Cascading use and classification of used wood for energy in Finland

VTT has studied cascading and energy use of used wood. The use of wood for pulp industry is much higher in Finland than in the EU. As Finland exports a significant part of its wood biomass (as pulp, paper and board, timber and plywood), the cascading cycles of wood products take place outside the Finnish borders, e.g. in other EU Member State. This limits the cascading cycles inside Finland. In addition, the figures show that the energy use of wood industry side streams is very significant in Finland. Guidelines have developed for the classification used wood (post-consumer wood) for energy use including implementation of the legislation and standards in Finland. It is nec­essary to define the impact of possible contaminants on the energy utilisation of used wood. This is helpful for cate­gorisation, as well as for identification and characterisation of the contaminants. The guidelines also include an over­all categorisation used wood. In this classification used wood is divided in 4 categories A, B, C and D. Categories A and B are classified as solid biofuel and class C solid recovered fuels and related standards are used. Fuels falling into category C should be incinerated according to waste incineration legislation. Class D wood is treated by wood pre­servatives and is hazardous waste.