Temperature control of a non-isothermal CSTR at the unstable region using PID mode

• Main Authors: Go, Jonathan, Gobaco, Mario, Ha, Christopher
• Format: text
• Language: English
• Published: Animo Repository 1995
• Subjects: Temperature control; Tanks; Chemical processes; Chemical reactions; Chemical Engineering
• Online Access: https://animorepository.dlsu.edu.ph/etd_bachelors/9284
• Institution: De La Salle University

This study aim isto test the control of a continuous stirred-tank reactor (CSTR) using PID mode of control with suppressed over-shooting feature at the unstable region of the multiple steady-state behavior exhibited by the test reactants, sodium thiosulfate and hydrogen peroxide. The experimentation includes the verification, by actual testing, the multiple steady-state behavior exhibited by the laboratory-scale CSTR.Experimental data were obtained by taking samples from the CSTR at every steady-state operating point or controlled region in order to determine the conversion at that point. Temperature readings at important spots such as the inlet and outlet were also taken. These values were then plotted to determine the regions of steady and unsteady-state. Control of the reactor at the unsteady-state temperature was effected by admitting cooling water into the jacket surrounding the CSTR to remove any excess heat of reaction that will cause a rise in reaction temperature. The flow rate of the cooling water was varied with the use of a proportional valve which is driven by an electronic actuator. This actuator was regulated by the PID controller to which it was connected.The action of the controller was such that the reactor temperature will not exceed the set point but will approach it from time to time. Results showed that an S-shaped curve could be obtained when data for temperature rise is plotted against residence time. The unsteady-state temperature was taken from the sum of the midpoint of that S-curve and the average inlet temperature. The PID controller was able to control the temperature with +2 and -3 centigrade deviations from the set point. It was also able to control the temperature at the set point for a maximum of 18 minutes and 16.93 seconds.