Evaluating the cascading-use of wood furniture: How value-retention processes can contribute to material efficiency and circularity

As utilized technical products, durable wood furniture plays an important role in a future circular economy (CE). However, contemporary CE literature predominantly focuses on wood's biochemical properties and its potential as a consumable material within the bio-cycle. This perspective prevents meaningful consideration of CE strategies for the wood products sector, particularly for value-retention processes (VRPs), including reuse, repair, and refurbishment. We adapt and apply the VRP model introduced by the UN International Resource Panel (IRP) to wood furniture products to quantify select environmental benefits made possible through cascading-use, via VRPs (vs. new manufacturing). Unlike traditional life cycle assessment (LCA), this model accounts for impacts incurred and avoided through product life-extension and VRPs, relative to conventional systems of new manufacturing, disposal, and replacement. Three case studies of wood-based chairs are conducted to demonstrate this new application of the VRP model to compare the relative environmental impacts associated with wood furniture that is diverted to cascading-use, prior to recycling. In collaboration with industry partners, new material requirements (kg/unit), energy requirements (kWh/unit), emissions (kg CO2-e./unit), and waste generation (kg/unit) were calculated for newly manufactured chairs (OEM new) and subsequent cascading-use via reuse, repair, and refurbishment. The differing degrees of environmental impact avoidance and material efficiency are presented for each case study product and VRP, to provoke discussion and future research regarding the effective and optimal utilization of technical, durable wooden furniture within a CE.     

Environmental Life Cycle Assessment of a Swedish Dissolving Pulp Mill Integrated Biorefinery

The pulp industry plays an important role in the structure of the European economy and society. The production of pulp has been traditionally considered an important source of pollution due to the use of large amounts of chemicals, fuels, and water and its intensive energy consumption. Currently, this situation is changing due to the potential use of biomass to produce value‐added products, which minimizes environmental impacts and increases sustainability. This article uses life cycle assessment (LCA) to identify and quantify the environmental impacts associated with a Swedish softwood‐based biorefinery where total chlorine‐free (TCF) dissolving cellulose is produced together with ethanol and lignosulfonates. The system was defined according to a cradle‐to‐gate perspective—that is to say, from forest activities to the output of the biorefinery mill. According to the results, forest activities associated with the production of soft roundwood play a minor role in all the environmental impact categories under study. In contrast, the production of chemicals consumed in the cooking and bleaching stages, the sludge treatment generated in the wastewater treatment plant, and the on‐site energy production system were identified as the elements that negatively contribute the most to all impact categories. The production of steam from biorefinery wastes, biogas, and methanol in external boilers reduces the environmental impact in all categories. Specific actions associated with the reuse of wastes and improved gas treatment systems would improve the environmental profile of this production activity.     

Setting Priorities within Product-Oriented Environmental Policy

To focus Danish product‐oriented environmental policy, a study applying extended input‐output analysis has been performed, identifying the most important product groups from an environmental perspective. The environmental impacts are analyzed from three different perspectives—the supply perspective, the consumption perspective, and the process perspective—differing primarily in their system delimitation. The top ten environmentally most important product groups (out of 138 industry products and 98 final consumption groups) are listed for each of the three perspectives, using both total environmental impact and environmental impact intensity as ranking principles. The study covers all substances that contribute significantly to the environmental impact categories of global warming, ozone depletion, acidification, nutrient enrichment, photochemical ozone formation, ecotoxicity, human toxicity, and nature occupation. The differences in results between the three perspectives are elaborated and their policy relevance discussed. The top ten product groups account for a surprisingly large share of the total environmental impact of Danish production and consumption (up to 45%, depending upon the perspective). This implies that product‐oriented environmental policy may achieve large improvements by focusing on a rather small number of product groups. Both imported products and products produced for export in general cause more environmental impact than products produced in Denmark for the Danish market. Especially noticeable are the export of meat and ship transport. This leads to the recommendation to include specific policy measures targeting both foreign producers and foreign markets. Because of its relatively large input of labor, public consumption is found to have a much smaller environmental impact intensity than private consumption. The results confirm results of other similar studies, but are more detailed and have lower uncertainty, due to a number of improvements in data and methodology. A short presentation of the methodology is provided as background information, although this is not the main focus of this article.     

