Model-based optimal recovery of methane production in an anaerobic digestion reactor

Abstract

An unhealthy condition of a biogas reactor is an abnormal situation characterized by a large reduction of the concentration of the microorganisms in the reactor, causing a reduction of the biogas production. This condition may occur due to too high feeding rate to the reactor. If an unhealthy condition continues for several days, the reactor may get into a washout situation where the methane production may drop considerably. By monitoring the alkalinity ratio or the methane production rate, an unhealthy condition can be recognized. Threshold of the alkalinity ratio or the methane production volume level can be determined by users for the start of applying the optimal recovery procedure. The goal of this study is an investigation on optimal recovery of methane production after determining an unhealthy condition. Our approach is model-based optimization, applied to a simulated reactor. The AM2 model is assumed.

Keywords

• anaerobic digestion
• mathematical model
• optimal methane recovery
• optimization
• simulation