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Biomass materials play a key role in the renewable energy market as they can serve as a suitable alternative to fossil fuels. However, the quality of the material entering bioenergy plants is often a cause of technical concern. Biomass quality assessment is crucial not only for energy characterization but also for environmental and operational aspects. The goal of this study is to characterize and classify the biomasses used by Italian power plants with reference to the quality classes stated by the ISO standard 17225:2021. A further objective is to verify the ability of the standard to classify heterogeneous and specific biomasses. In this study, more than 900 biomass samples were analyzed. The samples were collected from several Italian power plants with >5 MWe between 2010 and 2020, and the most important physical and chemical parameters were analyzed according to the international standards of reference. The results of the analyses were collected in a large dataset used for subsequent statistical analyses. Statistical analyses applied are Principal Component Analysis and Pearson correlation maps, which showed that the ash content is a fundamental and ideal parameter to assess the biomass quality. Results obtained demonstrate that herbaceous biomasses are of low quality mainly due to the high ash content; a relatively low ash content was found for woody biomasses. [ABSTRACT FROM AUTHOR]

Environmental sustainability has recently shifted towards biodiversity protection via governmental and intergovernmental initiatives (e.g., the UN Millennium Ecosystem Assessment, MA). The life cycle assessment, the widespread method for assessing environmental sustainability, was not created to evaluate impacts on biodiversity. However, several authors recognize its ability to estimate biodiversity loss drivers (impact indices on land use change and ecosystem). The study aims to apply LCA to the forest sector, precisely to the wood–energy chain of Hophornbeam, to cover suggestions of the MA for the biodiversity impact assessment. Six different scenarios for stove (3) and fireplace (3) wood production were analyzed, evaluating two baselines and four alternative scenarios, including sensitivity analyses related to transport distances for the raw materials. The functional unit is 1 MJ of energy. The fireplace combustion scenarios are relatively more sustainable than the stove ones are (2.95–3.21% less). The global warming potential (around 3 g CO2 eq/MJ) is consistent with current European directives on the sustainability of biofuels and scientific literature. The scenarios showed similarities regarding the impact of the categories related to MA drivers. Although biodiversity is protected by limiting forest management, some authors argue that for some species (e.g., Hophornbeam), a rational tree felling could produce biofuels, increasing biodiversity. [ABSTRACT FROM AUTHOR]

Phasing out fossil fuels to renewables is currently a global priority due to the climate change threat. Advocacy for biomass use as an energy source requires assessing the quality biomass and ecological impacts of bioenergy supply chains. This study evaluated the quality of biomass residues from orchards and silviculture transported from different Northern and Central Italy locations and the carbon footprint of a biomass power plant. The total greenhouse emissions were calculated based on primary data for 2017 according to the ISO/TS 14067. All the residue samples showed their suitability for biofuel use. Ash content was relatively low on average (3–5% d.m.), except for grapevine residues (18% d.m.). The lower heating value was within the expected range of 15–21 MJ kg−1 for plant species. The average GHG emission from the power plant was 17.4 g CO2 eq./MJ of electrical energy, with the energy conversion (38%) and transportation of biomass (34%) phases being the main impact contributors. For this study, impacts of residual agricultural residue were about half that of residues from forest management, mainly due to chipping and greater transport distance. Results show that sourcing residual biomass materials for electricity generation close to power plants significantly reduce GHG emissions compared to conventional fossil fuels. [ABSTRACT FROM AUTHOR]