Decarbonizing world economies implies the deployment of “green technologies”, meaning a renovation of the energy sector towards using renewable sources and zero emission transport technologies. This ...renovation will require huge amounts of raw materials, some of them with high supply risks. To assess such risks a new methodology is proposed, identifying possible bottlenecks of future demand versus geological availability. This has been applied to the world development of wind power, solar photovoltaic, solar thermal power and passenger electric vehicles for the 2016–2050 time period under a business as usual scenario considering the impact on 31 different raw materials. As a result, 13 elements were identified to have very high or high risk, meaning that these could generate bottlenecks in the future: cadmium, chromium, cobalt, copper, gallium, indium, lithium, manganese, nickel, silver, tellurium, tin and zinc. Tellurium, which is mostly demanded to manufacture solar photovoltaic cells, presents the highest risk. To overcome these constraints, measures consisting on improving recycling rates from 0.1% to 4.6% per year could avoid material shortages or restrictions in green technologies. For instance, lithium recycling rate should increase from 1% to 4.8% in 2050. This study aims to serve as a guideline for developing eco-design and recycling strategies.
•Green technologies require huge amounts of many different raw materials.•A methodology is presented to identify possible material bottlenecks.•Bottlenecks are assessed through reserves, resources and production data.•Annual increase in metal recycling rates to offset bottlenecks is calculated.
•Maximum production peaks of minerals can be obtained using the Hubbert peak model.•Factors influencing the reliability of Hubbert model are stressed.•The case of lithium was used to analyze the ...influence of changes in resources data.•The maximum production peak of 47 mineral commodities was obtained.•Twelve minerals could peak in the next 50 years assuming available resources.
Among the existing methodologies to assess future availability of mineral resources, the Hubbert peak model is a direct approach that can provide useful information about non-fuel mineral depletion using BAU production trends. Using lithium as a case study, the influence on the fluctuations on extractable resources has been analyzed. Accounting only for conventional lithium resources, the peak is only delayed less than two decades even if the most optimistic resources values are doubled. Additionally, using resources information obtained mainly from USGS data, the maximum production peak of 47 mineral commodities has been estimated. For two of them, the maximum theoretical production peak has already been reached, 12 could have theirs in the next 50 years and a total of 30 commodities could reach their maximum production peak in the next century. Many factors can influence these values, changes in future extraction trends, ore grade, exploration and new discoveries and more accurate data on resources. With this information the most crucial elements (i.e. those peaking soon) can be identified and be used to put more emphasis on policies regarding sustainable use of non-renewable commodities.
Mining industry requires high amounts of energy to extract and process resources, including a variety of concentration and refining processes. Using energy consumption information, different ...sustainability issues can be addressed, such as the relationship with ore grade over the years, energy variations in electricity or fossil fuel use. A rigorous analysis and understanding of the energy intensity use in mining is the first step towards a more sustainable mining industry and, globally, better resource management. Numerous studies have focused on the energy consumption of mining projects, with analysis carried out primarily in one single country or one single region. This paper quantifies, on a global level, the relationship between ore grade and energy intensity. With the case of copper, the study has shown that the average copper ore grade is decreasing over time, while the energy consumption and the total material production in the mine increases. Analyzing only copper mines, the average ore grade has decreased approximately by 25% in just ten years. In that same period, the total energy consumption has increased at a higher rate than production (46% energy increase over 30% production increase).
Moving towards a low-carbon economy will imply a considerable increase in the deployment of green technologies, which will in turn increase the demand of certain raw materials. In this paper, the ...material requirements for 2050 scenarios are assessed in terms of exergy to analyze the impact in natural resources in each scenario and identify which technologies are going to demand more resources. Renewable energy technologies are more mineral intensive than current energy sources. Using the International Energy Agency scenarios, from 2025 to 2050, total raw material demand is going to increase by 30%, being the transport sector the one that experiences the highest increase. Aluminum, iron, copper and potassium are those elements that present a higher share of the material needs for green technologies. Besides, there are five elements that experience at least a six-fold increase in demand in that period: cobalt, lithium, magnesium, titanium and zinc. Comparing those results with Greenpeace's AE R scenario, which considers a 100% renewable supply by 2050, this increase is even higher. Therefore, avoiding the dependency on fossil fuels will imply to accept the dependency on raw materials.
