A chemical element sustainability index

As product development becomes increasingly complex, the demand for the earth's mineral ores increases and with it, the challenge to achieve global “sustainability”. Chemical elements are the building blocks of natural resources which are sourced from across the planet to manufacture globally traded goods. While global technological, social and economic progress accelerates, evaluating the sustainability of these building blocks remains a challenge. Numerous methodologies to evaluate sustainability exist but most rely on high levels of data collection. In this paper, a methodology is presented within a multi-criteria decision analysis and composite indicator framework with the aim of rapidly and comprehensively estimating the sustainability of a chemical element . The framework is based on triple bottom line principles; the environment, economy and society, to measure the sustainability of 59 chemical elements. The output, the chemical element sustainability index (CESI), is a single value supported by the aggregation of the Human Development Index, Global Warming Potential, and National Economic Importance indicators, derived through a rigorous and systematic selection process. Recycling rate is employed within the framework as a control variable given its importance as a sustainability strategy. The results show that the greater the Human Development Index, National Economic Importance and Recycling Rate, and the lower the Global Warming Potential, the more sustainable the chemical element is, and vice-versa. The CESI was validated using three representative piezoelectric materials as a case study. The framework presented is useful for product designers, policy makers and educational bodies, to support decision making towards sustainable production and consumption

Life cycle assessment and environmental profile evaluations of high volumetric efficiency capacitors

High volumetric efficiency capacitors are found in all smart electronic devices, providing important applications within circuits, including flexible filter options, power storage and sensing, decoupling and circuit smoothing functions. Multilayer ceramic capacitors (MLCCs) hold the major market share but tantalum electrolytic capacitors (TECs) provide a viable alternative if higher breakdown strengths are required. The reduced costs, smaller dimensions suitable for space-constrained electronic circuits, exceptional high-frequency characteristics, higher reliability, ripple control and longevity, however, are driving the market to replace TECs with MLCCs wherever possible. To date, no current research regarding the transition from TECS to MLCCs has been conducted from an entirely environmental viewpoint. This article identifies, quantifies, ranks and compares the environmental impacts of the MLCC and TEC supply chains using an integrated hybrid life cycle assessment framework. Three recovery methods: incineration; hydrometallurgy and pyrometallurgy are considered in the overall impact assessment. Electrical energy consumption during fabrication alongside the use of nickel paste are the major environmental hotspot for MLCCs. The high proportion of tantalum in TECs results in an overall greater environmental impact in comparison with MLCCs, due to intensive extraction, processing and purification requirements of tantalum. Of the three recovery methods, the hydrometallurgy process offers the least environmental impact for both MLCCs and TECs. Overall, the current work shows that while the industry led transition from TECs to MLCCs offers both an operational and functional edge, it is also an environmentally intelligent move. Intervention options that can further drive down the environmental impacts of MLCCs are also proposed such as a reduction in the reliance of MLCCs on rare earth elements and Cu external electrodes in some designs and material recovery

Environmental life cycle assessment and techno-economic analysis of triboelectric nanogenerators

As the world economy grows and industrialization of the developing countries increases, the demand for energy continues to rise. Triboelectric nanogenerators (TENGs) have been touted as having great potential for low-carbon, non-fossil fuel energy generation. Mechanical energies from, amongst others, body motion, vibration, wind and waves are captured and converted by TENGs to harvest electricity, thereby minimizing global fossil fuel consumption. However, only by ascertaining performance efficiency along with low material and manufacturing costs as well as a favorable environmental profile in comparison with other energy harvesting technologies, can the true potential of TENGs be established. This paper presents a detailed techno-economic lifecycle assessment of two representative examples of TENG modules, one with a high performance efficiency (Module A) and the other with a lower efficiency (Module B) both fabricated using low-cost materials. The results are discussed across a number of sustainability metrics in the context of other energy harvesting technologies, notably photovoltaics. Module A possesses a better environmental profile, lower cost of production, lower CO2 emissions and shorter energy payback period (EPBP) compared to Module B. However, the environmental profile of Module B is slightly degraded due to the higher content of acrylic in its architecture and higher electrical energy consumption during fabrication. The end of life scenario of acrylic is environmentally viable given its recyclability and reuse potential and it does not generate toxic gases that are harmful to humans and the environment during combustion processes due to its stability during exposure to ultraviolet radiation. Despite the adoption of a less optimum laboratory manufacturing route, TENG modules generally have a better environmental profile than commercialized Si based and organic solar cells, but Module B has a slightly higher energy payback period than PV technology based on perovskite-structured methyl ammonium lead iodide. Overall, we recommend that future research into TENGs should focus on improving system performance, material optimization and more importantly improving their lifespan to realize their full potential

