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Ground-coupled heat pump (GCHP) systems can provide comfortable indoor environments, but also inevitably contribute to greenhouse gas emissions and other impacts on human health, ecosystems, and resources. Life cycle assessment (LCA) methodology has been widely adopted to estimate the environmental impacts associated with GCHP systems, with operational electricity consumption being the largest contributor among most categories. Given the data-intensive nature of LCA, operational electricity consumption should be prioritised to refine the accuracy of LCA results. Previous studies, however, have relied on static COP (Coefficient of Performance) and annual average data to obtain the environmental impacts and have disregarded the effect of long-term performance degradation caused by building thermal load imbalances. In this paper, to bridge this research gap, a dynamic operational environmental impact assessment (DOEIA) method was proposed to improve the precision of LCA results by incorporating higher temporal resolution data of electricity mix and real-time performance modelling of the reversible GCHP system. Impacts of different temporal resolutions (i.e. monthly, trimestral, and annual) on the accuracy of LCA results was examined and the operational performance degradation resulting from imbalanced building heating and cooling loads was considered. Results demonstrate that while performance degradation effects are evenly distributed across impact categories, gaps due to temporal resolutions vary significantly between different categories. Subsequent analysis of spatial variations in the latter further emphasises the importance of accounting for higher temporal resolutions. Finally, life cycle impact assessment (LCIA) results for reversible GCHP systems in different locations were obtained with the support of DOEIA method and the results underscore the necessity of a cleaner energy mix. The proposed DOEIA method can be applied to other energy systems for comparative analyses. It is replicable in other countries and regions and therefore is expected to provide methodological guidance for future decision-makers. • Development of a dynamic method to improve the accuracy of LCA of GCHP systems. • Evaluated long-term performance degradation and low-temporal resolution data effects. • Performance degradation affects categories consistently; low-resolution data varies. • Spatial analysis clarifies parameters affecting environmental impacts. • The proposed method is applicable to other energy systems for comparative analyses. [ABSTRACT FROM AUTHOR]

The battery electric vehicle (BEV) industry, commanding over half of the global market share in China, has garnered significant attention in response to escalating concerns about climate change. NCM (LiNi x Co y Mn z O 2) batteries, prized for their high energy density, are pivotal in this industry. However, their production relies on critical metals, posing environmental challenges. Recycling processes aim to address this issue by recovering critical metals from end-of-life batteries. The industry is updating from NCM 111 to NCM 811 batteries to enhance energy density and reduce costs, but the key factors influencing the material flows and environmental impacts remain uncertain. This paper aims to identify the key factors contributing to the potential differences in material flows and environmental impacts introduced by the NCM battery upgrading in China. Following the new energy vehicle sales projections in China until 2035, a dynamic material flow analysis was employed to calculate material demands, recovered amounts, and substitution rates for various upgrading scenarios. The study reveals that the majority of retired batteries until 2035 were sold between 2022 and 2029. Material substitution rates prove to be more sensitive to the upgrading scenario than the lifetime and growth rate of BEVs. Faster NCM 811 penetration results in over 2.5 times more saved cobalt demand compared to additional nickel demand. A life cycle assessment of NCM batteries reveals a 39% lower global warming impact for NCM 811 compared to NCM 111, highlighting environmental benefits from increased energy density and reduced cobalt consumption. The energy density improvement contributed 85%, while the alteration in material composition contributed 15% to the global warming reduction in NCM 811. Recycling emerges as a crucial strategy in mitigating environmental impacts across all categories, particularly addressing eutrophication, previously deemed challenging due to the difficulty in recovering Li 2 CO 3. [ABSTRACT FROM AUTHOR]