•Exergy flow analysis of the energy transition including mineral requirements.•Impact on primary resources of energy scenarios: IEA 450 and Greenpeace's AE R.•Identification of which technologies will demand more raw materials.•Assessment of 36 raw materials through exergy replacement costs.
•The mineral balance of the European Union is assessed through exergy analysis.•With exergy analysis the quality of the mineral resources can be accounted for.•Europe is more dependent on imports ...than perceived with conventional MFA.•Considering mineral quality can lead to better resource efficiency policies.
Material flow analysis is a key tool to quantify and monitor the use of natural resources. A very visual way to undertake such analyses representing the mineral trade is through Sankey diagrams, in which the mineral resources that are extracted, imported, exported, recycled and consumed within the given boundaries are represented with the arrows proportional to their respective quantities. Yet Sankey diagrams alone are not sensitive to the quality of the resources as they only reflect tonnage. This issue can lead to misleading conclusions and thereby not effective resource policies. A way to overcome this deficiency is representing the flows in exergy replacement cost (ERC) terms instead of tonnage. Exergy replacement cost is a concept derived from the second law of thermodynamics and assesses the exergy cost required to return with available technologies a given mineral to its initial conditions of composition and concentration in the mines where it was found, once it has been dispersed after use. Using this methodology, minerals are physically valued in terms of their respective scarcities and the effort (in exergy cost terms) required to produce them. Accordingly, in this paper the so-called exergoecology method is used to evaluate mineral trade and foreign mineral dependency in the EU-28 for 1995 to 2012. Using the year 2011 as a case study, it can be seen using this novel approach that 45.8% of the total input of minerals are imported resulting in lower values of self-sufficiency than if a traditional MFA were applied (0.45 for minerals and 0.41 for fossil fuels, in contrast to 0.79 and 0.52 obtained respectively when using tonnes). Analyzing 10 of the 20 minerals deemed critical by the European Commission, of the total internal production, 0.88% corresponded to critical minerals when data were expressed in tonnes and 3.19% when expressed in exergy replacement costs, highlighting their relevance respect to other minerals. This external dependency leaves Europe in a delicate situation regarding fossil fuels and non-fuel minerals supply highlighting the importance of recycling especially scarce minerals and searching for alternative sources.
This paper presents a thermodynamic vision of the depletion of mineral resources. It demonstrates how raw materials can be better assessed using exergy, based on thermodynamic rarity, which considers ...scarcity in the crust and energy requirements for extracting and refining minerals. An exergy analysis of the energy transition reveals that, to approach a decarbonized economy by 2050, mineral exergy must be greater than that of fossil fuels, nuclear energy, and even all renewables. This is because clean technologies require huge amounts of many different raw materials. The rapid exhaustion of mines necessitates an increase in recycling and reuse, that is, a “circular economy”. As seen in the automobile industry, society is far removed from closing even the first cycle, and absolute circularity does not exist. The Second Law dictates that, in each cycle, some quantity and quality of materials is unavoidably lost (there are no circles, but spirals). For a rigorous recyclability analysis, we elaborate the exergy indicators to be used in the assessment of the true circularity of recycling processes. We aim to strive toward an advanced economy focused on separating techniques and promoting circularity audits, an economy that inspires new solutions: an in-spiral economy.
A conventional passenger car demands almost 50 different types of metals, along other raw materials. Some of these metals, such as tantalum, indium, niobium or rare earths elements, are considered ...critical by the European Commission and many other institutions. Additionally, their functional recycling is practically absent. The transition to fully electric vehicles will require more electrical and electronic devices, motors and batteries, that will need an increasing amount of critical metals. A methodology has been developed to identify strategic elements for the automobile sector. This approach defines a variable called Strategic Metal Index (SMI) which is calculated for each metal. This index is the result of combining the following parameters: (1) Automobile sector demand with respect to world production; (2) known resources compared to total cumulative demand and (3) Supply risk. The index has been applied to 50 metals used by different types of vehicle powertrains. The assessment covers metal demand from 2018 to 2050 according to vehicle sales projections. Using this approach, the most strategic elements for the automobile manufacturing sector are Ni, Li and Co (used in batteries), Nd and Dy (permanent magnets), Tb (lighting and fuel injectors), Sb, Bi and and B (steel alloys, paintings), Au and Ag (electronics), In (screens) and Te (steel alloys, electronics). The search for substitutes, implementation of eco-design measures and the increase of the functional recyclability of these elements should be strongly encouraged in the sector.