Environmental Impact Assessment of Wood Use in Japan through 2050 Using Material Flow Analysis and Life Cycle Assessment

In this study, we used material flow analysis and life cycle assessment to quantify the environmental impacts and impact reductions related to wood consumption in Japan from 1970 to 2013. We then conducted future projections of the impacts and reductions until 2050 based on multiple future scenarios of domestic forestry, wood, and energy use. An impact assessment method involving characterization, damage assessment, and integration with a monetary unit was used, and the results were expressed in Japanese yen (JPY). We found that environmental impacts from paper consumption, such as climate change and urban air pollution, were significant and accounted for 56% to 83% of the total environmental impacts between 1970 and 2013. Therefore, reductions of greenhouse gas, nitrogen oxide, and sulfur oxide emissions from paper production would be an effective measure to reduce the overall environmental impacts. An increase in wood use for building construction, civil engineering, furniture materials, and energy production could lead to reductions of environmental impacts (via carbon storage, material substitution, and fuel substitution) amounting to 357 billion JPY in 2050, which is equivalent to 168% of the 2013 levels. Particularly, substitution of nonwooden materials, such as cement, concrete, and steel, with wood products in building construction could significantly contribute to impact reductions. Although an increase of wood consumption could reduce environmental impacts, such as climate change, resource consumption, and urban air pollution, increased wood consumption would also be associated with land‐use impacts. Therefore, minimizing land transformations from forest to barren land will be important.     

Are future recycling benefits misleading? Prospective life cycle assessment of lithium-ion batteries

Life cycle assessment (LCA) quantifies the whole-life environmental impacts of products and is essential for helping policymakers and manufacturers transition toward sustainable practices. However, typical LCA estimates future recycling benefits as if it happens today. For long-lived products such as lithium-ion batteries, this may be misleading since there is a considerable time gap between production and recycling. To explore this temporal mismatch problem, we apply future electricity scenarios from an integrated assessment model—IMAGE—using “premise” in Brightway2 to conduct a prospective LCA (pLCA) on the global warming potential of six battery chemistries and four recycling routes. We find that by 2050, electricity decarbonization under an RCP2.6 scenario mitigates production impacts by 57%, so to reach zero-carbon batteries it is important to decarbonize upstream heat, fuels, and direct emissions. For the best battery recycling case, data for 2020 gives a net recycling benefit of −22 kg CO₂e kWh⁻¹ which reduces the net impact of production and recycling from 71 to 49 kg CO₂e kWh⁻¹. However, for recycling in 2040 with decarbonized electricity, net recycling benefits would be nearly 75% lower (−6 kg CO₂e kWh⁻¹), giving a net impact of 65 kg CO₂e kWh⁻¹. This is because materials recycled in the future substitute lower-impact processes due to expected electricity decarbonization. Hence, more focus should be placed on mitigating production impacts today instead of relying on future recycling. These findings demonstrate the importance of pLCA in tackling problems such as temporal mismatch that are difficult to capture in typical LCA.     

Environmental Life Cycle Assessment of a Canned Sardine Product from Portugal

This study aims to assess the environmental impacts of canned sardines in olive oil, by considering fishing, processing, and packaging, using life cycle assessment (LCA) methodology. The case study concerns a product of a canning factory based in Portugal and packed in aluminum cans. It is the first LCA of a processed seafood product made with the traditional canning method. The production of both cans and olive oil are the most important process in the considered impact categories. The production of olives contributes to the high environmental load of olive oil, related to cultivation and harvesting phases. The production of aluminum cans is the most significant process for all impact categories, except ozone depletion potential and eutrophication potential, resulting from the high energy demand and the extraction of raw materials. To compare to other sardine products consumed in Portugal, such as frozen and fresh sardines, transport to the wholesaler and store was added. The environmental cost of canned sardines is almost seven times higher per kilogram of edible product. The main action to optimize the environmental performance of canned sardines is therefore to replace the packaging and diminish the olive oil losses as much as possible. Greenhouse gas emissions are reduced by half when plastic packaging is considered rather than aluminum. Frozen and fresh sardines represent much lower environmental impacts than canned sardines. Nevertheless, when other sardine products are not possible, it becomes feasible to use sardines for human consumption, preventing them from being wasted or used suboptimally as feed.     

