Swedish forest industry group Södra has selected international technology group ANDRITZ to supply a complete solution for kraft lignin production to its Mönsterås pulp mill in Sweden. This major investment marks Södra’s entry into the lignin market as part of its strategy to make the most of the wood used in pulp production. This will be the first commercial kraft lignin plant in Sweden and the largest in the world.
Kraft lignin is a by-product of pulp production for paper. Today it is used in pulp mills to generate energy. However, it can also be used as a renewable resource to replace fossil-based materials in the chemical industry or form the basis for new biofuels.
“This investment means a lot for Södra and for our kraft pulp mill in Mönsterås. We will make more out of every tree and strengthen our profitability. This is a big investment for Södra and the green transition,” says Karin Dernegård, Mill Manager at Södra Cell Mönsterås.
ANDRITZ will supply a system to recover the lignin contained in the black liquor from the pulping process, making it available to Södra as a saleable product. The scope of supply will also include supporting systems that improve the mill’s environmental performance and ensure full integration of lignin recovery into the existing operations.
The system will be based on the innovative ANDRITZ LignaRecTM lignin recovery process. The lignin drying section, equipped with flash dryer technology, will further process the kraft lignin, ensuring a top-quality product. The integration of the LignaRec process into the Mönsterås pulp mill will be completed by the installation of an ANDRITZ SulfoLoopTM sulfuric acid plant. This plant enables the closure of the sulfur loop, avoiding the purge of sulfate streams even after lignin recovery is implemented.
Lignin and sulfur recovery solutions are part of ANDRITZ’s CircleToZero initiative, which aims to maximize the use of side streams in pulp mills, laying the foundation for zero emissions and zero waste production. With the new order, Södra continues its collaboration with ANDRITZ on the reuse of side streams. The company already operates an ANDRITZ KraftanolTM biomethanol plant at its Mönsterås mill. This plant is the first of its kind in the world to convert by-products of pulp production into purified biomethanol.
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