Selection of control structure and dual composition control for ethanol-water distillation column

Distillation is one of the important separation processes in the chemical and petrochemical Industry. Saving the potential energy and maintaining the purity of the product can be achieved by implementing better control strategy. The choice of an efficient control configuration by using relative gain array for assessing control loop interactions is used in evaluating the efficiency of various control structures. The regulatory level dual composition control is demonstrated on a binary distillation column: ethanol-water separation for three configurations namely LB, LV and DV configurations. This paper also presents the design of decentralized controller based on BLT tuning method which is also extended to design centralized controller. The results of decentralized control scheme as well as centralized control scheme have been compared and presented. Steady state and Dynamic simulation of distillation column were carried out using ASPEN software package.