TY - JOUR
T1 - Stick or leave - Pushing methanogens to biofilm formation for ex situ biomethanation
AU - Jensen, Mads Borgbjerg
AU - Strübing, Dietmar
AU - de Jonge, Nadieh
AU - Nielsen, Jeppe Lund
AU - Ottosen, Lars Ditlev Mørck
AU - Koch, Konrad
AU - Kofoed, Michael Vedel Wegener
N1 - Copyright © 2019. Published by Elsevier Ltd.
PY - 2019/11
Y1 - 2019/11
N2 - Biomethanation exploits the ability of methanogenic archaea to convert CO2 and renewable H2 from electrolysis to biomethane. Biofilm reactors are promising for biomethanation scale-up due to high CH4 productivity and low energy input for H2 gas-liquid mass transfer. Effects of operational conditions on biofilm dynamics remain largely uncharacterized but may increase reactor potentials further. This study investigated the effect of hydraulic retention time (HRT) on methanogenic biofilm activity and composition. Commercial carriers floating in liquid were exposed to H2/CO2 for 87 days with the liquid phase being subject to either 18 hours, 10 days, or 20 days HRT. Methanogenic biofilms were dominated by hydrogenotrophic methanogens, but biofilm CH4 productivity was enhanced at 18 hours HRT due to wash-out of competing planktonic species, which otherwise hampered proliferation of biofilm biomass at long HRT. It is suggested that high-rate biofilm reactors can increase methanogenic biofilm activity by minimizing the liquid's H2 exposure.
AB - Biomethanation exploits the ability of methanogenic archaea to convert CO2 and renewable H2 from electrolysis to biomethane. Biofilm reactors are promising for biomethanation scale-up due to high CH4 productivity and low energy input for H2 gas-liquid mass transfer. Effects of operational conditions on biofilm dynamics remain largely uncharacterized but may increase reactor potentials further. This study investigated the effect of hydraulic retention time (HRT) on methanogenic biofilm activity and composition. Commercial carriers floating in liquid were exposed to H2/CO2 for 87 days with the liquid phase being subject to either 18 hours, 10 days, or 20 days HRT. Methanogenic biofilms were dominated by hydrogenotrophic methanogens, but biofilm CH4 productivity was enhanced at 18 hours HRT due to wash-out of competing planktonic species, which otherwise hampered proliferation of biofilm biomass at long HRT. It is suggested that high-rate biofilm reactors can increase methanogenic biofilm activity by minimizing the liquid's H2 exposure.
KW - Ex situ biomethanation
KW - H
KW - Homoacetogenesis
KW - Hydraulic retention time
KW - Methanogenic biofilm
KW - Methane/metabolism
KW - Biofilms
KW - Bioreactors
KW - Plankton/metabolism
KW - Biomass
KW - Euryarchaeota/physiology
UR - http://www.scopus.com/inward/record.url?scp=85069726595&partnerID=8YFLogxK
U2 - 10.1016/j.biortech.2019.121784
DO - 10.1016/j.biortech.2019.121784
M3 - Journal article
C2 - 31344638
SN - 0960-8524
VL - 291
JO - Bioresource Technology
JF - Bioresource Technology
M1 - 121784
ER -