1,721,012 research outputs found
LCA of Recycled (NdDy)FeB Permanent Magnets through Hydrogen Decrepitation
Full text linkCompared to conventional fossil-fueled vehicles, electric vehicles offer several environmental benefits. However, even electric vehicles are not completely environmentally friendly because many of their parts are not recycled today. These parts, especially the magnets that power them, end up in landfills at the end of the vehicle's life cycle. This study aims to evaluate the environmental impacts of recycled (NdDy)FeB permanent magnets obtained by means of a novel hydrogen-decrepitation-based, magnet-to-magnet recycling technique. The Life Cycle Assessment methodology was used to compare, on a like-to-like basis, recycled and virgin permanent magnets. The core data provided by an industry partner served as the foundation for modelling the recycling process. Three different functional units were investigated based on three parameters, namely the magnet mass, magnetization coercivity, and energy product. Results revealed that the recycled magnet outperformed the virgin magnet in most impact categories. In terms of carbon footprint, recycling permanent magnets through hydrogen decrepitation would allow for an 1833% reduction with respect to their production from virgin materials, depending on the assumed functional unit
Life Cycle Analysis of a PEM Fuel Cell System for Long-Haul Heavy-Duty Trucks
No full textThe European Union plans to reach net-zero greenhouse gas (GHG) emissions in 2050. In 2020, the transport sector significantly contributed to global energy-related GHG emissions, with heavy-duty vehicles (HDVs) responsible for a substantial portion of road transport emissions in the EU and a notable percentage of the EU's total GHG emissions. Zero-emission vehicles (ZEVs), including fuel cell (FC) vehicles, are crucial for decarbonizing the transport sector to achieve climate neutrality. This paper aims at quantifying the environmental impacts of a 200kW proton exchange membrane FC system for long-haul HDVs with a 40-ton mass and 750 km driving range. The life cycle assessment (LCA) methodology was applied, and a life cycle model of the FC system was developed with a cradle-to-grave boundary. To ensure reproducibility and scalability, results are reported on a kW basis. A sensitivity analysis was performed on key parameters, including hydrogen production route, FC system production location, fuel consumption, FC system size, FC system replacement, and FC material composition. At the cradle-to-gate boundary, GHG emissions of the FC system ranged from 30.5 to 51.4 kg CO2eq/kW. The catalyst was the most impactful component due to the presence of platinum, followed by the balance of plant. In the cradle-to-grave boundary, raw material extraction and production phases were negligible, while the use phase was the main driver of the overall impact of the FC system. Certain equivalences were observed when considering other impact categories
A Study on the Cradle-to-Gate Environmental Impacts of Automotive Lithium-ion Batteries
No full textSeveral factors are influencing the spread of Electric Vehicles (EVs) in the automotive market. However, while battery-electric vehicles emit no tailpipe emissions, the manufacturing phase, particularly the manufacturing of the battery packs, can have significant environmental impacts. In addition, as the EV market expands, there will be a significant increase in demand for critical materials used in lithium-ion batteries, such as lithium, cobalt, and nickel. These materials are essential for producing high-performance batteries, and their global demand is expected to rise rapidly to meet the demands of the expanding market. This paper investigates the main challenges that need to be tackled to reach a sustainable path in the battery industry. A cradle-to-gate boundary is set to focus on raw material extraction, production of precursors, cell and module production, and battery pack assembly. In addition, because 7.8 million tons of EV batteries per year are expected to reach the end-of-life phase by 2040, a brief overview of the recycling issue is provided to investigate the potential usage of recycled material in the early stages of battery production
Impact of Different LCI Modelling Scenarios on the LCA Results, A Case Study for the Automotive Sector
No full textSince vehicles are comprised of thousands of components,
it is essential to reduce the Life Cycle Inventory
(LCI) modelling workload. This study aims to compare
different LCI modeling workload-reducing scenarios to
provide a trade-off between the workload efforts and result
accuracy. To achieve the optimal balance between computational
effort and data specification requirements, the driver
seat is used as a case study, instead of the entire vehicle. When
