1 Sustainable Materials Management Metrics to Assess Consumer Technology Summary Report of Phase 3 Research: Development and application of sustainability metrics to identify environmental, economic, and social issues and opportunities for materials used in technology products January 2019 Authors: Shahana Althaf Callie W. Babbitt* Hema Madaka Gabrielle Gaustad Carli Flynn *Corresponding Author [email protected]Golisano Institute for Sustainability Rochester Institute of Technology
Transcript
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Sustainable Materials Management Metrics to Assess Consumer Technology Summary Report of Phase 3 Research: Development and application of sustainability metrics to identify environmental, economic, and social issues and opportunities for materials used in technology products January 2019 Authors: Shahana Althaf Callie W. Babbitt* Hema Madaka Gabrielle Gaustad Carli Flynn *Corresponding Author [email protected] Golisano Institute for Sustainability Rochester Institute of Technology
Table of Contents Importance of materials in consumer technology ................................................................. 3 Importance of metrics for assessing materials in consumer technology ............................ 4 Research approach .................................................................................................................. 5 SMM metric development ........................................................................................................ 6 Results ...................................................................................................................................... 7
Measuring physical availability of materials ............................................................................ 9 Measuring competing demand for CT materials ....................................................................11 Measuring geographical concentration of material production ...............................................13 Measuring environmental risks of material production ...........................................................16 Measuring economic risks of material production ..................................................................19 Measuring social risks of material production ........................................................................23 Measuring sustainability issues for EOL material management .............................................25
Using SMM metrics to identify potential sustainability solutions .......................................27 Material case studies ..............................................................................................................31
Key issues for battery materials .............................................................................................31 Key issues for rare earth elements ........................................................................................34 Key issues for plastics ...........................................................................................................36 Key issues for quantum dot technology .................................................................................39
Conclusions ............................................................................................................................43 References ..............................................................................................................................44 Appendix: Additional Data and Tables ..................................................................................47
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Abstract In a collaboration between Rochester Institute of Technology, Staples Sustainable Innovation Lab, and the Consumer Technology Association, research was carried out to create a comprehensive set of “sustainable materials management” (SMM) metrics that can be used to proactively assess anticipated material demand and material-specific sustainability risks and opportunities associated with future adoption of consumer technology products. These metrics were tested by applying them to current and emerging consumer technology products. Results helped identify sustainability issues and opportunities for eliminating or minimizing materials with potential environmental or human health risk, closing the loop on materials that are scarce or have low recycling rates, or improving sourcing options by increasing the viability of secondary material markets. Importance of materials in consumer technology The consumer technology (CT) industry has grown rapidly in the U.S., reflecting a high rate of technological innovations and increased consumer adoption. In parallel, the CT landscape has shifted drastically in recent years, with the advent of ‘Internet of Things’ and connected, “smart” technologies and continued trend towards lightweight mobile products. While technological progress and wider adoption have led to greater functionality and benefit to consumers, they may also present new challenges for economic, environmental, and social sustainability. Materials are a key facet of this sustainability challenge: they provide the optical, electrical, thermal, chemical, and physical properties that equip CT products with the form, finish, and functionality that consumers demand, and as a result, the demand for an increasingly diverse set of materials has been observed over time (Figure 1).
Figure 1: Elements used in semi-conductor technology over time (T. McManus, Intel Corp, 2006, adapted by Graedel and Allenby 2010).
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Material systems also play a critical role in sustainability across the life cycle of consumer technology (Figure 2). Their mining, extraction, refining, and preparation for integration into CT products and components are key inputs to the CT life cycle, and ultimate recovery of materials at end of life is the potential bridge to more closed-loop product systems. Materials themselves may not play a significant role in all environmental challenges facing consumer technology. For example, material production is estimated to contribute less than 10% to the life cycle greenhouse gas and embodied energy of a typical laptop or desktop computer (Deng et al. 2011), compared to consumer use and manufacturing processes, particularly semiconductor fabrication, which have a much larger contribution to the total product impact. However, materials play an important enabling role in those systems, potentially imbuing components with properties that directly or indirectly impact their use-phase energy consumption. Increasing demand for diverse CT materials has also created new environmental, economic, and social considerations. These materials are widely used in the global economy, and demand from the CT sector compounds the growing demand for scarce or critical materials that are also required by clean energy technologies like solar panels and wind turbines. Many CT materials are currently sourced from only a few countries, leading to potential business risks if supply chains are disrupted by political instability. Extraction processes may require significant amounts of energy and water and lead to a wide array of chemical emissions. Many of these impacts can be reduced through use of secondary (recycled) sources, but barriers exist in lack of recycling infrastructure and secondary material markets. To ensure sustainable growth in the technology industry, it is necessary to fully evaluate and make informed decisions about the choice of materials used in products, their quantity, where they are sourced from and how they can be recovered at end of life. Importance of metrics for assessing materials in consumer technology Sound sustainable material management (SMM) decisions require comprehensive information about potential sustainability issues associated with the extraction and use of the varied materials required for consumer technology – now and projected in the future. Such information could be used to identify material “hotspots” or to prioritize environmental and economic innovations that achieve sustainability solutions. Unfortunately, there is a significant gap in such comprehensive knowledge on material sustainability issues specifically for CT products. Existing data are fragmented among different organizations or yet to be collected because some sustainability issues are not yet perceived to be important for CT sustainability decision making.
Figure 2: Consumer technology product life cycle
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These gaps underscore the need for research on SMM metrics that can quantify sustainability issues of importance for the CT industry. Therefore, this project was carried out with the primary goal of developing a comprehensive knowledge base about sustainability dimensions of CT materials. The research was carried out through research in five integrated stages:
1. Identifying materials commonly used or expected to be used in electronics based on material profile data, carried out in previous research phases;
2. Developing metrics to express potential sustainability challenges across the material life cycle system;
3. Collecting data on the proposed SMM metrics through literature review and analytical data analysis;
4. Identifying material “hotspots” and opportunities for improving the sustainability profile of key materials; and
5. Highlighting insight on select material case studies that represent the wide array of sustainability issues considered.
Research approach The methods applied to implement the stages listed above were carried out through direct data collection, literature review, and analysis using life cycle software. The materials of study were determined based on product material composition characterization performed as part of past CTA-SSIL-RIT collaborative research (Phase 1 and 2) and summarized in Table 1.
Base metals Critical metals REEs Polymers Emerging materials Al Sb La ABS Quantum dots Cu Ba Ce HIPS Carbon fiber Mg Co Pr PA Carbon nanotubes Fe Ga Nd PPE Microfibers Ni Gr Sm PS Bioplastics Zn In Eu PPO Other Materials Ti Li Gd PC Glass Precious metals Mn Y PMMA Epoxy (PCB) Au Ta Tb Rubber Silicon Ag Te Dy Silicone Semiconductors Pd Sn Ho PVC Flame retardants Pt V Er Rh Hazardous metals Tm Ru Pb Yb Ir Hg Lu Os Cr Cd
Table 1: Consumer Technology Materials (CT Materials) To the extent possible, data were compiled from product disassembly in the lab and published literature on material concentration in consumer technologies. Data from the disassembly of over 75 different products were used to characterize the mass contribution of complex components such as display units, batteries and printed circuits boards, and bulk materials like
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steel, aluminum, and plastics in different product categories. Material composition of complex components were characterized by detailed analysis of published literature on electronics material footprint (e.g., the breakdown of precious metals in printed circuit boards). The CT materials are grouped into base metals, precious metals, critical metals, rare earth elements, hazardous materials and plastics. The study also explored a few materials such as quantum dots and carbon fibers, which are key components of some emerging consumer technologies expected to enter mainstream market. Unfortunately, not all materials are represented equally in the available data sources and literature. In these cases, some materials ultimately had to be omitted or analyzed on a more limited basis within select case studies. SMM metric development The broad spectrum of materials identified as relevant to consumer technologies (Table 1), signifies the need for comparable breadth in assessing sustainability. The first goal in metrics development was to capture sustainability issues that span the entire material life cycle. This process also sought to understand sustainability priorities shared by CT stakeholders as being relevant to their materials management goals and decisions. As such, proposed metrics and preliminary results were presented to stakeholders at multiple points in the research project, and any feedback shared was incorporated to the analysis were possible. The metrics also reflected priority issue areas formulated by CTA: resource consumption, environmental and health impacts, and risks to business continuity. These inputs, as well as literature review on sustainability metrics, were used to develop the proposed metrics described in Table 2.
