Symposium ES13—Materials Selection and Design—A Tool to Enable Sustainable Materials Development and a Reduced Materials Footprint

Circular Economy can be facilitated and accelerated by ensuring that the products we design and manufacture can be disassembled, repaired, recovered and reused. In order to achieve such a state requires actions in three areas: Education; Policy; and Innovation. Each of these areas will be discussed in some detail along with a presentation of case studies in transportation, electronics, energy storage, and packaging industries.

Green Electronics Council (GEC) is a mission-driven 501c(4) non-profit that collaborates to achieve a world in which only sustainable IT products are designed, manufactured, and purchased. Founded over 10 years ago to manage EPEAT, the leading global ecolabel for IT products, GEC advocates for sustainable IT by acting as the fulcrum point between those who buy (institutional purchasers) and those who make (information technology brands). EPEAT is a powerful way for institutional purchasers to “move the needle” towards a more sustainable world through their purchases of EPEAT registered computers & displays, mobile phones, servers, imaging equipment and televisions.
As a Type 1 ecolabel, EPEAT adopts criteria developed by organizations that adhere to ISO 14024 for Type 1 Ecolabels. GEC has an innovative new approach, the Dynamic Standards Development Process (DSDP), to developing environmental and social criteria for the EPEAT ecolabel. GEC’s Dynamic Standards Development Process (DSDP) is a new way of implementing a balanced voluntary consensus process to develop criteria. The DSDP begins with a State of Sustainability Research Packet that identifies priority environmental and social impacts within a product category. It then employs a modular approach to developing criteria to address those priority impacts. This modular approach allows relevant stakeholders to only have to spend time when there are criteria discussions relevant to their expertise. This allows for more effective and efficient engagement of organizations, especially those with limited resources. The DSDP also recognizes the importance of keeping EPEAT criteria relevant, as well as reflect market innovation, so the process relies on continuous maintenance of criteria.
EPEAT environmental and social criteria span the entire lifecycle of an electronic product, starting with the supply chain, and including materials selection, product design for recycling and reuse as well as responsible management at end of life. This presentation will describe GEC’s Dynamic Standards Development Process (DSDP) and the impact it can have on the design of electronic products, especially the choice of materials.

This tutorial will present three tools, GreenScreen for Safer Chemicals, Plastics Scorecard, and Chemical Footprint Project, and examples of their application for measuring the chemical footprint of materials and products. Chemical footprinting is the process of measuring chemicals of high concern in products and supply chains. GreenScreen provides a framework for both identifying chemicals of high concern and safer chemicals. Chemical Footprint Project specifies how to aggregate chemical of high concern data from products to the organizational level. Plastics Scorecard applies GreenScreen to measure the chemical footprint of plastic materials. This tutorial will detail examples of how companies and standards use GreenScreen to identify chemicals of high concern and safer chemicals, and how companies use Chemical Footprint Project to calculate their chemical footprint, quantify their baseline use of chemicals, and report reductions in their chemical footprint.

Metal recovery from electronic product is currently focused on high-volume metals that are easily recoverable and on low-volume, high-value precious metals. Current and future electronics will increasingly contain small quantities of materials which are not recovered in today’s recycling infrastructure. These materials include rare earth elements that are critical to today’s technology-driven society due to their importance to clean energy as well as the risk associated with their near-monopolistic supply. In this talk, an iNEMI (the International Electronics Manufacturing Initiative) project will be discussed on value recovery from hard disk drives that include critical materials. Demonstration projects were completed on direct reuse of entire hard drive, direct reuse of voice coil magnet assemblies, transformation of used rare earth magnets into “new” magnets, and production of rare earth oxide from shredded hard drives. The relevant life cycle inventory data were collected from project participants across industries and national laboratories to perform life cycle assessment. Accordingly, the environmental impacts were quantified for each recovery pathway and were compared with the virgin production impacts. The study also identified the environmental hotspots of each technology, highlighting the future work directions. The ultimate goal of this research is to support closing the material loop, reducing solid waste, and aligning industry with circular economy.