Environmental Implications of Future Demand Scenarios for Metals: Methodology and Application to the Case of Seven Major Metals

In this paper, we develop a method to assess the environmental impacts of metal scenarios. The method is life cycle based, but enables forward looking and upscaling. The method aims at translating metal demand scenarios into technology‐specific supply scenarios, necessary to make the translation into environmental impacts. To illustrate the different steps of the methodology, we apply it to the case of seven major metals. Demand scenarios for seven major metals are taken from literature. We translate those into technology‐specific supply scenarios, and future time series of environmental impacts are specified including recycling rates, energy system transformation, efficiency improvement, and ore grade decline. We show that the method is applicable and may lead to relevant and, despite many uncertainties, fairly robust results. The projections show that the environmental impacts related to metal production are expected to increase steeply. Iron is responsible for the majority of impacts and emissions are relatively unaffected by changes in the production and energy system. For the other metals, the energy transition may have substantial benefits. By far, the most effective option for all metals appears to be to increase the share of secondary production. This would reduce emissions, but is expected to become effective only in the second half of the twenty‐first century. The circular economy agenda for metals is therefore a long‐term agenda, similar to climate change: Action must be taken soon while benefits will become apparent only at the long term.     

Technological Change and the Environmental Impacts of Food Production and Consumption: The Case of the UK Yogurt Industry

This article examines the changing food production and consumption system of yogurt in the United Kingdom, focusing on the environmental impact of the yogurt processing stage from a technological perspective. Based on interviews with key industry stakeholders, we describe the evolution of the yogurt industry since the 1950s, characterized by a shift toward industrialized mass production and increased product diversity. We explain how new technologies, sociopolitical trends, and industrial strategies have shaped the evolution of the industry over this period. Moreover, we argue that the environmental impact of the current yogurt production and consumption system has been determined to a large extent by technological change. The article explores the future of the yogurt production and consumption system, considering the environmental implications of increased production of more differentiated yogurt products and how technological change may mitigate some of those impacts. The analysis reveals that to appreciate the environmental impact of the yogurt industry, policy makers should not focus simply on the primary stage of production but on all stages of the yogurt production and consumption system. Minimizing waste and improving resource efficiency at the yogurt processing stage are found to be particularly important. Transformation to an alternative yogurt production and consumption system with substantially lower environmental impacts requires significant commitment to change across the industry and the wider sociotechnical landscape.     

Can smart factories bring environmental benefits to their products?: A case study of household refrigerators

Smart factories have been widely adopted as a new manufacturing paradigm, in which the state‐of‐the‐art technologies are introduced to improve relevant processes. Yet, whether smart factories affect the environmental performance remains unknown. In this article, we examine the environmental performance of a smart refrigerator factory by comparing the environmental impacts of its product to a similar model that is produced in a traditional fashion. This article quantifies and verifies the theoretically predicted impacts of this smart factory on the individual processes. Though the overall differences in the two models are quite minor, we find that this smart factory can notably reduce the values of most impact categories associated with the parts and refrigerator production; the reduction in the value of climate change is 33%. Owing to higher material efficiency—raw material savings in this smart factory contributes to the greatest reductions in most categorized impacts—the contribution to the reduction of climate change is 39%. Yet, all categorized impacts of procurement and delivery are increased due to product personalization and direct delivery. The results of sensitivity analysis show that promoting product modularity, adopting clean energy such as wind power can further improve the environmental performance of the selected refrigerator. The introduction of auxiliary equipment and systems slightly increases the value of each category; yet their impacts are negligible compared to their benefits as facilitating production efficiency. Based on the quantitative results, recommendations are given to improve the environmental performance of smart factory, including optimizing current strategies and promoting horizontal and end‐to‐end integration.     

Comparative life cycle assessment of re-use and replacement for video projectors

Purpose

The current focus of environmental legislation for energy-using products is an efficient energy consumption in the use stage. However, the production and waste treatment of electronic products are also related to environmental impacts in terms of declining metal resources and growing waste streams. This paper investigates the environmental impacts of life time extension versus energy efficiency for the product group video projector using life cycle assessment (LCA).

Methods

The product under study was an average video projector based on three LCD projectors. The studied systems included two possibilities after a regular first usage period: reconditioning for a second use or replacement by a primary successor with an energy efficiency increase of 5 and 10%. All impacts addressed were accounted using the ReCiPe 2008 method. The impact contribution of projector components was identified at midpoint and endpoint levels, while life cycle impacts were calculated with a focus on three impact categories. Furthermore, the amortization period of production emissions was quantified.

