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The environmental impact of Bitcoin mining has raised severe concerns considering the expected growth of 30% by 2030. This study aimed to develop a Life Cycle Assessment model to determine the carbon dioxide equivalent emissions associated with Bitcoin mining, considering material requirements and energy demand. By applying the impact assessment method IPCC 2021 GWP (100 years), the GHG emissions associated with electricity consumption were estimated at 51.7 Mt CO2 eq/year in 2022 and calculated by modelling real national mixes referring to the geographical area where mining takes place, allowing for the determination of the environmental impacts in a site-specific way. The estimated impacts were then adjusted to future energy projections (2030 and 2050), by modelling electricity mixes coherently with the spatial distribution of mining activities, the related national targeted goals, the increasing demand for electricity for hashrate and the capability of the systems to recover the heat generated in the mining phase. Further projections for 2030, based on two extrapolated energy consumption models, were also determined. The outcomes reveal that, in relation to the considered scenarios and their associated assumptions, breakeven points where the increase in energy consumption associated with mining nullifies the increase in the renewable energy share within the energy mix exist. The amount of amine-based sorbents hypothetically needed to capture the total CO2 equivalent emitted directly and indirectly for Bitcoin mining reaches up to almost 12 Bt. Further developments of the present work would rely on more reliable data related to future energy projections and the geographical distribution of miners, as well as an extension of the environmental categories analyzed. The Life Cycle Assessment methodology represents a valid tool to support policies and decision makers. [ABSTRACT FROM AUTHOR]

The growing attention regarding the environmental challenges in the energy sectors pushes the industrial system toward the investigation of more sustainable and renewable energy sources to replace fossil ones. Among the promising alternatives, biomass is considered a valid source to convert the system and to reduce the fossil fraction of the national energy mixes, but its multiple potential uses need an environmental evaluation to understand the actual benefit when it is used as an energy resource. For this purpose, life cycle assessment (LCA) is applied to a wood biomass gasification system aimed to produce electricity and heat generated after the combustion of the produced syngas and the management of the biochar. The aim is to provide a quantitative comparison of (i) a baseline scenario where wood biomass is sourced from waste and (ii) a second scenario where wood biomass is drawn from dedicated cultivation. A further evaluation was finally applied to investigate the environmental implications associated with the biochar composition, assuming it was used on land. The proposed strategies resulted in an environmental credit for both the examined scenarios, but the outcomes showed a net preference for the baseline scenario, resulting in better environmental performances for all the examined categories with respect to the second one. It underlines the potentialities of using waste-sourced biomass. However, according to the Climate Change category, if on-site dedicated biomass cultivation is assumed for the second scenario, the baseline is considered preferable only if the biomass transportation distance is <600 km, which is estimated as a theoretical distance for scenarios to break even. Finally, biochar composition proved a particular concern for toxicity-related categories. This study highlights the importance of applying objective and standardized methodologies such as LCA to evaluate energy production systems based on alternative sources and to support decision-making toward achieving sustainability goals. [ABSTRACT FROM AUTHOR]

The necessity to feed the chemical industry with bio-based platform chemicals encourages the usage of a life cycle perspective in order to evaluate potentialities and drawbacks, before launching them at the industrial scale. In this study, we proposed a life cycle assessment of two bio-based routes for the production of maleic anhydride (1000 kg as the functional unit, FU): from butanol (bio-ButOH MA) and furfural (bio-Furf MA). In both cases, dedicated biomasses were used to feed the pilot plants, since it represents a more realistic scenario. The study considers two levels of analysis. The first one takes into account the simplest situation, in which no energy recovery is considered within the system boundaries. In the second assessment level it is assumed that 100% of the heat released by the reaction is recovered to feed the plant and co-produce steam (available for other commodities). In both scenarios, the production of MA from bio-Furf results in being more competitive. Models were evaluated in terms of carbon footprint (IPCC), cumulative energy demand (CED) and following a multi-impact approach (ReCiPe method). The life cycle impact assessment phase confirms the scores achieved from the application of the E-factor (green metric). In fact, the higher selectivity of the catalytic system used to convert bio-Furf into MA implies a lower amount of raw materials per FU with consequent minor potential impacts on the several impact categories considered. Results, also confirmed by Monte Carlo analysis, could be used to attain future improvements and support the design or the retrofit of innovative industrial plants able to enhance the whole efficiency. [ABSTRACT FROM AUTHOR]

