Material Recovery Rate Research Articles

Methodology and Database for the Quantification of the Technical Recyclability of Electrical and Electronical Equipment Demonstrated on a Smartphone Case Study

Assessing a given product’s design and its recyclability using mass flow analysis based on the material separation and recovery rates of individual recycling processes under realistic conditions can support design decisions promoting better recyclability. EN 45555 defines the calculation of the technical recyclability of electrical and electronic equipment (EEE). However, the lack of specific recycling rates for material or processes often leads to either too small or too high recyclability values. Herein, an extensive database of such recycling rates is presented. Moreover, the quality of recycling is considered. The typical classification into “recycled” and “lost” is expanded into four categories, namely “circular”, “recycled”, “alternate material recovery” and “lost”. The recycling rate database includes yields for all four categories and covers 30 materials for 14 recycling processes relevant in waste EEE (WEEE) treatment. These data enable a detailed calculation of the recyclability of various EEE for multiple recycling scenarios covering the entire WEEE recycling chain. Fraunhofer IZM performed an internal critical review of the data. The recycling rates database can act as a solid foundation for comparing the recyclability of various electronics in different scenarios and recyclability indices. For example, the recyclability of typical smartphones is investigated comparing different dismantling and recycling scenarios highlighting the potential of both database and methodology.

Modelling, analysis and forecasting of photovoltaic waste in Malaysia towards sustainable recycling by 2050

Malaysia is currently pushing for greater solar photovoltaic (PV) penetration through various policies, hence need to assess the consequent PV waste situation in preparation for sustainable End-of-Life (EoL) management of the PV systems. Through incorporation of fixed-loss, early-loss, and regular-loss scenarios into Malaysia's PV roadmap, it is projected that 229,009.17 tons to 481,137.12 tons of PV waste would be generated by 2050. Implementing current achievable PV material recovery rates would result in economic value creation between RM 1.02-2.21 billions (USD 213.78-463.92 millions) and carbon emissions avoidance between 398,858.41 tons CO2-eq to 785,712.93 tons CO2-eq by 2050. With crystalline silicon (c-Si) technology contributing more than 60% of waste share, 2029 to 2039 would be the suitable time period to jumpstart recycling operation due to consistent annual c-Si waste input of 8,000 tons/y for financially sustainable recycling. These findings can help garner support for sustainable EoL management of PV waste in Malaysia.

Sustainable and green removal of arsenic from crude tin via vacuum gasification–directional condensation

In the realm of high–tech industries, Sn has emerged as an indispensable strategic metal. However, the pyrometallurgical refining process of crude Sn is marred by the production of a substantial amount of hazardous solid waste, notably As–Al slag, posing a direct threat to the ecological safety of the production areas. This study delineates a novel process for the removal of As from crude Sn, employing vacuum gasification–directional condensation, corroborated by theoretical calculations and laboratory experimental research. Theoretically, at a system pressure ranging from 1–10 Pa, the initial volatilization temperatures of Sn and As exhibit significant variance. However, the formation of intermetallic compounds can induce Sn volatilization. Experimentally, the condensation temperature for As was predominantly within 331.7–484.7 K. During the vacuum gasification–directional condensation process, the presence of Sn4As3 intermetallic compounds impeded As volatilization. And under optimal conditions, the As content in the Sn product was recorded at 0.0053 %. Inspired from the calculations, a multistage vacuum distillation method was successfully proposed and achieved to remove As from crude tin. Typically, the total material recovery rate is 99.96 %, and the direct rate of Sn is 93.02 %. The total power consumption and emission of this process are better than the corresponding parameters of other treatment processes, which is a promising solution for the cleaning and effective removal of As.

