Onnu, the UK-based pyrolysis technology company, today announced a major strategic partnership with ReGenEarth, marking the launch of a pioneering fully circular integrated anaerobic digestion (AD) and pyrolysis project at ReGenEarth’s Sedgefield site, Hope Farm, an operational dairy farm supplying Arla. Onnu joins the initiative as the official Technology and Engineering Partner.
The Sedgefield development expands ReGenEarth’s existing AD facility into a multi-purpose hub for renewable energy generation, carbon removal, and circular farm-based sustainability. Already powered by cattle waste, the site will now incorporate self-sustaining biochar production through Onnu’s advanced CarboFlow pyrolysis technology, turning everyday agricultural resources into long-term environmental solutions.
A fully circular process, agricultural residue is fed into an anaerobic digester, with the digestate byproduct dried using green energy from the pyrolysis process. This is then pyrolysed itself to create a soil amendment in the form of biochar, sequestering carbon. Residue from harvesting the crops is then used to fuel further anaerobic digestion, thereby starting the process again.
The project forms part of ReGenEarth’s £100 million Green Bond programme with RER Capital, which is enabling a nationwide rollout of integrated AD–pyrolysis sites supported by enhanced feedstock provenance tracking and high-integrity carbon credit pathways.
This partnership follows the first commercial deployment of CarboFlow last month, secured through an agreement with Agrotech Bioenergy in Southeast Asia, where the system will process large volumes of agricultural residues and enable high-integrity carbon removal operations.
At Sedgefield, the installation of dual CarboFlow units alongside the existing anaerobic digestion infrastructure will establish a highly efficient, closed-loop system designed for maximum material and energy recovery. The configuration delivers three key advantages:
- Full utilisation of digestate – rather than being applied to land in wet form, digestate will be dried and thermally converted on-site, creating a stable carbon product with verified market value.
- Diversified feedstock strategy – arboreal residues sourced from the surrounding region provide a second input stream, improving operational resilience and increasing overall carbon removal capacity.
- Energy autonomy – heat recovered from the process will be used to dry digestate, creating a self-sustaining energy loop with minimal external demand.
Once operational on the 3,500-acre farm, Onnu’s CarboFlow system is designed to deliver:
- 2,266 tonnes of biochar annually
- 2.8 MW of recoverable thermal energy
- 4,300 tonnes of CO₂e removal, eligible for carbon credits under the Puro Earth framework
The Sedgefield deployment will act as the blueprint for future integrated AD–thermal conversion projects across the UK and internationally, demonstrating how value recovery, farm productivity and high-integrity carbon removal can operate side by side.
Giles Welch, CEO of Onnu, said: “This partnership demonstrates what is possible when engineering innovation meets a bold sustainability vision. Sedgefield is an ideal setting, a working dairy farm supplying Arla, proving that agriculture, carbon removal and renewable energy generation can be fully integrated in a practical, commercially viable way. CarboFlow was designed precisely for this purpose: to unlock the commercial potential of pyrolysis at scale, making projects like this replicable across the UK.”
Mickey Rooney, CEO of ReGenEarth, added: “We have today reaffirmed our leadership in transforming the anaerobic digestion and standalone power generation sectors, through the final stages of our latest project, integrated pyrolysis solutions. In partnership with Onnu, which provides and manages the cutting-edge technology on-site, ReGenEarth is deploying systems that significantly advance carbon avoidance and sequestration. Our model is built on integration. We don’t just implement technology; we orchestrate the finest talent in the field. By weaving the specialised capabilities of partners like Carma, Puro, Be Zero, and Marsh into a cohesive tapestry of ‘tools, talent and techniques’, we are accelerating a tangible cure for climate change. This unique approach positions ReGenEarth to generate the highest count of high-quality Carbon Credits available anywhere in the world, providing corporations and investors with an unmatched vehicle for achieving their net-zero ambitions.”
