Decentralized temperature control of a pilot dividing wall column

The technology of dividing wall columns offers to save high amounts of operating and investment cost compared to conventional distillation columns and their configurations. The practical application is still limited due to a lack of experience and high interactions among the process variables.The present work deals with the development and test of a control system for a pilot dividing wall column. Within this, decentralized temperature control systems are designed by a systematic approach. Furthermore, these systems are evaluated concerning the process stability, the providing of defined product purities and the respective requirement of energy in case of disturbances. The focus is on simulative and experimental investigations in order to assure the practicability of the developments. The presented results show the effectiveness of the applied methods.

Research highlights▶ A systematic physically based procedure for the generation of decentralized temperature control structures for dividing wall columns is developed. The approach is transferable to other applications. ▶ The approach considers the important aspect of energy optimal operation. Referring to this it is necessary to define an additional controlled variable and include the liquid split ratio above the dividing wall in the control system. ▶ The approach is based on a rigorous mathematical model. ▶ The effectiveness is proven with the help of real experiments.