A new method for simulation modelling of leaner remanufacturing in PaaS settings

The application of simulation technologies (STs) in the industry 4.0 paradigm can accelerate the implementation of the circular economy (CE) in companies by faster modeling and optimization of value retention processes (VRPs), such as remanufacturing or refurbishment. In business practices, the efficiency of the collection of used products and their recovery for a new or extended lifecycle is influenced by a high level of uncertainty. The product-as-a-service (PaaS) model might change the boundary conditions, which will decisively influence the operational factors such as time for a disassembly, and material recovery rate. The state-of-the-art in commercial simulation software (e.g., FlexSim, Simio, Arena) is based on the object-oriented approach, which requires that users must build the model themselves from a set of objects (object libraries), which is effective for a traditional linear process but is less suitable for multiple flow of a product between PaaS contracts. Remanufacturing in PaaS for consumer markets is currently a niche practice, due to the difficulties of providing its economic viability. Lean management practices are promising in lowering the cost of remanufacturing. The aim of this paper is to develop a new method for simulation modeling using a high-level script language, similar to those used by industry experts, according to lean remanufacturing principles under PaaS conditions. This novel method is built on the user-centric principle. Thus, it enables to build the simulation models and to use them by decision-makers in business practice who are not specialists in simulation modeling and do not have programming competences. The library of reference processes for remanufacturing in PaaS is defined with the industrial partners.

Recycling of Electronic Waste using Hydrometallurgical Techniques

This study investigates the correlation between electronic waste recycling, material recovery, and the consequent purity levels. It underscores the substantial influence of hydrometallurgical processes on the recycling process. Experiment 2, with an optimum chemical concentration, exhibited a 50% increase in metal recovery efficiency relative to Experiment 1. This illustrates the substantial improvement in material purity attained by hydrometallurgical experiments. The analysis of contaminant removal demonstrates a 40% enhancement in separation efficiency in Experiment 2, signifying the process’s efficacy. Experiment 3, which included further optimization of chemical parameters and modifications to process temperature, achieved a 30% decrease in recycling time, underscoring enhanced operational efficiency. Notwithstanding the elevated beginning expenses of chemical reagents, Experiment 2 achieved a 20% decrease in total recycling costs, underscoring the economic feasibility of the method. This highlights the need of meticulously controlling electronic trash to get elevated material recovery rates and cost-effectiveness. The findings elucidate the interplay between hydrometallurgical methods and electronic waste recycling, presenting ideas for enhancing recycling efficiency and environmental sustainability.

Circular Economy Implementation in Textile Industry using Design for Disassembly

The textile industry is a very resource-intensive sector, considerably contributing to environmental deterioration via substantial use of water, electricity, and chemicals. With the global transition towards sustainable practices, the notion of a circular economy has become more significant, focusing on prolonging product lifespans, reducing waste, and facilitating material recovery. An effective method for achieving circularity in the textile sector is Design for Disassembly (DfD), which facilitates the straightforward deconstruction of items for recycling or reuse. This study examines the use of Design for Disassembly (DfD) in textile production, emphasizing methods that enable the straightforward separation of fibers, trimmings, and fasteners, hence improving garment recyclability. Data was gathered via a comprehensive examination of textile product designs, production methodologies, and recycling methods throughout the sector. Findings demonstrate that the use of DfD may substantially decrease waste and enhance material recovery rates. Nonetheless, obstacles like redesign expenses, customer awareness, and compatibility with existing production techniques persist. This study presents a detailed technique for incorporating Design for Disassembly (DfD) into textile manufacturing and examines its possible effects on the circular economy. The results substantiate the assertion that the implementation of DfD may be a crucial advancement toward attaining sustainability in the textile sector.

Simulation-based life cycle assessment of secondary materials from recycling of lithium-ion batteries

The EU Battery Regulation is aimed at minimizing negative impact of waste batteries on the environment. Recycling of lithium-ion batteries is one way to reduce those impacts. However, a lack of detailed process-level data is limiting the environmental impact assessment. In this study, the necessary data is generated using process simulation, and is used to estimate the material recovery rates and environmental impacts of a recycling nickel-manganese-cobalt-based battery. We apply and allocate the impacts of recycling to determine secondary battery material carbon footprints. The results were compared with that of primary raw materials based on mass-based and economic value-based allocation. In reference scenario, applying economic value-based allocation resulted in cobalt sulphate and nickel sulphate having 73.5 % and 57.4 % lower carbon footprint than their primary, however, lithium carbonate had a 20.8 % higher footprint. The results indicate the need to improve material recoveries for meeting EU Battery Regulation targets, while minimizing environmental impact.

