News

31-03-2025

Revolutionizing pulp production: SAUNA aims for zero-waste, zero-pollution biorefinery operations

With a focus on enhancing energy efficiency, environmental performance, and circularity, the SAUNA project aims to bolster the European green economy through sustainable bio-based processes.

The SAUNA project directly addresses the environmental impact of the kraft process, which accounts for 82% of global virgin pulp production. By developing a novel pulping concept, SAUNA seeks to achieve higher product yield (90%) through targeted wood fractionation, using hot water extraction followed by alkaline oxidation to produce hemicellulose and water-soluble lignin in addition to fibrous pulp. The project aims for an impressive 80% reduction in biogenic CO₂ emissions compared to the kraft process.

The resulting products will be assessed for applications in packaging, adhesives, and polyurethane. A key innovation is the use of selected sulfur-free chemistry, enabling simpler chemical recovery through wet air oxidation. This approach avoids incineration, eliminating CO₂, SO₂, NOx, and TRS emissions, and reducing reliance on fossil fuels.

If implemented across Europe, SAUNA technology has the potential to significantly reduce pollution. A projection indicates that if SAUNA technology replaced kraft pulping in all European pulp biorefineries, the EU could annually save 49 million tons of CO₂, 13.5 ktons of gaseous sulfur compounds, and 36.5 ktons of NOx emissions.

The SAUNA project is a collaborative effort involving 11 partners from across Europe, including research organizations, universities, and industry leaders. Biorizon co-initiator VITO contributes to SAUNA through advanced membrane separation technologies for lignin and hemicellulose recovery, as well as advanced characterization, benchmarking, and application testing of SAUNA lignin and hemicellulose products.

More information

If you want more information about this project or about the possibilities to collaborate with Biorizon, please contact Biorizon’s Lignin Horizon manager Roel Vleeschouwers at roel.vleeschouwers@vito.be or +32 (0)4 74 94 99 09.