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

Projektinformationen

BES.WIRE

ID Finanzhilfevereinbarung: 101154191

DOI

10.3030/101154191

Projekt abgeschlossen

EK-Unterschriftsdatum 7 Mai 2024

Startdatum 1 August 2024

Enddatum 31 Juli 2026

Finanziert unter

• Marie Skłodowska-Curie Actions (MSCA)

Gesamtkosten

Keine Daten

EU-Beitrag

€ 230 774,40

Koordiniert durch

AARHUS UNIVERSITET
Denmark

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

Berichtszeitraum: 2024-08-01 bis 2026-07-31

Zusammenfassung vom Kontext und den Gesamtzielen des Projekts

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.

Arbeit, die ab Beginn des Projekts bis zum Ende des durch den Bericht erfassten Berichtszeitraums geleistet wurde, und die wichtigsten bis dahin erzielten Ergebnisse

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.

Fortschritte, die über den aktuellen Stand der Technik hinausgehen und voraussichtliche potenzielle Auswirkungen (einschließlich der bis dato erzielten sozioökonomischen Auswirkungen und weiter gefassten gesellschaftlichen Auswirkungen des Projekts)

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.