29 May 2023: Metsä Fibre, part of Metsä Group, is planning to build a demonstration plant for a modified lignin product in cooperation with ANDRITZ . The aim is to develop the process to separate lignin from black liquor in pulp production and to further process it for new end-uses.

The demonstration plant would have a capacity of about two tonnes per day and would be located within Metsä Group's Äänekoski bioproduct mill. An investment decision on the plant is expected to be made during the course of this year.

In pulp production, lignin that acts as a binder for wood fibres, is removed from fibres. It has traditionally been used for bioenergy production, but it also has a number of other potential uses. The technical assessment and development of the product for end-use applications is being driven by leading material science company, Dow. The high-performance bio-dispersant products produced in the demonstration plant could be used, for example, as bio-based concrete and gypsum water reducer used in construction markets.

"It is important that we actively develop alternatives made from renewable raw materials to replace fossil materials and feedstocks. This will further strengthen our bioproduct mill concept, which aims to utilise all pulp production side streams into products with the highest possible added value," says Ismo Nousiainen, CEO of Metsä Fibre.

The potential of lignin in various applications has been studied for a long time. The production of modified lignin and its suitability for replacing fossil-based chemicals in concrete production, for example, has been demonstrated on a pilot scale in a four-year EU project. The next step will be to assess the techno-economic viability of the technology and the product in a continuous demonstration scale integrated in a bioproduct mill.

“The development of LigniOx technology is an excellent practical example of our CircleToZero initiative, which includes new technologies aimed at minimizing and optimizing pulp mill side streams. The development of LigniOx technology has been done in close cooperation with the entire value chain, and with the support of leading research institutes. The production of a high-grade lignin product from the side stream of the pulping process creates added value and effectiveness both from an environmental and financial point of view, says Kari Tuominen, President & CEO, ANDRITZ Oy.