Innovative bio-based pile cover for biomass chip storage

Mar 2022
Scientific paper published in Energies, based on a project co-funded by the IEA Bioenergy Task 43


There is currently great general interest in reducing the use of fossil-based materials. Fossil-based tarps are still widely used as cover for wood chip storage piles, causing additional waste or requiring further waste treatment in the supply chain. This study aimed to investigate the performance of an innovative bio-based wood chip pile cover compared to conventional treatments (plastic-covered and uncovered) in eastern Finnish conditions. The innovative pile covering method was developed to protect biofuel piles from rain and meltwaters, without the use of plastic. The product consists of a mixture of water, pulp fibre, and a binding agent, which is sprayed over a pile to form a 0.5–2.0-centimetre layer.


The experiment evaluated the drying process during the storage of stemwood chips during 6 months of storage. It included the developments of temperature, moisture content, heating value, energy content, basic density, particle size distribution, and the dry matter losses of a total of six piles. As a result, the forest stemwood chips dried by 11%, with dry-matter losses of 4.3%, when covered with the bio-pile cover. Using the plastic covering, the forest stemwood chips dried by 22%, with dry matter losses of 2.9%. At the end of the experiment, the energy content in plastic-covered piles was 6.1% higher than uncovered piles and 3.1% higher than bio-pile-covered piles.


The trials´ results reveal that the bio-pile cover performed as a forest chip pile cover, as planned, however, the performance of plastic tarps used as cover for forest chips outperformed the innovative bio-pile cover under the given trial conditions. From a scientific perspective it needs to be concluded that the bio-based cover in the studied experimental conditions does not render better storage conditions than those in currently commonly used practices, although fossil substitutional benefits by using the bio-based covers may be achieved, which shows the need for further R&D work in this matter.


Paper reference: Prinz, R.; Routa, J.; Anerud, E.; Bergström, D.; Sikanen, L. Performance of an Innovative Bio-Based Wood Chip Storage Pile Cover—Can It Replace Plastic Tarps? Energies 2022, 15, 1680.




The actual covering of the experimental stemwood piles with the innovative bio-based cover material happens with a specially designed truck