Predictive control of anaerobic digestion of wastewater sludge. A feasibility study

This paper presents the analysis, modeling, identification and predictive control of an anaerobic digestion process. The widely adopted anaerobic digestion model ADM1 is used to describe the anaerobic digestion of primary and secondary wastewater sludge. Their feed flow rates constitute two model inputs, which are considered as manipulated variables, while the biogas production rate and its methane content constitute two model outputs (controlled variables). The general control objective is to manipulate the inputs within the operation limits such that a maximum methane production is ensured at all times. A comparison between open-loop and closed-loop control reveals the net advantage of predictive control for optimal rate regulation.