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Environmental analysis of selective laser melting in the manufacturing of aeronautical turbine blades
摘要: The exponential growth of additive manufacturing technologies is not only improving production processes to achieve functional requirements for products, but it could also help to minimize environmental impacts. In order to align a green product lifecycle management vision, companies need to implement emerging technologies and define a set of metrics that measure the benefits of the change. Each product requires a particular and optimized manufacturing process plan, and each production phase must achieve a significant reduction of critical metrics for the whole Life Cycle Assessment (LCA). This paper provides a comprehensive and comparative LCA of two manufacturing process plans for the case study of an aircraft engine turbine blade. The first process consists of a combination of Investment Casting and Precision Machining and the second consists in the replacement of Investment casting by Selective Laser Melting as an emergent process for near net shape fabrication. The collected data for the comparison includes Global Warming Potential (GWP), Acidification Potential (AP), Ozone layer Depletion Potential (ODP), Human Toxicity Potential (HTP), and Human Toxicity (HT) with cancer and non-cancer effects. The relative analysis shows that, for the critical indicators, an apparent improvement in CO2 emissions reduction is achieved as well as in the other hazardous emissions. The results showed that the whole lifecycle of Conventional Manufacturing corresponds to 7.32 tons of CO2, while, the emission of the Additive Manufacturing is 7.02 tons of CO2. The results analysis can be used for decision-making, and it can help for facing future comparative works to explore cleaner manufacturing technologies.
关键词: Aerospace Manufacturing,Selective Laser Melting,Life Cycle Assessment,Environmental Impact,Additive Manufacturing
更新于2025-09-11 14:15:04
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Interdisciplinary Collaborations to Address the Uncertainty Problem in Life Cycle Assessment of Nano-enabled Products: Case of the Quantum Dot-enabled Display
摘要: Life Cycle Assessment (LCA) is a powerful tool for assessing the environmental impacts of established processes and products. However, its use in decision-making for sustainable development of emerging technologies is challenging. High levels of uncertainty and lack of data over the complete value chain associated with nascent nano-enabled products (NEPs) makes it difficult to perform LCA studies early in the design process. This study addresses the uncertainty problem faced by LCA, and a demonstration is performed with a case study of quantum dot (QD)-enabled display. The study at hand proposes a dynamic life cycle assessment (dLCA) framework, which emphasizes iterative evaluation and collaborative efforts to tackle the data scarcity problem faced by retrospective (traditional) LCA. Experimental study of two commercially available QD-enabled displays (hand-held tablet with CdSe QD-enabled display and TV set with InP QD-enabled display) is performed for data collection of QD amount and release. After complete digestion, the experimental result shows that the concentration of CdSe (3.92 ± 0.32 μg/cm2) in the QD enhancement film (QDEF) of Tablet is comparable with the concentration of InP (3.56 ± 0.24 μg/cm2) in the QDEF of TV. After accounting for the experimental results, the second traversal of dLCA is performed, and it shows that cumulative energy demand (CED) per unit area for InP QD-enabled displays is 5.28 x 10-3 MJ/cm2 (first traversal was 2.59 x 101 MJ/cm2) and CdSe QD-enabled displays is 3.92 x 10-4 MJ/cm2 (first traversal was 4.32 x 10-2 MJ/cm2). This study highlights the role of collaborative research between life cycle modelers and experimentalists to improve the credibility of LCA results for emerging NEPs. Even though this study is based on the case of QD-enabled displays, the proposed dLCA framework and interdisciplinary collaboration method can also be applied to other emerging technologies.
关键词: Quantum Dots,Environmental Impact,Life Cycle Assessment,Nano-enabled Products,Dynamic LCA
更新于2025-09-11 14:15:04
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Environmental and Economic Trade-Offs of City Vehicle Fleet Electrification and Photovoltaic Installation in the U.S. PJM Interconnection
摘要: Several cities are considering both photovoltaic generation and electric vehicles (EV). A city evaluating a transition to an EV fleet has different decision criteria than private actors. This paper conducts a life cycle assessment and cost-benefit analysis for city vehicle fleet electrification decisions, using Pittsburgh, PA as a case study. The analysis includes several electric-grid scenarios and assesses the installation of distributed photovoltaic at city-owned parking facilities. Costs were included while comparing vehicle options, as were the emissions and externality costs of GHGs, SO2, and NOx from direct and upstream effects. For the vehicles under consideration for Pittsburgh’s fleet, BEVs were always found to have lower GHG emissions than Hybrids. Lowering external costs with fleet electrification, however, was found to be dependent on a rapid transition to a cleaner grid. A peak capacity of about 6,000 kW of PV is possible on Pittsburgh city-owned parking facilities. This capacity would produce greater than 30 times the yearly energy needs of the City’s municipal vehicle fleet. However, the photovoltaic canopy structures over parking spaces potentially make systems cost prohibitive. This study provides a method for cities, counties, and other stakeholders to evaluate the potential benefits and costs of EVs and photovoltaic.