Table 2: Proposed SMM metrics for CT materials The potential sustainability issues surrounding CT materials were considered with possible ways to measure them quantitatively, followed by review of published academic literature and industry reports, to identify metrics commonly used to evaluate each of the environmental, economic and business continuity risks associated with the sourcing and use of materials.
Mineral reserve, Ore concentration Annual Mine Production
Geographical concentration of production Electronics Sector Consumption
Depletion rate
Extracting and refining materials
Environmental impacts of
production Economic Impacts
Social Impacts
Carbon Footprint, Mineral Resource Demand,
Energy Demand, Water Footprint
Price (and price volatility) Socio-Political Stability of Producer
Countries
End-of-life material
management
How much is available to recycle? How much is recycled?
What are the potential issues in recycling?
Market for recycled material Dilution of material in waste,
Potential for material circularity Performance of recycling processes
Toxicity of materials if released
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Results The sections below present the results and interpretation of key sustainability metrics across the life cycle of CT materials. Definition of metrics and additional details used in their measurement are also included. Part 1: Material Availability and Demand Sustainability in obtaining a material depends on its physical availability within the earth’s crust. Availability can be quantified by establishing amount present in mineral ore deposits, the quality or concentration of the material in its ore, how much of the material is produced annually from its ore, and where it is produced. Metrics used to assess physical availability of a material are: global reserves of a material, ore concentration, annual mine production of the material, its depletion rate based on current consumption rate and the geographical concentration of its production expressed as Herfindahl-Hirschman index (HHI Index), a commonly accepted statistical measure of market concentration. The reserve of a material is the working inventory of economically extractable mineral ore, or in other words, the part of an identified resource or mineral deposit that can be legally and economically extracted using currently available technology (Figure 3). Ores are extracted by mining and then refined to extract the metals or elements. The ore grade, or concentration of an ore mineral is the quantity of mineral present in a rock or its parent metal and it directly affects the costs and environmental impacts associated with those extraction processes.
Figure 3: The distinction between reserves and the resource base, from Ashby et al. (2012) The depletion rate of a material provides a timeline for how long a material will be available, given current uses, where a lower index of depletion indicates a more vulnerable material. Depletion rate is calculated as a ratio of global reserve of a material to current consumption rate (annual mine production). Note that ‘reserve’ of a mineral is very different from its ‘resource’ base, which includes both known and unknown deposits of a mineral, even if not currently available (see Figure 3). Therefore, depletion rate of 100 years does not mean that the material will be available ‘only for’ 100 years, but that it is ‘guaranteed to be available’ for 100 years at the current rate of consumption.
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The amount of material consumed by the electronics industry is also important in measuring potential supply risks. Electronics sector demand is measured as the percent of annual mine production of a material, relative to all other uses. These data are adapted from the U.S. Geological Survey annual Mineral Commodity Survey and Gradeal et al. (2013), and it should be noted that this data source includes all types of electronics in this category, including both consumer products and electronic appliances. Results on these metrics are presented in Table 3 as a heat map, wherein the darkest blue represents the greatest risk, and the lightest blue presents as a light blue. Gray indicates that no reliable data were available or included. This representation is used throughout the results sections (absolute results in Appendix Table A1.)
Materials Global Reserves (metric tons)
Ore concentration
(%)
Annual Mine Production
(metric tons)
Rate of depletion based on
reserve (years)
Base
M
etal
s
Al Cu Mg Fe Ni Zn Ti
Prec
ious
M
etal
s Au Ag
PGM
Crit
ical
M
etal
s
Sb Ba Co Ga Gr In Li
Mn Ta Te Sn V
REEs
Haz
ardo
us
Met
als
Pb Hg Cr Cd
Table 3: Measuring physical availability of common CT materials using metrics: global reserves, ore concentration, annual mine production and rate of depletion. REES: Rare earth elements; PGMs: Platinum group metals. Annual mine production is for year 2017. Data sources: USGS; Henckens et al (2016), Sverdrup et al (2017), Goe & Gaustad (2014).
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The physical availability or scarcity of materials, in terms of availability, consumption and depletion, shows that it is not a potential issue for base metals like iron, aluminum, and copper, when compared with precious and critical metals. Precious metals and critical metals like indium, gallium, and tantalum are identified as materials of concern in terms of global reserve and ore concentration. Depletion rate again highlights indium, which is a key material in flat panel display technologies, as a potential material of concern. Precious metals like gold and silver, and some of the critical metals like tin and antimony also emerged to be materials that pose scarcity risk due to depletion rate. Low or moderate depletion rate only indicates that there is no immediate risk to supply if the consumption rate remains constant in near future. Risk to material availability also depends on demand by other industries, to some extent. For example, in the case of gold which is a material of concern in terms of physical availability, the major use sector is jewelry, the consumption in which is expected to remain constant and therefore its depletion rate is not expected to worsen. However, in the case of lithium and cobalt, these materials have high demand in CT industry because they are a critical input to lithium ion batteries used in mobile devices. Their consumption is also expected to grow in parallel with the electric vehicle industry expansion, which will likely increase the estimated depletion rate. These findings highlight the opportunity to explore sustainability solutions, such as finding functionally equivalent substitutes with lower impacts, or increasing recycling rates. A similar case is seen for REEs, as their demand is expected to grow in clean energy applications. The relative use of each material in the electronics sector and in other applications is shown in greater degree in Figure 4. It is to be noted that electronics sector consumption indicates both electronics and electrical applications and is therefore considered as a maximum use scenario.
Measuring physical availability of materials
Key Findings:
• Precious metals and critical metals like indium, gallium, antimony, tantalum and tin identified as materials of concern due to low reserve availability and increased consumptions.
• Battery materials like cobalt and lithium have moderate risk, which may grow with increased demand from automotive sector.
• Physical availability was not a major concern for base metals like aluminum and copper.
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Figure 4, left: Comparing material demand in CT (electrical & electronics) relative to other sectors. Table 4, above: Major use sector for each CT material.
Material Demand in Electronics SectorMaterial Demand in Other Sectors
Base
M
etal
s Pr
ecio
us
Met
als
Crit
ical
M
etal
s R
EEs
Haz
ardo
us
Met
als
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Another factor that affects material availability is the extent to which the reserve base and mine production are geographically concentrated within one or a few countries. High concentration introduces supply chain risk due to excessive control that the producing countries exert on material production. In the event of political instability, policy barriers, or natural disaster, the supply chain is more vulnerable to disruptions that may increase material price or decrease availability to the CT sector. Figure 5 presents the geographical concentration of material production expressed as the Herfindahl-Hirschman index (HHI Index), a commonly accepted statistical measure of market concentration, along with the geographical distribution of production (major countries where the materials are primarily mined). Figure 5 shows that concentration of production (HHI) is relatively high for many common CT materials, indicating that only a few materials have a geographically well distributed production. REEs, mercury, tellurium, graphite, platinum, antimony and magnesium are identified to be materials of highest concern in production concentration. The production contribution of major producers for CT materials shows that more than 50% of each of the material is produced in less than two countries, with China being the primary producer in most cases.
