Green Biorefining Technologies

Lucerne in five different qualities after processing the demonstration platform. From the left: fresh lucerne | press cake fibre | green | leaf protein concentrate | residual (brown) juice. Photo: Ida Marie Jensen

At AU Viborg, a biorefinery demonstration platform is strengthening Denmark’s position as a world leader in research on biorefining of agricultural biomasses such as clover grass and lucerne but also marine biomasses.

The research, carried out by the Green Biorefining Technologies Research Group, builds on more than ten years of experience in processing biomasses that are fractionated into a fibre press cake and a juice.

These two fractions can be developed into high‑value products: the juice can be used for feed and food proteins, fertilizers, and chemicals, while the press cake fibre can be applied in feed, construction materials, and textiles.

The demonstration platform is unique of its kind. Since it was inaugurated in 2019, it has delivered solid data and state-of-the art-results in the technology of green biorefinery with focus on technologies which can be used commercially. The demonstration platform is flexible, and is continuously optimized and innovated - depending on the research- and develop projects it is used for. The machines are made for industrial use and can be scaled and used by stakeholders who wants to work with green biorefinery and produce high value products like feed, food, biomaterials, bio energy and fertilizer.

For environmental and climate reasons, phasing out fossil‑based industries is essential. Production systems should instead become more biobased, ensuring that biomasses - including those arising as byproducts - are utilized in the most efficient ways. In addition, grass is emerging as a promising crop capable of delivering a wide range of indispensable products while also offering environmental benefits. Biorefining is an essential form of production in a biobased and circular bioeconomic society, where the whole bioresource can be utilized.

There is a huge potential for growing more perennial green crops with significant environmental advantages in Denmark. By increasing our domestic agricultural biomass production and green biorefining capacity, we can begin to rely less heavily on imports like soya.

Figure showing the biorefining process and products. Made by Danish Agricultural Agency with a modification by Thalles Andrade, AU

Videos

From grass fibres to textile production (2025) From grass fibres to textile production New research shows that the textile fibres of the future could come from something as common as grass - and it looks surprisingly promising. The work on grass fibres for textile production is part of Green Valleys 2.0, which is funded by the EU - Interreg ÖKS. Listen to Julia Ronkainen, project leader, Wargön Innovation, Nanna Lindgaard Skovborg and Emma Hostrup, research assistants at Aarhus University. Producer: Tobias Stidsen

Grass can be used for more, than you think (2022) (Danish) In Denmark, we import more than one-million-ton protein per year – mainly soy protein from South America and USA. It’s cost-intensive and not very sustainable. Therefore, there’s a huge potential in the project, GO-GRASS, which Michael Støckler talks about in this video. Cause we can extract protein from grass grown in Denmark for feed to monogastric animals – and then avoid importing protein across the planet.

Græs-Prof: A new maceration technique can increase the protein production (2021) (Danish) In the second year of the Græs-Prof project, the demoplatform at Aarhus University tested a new maceration technique of the grass before it goes into the screw press. The macerated grasses are mixed with green juice from the screw press and the watery slurry is pumped through a Rotacutter and then a Disruptor. This way, the grass material is severe macerated before it goes to the screw press, and it’s easy to feed the screw press without any blocking, which has been a problem with fresh cut grass. Preliminary results have shown that this technique can increase the protein production significant compared to the previously techniques.

Great potential in Danish Green Biorefinery – from grass to products (2023) Aarhus University has a unique biorefinery demonstration platform at AU Viborg, Foulum. Here, agricultural and marine biomasses are processed and tested. The biomass is transformed into products that contribute to a more sustainable and biobased society, such as protein for food, animal feed, biomaterials, bioenergy, and biofertilizers. In Denmark, there is huge potential for growing more perennial green crops with significant environmental advantages. By increasing our domestic agricultural biomass production and green biorefining capacity, we can begin to rely less heavily on imports like soya.

GOGRASS: how Danish grass replaces Soy in animal feed (2021) Soy cultivation and import put enormous pressure on natural areas, biodiversity and our climate. We want to change that! At our CBIO demonstration site we are looking for locally grown and sustainable alternatives for animal feed. We do this in corporation with Food & Bio Cluster Denmark, Velas Rådgivning, Institute for Food Studies & Agro industrial Development - IFAU.

AU: Green Biorefinery - A green deal for agriculture (2020) This is a short video from our demonstration platform showing the process from cut grass to juice.