This study presents a novel framework to address the challenges of extensive data requirements and uncertainties in road pavement life cycle assessment (LCA). We introduce a streamlined framework ...that employs a structured data underspecification approach. In this study, we categorized the required data into four specificity levels (M1 to M4) to manage data uncertainty in a systematic way. Using 10 case studies with various data specificity levels, our method proves effective in adapting to different degrees of data scarcity. The proposed framework supports a confident decision-making process, in which the comparison indicator shows discerned results at least 90 % of Monte Carlo runs by reducing the data collection burden by 85.7 %. For example, in the Boston pavement scenarios, one can achieve a 90 % reliability level by selectively specifying the maintenance and repair (M&R) activities to an M3-level specificity, while maintaining all other data at a lower level of detail, i.e., M2.
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•RFID tags, readers and backend servers achieve a net environmental impacts reduction.•Miniaturization and novel materials in RFID tags reduce climate change impacts.•Switching to NCM batteries ...reduces freshwater acidification and photochemical ozone creation.•Climate and resource potentials of RFIDs outcompete low-carbon battery chemistry.•RFID-enabled battery supply chains emit less under buyer's markets than seller's markets.
This article explores the current and future technological pathways of RFID components and quantifies their environmental impacts through life cycle assessment (LCA), and also covering the critical materials and energy use of tags, readers, and backend servers. We assess RFID-enabled lithium-ion battery supply chains with different cathode chemistries – lithium nickel cobalt aluminum oxide (NCA), nickel cobalt manganese oxide (NCM) as case applications. The results indicate that miniaturization and novel antenna materials can reduce the current environmental impacts of tags and readers by 60 % and 4 %, respectively. Direct energy consumption and antennas are the main contributors for tags, while microcontrollers and transceivers are the main contributors for readers. Furthermore, the overall environmental improvements of RFID system outweigh their additional environmental impacts. The use of RFID systems in optimizing battery supply process gives higher reductions in climate change and abiotic resource depletion impacts than switching to low-carbon battery chemistries (i.e. using NCM instead of NCA).
In order to develop more sustainable food systems, there is a need to find methods that simultaneously consider environmental impacts and nutritional benefits. The purpose of this study was to ...develop a functional unit to be used in LCA of foods that builds on the nutritional value of food products. We used the content and quality of proteins as a basis, and included dietary context as part of our method, since the nutritional value of a nutrient depends on the total dietary intake. Our method uses the digestible intake of the nine essential amino acids in the product and relates these values to the equivalent total dietary intake of the same amino acids. We also employed simpler functional units such as “gram (g) protein” and “g digestible protein.” We quantified the functional units for three dietary contexts and applied it on LCA results for bread, chicken fillet, minced pork, minced beef, milk and pea soup. The results showed that the relative differences between products changed when using a protein-based functional unit, with the largest change occurring when going from mass as the functional unit to g protein. By introducing protein digestibility, the systematic under-valuation of the animal products was partly avoided with little additional effort. The most advanced functional unit affected the results compared to the mass-based functional unit most, but required significantly more data. The impact of dietary context was smaller than expected; hence, it might be possible to simplify the inclusion of dietary context by using aggregated descriptions of diets. The method presented is valuable for adding an important aspect of nutrition (protein quality and content) to the LCA results of single products, but there is a large scope for development.
•Nutritional based functional units (FU) for foods have been developed.•Protein as FU in food LCA affects conclusions compared to mass as FU.•Digestible protein as FU better reflects the function with limited effort for data.•Amino acid composition and content as FU add limited detail and requires much data.•To include the dietary context involves significantly increased data requirements.
