Input-output Linearizing Control of Strong Acid-base Neutralization Process with Fluctuation in Feed pH

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Published: Oct 15, 2020
Keywords:
pH Neutralization Model-based control I/O linearization pH Feed Fluctuation

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Thana Srihawan
Department of Chemical Engineering, Center of Excellence on Petrochemicals and Materials Technology, Faculty of Engineering, Kasetsart University, Bangkok, Thailand
Chanin Panjapornpon
Department of Chemical Engineering, Center of Excellence on Petrochemicals and Materials Technology, Faculty of Engineering, Kasetsart University, Bangkok, Thailand

Abstract

This work presents a control system design for coupled control of pH and level with fluctuation in influent pH by manipulating influent and acid flow rates. A mathematical model based on the difference between proton and hydroxide ions estimated by the measured pH is introduced and applied in a formulation of the model-based control system. A feedback controller and estimated state disturbance are obtained by solving a minimization problem of squared errors between requesting input-output linearizing output responses and the reference setpoints. To eliminate the offset response, the estimated disturbance is applied in the calculation of the closed-loop compensator. The performance of the developed control system is evaluated in a bench-scale pH neutralization process of HCl-NaOH system, and it is also compared to that of a proportional-integral controller. The results show that the developed controllers could enforce a system with fluctuation in influent pH to the desired setpoints effectively, while the PI controller gave oscillation in outputs around the setpoints and cannot achieve the desired targets.

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How to Cite
Srihawan, T., & Panjapornpon, C. (2020). Input-output Linearizing Control of Strong Acid-base Neutralization Process with Fluctuation in Feed pH. Applied Science and Engineering Progress, 13(4), 327–335. Retrieved from https://ph02.tci-thaijo.org/index.php/ijast/article/view/242289
Issue
Vol. 13 No. 4 (2020)
Section
Research Articles

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