Unlocking the Full Potential of Anaerobic Digestion: Opportunities for Farmers
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Understanding Anaerobic Digestion
Anaerobic digestion is a well-established process in the agricultural sector, with many farms investing in AD plants to generate electricity and heat. These systems typically consist of one to three digesters where organic materials such as silage, livestock slurry, and food waste from supermarkets are broken down by bacteria in the absence of oxygen.
During this process, bacteria produce biogas, primarily composed of methane. The digesters are heated to accelerate the reaction, with the organic matter retained in the system for 30-60 days in a continuous cycle. While AD plants are often designed to produce energy for on-farm use, many generate more biogas than their generators can handle.
Turning Excess Biogas into Opportunity
Andrew Parsons explained that surplus biogas is often flared off, meaning farmers are missing out on additional revenue. "Many AD plant owners confirm they could produce more gas than they currently utilise," he said. "This is often due to the mismatch between the plant’s capacity and the size of their generator. Many farmers built their plants slightly larger than needed to ensure energy security, and this oversizing now presents an opportunity."
The good news is that scalable biogas upgrading solutions now exist, allowing farmers to transform surplus biogas into biomethane, a purified, high-value form of methane.
Diversification Through Biogas Upgrading
Bennamann has developed a compact, skid-mounted technology, roughly the size of a 12-foot shipping container, that allows farmers to convert excess biogas into biomethane without the need for large infrastructure investments. "About 99% of what the farmer needs is already in place," Parsons explained. "Our BioCycle system takes biogas containing 50-70% biomethane and upgrades it to as high as 99%."
This purified biomethane can be used to power farm machinery, including tractors and vans, significantly reducing fuel costs. Additionally, there is a growing demand from transport hauliers and local councils looking to use biomethane as a renewable transport fuel.
A Sustainable and Profitable Future
Beyond cost savings, biomethane is a valuable renewable energy source that contributes to decarbonisation efforts. It can replace fossil fuels in engines and industrial applications, lowering greenhouse gas emissions and repurposing waste that might otherwise contribute to environmental challenges.
Furthermore, the UK Government incentivises biomethane production through Renewable Transport Fuel Certificates (RTFCs). When biomethane is derived from waste products such as slurry or food waste, its value in the RTFC scheme is significantly higher than that of biomethane produced from purpose-grown energy crops.
The Potential for Growth
The potential for scalable biogas upgrading in the UK is substantial, with more than half of existing AD plants considered suitable for biomethane production. "This presents a significant opportunity for farmers, the agricultural sector, and rural communities," Parsons emphasised. "By creating local sources of renewable fuel, farms could play a crucial role in decarbonising agricultural operations and rural transport."
As economic pressures mount, maximising the efficiency of existing AD plants is becoming more important. By upgrading surplus biogas to biomethane, farmers can create new revenue streams, lower their carbon footprint, and contribute to a more sustainable agricultural future.
Learn More at Low Carbon Agriculture Show 2025
To explore the latest advancements in anaerobic digestion and biogas upgrading, visit the Low Carbon Agriculture Show 2025. This event will showcase innovative technologies and provide expert insights into how farmers can enhance their AD investments. Don't miss this opportunity to unlock the full potential of your anaerobic digestion system.
