Electromethanogenesis for the conversion of hydrothermal carbonization exhaust gases into methane

[EN] Hydrothermal carbonization (HTC) is a biomass conversion process that generates a CO2-rich gaseous phase that is commonly released directly into the atmosphere. Microbial electromethanogeneis (EM) can potentially use this off-gas to convert the residual CO2 into CH4, thus avoiding GHG emissions...

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Detalhes bibliográficos
Autores: Pelaz Guerra, Guillermo, González Arias, Judith, Mateos González, Raúl, Escapa González, Adrián
Tipo de documento: artigo
Estado:Versão publicada
Data de publicação:2023
País:España
Recursos:Ajuntament de Barcelona
Repositório:BULERIA. Repositorio Institucional de la Universidad de León
OAI Identifier:oai:buleria.unileon.es:10612/16948
Acesso em linha:https://hdl.handle.net/10612/16948
Access Level:Acceso aberto
Palavra-chave:Ingeniería de sistemas
Bioelectrochemical systems
Electromethanogenesis
Hydrothermal carbonization
Biocathode
Waste gas
Power-to-gas
Descrição
Resumo:[EN] Hydrothermal carbonization (HTC) is a biomass conversion process that generates a CO2-rich gaseous phase that is commonly released directly into the atmosphere. Microbial electromethanogeneis (EM) can potentially use this off-gas to convert the residual CO2 into CH4, thus avoiding GHG emissions while adding extra value to the overall bioprocess. In the present work, the HTC gas phase was fed to two mixed-culture biocathodes (replicates) polarized at −1.0V vs. Ag/AgCl. Compared to pure CO2, HTC gas had a marked negative effect on the process, decreasing current density by 61%, while maximum CH₄ yield contracted up to 50%. HTC also had an unequal impact on the cathodic microbial communities, with the methanogenic hydrogenotrophic archaea Methanobacteriaceae experiencing the largest decline. Despite that, the present study demonstrates that HTC can be used in EM as a raw material to produce a biogas with a methane content of up to 70%.