Foam suppression in overloaded manure-based biogas reactors using antifoaming agents

• Published in: Bioresource technology Vol. 153; pp. 198 - 205
• Main Authors: Kougias, P.G., Boe, K., Tsapekos, P., Angelidaki, I.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01-02-2014; Elsevier
• Subjects: Anaerobic digestion; Animals; Antifoaming Agents - pharmacology; Antifoams; Applied sciences; Batch Cell Culture Techniques; Biofuel production; Biofuels; Biogas; Biological and medical sciences; Biological treatment of sewage sludges and wastes; Bioreactors; Biotechnology; Cattle; Dosage; Energy; Environment and pollution; Exact sciences and technology; Fatty Acids, Volatile - analysis; Foaming; Foams; Fundamental and applied biological sciences. Psychology; Hydrogen-Ion Concentration - drug effects; Industrial applications and implications. Economical aspects; Manure; Methane; Methane - analysis; Methods. Procedures. Technologies; Octanoic acid; Organic overload; Pollution; Rapeseed oil; Reactors; Various methods and equipments; Wastes; Organic overload; Biogas; Foaming; Anaerobic digestion; Antifoams; Organic waste; Bioreactor; Foam; Overload
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2013.11.083

•Rapeseed oil, oleic and octanoic efficiently suppressed foaming in biogas reactors.•Rapeseed oil was the most suitable antifoam for overloaded reactors.•Rapeseed oil showed synergistic effect on methane yield when digested with manure.•Tributylphosphate inhibited severely the anaerobic digestion process.
Foam control is an imperative need in biogas plants, as foaming is a major operational problem. In the present study, the effect of oils (rapeseed oil, oleic acid, and octanoic acid) and tributylphosphate on foam reduction and process performance in batch and continuous manure-based biogas reactors was investigated. The compounds were tested in dosages of 0.05%, 0.1% and 0.5% v/vfeed. The results showed that rapeseed oil was most efficient to suppress foam at the dosage of 0.05% and 0.1% v/vfeed, while octanoic acid was most efficient to suppress foam at dosage of 0.5% v/vfeed. Moreover, the addition of rapeseed oil also increased methane yield. In contrast, tributylphosphate, which was very efficient antifoam, was found to be inhibitory to the biogas process.