There is a great interest in sustainable energy production and pellets provide an energy source that is both efficient and renewable. A recently published thesis looks at how pellets can be produced more efficiently through different sawdust mixtures and storage times.
– In my research, I have looked at how sawdust from different parts of the tree affects the final product and the role of the drying process, says Workson Siwale, who recently completed his PhD in environmental and energy systems. The goal is to produce pellets with more consistent quality, avoid storage losses and at the same time increase knowledge of how different sawdust mixtures affect the end product.
The study, which focuses on comparing different types of wood for pellet production, provides an important contribution to the knowledge of how process technology and raw materials affect gas generation and storage properties. When storing pellets, various gases are released, some of which are toxic. Pellets also sometimes undergo self-heating, which can lead to self-ignition and storage losses.
– In my studies, I have used different types of wood, such as heartwood and sapwood, to identify where the problems lie. I have also looked at differences in sawdust, from mature and juvenile wood, where juvenile wood sawdust can be used immediately for pellet production without any major problems with off-gassing and self-heating. However, sawdust from mature wood should be stored for 6 to 12 months to avoid problems with gas and heat generation.
You can read the thesis here: Mitigating Off-Gassing and Self-Heating in Fuel Wood Pellets Storage: A Raw Materials Selection and Pre-Treatment Centred Approach.