all the components of a conventional light-duty commercial
vehicle are sorted by mass descending order, seats are among
the first five. In addition, unlike the other components, seats
are comprised of metals as well as a wide range of plastics and
textiles, making them a representative test case for a general
problem formulation. In this way, methodology and outcomes
can be reasonably extended to the entire vehicle. Regarding
the methodology, this study investigates the use of the
International Material Data System (IMDS), thus primary
data are used. First, the Life Cycle Assessment (LCA) of the
reference scenario is evaluated, in which the LCI model is
developed using the full list of substances at element level. The
reference scenario is characterized both by the highest degree
of details and major workload efforts. Second, the authors
consider three workload-reducing scenarios, which they refer
to as: the cut-off, the Verband Der Automobilindustrie (VDA)
and the one-substance-one-material scenarios. Then, granularity
is added, and different levels of disaggregation are
considered for all scenarios. Results indicate that when the
reference scenario is compared to the cut-off scenarios, environmental
impacts are significantly different in certain impact
categories (e.g., Abiotic Depletion) even with the smallest
cut-off (1%). In contrast, when Global Warming Potential
(GWP) is considered, the difference is negligible for any value
of cut-off ranging from 1 to 5%. As a result, if the focus is
solely on the GWP, the cut-off is a viable workload-reducing
strategy. Finally, the VDA and the One-substance-onematerial
scenarios appear to be the best compromises in terms
of workload and accuracy. The One-substance-one-material
scenario achieves the highest accuracy compared to the other
workload-reducing scenarios
Life cycle assessment of an NMC battery for application to electric light-duty commercial vehicles and comparison with a sodium-nickel-chloride battery
Full text linkThis paper presents the results of an environmental assessment of a Nickel-Manganese-Cobalt (NMC) Lithium-ion traction battery for Battery Electric Light-Duty Commercial Vehicles (BEV-LDCV) used for urban and regional freight haulage. A cradle-to-grave Life Cycle Inventory (LCI) of NMC111 is provided, operation and end-of-life stages are included, and insight is also given into a Life Cycle Assessment of different NMC chemistries. The environmental impacts of the manufacturing stages of the NMC111 battery are then compared with those of a Sodium-Nickel-Chloride (ZEBRA) battery. In the second part of the work, two electric-battery LDCVs (powered with NMC111 and ZEBRA batteries, respectively) and a diesel urban LDCV are analysed, considering a wide set of environmental impact categories. The results show that the NMC111 battery has the highest impacts from production in most of the impact categories. Active cathode material, Aluminium, Copper, and energy use for battery production are the main contributors to the environmental impact. However, when vehicle application is investigated, NMC111-BEV shows lower environmental impacts, in all the impact categories, than ZEBRA-BEV. This is mainly due to the greater efficiency of the NMC111 battery during vehicle operation. Finally, when comparing BEVs to a diesel LDCV, the electric powertrains show advantages over the diesel one as far as global warming, abiotic depletion potential-fossil fuels, photochemical oxidation, and ozone layer depletion are concerned. However, the diesel LDCV performs better in almost all the other investigated impact categories
The transport of goods in the urban environment: A comparative life cycle assessment of electric, compressed natural gas and diesel light-duty vehicles
Full text linkA comparative environmental assessment of electric and traditional light-duty vehicles has been performed in the present study. The analysis has focused on an aspect that has often been overlooked in electric mobility Life Cycle Assessments: the transport of goods in urban environments. The analysis has been performed using primary data from the manufacturer for the production of light-duty vehicles and an ad hoc kinematic model for the use phase. This study has ironed out most of the comparison inequalities that arise in a comparative Life Cycle Assessments of vehicles, comparing three light-duty vehicles, which only differ as far as the powertrain configuration is concerned, during a specific function (the delivery of goods in urban environments), where they have resulted to be mutually interchangeable. The electric motor presents advantages in urban environments, because of the numerous stops and regenerative braking that take place during urban deliveries. Its good performance emerges as the load of the vehicle is increased, thus making the comparison with Internal Combustion Engine Vehicles particularly favourable for Electric Vehicles when it comes to the delivery of goods. During the life cycle of the vehicle, these aspects compensate for the higher impacts of Cumulative Energy Demand, Global Warming, Abiotic Depletion - fossil fuels and Photochemical Oxidation that arise from the production of the electric vehicle. These advantages remain negligible in impact categories driven by resource consumption and manufacturing activities, such as abiotic depletion, acidification and eutrophication. Electric mobility is still hindered in these categories by the cumbersome role of batteries
