Assessment of the potential use of forest residues generated in the brazilian rainforest for charcoal production

The Amazonian region is the most important timber producer from native's forest exploitation in Brazil. In 2004 there were 82 timber centers, municipalities or micro regions that process at least 100 thousand m³/year of wood logs for industrial purposes. Since the overthrow of the tree to the wood processing, no more than 50% is used, so at least 50% is in a waste form. Most of this waste has no use. Moreover, the region has a strong demand for charcoal to supply the iron industry needs. The residual biomass should be considered as a byproduct of the production chain of wood and its use is a practice to mitigate the environmental impacts of this chain. However, the use of this energy source would also result in impacts to the environment that must be evaluated to verify the sustainability of this proposal. The objective of this research is to assess the impacts associated with a supply chain of renewable energy based on forest residues through the Life Cycle Assessment (LCA). The research is focused on the state of Pará, the greater producer of timber in Brazil. There were identified the main processing centers of timber and therefore the main points of waste generation. The residues were classified according to their origin in exploitation waste (harvest) and processing waste (sawmills). Thus, it was possible to determine an average potential and a logistics structure for the actual use of these. For the LCA there were measured the mass and energy flows involved since the generation of waste until its discharge at the courtyards of charcoal kilns. The research revealed that there is a significant amount of waste that could be used to produce energy in the region. Such use has important impacts, mainly due to intensive use of fossil fuels in transporting the waste. But there are also positive impacts relating to methane emissions avoided by the removal of waste from the forest and the replacement of wood from deforestation for charcoal production. Therefore the use of forest residues for charcoal production is presented as a major initiative to regulate the energy matrix and improve the production chain of wood in the state of Pará. (Résumé d'auteur