Drivers of U.S. toxicological footprints trajectory 1998–2013

By exploiting data from the Toxic Release Inventory of the United States, we have established that the toxicological footprint (TF) increased by 3.3% (88.4 Mt) between 1998 and 1999 and decreased by 39% (1088.5 Mt) between 1999 and 2013. From 1999 to 2006, the decreasing TF was driven by improvements in emissions intensity (i.e. gains in production efficiency) through toxic chemical management options: cleaner production; end of pipe treatment; transfer for further waste management; and production scale. In particular, the mining sector reduced its TF through outsourcing processes. Between 2006 and 2009, decreasing TF was due to decrease in consumption volume triggered by economic recession. Since 2009, the economic recovery increased TF, overwhelming the influence of improved emissions intensity through population growth, consumption and production structures. Accordingly, attaining a less-toxic economy and environment will be influenced by a combination of gains in production efficiency through improvement in emissions mitigation technologies and changes in consumption patterns. Overall, the current analysis highlights the structural dynamics of toxic chemical release and would inform future formulation of effective mitigation standards and management protocols towards the detoxification of the environmen

The role of cycle life on the environmental impact of Li6.4La3Zr1.4Ta0.6O12 based solid-state batteries

This study compares the environmental impacts of a lithium‐ion battery (LiB), utilizing a lithium iron phosphate cathode, with a solid‐state battery (SSB) based on a Li6.4La3Zr1.4Ta0.6O12 garnet‐structured electrolyte. It uses a hybrid life cycle assessment (LCA), according to two functional units, delivery of 50 MJ of electrical energy and kg of battery, to expand the system boundary. The results of the process LCA indicate that the environmental impact of LiBs is lower than SSBs across most environmental impact categories. Conversely, the input–output upstream global warming potential (GWP) of the LiBs, calculated by hybrid LCA, is higher than that of the SSBs. Sensitivity analysis shows that the SSB cycle life must increase from 100 to 2800 to achieve a GWP impact lower than that of LiBs and therefore outperform LiBs in this environmental impact category. The study, therefore, demonstrates that research into SSBs must be accelerated to achieve a functional and safe battery technology with a reduced impact on the environment

Equitable global value chain and production network as a driver for enhanced sustainability in developing economies

Recent studies on the global value chain (GVC) have highlighted the need to better integrate the value chains of developing countries of the global South with that of the global North regions, which are more highly developed. This is aimed at enhancing the economic and social sustainable upgrading of the value chains of the global South regions. The paper thus seeks to answer a critical question as to whether the existing GVC set-up pertaining to global North and South countries is equitable and whether it would yield the needed socio-economic and wider sustainable benefits, particularly to global South countries. a conceptual Global Value Chain (GVC) model is developed based on the economy-wide and system-based Multi-Regional Input–Output methodology to achieve this goal. Subsequently, this was empirically tested to measure embodied flows in capital and labour for sustainable development between global North and South regions. These are achieved using the GVC networks of the UK (from the global North) and some countries in sub Saharan Africa (from the global South) to exemplify these developments. With implications for equitable, sustainable development, our study shows significant imbalances exist in the flows of value added activities from the global South to the global North, particularly in the primary industries, which produce low-value products in their raw state. Subsequently, this creates a disproportionate economic disadvantage for South countries. As such, if global South countries are to fully benefit from GVC, the study shows that these imbalances must be addressed, such as through structural changes in the economies of global South countries from their dependencies on the primary industries

A critical review of the impacts of COVID-19 on the global economy and ecosystems and opportunities for circular economy strategies