Implementing a Circular Economy results in major changes across product life cycles, including new business models, advanced remanufacturing and recycling processes, but might also involve a change of product designs. On the example of circular design trends of electronics products apparent material trends will be explained.
Modularity of products is one such design trend, which is supposed to facilitate reparability, recyclability, and/or upgradeability. However, modularity requires some design changes. In case of mobile information and communication technology, such as smartphones or tablet computers, the most evident design change is the need for connectors to provide mechanical and electrical contact between individual modules. Depending on the nature and use scenario of a connector reliability, robustness, wear resistance and non-reactive surfaces are required. Gold is the material of choice for such interfaces. In recent years the amount of gold used in electronics decreased, now with emerging modularity among ICT devices gold as a material with a high environmental impact might return into devices in larger amounts. For reversible mechanical fasteners a broader range of technologies might be employed, frequently magnets are proposed as a simple and robust option. To achieve strong magnetic forces rare earth elements are used, mainly neodymium or other critical raw materials, such as cobalt. Rare earth elements are not yet properly recovered from waste electrical and electronics equipment, thus modularity might even contradict better recyclability. The presentation will explain different modularity approaches for smartphones, some of these being already available in the market others are still in a conceptual phase. This variety of modularity approaches is related to different value propositions, thus leading also to a broader range of modularity archetypes. Analyzing technologies for modularity leads to a group of “Modularity Materials”, which are essential for such circular design approaches, but at the same time are among those materials with a large environmental footprint or limited recyclability. Furthermore, some standard materials are likely used more excessively, such as module housing or larger printed circuit boards to accommodate for on-board connectors. A Life Cycle Assessment of a modular smartphone shows a roughly 10% higher environmental life cycle impact compared to a conventional design. This needs to be compensated by reaping the Circular Economy benefits of a modular design, i.e. higher likeliness of getting a broken device repaired, extending the lifetime through hardware upgrades and refurbishment. The Life Cycle Assessment of the Fairphone 2 has shown, that a lifetime extension from 3 to 5 years leads to a significantly lower environmental impact despite the use of “modularity materials”. Consequently modularity is an appropriate approach for a Circular Design, but the user is key for a materialization of the theoretical benefits.
With a detailed view on such correlations the presentation gives a sound overview of trade-offs between different Circular Economy strategies. This research facilitates the understanding of future material trends in smart mobile devices and paves the way to improve the whole product eco-system for lower total environmental impacts.

The research presented in this paper is an outcome of the project sustainablySMART. The project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement no. 680640.

Since new electronic technologies for information and communications and renewable energy are developed at a rapid rate, various materials are significantly used in electronic industry. Among them, rare and precious metals need to be secured for the industry regardless of economic and political situations because they are used as essential materials for the technologies. Also, some metals need to be safely managed in the production, disposal, and recycling stages by preventing their releases to the environment because they are hazardous and toxic to human health and ecosystems. Since newly developed technology affects the contents of metals contained in electronic products, technology development itself can positively or negatively affect potential environmental impacts of products. Thus, this study assesses environmental effects of technology development to figure out whether advanced electronic technology is desirable and what metals are to be managed with priority to prevent environmental impacts. Five case studies are carried out to demonstrate the various environmental effects of technology developments: (i) technology evolution of smart phone; (ii) technology transformations from liquid-crystal display (LCD) to organic light emitting diode (OLED) display, hard-disk drive (HDD) to solid-state drive (SSD), and polycrystalline silicon to amorphous silicon and copper/indium/gallium/di-selenite (CIGS) solar photovoltaics (PVs); and (iii) technology convergence to tablet PC. The resource depletion, hazardous waste, and toxicity potentials of the respective technologies are assessed based on the mass and concentrations of metals contained in the samples of the representative electronic products and environmental impact characterization factors used in life cycle impact assessment methods. The results of this study shows that all the technology developments do not contribute to reducing the environmental impact potentials and that the priority heavy metals are different depending on the technology. Therefore, environmental impacts assessments on advanced technology are required to inform manufacturers to reduce the priority materials and potential environmental impacts of advanced technology-based products in the product design stage and recyclers to safely recover and manage rare, precious, and toxic materials in the end-of-life stage for sustainable circular economy.

Additive manufacturing (AM)—the process of fabricating parts in layer-by-layer fashion—has received much attention as a potentially disruptive technology for reducing the environmental footprint of fabricated metal parts in many end use sectors. Its true potential, however, depends largely on its application feasibility and overcoming major technical and economic barriers, which are difficult to assess using traditional life-cycle assessment (LCA) and techno-economic analysis methods. This presentation will first discuss the importance of life-cycle systems perspectives when assessing the sustainability performance of AM technologies compared to the conventional technologies they replace, starting with a review of recent findings from the LCA literature and a critical comparison thereof. Next, this presentation will discuss how improved modeling approaches are needed, which integrate engineering analysis, life-cycle assessment, energy systems modeling, and economic analysis in dynamic fashion to be used for deeper techno-economic evaluation, thereby enabling more robust AM technology research and deployment decisions. However, many gaps remain in the research community with respect to such dynamic, integrated modeling approaches; these will be highlighted as a call to action for the research community. Furthermore, to illustrate the utility of moving toward more dynamic, integrated sustainability assessment approaches, recent case studies on AM processes applied to lightweight aircraft components and industrial tooling will be presented to highlight knowns and unknowns in the assessment process.

Additive manufacturing (AM) is beginning to enter commercial manufacturing, but its environmental impacts can often be larger than traditional mass manufacturing. Many inventors are developing new "green" materials for 3D printing, but almost none have measured their benefits, and no government agencies have set targets for desired impacts. This study establishes a protocol by which to quantify environmental and functional properties of AM materials, to guide the industry towards developing more sustainable materials and processes.

Previous studies show that AM's environmental impacts are dominated by the energy used during printing, but alternative materials can radically decrease AM energy demand. Instead of necessitating high temperatures to melt thermoplastics, materials that bond or harden chemically at ambient temperature can reduce printing energy use, while also reducing other environmental impacts such as resource depletion, toxicity, and waste. In order to identify viable green alternatives that meet industry performance standards and provide gains in sustainability, this comprehensive protocol combines three environmental metrics into one overall sustainability score and combines three market viability metrics into one overall functionality score. Together, these can be used to aid decision-making, benchmarking, and goal-setting, to drive the industry toward more sustainable production.

