Bioelectrochemical Systems with Immobilized Redox Mediators for Power-to-Methane Conversion

Informations projet

BES.WIRE

N° de convention de subvention: 101154191

DOI

10.3030/101154191

Projet clôturé

Date de signature de la CE 7 Mai 2024

Date de début 1 Août 2024

Date de fin 31 Juillet 2026

Financé au titre de

• Marie Skłodowska-Curie Actions (MSCA)

Coût total

Aucune donnée

Contribution de l’UE

€ 230 774,40

Coordonné par

AARHUS UNIVERSITET
Denmark

Periodic Reporting for period 1 - BES.WIRE (Bioelectrochemical Systems with Immobilized Redox Mediators for Power-to-Methane Conversion)

Période du rapport: 2024-08-01 au 2026-07-31

Résumé du contexte et des objectifs généraux du projet

BES.WIRE addresses the challenge of converting CO2 into biomethane using renewable energy. Biomethane can contribute to reducing dependence on fossil natural gas while providing a route for CO2 valorisation and renewable-energy storage. However, CO2-to-CH₄ conversion can be limited by slow reaction kinetics and limited hydrogen availability when performed in biological reactors. BES.WIRE investigates whether immobilised redox mediators – compounds that could facilitate electron transfer between methanogens performing CO2-to-CH₄ conversion and other agents, such as microorganisms or electrodes – can not only overcome these limitations in bioreactors, but also improve the performance of bioelectrochemical reactors. The project pursued three objectives: developing redox-mediator-modified carbon particles, evaluating them as carriers for biomethanation, and developing a bioelectrochemical system for electromethanogenesis.

Travail effectué depuis le début du projet jusqu’à la fin de la période considérée dans le rapport et principaux résultats atteints jusqu’à présent

The project screened conductive and non-conductive granular materials as carriers for ex-situ biomethanation and identified granular graphite as a suitable immobilisation matrix. A phenazine compound, Neutral Red, was successfully immobilised on granular graphite, showing a stable electrochemical response and low leakage. Modified and unmodified graphite granules were subsequently compared in biomethanation experiments. The project also developed a zero-gap approach to screen prospective redox mediators and evaluated granular graphite with immobilised neutral red as a granular electrode for electromethanogenesis. Overall, the project demonstrated redox-mediated charge transfer to methanogens and provided evidence that redox mediators can substantially influence the metabolism of mixed methanogenic communities.

Progrès au-delà de l’état des connaissances et impact potentiel prévu (y compris l’impact socio-économique et les conséquences sociétales plus larges du projet jusqu’à présent)

BES.WIRE established a practical approach to screen granular carriers for biomethanation and showed that physicochemical properties outweigh electrical conductivity. The project provided evidence that Neutral Red can not only merely participate in charge transfer to methanogens, but also steer their metabolism towards other than CH4 products. Repeated experiments also detected an association between hydrogenotrophic methanogenesis and a narrow redox-potential range. These findings open further research directions in redox-controlled biomethanation and conductive biohybrid materials.