Measuring competing demand for CT materials
Key Findings:
• Demand by the electronics sector is highest for REEs, especially Neodymium (Magnets), Dysprosium (Magnets), Samarium (Battery Alloys) and Europium (Phosphors).
• Critical metals such as gallium (IC chips), indium (flat panel displays), cobalt (batteries) and lithium (batteries) are also consumed heavily in the electronics sector.
• Consumption driven by electronics is insignificant for base metals as well as precious metals.
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Figure 5: Geographical concentration (HHI) (left – heat map) and geographical distributions of mine production (right – bar chart) of common CT materials, showing top four producing countries in 2017. Data source: USGS, Mineral Commodity Summaries.
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However, it should be noted that whether geographical concentration of production actually poses a high risk to sustainability in the CT industry depends on additional factors. For example, a parallel consideration should factor in the socio-political conditions and the environmental impacts of material mining and refining in the major producing countries. These issues will be examined further in the next section.
Measuring geographical concentration of material production
Key Findings:
• REEs, mercury, tellurium, graphite, platinum, antimony and magnesium have highest geographic concentration, potentially introducing supply chain vulnerabilities.
• More than 60% of CT materials are high or moderate risk based on geographical concentration of production.
• For more than 65% of CT materials, the major producer is China.
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Part 2: Environmental, Economic, and Social Impacts of Material Supply Chains The sustainability considerations associated with material supply chains include environmental, social, and economic factors. Environmental issues include carbon emissions, water consumption, energy use, and mineral resource consumption associated with the extraction and refining of a material. Social issues typically depend on the socio-political stability of the country in which a material is mined and processed. Economic dimensions include price of a material and price fluctuations due to variable industry demand and other market factors. Metrics used to characterize sustainability of CT material supply chains are defined in Table 5.
Environmental Metrics Definitions Units
Carbon footprint Supply chain carbon emissions from processes required to
extract and produce a material kgCO2-eq
Energy demand Net energy and fuel resources associated with extracting and producing a material MJ
Water footprint Direct water consumption for extracting processing a material) and water stress index of producer countries m3
Mineral resource demand Cumulative input of mineral resources associated with extracting and producing a material kg Fe-eq
Economic Metrics Price Price of unit mass of raw material in year 2017 $/pound
Price volatility Price fluctuations over time % Social metrics
Geographical concentration weighted for political instability Conflict Minerals --
Table 5: Metrics used to measure sustainability issues in extracting and refining materials. Environmental issues in material production: Environmental issues for material supply chains are presented as a heat map in Table 6. For results in absolute numbers please refer Appendix Table A3. The heat map highlights materials with potentially high resource demand and environmental impact due to extraction and refining stages. Precious metals are clearly the materials of highest concern when considering metrics per unit mass of material produced. Rare earth elements also have significant impact on the environment, while most base metals, which are used in large quantities in CT products have lower impact to the environment.
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Materials Carbon Footprint Energy Demand Water Footprint Mineral Resource
Demand
Base
M
etal
s
Al Cu Mg Fe Ni Zn Ti
Prec
ious
M
etal
s
Au Ag Pd Pt Rh
Crit
ical
M
etal
s
Sb Ba Co Ga Gr In Li Mn Ta Te Sn V
REE
s
La Ce Pr Nd Sm Eu Gd Y Tb Dy Ho Tm Yb Lu
(Continued on next page)
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Haz
ardo
us
Met
als
Pb Hg Cr Cd
Table 6: Environmental sustainability in production of common CT materials. The heat map is color coded as ‘dark blue- higher risk, light blue-lower risk’ to enable identification of hotspots. Gray indicates ‘No Data’. Data source: ecoinvent database in Simapro LCA software. Platinum group metals such as Ir, Ru and Os are not included in the table due to data unavailability.
Note that the results in this section represent impact per unit mass (kg) of material produced. However, high impact materials like precious metals and REEs are actually used in CT products in a very low concentration. Ultimately, the overall environmental risks are associated with the how the material is used in a product or the electronics sector more broadly. Figures 6a and 6b demonstrate how the relative contribution of materials to environmental impacts varies at different levels: per kg of material produced, per product (using the smartphone as an example), and at an industry sector level.
Materials Carbon Footprint Energy Demand Water Footprint Mineral Resource
Demand
Measuring environmental risks of material production
Key Findings:
• Precious metals have higher impacts from extraction and refining, primarily because their ore grade is low and thus, significant energy and water resources are required for their recovery.
• Among materials whose demand is mainly driven by the CT sector, lithium, cobalt, gallium and a few REEs pose higher environmental risks from their production.
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Figure 6a: Relative contribution of materials to carbon footprint at different levels: per kg, per product and at industry sector level
Figure 6b: Relative contribution of materials to water footprint at different levels: per kg, per product and at industry sector level
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While precious metals have the highest environmental risk for some metrics (in terms of both the carbon and water footprint) when considering their production as a standalone process (per kg of material produced), their contribution declines slightly at the product level (relative to materials comprising a typical smartphone). However, at the level of the electronics sector, base metals like steel and aluminum, contribute more to net environmental risks due to their high volume of consumption. Again, it must be noted that the data sources from which information was obtained to characterize industry consumption actually include a broader set of products within this sector (consumer technology as well as appliances and commercial electronics). These results underscore the importance of context when considering sustainability issues and developing potential solutions (which will be discussed in a following section). Economic issues in materials production: The most straightforward metric to consider regarding economics is material price, which reflects inputs required to obtain a material and demand for its use in an application. However, it is also interesting to consider price fluctuations over time, which can introduce uncertainty and vulnerability to the CT sector. Results below demonstrate the concept of “price volatility’ for key CT materials, using the last five years of price data.
Figure 7a Figure 7b
0
2
4
6
8
2013 2014 2015 2016 2017
$ pe
r pou
nd
Base Metals
Al Cu Mg Fe
Ni Zn Ti
0
5,000
10,000
15,000
20,000
25,000
2013 2014 2015 2016 2017
$ pe
r pou
nd
Precious Metals
Au Ag Pd Pt
Rh Ru Ir
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Figure 7c Figure 7d Price volatility for materials between 2013 to 2017. Price is expressed as dollars per pound.
Price fluctuations are shaped not only by supply and demand of materials but are also influenced by geopolitical instabilities. For example, with the recent implementation of tariffs by the U.S. on imported steel (25%) and aluminum (10%), concern has been raised about price volatility and potential for negative economic consequences to manufacturing, wholesale trade, and construction industries. While sufficient evidence has not yet been reported about the negative consequences of the tariffs, short term price volatility of steel and aluminum does show a dip from pre-tariff levels (Figure 8a and 8b).
3
5
7
9
11
13
15
0
50
100
150
200
250
300
350
2013 2014 2015 2016 2017$p
er p
ound
of S
b, L
i , S
n)
$ pe
r pou
nd o
f Co,
Ga,
In,T
aCritical Metals
Co Ga InTa Sb LiSn
0
1
2
2
3
0
75
150
225
300
375
450
2013 2014 2015 2016 2017
$ pe
r pou
nd o
f Ce,
La
$ pe
r pou
nd o
f Nd,
Eu,
Tb,
Dy
REEsLa Nd EuTb Dy Ce
Measuring economic risks of material production
Key Findings:
• Absolute price is higher for precious metals, but price volatility is greater for critical metals and REEs
• Economic risk to the CT sector also depends on material demand and criticality for a given application, which may be higher for metals like indium, gallium, cobalt and lithium.
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Figure 8a: Annual and monthly price fluctuations in heavy melting steel scrap.
