Integration of pyrolysis and anaerobic digestion--use of aqueous liquor from digestate pyrolysis for biogas production.
Anaerobic digestion of aqueous pyrolysis liquor derived from pyrolysis of solid digestate was tested in batch mode using an un-adapted inoculum. Three pyrolysis liquors produced at 330°C, 430°C and 530°C in four COD-based concentrations of 3, 6, 12 and 30 g L(-1) were investigated. The three lower concentrations showed considerable biogas production, whereas the 30 g L(-1) dosage caused process inhibition. The highest methane yield of 199.1±18.5 mL g(COD)(-1) (COD removal: 56.9±5.3%) was observed for the 330°C pyrolysis liquor, followed by the 430°C sample with only slightly lower values. The 530°C sample dropped to a yield of 129.3±19.7 mL g(COD)(-1) (COD removal: 36.9±5.6%). Most VOCs contained in the pyrolysis liquor (i.e. furfural, phenol, catechol, guaiacol, and levoglucosan) were reduced below detection limit (cresol by 10-60%). Consequently, integrated pyrolysis and anaerobic digestion in addition to thermochemical conversion of digestate also promises bioconversion of pyrolysis liquors.
Leibniz Institute for Agricultural Engineering Potsdam-Bornim, Max-Eyth-Allee 100, 14469 Potsdam, Germany.
Tobias
T
Hübner
Leibniz Institute for Agricultural Engineering Potsdam-Bornim, Max-Eyth-Allee 100, 14469 Potsdam, Germany; UK Biochar Center, School of GeoSciences, University of Edinburgh, Crew Building, King's Building, Edinburgh EH9 3JN, UK. Electronic address: jmumme@atb-potsdam.de.
Jan
J
Mumme
D000693:Anaerobiosis; D056804:Biofuels; D057919:Biological Oxygen Demand Analysis; D001709:Biotechnology / Q000379:methods*; D003408:Cresols / Q000302:isolation & purification; D005285:Fermentation; D006863:Hydrogen-Ion Concentration; D008697:Methane / Q000096:biosynthesis; D008962:Models, Theoretical; D013696:Temperature; D014865:Waste Disposal, Fluid
D056804:Biofuels; D003408:Cresols; D008697:Methane
Anaerobic digestion; Biocrude; Detoxification; Process integration; Pyrolysis