COVID–19 has disrupted human life considerably since the beginning of 2020. The transport sector is one of the most affected sector due to restrictions imposed to curb COVID–19 pandemic. This paper evaluates the environmental impacts of COVID–19 response scenarios using life cycle assessment approach. Six regions selected for the study are Australia, China, European Union (EU), India, United Kingdom (UK), and United States of America (USA). Data for vehicle population, vehicle kilometers travelled, fleet type, and fuel efficiency were used for 2015–2020. The environmental impacts were calculated for five scenarios; Baseline–2019, Business As Usual (BAU) and COVID–19 Response Scenario (CRS) for 2020 and 2030 namely, 2020–BAU, 2020–CRS, 2030–BAU, and 2030–CRS. The results indicate that COVID–19 occurrence and related response measures did not contribute to significant environment benefits in terms of Global Warming Potential (GWP) and other pollutants in short term and long term. This implies that although immediate reductions in emissions were observed in many studies, the long term effects were minimal due to irregular policies and unmanaged demand. Further, to achieve environment benefits sustained measures should be implemented in long term with proper planning and supporting infrastructure. Although electric vehicle strategies will provide benefits; emphasis on vehicle production and fuel production technologies is also needed to achieve the emission reduction targets. The findings are relevant for policy makers while devising policies to achieve the targets. • Vehicle stock will grow significantly in 2030 for developing countries • China's 2030 transport sector GWP will be highest, 1772 MT CO 2 eq, surpassing USA • Only USA showed reductions for all pollutants in 2030 COVID-19 response scenario • All countries had similar trends for most pollutants at different life cycle stages • COVID–19 occurrence didn't contribute to significant benefits in short & long term [ABSTRACT FROM AUTHOR]

The low price and excellent flexibility of plastic straws make them very popular, yet their short lifespan and improper disposal after use result in major resource waste and environmental burdens. To this end, paper straws and polylactic acid (PLA) straw alternatives have emerged on the market. Aiming to present a comparative sustainability study of drinking straws, this article provides a life cycle assessment of drinking straws made of polypropylene (PP), paper, and polylactic acid (PLA) based on Chinese context, as well as a scenario analysis of the availability of low-carbon electricity (LCE) and its recycling capacity (RC). The functional unit was set as a straw suitable for 500 ml milk tea cups, and the system boundary is from cradle to grave, including raw material preparation process, straw production process, usage process, waste process, transportation and recovery process. The comparative analysis revealed that the plastic straw alternative would not be superior in all indicators, but would lead to environmental problem-shifting, which will provide a basis for decision making and avoid bias caused by subjective choices. Scenario analysis shows that the synergistic effect of LCE and RC can minimize the environmental burden for paper straw, especially in terms of Primary Energy Demand (PED) which reduced by 27.9% with 100% RC and 50% LCE, and this is mainly due to RC. The findings of this work can offer theoretical justification, data references, and fresh perspectives for environmental evaluation of straws. [Display omitted] [ABSTRACT FROM AUTHOR]

Two economic activities have been integrated in southern Brazil: olive cultivation and sheep farming. The favorable edaphoclimatic conditions in the southern region for cultivating olive trees and cultural preferences for the consumption of sheep meat make this integration a valuable strategy. Considering that every activity causes environmental impact and the exploitation of natural resources, new systems that promote sustainable development and the efficient use of these resources become necessary. This paper presents the first study of the carbon footprint of the life cycle of integrating of sheep and olive farming, with the objective to build an inventory based on primary data collected on olive and sheep farms in Brazil, determine the carbon footprint of the conventional and integrated system and estimate the potential for mitigating GHG emissions. The evaluation was performed using the life cycle assessment (LCA) methodology. The study focuses on the detailed analysis of the processes and activities that are responsible for GHG emissions, including enteric methane emissions, methane emissions from manure management, emissions from nitrogen fertilizer use and limestone application and energy consumption. For this, two major scenarios were considered, the first centered around on the traditional olive cultivation and sheep farming systems individually, and the second involved their synergistic integration. The findings indicate that the conventional system is associated with a global warming impact of 6.8 kg CO 2 eq per liter olive oil and kg live weight. In contrast, the integrated system demonstrates a significant mitigation potential of 27.7%, resulting in a reduced global warming impact of 4.92 kg CO 2 eq. This advantage is a consequence of the synergy between the systems, as they now occupy the same area, which allows the sharing of agricultural activities and agrochemical inputs, in addition to optimizing nutrient recycling and complementing each other. Additionally, the results of a sensitivity analysis showed that enteric methane from sheep and the application of limestone to the soil are the most influential parameters on the carbon footprint, indicating that they are key parameters for the development of GHG mitigation strategies, some of which were discussed in the article. • First life cycle assessment of integration between olive and sheep farming in Brazil. • The inventory was constructed with primary data collected in situ. • The study assesses the carbon footprint of the olive and sheep farming system. • The results show environmental advantages of the integration of olive and sheep farming systems. [ABSTRACT FROM AUTHOR]

