Seinäjoki is home to Finland’s first industrial-scale biogas plant

A showcase of the circular economy: At the Nurmo biogas plant, manure is turned into fuel and fertilisers for local fields

Text: Mervi Rantakari | Photos: Krista Luoma

“We produce renewable fuel for heavy-duty transport and recycled fertilisers for local fields from manure collected from farms in the region and side streams from the food industry. The entire food value chain benefits from this,” says Matti Lepistö, Plant Manager at Suomen Lantakaasu.

Why was Seinäjoki chosen as the location for the biogas plant?

The region has significant agricultural production, a strong food industry and a good supply of raw materials. We collect slurry from more than 60 farms, including contract farms supplying Valio and Atria as well as other farms in the region.

Our location next to Atria is ideal, as its production facility provides us with raw material in the form of food industry side streams. Another advantage is that there are no residential areas immediately adjacent to the plant.

The location also offers excellent road connections for fuel distribution. St1 Biokraft is opening a biogas filling station near Atria, serving transport operations including those of Atria and Valio.

What is the scale of the operation?

Our goal is to maximise the value we can generate from farm manure and side streams from the food value chain. Our environmental permit allows us to process 240,000 tonnes of raw material annually. Around 200,000 tonnes of this is manure, with the remainder consisting of side streams from Atria, Valio and other food industry operators that cannot be used for food production.

By returning these raw materials to farms as recycled fertilisers and using the biogas in industrial logistics, we are creating an efficient circular system. This supports sustainable development throughout the food value chain.

The plant aims to produce 100 gigawatt-hours of liquefied biogas annually. This amount of energy corresponds to approximately ten million litres of diesel. If a heavy-duty truck consumes an average of 37 litres per 100 kilometres, that amount of diesel would be enough to cover 27 million kilometres, equivalent to driving around the Earth 674 times. So we are talking about a substantial operation.

Our plant is Finland’s first industrial-scale facility producing liquefied biogas. We started operations in April 2026 and are now gradually ramping up towards full production capacity.

What actually happens at the plant?

When a load of manure arrives in Nurmo, the truck is weighed, the load is registered in the system and the manure is unloaded into the receiving area. Before gas production begins, the biomass is processed and hygienised using heat.

The material is then pumped into three enormous digestion tanks. Under anaerobic conditions, microorganisms break down the organic matter, producing methane and carbon dioxide. The material remains in the main digesters for approximately 30 days, followed by another ten days in a secondary digester.

We have had excellent cooperation with the City of Seinäjoki, local residents and farms in the surrounding area.

Sulphur compounds and carbon dioxide are removed from the raw biogas produced in the process. The purified methane is cooled to around -165°C, causing it to liquefy. The end product is LBG, or liquefied biogas, which is used as a renewable fuel for heavy-duty transport.

In addition to gas, the process produces digestate, which we use to manufacture fertilisers.

Water generated in the process is treated and reused, for example as wash water and for diluting biomass. No additional clean water is required for these purposes, and the plant produces no process wastewater that needs to be discharged.

How does the plant benefit local farms?

Farms receive processed recycled fertiliser in return for the manure they supply. Its nutrients are more readily available to plants than those in untreated manure. The use of processed fertilisers also reduces odour when they are spread on fields.

We can return the digestate to farms as it is or process it further into different fertiliser products. Our goal is to supply these fertiliser products more widely to crop farms in the region as well. This can help farmers reduce their fertiliser costs.

Will the Nurmo plant continue to grow?

We are already preparing for expansion! An amendment to the plant’s environmental permit is being prepared that would allow us to increase the amount of raw material received at the facility. In the future, we could also use materials such as grass biomass as feedstock.

Another area of development is capturing the carbon dioxide separated during the biogas upgrading process. We have recently received government investment support for this and are currently assessing a potential investment.

How does the biogas plant contribute to the vitality of Seinäjoki and the wider region?

It is important to us that our operations create benefits as widely as possible. We currently employ ten people directly. In addition, around eight drivers work in transportation, alongside logistics planners.

Local service providers also benefit, including companies providing maintenance, repairs and other services, as we purchase supplies and services from businesses in the region.

Cooperation with the City of Seinäjoki, local residents and farms in the surrounding area has been excellent.

What excites you most about working at the plant?

This work combines technology and microbiology in a fascinating way. It is extremely varied, and I have not yet had two identical working days here.

We continuously take samples from the reactors and closely monitor how the microorganisms are performing. Gas production needs to remain stable.

Although the plant is highly automated, the biological process requires continuous monitoring and expertise. The composition of the feedstock, temperature and microbial activity all affect the end result.

Our biogas plant is a great example of how Seinäjoki and the whole South Ostrobothnia region can build on their strong food value chain to generate new industrial investments and business opportunities.

FACT

The biogas plant is owned by Nurmon Bioenergia Oy. Suomen Lantakaasu owns 90% of the company and Atria 10%. Suomen Lantakaasu is a joint venture between Valio and St1 Biokraft.