Figure 8b: Long term and short-term price fluctuations in aluminum. Social issues in material production: The sustainability risks to material production due to socio-political factors is measured by extending the previously presented assessment of geographical production concentration to factor in potential for political instability in the producing countries (estimated by weighting the HHI using the World Governance Indicator of socio-political stability).
0.06
0.08
0.1
0.12
0.14
0.16
0.18
2013 2014 2015 2016 2017 2018
HM
S pr
ice
per p
ound
($)
Heavy Melting Steel Scrap Annual Price Volatility
0.1
0.12
0.14
0.16
0.18
Jan
Feb
Mar Ap
rM
ay Jun
Jul
Aug
Sep
Oct
Nov
Dec
HM
S pr
ice
per p
ound
($)
Monthly Price Volatility
2018 monthly prices 2018 average price
2017 monthly prices 2017 average price
0
0.3
0.6
0.9
1.2
2013 2014 2015 2016 2017 2018
Al p
rice
per p
ound
($)
AluminumAnnual Price Volatility
0.8
0.9
1
1.1
1.2
1.3
Jan Feb Mar Apr May Jun Jul AugSep Oct Nov Dec
Al P
rice
per p
ound
($)
Monthly Price Volatility2018 monthly prices2018 average price2017 monthly prices
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In this analysis (Figure 9), cobalt has emerged to be the material of highest concern. Cobalt has a high negative value for the social metric (representing significant political instability in regions where material production is concentration), largely due to the dominant production of cobalt in the Democratic Republic of the Congo, which is a country known for its socio-political issues. Cobalt is increasingly considered to be similar to ‘conflict materials’ as it is mostly sourced from a geographical location characterized by socio-political conflicts. The materials classified as conflict materials are Tungsten, Tantalum, Tin and Gold, because economic activities associated with their production may contribute to conflict activities in producing countries. Table 7 presents production details about conflict minerals and their potential substitutes.
Figure 9: Comparison of the HHI with and without socio-political weighting factors. Materials with high HHI have greatest risks due to supply chain concentration in a few countries. Materials with highly negative WGI-PSAV HHI have greatest risks because the supply chain concentration aligns with politically unstable regions.
-1 -0.8 -0.6 -0.4 -0.2 0 0.2 0.4 0.6 0.8
CoMgHg
REEsSbGrTeTaVIn
PdAl
PbFeBaPtZnCdTiCrAgMnNi
SnCuAuGaLi
Geographical concentration weighted for socio-political instability (WGI-PSAV HHI)Geographichal concentration (HHI)
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Table 7: Understanding Conflict Minerals- Tungsten, Tantalum, Tin, Gold and Cobalt and their potential substitutes.
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Part 3: End-of-life materials management The sustainability challenges and opportunities of managing materials when CT products reach their end of life (EOL) depend on many factors, including characteristics of the material, e-waste recovery infrastructure, waste management policy, consumer collection rates, and performance of available recycling technologies. The metrics used in this study to measure sustainability in EOL of CT materials are: theoretical recycling rate, material price, US import reliance, open loop potential, closed loop potential, material dilution and direct ecotoxicity. Theoretical recycling rate (recycling efficiency) is the amount of old scrap recovered and reused relative to the amount available to be recovered and reused (after collection), which is the percentage of total waste generated that is recycled (See Figure 10). Open loop potential reflects secondary material availability, in terms of the fraction of the apparent material supply that can be obtained from secondary sources on an annual basis. These secondary sources may include “new” scrap (recovered during material processing) and “old” scrap (recovered after consumer use). Closed loop potential reflects the theoretical ability to achieve circularity in CT products through recycling. It is calculated here as the ratio of end-of-life waste material relative to material demand in the same year. Values are taken from the waste flow and material demand estimations from Phase 1 of SMM project. Material dilution represents the potential challenge extracting a material from the waste stream due to its low concentration relative to the total mass of the waste stream. Values are again taken from the Phase 1 research and are calculated based on the mass of a given material relative to the total mass of electronic waste flow at that time. Another factor considered is U.S. Import reliance, the percentage of a material consumed in the US that is imported from another country. This metric can be used as motivation for developing a stable, secure domestic mineral supply chain.
Measuring social risks of material production
Key Findings:
• Cobalt is a material with higher risk to sustainable production due to its production concentration in the Democratic Republic of the Congo, which has concerns related to political instability
• Magnesium, mercury, REEs and antimony also pose considerable risk to sustainable production, suggesting a need to diversify production, source secondary materials, or choose material substitutes.
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Figure 10: The metal life cycle – for this research, recycling rate is the ratio of material recovered to material available to recycle in the U.S. Open loop potential is the ratio of total scrap input to total metal consumed in US (Source: Gradeal et al. 2011). The results for the analysis of sustainability in EOL management of CT materials are presented as a heat map in Table 8. Recycling rates have emerged to be a concern for many critical materials such as indium, lithium, and REEs. Import reliance is also high for many critical metals and REEs. As per the USGS (2017), China is the single largest source of material imports for the U.S, including for 24 out of the 47 mineral commodities that the United States is more than 50 percent reliant on foreign sources. Reducing import reliance through recycling is viewed as a key opportunity for enhancing the supply chain for many materials that are crucial for the U.S. economy and national security.
Materials Current
Recycling Rate
Price
Import Reliance:
US Perspective
Open Loop Potential
Closed Loop Potential Dilution
Base
Met
als
Al Cu Mg Fe Ni Zn Ti
Prec
ious
Met
als
Au Ag Pd Pt Rh Ru Ir
Os (continued next page)
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Crit
ical
met
als
Sb Ba Co Ga Gr In Li
Mn Ta Te Sn V
REE
s
La Ce Pr Nd Eu Gd Y Tb Dy
Haz
ardo
us
Met
als
Pb Hg Cr Cd
Table 8: Measuring sustainability of EOL for common CT materials. The heat map uses dark blue to signify lower recovery and recycling potential and light blue to show better EOL management. Gray indicates unavailable data. For results in absolute numbers please refer Appendix Table A4.
Materials Current
Recycling Rate
Price
Import Reliance:
US Perspective
Open Loop Potential
Closed Loop Potential Dilution
Measuring sustainability issues for EOL material management
Key Findings:
• REEs present a significant challenge at EOL, as they currently have low recycling rates, high import reliance, and are highly diluted or dissipated in the e-waste flow since they are present only in small quantities per CT product.
• Critical metals like indium, lithium and gallium are priorities for developing recovery methods, given their importance to the CT sector
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The relative dilution of materials in the e-waste is a factor that influences the recycling rate. High dilution represents a small concentration relative to all other materials from which a desired material must be separated and purified. Recent trends in dematerialization and increased adoption of small mobile products have resulted in changes to the degree in which materials are diluted or dissipated across products requiring EOL management. Figure 11 presents the changes in material dilution over time for gold contained in printed circuit boards, cobalt present in batteries, and neodymium present in hard drive magnets. Among these three materials, dilution is a particular challenge for gold and neodymium, which are found in smaller quantities compared to cobalt. Gold is increasingly diluted in the waste flow as products, and the circuit boards they contain, undergo miniaturization. Cobalt and Neodymium have been increasing in the waste flow due to increased prevalence of mobile products such as laptops, tablets, and smartphones. However, values are starting to level off, due to product lightweighting trends. Changes in material dilution indicate need for better recycling technologies and infrastructure to efficiently reclaim and recover these critical materials which are important for the economy.
Figure 11: Tracking changes in material dilution in e-waste over recent years for cobalt, gold, neodymium which are materials of interest in terms of recycling. Another reason to recycle EOL products is the potential eco-toxicity of materials if they are released due to improper handling or recycling. Among the materials analyzed in this study, freshwater aquatic eco-toxicity was identified for the materials in the table to the right, presented as a heat map. Dark blues indicates higher eco-toxicity, while light blue indicates lower eco-toxicity. Materials not shown have no established eco-toxicity values, which doesn’t exclude their potential harm, but rather indicates that the organismal testing required to create these values has not been performed (common for emerging materials).
