In Finland, the use of wood as a renewable energy source could easily be increased, but untreated wood fuels possess many problematic features that affect the profitability of the supply chain. Moisture is the most important quality issue, as it increases the mass of the fuel in transport, causes dry matter losses, oxidation, and microbial contamination in storage, and reduces the energy yield as well as increases the emissions in combustion. To overcome these problems, wood can be pre-treated with torrefaction, where the feedstock is subjected to thermochemical degradation processes and is transformed to an end product with increased energy density and brittleness, and reduced hygroscopicity and volatiles.Torrefied biomass could increase the co-firing ratio in existing coal-fired plants but the logistics of the material still entail some unsolved issues. Though the material is hydrophobic, it is not protected from capillary water, which in turn may bring about problems - as the material gets wet, the savings obtained in transport, storage and combustion are reset. My studies focus on these matters and aims to clarify the changes that take place during storage.
[Filmed during the May 2015 IBFRA confernece in Rovaniemi, FInland using an iPad and FiLMiC Pro]
11 сен 2024