Based on the National Academy of Sciences (NAS) method for chemical alternatives assessment, this protocol is customized for relevance to AM. The three environmental metrics are whole-system life cycle assessment (LCA), toxicity, and resource circularity. The LCA integrates seventeen ecological impacts into a unified score using the ReCiPe methodology, and measures not only material production, but the whole printing system, including printing energy, printer embodied impacts, and end of life. Resource circularity is calculated using the Cradle to Cradle Nutrient Reutilization formula. Toxicity is measured using an enhanced version of GreenScreen, using its eighteen hazard categories but providing additional precision and displaying uncertainties (quite common in hazard data). The three functionality metrics are mechanical performance, cost, and expert print quality evaluation. Mechanical performance is measured by a combination of ultimate strength and modulus of elasticity, comparing to ABS plastic's properties. Cost includes only the cost of materials, not saved printing energy costs, because the latter are usually small. Print quality is measured by industry experts handling physical samples and quantitatively rating them on a Likert scale while adding qualitative comments.

Once environmental and functional scores are determined, new alternative materials can be compared to other AM materials, such as ABS and PLA plastics, and can be evaluated on their fitness for a variety of AM applications. This should help inventors of new materials quantify their benefits; it should also help set benchmarks of current best practices and targets for future goals. Together, these metrics and goals can drive the additive manufacturing industry toward a future that is not more damaging, but more sustainable than current production.

Additive manufacturing methods have great potential for rapid production of parts and devices in remote areas with limited access to supply chains. This work examines the use of mineral resources for inexpensive and low-energy additive manufacturing. In particular, earth abundant minerals in conjunction with polymeric binders such as polyethylene glycol (PEG) were used as the material base to print structural components. Silicate, basaltic, and other refractory minerals were chemically functionalized and incorporated in tandem with binders in fused filament fabrication (FFF) or in paste printing. Filaments with powder loading up to 50 vol.% were achieved and used in a commercial FFF printer to fabricate structures, while higher loading was achieved in printing similar structures using commercial paste printers without compromise in structural and mechanical integrity. This work paves way for efficient in situ resource utilization in hostile environments.

Additive manufacturing and 3D printing are synonymous with rapid prototyping and production in limited quantities of or more complex parts and design. Can 3D printing be an important component of a more circular economy? Will it replace traditional high throughput manufacturing? What are the materials challenges for the Six-R concept? Polymers and metals are the materials of primary interest for materials sustainability. An important aspect of 3D printing is distributed production and digital manufacturing that can cross traditional blockchain supply models and distribution. This talk will outline and review important developments and the value chain of 3D printing towards the following: 1) Challenges of adopting the right 3D printing methods and the intricate relationship with the starting material and desired part properties, 2) Savings in time, cost and reduction of waste materials in 3D printing by materials design, 3) Unique applications of 3D printing and replacement of traditional manufacturing modes towards high performance and limited production, and lastly 4) Bio-inspired and design paradigms towards high strength and lightweight materials from aerospace to biomaterials. The talks will also highlight our work employing fused deposition modeling (FDM), selective laser sintering (SLS), and stereolithographic apparatus (SLA) or photopolymerized fabrication of nanocomposite materials. Lastly, the importance of designing polymer materials for the six-R can be emphasized in the early stages of new materials and process development.

The construction is a sector that consumes a significant part in the environmental impact throughout the life cycle. Along with the infrastructure, consume on average half of the materials extracted from the earth's crust. Likewise, it adds millions of tons of CO2 poured into the atmosphere each year, accelerating the greenhouse effect and global warming. With this situation, many efforts begin to be notable, innovations and inventions are made every day in order to reduce the degradation of the environment. One of the most promising paths is the use of sustainable materials in the building, among which clay stands out for its characteristics, such as disposal, reintegration into the environment and low energy cost. The present article presents the results of laboratory tests of clay mixed with an additive of natural components for the most part, which improves the resistance of the clay to compression, as well as the drying time, which allows its hardening without the need of high temperatures. The text also suggests that clay with additive can be used in the construction of building elements such as bricks, in molds or extruder methods.

Currently, the main material for the production of solar cells is still silicon. More than 70% of global production of solar cells is silicon based. For solar-grade silicon production the technologies based on the reduction of silicon from organosilicon compounds are mainly used. These technologies are energy-consuming, highly explosive and unsustainable.

The paper presents the comparison results of a new chlorine-free solar-grade silicon production technology based on purification of metallurgical-grade silicon by vacuum-thermal methods with the existing technologies. The proposed technology provides environmental safety, energy consumption reduction, the process scalability and the cost reduction of obtained silicon.

In this paper, the following studies have been carried out–technical processes of vacuum-thermal and plasma-chemical purification of metallurgical-grade silicon under the conditions of electromagnetic stirring of silicon melt by the mathematical modeling; comparison study of the existing technologies for the production of solar-grade silicon and the investigated technology as far as material consumption, energy intensity of the processes concerned.

The research results are–the results of the study of a new chlorine-free technology for solar-grade silicon production are shown; a comparison study of the existing solar-grade silicon production technologies and the investigated technology is performed; it is shown that the use of the proposed technology reduces the cost, material consumption and energy intensity of the process.

