High-pressure anaerobic digestion up to 100 bar: influence of initial pressure on production kinetics and specific methane yields

• Published in: Environmental technology Vol. 38; no. 3; pp. 337 - 344
• Main Authors: Merkle, Wolfgang, Baer, Katharina, Haag, Nicola Leonard, Zielonka, Simon, Ortloff, Felix, Graf, Frank, Lemmer, Andreas
• Format: Journal Article
• Language: English; French
• Published: England Taylor & Francis 01.02.2017; Taylor & Francis Ltd
• Subjects: Anaerobic digestion; Anaerobiosis; Biogas; Bioreactors; compressibility factor; Gas production; Gases; Gompertz equation; High pressure; Hydrolysates; Initial pressure; Kinetics; Methane; Methane - metabolism; Microorganisms; Oil and gas production; Organic acids; Poaceae; Pressure; Rare gases; Reactors; Refuse as fuel; Silage; two-stage anaerobic digestion; Zea mays; Gompertz equation; two-stage anaerobic digestion; compressibility factor; biogas; High pressure
• ISSN: 0959-3330; 1479-487X
• DOI: 10.1080/09593330.2016.1192691

To ensure an efficient use of biogas produced by anaerobic digestion, in some cases it would be advisable to upgrade the biogenic gases and inject them into the transnational gas grids. To investigate biogas production under high-pressure conditions up to 100 bar, new pressure batch methane reactors were developed for preliminary lab-scale experiments with a mixture of grass and maize silage hydrolysate. During this investigation, the effects of different initial pressures (1, 50 and 100 bar) on pressure increase, gas production and the specific methane yield using nitrogen as inert gas were determined. Based on the experimental findings increasing initial pressures alter neither significantly, further pressure increases nor pressure increase rates. All supplied organic acids were degraded and no measurable inhibition of the microorganisms was observed. The results show that methane reactors can be operated at operating pressures up to 100 bar without any negative effects on methane production.