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 carbon-neutral energy at industrial scale.
Industrial pyrolysis in operation
In Vrå, SkyClean integrates slow pyrolysis directly with biogas production. The plant converts digestate fibres into certified biochar while supplying carbon-neutral process heat to the adjacent biogas-upgrading facility.
The project demonstrates industrial-scale biochar production, efficient energy integration and productive use of agricultural residues in a fully operational commercial system.
Stiesdal SkyClean’s 20 MW pyrolysis plant is located alongside a biogas facility in Vrå, Denmark. At maximum capacity it can process 40,000 tons of dried biogas digestate annually, 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 at max capacity 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
Operating the Vrå plant under commercial conditions provides continuous insight into process performance, maintenance requirements and system integration.
This experience supports continuing optimisation of the SkyClean platform and reduces technical risk in future projects.
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 across the value chain collaborated to advance industrial pyrolysis, from biomass handling and process engineering to biochar research and plant operation. The work resulted in the opening of the world’s largest pyrolysis plant for the processing of agricultural residues in October 2024.
EBC-certified biochar
Biochar produced at the Vrå plant is certified under the European Biochar Certificate (EBC), a recognised voluntary standard for biochar quality, production and use.
The certified biochar meets applicable EU and national requirements intended to prevent or minimise risks to health and the environment. The standard includes limits for heavy metals and organic contaminants 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 plant is certified under the European Biochar Certificate (EBC), a voluntary standard covering biochar production and use.
The requirements include production conditions, feedstock traceability and product quality, including limits for heavy metals and other potential contaminants. Certification provides transparent documentation that the biochar has been 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.