Denmark is on track for commercial-scale production based on a ‘carbon negative’ pyrolysis process that turns agricultural waste into green fuel, after its government backed plans to scale up technology developed by clean energy pioneer Henrik Stiesdal.

Stiesdal SkyClean, the company behind the project, and its partners received DKr124m ($17.6m) from the Danish Energy Agency to help build a 20MW SkyClean pyrolysis plant at a biogas facility in Vrå, northern Denmark as part of a three-and-a-half year project.

SkyClean plants are based on an oxygen-less pyrolysis technology that actively removes carbon from the atmosphere, using agricultural waste as feedstock to deliver both biochar that can be used as fertiliser and fuel which – as Recharge has previously reported can be upgraded downstream to jet fuel identical to the A-1 variety currently used by airlines.

The more SkyClean fuel is burned, the more CO2 is removed from the air. Other green aviation fuels being developed – biofuels and synthetic “e-fuels” made from green hydrogen combined with captured CO2 – are only carbon-neutral, neither adding to nor reducing overall CO2 levels.

Stiesdal said after the latest award: “The grant means that we and our partners can demonstrate the pyrolysis technology on a commercial scale. We will now test and document many aspects of the technology and the overall value chain in practice. It is a big step forward.”

The Vrå plant will process 40,000 tonnes of residual fibers from the biogas plant to produce 14,000 tonnes of biochar and a “large amount” of green gas. “The production of biochar alone corresponds to approx. 26,000 tonnes of CO2 removed from the atmosphere,” said the company.

The 20MW plant marks another leap for SkyClean, which earlier this year announced that a 2MW “stepping stone facility” would be in service in 2023, itself marking an expansion from a 200kW test project.

Peder Riis Nickelsen, CEO of Stiesdal SkyClean, said: “The grant means that we can continue the very high development pace that we have had with the development of our two current test plants. Now we can scale up times ten and together with our project partners make pyrolysis a well-described and well-documented climate technology."