Using SMM metrics to identify potential sustainability solutions Application of the SMM demonstrated potential “hotspots,” or specific areas of concern, for different types of materials. Some of these possible hotspots include:
• Dependency on critical metals that are in high demand in other industries. Example: REEs, cobalt, lithium
• Geographic concentration of production. Example: Global dependency on China for production and supply of raw materials
• Environmental impacts of producing primary materials. Example: Base metals (high use rate in all electronics) and precious metals (high impact per unit mass).
• Social risks from sourcing materials from countries with socio-political instability. Example: Cobalt from DRC
• Low recycling rates, even though enough end-of-life material is available to meet demand, in either closed or open loops.
These findings help guide development of potential solutions. While this report does not prescribe specific strategies, it does provide analyses that may help evaluate a broad solution space that responds to the challenges identified above. For example, reducing material use can be achieved through dematerialization or substitution with a lower impact alternative. Increasing recycling of key materials can reduce supply chain impacts while also limiting reliance on potentially vulnerable supply chains. Supply chain risks can also be mitigated by identifying alternate sources or diversifying the mix of countries from which resources are mined. The following section demonstrates some of the potential opportunities for realizing sustainable gains in CT material profiles Opportunities in material substitution and dematerialization are illustrated by a demonstration of material profile and carbon footprint of materials contained within a laptop computer.
Figure 12: Comparing the average material composition of a typical 14-inch laptop to the relative contribution to total material carbon footprint (supply chain greenhouse gas impact of producing all materials contained in the average laptop bill of materials).
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This comparison shows that even though contribution of aluminum to total laptop mass is lower than that of plastics, it has a much higher contribution to total carbon footprint of the product. These results are due, in part, to the choice of primary aluminum, which is an extremely energy-intense material to produce. Though mass contribution of precious metals (Au, Pt, Pd) is not significant, their individual impacts are high enough to be significant at the product scale. Battery materials (Co, Li) are noticeable in mass as well as in environmental impacts. To test the potential reduction in environmental risks through material substitution, the “typical 14-inch laptop” is re-analyzed as having a aluminum case. Results are also compared to producing the casing with aluminum containing recycled content (up to the global average).
Figure 13: Comparing carbon footprint of laptops with different casing materials: plastic, aluminum, and recycled aluminum. These results have two important implications. First, dematerialization does not naturally lead to environmental savings, if it results in use of a higher impact material (even if the net mass is reduced). Second, dematerialization, substitution, and recycling can be viewed holistically for improved results, such that material choices comprehend both potential benefits and impacts. In the above example, a case containing recycled aluminum reduced the material-specific carbon footprint of the laptop about 30% relative to the original design. Taking a broader view, the life cycle carbon footprint of this type of laptop has been previously estimated by Dell to be about 350 kg CO2-eq, most of which is attributed to manufacturing and consumer use (Stutz, 2010). Using the above results, the material contribution is only about 5% of that total, signifying that other strategies may lead to greater net environmental improvements, at least when considering carbon footprint. On the other hand, material choice can indirectly contribute to these improvements. Consumers tend to value and maintain metal-cased products for longer, thus offsetting some demand for new products and the attendant environmental impacts from manufacturing.
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The potential benefits of recycling, expressed for simplicity here in terms of carbon footprint, are shown below in Table 9. It is clear that the greatest benefits can be achieved by recovery of high impact materials. However, many such materials are recycled at a relatively low rate, due to technological limitations, low collections after consumer use, or lack of a market at sufficient volume for the recovered supply.
Table 9: Theoretical environmental savings through recycling for base metals and precious metals Materials can also be sourced through alternate supply chains, which may have lower environmental or social risks relative to current practices. The following set of graphs presents a series of maps, on which are highlighted all countries that produce CT materials of any time. Darker blue signifies greater impact, lighter blue lower impact, for three sustainability issues: water scarcity, carbon intensity of electricity production, and socio-political instability.
Figure 14a: Water scarcity footprint (WSF) of 1m3 water consumed in producer countries
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Figure 14b: Carbon footprint (CF) of 1kWh of electricity produced in producer countries
Figure 14c: Socio-political instability of producer countries assessed by the World Governance Indicators on Political Stability and the Absence of Violence (PSAV).
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These results highlight potential issues and opportunities in material sourcing, wherein some countries have stable governance and low risks of supply disruptions (e.g., the U.S. and Australia), but slightly higher carbon and water impacts of industrial activities taking place there. Countries like Russia have lower environmental impacts but larger risks of political instability leading to supply chain disruptions, an important consideration for CT business continuity. Material case studies The results presented thus far applied a consistent set of metrics across as many materials for which data could reliably be collected and analyzed. Some materials are characterized by sustainability impacts that suggest a need for additional investigation and insight. Other materials simply lacked sufficient data to include in all characterizations presented above. Therefore, this section presents a select set of material case studies, chosen and developed to highlight a few key issues relevant to CT materials. Case Study 1: Battery materials (Cobalt, Lithium) Lithium-ion batteries (LIBs) are in high demand globally, due to increased adoption of mobile devices and high growth in the electric vehicle (EV) industry, which employs LIBs for energy storage. Though different chemistries of LIBs are now in the market, lithium cobalt oxide (LCO) comprises the largest share of the overall LIB market, as it is the chemistry best suited for CT applications currently. Key raw materials in LIBs include lithium, graphite, cobalt, manganese and nickel. Due to high demand for LIBs, securing reliable and unhindered access to these raw materials have become a concern for global economies. Battery materials were added to DOE’s critical mineral list in 2018. Due to high economic importance and supply risk, cobalt was also included in the EU’s Critical Raw Material list.
Key issues for battery materials:
• Co has a highly concentrated supply chain, including concentration in regions known for political instability
• Both Li and Co have experienced price volatility in recent years. • Demand continues to increase due to growing electric vehicle industry. • Cumulative recycling rates are low even though recovery technology exists.
Figure 15. Compounded annual growth rate of EVs and battery materials. Source: BBVA Research and Bloomberg New Energy Finance
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While geological scarcity is not a major issue for cobalt or lithium, supply risk due to geographical concentration of production is high for cobalt as two-third of total cobalt is mined in the DRC which is reputed for socio-political instability. High demand and fluctuating price are a concern for both lithium and cobalt. Figure 16 shows the increasing trend in cobalt and lithium price, wherein cobalt price more than doubled in 2017, while lithium price increased 60% in 2017 compared to the previous year. With the recent categorization of cobalt as a strategic mineral by DRC government, cobalt prices are expected to continue to increase in 2019. Low recycling rate is another area of concern for both cobalt and lithium, due to inefficient collection rates, as well as lack of markets and infrastructure for recycling batteries. A combination of different sustainability strategies, including material substitution, exploring alternate supply chains, and recycling end-of-life batteries will need to be employed to reduce dependency on foreign sources for battery metals and ensure their continuous supply. Ongoing research is focused on developing battery chemistries with reduced quantities of cobalt without compromising energy density. There are tradeoffs in substitution, as it may come at the cost of energy density which is a key feature of LIBs that makes them attractive in high power applications like electric vehicles. However, for some CT applications, a small decrease in energy density through material substitution may be a viable option. Potential substitutions below are taken from Graedel et al. (2013).
Substitution Tradeoff Li Nickel-metal hydride batteries (rechargeable batteries
substitute), and zinc for primary batteries Altered performance, high impact materials
Co In LIBs, using iron-phosphorous, manganese, nickel-cobalt-aluminum, or nickel-cobalt-manganese chemistries can reduce the use of cobalt.
