Sahel Javahernia - Electrical Engineering Department,Sofyan Branch,Islamic Azad University,IRAN
Fatemeh Masoudinia - Electrical Engineering Department,Sofyan Branch,Islamic Azad University,IRAN

In this research, an alternative control method based on Fuzzy Inference System (FIS) is proposed to keepthe product composition of a distillation column constant. This study compares a proposed FIS withtraditional PID (proportional, integral, derivative) control technique and analyzes the results. The FIS isapplied to the control of the tray temperature of the distillation column by using indirect feed split controlstructure to modulate the steam flow with management of the tray temperature. In turn, this modulationmaintains the composition of product at specified levels. Rockwell fuzzy designer is used to develop thefuzzy logic controller. Both a fuzzy logic controller and a PID controller are downloaded in the RockwellControl Logix L26 process controller. Chemstations Chemcad simulation software is used to run thedistillation column simulations. Simulation results are programmed into L26 process controller to behaveas a dynamic distillation column. Results show that the proposed fuzzy logic controller is more tolerant todisturbances in the feed flow and feed composition of the distillation column than the PID controller.

Fuzzy Logic, Controller, Distillation Column, Rockwell Software