Sustainability of wood products: environmental performance of wood pellets’ production by means of Life Cycle Assessment

Nowadays, there is a growing concern and interest in using biomass-based energy sources as alternative to fossil-based ones. In this sense, forests play a key role as source of a renewable material and/or fuel: wood. The aim of this study was to evaluate the environmental impacts related to high-quality pellets production for domestic heating considering the Tuscany region as a representative case study of Italian and European pellets manufacturing, since it is one of the most interesting areas in Italian forest sector, following the Life Cycle Assessment (LCA) methodology and considering a cradle-to-gate perspective. Thus, all the activities involved from wood extraction in no-industrial forests to packed pellets production, ready for delivering to final users were taken into account. No-industrial forestry is widespread in Italy. In mountainous areas, a close-to-nature management regime is applied, i.e. continuous cover forestry management system, aiming at natural regeneration of forest stands. The environmental analysis was performed in terms of seven impact categories: Climate Change, Ozone Depletion, Terrestrial Acidification, Freshwater Eutrophication, Marine Eutrophication, Photochemical Oxidant Formation and Fossil Depletion. Results showed how the most important environmental burdens are related to the use of electricity during pellets production, being responsible for more than 90% of the total in most of the impact categories. Operations carried out in the forest cause a reduced part of the impacts in relation to the entire cycle (from 1% to less than 10% depending on the category).In order to enhance the environmental profile of the factory, four different scenarios for producing and supplying electricity and heat were proposed and investigated. The substitution of the boiler by a cogeneration unit could improve the environmental burdens in all the impacts categories (except in Marine Eutrophication), obtaining the best results when all the electricity requirements are satisfied by this alternative system. The results reported in this study could be considered representative and interesting not only for Italian pellet factories but also for similar factories located in Central Europe because of the key-role played by Italy in the production capacity of that area.