Altered performance, possibly safer, minimal recycling value
Currently DRC dominates mine production with around 60% contribution to global production of cobalt. However, in the case of global reserves, Congo (DRC) holds only 25% of the reserves while the remaining is distributed among many countries which may have fewer supply chain risks (Figure 17). For example, Australia has around 1.2 million metric tons of identified cobalt reserves, which indicates a potential to explore alternate supply chains. However, other factors affecting the feasibility of changing supply chain would need to be addressed in parallel.
Only 10% of total cobalt occurs as primary metal. Except for artisanal mining in DRC, cobalt is mostly mined as a byproduct of Cu or Ni, which implies that when their prices change, it for may affect mine production of cobalt even when Co demand is high.
07
14212835
2013 2014 2015 2016 2017 2018
Pric
e($
per p
ound
)
Price ($ per lb)-Cobalt
Price ($ per lb)-Lithium
Figure 16: Price volatility in cobalt and lithium markets
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Figure 17a (left): Current cobalt production distribution; Figure 17b (right): Cumulative cobalt reserve distribution While two-thirds of cobalt is mined in DRC, most is ultimately refined in China. Recovering cobalt from end-of-life products through recycling is important to diversify this supply chain. While current recycling rates of lithium is almost zero, there is considerable effort aiming to recover cobalt. Cobalt contained in purchased scrap constituted around 33% of total consumption in US in 2017. Even though cobalt recycling from scrap is considered to be economically viable, LIB recycling is rare, with only a few companies investing in recycling technologies, although the market is beginning to grow. However, lab scale recycling yields (Table 10) prove that ongoing research is on the right path in developing better recycling technologies for material recovery from spent batteries.
Case 2: Rare Earth Elements (REEs) The 15 elements in the periodic table called lanthanides together with scandium and yttrium are termed as rare earth elements (REEs). While REEs are not rare in terms of crustal abundance,
Battery Materials
Current Recycling
Yield
Lab Scale Yields (Mid)
Lab Scale Yields (High)
Co 68% 80% 99%
Li 0% 55% 10%
Al 42% 55% 98%
Ni 57% 99% 99%
Mn 0% 92% 98%
Other battery concerns
Most LIBs use a flammable liquid electrolyte which increases the risk of fire if the batteries are not treated properly at end-of-life.
Incidents of batteries sparking or catching fire have been reported recently, leading to greater concern about safe handling and transportation.
Replacing liquid electrolytes with solid electrolytes is promoted as a potential solution. However, solid state battery technology is currently in the development stage and it may take a while before they are adopted in consumer technologies. Other energy storage methods, like ultracapacitors and wireless charging are being explored.
Table 10. Battery materials recycling yields, defined as the ratio of material recovered to total material input to a recycling process (does not account for collection, etc.)
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they are called so because concentrated ore deposits of REEs are uncommon, which makes their extraction difficult. Due to their unique magnetic, luminescent, and catalytic properties, REEs are essential to a wide array of applications in defense, clean energy and consumer technologies. One of the most important uses of REEs is in permanent magnets used in “green” technologies, such as electric cars, hybrid cars, and wind turbines. As a result, demand for REEs has grown in the last five years (Figure 18), a trend expected to continue in the near future. In consumer technologies, they are critical to permanent magnets of hard drives, nickel-metal hydride batteries, and lamp phosphors. The five REEs identified by DOE as most critical are Neodymium (Nd), Europium (Eu), Terbium (Tb), Yttrium (Y). Figure 19 presents DOE’s criticality matrix as reported by Binnemans et al. (2013), which takes into account the importance of a material for a technology (and the lack of functionally equivalent substitutes) and the risks of supply disruptions.
Potential REE supply chain concerns are compounded by the ‘balance problem’: REE oxides occur in different ratios within the iron ores in which they are commonly found. Some are abundant while others are not. For example, primary mining of REE ores for neodymium generates an excess of REEs that are not in high demand, such as lanthanum and cerium, which then require a market but create an artificial price signal. Recycling has been touted as a strategy to manage overproduction of REEs that have limited demand (Binnemans et al. 2013). Geographical concentration of production is a major concern for REEs as 90% of REEs are produced in China, which is also the highest consumer of REEs that are integrated into
Key issues for rare earth elements:
• Geographical concentration of production is a potential issue, as China controls the 90% of REE supply.
• Consumption for some REEs (Dysprosium, Europium, Neodymium and Samarium) consumption is driven by electronics sector.
• Poor EOL management, as shown by low recycling rates, dilution in waste stream, high import reliance (100%).
80
100
120
140
Prod
uctio
n of
REE
ox
ide
(thou
sand
met
ric
tons
)
REE global mine production
Figure 18. Increasing production of REEs Figure 19. DOE’s criticality matrix
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electronic and automotive applications. With China’s increasingly tight export quota due to domestic demand and ongoing US-China trade tensions, China’s control of the REE value chain presents clear supply risk for REEs. While recycling REEs can help meet the increasing demand and reduce import reliance, less than 1% of REE are being recycled. Another reason to recycle REEs is that the deposits of these minerals often contain radioactive elements uranium and thorium, which makes mining and extraction environmentally hazardous. REEs are critical in many applications due to their unique physical and chemical properties. Therefore, substitution options are generally less effective:
One strategy to minimize potential sustainability risks to REE supply is to explore alternate supply chains in countries with enough reserves for the minerals. Figure 20 a and b shows production distribution of REEs side by side with the distribution of global reserves. While 90% of production is concentrated in China, only 36% of global reserves are in China. While Australia holds only 3% of global reserves, it contributes over 15% to total REE production. With recoverable reserves throughout the world as seen in Brazil, Vietnam and Russia (Figure 20b), there is clearly potential to explore alternate supply chains for REEs, if economics permit.
Figure 20a (left): Current REE production distribution; Figure 20b (right): Cumulative REE reserve distribution
EOL products considered to have high potential for REE recovery include lamp phosphors, nickel-metal-hydride batteries, and permanent magnets. Recent research has emphasized the recovery of neodymium and dysprosium from magnets found in hard disk drives, speakers, EV motors, and wind turbines. While different methods are explored in laboratories, only a tiny fraction of REEs in EOL products is recycled today, with the rest being dispersed or removed from the materials cycle. The main barrier to REE recycling is the high cost of separation and purification of the REE mixture obtained from EOL CT products. However, ongoing research on
REE recycling and developing markets for recycled materials is expected to grow as a potential solution to the increasing reliance on these materials in modern technologies. Case Study 3) Plastics Consumer technology products represent an annual consumption of over 200,000 metric tons of plastics, which ultimately make up 25% of the e-waste flow. While around 12 types of polymers are found in electronics, some are more common, including ABS (Acrylonitrile-butadiene-styrene copolymer), HIPS (Polystyrene, high impact), PA-(Polyamide), PS (Polystyrene) and PC (Polycarbonate). In this study, the potential sustainability issues with different types of plastics used in CT products were analyzed. Table 11 presents a heat map with comparisons of annual production, price and environmental issues associated with production of different types of plastics used in consumer technologies
Table 11. Measuring sustainability issues associated with plastic production. In the case of environmental footprint, ABS, HIPS, and PS have lower embodied impacts that other polymers included in this study. While the heat map shows price variation among different plastics (PVC and PS having relatively lower price), the actual price difference between types of plastics is minimal. The average price per pound of plastic is 1$ per pound.
Materials Annual
Production Price Carbon
Footprint Water
Footprint Energy
Demand
Mineral Resource Demand
ABS
HIPS
PA
PS
PC
PVC
PMMA
Key issues for plastics:
• Poor EOL management and low recycling rates are compounded by contamination, which presents technical and economic challenges in e-plastics recycling.