Multidimensional predictions of in-cylinder turbulent flows: Contribution to the assessment of κ-ε turbulence model variants for bowl-in-piston engines
No full textAs is well known, the in-cylinder flow phenomena can strongly affect the engine combustion process and the related emission sources. Therefore, a better understanding of the fluid motion is critical for developing new engine concepts with the most attractive operation and emission characteristics. To that end, multidimensional flow computational codes with reliable turbulence models are useful investigation and design tools. This paper is concerned with mean-flow and turbulence simulation in a motored model engine with a compression ratio of 6.7. The flow configurations comprise an axisymmetric combustion chamber with one centrally located valve and each of a flat piston and cylindrical bowl-in-piston arrangements. The calculations are performed using a non-commercial CFD code that was originally developed by the authors. A finite volume conservative implicit method, applying various order-of-accuracy schemes, is employed for the discretization of the partial differential equations modering the in-cylinder turbulent flow, and the resultant algebraic equations are linearized and sequentially solved by an iterative procedure. Velocity-pressure coupling is ensured by a pressure correction method similar to that of the SIMPLER algorithm ([1]) 1. Results of the simulation are presented at the model engine speed of 200 rpm throughout the engine cycle. They were obtained using three versions of the κ-ε turbulence model (Standard, Two Scale and RNG) which differ from each other for underlying concepts, complexity and accuracy in capturing flow features. Modified boundary conditions with respect to logarithmic wall-functions were applied. Insight was also gained into the nonlinear effects of stress-strain constitutive relation on turbulence modeling. The effects of the equation differencing schemes and computational grid spacing on flow predictions were tested. Then the numerical results were compared to those of LDV measurements and the influence of the κ-ε model variants on the flow field features were examined during the induction stroke and around compression TDC
Comprehensive Techno-Economic Analysis of Battery-Electric Trucks: Evaluating Battery Aging Impact for Regional Delivery Missions
No full textThis study presents a detailed techno-economic assessment of battery-electric trucks, incorporating battery aging effects within a total cost of
ownership (TCO) model. With increasingly stringent emissions regulations, battery-electric trucks are becoming a viable solution in Europe. However, due to uncertainty regarding their long-term cost-effectiveness and fleet operators’ profit-oriented priorities, there is an urgent need for accurate TCO assessment. Existing studies often overlook or oversimplify the impact of battery aging on overall costs. This work addresses this gap by introducing battery aging-related costs through an empirical battery degradation model, evaluated over the vehicle’s lifetime. Key aging costs include a refined
estimation of battery residual value, influenced by degradation and remaining battery life, and potential battery replacement expenses. A case study on a VECTO group 9 truck used for regional delivery missions examines different payloads and battery pack sizes. Furthermore, we consider two different end-of-life (EoL) threshold scenarios for the battery pack, which impact battery replacement expenses and the truck’s residual value.
Costs are categorized as battery-independent or battery-dependent, with battery-dependent costs covering purchase price, energy carrier, residual value, and battery replacement cost. In addition to battery aging that impacts both replacement costs and residual value, the results indicate that energy carrier cost is among the most significant economic factors
SULLA SIMULAZIONE NUMERICA DI APPARATI AD ALTA PRESSIONE IN FASE DI REGOLAZIONE
No full textPubblicazione interna (Politecnico di Torino) PT DE MA 40
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