Active Disturbance Rejection Control of a methanol-water separation distillation column

ADRC has been shown capable of overcoming the limitations of conventional PID controller in dealing with setpoint jump, noise sensitivity because of derivative term, simplicity of the linear weighted sum of three terms (current error, past error and the rate of change), and the integral term. However, applications of ADRC in the chemical process control area are relative few, especially in the control of multi-input and multi-output nonlinear chemical processes. This paper presents using ADRC to control the top and bottom product compositions of a methanol-water separation distillation column, which is simulated using a rigorous nonlinear tray by tray mechanistic model. It is shown that ADRC gives much improved control performance compared to PID control.