Pyrolysis integrated with biogas production
At Agri Energy in Vrå, SkyClean’s 20 MW pyrolysis plant demonstrates how biomass residues from biogas production can be converted into biochar and green energy at industrial scale.
Industrial pyrolysis in operation
In Vrå, SkyClean integrates slow pyrolysis directly with biogas production. The facility converts digestate fibres into high-quality biochar while supplying surplus process heat to the adjacent biogas upgrading facility.
The project demonstrates industrial-scale biochar production, efficient energy integration, and productive use of agricultural residues within a fully operational system.
Stiesdal SkyClean’s 20 MW pyrolysis plant is located alongside a biogas facility in Vrå, Denmark. Annually, it processes 40,000 tons of dried biogas digestate, a by-product of biogas production.
The pyrolysis process converts biogas digestate fibres into biochar and generates heat used in the biogas plant’s raw methane upgrading process. The biochar is used for carbon capture and storage on farmland.
The annual energy output from the SkyClean plant’s pyrolysis reactor is 57,000 MWh. The annual biochar output equals up to 25,000 tons of captured and stored CO₂e.
SkyClean biochar is free of tar and toxins, and is eligible for certification by European Biochar Certificate. Almost all the carbon in the biochar stays in the soil for centuries or longer.
Standard farming machinery can be used to apply biochar to the soil. Storing carbon on farmland represents a new revenue source for the farmer.
Pyrolysis serves a versatile biomass-to-energy platform. The energy generated by the pyrolysis process can be further converted into Power-to-X solutions, like aviation fuel.
SkyClean pyrolysis plants are capable of using all kinds of residues from agriculture, forestry, and industry.
The Vrå plant is a practical reference for how SkyClean technology can be deployed alongside biogas facilities and other industrial sites with continuous biomass and heat flows.
The 20 MW SkyClean plant in Vrå started operations in October 2024. The plant is developed and operated by Stiesdal SkyClean.
Operating experience
Successful commissioning is only the beginning. Operating the Vrå plant under commercial conditions provides continuous insight into process performance, maintenance, and system integration.
This operational experience supports ongoing optimisation of the SkyClean platform while reducing technical risk for future deployments.
Developed with industrial and research partners
The SkyClean platform has been developed together with leading industrial and research partners, combining practical operational experience with technology development and scientific validation.
Through the SkyClean Scale-up project, partners from across the value chain collaborated to advance industrial pyrolysis, from biomass handling and process engineering to biochar research and plant operation, resulting in the opening of the world’s largest pyrolysis plant in October 2024.
EBC-certified biochar
Biochar produced at the Vrå facility is certified according to the European Biochar Certificate (EBC), a recognised European standard for biochar quality.
The certification adheres to EU thresholds and national legislation with the overall objective of ensuring the production and use of biochar that prevent or reduce any hazards to health and the environment. It includes quality criteria for heavy metals and various toxic substances, such as PAHs, dioxins, and PCBs.
Scan the QR code to view the certificate
Frequently asked questions
What does EBC certification of SkyClean biochar entail?
Biochar produced at the Vrå facility is certified according to the European Biochar Certificate (EBC), a voluntary quality standard for biochar production and use.
The certification includes requirements for production processes, feedstock traceability, and product quality, including limits for heavy metals and other potential contaminants. EBC certification supports transparent documentation and helps ensure that biochar is produced in accordance with recognised environmental and quality requirements.
Planning a pyrolysis project?
SkyClean supports projects from early concept and business case development to system delivery, integration, and operation.