Control and estimation of anaerobic digestion processes using hydrogen and volatile fatty acids measurements

The anaerobic digestion (AD) technology is widely used in the treatment of waste and wastewater. To ensure the treatment efficiency and to increase the production of biogas, which can be reused as a renewable energy source, the process and tight control are needed. An estimation and control scheme, which can be successfully used in the operationof the AD process, were developed. The process is simulated by the ADM1 model, the most complex and detailed model developed so far to characterize AD. The controller and the observer, which provides estimates of the unmeasurable variables needed in the computation of the control law, are designed based on a simplified model developed in a previous work. Since it has been shown that hydrogen concentration is an accurate and fast indicator of process stability, it was chosen as controlled variable. Simulation results prove the effectiveness of the proposed control structure.