In the past few years, intensive studies on oxide thin film transistors (TFTs) have been reported for their widely use in driving active matrix organic light emitting diodes (OLEDs). Zinc oxide (ZnO) has been the primitive material that is widely used to fabricate TFTs due to its good optical and electrical properties, good uniformity, and low process temperature. Among various ZnO-based TFTs, one of the most promising materials is indium gallium zinc oxide (IGZO), which shows high electron mobility. However, IGZO thin film requires high film deposition and annealing temperature as well. Similarly, indium element is a rare element, and the storage of indium in the form of ore is very limited on earth. The indium-free oxide-based channel materials such as tin doped zinc oxide (TZO) thin film deposited on glass substrate have been optimized using physical deposition technique and their structural, optical and electrical properties have been extensively studied. Sn is a non-toxic, abundant on earth, and is reported to possess excellent electrical and optical characteristics. This work focuses on TZO thin film performances grown by Pulsed Laser deposition on n – type silicon and glass at different temperatures to analyze the effect of growth morphology. The effect of Sn content on microstructures, surface morphology and optoelectronic properties of the films were investigated by X-ray diffraction, Atomic Force Microscopy (AFM), Field Emission-Scanning Electron Microscopy (FE-SEM), Ultra-violet visible spectroscopy, and electrical characteristics. AFM provided thin film roughness, grain size, and surface morphology for both glass and silicon substrates. FE-SEM was used to show the surface morphology with change in deposition time and temperature. The present work will provide valuable scientific input of TZO thin films for the improvement of TFT devices.

Tea produces a large amount of waste during the production process, and the current use of such tea waste does not fully exploit its value. This study reprocessed tea waste to create a new kind of biodegradable material dubbed CHAMU, and, based on the Six-R processes, the concept of a tea-waste recycling system was proposed. In studying this concept, the composition and characteristics of tea waste were analyzed through a literature review. Tea waste is classified into fiber and non-fiber elements, and the different kinds of waste should be processed in different ways. In a molding experiment, the fiber waste was subjected to hot pressing and injection-molding, while the non-fiber waste was subjected to an injection-molding experiment. A universal testing machine (UTM) was used to test the mechanical strength of the CHAMU material, and the biodegradability of the material was examined using the soil-burial test method. These experiments established the practicality of the tea-waste recycling system. The article concludes by describing how the CHAMU material was redesigned to make a series of CHAMU products, and, using the method of design and perceptual analysis, discusses the potential of the high-value-added recycling of tea waste based on this system.

Material and maintenance costs of metal-based heat exchangers surpass profits in waste heat recovery (WHR) from ultra-low temperature (<100C) sources [1]. A low-cost alternative like polymer pipes suffer from poor thermal conductivity (~0.2 W/mK), and a low overall heat transfer coefficient. Polymers’ thermal conductivity have previously been enhanced through systematic molecular alignment by stretching [2], chemical vapor deposition of extended polymers [3], surface grating [4], etc. However, these approaches suffer from scalability issues for WHR heat exchangers in terms of cost [3], and thermomechanical considerations [5]. In this work, we propose novel hybrid metal-polymer heat exchangers that are made from polymer-copper strips. Through finite element method (FEM) simulations, we first optimize the placement of copper around polymer strips to enhance the transverse thermal conductivity of the strips. The copper cladded polymer strips are wound helically in a roll-to-roll system to form the pipes for a heat exchanger. We then optimize the design of helically wound pipes to reduce thermomechanical strains to < 0.2 % at 100C and 40 psi working conditions. At 25 % volume fraction of copper in the pipe, we predict up to 20 % enhancement in overall heat transfer from a base polymer with a thermal conductivity of 0.2 W/mK. We also compare and contrast the thermomechanical performance of the optimized metal-polymer strips to random metal matrix composites. Finally, we experimentally verify the thermal conductivity of the optimized strips through bulk thermal conductivity and thermal interface resistance measurement setup. By systematically improving the design through FEM and experimental measurements, we provide an optimized design of hybrid metal-polymer pipes that provides a low metal footprint and cost-effective means for harvesting waste heat from ultra-low temperature sources.
1. Thekdi, Arvind, and Sachin U. Nimbalkar. Oak Ridge National Lab, 2015
2. Shen, Sheng, et al. Nature nanotechnology 5.4 (2010): 251.
3. Xu, Yanfei, et al. Science advances 4.3 (2018): 3031.
4. Smith, M. K., Singh, V., Kalaitzidou, K., & Cola, B. A. (2015). ACS nano, 9(2), 1080-1088.
5. Aymonier, C., Bortzmeyer, D., Thomann, R., & Mülhaupt, R. (2003). Chemistry of Materials, 15(25), 4874-4878.