Results and discussion

LCA results showed that the use stage dominates life cycle impacts of the global warming potential and primary energy demand. For the metal depletion potential, the production stage accounts for most of the total life cycle load. The highest shares in production emissions were identified for electronic components, namely printed wired boards and integrated circuits. Reconditioning and reuse of a secondary projector resulted in minor environmental impacts compared to the replacement and use of a primary projector with an energy efficiency increase of 5%. The saving potential of the primary energy demand is higher only in the case of a 10% more efficient device as compared to the secondary projector.

Conclusions

The study concluded that production emissions and their amortization period are relevant factors offsetting any environmentally beneficial measures applied during the use phase. The study suggests that life time extension of video projectors can provide higher environmental improvement potentials, while energy efficiency increase during usage is less beneficial, given that major improvements in energy efficiency do not occur. Recommendations are valid for this particular case study. The study suggests that the current focus of mandatory product requirements for energy-using products on energy efficiency increase should be extended to measures of life time extension in order to serve the intent of an integrated product policy.

     

Evaluating the environmental performance of producing soil and surfaces through industrial symbiosis

Industrial symbiosis (IS), where different entities collaborate in the management of energy, utilities, materials, or services, has been identified as an approach to improve resource efficiency and circularity in industry. This article assesses the environmental performance of an IS network with firms involved in waste management, soil, surfaces, paper, lumber, and energy. The aim is to highlight the environmental performance of an IS network and pay particular attention to the improved performance for products in the IS network. Life cycle assessment is used to compare the current IS network with a reference scenario and a potential future development. The results suggest that there are significant benefits from the IS network. Large reductions in greenhouse gas (GHG) emissions and abiotic resource depletion were identified. Furthermore, large reductions in local impacts, namely eutrophication and acidification impacts are illustrated. It was shown that all firms in the network benefit from the synergies involved, with a large share of the benefits stemming from the facilitated exchanges with the waste management company. The replacement of conventional products and energy streams with bio‐based counterparts from within the network is of significant importance. Finally, the results point to the importance of the facilitation of by‐product synergies, and the significant value this creates in the region, with large potential to improve the environmental performance of firms and their products.     

Land‐use strategies to balance livestock production,biodiversity conservation and carbon storage in Yucatán,Mexico

Balancing the production of food, particularly meat, with preserving biodiversity and maintaining ecosystem services is a major societal challenge. Research into the contrasting strategies of land sparing and land sharing has suggested that land sparing—combining high‐yield agriculture with the protection or restoration of natural habitats on nonfarmed land—will have lower environmental impacts than other strategies. Ecosystems with long histories of habitat disturbance, however, could be resilient to low‐yield agriculture and thus fare better under land sharing. Using a wider suite of species (birds, dung beetles and trees) and a wider range of livestock‐production systems than previous studies, we investigated the probable impacts of different land‐use strategies on biodiversity and aboveground carbon stocks in the Yucatán Peninsula, Mexico—a region with a long history of habitat disturbance. By modelling the production of multiple products from interdependent land uses, we found that land sparing would allow larger estimated populations of most species and larger carbon stocks to persist than would land sharing or any intermediate strategy. This result held across all agricultural production targets despite the history of disturbance and despite species richness in low‐ and medium‐yielding agriculture being not much lower than that in natural habitats. This highlights the importance, in evaluating the biodiversity impacts of land use, of measuring population densities of individual species, rather than simple species richness. The benefits of land sparing for both biodiversity and carbon storage suggest that safeguarding natural habitats for biodiversity protection and carbon storage alongside promoting areas of high‐yield cattle production would be desirable. However, delivering such landscapes will probably require the explicit linkage of livestock yield increases with habitat protection or restoration, as well as a deeper understanding of the long‐term sustainability of yields, and research into how other societal outcomes vary across land‐use strategies.     

Steel’s recyclability: demonstrating the benefits of recycling steel to achieve a circular economy

Purpose

In a world where the population is expected to peak at around 9 billion people in the next 30 to 40 years, carefully managing our finite natural resources is becoming critical. We must abandon the outdated ‘take, make, consume and dispose’ mentality and move toward a circular economy model for optimal resource efficiency. Products must be designed for reuse and remanufacturing, which would reduce significant costs in terms of energy and natural resources.