• Recent bans and subsequent disruption in e-plastic export market to China, Vietnam and other Southeast Asian countries.
Plastics Other Materials in E-waste
Plastics form 25% of electronic waste
Plastics in CT products:
A typical printer is made up of more than 50% plastics, while laptops and flat panel display products contain around 25% plastics.
One challenges to e-plastics recovery is the wide range of plastics used in CT products. The mixed stream is challenging to sort and identify, but mixed plastics have low economic value. Another roadblock to e-plastic recycling is the use of brominated flame retardants which are added to e-plastics to enhance their resistance to fires. The issues with end-of-life management of plastics has aggravated recently with countries like China implementing bans on import of recovered e-plastics, heavily disrupting the downstream markets of EOL plastics. Even though CT products have become smaller and lighter with ongoing dematerialization trends, plastic content in the e-waste stream has not decreased. In fact, as Figure 21 shows, the plastic content relative to other e-waste materials has been slightly increasing, underscoring the need for e-plastics recovery and recycling. The plastic content in e-waste itself is enough to meet demand in the CT sector, if technically and economically possible to close that material loop. Figure 22. compares the total e-plastic waste generation and e-plastic demand over the years, showing the potential to close the loop on plastics in CT sector.
Figure 22: Comparing plastic waste flow with plastic demand in CT sector. The environmental benefits achievable through recycling for different types of plastics is shown in Table 12. Environmental savings through recycling is highest for polyamide (PA) and polycarbonate (PC) polymers. However, the recycled content in current plastic supply is low, especially for PA and PC. Increased domestic management capability, including recycling technologies and infrastructure, is required to take advantage of these savings.
0
150,000
300,000
450,000
2000 2003 2006 2009 2012 2015 2018
E-Pl
astic
s D
eman
d an
d W
aste
flow
(met
ric to
ns)
Plastics in E-waste E-Plastics Demand
15%
20%
25%
30%
2000 2003 2006 2009 2012 2015 2018
Plas
tic c
onte
nt in
e-w
aste
Figure 21. Increasing plastic content in e-waste
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Table 12. Measuring sustainability issues associated with plastic production. Case Study 4) Nanomaterials
With the increasing adoption of consumer technology, material innovations aim to meet consumer demands through enhanced performance and the design of the components used in these products. One recent area of material innovations is in the development of engineered nanomaterials. Nanomaterials have at least one dimension less than 100 nm and have enhanced strength, opto-electric, thermal, and chemical properties associated with this quantum scale. This section overviews key issues in several nanomaterials common to consumer technology and related applications, including quantum dots, carbon nanotubes, graphene and silver nanowires. Quantum dots (QDs) are emerging cadmium-, zinc-, or indium-based nanoscale semiconductor materials compounds, and with unique fluorescence properties that have the potential to replace existing LCD technology (indium tin oxide-based displays). Many of the QD-enabled technologies on the market are cadmium-based compounds. Cadmium being a toxic material raises concern over its use in the consumer products. An alternate technology being implemented in the market to replace cadmium are indium phosphide quantum dots. However, there are tradeoffs in using indium-based compounds. One study shows that primary energy requirement for production of indium QDs is higher than cadmium QDs (Figure 23). In addition, both materials have broader sustainability considerations associated with their supply chain.
Plastics
Energy demand for
primary production
(MJ)
Energy savings
from recycling
(%)
Carbon footprint for
primary production (kgCO2eq)
Carbon savings
from recycling
(%)
Recycled fraction in
current supply
ABS 95 51% 4 26% 4%
PA 123 65% 8 68% 1%
PP 79 37% 3 - 6%
PE 81 38% 3 7% 9%
PC 109 61% 6 58% 1%
PET 85 54% 4 40% 21%
PVC 59 39% 3 14% 2%
PS 97 51% 4 25% 6%
PLA 52 29% 4 39% 1%
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Figure 23. Cradle-to-gate cumulative energy demand for each display type’s market segment to understand the energy needs for large scale adoption (Figure taken from Chopra et al. 2017)
Indium is most commonly extracted as a by-product of zinc production. The amount of metal extracted depends on the indium content in zinc ore, but is relatively low, usually between 100 to 2730 parts per million. This limitation in primary production raises uncertainty in the indium supply to meet the increasing demand. Asia is the major producer of indium, and leading producers are China, Japan and North Korea, contributing more than 80% of indium production. Production of indium in these top countries is only sufficient to meet their demand, thus making it difficult to meet the rest of the global indium demand. However, the global reserves show that the United States and Peru have reserves which are not explored completely. This indicates the potential for increasing the supply of indium by sourcing indium from these countries, recognizing limiting factors such as economic, political, technological and social feasibility.
Key issues for quantum dot technology:
• Geological scarcity is an issue for In and Cd. • Both In and Cd have low recycling efficiency. • Demand for In and Cd continues to increase due to increasing
adoption of consumer electronics.
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Figure 24a (left): Current indium production distribution; Figure 24b (right): Cumulative indium reserve distribution More than 70% of indium produced is used in the displays of consumer electronics. Therefore, end of life recycling is a potential opportunity for closing this material loop. However, current global recycling of indium at the end of life products is very low (<1%) because of poor collection rates and lack of metal tracing in the waste. There is an opportunity for improving the recycling rates of indium by optimizing collection programs for end of life products, and improving recycling technology to recover materials from end of life products. Cadmium is also primarily extracted as a by-product of zinc production. Like indium, the amount of cadmium content in the ore is low, ranging from 200 to 14,000 ppm. Most of the primary cadmium production is carried out in Asia, and the leading producers are China, Japan, and Republic of Korea, contributing to nearly 60% of global production. Global reserves show that there is an opportunity to shift cadmium production, although that may not be a solution to other sustainability challenges, given the material’s inherent toxicity.
Figure 25a (left): Current cadmium production distribution; Figure 25b (right): Cumulative cadmium reserve distribution In 2015, cadmium was declared a toxic metal by the EU and banned from use in consumer products. Cadmium and its compounds have been declared carcinogenic to humans. Since then, there has been an effort to find a substitute for cadmium. One of the best substitutes identified so far is indium. However, as discussed in the above section, this is an imperfect substitution. Recent scientific literature have proposed zinc- or silicon-based QDs. Ongoing research is required to understand the properties of these substitutes and to what extent they will influence the performance of the technology. Nearly 70% of cadmium produced is used in nickel cadmium batteries, many in CT applications. Consequently, spent batteries can be a major potential source of recovering cadmium. Currently, recycling efficiency of the cadmium is only 15%, due to the small size of batteries recycled. Improved recycling technology may also contribute to reducing the amount of cadmium released into the environment and the associated effects on health and ecosystems.
Table 13: Comparison of Cadmium and Indium
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Carbon nanotubes (CNTs) are carbon-based nanomaterials with significant potential for use as an anode material for lithium-ion batteries because of their electrochemical and mechanical properties. Research has been focused on understanding their properties, the potential to replace existing technologies, and resource use for CNTs production. However, environmental characterization data is scarce for CNTs, thus the data presented here is limited to cumulative energy demand (a widely used proxy for supply chain impacts). Figure 26 shows that the energy demand per kg of single walled CNTs is significant, almost 2,000 times higher than producing an equivalent mass of aluminum. These energy inputs, if generated by fossil fuel sources, would also contribute to significant carbon and water footprint and to high costs of material production.