Recycling is not an objective in itself, but for the benefits it can bring, including reductions in life-cycle costs, energy use and environmental impacts, and dependence on scarce or imported materials. The options available now for recycling of lithium-ion batteries are not optimal, so research and development (R&D) is needed to make economic processes available for use by the time large volumes of batteries from electric vehicles and other uses go out of service. Even if they find a second use, the batteries will eventually be unusable, and the material will need to be recycled. However, by then the material could be a 20 year-old formulation with little residual value from its structure or contained elements. In particular, cathode formulations are evolving towards varied morphologies, emphasizing formulations that contain reduced quantities of cobalt (the valuable element sought in most current recycling operations), reducing the incentive for recycling with standard pyrometallurgical or hydrometallurgical methods.
Several key questions must be addressed by R&D. Most of these focus on the cathode, which is the most valuable form of material that can be recovered. How can the cathode get separated from the other cell components? Can they be recovered as well? How can optimum cathode function get restored? Can we separate one cathode type from another? Can we modify the cathode composition or morphology to update it for reuse? This presentation will describe new research projects to address these questions.

Niobium is a Group V element with relatively abundance of 20 ppm in the Earth’s crust. Though it is not rare and its natural occurrence is similar to most of the transition metals, niobium enjoys a limited market demand, of around 52,000 tons in 2016. Major producing countries are Brazil, with the world’s largest proven deposits that account of more than 80% market share of niobium products, and Canada [1]. Niobium chemistry is very rich and versatile owing to its multi-valence states (-1 to +5), which implies in very attractive physical and chemical properties. Niobium oxides and related compounds show a large variety of polymorphic structural modifications and metastable phases. These features allow niobium oxides to be extensively used in the preparation of heterogeneous catalysts and of many roles they can play in catalytic formulations are as of active phase, solid acids, promoters, supports and redox components. Several industrial applications are found in selective oxidation, acid-catalyzed reactions, biomass conversion and emission control technologies [2]. More recently, the use of niobium has been extended to energy-related materials by exploring its electronic properties into storage and energy conversion devices such as supercapacitors, fuel cells, lithium-ion batteries and electrochromic materials [3]. The purpose of this contribution is to give an account of the current status of the global niobium industry and its supply of niobium products. It will also highlight the most relevant industrial developments of niobium-containing heterogeneous catalysts and energy-related materials.

[1] Niobium: Global Industry, Markets and Outlook to 2016, Roskill Information Services Ltd., London, UK, 2017
[2] M.O. Guerrero-Pérez and M.A. Bañares, Catalysis Today 142 (2009) 245
[3] L. Yan, X. Rui, G. Chen, W. Xu, G. Zou and H. Luo, Nanoscale 8 (2016) 8443

Critical and strategic materials are characterized by their importance in key applications and their vulnerability to supply chain disruptions. Much current research focuses on identifying and quantifying metrics and indicators that can predict potential supply chain risks for these materials. Sourcing also plays an important role in the environmental impacts of these materials as well. The complexity of both environmental impact and criticality metrics creates challenges to their integration in traditional material selection tools. This work examines the potential for synthesis of these tools in several case study material systems from the clean energy, defense, and electronics industries. This research work uses a functional unit framework borrowed from life-cycle assessment methodologies to quantify metrics for substitution that can better capture functionality trade-offs. It also uses techno-economic analysis to identify material systems where disruptive adoption could cause criticality induced price volatility. Results indicate this approach has several advantages over current qualitative and semi-quantitative indicators and may be better equipped to inform firm-level research and development activities.

Environmental benefits attributed to recycling rely on the assumption that we are substituting energy intensive primary production for lower-impact secondary production. However, this argument tends to be a purely engineering lens on a complex socioeconomic system. Research has begun to test whether closing material and product loops does, in fact, prevent primary production. The basis for this counter argument is that when secondary replaces primary, it decreases the price of secondary and thus more primary will switch to secondary if possible, causing primary price to drop, and driving up demand for more primary which may negate the potential for substitution. There is a strong parallel in this argument to the concept of energy efficiency rebound, and is also referred to as the potential for secondary material to displace primary production. The critical aspects that influence displacement are the ability of secondary products to substitute for primary products, and price effects. This presentation will describe tools and analytical modeling efforts that explore the potential for recycling displacement for the case of commodity materials such as paper, copper and aluminum. These approaches help to assess the contexts under which recycling may reduce a material or product footprint.

Photovoltaics coupled with lithium-ion battery storage are widely heralded as a major part of climate and air pollution solutions, and early evidence from sustainability science support these claims. However, reaching terawatt levels of global photovoltaic electricity generation will require innovations, policies, and practices to encourage sustainable materials use. Some photovoltaic technologies rely on significant portions of the overall demand for several key metals for semiconductors suggesting future supplies will need to be augmented by circular economy concepts. By 2045, the total mass of electronic waste from photovoltaics will pass all other e-waste combined, suggesting this could be a major source of future supplies of key materials. Similarly, some of the metals used to make lithium-ion battery have supply chains that are linked to human rights abuses and environmental contamination in developing countries, with some companies announcing intention to recycle key materials or avoid sourcing them in the future. My talk will highlight the motivations for a circular economy, identify the challenges and opportunities to transition away from linear material flows in photovoltaics and lithium-ion batteries, and describe recent trends in sustainability policy and corporate social responsibility (CSR) in practice in these sectors. Key quantitative key metrics produced by life cycle assessment (LCA) will be presented alongside qualitative evaluations (embodied environmental justice). I will also review emerging standards and frameworks (certifications, supply chain disclosures) used to evaluate, highlight and promote sustainability efforts. My talk will conclude with a critical discussion about the limitations of LCA metrics and CSR information that describe and document the environmental, health, and safety performance of these clean technology manufacturers and their supply chains and suggest how to make LCA, sustainability policy, and CSR efforts generate more actionable information to inform circular economy solutions to enhance the benefits of solar energy coupled with energy storage.