Towards a sustainable approach using mineral or carboxylic acid to recover lithium from lithium iron phosphate batteries

Lithium‑iron phosphate (LFP) batteries are commonly used in electric vehicles and stationary energy storage systems due to their high energy density, long cycle life, and safety. Processing of LiFePO4 batteries is difficult due to the complex battery chemistry and the lack of effective recycling options. The information currently available on recycling LFP batteries points to a low recycling efficiency and material recovery rate, which causes significant losses of valuable metals and environmental discharges of hazardous materials. Given the rising need for batteries and the detrimental environmental impact of their disposal, this is a critical concern. Therefore, it is essential to create effective and sustainable battery recycling methods in order to reduce waste and lower the impact on the environment. The goal of this publication is to outline a viable alternate strategy for recycling LFP batteries. Lowest acid concentrations are utilized in this method in order to enable the selective leaching of lithium. Both inorganic acids (e.g., H3PO4 and H2SO4) and organic alternatives (such as citric acid and oxalic acid) are tested at low concentrations (0.01–0.1 mol/l), in order to integrate sustainability aspects at this early stage of development and to directly compare the outcomes. Based on thermodynamic calculations, it was possible to recover lithium with a high efficiency (> 90%) using a subsequent precipitation sequence, thus returning this high-quality material to the raw material cycle with an appropriate morphology and purity.

Thermal degradation and performance evolution mechanism of fully recyclable 3D printed continuous fiber self-reinforced composites

An innovative recycling method that does not require separation of the reinforcement and matrix is been proposed based on 3D printing of continuous fiber self-reinforced composites. The continuous fiber self-reinforced polyphenylene sulfide (PPS) composites were mechanically ground and directly remanufactured by screw extrusion 3D printing. The recycling procedure was accelerated and the thermal processing of the material was reduced. This recycling paradigm of self-reinforced composites with in-situ resource utilization is ideally suited to the space environment. The recycled self-reinforced composites showed no significant loss in tensile properties and even exhibited a slight increase after multiple recycling cycles owing to the melted PPS fiber in comparison with original PPS matrix. Since recycled material didn't separate the fiber from the matrix, its flexural strength and modulus increased by 34.11% and 51.81%, respectively, when compared to original PPS matrix. Molecular structure, rheological changes, and crystallization behavior were systematically investigated to elaborate the thermal degradation mechanism of recycled composites. The results obtained from systematical characterizations indicated that the recycled composites formed the cross-linking structure when subjected to multiple screw extrusion processing. The energy consumption of the screw extrusion-based 3D printing method was also conducted. The total energy intensity of recycling and remanufacturing processes were only about 17.9 MJ/kg. Spatial suitability, considering the advantages of self-reinforced composite recycling for space applications, were analyzed. Finally, theoretical material recovery rate of 100% for self-reinforced composites opens the prospect to reduce maintenance logistics in space. A future application scenario for fully recyclable self-reinforced composites in space was explored.

Waste free construction site–A buzzword, nice to have or more

The building and construction industry is responsible for up to 25% of the total waste generated globally. Most construction sites in Norway on average generate 40–60 kg waste per gross floor area built and the average material recovery rate is ca. 46%. Existing requirements focus on waste sorting as a measure to increase material recovery rates. There are on-going national activities with an ambition to achieve waste free construction sites. However, there is lack of a common definition, standard and transparent data collection, and reporting system. This study presents a method for the evaluation and follow-up of construction waste and the associated greenhouse gas (GHG) emissions. The methodology was tested using the actual construction waste data collected from 36 Norwegian building cases to evaluate the quantity of construction waste, waste-related GHG emissions per building typology, sorting grade and waste recycling rate. The buildings in total generated ca. 7800 tonnes of waste and ca.12900 tonnes CO2eq and on average ca. 51 kg/m2 waste and 88kgCO2eq/m2. The building projects had a high average sorting grade (89%) and a low average recycling rate (32%). Gypsum, mixed wood, clean wood, and mixed waste are the top waste fractions representing ca. 56% of the total waste volume. This highlights there is still a long way to go to achieve waste free construction sites ambitions. The results also suggest the need for using transparent data collection and communication methods, collaboration in the value chain, stricter regulations, and incentives for encouraging the development of new and existing waste prevention solutions and technologies.

