The SPAjax investment was made mainly because the existing recovery boiler had reached its technical lifetime and no longer met new environmental requirements.
The new recovery boiler commissioned in August 2023 also creates new opportunities for future capacity increases at the Frövi pulp mill.
All performance objectives were met:
• A recovery boiler with a maximum continuous dry solids flow of 1.670 tonnes per day.
• A black liquor concentrator achieving firing conditions with 81% dry solids.
• All process equipment is highly available and fulfils environmental demands.
• Collecting all weak gases from the fibre line and burning them in the new recovery boiler.
• No temperature increase of the effluent.
• Bio-oil as starting and support fuel.
• To meet modern environmental standards, black liquor is burned at high concentration (81% dry solids) with well-staggered combustion and efficient flue gas cleaning.
• Strong gases, methanol and prioritised weak gases from the pulp mill are collected and burnt in the recovery boiler, improving the odour situation surrounding the mill.
• A steam centre with reduction stations producing at various pressure levels was installed, to prepare for a potential future turbine.
• The secondary heating system was upgraded, including a cooling tower with a capacity of 24 MW and air coolers for 65°C and 85°C water to meet discharge temperatures.
• Pitch oil and Hydrotreated Vegetable Oil (HVO) are used for start-up and back-up oil burners.
Ground preparations and rock blasting were carried out according to a tight schedule to finish the concrete base plate and foundations.
The recovery boiler building layout was largely defined before the contract was signed. This proved to be a success factor and of utmost importance, as Andritz had to start its design work immediately in order to provide the design weight for the concrete base plate.
Andritz
“The 2.6 billion SEK investment in a new recovery boiler in Frövi is strategic for Billerud but also for the Swedish industry and is part of the transition to a fossil-free and circular society where packaging is recyclable. The recovery boiler runs on fossil-free biofuel and will contribute to lower air emissions and improving resource and energy efficiency.
Despite a challenging external environment, this important milestone has been achieved according to schedule. Collaboration and communication between the operations, the project, and suppliers have been crucial.”
Richard Morén
Mill Director
The Project’s Achievements:
Investment
251 million euros.
CO2 emissions saved
30.000 tonnes CO2 per year.
Any other sustainable benefits
The modern technology of the new recovery boiler enables:
• Reduced dust and SO2 emissions,
• Improved energy efficiency,
• Improved flue gas purification,
• Safer operational availability,
• 65% reduction of smell,
• Increased pulp production,
• Zero-harm Occupational Health and Safety (OHS) governance.