Current lithium ion batteries used on board of electric vehicles have small energy density due to the small specific capacity of electrode materials used. Silicon nanomaterials, with high specific capacity, are widely recognized as promising anode materials for next generation lithium ion batteries. However, current manufacturing processes developed for producing silicon nanomaterials for lithium ion batteries have significant sustainability issues in terms of heavy use of toxic chemicals, generation of nanoparticle emissions, and high energy consumptions. In this presentation, we will report our most recent results on sustainable development of silicon-based nanocomposite materials for next generation lithium ion batteries. Both mathematical modeling and experimental studies have been employed to study the process wastes and emissions from silicon nanomaterial fabrications. Life cycle assessment (LCA) has also been employed to evaluate the cradle-to-grave environmental impacts of two types of lithium ion batteries using silicon nanowire and silicon nanotubes, as anode in the lithium ion battery. The results could be useful for supporting sustainable development and scale-up of silicon nanomaterials for lithium ion battery applications on electric vehicles in future.

The increasing recognition of environmental impacts from the production and usage of conventional energy resources demands that electric grids must achieve high renewable energy adoptions to reduce these impacts. California has established goals to meet, by the year 2050, 100% of the electric demand with carbon-free energy resources and an 80% percent decrease in economy-wide greenhouse gas (GHG) emissions compared to 1990 levels. Meeting these goals will require the deployment of energy storage systems to manage variable renewable resources such as wind and solar. Flow batteries have the advantage of scalability to high capacities, the separation of energy and power modules, long cycle life, and fast response times. While significant research has focused on improving flow battery performance and efficiency, few studies have explored their potential environmental impacts. In this study, we perform a materials life cycle analysis to evaluate the environmental impacts of three battery chemistries. The environmental impacts associated with the raw materials extraction, product manufacturing, and product assembly are evaluated and compared using SimaPro and Ecoinvent, with an emphasis on global warming potential (GWP), ozone depletion potential (ODP), particulate matter (PM), acidification (AP), eutrophication (EP), abiotic resource depletion (ADP), cumulative energy demand (CED), and ecotoxicity (ETP). Impacts associated with the use-phase of flow batteries were evaluated through the application of the energy systems modeling tool HiGRID. The results provide insight into the effects of product design and material selection choices on the potential environmental footprint of these novel energy storage devices.

Life cycle assessments (LCAs) are a standard method to perform accurate and thorough environmental assessments on a variety of products and processes. These assessments can be used to generate data about the environmental impact of a product throughout its life cycle, and can be performed to inform decisionmakers, support policy, and guide design. Ideally for product design, LCAs will be performed at every stage throughout the development process. Practically, system and informational limitations create trade-offs between design freedom and assessment reliability: the earlier an assessment is performed the less comprehensive it can be, but the later an assessment is performed the less the design can be changed. Considering this trade-off, this work outlines a life cycle assessment that has been completed on a Cu₃AsS₄ semiconductor that is a strong alternative solar absorber candidate – if it can be developed sustainably.

Cu₃AsS₄ has recently gained attention as a solar absorber material after Yu et al.¹ calculated its high absorption properties and high spectroscopic-limited maximum efficiency. Density functional theory (DFT) calculations suggest this material may be tolerant to deep defects,² and it has been experimentally determined to have an ideal direct band gap and exhibit strong photocurrent characteristics on a natural mineral sample.³ Only recently has this material been synthesized into a thin film solar cell architecture and demonstrated a non-zero photoconversion efficiency.⁴ In conjunction with improving its efficiency, the objective throughout development is its sustainable design, which is particularly relevant for the development of Cu₃AsS₄ because of the inherent risk of developing a technology that contains arsenic. Although sustainable development must consider more than only an environmental perspective, this work serves to establish the basis of the environmental implications of this potential technology.

We present a cradle-to-cradle life cycle assessment of this material and compare its potential impacts to other renewable and non-renewable energy technologies. Scenario and sensitivity analyses are completed to understand the degree of impact that design parameters have on the environmental performance. This information will lead to a discussion on considerations for the sustainable design of Cu₃AsS₄ solar technology.

1. L. Yu, R.S. Kokenyesi, D.A. Keszler, and A. Zunger, Adv. Energy Mater. 3, 43-48 (2013).
2. S.K. Wallace, K.L. Svane, W.P. Huhn, T. Zhu, D.B. Mitzi, V. Blum, and A. Walsh, Sustainable Energy Fuels 1, 1339-1350 (2017).
3. T. Pauporte and D. Lincot, Adv. Mater. Opt. Electron. 5, 289-298 (1995)
4. S.A. McClary, J. Andler, C.A. Handwerker, and R. Agrawal, J. Mater. Chem. C 5, 6913-6916 (2017)

As materials scientists, researchers and engineers, we are responsible for the substances that go into our products, as well as those in our synthesis and manufacturing processes. Many of these substances kill and cause disease, others gobble energy when refined and used, still others are in limited supply yet we casually throw them away. We need to do better - much better. This five-person panel discussion will allow the ES13 Symposium Organizers to share provocative insight into both the challenges and solutions associated with making materials experts better guardians of our world.

