Biogas production from brewery spent grain as a mono-substrate in a two-stage process composed of solid-state anaerobic digestion and granular biomass reactors
Anaerobic digestion of brewery spent grain as a mono-substrate was studied. Brewery spent grain is a substrate consisting largely of cellulose, hemicellulose and lignin, which are difficult to degrade anaerobically, mostly due to the presence of degradation products, such as phenolic compounds, which cause process inhibition. Therefore, a two-stage system was used for anaerobic digestion. Anaerobic digestion was phase separated in a solid-state anaerobic digestion reactor, where microbiological hydrolysis and acidogenesis occurred and in a granular biomass reactor where mostly methanogenesis was performed. The overall process exhibited total solids degradation efficiency between 75.9 and 83.0 %. Average specific biogas production was 414±32 L/kg, whereas biomethane production was 224±34 L/kg of added total solids. Granular biomass after adaptation exhibited stable operation at substrate C/N ratios in range 0.16 – 4.68. p-cresol was present in concentrations up to 45 mg/L and during the process was successfully degraded by granular biomass. The excellent adaptability of granular biomass was confirmed by 68.2 % shift in bacterial and a 31.8 % shift in archaeal community structure in a granular biomass reactor. The structure of the bacterial community from granular biomass reactor and solid-state anaerobic digestion reactor remained 79.4 % similar at the end of the experiment, whereas archaeal community was only 31.6 % similar. The process exhibited stable operation for 198 days, which shows that brewery spent grain can be successfully anaerobically digested and used for biogas production.
2017
2017-08-17 23:32:22
1033
biogas production, brewery spent grain, C/N ratio, dry digestion, microbial biomass, solid-state anaerobic digestion
r6
Mario
Panjicko
70
Gregor Drago
Zupančič
70
Romana
Marinšek-Logar
70
Lijana
Fanedl
70
Marina
Tišma
70
Bruno
Zelić
70
COBISS_ID
3
4876283
NUK URN
18
URN:SI:UNG:REP:9UPAN9YW
Biogas_production_from_brewery_spent_grain_as_a_mono-substrate..._-_Panjicko_et_al..pdf
2376335
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2017-08-17 23:33:31