Effects of elemental composition in wood and different tree compartments on the quality of chips for fuel

Biomass combustion produces such pollutants as particulate matter, NOx, and ozone, which severely affect air quality. In this context, the elemental characterization of wood and the element allocation among tree components can provide important information about the quality of the derived wood fuels and give insight into the choice of the most appropriate combustion technique and the right wood fuel for a given combustion technique. Moreover, knowledge of the different concentrations of elements in the different plant tissues can lead to the identification of the best harvesting strategy aimed at producing wood fuel with the lowest possible environmental impact. This work focused on the allocation in three tree compartments (foliage, branches, and stem) of five important macroelements (K, Mg, Ca, N, and P) in Norway spruce (Picea abies), and pointed out the possible effects of different harvesting strategies and tree age on the quality of the wood fuels. Results showed that the stem-only harvesting system is preferable to whole-tree harvesting in terms of mineral content loss. Results also showed that it is preferable to avoid biomass from young trees because of the poorer fuel quality of the wood chips