Panelists:
Carol Handwerker
Bill Olson
Alan Rae
Julie Schoenung
Ashley White

Metals recovery from electronic product recycling is currently focused on high-volume metals that are easily recoverable and on low-volume, high-value precious metals. Current and future electronics will increasingly contain small quantities of materials which are not currently recovered in today’s recycling infrastructure. Trends toward miniaturization, product dematerialization, and increasing materials heterogeneity create increasing challenges with respect to materials recovery, and the financial viability of electronics recycling generally.
In particular, the project examined whether conditions exist in the electronics and recycling industries to develop a voluntary, community-based solution involving adaptive governance systems to self-manage used electronics as common pool resources. This concept was inspired by the work of Dr. Eleanor Ostrom (2009 Nobel Laureate in Economics). It was concluded that the necessary conditions do exist, and that the time was right to take the next steps.
Therefore, iNEMI (the International Electronics Manufacturing Initiative) undertook a collaborative project to examine the role its members could play in increasing materials recovery, while promoting sustainable electronics. The main take-home message from the project was that the situation is bad and getting worse if we consider materials recovery as the only option for end-of-use (EoU) electronics. As a result of that project, a new iNEMI project was then launched to focus on value recovery from hard disk drives (HDDs), including multiple existing and possible future dimensions of an EoU system that could improve its effectiveness, financial viability, and sustainability. The dimensions examined ranged from reuse and remanufacturing of HDDS to reuse of components, transformation of components for use in other applications, and recycling of critical materials as well as commodity materials being lost under the existing recycling paradigm.
The project aims to study and implement a proof of concept of the necessary conditions and issues involved to develop a voluntary, community-based solution involving adaptive governance systems to self-manage common pool resources. Though the focus is on the reuse and recovery of spinning media (Hard Disk Drives) and rare earth magnets, the principles can be applied to any used electronic product.
It includes,
Identifying Criteria for Enabling Reuse of used, functioning HDDs and of components from used, non-functioning HDDs
Identifying Criteria for Enabling Reuse of HDD components in HDD applications – both direct and indirect for metal components, disks, magnetics, motors, head, PWBs etc.
Identifying Criteria for Enabling Reuse of magnets in non-HDD applications
Developing economic and logistics estimates for cases studies
Establishing necessary Design principles for the system for value recovery
Conducting a Demonstration project on HDD recovery to validate the principles identified
Benchmarking the current reuse and recovery (direct, indirect) and barriers with stakeholder input
Identifying the Leverage Points, mapping the supply chain, and identifying key gaps for developing a circular economy including each value recovery pathway for HDDs

A review of existing recyclability and reusability metrics revealed that the industry has limited means of practically assessing circular economic value (recyclability, reusability, reparability and refurbish-ability) of an ICT product. Current mass-based metrics, in their most simplistic form, are deficient. Product designers control material and design choices which affect downstream end-of-life costs, while the market controls the materials that are recovered. Yet, no metric or guidance links these attributes together.
The iNEMI Reuse and Recycling Metrics Project team has been developing a practical means for assessing the circular economic value of an Information and Communication Technology (ICT) product with the focus on incorporating score factors that assign reasonable impact value to product design features along with the ability to recover (whole products, parts) and return value (from reuse, recycling and/or energy recovery) back to the market. Included in this scoring factor are highlighted aspects that are within the product designer’s control such as material choice and ease of liberation of components and materials and those aspects outside the product designer’s control such as the availability of recovery for reuse/recycling technologies in the markets where the product is placed. The metric assigns a reasonable impact value based on the design and a weighted recovery rate, which brings the actual results into the traditional mass-based metrics. The project is developing an assessment tool for the ability to disassemble a product for repair and recovery of whole product, components and parts.
The resulting system assesses the economic feasibility and physical practicality to separate and liberate the parts, components and materials from ICT type products when whole product reuse is not possible. The assessment is divided into three tiers; material choice, ease of liberation, and the available recycling technology. Regional factors have also been researched and incorporated in the assessment criteria. Additionally, the team reviewed the hierarchy of recovery, which impacts the ease of returning value to the market: repair and reuse, parts harvesting, material recovery, or energy recovery/landfill.
ICT stakeholders, including product designers, manufacturers, customers, recyclers, governmental authorities, and environmental advocates can use this means to assess the relative impact of product design choices early in the product life cycle. This will benefit both the industry and the environment to achieve sustainability. The intention for the metric is to identify gaps that prevent return to market value by highlighting the most impactful action(s) needed to close the gaps, and to inform product designers and manufacturers of the end-of-life impacts of their decisions.

