Optimization of catalyst service cycle and start-up considering the reactor-distillation-HEN integration and climate

Abstract

Considering the catalyst deactivation and seasonal temperature variation, a systematic method is proposed for clarifying the dynamic variation of system operating parameters and targeting the optimal catalyst regeneration cycle and start-up date. Relationships between catalyst activity, reactor inlet and outlet temperatures, reactor heat load, and running time are deduced, as well as that between column temperatures, pressures, energy demands, processing capacity, and production month. Diagrams are constructed to illustrate the parameter variations. With the energy consumption and processing capacity combined, an evaluation index is introduced for integrating the reactor-separator-heat exchanger network (HEN) and optimizing the production start-up date. The proposed method is intuitive and efficient and can be used for system design, guiding production, or fault diagnosis. A benzene alkylation process is studied; the optimal regeneration cycle of the ZSM-5 catalyst is 11 months, and the best start-up date is August, saving 2.32 × 10⁵ kgce (kg standard coal) per production cycle.