Sustainability performance evaluation of municipal selective collection systems applied to a case study

Despite the existence of several waste recycling initiatives in Brazil, the national average of recyclable material recovery rates still remains below 3%. In this context, it is necessary to diagnose the performance of systems to implement improvement actions, considering the particularities of each system. In this study, we describe the application of a method capable of diagnosing the effectiveness of selective collection systems by identifying a general sustainability index, calculated based on 16 performance indicators. The study focused on the city of Volta Redonda and was organized into three stages: identification of the performance evaluation method; data collection and calculation of indicators; and calculation of the sustainability index. The index value found for the city was 0.47, which represents an unfavorable level of sustainability. In this case, Volta Redonda is making insufficient investments in its selective waste collection system. The factors that contributed to this low index are: an outdated solid waste management plan, low collection coverage, low recovery rate of recyclable materials, high rejection rate, high selective collection cost, outdated cost of selective collection service, precarious occupational health and safety conditions of members of waste picker cooperatives, and lack of registration of residences for donation of recyclable materials.

Are there limits to robustness? Exploring tools from regenerative economics for a balanced transition towards a circular EU27

The first step for transforming the current linear and degenerative socio-economic systems into ones that are circular and regenerative is to understand how they grow and develop. Here, we explore whether there are limits to robustness of a socio-economic system as the result of a linear metabolic structure, and how those limits could theoretically be affected by its transition to a circular economy. First, we study how the circular use of materials and the economic openness of the EU27 would affect the value of its circularity rate (as defined by Eurostat), theoretically. Then, given that the circularity rate does not capture regenerative aspects, we develop a conceptual framework based on regenerative economics and on indicators from ascendency analysis and ecological network analysis. We use this framework to assess a theoretical future case where the EU27 manages to successfully transition to a CE within its given linear material flow metabolism. The results show that there are limits to robustness, and which do not necessarily correspond to a maximum circularity rate. None of the 45 scenarios assessed can theoretically lead to the maximum robustness observed in natural ecosystems, including those which maximized the circularity rate. Interestingly, the highest possible robustness value is obtained at a circularity rate of about 33% as a combination of a material recovery rate of 30% and of a material export rate of 10%. Scenarios of higher circularity rate (as the result of higher export rates and/or higher material recovery rates) seem to lead to brittle networks. Other indicators from regenerative economics are also discussed. Furthermore, the results show that even if substantial steps are taken by the EU27 towards a circular economy, 100% circularity rate seems to be unlikely. This analysis highlights that the use of tools from regenerative economics can assist policy makers and researchers to account for and to monitor network properties such as those of resilience and robustness, during strategic planning activities for a transition to a regenerative circular economy. • Linear socio-metabolic structures have limits to their robustness. • Achieving 100% circularity rate in EU27's material flow metabolism is unrealistic. • High material recovery and export rates increase the brittleness of linear networks. • Network structure conceptualization matters in regenerative economics. • Circularity transitions should be considered in tandem with regenerative economics.

Review of recycling waste plastics in asphalt paving materials

An ever-growing demand for depleted natural resources is one of the significant challenges facing the global asphalt pavement industry in building and maintaining global asphalt pavements. Because plastics are ubiquitous in the global economy, they are the latest in a series of high-profile materials to attract attention. Their low material recovery rates and the environmental impact of current disposal methods pose a threat to plastic recycling. Recycling plastic wastes in asphalt pavement is a possible approach to reducing environmental pressure and the demand for depleted natural resources. Many studies have proposed recycling plastic waste in asphalt pavement using dry- and wet-processed technologies. This review aims to comprehensively evaluate the feasibility of various recycled plastics in asphalt pavement concerning the properties of compatibility, storage stability, microstructure, thermo-rheology, and mechanical performance and to identify challenges and recommendations for the future. This review discusses recent developments and the feasibility of using plastic wastes as modifiers or additives to asphalt binders or asphalt mixtures in dry and wet processes, focusing on different materials from waste streams, how to produce such modified materials, and the characteristics of plastic waste modified asphalt, thus contributing to the sustainable management of resources and production of useful paving materials.

