Anaerobic digestion of whole stillage from dry-grind corn ethanol plant under mesophilic and thermophilic conditions.
Anaerobic digestion of whole stillage from a dry-grind corn-based ethanol plant was evaluated by batch and continuous-flow digesters under thermophilic and mesophilic conditions. At whole corn stillage concentrations of 6348 to 50,786 mg total chemical oxygen demand (TCOD)/L, at standard temperature (0 °C) and pressure (1 atm), preliminary biochemical methane potential assays produced 88±8 L (49±5 L CH4) and 96±19 L (65±14 L CH4) biogas per L stillage from mesophilic and thermophilic digesters, respectively. Continuous-flow studies for the full-strength stillage (TCOD=254 g/L) at organic loadings of 4.25, 6.30 and 9.05 g TCOD/L days indicated unstable performance for the thermophilic digester. Among the sludge retention times (SRTs) of 60, 45 and 30 days tested, the mesophilic digestion was successful only at 60 days-SRT which does not represent a practical operation time for a large scale bioethanol plant. Future laboratory studies will focus on different reactor configurations to reduce the SRT needed in the digesters.
Eskicioglu
Cigdem
C
Department of Civil Engineering, University of Ottawa, Ottawa, ON, Canada K1N 6N5. cigdem.eskicioglu@ubc.ca
Kennedy
Kevin J
KJ
Marin
Juan
J
Strehler
Benjamin
B
D000693:Anaerobiosis; D001419:Bacteria / Q000378:metabolism*; D056804:Biofuels / Q000032:analysis*; D001709:Biotechnology / Q000379:methods*; D003890:Desiccation; D000431:Ethanol / Q000032:analysis*; D005232:Fatty Acids, Volatile / Q000032:analysis; D008697:Methane / Q000032:analysis; D009930:Organic Chemicals / Q000032:analysis; D013696:Temperature; D013997:Time Factors; D014866:Waste Products; D003313:Zea mays / Q000378:metabolism*
D056804:Biofuels; D005232:Fatty Acids, Volatile; D009930:Organic Chemicals; D014866:Waste Products; D000431:Ethanol; D008697:Methane