Robust methane production from anaerobic digestion of maize silage: Feeding control using sliding mode control strategy with Anaerobic Digestion Model N°01

This paper introduces a robust control approach based on the Sliding Mode Control (SMC) strategy for the Anaerobic Digestion (AD) process. The Anaerobic Digestion Model N°1 (ADM1), the most detailed and comprehensive model in this field, is used as a virtual AD plant. The proposed control scheme is derived from a reduced model. This control law utilizes the state variables of the reduced AM2HN model along with the stoichiometric and kinetic parameters. An interface block between the ADM1 and AM2HN state variables has been designed in a closed-loop configuration. The performance of SMC has been enhanced through the use of a low-pass filter, which completely eliminates chattering, providing smooth, chatter-free dilution rates while preserving the rapid convergence to target methane production (within less than 5 days) even in a noisy environment.