Self-heating in drying and quality management of wood chip piles - Haiku

Increased use of wood in Finnish bioeconomy increases a need for large storages of comminuted material in different phases of value chain. Storing of chips, sawdust or bark causes decaying and GHG emissions as well as economic losses. If processes inside piles are known well, we can control them to be used for benefit. The control requires experimental quantification of thermophysical properties of wood chips and properties affecting vapor diffusion inside the wood chip piles. The self-heating and drying will be modelled mathematically, and the model will be tested against full-scale field experiments. The control of the self-heating and drying process takes place through manipulating the pile geometry and size, pile density and chip quality; and consequently, the pile dries to a point when the biological decomposition ceases. As a result of drying the heating value of the chip is increased.