To enhance the transportation ability of biomass and improve its material properties such as energy density and hydrophobicity, biomass is modified by torrefaction. This process, counting as a mild pyrolysis, takes place between 200 C and 300 C. The densified torrefied product is usable as a biofuel for heat and energy production. Over the past years, research on the torrefaction process itself has been intensified and has led to a further understanding of the main chemical mechanisms and their effects. However, the logistics and handling aspects for the supply chain have hardly been covered yet in research. Similar to the use of wood pellets, factors such as dust generation and the risk of dust explosions could pose a serious issue for transport and storage of densified torrefied products and should therefore be examined. The aim of this paper is to present the state of the art on torrefied biomass and biomass logistics as a basis for the research into the handling characteristics of the supply chain. Firstly, densification and torrefaction are introduced. Following, an overview on literature of the handling aspects of torrefied material is presented. Conclusions will be given on the approach to identify key factors for further research on the handling of torrefied biomass.@en

Dust generation when handling wood pellets is related to the durability of the product, in other words the wear rate of particles subject to forces. During transport, storage and handling wood pellets undergo different forces when interacting with different pieces of equipment. This paper assesses the representativeness of the tumbling can test in relation to transfer chutes, by comparing forces acting on wood pellets in durability tests and in transfer chutes using DEM. The study also incorporates effects such as shape and size variations. The results showed that the tumbling can test underestimates compressive and tangential forces. Since the tested material is subject to milder conditions than in reality, it can be concluded that this test is not representative for the conditions in the supply chain of wood pellets.@en

Dust generation is related to the durability of products, in other words the wear rate of particles subject to forces. During transport, storage and handling the wood pellets are undergoing different forces within different pieces of equipment. For example impact forces when particles fall down or impact geometries and compressive forces when in storage. The objective of this paper is to assess the representativeness of the socalled tumbling can test in relation to handling conditions in the supply chain for wood pellets. Therefore forces acting on particles in the tumbling can on the one side and during loading and discharging of a flat bottom silo on the other side were compared by Discrete Element Model simulations. It can be concluded that in the presented cases the tumbling can underestimates the handling conditions of the material in reality.@en