Control of ideal heat integrated distillation columns

The operation of an ideal heat integrated distillation column (HIDiC) is ad dressed. Five kinds of control configurations, i.e. single-loop control, mu lti-loop control, multivariable internal model control (IMC), modified mult ivariable internal model control (MIMC) and nonlinear process model-based c ontrol (NPMC), are designed and applied to the process. Simulation results demonstrate that all of the above control configurations are valid for prod uct quality control. NPMC control configuration is found to be the best one among all the alternatives. It can readily realize setpoint transitions an d conduct effectively against external disturbances. MIMC control configura tion ranks second in the row for its regulatory responses to feed compositi on disturbances with relatively extended setting time. Next comes from the multi-loop control configuration, which is more or less handicapped by its greater deviations and overshootings. IMC control configuration can not com pete with the multi-loop control configuration because it is extremely sens itive to operating condition changes. Single-loop control configuration is the worst one among all the mentioned control configurations. Its responses for the uncontrolled end products are extremely sluggish.