title: Influence of different substrates on the performance of a two-stage high pressure anaerobic digestion system.
abstract: The two-stage autogenerative high-pressure digestion technique is a novel and promising approach for the production of gaseous fuels or upgraded biogas. This new technique is described in the patent DE 10 2011 015415 A1 and integrates biogas production, its upgrading and pressure boosting in one process. Anaerobic digestion under elevated pressure conditions leads to decreasing pH-values in the digestate due to the augmented formation of carboxylic acid. Model calculations carried out to evaluate the two-stage design showed that the pH-value in the pressurized anaerobic filter has a major influence on the methane content of the biogas produced. Within this study, the influence of the nitrogen content as one of the most important buffering substances on the performance of the system has been tested. The results show that higher NH4 contents lead to higher pH-values in the digester and as a consequence to higher methane contents.
authors.affiliation: State Institute of Agricultural Engineering and Bioenergy, University of Hohenheim, Garbenstraße 9, D-70599 Stuttgart, Germany. Electronic address: Andreas.Lemmer@uni-hohenheim.de.
authors.forename: A
authors.initials: A
authors.lastname: Lemmer
authors.affiliation: State Institute of Agricultural Engineering and Bioenergy, University of Hohenheim, Garbenstraße 9, D-70599 Stuttgart, Germany.
authors.forename: Y
authors.initials: Y
authors.lastname: Chen
authors.affiliation: State Institute of Agricultural Engineering and Bioenergy, University of Hohenheim, Garbenstraße 9, D-70599 Stuttgart, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Lindner
authors.affiliation: DVGW - Research Center at the Engler-Bunte-Institut, Karlsruhe Institute of Technology (KIT), Engler-Bunte-Ring 1, D-76131 Karlsruhe, Germany.
authors.forename: A M
authors.initials: AM
authors.lastname: Wonneberger
authors.affiliation: State Institute of Agricultural Engineering and Bioenergy, University of Hohenheim, Garbenstraße 9, D-70599 Stuttgart, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Zielonka
authors.affiliation: State Institute of Agricultural Engineering and Bioenergy, University of Hohenheim, Garbenstraße 9, D-70599 Stuttgart, Germany.
authors.forename: H
authors.initials: H
authors.lastname: Oechsner
authors.affiliation: State Institute of Agricultural Engineering and Bioenergy, University of Hohenheim, Garbenstraße 9, D-70599 Stuttgart, Germany.
authors.forename: T
authors.initials: T
authors.lastname: Jungbluth
mesh_terms: D000693:Anaerobiosis; D056804:Biofuels; D057919:Biological Oxygen Demand Analysis; D005285:Fermentation; D006863:Hydrogen-Ion Concentration; D008697:Methane / Q000096:biosynthesis; D011312:Pressure; D012037:Refuse Disposal / Q000379:methods*; D014865:Waste Disposal, Fluid
chemical_list: D056804:Biofuels; D008697:Methane
keywords: Anaerobic digestion; Biogas; High pressure digestion; Two-stage; Upgrading