Carbon-based gases such as carbon dioxide (CO₂) and carbon monoxide (CO) are often linked to pollution and climate change. However, researchers led by Dr. Lu Feng have been dedicated to finding innovative ways to repurpose these gases into a valuable resource—clean-burning fuel. Their collaborative efforts have resulted in the development of a novel method for producing green biomethane, offering a sustainable alternative to traditional natural gas.
Through a series of five scientific papers published in reputable journals such as Biomass and Bioenergy and Biotechnology for Biofuels and Bioproducts, Dr. Feng and his team have detailed how biofilm-based processes can efficiently produce biomethane with exceptional purity exceeding 96%.
Engineered biofilm for targeted conversion
A biofilm serves as a layer of microorganisms that thrive on surfaces, working collectively to convert gases into methane. Dr. Feng explains that instead of conventional organic waste decomposition in biogas production, the biofilm method captures and processes gas streams using specialized microorganisms within thin biofilms under oxygen-free conditions.
By strategically engineering biofilms within fixed or moving bed reactors, researchers have unlocked new possibilities for precise gas conversion, including the incorporation of selected methane-producing microbes through bioaugmentation to enhance methane production efficiency.
Biofilm reactors maintain high methane quality and tolerance
The developed biofilms offer a stable and efficient process by retaining microbes, enhancing gas-liquid interaction, and expanding the contact surface for reactions. These biofilms also exhibit remarkable tolerance towards detrimental substances that could hinder gas production, such as high levels of ammonia and hydrogen sulfide.
In a study focusing on hydrogen sulfide (H₂S) handling in biofilm reactors, it was found that systems lacking biofilms experienced a significant loss in methane production, whereas biofilm reactors maintained superior methane quality even under elevated H₂S concentrations.
Unlocks great potential from unconventional substrates
One study explored the application of the biofilm method on syngas, a blend of hydrogen and carbon monoxide. This innovative approach could revolutionize waste utilization for biomethane production, enabling the conversion of non-degradable materials like plastic waste and woody biomass into valuable energy sources.
While biofilm reactors demonstrate immense potential, careful control is essential for optimal functionality on an industrial scale. The flexibility and robustness of biofilm-based processes offer a promising platform for future biogas production, contributing significantly to reducing harmful gas emissions while fostering renewable energy production.
More information:
Getachew Birhanu Abera et al, Impact of hydrogen sulphide on biomethanation and the potential mechanisms of mitigation, Biomass and Bioenergy (2025). DOI: 10.1016/j.biombioe.2025.108051
Getachew Birhanu Abera et al, Mitigating ammonia inhibition in in-situ biomethanation using anaerobic moving bed biofilm reactor, Journal of Environmental Chemical Engineering (2025). DOI: 10.1016/j.jece.2025.118355
Begüm Bilgiç et al, Syngas biomethanation using trickle bed reactor, impact of external hydrogen addition at high loading rate, Bioresource Technology Reports (2025). DOI: 10.1016/j.biteb.2025.102197
Lu Feng et al, Bioaugmentation by enriched hydrogenotrophic methanogens into trickle bed reactors for H2/CO2 conversion, Bioresource Technology (2024). DOI: 10.1016/j.biortech.2024.131225
Getachew Birhanu Abera et al, Biofilm application for anaerobic digestion: a systematic review and an industrial scale case, Biotechnology for Biofuels and Bioproducts (2024). DOI: 10.1186/s13068-024-02592-4
Provided by NIBIO – Norwegian Institute of Bioeconomy Research
