Sustainable pulp production as cornerstone of circular economy

A strong circular economy needs efficient and sustainable production

​Delivering increasingly efficient and sustainable production processes represents an important driver of Metsä Fibre’s operations. Implementing these advanced pulp production technologies offers essential benefits to both circular economy and bioeconomy ecosystems. Metsä Fibre’s state-of-the-art Äänekoski bioproduct mill represents a textbook example of efficient and sustainable production at work.


​For this, the second of three articles exploring how the principles of circular economy are materialised in Metsä Fibre’s operations, we turn to the subject of sustainable and circular production methods. The circularity in production can be viewed as the pursuit of an ever more advanced process and resource efficiency within a production ecosystem. Moreover, its implementation can be seen as an ongoing process with consistent ambitions towards attaining a fully recyclable, reusable resource circle. 

Metsä Fibre’s operations, at heart, are based on circulations. Both the manufacturing and use of the products have been designed to minimise waste, create optimal recycling properties, as well as to retain their value. By way of example, Metsä Fibre’s pulp is a fresh fibre and is used in the products made for its many customers. The products are recyclable and the fibre used in the creation of these products can, in many cases, be re-used up to seven times before the biomass is either finally incinerated to create renewable energy, or is stored in the case of products like books, magazines and certain packaging. Additionally, a high percentage of production side streams at Metsä Fibre are utilised, with the bioproduct mill in Äänekoski as a great example. Taken together, these highly eco-efficient processes, and a comprehensive value chain, allow Metsä Fibre to use the pulpwood as efficiently as possible throughout the mill’s entire ecosystem.

Äänekoski bioproduct mill is a great example of utilisation of production side streams, contributing to circular econom

Bringing clarity to complexity

For a working definition of the circular economy, Ilkka Poikolainen, Vice President, Äänekoski bioproduct mill states, “The circular economy is based on the resource efficient use of raw materials and the side streams of production. The idea of a circular economy works best in an industrial ecosystem within which there are actors that produce different end products.” 

The world’s first next-generation bioproduct mill began operations in August 2017 and it is the largest wood processing plant in the Northern Hemisphere. 

“The new mill is called a bioproduct mill, because in addition to pulp, it produces various other bioproducts as well,” explains Poikolainen. “It also produces clearly more bioenergy compared to a traditional pulp mill, and it doesn’t use fossil fuels. Consequently, it does not cause any fossil CO2 emissions. This modern mill, regarding material and resource efficiency, is currently considered world-leading. The aim is to utilise 100% of the raw materials and the production side streams to produce bioproducts and bioenergy.”

Äänekoski bioproduct mill is a great example of utilisation of production side streams, contributing to circular economy

A tale of two economies

Though the terminology is increasingly used in today’s society, for many people, the difference between the two ‘economies’ (circular and bio) is where a certain confusion begins to reveal itself. 

The following statements might help to better understand the meaning of these economies in the context of the production and use of pulp. The circular economy strengthens the eco-efficiency of processes, the utilisation of material streams and the use of carbon from renewable sources to replace the use of additional carbon from non-renewable, fossil sources. The bioeconomy, in turn, utilises renewable resources and side streams efficiently to recyclable bioproducts that replace the use of fossil-based materials. Efficiency also means that side streams, if not applicable to products, can be used to production of renewable energy. 

These are different, but complementary approaches. But what both the bio and circular concepts do have in common is the fact that they are based on increased efficiency of the use of resources and a lower greenhouse gas (GHG) emission. Both ’economies’ are designed to reduce the demand for fossil resources and their ambition is to deliver an increase in value of waste and side streams. 

According to Kaija Pehu-Lehtonen, Senior Vice President, Business Development, Metsä Fibre, one more detail regarding the terminology can be added to further refine the overall understanding, particularly from the perspective of Metsä Fibre’s operations. “The bioeconomy is, I think, very clear, because there is the word ‘bio’, that it is originated from something which is renewable. In the forest industry, we use nowadays the term circular bioeconomy. It is because we think that our many processes and actions are circulating, and the entire forest industry is based on circulation. When you harvest a tree, four new seedlings are planted, for example, so that is the kind of renewability part of nature’s own circular economy.”

