentives of the proposed MPC are revealed.

► Dynamic simulator of a complex fluid catalytic cracking industrial plant was built.
► New HEN design was developed and implemented in the FCC plant dynamic simulator.
► Estimation of 9% cost reduction from total annual cost of HEN using the new HEN.
► A MPC strategy was developed and compared with the PID control strategy.
► MPC proved to be more efficiently for the refinery heat integrated processes.