Combining biocatalyzed electrolysis with anaerobic digestion

Biocatalyzed electrolysis is a microbial fuel cell based technology for the generation of hydrogen gas and other reduced products out of electron donors. Examples of electron donors are acetate and wastewater. An external power supply can support the process and therefore circumvent thermodynamical constraints that normally render the generation of compounds such as hydrogen unlikely. We have investigated the possibility of biocatalyzed electrolysis for the generation of methane. The cathodically produced hydrogen could be converted into methane at a ratio of 0.41 mole methane mole−1 acetate, at temperatures of 22±2°C. The anodic oxidation of acetate was not hampered by ammonium concentrations up to 5 g N L−1.An overview is given of potential applications for biocatalyzed electrolysis.

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Lack of Electricity Production by Pelobacter carbinolicus Indicates that the Capacity for Fe(III) Oxide Reduction Does Not Necessarily Confer Electron Transfer Ability to Fuel Cell Anodes

Applied and Environmental Microbiology ◽

10.1128/aem.00804-07 ◽

2007 ◽

Vol 73 (16) ◽

pp. 5347-5353 ◽

Cited By ~ 93

Author(s):

Hanno Richter ◽

Martin Lanthier ◽

Kelly P. Nevin ◽

Derek R. Lovley

Keyword(s):

Electron Transfer ◽

Fuel Cells ◽

Fuel Cell ◽

Microbial Fuel Cell ◽

Microbial Fuel Cells ◽

Electron Donors ◽

Rrna Genes ◽

Anode Surface ◽

Oxide Reduction ◽

Fuel Cell Anodes

ABSTRACT The ability of Pelobacter carbinolicus to oxidize electron donors with electron transfer to the anodes of microbial fuel cells was evaluated because microorganisms closely related to Pelobacter species are generally abundant on the anodes of microbial fuel cells harvesting electricity from aquatic sediments. P. carbinolicus could not produce current in a microbial fuel cell with electron donors which support Fe(III) oxide reduction by this organism. Current was produced using a coculture of P. carbinolicus and Geobacter sulfurreducens with ethanol as the fuel. Ethanol consumption was associated with the transitory accumulation of acetate and hydrogen. G. sulfurreducens alone could not metabolize ethanol, suggesting that P. carbinolicus grew in the fuel cell by converting ethanol to hydrogen and acetate, which G. sulfurreducens oxidized with electron transfer to the anode. Up to 83% of the electrons available in ethanol were recovered as electricity and in the metabolic intermediate acetate. Hydrogen consumption by G. sulfurreducens was important for ethanol metabolism by P. carbinolicus. Confocal microscopy and analysis of 16S rRNA genes revealed that half of the cells growing on the anode surface were P. carbinolicus, but there was a nearly equal number of planktonic cells of P. carbinolicus. In contrast, G. sulfurreducens was primarily attached to the anode. P. carbinolicus represents the first Fe(III) oxide-reducing microorganism found to be unable to produce current in a microbial fuel cell, providing the first suggestion that the mechanisms for extracellular electron transfer to Fe(III) oxides and fuel cell anodes may be different.

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Using an anaerobic digestion tank as the anodic chamber of an algae-assisted microbial fuel cell to improve energy production from food waste

Water Research ◽

10.1016/j.watres.2019.115305 ◽

2020 ◽

Vol 170 ◽

pp. 115305 ◽

Cited By ~ 3

Author(s):

Qingjie Hou ◽

Zhigang Yang ◽

Shuaiqi Chen ◽

Haiyan Pei

Keyword(s):

Fuel Cell ◽

Anaerobic Digestion ◽

Microbial Fuel Cell ◽

Food Waste ◽

Energy Production ◽

Anodic Chamber

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Electricity Generation from Cattle Dung Using Microbial Fuel Cell in Acidification Process of Two-Phase Anaerobic Digestion System

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.113-116.286 ◽

2010 ◽

Vol 113-116 ◽

pp. 286-290 ◽

Cited By ~ 1

Author(s):

Guang Zhao ◽

Li Wei ◽

Fang Ma ◽

Hong Chua ◽

Zhe Wang

Keyword(s):

Fuel Cell ◽

Anaerobic Digestion ◽

Microbial Fuel Cell ◽

Electricity Generation ◽

Cattle Dung ◽

Anode Chamber ◽

Continuous Stirred Tank Reactor ◽

Two Phase ◽

Batch Mode ◽

Main Components

The microbial fuel cell (MFC) constructed by a modified Continuous Stirred Tank Reactor (CSTR) which was used as acidification-phase of two-phase anaerobic digestion system. The experiment was operated as batch mode at mesophilic condition (35°C) to evaluate continue voltage output using cattle dung as substrate in hydrolysis-acidification process. The results illustrated that electricity generation increased noticeably to 300mV after 3 days operation, reached 430mV after 20 days and stabilized electricity generation from 420mV to 470mV in the following 70 days. The pH decreased from 7.15 to 6.65 after 15 days operation and maintained stability from 6.4 to 6.8. The main components of VFA in anode chamber were acetic, propionic and butiric acids. The dominating VFA was acetic acid that predominated untile day 50 and the maximum propionic acid concentration was 15% of total VFA.

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