Pellets are a standardized biofuel made from sawdust and planer shavings generated by the wood-processing industry. Through drying and compression, the raw material is transformed into a compact fuel that is easy to store and transport. The consistent fuel properties of pellets provide predictable conditions for combustion and energy production.
Fire-damaged pellets still have energy value
- Article
In October, a fire at SCA’s pellet plant in Härnösand damaged large volumes of pellets. The material is now being repurposed to generate energy, heat, and electricity as sawdust.
Pellets turned back into sawdust
After the fire and the extensive firefighting efforts, much of the pellet stock had broken down into sawdust. Pellets absorb large amounts of water and disintegrate when saturated.
Still a valuable biofuel
Although the wet sawdust has a lower energy content than pellets, it remains a useful biofuel. The material is now being used to generate heat and electricity at several of SCA’s customer heating plants.
Pellet supply remains strong
“It was a significant volume, equivalent to our annual production record. However, it represented just over two weeks of production,” says Johan Stark, Operations Manager, Production at SCA Bionorr.
Running the sawdust through the pelletizing process a second time is not an option for us. When sawdust is heated and compressed, some of the wood’s natural binding agent (lignin) is consumed, and the fibers are altered, making the material more difficult to pelletize. While it is technically possible to produce pellets from this material, doing so would require changes to our production process, potentially including the addition of binding agents, with no guarantee that the end product would meet our quality standards.
Approximately 7 cubic metres (loose volume*) of raw sawdust are required to produce one tonne of pellets. When entering the production process, the raw sawdust has a moisture content of around 50%. After drying, grinding, and pelletizing, the finished pellets have a moisture content of approximately 7%.
* Loose volume (cubic metres) refers to the total external volume of a pile or transport load, including the air spaces between the particles. This is the standard unit used when transporting sawdust and chipped biomass materials.
How much pellet fuel is produced at the Härnösand plant?
The Härnösand plant produces 180,000 tonnes of pellets per year, equivalent to approximately 880 GWh of energy.
One day's production at Bionorr in Härnösand can supply around 160 homes with heating and hot water for an entire year, based on an annual energy consumption of 15,000 kWh per household.
SCA has a total pellet delivery capacity of 500,000 tonnes per year.
Pellets being sprayed with water during firefighting efforts.
Water-soaked pellets beginning to break down into sawdust.
Pellets being sprayed with water during firefighting efforts.
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