Life Cycle Assessment of Wood Chips from Residual Biomass: A Case Study

Abstract

The paper describes the results of a Life Cycle Assessment study of wood chips obtained from a residual forest biomass, to be used for energy purpose. The analysis is referred to 1 kg of wood chips as functional unit. The system boundaries include the collection of the residual biomass, the chipping process of biomass, the collection and transport of wood chips to the energy plant. The results show that the supply chain examined, with reference to the functional unit, causes an impact of 0.027 kg CO2eq and a consumption of 0.406 MJ of primary energy. A dominance analysis was developed to identify the most impactful stages of the production chain: the steps that contribute most to the impacts within the supply chain are the indirect drag and the chipping process, responsible for the 42% of the overall greenhouse gas emissions and primary energy consumption. Lastly, a sensitivity analysis was carried out, to assess the variation of the impacts related to the distance between the wood chips production site and the place of use. The sensitivity analysis shows that is important to have short supply chains within the proposed domain in order to lower the energy and environmental impacts.

Woodchips from Forest Residues as a Sustainable and Circular Biofuel for Electricity Production: Evidence from an Environmental Life Cycle Assessment

“…As stated before, such appreciable variations can be considered mainly related to the differences in the characteristics of the study, its geographic representativeness, and the specifics of the power plant, with particular regard to the electric efficiency. Focusing on the generation of thermal energy or on the production of woodchips our results are instead more aligned with the previous literature, with differences in the order of about −20% and +2% respectively compared to [21] and [29].…”

“…Focussing on the environmental impact evaluation of solid biomass, several LCAbased studies are available in the literature and most of them (for instance [15][16][17][18][19][20][21]) investigated woodchips (of different typologies and for different applications) focussing on the supply chain, but not including the energy conversion. These studies showed the fuel production and transportation as relevant phases of the life cycle and identified chipping and forest operations (e.g., fertilization, harvesting, and extraction) as environmental hotspots within it.…”