The World Health Organization declared COVID-19 a global pandemic on the 11th of March, 2020, but the world is still reeling from its aftermath. Originating from China, cases quickly spread across the globe, prompting the implementation of stringent measures by world governments in efforts to isolate cases and limit the transmission rate of the virus. These measures have however shattered the core sustaining pillars of the modern world economies as global trade and cooperation succumbed to nationalist focus and competition for scarce supplies. Against this backdrop, this paper presents a critical review of the catalogue of negative and positive impacts of the pandemic and proffers perspectives on how it can be leveraged to steer towards a better, more resilient low-carbon economy. The paper diagnosed the danger of relying on pandemic-driven benefits to achieving sustainable development goals and emphasizes a need for a decisive, fundamental structural change to the dynamics of how we live. It argues for a rethink of the present global economic growth model, shaped by a linear economy system and sustained by profiteering and energy-gulping manufacturing processes, in favour of a more sustainable model recalibrated on circular economy (CE) framework. Building on evidence in support of CE as a vehicle for balancing the complex equation of accomplishing profit with minimal environmental harms, the paper outlines concrete sector-specific recommendations on CE-related solutions as a catalyst for the global economic growth and development in a resilient post-COVID-19 world

Life cycle assessment of functional materials and devices : opportunities, challenges, and current and future trends

Functional ceramics such as piezoelectrics, thermoelectrics, magnetic materials, ionic conductors, and semiconductors are opening new frontiers that underpin numerous aspects of modern life. This widespread usage comes with a responsibility to understand what impact their mass production has on the environment. Life‐cycle assessment (LCA) is a tool employed for the identification of sustainable materials pathways through the consideration of environmental burdens of materials both during fabrication and as a final product. Although the LCA technique has been widely used for the evaluation of environmental impacts in numerous product supply chains, its application for environmental profiling of functional ceramics is now gaining attention. This paper presents a review of current developments in LCA, including existing and emerging applications with emphasis on the development and fabrication of functional materials and devices (FM&D). Selected published works on LCA of functional ceramics are discussed, highlighting the importance of adopting LCA at the design stage and/or at laboratory stage before expensive investments and resources are committed. Drawing from the extant literature, we show that the integration of environmental and sustainability principles into the overall process of FM&D manufacturing, in a way that anticipates foreseeable harmful consequences while identifying opportunities for improvement, can aid the timely communications of key findings to functional materials developers. This guides the orientation of research, development and deployment, and provides insights toward the prioritization of research activities while potentially averting unintended consequences. It is intended that the review presented will encourage the materials science community to engage with LCA to address important materials design, substitution, and optimization needs

Are lead-free piezoelectrics more environmentally friendly?

Considered as a less hazardous piezoelectric material, potassium sodium niobate (KNN) has been in the fore of the search for replacement of lead (Pb) zirconate titanate for piezoelectrics applications. Here, we challenge the environmental credentials of KNN due to the presence of ~60 wt% Nb2O5, a substance much less toxic to humans than Pb oxide, but whose mining and extraction cause significant environmental damage

Decarbonising ceramic manufacturing : a techno-economic analysis of energy efficient sintering technologies in the functional materials sector

The rising cost of energy and concerns about the environmental impact of manufacturing processes have necessitated the need for more efficient and sustainable manufacturing. The ceramic industry is an energy intensive industrial sector and consequently the potential to improve energy efficiency is huge, particularly through the introduction of modern sintering technologies. Although several energy efficient sintering processes have been developed, there is no comprehensive techno-economic analysis which compares and contrasts these techniques. This paper presents a critical review and analysis of a number of sintering techniques and compares them with the recently developed cold sintering process (CSP), including mode of operation, sintering mechanism, typical heating rates, duration of sintering, energy consumption profile and energy saving potential, limitations, key challenges for further development and current research efforts. By using a figure of merit, pounds per tonne of CO2 saved (£/tCO2-eq), which links initial capital investment with energy savings, within a framework derived from ranking principles such as marginal abatement cost curves and Pareto optimisation, we have demonstrated that under the scenarios considered for 3 separate functional oxides ZnO, PZT and BaTiO3, CSP is the most economically attractive sintering option, indicating lower capital costs and best return on investment as well as considerable energy and emission savings. Although the current work establishes the viability of CSP as a competitive and sustainable alternative to other sintering techniques, the transition from laboratory to industry of CSP will require hugely different facilities and instrumentation as well as relevant property/performance validation to realise its full potential