The Finnish forestry company Metsä Group is testing the capture of carbon dioxide from pulp mill flue gases.
Climate change mitigation and the replacement of fossil fuels have given new significance to biogenic carbon dioxide (CO₂). Experts believe that biogenic CO₂ recovered from pulp mill flue gases could be the single most important step towards a new industrial revolution.
At the beginning of September, Metsä Group announced that, together with the technology company Andritz, it had launched a pilot project in the town of Rauma on Finland's west coast to test the capture of carbon dioxide from pulp mill flue gases. Similar technology is already in use elsewhere in the world, for example at coal-fired power stations and waste incineration plants, but its application in the forest industry is a novelty.
“So far, it seems that the new technology also works with pulp mill flue gases,” stresses Kaija Pehu-Lehtonen, head of the carbon dioxide capture project at Metsä Group.
The aim of the pilot project is not yet commercial use, but it has a broader perspective: in the future, biogenic CO₂ could be used as a raw material in the production of synthetic fuels and chemicals as the hydrogen economy develops and solutions for replacing fossil resources come into wider use.
According to Pehu-Lehtonen, various conditions affecting energy consumption, the need for flue gas cleaning and the quality of the captured carbon dioxide will be tested at the Rauma mill this autumn. The experimental plant, which began operating at the end of June 2025, is able to capture around one tonne of CO₂ a day.
“On the basis of the results of the five-month trial, we will also examine the possibility of building a larger experimental plant with a capacity of 30,000-100,000 tonnes of captured carbon dioxide per year, which would be more than a hundred times the capacity of the current experimental plant,” says Pehu-Lehtonen.
No decision has yet been taken on building a larger experimental facility. The reason, the project manager admits, is that the investment would be considerable and the market for biogenic carbon dioxide is still developing. For carbon dioxide capture to be economically viable, partners are needed who can use the captured CO₂ in their own production processes. The entire value chain has to be economically viable.
“We are carrying out the project in stages. Value chains from raw material to finished product are often new and complex, and the parties involved need close cooperation and an understanding of the sector they are working in,” explains Pehu-Lehtonen.
Biogenic carbon dioxide can accelerate the transition to a green economy
Professor Kristian Melin of Lappeenranta University in Finland considers the Metsä Group pilot project valuable because it provides new information about carbon dioxide capture in the forest industry: “It is good to test how new technologies work in forest industry processes. If we can obtain valuable information on a smaller scale, we can make sure that everything will work as intended if larger plants are built in the future.”
Biogenic CO₂ from pulp mills is at present most often an unused by-product with great potential. As the hydrogen economy develops and the production of and demand for synthetic fuels grow, its importance will only increase.
“Today's fuels – methanol, methane, kerosene – contain carbon. A convenient and environmentally friendly source of carbon is precisely captured biogenic carbon dioxide,” explains Professor Melin. In his view, capturing biogenic CO₂ both helps to meet climate targets and can create new business and export opportunities for forestry companies. These are not merely emissions, but a renewable raw material that can link the forestry sector with the hydrogen economy. As the hydrogen economy develops, it could become the most important component of the green transition.
A versatile substitute for fossil raw material
Biogenic carbon dioxide comes from renewable sources such as wood, biomass and agricultural by-products. Unlike fossil CO₂, which releases new carbon into the atmosphere, biogenic CO₂ is part of the short-term carbon cycle and can be used in a climate-neutral way.
Captured biogenic CO₂ can replace fossil raw materials in fuels and chemicals. Combined with green hydrogen, it makes it possible to produce synthetic fuels such as jet fuel, methanol and methane. It can also be used in fertilisers, in plastics production and in construction. The Finnish company Carbonaide, for example, uses CO₂ to harden concrete and make it carbon-negative, while the US company Carbix is developing new technologies that turn emissions into durable building materials.
According to Kaija Pehu-Lehtonen, Metsä Group's aim at present is to speed up the development of the market, but success also requires political decisions: “The development of the market depends on regulation by the European Union and its member states, and also on investment subsidies for the green transition. State subsidies for the green transition are important in order to accelerate investment in the sector.”
Emissions fall, competitiveness rises
Using biogenic CO₂ as a raw material for synthetic fuels and materials can substantially reduce emissions, particularly if the hydrogen is produced using renewable electricity, notes Professor Melin. Replacing fossil fuels also creates opportunities for the Finnish forest industry. “The international competitiveness of the forest industry can be strengthened, particularly in markets where the state or the European Union applies regulatory measures such as blending requirements,” Professor Melin adds.
A blending obligation means that fuel distributors have to add a set proportion of renewable or low-emission fuel, such as synthetic fuel, to fossil fuel. This creates demand for greener fuel options that might otherwise not be competitive on price.
Kristian Melin believes that air transport is a particularly promising sector, also from the perspective of the bioeconomy in the broader sense. European Union regulation, and the ReFuelEU Aviation Regulation in particular, is creating strong demand for more sustainable aviation fuels, including both biological and synthetic alternatives.
“For 2030, the European Union requires the use of at least 3 million tonnes of more sustainable biological aviation fuel, which will open up significant markets for producers of renewable fuels,” says Professor Melin.
Targets after 2050 will be raised, which, according to the professor, could make Finland and Sweden world leaders in this field. “Both Finland and Sweden have abundant sources of biogenic carbon dioxide. Finland has relatively cheap electricity, which is essential for producing renewable hydrogen,” Melin stresses.
Production or storage?
At the beginning of September, Finland and Norway signed a memorandum of understanding that will allow carbon dioxide to be transported from Finland to Norway for storage in geological formations under the seabed.
“This memorandum is an important step for Finland towards introducing carbon dioxide capture and cross-border storage solutions on a large scale,” Finland's Minister of the Environment and Climate Change, Sari Multala, says in a press release.
Norway has been building up experience in the safe storage of carbon dioxide beneath the seabed for almost 30 years and is developing it as a commercial service for other European countries. According to Kristian Melin, such cooperation complements Finland's own solutions and allows a more varied climate policy: “Technical carbon sinks and cross-border storage can certainly complement the use of biogenic carbon dioxide, but in Finnish conditions the more practical solution is to make products from it.”
The market for biogenic CO₂ is expected to grow, but the importance of political leadership will grow too. If the price of fossil fuels is pushed up through taxation or emissions trading, greener alternatives will become even more attractive.
“Of course, there is always a risk that politicians will decide to abandon some of the targets. In any case, it is worth looking for ways to make this new technology as profitable as possible,” concludes Professor Melin.