Mathematical modelling of in-situ microaerobic desulfurization of biogas from sewage sludge digestion

Abstract

Microaeration can be used to cost-effectively remove in-situ H2S from the biogas generated in anaerobic digesters. This study is aimed at developing and validating an extension of the Anaerobic Digestion Model n°1 capable of incorporating the main phenomena which occurs during microaeration. This innovative model was implemented and tested with data from a pilot scale digester microaerated for ∼ 200 d. The results showed that despite the model’s initial ability to predict the digester’s behavior, its predicted performance was improved by calibrating the most influential parameters. The model’s prediction potential was largely enhanced by adding retention parameters that account for the activity of sulfide oxidizing bacteria retained inside the anaerobic digester, which have been consistently shown to be responsible for a large share of the H2S removed. Keywords: Biogasin-situdesulfurization, H2S, Modeling, Simulation