Rising prices in energy, raw materials, and shortages of critical raw materials (CRMs) for renewable energies or electric vehicles are jeopardizing the transition to a low-carbon economy. Therefore, ...managing scarce resources must be a priority for governments. To that end, appropriate indicators that can identify the criticality of raw materials and products is key. Thermodynamic rarity (TR) is an exergy-based indicator that measures the scarcity of elements in the earth's crust and the energy intensity to extract and refine them. This paper uses TR to study 70 Mobile Phone (MP) Printed Circuit Boards (PCBs) samples. Results show that an average MP PCB has a TR of 88 MJ per unit, indicating their intensive use of valuable materials. Every year the embedded TR increases by 36,250 GWh worldwide -similar to the electricity consumed by Denmark in 2019- due to annual production of MP. Pd, Ta and Au embedded in MP PCBs worldwide between 2007 and 2021 contribute to 90% of the overall TR, which account for 75, 600 and 250 tones, respectively, and increasing by 11% annually. This, coupled with the short lifespan of MP, makes PCBs an important potential source of secondary resources.
Purpose
The safeguard subject of the Area of Protection “natural Resources,” particularly regarding mineral resources, has long been debated. Consequently, a variety of life cycle impact assessment ...methods based on different concepts are available. The Life Cycle Initiative, hosted by the UN Environment, established an expert task force on “Mineral Resources” to review existing methods (this article) and provide guidance for application-dependent use of the methods and recommendations for further methodological development (Berger et al. in Int J Life Cycle Assess,
2020
).
Methods
Starting in 2017, the task force developed a white paper, which served as its main input to a SETAC Pellston Workshop® in June 2018, in which a sub-group of the task force members developed recommendations for assessing impacts of mineral resource use in LCA. This article, based mainly on the white paper and pre-workshop discussions, presents a thorough review of 27 different life cycle impact assessment methods for mineral resource use in the “natural resources” area of protection. The methods are categorized according to their basic impact mechanisms, described and compared, and assessed against a comprehensive set of criteria.
Results and discussion
Four method categories have been identified and their underlying concepts are described based on existing literature: depletion methods, future efforts methods, thermodynamic accounting methods, and supply risk methods. While we consider depletion and future efforts methods more “traditional” life cycle impact assessment methods, thermodynamic accounting and supply risk methods are rather providing complementary information. Within each method category, differences between methods are discussed in detail, which allows for further sub-categorization and better understanding of what the methods actually assess.
Conclusions
We provide a thorough review of existing life cycle impact assessment methods addressing impacts of mineral resource use, covering a broad overview of basic impact mechanisms to a detailed discussion of method-specific modeling. This supports a better understanding of what the methods actually assess and highlights their strengths and limitations. Building on these insights, Berger et al. (Int J Life Cycle Assess,
2020
) provide recommendations for application-dependent use of the methods, along with recommendations for further methodological development.
•Analysis of the resource efficiency indicator: GDP/DMC.•A new indicator to measure resource efficiency is proposed.•This alternative indicator is based on the exergy analysis.•Application of the new ...indicator to the mineral balance in Spain.
This paper analyzes the drawbacks of using the lead indicator Gross Domestic Product divided by Domestic Material Consumption (GDP/DMC) proposed by the European Commission as part of the Resource Efficiency Roadmap. As an alternative, we propose to assess mineral resource efficiency through exergy replacement costs instead of using mass terms. Exergy replacement costs represent the useful energy that would be required to return minerals from the most dispersed state (the bedrock) to their original conditions (of composition and concentration in the mineral deposits). Dispersing a scarce mineral such as gold or oil has a much higher replacement cost than that of iron or limestone and in the final accounting, the first minerals have a greater weighting. Consequently, the tonnage produced and dispersion degree are considered in the proposed index. This new index would lead to more developed policies that could reduce the consumption of scarce materials with higher replacement costs. The suitability of the proposed indicator is evaluated through the case study of mineral balance in Spain.
PDF