Prospective material and substance flow analysis of the end-of-life phase of crystalline silicon-based PV modules

The approaching end-of life phase of early installed PV modules gave rise to a variety of potential end-of-life strategies, ranging from basic generic waste management strategies to advanced case-specific recycling options. However, no comprehensive assessment on the full range of technological possibilities is available and only limited attention was given to the material recovery rates of these different technologies in light of circular economy. In addition, current material recovery rates are indifferent towards the material value and the value of their secondary applications. Based on an extensive literature review, ten end-of-life scenarios with potential learning effects are identified and their material flows are quantified using a combined material and substance flow analysis. Subsequently, material recovery rates from a mass, economic value and embodied energy perspective are calculated, incorporating the differences in secondary applications. The differences in the mass-based recovery rates of the seven end-of-life scenarios that did not have landfill or municipal waste incineration as the main destination were minimal, as 73-79% of the mass was recovered for the best-case learning scenario. For the economic value recovery rate (9-66%) and the embodied energy recovery rate (18-45%), more profound differences were found. The collection rate was identified as most crucial parameter for all end-of-life scenarios, learning scenarios and recycling indicators. The mass-based recovery rate might favor end-of-life scenarios that lead to dissipation of valuable materials in non-functional secondary applications. Additional targets are required to avoid cascading of valuable materials and to avoid the economic cost and environmental burden of virgin materials.

Dynamic modelling of Australian rooftop solar photovoltaic product stewardship transition

As rooftop solar photovoltaic (PV) adoption in Australia is exponentially growing in the past decade, there is a need to promote effective product stewardship for PV panels reaching their end-of-life (EoL). This paper presents the development of a System Dynamics (SD) model for managing EoL rooftop PV panels based on the circular economy concept. Four stages of the SD modelling process include problem scoping and variable identification, model conceptualisation, SD model development, and scenario analysis. Stakeholder engagement is central to this research as the system under study is underpinned by high uncertainties and limited data availability. Four socio-technical transition pathways examined in this study include market-driven growth, conservative development, shared responsibility, and disruptive change. The simulation results indicated an improvement of collection and recovery performance when a stringent product stewardship scheme is enabled and improvement of installers’ participation in the collection program. This study argued that a system of shared responsibility will be capable of balancing techno-economic motivations of stakeholders across the supply chain to participate in the recovery scheme, while being less disruptive to PV adoption. Under this scenario, a gradual change in regulatory requirements (e.g. recovery target and material recovery rate requirements) is introduced to allow a period of industry and market development.

Resource efficiency improvement: zero waste discharge planning in a pulp-and-paper firm under uncertainties

PurposeThis study develops an integrated zero waste discharge planning approach for improving resource efficiency in a pulp-and-paper manufacturing firm.Design/methodology/approachThe objectives of this study are to (1) identify the environmental, technical and social metrics in resource efficiency; (2) utilize fuzzy multi-objective programming and the hybrid particle swarm optimization algorithm to solve the fuzzy problem; and (3) develop an assessment for resource efficiency improvement in an industrial case study.FindingsThe findings demonstrate the superiority of hybrid particle swarm optimization algorithm in generating optimal results for a pulp-and-paper manufacturing firm.Practical implicationsThe findings demonstrate the superiority of hybrid particle swarm optimization algorithm in generating optimal results for a pulp-and-paper manufacturing firm.Originality/valueResource efficiency is a multi-objective problem in an uncertain environment. In particular, zero waste discharge planning involves minimizing the total cost and maximizing the waste material recovery rate, wastewater reuse, and waste heat recovery.

Multi-Stage Cold Forging Process for Manufacturing a High-Strength One-Body Input Shaft.