Methods

To measure progress in achieving a circular economy, we need a life cycle approach that measures the social, economic and environmental impact of a product throughout its full life cycle—from raw material extraction to end-of-life (EoL) recycling or disposal. Life cycle thinking must become a key requirement for all manufacturing decisions, ensuring that the most appropriate material is chosen for the specific application, considering all aspects of a products’ life. The steel industry has been developing LCI data for 20 years. This is used to assess a product’s environmental performance from steel production to steel recycling at end-of-life. The steel industry has developed a methodology to show the benefits of using recycled steel to make new products. Using recycled materials also carries an embodied burden that should be considered when undertaking a full LCA.

Results and discussion

The recycling methodology is in accordance with ISO 14040/44:2006 and considers the environmental burden of using steel scrap and the benefit of scrap recycling from end-of-life products. It considers the recycling of scrap into new steel as closed material loop recycling, and thus, recycling steel scrap avoids the production of primary steel. The methodology developed shows that for every 1 kg of steel scrap that is recycled at the end of the products life, a saving of 1.5 kg CO₂-e emissions, 13.4 MJ primary energy and 1.4 kg iron ore can be achieved. This equates to 73, 64 and 90 %, respectively, when compared to 100 % primary production.

Conclusions

Incorporating this recycling methodology into a full LCA demonstrates how the steel industry is an integral part of the circular economy model which promotes zero waste; a reduction in the amount of materials used and encourages the reuse and recycling of materials.

     

Environmental payback periods of reusable alternatives to single-use plastic kitchenware products

Purpose

Many consumers are transitioning away from single-use plastic products and turning to reusable alternatives. Oftentimes, this change is being made with the assumption that these alternatives have fewer environmental impacts; however, reusable products are frequently made from more environmentally intensive materials and have use phase impacts. This study used LCA to examine the GWP, water consumption, and primary nonrenewable energy use associated with reusable alternatives for single-use plastic kitchenware products and determined environmental payback periods.

Methods

The environmental impacts for each reusable alternative are calculated on the functional units of 1 use, 1 year (5 uses/week), and 5 years (5 uses/week). Payback periods are calculated for each reusable alternative and defined as the number of times a consumer must reuse an alternative in order for the environmental impact per use to be equivalent to the environmental impact for the single-use product. The research explored the sensitivity of the results to different consumer washing and reuse behaviors, as well as local conditions such as overall transportation distances and the carbon intensity of different electricity grids. Product types studied included straws (4 reusable, 2 single-use), sandwich storage (2 reusable, 3 single-use), coffee cups (3 reusable, 2 single-use), and forks (1 single-use, 3 reusable).

Results and discussion

Environmental impacts associated with the reusable alternatives were highly dependent on the use phase due to dishwashing, making payback period sensitive to washing frequency and method, and for GWP, carbon intensity of the energy grid (used for water heating). For single-use products, the material/manufacturing phase was the largest contributor to overall impacts. It was found that nine of the twelve reusable alternatives were able to breakeven in all three environmental indicators. The coffee cup product type was the only product type to have one reusable alternative, the ceramic mug, and have the shortest payback period for all three impact categories. Both the bamboo straw and beeswax wrap were unable to breakeven in any scenario due to high use phase impacts from manual washing.

Conclusions

The research found that reusable alternatives can payback the environmental impacts of GWP, water consumption, and energy use associated with their more resource intensive materials, but it is dependent on number of uses, consumer behavior, and for GWP, carbon intensity of the energy grid. A key takeaway is that consumer behavior and use patterns influence the ultimate environmental impact of reusable kitchenware products.

Recommendations

Some recommendations for consumers looking to reduce the overall impact of kitchenware products include the following:

1. 1)

   Not always assuming reusable is the best option.

2. 2)

   Extending product lifetime.

3. 3)

   Researching which reusable option has the lowest impact.

4. 4)

   Following best practice washing behaviors.

5. 5)

   Not washing products after every use.

6. 6)

   Advocating for integration of renewables into the local energy grid.

7. 7)

   Reducing consumption of these product types (reusable or single-use).

