Comparative Study of PID Controllers for Time-Varying of Steam Distillation Process

The steam distillation technique is the earliest technique to extract the essential oil from botanical raw material. Until today, the technique are still relevant and popular among the industrial practitioners due to low manufacturing cost, green environment and higher yield produced. In order to extract the oils, the botanical raw material placed inside the distillation tank which is above the water level. The steam are produced by boiling the water inside the distillation tank. Then, the botanical raw material is heated by the steam and breaking the gland. In order to produce the best quality of essential oils, the con-trolling of steam temperature is important. The disclosure of extracted raw material to the high degree of steam temperature is expose to risk which degradation of essential oils produced. To ensure the process is able to produce the high quality of essential oils; the process dynamic must be regulated by capable controller. In addition, the controller also need to have capability to capture and control dynamic behavior of the system. In this studies, the Small-Medium Scale Steam Distillation System is developed and controlled by PID controller to regulate the temperature at desired setpoint. The development of PID are tuned by the Cohen-Coon, Chchen-Reswicks and Hrones and AMIGO which the controller performance are evaluated based on step test, set point change test and error matrices.