关键词: Electric Vehicles,Solar Power,Life Cycle Assessment,Externalities,Cities
更新于2025-09-11 14:15:04
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Economic and environmental potential for solar assisted central heating plants in the EU residential sector: Contribution to the 2030 climate and energy EU agenda
摘要: Aligning with the ambitious EU 2030 climate and energy package for cutting the greenhouse emissions and replacing conventional heat sources through the presence of renewable energy share inside efficient district heating fields, central solar heating plants coupled with seasonal storage (CSHPSS) can have a viable contribution to this goal. However, the technical performance variation combined with inadequate financial assessment and insufficient environmental impact data associated with the deployment of those innovative district heating systems represents a big challenge for the broad implementation of CSHPSS in Europe. In this context, our paper presents a comprehensive evaluation for the possibility of integrating CSHPSS in the residential sector in various EU member states through the formulation of a multi-objective optimization framework. This framework comprises the life cycle cost analysis for the economic evaluation and the life cycle assessment for the environmental impact estimation simultaneously. The technical performance is also considered by satisfying both the space heating demand and the domestic hot water services. The methodological framework is applied to a residential neighborhood community of 1120 apartments in various EU climate zones with Madrid, Athens, Berlin, and Helsinki acting as a proxy for the Mediterranean continental, Mediterranean, central European, and Nordic climates, respectively. The optimization results regarding the energy performance show that the CSHPSS can achieve a renewable energy fraction above 90% for the investigated climate zones. At the same time, the environmental assessment shows significant improvement when using the CSHPSS in comparison to a natural gas heating system, in those cases the environmental impact is reduced up to 82.1–86.5%. On the other hand, substantial economic improvement is limited, especially in the Mediterranean climate zone (Athens) due to low heating demands and the prices of the non-renewable resources. There the total economic cost of the CSHPSS plants can increase up to 50.8% compared to a natural gas heating system. However, considering the incremental tendency in natural gas prices all over EU nowadays, the study of future plant costs confirms its favorable long-term economic feasibility.
关键词: Life cycle assessment (LCA),2030 climate and energy EU targets,Multi-objective optimization,Life cycle cost (LCC),Central solar heating plant with seasonal storage,Solar community
更新于2025-09-10 09:29:36
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Life cycle assessment of PV-battery systems for a cloakroom and club building in Zurich
摘要: The Office for Building Engineering of the City of Zurich plans the construction of a cloakroom and club building. The building and the floodlights of the surrounding soccer fields use electricity mainly in the evening. That is why the installation of a photovoltaic (PV) system in combination with a battery storage system is evaluated in the pre‐project phase. The environmental footprint of the PV system with multi‐crystalline silicon modules and of current, future, and second‐life lithium‐ion batteries is quantified within the life cycle assessment of the building. The self‐consumption share of PV electricity increases from 31% to 62% if a 60 kWp PV system is complemented by a 100 kWh battery storage. The complementary grid electricity mix strongly influences the environmental impacts of electricity consumed by the cloakroom and club building. The installation of a PV system and a battery storage leads to a 10% to 17% reduction in greenhouse gas emissions compared with the full coverage of the electricity demand by the average Swiss supply mix. The addition of a current battery system does not yield any further reduction compared with the “PV only” option. With the renewable electricity mix of the City of Zurich, the installation of a PV system and a battery storage leads to higher environmental impacts of the electricity consumed by the cloakroom and club building, irrespective of the type of battery used. A future increase in energy density, production optimisations, and second‐life batteries bear a significant potential to reduce the environmental impacts of battery storage systems.
关键词: lithium‐ion,life cycle assessment,building,battery,photovoltaics,self‐consumption
更新于2025-09-10 09:29:36
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Environmental impact analysis applied to solar pasteurization systems
摘要: In many under-developed regions of the world, most people live in rural villages, where the electrical grid is often not available and traditional potabilization systems would be too expensive and technologically too complex to be implemented. Thus every year, millions of people in the world die due to diseases related to water contamination. Solar Pasteurization Systems represents a promising alternative to address such problems, as they can thermally disinfect water employing solar energy alone, without using fossil fuels or electrical grid connection. Evaluating the cradle-to-grave environmental footprint of Solar Pasteurization Systems, and in general of technologies aimed at producing safe drinking water, represents an issue of major importance. This is relevant because an effective solution has to be, at the same time, environmentally and locally sustainable for a given geographical context. In this work, a complete Life Cycle Assessment and Exergo-environmental analysis are performed in order to calculate and compare the eco-profiles of two Solar Pasteurization technologies: a Natural Circulation and a Thermostatic Valve System. Results show that Natural Circulations Systems are generally more environmentally sustainable (0.30 mPt/l) than the Thermostatic Valve System (0.83 mPt/l) thanks to the higher productivity of treated water. A sensitivity analysis is performed to investigate the dependency of the model systems from different operational and environmental conditions, at different installation sites, i.e. Somalia, Brazil and Italy. The main difference is represented by the productivity of the systems. In all cases the solar collector array is the main item responsible for environmental burdens, impacting for almost 45% of the total score. The analysis also shows that the use of solar energy in Pasteurization is important to avoid direct emissions and to lower the global environmental impact connected with thermal energy production compared to the eco-profiles of other widely diffused pasteurization technologies based on the combustion of fossil fuels or biomass that can be used to provide the same function (in general higher than 1.2 mPt/l). Moreover, with the aim of qualitatively assessing the benefit associated with the potential implementation of solar pasteurization systems, an improvement of the sanitary conditions is envisioned, especially in under-developed countries where, definitively, a large scale diffusion would be recommended.
关键词: Solar Pasteurization,Solar Energy,Life Cycle Assessment,Exergo-environmental analysis,Water Disinfection,Water Treatment
更新于2025-09-09 09:28:46