Metsä Fibre's sustainable practices contibute to bioeconomy and circular economy

What goes around, comes around

These circulatory processes and actions are fully realised when we focus, in particular, on the workings of a bioproduct mill and the economic role it plays within the bioeconomy. 

Says Poikolainen, “A bioproduct mill is a textbook example of a business economic ecosystem of the bioeconomy. At the heart of a bioproduct facility is an efficient pulp mill and the business network around the mill that produces various bioproducts keeps expanding. These businesses produce bioproducts of a more refined level from the side streams of pulp production, which supports as a whole the competitiveness of the mill entity and it increases the supply for the expanding wood-based bioproduct markets.” 

According to Poikolainen, notable highlights in terms of the advances in circular production being made since Äänekoski opened can be pinpointed. 

“Recently, the production of product gas and sulphuric acid started at the mill. The plant also produces bioenergy and traditional biochemicals, like tall oil and turpentine. In addition, our partner business, Eco Energy SF, refines sludge from the mill’s wastewater treatment plant and turns it into biofuel pellets and in the future, also into biogas.”

Äänekoski bioproduct mill with advanced production methods contributing to circular economy

The production of biochemical products, like the aforementioned tall oil and turpentine, shows that the ‘bioeconomy’ can be seen to add to, and thus enhance the overall ‘circular economy’, by incorporating aspects such as the formulation of new chemical building blocks, new processing routes, new functionalities, and properties of products. But for all these variables to be effective, at the core of operations is the implementation of closed circulation processes. 

Explains Poikolainen, “Central in the processes of the bioproduct mill is a closed circulation, where water and chemicals are being recycled and returned to be re-used in the process. Odourous gases are being refined into sulphuric acid that the mill needs, for example, in the production of a significant bioproduct: tall oil. Thanks to the sulphuric acid plant, the sulphite emissions let into the water systems can be minimised and it reduces the need to transport the chemicals on rails and roads.” 

Adds Pehu-Lehtonen, “First we think of the sustainably sourced raw material, then if we think of our mills, our production, then it is a very closed circulation. The chemical circulations are closed, the water circulation is closed, so in our production there are internal circulations all the time. We use the energy, water, material chemicals, very efficiently. You can use the terms remanufactured or recycled, you can call it closed loops, you can say it in many ways. That is one thing to emphasise because in our processes in the forest industry, we have been circulating things many years before the term circular economy was invented.”

Äänekoski bioproduct mill with advanced production methods contributing to circular economy

From digitalisation to the future of textile fibres

And then there is the increasing computational power, apps and improved software; powerful digital tools that provide an ever more important driver of greater resource and process efficiency, in terms of the delivering of improved circular production. 

“From the angle of digitalisation,” considers Poikolainen, “the bioproduct mill is a pioneer in its field. At the mill, the machines are connected even more than before. New tablets and an application have been taken into use and through the maintenance programs are accessible directly from the field, in addition to the monitoring room. Disturbance notifications can be made through the application as well as ticking off maintenance tasks. The manufacturing process can also be supervised through the application from the field.” 

Taking full advantage of the advances in tech and the work being done by R&D teams, Metsä Fibre’s forward-looking development paths, in terms of advancing circular production, are currently both ambitious and exciting.

Digitalisation at pulp mills contributing to circular economy

“In the future, there are remarkable possibilities with regards to new bioproducts,” states Poikolainen. “Metsä Fibre researches several new products and development paths that are executed in stages. Networks and partners play a significant role. Potential new future bioproducts include the further development of lignin products and pulp-based textile fibres. Metsä Spring, the innovation company of Metsä Group, together with the Japanese Itochu Corporation, are founding a joint company that will invest around EUR 40 million into an industrial demo plant that will produce textile fibres.” 

The demo plant will be in the immediate proximity of Metsä Group’s bioproduct mill at Äänekoski and production will start around the end of 2019. The textile fibre concept that will be used at the demo plant is known as dissolution, which uses a completely new pulp dissolving compound. The raw material will be Metsä Group’s non-dried paper pulp. This new method will be more environmentally friendly than current textile fibre production options. 

To recycle (or re-circulate) words used in the introduction, it is clear that Metsä Fibre’s future ambition is to continue to advance the efficiency of circular production and to use the pulpwood for its most valuable and sustainable purpose.

Äänekoski bioproduct mill is a great example of utilisation of production side streams, contributing to circular economy

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