     

Life Cycle Assessment of Novel Aircraft Interior Panels Made from Renewable or Recyclable Polymers with Natural Fiber Reinforcements and Non‐Halogenated Flame Retardants

A comprehensive life cycle assessment of panels for aircraft interiors was conducted, including both a conventional glass fiber‐reinforced panel and different novel sustainable panels. The conventional panel is made of a glass fiber‐reinforced thermoset composite with halogenated flame retardant, whereas the sustainable panels are made of renewable or recyclable polymers, natural fiber reinforcements, and nonhalogenated flame retardants. Four different sustainable panels were investigated: a geopolymer‐based panel; a linseed‐oil–based biopolymer panel; and two thermoplastic panels, one with polypropylene (PP) and another with polylactic acid (PLA). All of the sustainable panels were developed to fulfil fire resistance requirements and to be lighter than the conventional panels in order to reduce fuel consumption and air pollutant emissions from the aircraft. The environmental impacts associated with energy consumption and air emissions were assessed, as well as other environmental impacts resulting from the extraction and processing of materials, transportation of materials and waste, panel manufacturing, use, maintenance, and end of life (EoL). All the sustainable panels showed better environmental performance than the conventional panel. The overall impacts of the sustainable panels were offset by the environmental benefits in the use stage attributed to weight reduction. One square meter of the novel panels could save to 6,000 kilograms of carbon dioxide equivalents. The break‐even point (in months) at which the use of sustainable panels would yield an environmental benefit relative to the impacts arising in production and EoL was as follows: 1.2 for the geopolymer panel; 1.7 for the biopolymer panel; 10.4 for the PLA panel; and 54.5 for the PP panel.     

可持续消费的内涵及研究进展——产业生态学视角

生产和消费是产生诸多环境问题的根本原因,而可持续生产和消费则是实现可持续发展的根本途径。基于产业生态学视角,界定了可持续消费的定义及内涵,认为可持续消费首先须符合代内公平、代际公平和资源能源永续合理利用等可持续理念;其次辨识了可持续消费研究依次经历关注消费者行为直接环境影响、关注产品和服务生命周期环境影响到关注消费者责任3个阶段;最后结合我国城市化、工业化背景,提出我国可持续消费研究应该以城市居民为重点、加强生命周期数据库建设和内注重可持续生产等建议。     

Assessing the Replacement of Electrical Home Appliances for the Environment

To evaluate whether replacing an existing product with a new, more energy‐efficient product is environmentally preferable, we used an assessment approach based on life cycle assessment. With this approach, consumers can assess various replacement products, including products of different sizes or environmental performance in addition to consideration of various conditions of product use. The approach utilizes a diagram in which replacement conditions of products are compared with iso‐environmental‐load lines to determine the appropriateness of replacement. The approach also allows the assessment of energy and resource consumption and environmental impacts not only during the use stage, but also at other product stages. Iso‐environmental‐load lines to assess delayed replacement were also examined and derived. We then applied the approach in a case study of energy consumption by replacing three types of electric home appliances in Japan: TVs, air conditioners, and refrigerators. The results of assessment showed that replacing refrigerators after 8–10 years of use was preferable even if the replacement product was larger. The appropriateness of replacing TVs and air conditioners based on energy consumption depended on the replacement product and on the duration of daily use, and in several cases, delayed replacement was preferable. Replacement of air conditioners after 8–10 years of use was not preferable if the consumer already owned the most energy‐efficient product at the time of the purchase. The necessity of accounting for a variety of available replacement products was confirmed.     

A Market‐Based Framework for Quantifying Displaced Production from Recycling or Reuse

The most significant environmental benefit of recycling or reusing a wide range of products and materials is typically the potential to displace primary material production; lack of displacement significantly reduces the environmental benefits of these activities. Because no consensus method to estimate displacement rate has emerged, environmental assessments have tended to assume that displacement occurs on a one‐to‐one basis. However, displaced production is a complex phenomenon governed primarily by market mechanisms, rather than physical relationships. This article advances the understanding of displacement by presenting a market‐based framework describing the displacement relationship and a methodology for quantifying displacement rate based on partial equilibrium modeling. Using this methodology, a general symbolic equation for displacement rate after an increase in recycling is derived. The model highlights the market mechanisms that govern displaced production and identifies five price response parameters that affect displacement rate. Results suggest that one‐to‐one displacement occurs only under specific parameter restrictions that are unlikely in competitive commodity markets, but zero displacement is possible if secondary materials are poor substitutes for primary materials; displacement is likely to be reduced if secondary materials have inferior technical properties. The presented methodology can be generally applied to any system in which recycled or reused materials are substitutes or complements for primary materials. Implications for improving recycling and reuse efficacy and environmental assessment methodology are discussed, and suggestions are presented for expanding the displacement methodology in future research.     