At present, the energy and environmental crisis is increasingly prominent, and how to solve the global energy and environmental problems is one of the challenges facing the world today. China is a major producer and consumer of organosilicon, so it is necessary to explore the stage of high energy consumption and high pollution in the organosilicon industrial chain. In 2022, the proportion of submerged arc furnaces of 25000 kVA and higher in China reached 40%. Further expansion of these furnaces in the future is inevitable. However, research on the life cycle assessment of organosilicon manufactured using large-capacity submerged arc furnaces is still blank.Therefore,in this paper, the life cycle assessment method is used to evaluate the synthesis process of chemical grade silicon-organosilicon monomer prepared by large capacity (33000 kVA) submerged arc furnace, and the dominant process in various environmental impacts is defined.At the same time, the measures to improve the production process of organosilicon monomer were put forward. In the production process of 1000 kg organosilicon monomer, global warming potential (GWP) contributed the most (73.43%) to the comprehensive environmental impact, followed by chronic public health impact (HTI, 10.55%). Energy consumption (EN) accounted for 8.50%, while resource consumption (RU) accounted for 7.43%. The contributions of other environmental factors were relatively small (0.09%).The energy consumption and environmental pollution in the production of organosilicon monomer can be reduced by strictly controlling the quality of raw materials into the furnace, using heat pump technology in the distillation unit, and comprehensively utilizing the heat of reaction by-products and steam condensate. [Display omitted] • This study is the first one in China to conduct LCA for the preparation of chemical grade silicon-organosilicon monomer synthesis process in 33000 kVA submerged arc furnace. It provides the best improvement suggestions for reducing the environmental load of the product life cycle process and achieving cleaner production. • In response to the national development policy of large-scale submerged arc furnace, the dominant process of preparing organosilicon monomer based on 33000 kva submerged arc furnace in various environmental impacts was clarified. • The main technical improvement directions are: Strictly control the quality of raw materials for submerged arc furnace; Strictly control the sulfur content and nitrogen content of carbonaceous reductant, and adopt the most suitable flue gas treatment technology route; Smelt with large submerged arc furnace; Use heat pump technology for distillation unit; Optimize the monomer synthesis device. [ABSTRACT FROM AUTHOR]

In machining processes, there are contradictions between high efficiency and environmentally-friendly machining. This indicated that there is a major potential for sustainable machining to both increase efficiency and protect ecological balance. For this, the employment of effective methods has become imperative to reduce resource use. In this way, the use of analysis and optimization tools to select the tool material, cutting parameters, cooling/lubrication conditions, etc., will be a benefit for minimizing waste without sacrificing efficiency. In the literature, researchers have used various methods to reveal the requirements of sustainability. However, reaching the concept of sustainable machining by using one more than technique confuses the readers. Therefore, it was deemed necessary to present and discuss the current methods, models and analyzes in a comprehensive review paper. In this context, this paper reviewed the previously published works, especially focusing on sustainability and energy consumption modeling methods in machining operations. At the end of the study, it was seen that LCA provides a systematic and quantitative view of the system and thus can act as a decision support tool. Moreover, it can give an idea to the manufacturers about the improvement of the process and the areas of innovation. However, the method has several disadvantages such as relatively expensive and specific software, obtaining inventory data, impractical to use, time-consuming and requires large amounts of data. Various mathematical models and algorithms have been developed to deal with the complex situations and offer a more practical use compared to LCA. However, it is difficult to state that clear results have been achieved thanks to these models. It was seen that in complex machining processes, only approximate results can be found with models, which leads to questioning the reliability of the models. [ABSTRACT FROM AUTHOR]