Providing utility instead of selling a product is seen as a promising way to shift the current economy towards sustainability. However, the potential highly depends on the business model design (BMD) ...and quantification is missing. This study proposes an assessment framework that connects the concepts of business model analysis and life cycle assessment (LCA) to systematically identify and evaluate viable and environmentally benign BMDs. An extensive case study for domestic washing machines in Germany validates its effectiveness. The impact reduction potential of the ecologically most promising BMDs is quantified with an LCA scenario analysis. Washing-as-a-service reduces the environmental impacts of the ownership model in all scenarios and impact categories of ReCiPe 2016, also providing valuable insights for resource-intensive energy-using products in general. The framework and its application contribute both, from a methodological as well as from an application perspective to analysing product-service systems and their potential in the circular economy.
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•Techno-economic and environmental study of butadiene process annexed to sugar mill.•Fossil-based butadiene (BD) and bioethanol production considered as the baseline.•Co-combustion of ...coal with biomass improves the economic due to economies of scale.•Bio-BD shows better performance over the investigated environmental impact categories.•Bioethanol production has higher probability of economic feasibility than Bio-BD.
In this study, lignocellulose biorefineries annexed to a typical sugar mill were investigated to produce either ethanol (EtOH) or 1,3-butadiene (BD), utilizing bagasse and trash as feedstock. Aspen simulation of the scenarios were developed and evaluated in terms of economic and environmental performance. The minimum selling prices (MSPs) for bio-based BD and EtOH production were 2.9–3.3 and 1.26–1.38-fold higher than market prices, respectively. Based on the sensitivity analysis results, capital investment, Internal Rate of Return and extension of annual operating time had the greatest impact on the MSP. Monte Carlo simulation demonstrated that EtOH and BD productions could be profitable if the average of ten-year historical price increases by 1.05 and 1.9-fold, respectively. The fossil-based route was found inferior to bio-based pathway across all investigated environmental impact categories, due to burdens associated with oil extraction.
Purpose
This paper reviews the state-of-the art research in life cycle assessment (LCA) applied to buildings. It focuses on current research trends, and elaborates on gaps and directions for future ...research.
Methods
A systematic literature review was conducted to identify current research and applications of LCA in buildings. The proposed review methodology includes (i) identifying recent authoritative research publications using established search engines, (ii) screening and retaining relevant publications, and (iii) extracting relevant LCA applications for buildings and analyzing their underpinning research. Subsequently, several research gaps and limitations were identified, which have informed our proposed future research directions.
Results and discussions
This paper argues that humans can attenuate and positively control the impact of their buildings on the environment, and as such mitigate the effects of climate change. This can be achieved by a new generation of LCA methods and tools that are model based and continuously learn from real-time data, while informing effective operation and management strategies of buildings and districts. Therefore, the consideration of the time dimension in product system modeling is becoming essential to understand the resulting pollutant emissions and resource consumption. This time dimension is currently missing in life cycle inventory databases. A further combination of life cycle impact assessment (LCIA) models using time-dependent characterization factors can lead to more comprehensive and reliable LCA results.
Conclusions and recommendations
This paper promotes the concept of semantic-based dynamic (real-time) LCA, which addresses temporal and spatial variations in the local built and environmental ecosystem, and thus more effectively promotes a “cradle-to-grave-to-reincarnation” environmental sustainability capability. Furthermore, it is critical to leverage digital building resources (e.g., connected objects, semantic models, and artificial intelligence) to deliver accurate and reliable environmental assessments.
