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Deciphering the electron transfer mechanisms for biogas upgrading to biomethane within a mixed culture biocathode

Biogas upgrading is an expanding field dealing with the increase in methane content of the biogas to produce biomethane. Biomethane has a high calorific content and can be used as a vehicle fuel or directly injected into the gas grid. Bioelectrochemical systems (BES) could become an alternative for biogas upgrading, by which the yield of the process in terms of carbon utilisation could be increased. The simulated effluent from a water scrubbing-like unit was used to feed a BES. The BES was operated with the biocathode poised at −800 mV vs. SHE to drive the reduction of the CO2 fraction of the biogas into methane. The BES was operated in batch mode to characterise methane production and under continuous flow to demonstrate its long-term viability. The maximum methane production rate obtained during batch tests was 5.12 ± 0.16 mmol m−2 per day with a coulombic efficiency (CE) of 75.3 ± 5.2%. The production rate increased to 15.35 mmol m−2 per day (CE of 68.9 ± 0.8%) during the continuous operation. Microbial community analyses and cyclic voltammograms showed that the main mechanism for methane production in the biocathode was hydrogenotrophic methanogenesis by Methanobacterium sp., and that electromethanogenesis occurred to a minor extent. The presence of other microorganisms in the biocathode, such as Methylocystis sp. revealed the presence of side reactions, such as oxygen diffusion from the anode compartment, which decreased the efficiency of the BES. The results of the present work offer the first experimental report on the application of BES in the field of biogas upgrading processes

This research was nancially supported by the Spanish Government (CTQ 2014-53718-R). P. B-V. and A. V-P. were supported by a project grant from the Catalan Government (2014 FIB1 00119 and 2014 FI-B 00093). LEQUIA has been recognised as consolidated research group by the Catalan Government with code 2014-SGR-1168. Authors acknowledge the collaboration of Lluis Baneras from the Group of Molecular Microbial Ecology (University of Girona), who helped with the microbial analyses

RSC Advances, 2015, vol. 5, p. 52243-52251

Royal Society of Chemistry (RSC)

Author: Batlle Vilanova, Pau
Puig Broch, Sebastià
González Olmos, Rafael
Vilajeliu Pons, Anna
Balaguer i Condom, Maria Dolors
Colprim Galceran, Jesús
Date: 2015
Abstract: Biogas upgrading is an expanding field dealing with the increase in methane content of the biogas to produce biomethane. Biomethane has a high calorific content and can be used as a vehicle fuel or directly injected into the gas grid. Bioelectrochemical systems (BES) could become an alternative for biogas upgrading, by which the yield of the process in terms of carbon utilisation could be increased. The simulated effluent from a water scrubbing-like unit was used to feed a BES. The BES was operated with the biocathode poised at −800 mV vs. SHE to drive the reduction of the CO2 fraction of the biogas into methane. The BES was operated in batch mode to characterise methane production and under continuous flow to demonstrate its long-term viability. The maximum methane production rate obtained during batch tests was 5.12 ± 0.16 mmol m−2 per day with a coulombic efficiency (CE) of 75.3 ± 5.2%. The production rate increased to 15.35 mmol m−2 per day (CE of 68.9 ± 0.8%) during the continuous operation. Microbial community analyses and cyclic voltammograms showed that the main mechanism for methane production in the biocathode was hydrogenotrophic methanogenesis by Methanobacterium sp., and that electromethanogenesis occurred to a minor extent. The presence of other microorganisms in the biocathode, such as Methylocystis sp. revealed the presence of side reactions, such as oxygen diffusion from the anode compartment, which decreased the efficiency of the BES. The results of the present work offer the first experimental report on the application of BES in the field of biogas upgrading processes
This research was nancially supported by the Spanish Government (CTQ 2014-53718-R). P. B-V. and A. V-P. were supported by a project grant from the Catalan Government (2014 FIB1 00119 and 2014 FI-B 00093). LEQUIA has been recognised as consolidated research group by the Catalan Government with code 2014-SGR-1168. Authors acknowledge the collaboration of Lluis Baneras from the Group of Molecular Microbial Ecology (University of Girona), who helped with the microbial analyses
Format: application/pdf
ISSN: 2046-2069
Document access: http://hdl.handle.net/10256/12281
Language: eng
Publisher: Royal Society of Chemistry (RSC)
Collection: MINECO/PE 2015-2017/CTQ2014-53718-R
AGAUR/2014-2016/2014 SGR 1168
Reproducció digital del document publicat a: http://dx.doi.org/10.1039/C5RA09039C
Articles publicats (D-EQATA)
Is part of: RSC Advances, 2015, vol. 5, p. 52243-52251
Rights: Attribution 3.0 Spain
Rights URI: http://creativecommons.org/licenses/by/3.0/es/
Subject: Biogàs
Biogas
Bioelectroquímica
Bioelectrochemistry
Biometà
Biomethane
Title: Deciphering the electron transfer mechanisms for biogas upgrading to biomethane within a mixed culture biocathode
Type: info:eu-repo/semantics/article
Repository: DUGiDocs

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