title: Influence of pressures up to 50bar on two-stage anaerobic digestion.
abstract: The concept of pressurized two-stage anaerobic digestion integrates biogas production, purification and pressure boosting within one process. The produced methane-rich biogas can be fed into gas grids with considerably less purification effort. To investigate biogas production under high pressures up to 50bar, a lab scale two-stage anaerobic digestion system was constructed including one continuously operated pressurized methane reactor. This investigation examined the effects of different operating pressures in methane reactor (10, 25, 50bar) on biogas quantity and quality, pH value and process stability. By increasing operating pressures in methane reactor, the pH value decreased from 6.65 at 10bar to 6.55 at 50bar. Simultaneously, methane content increased from 79.08% at 10bar to 90.45% at 50bar. The results show that methane reactors can be operated up to 50bar pressure continuously representing a viable alternative to commonly used gas upgrading methods because of reduced purification effort.
authors.affiliation: University of Hohenheim, State Institute of Agricultural Engineering and Bioenergy, Garbenstrasse 9, 70599 Stuttgart, Germany. Electronic address: wolfgang.merkle@uni-hohenheim.de.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Merkle
authors.affiliation: DVGW - Research Center at the Engler-Bunte-Institute, Karlsruhe Institute of Technology (KIT), Engler-Bunte-Ring 1, 76131 Karlsruhe, Germany.
authors.forename: Katharina
authors.initials: K
authors.lastname: Baer
authors.affiliation: University of Hohenheim, State Institute of Agricultural Engineering and Bioenergy, Garbenstrasse 9, 70599 Stuttgart, Germany.
authors.forename: Jonas
authors.initials: J
authors.lastname: Lindner
authors.affiliation: University of Hohenheim, State Institute of Agricultural Engineering and Bioenergy, Garbenstrasse 9, 70599 Stuttgart, Germany.
authors.forename: Simon
authors.initials: S
authors.lastname: Zielonka
authors.affiliation: DVGW - Research Center at the Engler-Bunte-Institute, Karlsruhe Institute of Technology (KIT), Engler-Bunte-Ring 1, 76131 Karlsruhe, Germany.
authors.forename: Felix
authors.initials: F
authors.lastname: Ortloff
authors.affiliation: DVGW - Research Center at the Engler-Bunte-Institute, Karlsruhe Institute of Technology (KIT), Engler-Bunte-Ring 1, 76131 Karlsruhe, Germany.
authors.forename: Frank
authors.initials: F
authors.lastname: Graf
authors.affiliation: DVGW - Research Center at the Engler-Bunte-Institute, Karlsruhe Institute of Technology (KIT), Engler-Bunte-Ring 1, 76131 Karlsruhe, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Kolb
authors.affiliation: University of Hohenheim, State Institute of Agricultural Engineering and Bioenergy, Garbenstrasse 9, 70599 Stuttgart, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Jungbluth
authors.affiliation: University of Hohenheim, State Institute of Agricultural Engineering and Bioenergy, Garbenstrasse 9, 70599 Stuttgart, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Lemmer
mesh_terms: D000693:Anaerobiosis; D056804:Biofuels / Q000032:analysis; D057919:Biological Oxygen Demand Analysis; D019149:Bioreactors; D001709:Biotechnology / Q000379:methods*; D002245:Carbon Dioxide / Q000032:analysis; D006863:Hydrogen-Ion Concentration; D008697:Methane / Q000096:biosynthesis; D011312:Pressure
chemical_list: D056804:Biofuels; D002245:Carbon Dioxide; D008697:Methane
keywords: Anaerobic digestion; Biogas; Biomethane; High pressure; Two-stage