4 examples of an expanding phenomenon
In addition to the current massive investments in the Swedish pulp and paper industry, new companies are born with new ideas and opportunities for new products based on forestry materials and different industrial trends. Because trees contain so many interesting molecules, there are nascent factories in different industries that rely on raw materials and wood products and by-products. In this blog, we have chosen four of these startups that briefly illustrate ways to contribute to a green transition, relying on renewable raw materials.
Patented technology for spinning nanocellulose filaments
CelluXtreme is a research company with patented technology to “spin” nanocellulose filaments. It differs from existing “hand fiber” techniques and pilot scale work is currently taking place to test the technology and eventually commercialize it.
“Our turning technology has nothing to do with coagulation tank viscose processes and is based on ‘conscious flow’ technology,” explains Anna Wiberg, CEO of CelluXtreme. “With our process, we can order and orient the nanocellulose fibrils in a longitudinal direction. The water-based process requires few chemicals, which ensures its durability. 🇧🇷
A jet of nanocellulose is accelerated by two jets perpendicular to it. The nanocellulose fibrils are under the influence of two lateral jets in the longitudinal direction, just like the fibers in the headbox of a paper machine. The system forms a salt gel from the lateral jets which, after drying, transform into ultra-resistant filaments with a diameter of 5-10 µm.
The filaments have incredible properties such as high stiffness and strength, all with a lightness that makes it an interesting product to reinforce the fiber of lightweight composites. Furthermore, these filaments are elastic and flexible in a completely different way than carbon fiber or fiberglass. Functional components can be inserted simultaneously with nanocellulose during the spinning process to finally obtain filaments that support cell growth or exhibit conductive properties. The next step in development is to create a line that allows for prototype development and process design.
Graphene instead of graphite
The company Bright Day Graphene or BDG, which started in 2018, has developed a patent-pending method to produce graphene from lignin. The process has two stages: carbonization by heat and separation. The final product is graphene with graphene oxide and carbon black by-products.
“Graphene flakes have a diameter of 30um, but can reach 100um, while graphene made from graphite is more than 10um”, explains Anna Carlsson, co-founder of BDG. “As larger graphene flakes provide better conductivity, we are investing in applications that rely on electrical properties. The graphite graphene currently on the market is widely mixed with other materials. Electrical applications are our niche, such as energy storage, electronics and sensors.
BDG is in a collaborative project with the Brazilian company Klabin, which owns a LignoBoost factory. As part of the project, its lignin is utilized and converted into graphene for use in sensors used with smart packaging.
So far, we’ve mostly focused on developing the process itself; next step, the construction of a pilot plant with an annual capacity of one ton. Once the process has been verified, the construction of a full-scale plant with a capacity of 80 to 100 tons of graphene will begin. BDG has the plans for this plant and the next step will start as soon as the master plan is completed. The project must be completed in two years. The interesting thing about this process is that graphene provides a very high conversion value compared to other lignin-based applications.
Patented mechanical and chemical pulp to separate oil from water
In just a few years, Biosorbe has gone from producing a kilogram of its GreenAll absorbent product to a full-scale production plan at the pulp mill in Rottneros, Sweden.
Professor Monika Ek, from KTM in Stockholm, has been working for some time on the development of a material for the manufacture of antibacterial diapers, a material that has been shown to be hydrophobic. Biosorbe took an interest in this and, with the help of investors, worked on a larger-scale plant. Once the administrative details were sorted out, planning for a pilot plant at the Rottneros pulp mill took off in autumn 2020.
“Rottneros has great experience in pulp and cellulose and we use thermomechanical and chemical-thermomechanical pulp as raw material in our process”, explains Lars-Erik Sjögren, CEO of Biosorbe. “We use their processing plant, electricity and excess energy from their pulp plan to dry our product. The factory opened in October 2021 and production of the GreenAll is ongoing. 🇧🇷
It is effectively a batch process where the pulp is mixed with chemicals in a grinder. The product is then washed and dehydrated and the resulting pulp is dried by the excess heat of the Rottneros pulp mill. The capacity of the first stage is 500 tons of absorbent product per year.
The result is a hydrophobic and lipophilic absorbent that can absorb 10 to 14 times its own weight. The products in the competition are made of cotton, plastic or concrete. They emit a lot of CO2 during production, require a lot of energy or, like cotton, require large amounts of water.
The first application is for oil spill collection, but as the product separates water from oil, it can also be used to clean up oil-contaminated water, such as on construction sites or for digging mining tunnels. Once the oil is absorbed, it can be converted into energy by burning the product or by adding microbes that will “feed” on the oil. Potential applications in filtration are also envisaged.
Cellfion develops “ion-selective” nanocellulose membranes
Cellfion is the result of a collaboration and several development projects between Linköping University, RISE and KTH. She is developing ion-selective nanocellulose membranes. The company recently benefited from an envelope of 14 million crowns to continue the development of its products.
“The function of these membranes depends on incredibly small, properly modified pores that become active anions or cations,” comments Johan Erlandsson, Research Director at Cellfion. “We observed different groups and combinations of pores that can adhere to a surface to influence its selectivity and thus define its applicability. With the knowledge we have, membranes can be tailored to function as ion conducting systems. The ability to create membranes from scratch for specific systems makes us unique compared to other commercially available membranes. 🇧🇷
In batteries, electrical energy accumulates in the form of substances dissolved in a liquid medium, which is pumped into a cell provided with an electrode where an oxidation and reduction reaction occurs until the battery is discharged or recharged. The selective membrane is absolutely crucial to battery performance, as it must selectively separate the redox-active material from the two liquids, while transporting the selected ions. As the amount of liquid is scaled independently of the cell size, the effect and capacity of the leaking batteries is adaptable to the need. Larger liquid bowls increase the capacity tenfold, while more cells or larger cells increase the potency.
A large potential application for flow batteries is related to the production of renewable energy. The battery is recharged when the wind or sun produces a surplus of electricity and uses it when there is a deficit. These batteries can be used for short and medium term energy supply and to balance commercial demand, an important aspect with the increase in investments in solar and wind energy. There is a huge demand for energy storage; we are therefore talking about several million square meters of membrane that will be in the flow batteries.
This was a narrow choice among the long list of start-ups coming from entrepreneurs and research institutes motivated by the different ways to develop new sustainable products and increase the value of different parts of the tree. At the same time, these players allow the forestry industry to invest in new markets and be part of the vast green transition. I will return to this subject in the new year. Until then, to all readers, a Merry Christmas and a Happy New Year 2023.
Soren Back has left his mark on the Swedish pulp and paper industry since 1976. With a Masters in Chemistry, specializing in pulp and paper technology, Mr. Back ranges from production control to product development, as well as sales, marketing and communications, having held mostly management positions. In recent years, Sören has worked for MoDo Paper, M-real – now Metsa Board – and SP Processum. He now runs his own company, SB Kommunication AB, as a freelance writer and communications consultant for clients primarily in the pulp and paper industry.