This paper reviews the published research pertaining to the use of superheated steam for carbon fibre reinforced polymer (CFRP) composite reclamation. Superheated steam has been used for this purpose for around a decade and was initially investigated to prevent the degradation of reclaimed fibres, which occurs during the oxidative char removal step of most pyrolysis-based reclamation techniques. The review evaluates the various methodologies employed with particular focus on the physical, mechanical, and chemical properties of the reclaimed fibres, and the environmental impact of using superheated steam for carbon fibre reclamation as determined by life cycle assessment. Superheated steam studies report recovering carbon fibres with retained tensile moduli of around 90%–100% and tensile strengths of 65%–100% when compared to virgin carbon fibres, however, when optimised it is shown that carbon fibres can be recovered with no loss in stiffness and strength. Most studies are still at laboratory- or pilot-scale, however, several companies are collaborating with researchers to investigate the potential of this reclamation method on a larger scale. Early analysis on the energy use of carbon fibre reclamation using superheated steam shows that energy savings of 25% could be made by recycling CFRP waste using superheated steam and using the recovered carbon fibres to displace virgin carbon fibres rather than landfilling and incinerating this waste. • Review of the developments pertaining to superheated steam use for carbon fibre reinforced polymer reclamation. • Superheated steam reclaimed carbon fibres retain tensile strengths of 65%–100% and tensile moduli of around 90%–100%. • Review of the life cycle assessment of superheated steam-based carbon fibre reinforced polymer reclamation. • Examples of superheated steam reclamation processes entering the pilot-plant/industrial phase. [ABSTRACT FROM AUTHOR]

China's growing capacity of bioethanol production renders the conversion of ethanol-to-jet fuel (ETJ) promising. However, ETJ studies are currently scarce in China. This study employed process simulation to model two novel ETJ processes that combined corn cob gasification, syngas-to-ethanol, and ethanol-to-jet fuel. This paper also discussed the other three ETJs, in which ethanol were obtained via direct-fermentation of corn, cassava, and corn cob, respectively. Life cycle assessment (LCA) was performed to evaluate energy consumption and greenhouse gas (GHG) emissions of ETJs in China. The results showed that the ETJ pathway, which included corn cob gasification plus fermentation, showed the least energy consumption and GHG emission, with 370.05 KJ/MJ jet fuel and 31.66 gCO 2 eq/MJ jet fuel, respectively. Sensitivity analysis was performed to identify parameters that had a significant impact on the results, and uncertainty analysis was implemented to check the reliability of the result. Further analysis revealed that cleaner electricity and heat production could effectively reduce the GHG emissions of the energy-intensive ETJs, with the highest reduction of 21.55%. Given that few life cycle assessments of ETJs in China have reported, this study can assist policy-makers to decide the path in which China's sustainable aviation fuel (SAF) should evolve. [Display omitted] • Life cycle analysis for 5 ethanol-to-jet fuels established toward China situation. • The process based on corn-cob-syngas fermentation showed the best carbon reduction. • Optimizing biomass and ethanol conversion could greatly reduce GHG emissions. • Electricity mixes highly impacted on the process based on corn-cob-syngas catalysis. • Life cycle results were mostly sensitive to the displacement allocation method. [ABSTRACT FROM AUTHOR]

The literature available on alternative fuel heavy-duty trucks often focuses on greenhouse gas emissions and total cost of ownership assessments, drawing an insightful but incomplete picture of the best solutions for each context. Using Iceland as case study, this paper attempts to provide a broader perspective by including energy security, technical feasibility and air pollutant emissions in the assessment. AFLEET and GREET are used to calculate the life cycle emissions and the total cost of ownership of 10 heavy-duty powertrains using representative vehicle categories in Iceland: regional and delivery trucks. The technical feasibility of battery-electric and hydrogen trucks is addressed in terms of battery/tank required capacity for representative fuel efficiency values, while the resources available in Iceland are used to determine the local fuel production capacity and the potential impact of each alternative fuel pathway on energy security. The results suggest that battery-electric trucks present the highest environmental and economic benefits, although the limited range of current battery technology implies a high penetration only in delivery trucks. Hydrogen and compressed natural gas pathways present attractive results for regional trucks, although their implementation is limited due to high life cycle costs and insufficient feedstock capacity. Renewable diesel stands out as a potential solution to fill the gap for regional trucks as it presents overall satisfactory results throughout all dimensions addressed. The results suggest that a 100% alternative fuel heavy-duty fleet energy demand could be met using local resources in Iceland. [Display omitted] • The transition towards alternative fuel heavy duty vehicles in Iceland is studied. • Nine alternative fuel heavy duty powertrains are assessed in LCA and TCO terms. • The link between alternative fuel production and energy security is discussed. • BEV stands out as the most attractive pathway for both vehicle categories. • Iceland could meet 100% of HDV energy demand using domestically produced fuels. [ABSTRACT FROM AUTHOR]

