Decoupling control of high-purity heat integrated distillation column process via active disturbance rejection control and nonlinear wave theory

Although the heat integrated distillation is an energy-efficient and environment-friendly separation technology, it has not been commercialized. One of the reasons is that the nonlinear dynamics and the interactions between various control loops have limited the performance of the traditional control strategy. To achieve a high-purity product concentration, a dynamic decoupling control strategy based on active disturbance rejection control (ADRC) is proposed. The effects of interactions, uncertainties and external disturbances can be estimated and rejected by using extended state observer. Considering the constraints on manipulated variables, an optimized ADRC is designed for the first-order system. Moreover, a concentration observer based on a nonlinear wave model is formulated to reduce the number of sensors. In the simulation research, the related internal model control (IMC), multi-loop ADRC and model predictive control (MPC) are compared with the proposed control scheme. The simulation results demonstrate the advantages of the proposed control scheme on tight control, decoupling performance and disturbance rejection for the high-purity heat integrated distillation column.