In the summer of 2019, the construction project was staffed, and during the summer and autumn of 2019 the project focused on planning and procurement. Technip FMC, with technology from Dutch BTG-BTL was selected as supplier of the pyrolysis plant. Supplier of the chip management system is Procero, a Swedish company based in Örnsköldsvik.
The first shovel of soil was turned on March 23, 2020. During the spring and summer, groundwork was carried out, as well as casting of baseplates and connection preparations. The installation of pyrolysis plant took place in the spring of 2021. After that, the construction of office and workshop space started. The plant was put into operation during the autumn, and on December 7, 2021, the factory was inaugurated.
Sawdust from the nearby sawmill, and other plants, is received through a closed conveyor system and taken to an enclosed storage area. From the storage area, the sawdust is carried to a dryer, where it is dried to a moisture content of around 5%. The air in the dryer is heated using steam from the process. The annual sawdust consumption will be approximately 80,000 tonnes.
From the dryer, the sawdust is sent via an intermediate storage area to the pyrolysis reactor. In the reactor, the sawdust is rapidly heated to around 500°C without any access to oxygen, creating the pyrolysis gas. The coke, the non-volatile part of the fuel, is separated from the pyrolysis gas and burned in a combustion chamber, while the remaining gas is piped off to a condenser.
In the condenser, the pyrolysis gas cools into bio-oil. The bio-oil is purified before being pumped to the storage tank. The non-condensable gases are burned together with the coke in the combustion chamber.
The flue gases from the combustion chamber are used for the production of steam. Some of the steam produced is used to preheat the air for the sawdust dryer and the excess is passed back to the sawmill and used in its drying kilns. The flue gases from the combustion chamber are cleaned in a dust separator before heading up the chimney.
The plant has been designed around BTG-BTL’s pyrolysis concept. Annual production of pyrolysis oil will total around 25,000 tonnes.