Eco-design that addresses the consumption of resources and energy, as well as pollution emissions from a product life-cycle perspective, is an effective way to solve environmental problems. However, the optimal eco-design solution is hardly generated in the conceptual design stage due to the complex association of the life cycle design information. To this end, this paper proposes a new eco-design model based on a life cycle integrated framework to effectively manage life cycle information in the conceptual design phase. In this work, (1) The life cycle-oriented model is proposed to integrate the product design information in terms of a systematic association mechanism between function, structure, material and process to construct the design space. (2) A life cycle design scenario-based similarity matching method is developed to support the environmental impact assessment of design options in the design space. (3) A hope tree-based heuristic search algorithm with the principle of minimizing environmental impact is proposed to efficiently obtain the eco-design solution. An application for eco-design of the lift equipment is given to demonstrate the capability of the proposed method. The results show that the environmental impact of the generated eco-design solution is improved by 19.48%, and the material and use stage has the highest environmental impact which accounts for 39.59% and 47.74% respectively. This work provides a targeted method for guiding designers to implement eco-design in the conceptual design phase through the life cycle. [Display omitted] • An integrated life cycle model is proposed to express the design information of function, structure, material and process. • A scenario-based similarity matching method is proposed to acquire the LCI for the design options. • Hope tree-based algorithm is used to efficiently obtain the optimal eco-design solution. [ABSTRACT FROM AUTHOR]

Despite the substantial effort on almost all levels during the last decades, the buildings' renovation rate needs to be at least doubled from the current 1% to meet ambitious energy efficiency goals. In the same way, the energy-intensive material replacement did not reach yet the desired grade in terms of sustainability measures and outlined goals heading to a low-carbon economy. This paper summarizes principles of sustainable development together with the current methodological framework relevant to the civil engineering and construction industry. The main part is devoted to the identification and understanding of principal factors preventing faster adoption of energy efficiency measures. High initial financial costs, investment risk over a long-term period, poor acceptance of sustainable measures, lack of information, and limited methodological framework for a reliable evaluation of environmental projects with the intergeneration context or understanding of externalities of human activities are identified as the main barriers to the sustainable building retrofits. These barriers are closely related each other and can be merged into several groups according to the stakeholders or scientific disciplines to amplify their primary impact. Notwithstanding, solution strategies based on narrow boundary conditions and limited multidisciplinary approach prevent substantial advances towards the sustainable building sector. In this regard, the major obstacles preventing the achievement of energy efficiency goals can be remedied by interdisciplinary cooperation. • Lacking multidisciplinary approach hinders sustainable measures adoption. • Limited public acceptance prevents a stronger political commitment. • Methods of social measures need to be studied for decision support. • Sustainable building industry transition is not a technical issue only. [ABSTRACT FROM AUTHOR]

Residential and commercial buildings consume around 40% of the total energy of the world. The building sector is also responsible for 30% of the global greenhouse gas emissions. There is an urgent need to assess the environmental carbon footprint (CFP) of global building industry. This study reviews the related studies and calculates the CFP of a residential building constructed in Turkey by considering the type of construction materials, energy consumption habits, maintenance and demolition stages in a 50 year of life cycle. The CFP of a common type of residential building constructed in Turkey found to be 48.87 kgCO 2 eq/m2/year. The CFP of structural elements used during the construction phase has been calculated to be 6.94 kgCO 2 eq/m2/year, which is about 14.21% of the total footprint. It is investigated that; the operational stage is the foremost contributor, representing 64.11% of CFP. The CO 2 emissions have been decreased by 38.05% by the implementation of basic methods. Unlike other studies, this paper revealed that the CFP from transportation of habitants is 6.5% more than the construction stage contributing 15.13% of overall emissions. The comparative studies of constructions in different countries show that CFP significantly depend on the behavioral factors of citizens of a country and the system boundaries selected. The results exposed that the effects of transportation should not be disregarded in the future studies. [Display omitted] • The total life cycle CFP of the building found to be 48.87 kgCO 2 eq/m2/year. • The CFP of construction materials is calculated to be 6.94 kgCO 2 eq/m2/year. • CFP from transportation of habitants is 6.5% more than the construction stage contributing 15.13% of overall emissions. • The daily energy use of the habitants is the main contributor to the CFP, representing the 64.11% of CFP. • The CFP of the building has been decreased by 38.05% by the implementation of low-carbon strategies. [ABSTRACT FROM AUTHOR]