Environmental trade-offs across cascading lithium-ion battery life cycles

Purpose

The purpose of this study was to analyze the environmental trade-offs of cascading reuse of electric vehicle (EV) lithium-ion batteries (LIBs) in stationary energy storage at automotive end-of-life.

Methods

Two systems were jointly analyzed to address the consideration of stakeholder groups corresponding to both first (EV) and second life (stationary energy storage) battery applications. The environmental feasibility criterion was defined by an equivalent-functionality lead-acid (PbA) battery. A critical methodological challenge addressed was the allocation of environmental impacts associated with producing LIBs across the EV and stationary use systems. The model also tested sensitivity to parameters such as the fraction of battery cells viable for reuse, service life of refurbished cells, and PbA battery efficiency.

Results and discussion

From the perspective of EV applications, cascading reuse of an LIB in stationary energy storage can reduce net cumulative energy demand and global warming potential by 15 % under conservative estimates and by as much as 70 % in ideal refurbishment and reuse conditions. When post-EV LIB cells were compared directly to a new PbA system for stationary energy storage, the reused cells generally had lower environmental impacts, except in scenarios where very few of the initial battery cells and modules could be reused and where reliability was low (e.g., life span of 1 year or less) in the secondary application.

Conclusions

These findings demonstrate that EV LIB reuse in stationary application has the potential for dual benefit—both from the perspective of offsetting initial manufacturing impacts by extending battery life span as well as avoiding production and use of a less-efficient PbA system. It is concluded that reuse decisions and diversion of EV LIBs toward suitable stationary applications can be based on life cycle centric studies. However, technical feasibility of these systems must still be evaluated, particularly with respect to the ability to rapidly analyze the reliability of EV LIB cells, modules, or packs for refurbishment and reuse in secondary applications.

     

Life cycle assessment of automotive lightweighting through polymers under US boundary conditions

Purpose

In the transportation sector, reducing vehicle weight is a cornerstone strategy to improve the fuel economy and energy efficiency of road vehicles. This study investigated the environmental implications of lightweighting two automotive parts (Ford Taurus front end bolster, Chevrolet Trailblazer/GMC Envoy assist step) using glass-fiber reinforced polymers (GFRP) instead of steel alloys.

Methods

The cradle-to-grave life cycle assessments (LCAs) for these studies consider a total service life of 150,000 miles for two applications: a 46 % lighter GFRP bolster on the 2010 Ford Taurus that replaced the 2008 steel and GFRP bolster, and a 51 % lighter GFRP running board for the 2007 Chevrolet Trailblazer/GMC Envoy that replaced the previous steel running board including its polymer fasteners. The life cycle stages in these critically reviewed and ISO-compliant LCA studies include the production of upstream materials and energy, product manufacturing, use, and the end-of-life treatment for all materials throughout the life cycle.

Results and discussion

The results show that the lighter GFRP products performed better than the steel products for global warming potential and primary energy demand for both case studies. In addition, the GFRP bolster performed better for acidification potential. The savings of fuel combustion and production during the use stage of a vehicle far outweigh the environmental impacts of manufacturing or end-of-life. An even greater benefit would be possible if the total weight reduction in the vehicle would be high enough to allow for the reduction of engine displacement or an elongation of gear ratio while maintaining constant vehicle dynamics. These so-called secondary measures allow the fuel savings per unit of mass to be more than doubled and are able to offset the slightly higher acidification potential of the GFRP running board which occurs when only the mass-induced fuel savings are considered.

Conclusions

The lightweight GFRP components are shown to outperform their steel counterparts over the full life cycle mainly due to the reduced fuel consumption of the vehicle in the use phase. To harvest the benefits of light weighting to their full extent, it is recommended that the sum of all mass reductions in the design process be monitored and, whenever feasible, invested into fuel economy by adapting the drive train while maintaining constant vehicle performance rather than leveraging the weight reduction to improve vehicle dynamics.