With the focus of highway development transitioning from construction to maintenance, a comprehensive understanding of the characteristics and influencing factors of carbon dioxide (CO2) emissions ...from highway maintenance activities is crucial for formulating effective strategies to promote the low-carbon development of road infrastructure. However, the quantitative relationships between CO2 emissions from highway maintenance schemes and factors such as pavement deterioration, traffic volume, and road grade remain unclear owing to a lack of comprehensive, multi-category, and real data. Using real maintenance data from 340 arterial highway segments in China, this study conducts the life cycle assessment (LCA) to estimate CO2 emissions from maintenance activities and examines the primary emission sources among various structural layers and materials. Furthermore, multiple linear regression (MLR) analysis is conducted to investigate the impact of traffic volume, road grade, and pavement deterioration on CO2 emissions from maintenance projects, and factors influencing the early-stage degradation of pavement performance. The results demonstrate that average CO2 emissions from heavy rehabilitation projects are 6.97 times higher than those from medium rehabilitation projects. Emissions from heavy rehabilitation projects exhibit a significantly negative linear relationship with the riding quality index (RQI) before maintenance (p < 0.05), and emissions from medium rehabilitation projects show a significant negative linear relationship with the pavement condition index (PCI) before maintenance (p < 0.05). Emissions from heavy and medium rehabilitation projects are significantly positively correlated with heavy vehicle traffic volume before maintenance (p < 0.05). Moreover, the early-stage degradation of PCI after heavy rehabilitation and RQI after medium rehabilitation exhibit significantly negative linear relationships with their respective indicators before maintenance (p < 0.05). The early-stage degradation of RQI after heavy rehabilitation is significantly positively correlated with CO2 emissions from the base course and cushion layers (p < 0.05). The findings emphasize that timely maintenance and reduction of CO2 emissions from asphalt mixing equipment are essential for mitigating emissions from road maintenance. This study offers valuable insights for advancing the low-carbon development of highways in temperate regions.
Sustainable and smart mobility and associated energy systems are key to decarbonise the EU and develop a clean, resource efficient, circular and carbon-neutral future. To achieve the 2030 and 2050 ...targets, technological and societal changes are needed. This transition will inevitably change the composition of the future EU fleet, with an increasing share of electric vehicles (xEVs). To assess the potential contribution of lithium-ion traction batteries (LIBs) in decreasing the environmental burdens of EU mobility, several aspects should be included. Even though environmental assessments of batteries along their life-cycle have been already conducted using life-cycle assessment, a single tool does not likely provide a complete overview of such a complex system. Complementary information is provided by material flow analysis and criticality assessment, with emphasis on supply risk. Bridging complementary aspects can better support decision-making, especially when different strategies are simultaneously tackled. The results point out that the future life-cycle GWP of traction LIBs will likely improve, mainly due to more environmental-friendly energy mix and improved recycling. Even though second-use will postpone available materials for recycling, both these end-of-life strategies allow keeping the values of materials in the circular economy, with recycling also contributing to mitigate the supply risk of Lithium and Nickel.
Cemented carbides are of great importance for the manufacturing industry. The outstanding properties of high hardness and wear resistance of this material, consisting mainly of tungsten carbide ...cemented with cobalt (WC-Co), have caused its use in a wide range of applications. The aim of this study is to provide comprehensive and detailed cradle-to-gate life cycle inventory (LCI) data for the typical non-Chinese production of WC-Co, which is assumed to take place in Canada and the United States. Different scenarios are presented regarding recycling rate and a life cycle impact assessment (LCIA) is conducted to illustrate the applicability of the LCI data. The LCI results in this study are of similar magnitude or lower compared to previous studies and indicate that the typical non-Chinese production requires less energy compared to Chinese production. The LCIA results show that the mining, hydrometallurgy and powder metallurgy phases in general dominate the cradle-to-gate life cycle impacts. Most of the impacts are caused by a limited number of inputs and outputs (e.g. kerosene, sulfidic tailings, water use during mining and electricity use), and recycling greatly reduces the impacts. A comparison with Chinese tungsten carbide (WC) powder production showed that the LCIA results in non-Chinese WC production were lower for climate change, photochemical oxidant formation and water depletion, but higher for terrestrial acidification, ozone depletion and freshwater eutrophication. The LCI data and the LCIA results for non-Chinese production can subsequently be used in product-specific cradle-to-grave life cycle assessments involving WC-Co or any of its precursors.
•Ready-to-use cradle-to-gate inventory data for cemented carbides (WC-Co).•A few inputs and outputs dominate life cycle environmental impacts.•Recycling greatly reduce life cycle environmental impacts of WC-Co.•Typical non-Chinese production requires less energy than Chinese production.
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