Metsä Group will construct a demo plant for lignin refining in connection with its Äänekoski bioproduct mill in Finland. The equipment will be supplied by technology group Andritz. Construction will begin in summer 2024, and the demo plant will be completed in late 2025. The plant's daily capacity will be two tonnes of the lignin product.

Lignin is a substance in wood that binds wood fibres together. In pulp production, lignin is separated from the fibres into black liquor in the chemical cycle and used as bioenergy. Lignin could also be used in chemical and material applications.

The demo plant project also involves Dow, a leading material science company, which will develop high-performance bio-dispersant plasticizers for concrete and gypsum applications, based on the lignin product produced at the plant.

"Our goal is to efficiently use the side streams of pulp production and ensure they produce the greatest possible added value. We want to develop new products made from renewable natural resources that can replace fossil-based raw materials and products," says Ismo Nousiainen, CEO of Metsä Fibre, part of Metsä Group.

Andritz has been developing lignin recovery and modification technology concepts as part of its initiative to enable pulp mills to convert side streams into value-added products.

In a pilot-scale EU project coordinated by VTT Technical Research Centre of Finland, Metsä Group, Andritz and Dow have already demonstrated the suitability of modified lignin as a replacement for fossil-based chemicals in concrete production.

The Äänekoski mill area is Metsä Group's largest, housing a paperboard, veneer and bioproduct mill. Äänekoski is also home to Metsä Group's demo plants for the Kuura textile fibre and Muoto fibre product.