Abstract
Once focused solely on pulp and paper, Swedish-Finnish company Stora Enso (Helsinki, Finland) recently broadened its focus to become a renewable materials company and is working in the packaging, biomaterials, wooden construction, and paper sectors. The company is helping replace fossil-based materials by making new products based on wood and other renewable materials. Focused on innovation, Stora Enso wants to become the leading R&D innovator in its sector.
Helping lead this change and innovation focus is the Stora Enso Biomaterials division, set up in 2012 to reach sectors outside of Stora Enso's traditional markets. The division is focused on growing its key innovation platforms: improving pulp properties, creating a novel sustainable material from cellulose by focusing on regenerated cellulose, improving Microfibrillated Cellulose (MFC) performance, expanding its lignin applications and replacing fossil-based materials for plastics with biobased chemicals.
Stora Enso is also focused on developing its extraction technology platform to produce C5 and C6 sugars as well as lignin. The traditional pulp-making process only uses around 50% of the tree. While cellulose fibers are utilized, the rest of the tree—namely lignin and hemicellulose—is normally burned for energy. Instead of burning the lignin and hemicellulose, Stora Enso uses new technologies to extract hemicellulose, sugars, and lignin from biomass more efficiently to create new, value-added products from these different fragments.
In Virginia, US, Stora Enso is operating the Danville pilot plant, which is further developing its extraction technology. At the plant, the fractionation technology of fibers, lignin, and hemicellulose is being tested using different types of biomass, including wood species and sugarcane bagasse.
The Stora Enso Biomaterials division offers a range of pulp products and the company's lines offer both pulp with long or short fibers. Stora Enso makes Northern Bleached Softwood Kraft (NBSK) made from pine and spruce and Bleached Hardwood Kraft pulp (BHK) made from birch or eucalyptus. These products can be used in a variety of applications, such as paper, packaging, tissue, and specialities.
The Nordic company also offers fluff pulp for hygiene products. For example, the fluff pulp can be used for feminine care products, diapers, air-laid paper, adult incontinence, and other non-woven applications. Stora Enso also offers dissolving pulp, used mainly for textiles, but which can also be used in a variety of products, ranging from sponges and acoustics elements to food.
The company's Biomaterials division's product portfolio also includes LineoTM by Stora Enso, a versatile, high-purity kraft lignin, and MFC, an advanced fiber-based raw material that is 100% renewable and biodegradable and designed to outperform fossil-based materials, such as plastics, in a variety of applications.
Helping Create a Low-Carbon Economy with Biobased Products
Climate change is an increasingly urgent problem and more and more consumers are demanding sustainable solutions. By developing biobased innovations, Stora Enso aims to get the most out of non-food-competing biomass and to reduce costs.
For Stora Enso, there is no doubt that the future will be biobased. By using renewable materials, switching to more energy-efficient production processes, and practicing sustainable forest management, Stora Enso is helping create a low-carbon economy.
Offering many products based on wood, Stora Enso is committed to sustainable forestry throughout its entire operations. All of Stora Enso's wood is fully traceable to its forest of origin, and the company promotes credible forest certification.
To further develop and promote sustainable forestry, Stora Enso signed an international partnership agreement with the Forest Stewardship Council® (FSC). This agreement establishes a long-term strategic collaboration for the development and promotion of sustainable forestry. In Scandinavia and worldwide, Stora Enso centers its activities around sustainably managed forests.
As a raw material, sustainably-managed wood makes economical and ecological sense and ensures the biomass used is renewable while not competing with food or coming from GMO sources.
Lignin—A Wood-Based Alternative to Fossil-Based Materials
Twenty to thirty percent of wood's composition is made out of lignin, and it is the most abundant natural aromatic macromolecule in the world.
Traditionally discarded, lignin was believed to have only limited business opportunities. However, Stora Enso recognized the potential of lignin and increased its focus on this versatile raw material. Stora Enso began commercializing dried Kraft lignin in 2013 and is experienced in industrial-scale lignin production. The company's Sunila Mill in Finland has a capacity of 50,000 tonnes of lignin per year, making Stora Enso the largest Kraft lignin producer in the world.
