Hydrogen and methane production in a two-stage anaerobic digestion system by co-digestion of food waste, sewage sludge and glycerol
- Civil Engineering Program, COPPE, Federal University of Rio de Janeiro, Rio de Janeiro, RJ (Brazil)
- Energy Research Company (EPE), Rio de Janeiro, RJ (Brazil)
Highlights: • H{sub 2} and CH{sub 4} production was assessed in a two-stage acidogenesis-methanogenesis system. • Addition of glycerol to food waste and sewage sludge increased H{sub 2} and CH{sub 4} yields. • Stable H{sub 2} and CH{sub 4} production and higher energy yield were obtained at 1% glycerol. • The use of 3% glycerol led to process instabilities in the methanogenic phase. • Co-digestion of food waste, sewage sludge and glycerol maximizes energy production. - Abstract: In this study, hydrogen and methane production from co-digestion of food waste (FW), sewage sludge (SS) and raw glycerol (GL) was evaluated in a two-stage acidogenesis-methanogenesis anaerobic system under mesophilic conditions (35 °C). The effect of glycerol addition (1 and 3% v/v) as co-substrate was assessed in ternary mixtures (FW + SS + GL), with the concentration of all substrates kept at 10 g VS/L. Besides contributing to reduce the lag phase of the acidogenic bacterial culture, the presence of GL increased the hydrogen production in all tested conditions and the maximum hydrogen yield was obtained for the FW + SS + 3%GL mixture (179.3 mL H{sub 2}/g VS). On the other hand, the highest methane production (342 mL CH{sub 4}/g VS) was achieved in the test supplemented with 1% GL. At 3% GL, abrupt reductions in the biogas CH{sub 4} content and pH values resulting from instability in methanogenesis process were noticed over the experiment. By taking into account the hydrogen and methane production stages, the highest energy yield (i.e., 15.5 kJ/g VS) was obtained with the ternary mixture containing 1% GL. Overall, the results of this study demonstrate the feasibility of using glycerol as co-substrate to increase the H{sub 2} and CH{sub 4} production efficiency in a two-stage anaerobic co-digestion process, allowing simultaneous treatment of three residues (FW, SS and GL) and energy production.
- OSTI ID:
- 22841180
- Journal Information:
- Waste Management, Vol. 76; Other Information: Copyright (c) 2017 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); ISSN 0956-053X
- Country of Publication:
- United States
- Language:
- English
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