Antonio Felype Ferreira Maciel 
, Otacilio Bezerra Leite Neto , Michela Mulas & Hamse Kjerstadius
Abstract: This work investigates the model calibration, state estimation, and control of an Up-flow Anaerobic Sludge Blanket (UASB) reactor for the task of increasing its biogas production while complying with effluent quality requirements. We consider a dynamic model based on the Anaerobic Digestion Model No. 1 (ADM1), calibrated using experimental data from a blackwater treatment plant located in Helsingborg, Sweden. Using this model, we design a control solution composed of an operating point optimiser, defining the setpoints that achieve maximum biogas production, and a feedback controller, that tracks these setpoints while rejecting disturbances. For the feedback controller, we consider two alternative approaches: a multiloop Proportional-Integral-Derivate (PID) controller and an output-feedback Model Predictive Controller (MPC). The control solution is showcased on simulated experiments of operating the UASB reactor under different influent disturbance scenarios and compared with the nominal open-loop operation. Our results show that the controlled system is able to increase biogas production, while also improving effluent quality. Both control approaches have similar setpoint tracking performances, with the MPC being more economical and robust to influent disturbances.
Keywords: UASB, System Identification, Feedback Control, State Estimation, Wastewater Treatment, Biogas.
DOI code: 10.21528/lnlm-vol24-no1-art4
PDF file: vol24-no1-art4.pdf
BibTex file: vol24-no1-art4.bib