Figure 26: Cumulative energy demand of nanomaterial production (from Upadhyayula et al. 2012) However, it should be noted that the material consumption of carbon nanotubes is far lower than aluminum and steel in consumer electronics. Therefore, impacts of carbon nanotubes might not be as significant when considered per product or sector basis. In addition to the supply chain impacts, studies based on lab data suggest that CNTs may contribute to toxicity if released uncontrolled into the environment. As an emerging technology, a full evaluation of the impacts does not yet exist but should be prioritized if CT products move to adopt these technologies. Graphene (a carbon-based nanomaterial) and silver nanowires (a metallic nanomaterial) are also being proposed for product integration because of their unique properties, including flexibility, high conductivity, and light weight. Research has suggested their use in flat panel displays because of their flexibility and as an anode in lithium-ion batteries for improving the storage capacity and lifetime. Figure 26 demonstrates that while the impact of producing graphene is less than that of carbon nanotubes, it is still significantly higher than comparable CT materials. Limited data available on nanowires suggest they are likely to present similar risks.
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Conclusions Technological innovations in the consumer technology industry are enabled by a broad spectrum of materials. The continuous availability and sustainable use of these materials is closely linked to sustainability and business continuity of the CT industry. Therefore, it is necessary to proactively identify potential risks in sustainable sourcing and management of materials critical to the industry. To this end, this study has studied and quantified potential sustainability risks throughout the life cycle of common materials used in CT products, using sustainability metrics identified through review of published academic literature, industry and government reports and integration of stakeholder perspectives. This study provides comprehensive knowledge about materials through quantitatively assessing sustainability concerns from the physical availability of resources through material extraction and refining through ultimate end-of-life management. Results are intended to identify hotspots that could inspire future innovation beneficial to the growth of the CT industry. Case studies were also included to add greater insights on materials of potential (REEs, battery materials) and materials that could not be included in general sections due to the lack of comparative data (plastics, nanomaterials). Among the materials analyzed, some are particularly critical to the growing consumer technology sector, yet face uncertain sustainability concerns. Physical availability for indium, geographic concentration of production for cobalt and REEs, environmental impacts of production for precious metals, and price fluctuations for critical metals are the key hotspots identified. These represent the greatest potential for sustainable innovation, particularly to offset impacts that may occur as other industries increasingly demand these materials. End-of-life management is a concern for almost all materials critical to the CT industry. The ‘closed loop potential’ for most of these materials is high, indicating that the e-waste stream could provide a consistent feedstock for future material demand, provided that significant improvements can be realized in recycling technology and infrastructure. Closing the loop on materials through recycling is a potential strategy that can mitigate all the aforementioned areas of concern. However, to ensure sustainable material use in the CT industry, a combination of different strategies need further exploration, via material substitution, alternate supply chains, and material recycling. This study provides the essential data to identify tradeoffs and prioritize the strategies that offer the greatest potential for each material.
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(Data Source: USGS; Closed Loop Potential and Dilution- calculated based on SMM Project Phase1 Baseline Model Results). Notes: Precious metals Iridium, Ruthenium, Osmium- Not included due to data unavailability.
(Data Sources: Production and Price (Ashby (2015), Environmental Impacts (ecoinvent Database, Simapro)
Table A5: 14-inch laptop average bill of materials- component level (Plastic casing-336g)
Aluminum Copper Steel Plastic Battery PCB Flat panel glass Others Total Mass (g)
285 62 224 986 265 355 208 64 2449 (Data Source: Product disassembly in the laboratory)
Table A6: 14-inch laptop average bill of materials- component level (Al casing-473g)
Aluminum Copper Steel Plastic Battery PCB Flat panel glass Others Total Mass (g)
758 62 224 650 265 355 208 64 2585 (Data Source: Product disassembly in the laboratory)
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Table A7: Laptop Case Study: Material contribution (materials of interest) to total mass and environmental Impacts.
Laptop Case Study- Detailed Material Composition (g)
Material Plastic Casing -Mass (g) Al Casing- Mass (g)
Al 3E+02 8E+02 Cu 1.6E+02 1.6E+02 Mg 5.5E-01 5.5E-01 Fe 4.4E-01 4.4E-01 Ni 5.6E+00 5.6E+00 Zn 4.3E+00 4.3E+00 Au 1.3E-01 1.3E-01 Ag 4.6E-01 4.6E-01 Pd 4.2E-02 4.2E-02 Pt 7.8E-03 7.8E-03 Sb 1.2E+00 1.2E+00 Ba 7.1E-02 7.1E-02 Co 4.8E+01 4.8E+01 Ga 1.2E-02 1.2E-02 Gr 4.1E+01 4.1E+01 In 3.0E-02 3.0E-02 Li 5.7E+00 5.7E+00
Mn 4.4E-01 4.4E-01 Ta 6.1E-02 6.1E-02 Sn 1.0E+01 1.0E+01 Ln 7.9E-04 7.9E-04 Ce 5.2E-04 5.2E-04 Pr 1.5E-05 1.5E-05 Nd 2.1E+00 2.1E+00 Eu 9.4E-04 9.4E-04 Gd 7.3E-05 7.3E-05 Y 1.3E-02 1.3E-02 Tb 2.7E-04 2.7E-04 Dy 6.0E-02 6.0E-02 Cr 1.2E-01 1.2E-01 Cd 7.7E-02 7.7E-02
Plastics 1.0E+03 6.3E+02 (Data Source: Product disassembly in the laboratory and published literature-Buchert et al (2012), Oguchi et al (2007), Wang and Gaustad (2012), Cucchiella et al (2015)). Notes: Precious metals- Rhodium, Iridium, Ruthenium, Osmium- Not included due to data unavailability.
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Table A8: Geographical concentration (HHI) and Geographical concentration weighted for socio-political stability (WGI PSAV weighted HHI).
Materials
Geographical Concentration of
Production (HHI Index)
Geographical Concentration weighted
for Socio-Political Stability
(WGI PSAV weighted HHI)
Al 0.31 -0.14 Cu 0.16 0.06 Mg 0.72 -0.40 Fe 0.28 -0.12 Ni 0.10 -0.01 Zn 0.20 -0.08 Ti 0.26 -0.05 Au 0.13 0.07 Ag 0.13 -0.04 Pd 0.30 -0.17 Pt 0.51 -0.10 Sb 0.55 -0.31 Ba 0.19 -0.11 Co 0.36 -0.73 Ga 0.25 0.12 Gr 0.45 -0.25 In 0.30 -0.19 Li 0.32 0.21
Mn 0.18 -0.02 Ta 0.21 -0.23 Te 0.47 -0.24 Sn 0.05 -0.01 V 0.37 -0.21
(Data Source: Calculated based on geographical concentration data from USGS and WGI-PSAV from World Bank database. Notes: Precious metals- Rhodium, Iridium, Ruthenium, Osmium- Not included due to data unavailability)
The HHI for production concentration is calculated for specific materials based on the equation:
where N= the number of producing countries, Xi = the quantity of a given material produced by each country, and X = the total world production of that material. HHI value is always positive, with a higher value indicating higher market concentration which is undesirable. WGI-PSAV metric is the “World Governance Indicator of Political Stability and Absence of Violence.” In addition to considering how concentrated the market for a given material is, this metric also considers how stable those countries that are producing the material are. The WGI-PSAV weighting metric can be positive or negative (with negative indicating less stability and more violence). Therefore, any high negative values are very undesirable, low negative values are still undesirable, high positive
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numbers are ambiguous, and low positive numbers are desirable. WGI PSAV weighted HHI is calculated by multiplying each country’s HHI value for a given material by the WGI-PSAV score for that country, the equation is:
where N= the number of producing countries, Xi = the quantity of a given material produced by each country, X = the total world production of that material, and Si = the WGI-PSAV score for each country.
Phthalate plasticizers 1.0E-02 7.7E+01 2.0E+00 (Data Source: ecoinvent database- Simapro LCA Software; Flame retardants and Phthalates- modelled in Simapro based on lifecycle inventory data reported by Meyer & Katz (2016) and Li (2013) respectively.