In 2018, Stora Enso launched high-purity kraft lignin LineoTM and initially focused on its application as a phenol replacement for industrial resins used in the manufacturing of wood panels and engineered wood, such as plywood, oriented strand boards (OSB), laminated veneer lumber (LVL), paper lamination, and insulation material.
Stora Enso's lignin is a stable, free-flowing brown powder with a high dry content, which offers LineoTM a considerable dispersibility and a long storage time. Its reactivity and purity also make it consistent from batch to batch. This confirms LineoTM as a sustainable and efficient product with a predictable cost structure.
A non-toxic raw material, LineoTM can be used in a range of applications where fossil-based materials are currently used. Compared to phenol and formaldehyde, lignin is a more sustainable, stable, and safer alternative. Phenol has numerous issues—it is hazardous, volatile in price and difficult to handle and store. Its smell and toxicity also cause issues within the manufacturing facilities. Conversely, lignin is easy to handle and has stable pricing due to backward integration. This makes it an ideal biobased, non-toxic alternative.
As well as replacing phenol and being a formaldehyde-free binder, Stora Enso is also researching how to use LineoTM for further applications including carbon fiber and hard carbon for energy storage i.e., batteries.
Producing Dissolving Pulp for Sustainable Textiles
Alongside lignin, dissolving pulp will play an important role among Stora Enso's 2019 priorities. For Stora Enso, it is crucial to make the most of the raw materials available, to create renewable products which are less water-intensive, while creating as little waste as possible and limiting their environmental impact. Since 2012, Stora Enso offers dissolving pulp as a raw material for textiles, such as viscose staple fiber (VSF), a biobased alternative for today's fabrics. The company is also researching different ways to produce wood-based textiles. This pulp also has a range of other applications including sponges, biobased acoustic surfaces and food.
When we talk about textiles, it is important to keep in mind this does not only mean clothes. Industries such as furniture and homeware are also increasingly searching for more sustainable textiles. Currently, polyester is the most commonly used textile fiber in the world and it is fossil-based. The second most commonly-used textile fiber – cotton – saw a spike in prices in 2011 due to shortages. Those peaks are becoming increasingly common.
As consumers take notice of those trends, they start to ask where their fabrics come from and demand better, more sustainable options. Wood is a natural solution and the wood used in Stora Enso's dissolving pulp is 100% traceable to its origin.
Traditionally, fast-growing bamboo and eucalyptus have been used for wood-based textiles. However, spruce and birch are also viable alternatives. Stora Enso uses birch as a raw material at its Enocell Mill in Eastern Finland, currently the only mill in the country producing dissolving pulp.
In December 2018, Stora Enso joined the TreeToTextile joint venture, bringing its dissolving pulp experience to help develop more sustainable textile fibers. Originally started in 2014 by H&M group, Inter IKEA group and innovator Lars Stigsson, TreeToTextile will cost-effectively develop new textile fibers from renewable, traceable forest raw material, and regenerated cellulose. The four partners have an equally big stake in TreeToTextile and want to create a strong market for a fiber with a good sustainability performance at attractive cost levels.
Inter IKEA group and H&M group plan to use the fiber in their products—however, the entire industry should be able to benefit from this sustainable fiber since it can also be used in conventional supply chains.
Stora Enso joined TreeToTextile to support the industrialization of the TreeToTextile production process. The technology has been tested in a pilot line in Sweden and is now to be scaled up with the construction of a demonstration plant at one of Stora Enso's Nordic facilities. It is important to find even more sustainable ways to produce cellulosic textile fibers as a replacement for fossil-based synthetic fibers such as polyester.
Future Renewable Materials Objectives
Looking forward, Stora Enso wants to continue focusing on innovation so it can become the leading R&D innovator in its sector. To use renewable materials smartly and efficiently, it is important for Stora Enso to also know the technology behind them.
At the Biomaterials division, the focus will be on its key innovation platforms as well as on diversifying the Nordic pulp business by moving towards a specialized pulp mix. The company is increasing the production of fluff and dissolving pulp and continuously improving production efficiency.
Stora Enso is committed to making the world more sustainable, one renewable product at a time. “Everything made from fossil-based materials today, can be made from a tree tomorrow,” is the company's motto—and Stora Enso is committed to making this a reality.