Gasum opens the Nymölla biogas plant, the first in Sweden to produce liquefied biogas from industrial process water from Stora Enso’s Nymölla paper mill

Plans began in 2018, when the two companies signed an agreement to allow Gasum to build a biogas plant next to Stora Enso’s Nymölla mill in the south of Sweden. The process water generated in the mill’s production processes will be treated in the new plant to extract the organic matter, which will then be turned into biogas and later liquefied. Biogas is a renewable fuel that reduces carbon dioxide emissions by up to 90% compared to conventional fossil fuels, such as diesel, when used by the heavy-duty transport segment. 

Three years later, the plant is officially ready to open on April 27, 2021. 

“The driving force behind this pioneering joint venture was the mutual interest in reducing carbon dioxide emissions and creating something valuable out of waste. The result is a plant that can produce 75–80 GWh of liquefied biogas on a yearly basis, enough to supply the annual fuel consumption of up to 200 trucks. The demand for cleaner fuels and transport is huge; the construction and opening of the plant will enable biogas to reach the industrial scale required to meet the needs of maritime, heavy transport and other industry actors looking to reduce their carbon footprint,” says Johanna Lamminen, Chief Executive Officer at Gasum.

“Sustainable operations and resource efficiency are at the core of our business. This project is a good example of how we are able to achieve these goals and help our customers meet their sustainability targets by using our products. We are always trying to find the most innovative, sustainable solutions which calls for partnering with like-minded companies such as Gasum. After three years working on this project, we are excited to see the plant officially open at Nymölla, one of our key sites.” says Kati ter Horst, Executive Vice President, Stora Enso Paper.

The total investment of Nymölla is almost SEK 320 million Swedish, with Gasum investing SEK 270 million in the project, Stora Enso SEK 50 million and an additional SEK 121.5 million came in the form of a grant from the Swedish Environmental Protection agency, through “Klimatklivet”. Klimatklivet is a grant initiative, supporting local and regional innovations to reduce carbon dioxide emissions.

The digital opening ceremony of the Nymölla biogas plant will be attended by Per Bolund, Swedish Minister of Environment and Climate, and Deputy Prime Minister, who will speak on the importance of the circular economy.

The opening of the biogas plant will help the production of biogas (LBG) in Sweden to reach an industrial scale. The increase in production is needed in many sectors, such as the heavy transports, maritime and industry, where there is currently a demand for fuels that can reduce carbon dioxide. The joint venture in Nymölla is a good example of how various industries and sectors can work together to decrease overall emissions.

About the production of biogas from mill process water

The Stora Enso Nymölla mill produces 340,000 tonnes of pulp and 485,000 tonnes of woodfree office paper each year. The Gasum biogas plant is situated in the mill area and is connected to the mill’s existing effluent system.

The received process water is treated in an anaerobic high-rate reactor, where the organic content is transformed into methane – biogas. The anaerobically treated process water, which now contains 50-60% less organic compounds, is led back to the mill’s existing aerobic wastewater treatment plant. The biogas produced is upgraded and liquefied. The liquefaction process cools the biogas to -162 degrees Celsius when it turns into a liquid state.  The liquified biogas is stored in large holding tanks before being collected and transported by Gasum’s trucks to filling stations for example, across the country.