University campuses represent a heterogeneous ecosystem as to social, economic, energetic, and personal travel planning with a huge impact on hosting cities and territories. Sustainable policies are thus fundamental to reduce this impact and to adopt ecological behaviors. The measures for any University Sustainability Plan should be evaluated in terms of GHG emissions, as well as the overall impact of the university itself. Carbon footprint (CF) calculation is a relevant Decision Support tool that allows university organizations to measure and communicate the environmental effects of their activities. The aim of this paper is to present a carbon footprint methodology specifically designed to calculate the carbon footprint of large universities. The methodology was applied to calculate the CF of the University of Bologna by following international standards—i.e., the GHG protocol, the ISO 14064, and the ISO/TR 14069 guide—to understand the environmental impact caused by greenhouse gas emissions from direct and indirect university activities. The study was conducted upon the data available in 2020 and then was compared to the 2018 data, with the aim to recognize if the effect of the pandemic could have altered the results. In 2020, the University of Bologna emitted 16,467 tCO2e which became 15,753 tCO2e considering the offset and avoided emission provided by the internal production of energy from renewable sources. Comparison between 2020 and 2018 shows how, in 2018, most of the emissions came from transportation, representing 74% of the total emissions, while in 2020 almost 50% of total emissions derived by IT procurements. The case application demonstrates the way with which the methodology may be applied to assess environmental impact for complex university campuses. [ABSTRACT FROM AUTHOR]

A 2-year monitoring campaign was carried out within the Marche Region (Italy) to quantify the potential still edible wasted food (seFW) within the sorted (seFWsorted) and unsorted (seFWunsorted) waste streams. Results were elaborated to estimate the distribution of seFW among the five provinces and the amount per capita. Results in terms of total quantities per inhabitants (seFWindex per capita) depict an important variability between districts but almost constant in years (26–38 kg/inhabitants in 2018 and 26–36 kg/inhabitants in 2019). Scores in Marche were then used to study the national situation, adopting the same percentage factors. Analysis was performed on 2019 data. Gradual colour shade was used to identify the Regions with greater seFW production potential. Worst scores are achieved by Lazio, Lombardia and Sicilia (red), followed by others classified as orange and yellow. More than 1.5 Mt potential seFW was estimated at national level, 29% of which is due to the unsorted fraction. Results at national level were used to assess the potential environmental impact related to seFW in terms of climate change. Carbon footprint indicator was quantified per capita (69 kg equivalent carbon dioxide (CO2e)/inhabitant/year in the case of Marche) and overall (3.5 MtCO2e). In addition, an evaluation of the potential economic implications related to the greenhouse gases emitted was made using the Social Cost of Carbon. Results showed that cost of the tCO2e global damage related to seFW in Italy ranges from 35 to 700 M$. [ABSTRACT FROM AUTHOR]

Raw materials form an industrial base to provide the wide range of products and services demanded by industry and society. In particular, manganese, nickel, and natural graphite are examples of materials having a globally consolidated supply chain with interlinked use in steelmaking and essential role in clean energy systems and e‐mobility. A stable material supply chain is hence a priority for import‐dependent regions like the EU and builds upon quantitative system understanding. To this aim, the EU Material System Analysis is applied to analyze the anthropogenic cycle of manganese, nickel, and natural graphite from 2012 to 2016. We provide a detailed characterization of their material stocks, flows, and changes in selected performance indicators including end‐of‐life recycling rate (51% ± 3%, 49% ± 8%, and 8% ± 0% for manganese, nickel, and natural graphite, respectively), self‐sufficiency potential (40% ± 3%, 32% ± 5%, and 5% ± 1%), old scrap ratio (31% ± 0%, 22% ± 2%, and 90% ± 1%), recycling input rate (25% ± 1%, 38% ± 2%, and 3% ± 0%), recycling process efficiency rate (84% ± 2%, 85% ± 6%, and 48% ± 3%), and pre‐consumer losses rate (83% ± 3%, 5% ± 1%, and 24% ± 2%). The achieved results may inform decision‐makers engaged with raw materials recovery and recycling as well as the strategic securement of a reliable material supply to the EU for resilient industrial ecosystems. [ABSTRACT FROM AUTHOR]

Carbon-fiber-reinforced polymers (CFRPs) are increasingly used in a variety of applications demanding a unique combination of mechanical properties and lightweight characteristics such as automotive and aerospace, wind turbines, and sport and leisure equipment. This growing use, however, has not yet been accompanied by the setting of an adequate recycling industry, with landfilling still being the main management route for related waste and end-of-life products. Considering the fossil-based nature of carbon fibers, the development of recovery and recycling technologies is hence prioritized to address the environmental sustainability challenges in a bid to approach mitigating the climate emergency and achieving circularity in materials' life cycles. To this aim, we scaled up and tested a novel semi-industrial pilot plant to pyrolysis and subsequent oxidation of uncured prepreg offcuts and cured waste of CFRPs manufacturing. The environmental performance of the process proposed has been evaluated by means of a life cycle assessment to estimate the associated carbon footprint and cumulative energy demand according to three scenarios. The scale-up of the process has been performed by investigating the influence of the main parameters to improve the quality of the recovered fibers and the setting of preferable operating conditions. The pyro-gasification process attested to a reduction of 40 kgCO2eq per kg of recycled CFs, compared to virgin CFs. If the pyro-gasification process was implemented in the current manufacturing of CFRPs, the estimated reduction of the carbon footprint, depending on the composite breakdown, would result in 12% and 15%. This reduction may theoretically increase up to 59–73% when cutting and trimming waste-optimized remanufacturing is combined with circular economy strategies based on the ideal recycling of CFRPs at end-of-life. [ABSTRACT FROM AUTHOR]