Stora Enso is investing EUR 10 million in the making of bio-based carbon materials for energy storage at Sunila Mill in Finland. We talked with Lauri Lehtonen, Head of Innovation, Biomaterials, about this exciting innovation to replace fossil-based and mined raw materials with renewable solutions.
Lauri Lehtonen, can you tell us more about the investment in Sunila Mill?
“We at Stora Enso believe that everything that is made out of fossil-based materials, can be made of wood tomorrow. This pilot facility for producing bio-based carbon materials is yet another proof point of our innovation work – we are building on our long-term work in extracting lignin from biomass and creating more value out of it. By converting lignin into so-called hard carbon anode materials for lithium-ion batteries, we can offer a product that can replace fossil-based anodes, mainly synthetic graphite, currently used in batteries.”
How can lignin be used for producing such bio-based carbon materials?
“Lignin is one of the main building blocks of a tree. It acts as the glue holding the tree together and contains a considerable amount of elemental carbon and, in particular aromatic carbons, which are needed to form high-grade carbon materials. Lignin makes up 20-30% of the composition of wood.
The process of carbonising biomass consists of several heat and mechanical treatments during which the lignin is formed into a technical carbon material. This process is something excitingly new to our company.”
What makes Sunila Mill the perfect location for the pilot facility?
“Stora Enso has been producing lignin industrially at its Sunila Mill in Finland since 2015. The mill’s annual production capacity is 50 000 tonnes making Stora Enso the largest kraft lignin producer in the world. Today, the lignin produced at Sunila Mill, Lineo™ by Stora Enso, is used, for example, to replace fossil-based components in phenols for adhesives.
Having the pilot facility for producing bio-based energy storage materials at the same mill site brings opportunities for good co-operation in the value chain and for tailoring the raw material for carbon for energy storage according to customer demand.”
What kind of customers is Stora Enso serving with the new product?
“By converting lignin into carbon material, we can offer a renewable product that can replace fossil-based and high-cost anode materials of limited supply currently used in batteries, with battery producers largely located in China. As the world is increasingly electrifying, we see a rapidly growing battery market where companies are looking for high-quality, attractively priced and sustainable materials. Wood-based carbon can be utilised as a crucial component in batteries used in consumer electronics, the automotive industry and large-scale energy storage systems.
With the support of the pilot facility we will be able to explore new markets, new customers, new products and new processes for Stora Enso!”