The recycling of waste electrical and electronic equipment (WEEE) has been a great challenge for the recycling industry in the last decades. Predictions on the future volume of such waste shows that it will rapidly increase during the coming years (Baldé et al., 2015). Some of the waste fractions derived from WEEE are considered to be hazardous, since they contain toxic compounds restricted by the Directive of EU (2002) for Hazardous substances in WEEE. Therefore, the scientific community are focusing on finding alternative processes in order to minimise their environmental impacts and eliminate the risk of human exposure during recycling.
Previous studies have investigated several processes for recycling of WEEE in terms of materials or energy. Pyrolysis is one of the alternatives which combines both energy and partially materials recovery through its production of oil and gas. Moreover, the solid residue, which contains high percentage of metals in non-oxidised form can be recovered through hydrometallurgical process.
The current study investigates the decomposition of three representative WEEE fractions, collected at a recycling plant located in Sweden focusing on feedstock recycling. The experiments are performed in a thermogravimetric analyser (TGA) in order to evaluate their decomposition behaviour. Furthermore, pyrolysis experiments have been performed at different temperatures (300-700 oC) in order to correlate the pyrolysis products with the choice of temperature. Through these experiments a kinetic study has been performed aiming to design a process that can maximize the production of specific organic compounds while minimizing the evolution of brominated compounds, which are usually present in the oil (Evangelopoulos 2015).
Tests were also performed in a semi industrial continuous pilot plant designed to treat 1kg of WEEE per hour. The experiments examine the possibility of releasing less brominated compounds according to the different tested temperature conditions. Moreover, the properties of the oils obtained by the process was also investigated experimentally in order to conclude to the application of this as a new material for feedstock recycling or for energy purposes. Finally, the results shows a route that should be followed for implementing pyrolysis in order to minimize the material and energy loses in the concept of circular economy towards a more sustainable way of recycling the WEEE.

In light of growing demand and pollution versus a finite amount of resources, electronic waste recycling is a way towards material circularity. Due to the complex composition of end of life products and the physical characteristics of the materials, it becomes more difficult to recover pure metals form the waste stream. Especially rare metals, which, although abundant in the earth’s crust, only occur in low concentrations, are a sought after commodity as they are important for the economy and are found in numerous products. New recycling technologies not only face technical difficulties but also need to overcome challenges of feasibility in both economic and environmental aspects. An assessment regarding environmental impacts and economic factors at the early development stages of such technologies is necessary to ensure a successful establishment.
Bioleaching has been specifically applied in copper recovery since the 16^th century and is now also used to win metals such as zinc, gold or cobalt. Using this hydrometallurgical approach for the recovery of by-metals such as indium is an innovative approach in the first development stages. Indium-rich material such as electronic waste is leached in a bioreactor as opposed to the environmentally risky heap leaching. The beneficiation process of indium from electronic waste can be classified into four steps. In a first step, the material is crushed and comminuted. The fines are then fed into a bioreactor, where bioleaching takes place in multiple stages. The third and fourth steps are the solvent extraction and subsequent recovery of the target metal from the solution. In a combined process, indium rich tailings and primary ores could also be added in the reactor to ensure a stable input and independence of the amount of end-of-life products.
The novel existent technology of using bioleaching as a hydrometallurgical process to win indium from electronic waste will be assessed exemplarily. This presentation will focus on preliminary results of batch trials in a lab scale bioreactor, whereby Indium was recovered from the electronic waste recycling process. Hereby Life Cycle Assessment is used to determine the ecological factors. Further, the environmental risks connected to this technology are summarized and put into perspective. LCA offers a standardized opportunity to determine the environmental impacts over the life cycle of a given product but can be applied to processes. The data is used to establish the feasibility of this recycling technology including both economic and ecologic parameters.

In the push for a more sustainable economy, fiber reinforced polymer composites (FRPCs) have proved an important component in implementing this vision. FRPCs have improved energy efficiencies in the transportation sector through the lightweighting of vehicles, such as aircraft and cars, and have enabled alternative energy technologies such as wind. The increasing use of FRPCs, however, has led to a corresponding increase in composite waste, such as production scrap from carbon fiber composite aircraft and accumulating end of life wind turbine blades. Up until the last half decade or so, no successful techniques for recycling these materials existed resulting in near 100% of all FRPCs being destined for landfill. Recent successes repurposing waste-to-energy pyrolysis technology, already developed for the processing of feedstocks like e-waste, have resulted in the emergence of a nascent recycled carbon fiber (rCF) industry. In these pyrolysis systems, polymer matrix materials are converted to energy while the reinforcing fiber is reclaimed for 2^nd generation (and beyond) composite production.
In this talk, research efforts to extend the success of rCF to the recycling of glass fiber reinforced composites (GFRCs) will be discussed. GFRCs comprise over 90% of all FRPC production; however, they also exhibit numerous technical challenges that have limited progress in their recovery. Emphasis will be placed on addressing glass fiber embrittlement incurred during pyrolysis processing and re-engineering fiber surface chemistry for redispersion in new polymer resins. Optimized recovery and postprocessing are essential for producing recycled glass fiber (rGF) of sufficient value that can economically support a rGF industry and begin closing the loop on FRPC materials writ large. Discussion will also include details from initial pilot plant scale pyrolysis trials completed in partnership with the Institute for Advanced Composites Manufacturing Innovation (IACMI) and the American Composites Manufacturers Association (ACMA).