Securing the circular economy


The unique features of biogas production – organic waste and high temperatures – create a hostile environment for most materials.


Stainless steel is one of few materials that can withstand the aggressive gases and high temperatures common to biogas production. It is both corrosion resistant and keeps life-cycle costs down.


Outokumpu provided 1,500 tonnes of stainless steel match to specific needs.
Surface finish: Cold-worked 2H

One of the world’s biggest biogas plants when it was commissioned in 2009, the 13-hectare biogas park in Könnern, Saxony-Anhalt, Germany, was built by WELtec BioPower. Through an innovative treatment process, biogas produced at the plant is fed directly into the natural gas grid. Annual output is estimated to provide enough energy to heat about 10,000 homes. At the heart of the process are 16 huge digesters. Each digester tank is 6.30 meters tall and 25 meters in diameter.

Because byproducts of the biogas production process include highly corrosive components like sulfur and ammonia, material used in the tanks (and equipment within those tanks) must be corrosion resistant. If corrosion occurs, damage to equipment is inevitable – and that is a particular problem, as restarting a digester after a breakdown is a long and delicate operation.


The cost-effective solution

For construction of the Könnern plant, Outokumpu provided 1,500 tonnes of stainless steel match to specific needs.

In building the digester tanks themselves, cold-worked 2H surface allowed use of thinner steel with no loss of either strength or stability. Because stainless steel is both thin and easy to work with, use of stainless steel in tank construction reduced construction time and logistics costs. And because it is corrosion resistant, there is less need for maintenance. In considering lifecycle costs, that translates into significant cost savings.


Improving reliability and efficiency

Biogas plants put stainless steel to work in multiple ways with optimal grades used in different parts of the application. 

Corrosion resistance remains essential in a process marked by high temperatures, but the fully recyclable material’s other properties are equally important. Excellent formability and gas and water tightness eliminate leakage concerns. And, because stainless steel’s surface is extremely smooth, aggressive substances are unable to attack it. Corrosion is nipped in the bud, an important factor in longevity. In short, stainless steel improves the reliability and efficiency of biogas plants.

Recommended products and insight

Automotive and transportation

In transportation, today’s solutions must be dynamic enough to carry us to the future. Safe, strong, economical, durable and sustainable: Stainless steel delivers a new dimension of unmatched performance.


Stainless steel is the clear choice for use in marine environments – particularly for vessels that are ever lighter, stronger and easier to clean and maintain


The Forta range contains duplex and other high strength stainless steels that enable thinner structures and weight reduction (measured in Rp0.2 > 400 MPa. PRE 16 to 43).

Avesta, Sweden

Fueled by a high-octane blend of advanced technology and a long, proud tradition, the Avesta mill showcases precision performance. One of Outokumpu’s fully integrated production sites, Avesta redefines excellence.

Nyby, Sweden

Steelmaking is deeply ingrained in Nyby. Nearly 200 years after the mill’s founding, Nyby continues to be recognized worldwide for uniquely customized, exceptionally high performance stainless steel.


Outokumpu's four value propositions: recycling maximized, nothing to hide, pays for itself and indispensability showcase Outokumpu's strengths, which answer to key sustainability needs. By selecting Outokumpu's stainless steel, our customers also benefit from these in their own sustainability efforts.

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