A multi-stage cold forging process was developed and complemented with finite element analysis (FEA) to manufacture a high-strength one-body input shaft with a long length body and no separate parts. FEA showed that the one-body input shaft was manufactured without any defects or fractures. Experiments, such as tensile, hardness, torsion, and fatigue tests, and microstructural characterization, were performed to compare the properties of the input shaft produced by the proposed method with those produced using the machining process. The ultimate tensile strength showed a 50% increase and the torque showed a 100 Nm increase, confirming that the input shaft manufactured using the proposed process is superior to that processed using the machining process. Thus, this study provides a proof-of-concept for the design and development of a multi-stage cold forging process to manufacture a one-body input shaft with improved mechanical properties and material recovery rate.

Scheme selection of design for disassembly (DFD) based on sustainability: A novel hybrid of interval 2-tuple linguistic intuitionistic fuzzy numbers and regret theory

Design for disassembly (DFD) is an essential design technique to consider the disassembly and recyclability of a product at the initial design stage. An efficient DFD technique provides the disassembling and recycling easily. However, the recent trends of disassembling and recycling are to consider the aspects of environmental and social sustainability. Due to shortage of energy and deterioration of the ecological environment, the sustainable production is an active research topic to use the economic and social benefits as the evaluation standard of a design scheme as well as its environmental characteristics. This paper provides a new approach for DFD based on sustainability. In this regard, a hybrid multi-attribute decision making (MADM) method integrating the regret theory (RT) and the entropy weighting method is firstly developed. To implement the proposed approach, an eight-criterion evaluation system of schemes based on sustainability including the factors of disassembly energy consumption, disassembly accessibility, fastener ratio, toxic material proportion, material recovery rate, disassembly expense, production and use noise, and waste emissions, is established. To better describe the fuzziness of human thinking and to avoid information loss/distortion during information aggregation phases, the evaluation information given by experts is presented by our proposed interval 2-tuple linguistic intuitionistic fuzzy numbers (I2LIFNs). The weight vector of index structure is determined by the entropy weighting method under the fuzzy environment. The RT is employed to get the final order of alternatives by considering and quantitating both the risk attitude and the regret attitude of experts. To show the applicability of this study, a case study including four kinds of refrigerator schemes, is conducted to validate the proposed method. An extensive comparison with other recent and state of the art methods along with a sensitivity analysis of 13 experiments, is executed to verify effectiveness and reliability of the proposed I2LI-RT method. Finally, the experimental results show that: 1) disassembly accessibility (C2), fastener ratio (C3), waste emissions (C8) and disassembly energy consumption (C1) have a large impact on the scheme selection of DFD based on sustainability as those attributes carry relatively the larger weights; 2) our proposed method outperforms other recent and state of the art methods and 3) the chosen scheme A1 is the winner in the majority of the sensitivity analysis cases (10 out of 13). At last but not least, the main finding is to furnish a systematic and efficient decision support tool for sustainable performance evaluation of product schemes of DFD.

Systems approach to end-of-life management of residential photovoltaic panels and battery energy storage system in Australia

Understanding the complexities around managing the end-of-life (EoL) residential solar photovoltaic (PV) and battery energy storage systems (BESS) is a precursor to a better decision-making process that mitigates unintended product life-cycle impacts. In this paper, a participatory Systems Thinking approach was utilised to build a causal loop diagram (CLD) for this system based on the collective knowledge of stakeholders. The developed CLD was categorised into three sub-systems: (1) waste flows; (2) regulatory aspects; and (3) industry strategies and government incentives. Two main system archetypes were identified in a reflection to the CLD, namely fixes that fail and drifting goals. The identified feedback loops indicate the need to introduce a comprehensive national product stewardship scheme, complimentary landfill restrictions, and provide sufficient incentives to industries for promoting recovery activities within residential PV panels and BESS sectors. An effective waste management system for these renewable energy technologies is most effective if industries are required to participate through regulation which also specifies certain targets, such as product and material recovery rates and establishes a sustainable funding model to meet operational requirements and future needs. The increasingly prohibitive overseas waste export market will require local industries and governments to collaboratively improve domestic recycling capability and capacity. In this light, the failure to build an effective EoL management system for residential PV and BESS will result in valuable and hazardous materials in both technologies to be disposed of in the landfill, stockpiled or illegally dumped; consequently, reinforcing unintended and adverse environmental impacts.

Legislation-induced planning of waste processing infrastructure: A case study of the Czech Republic

Trends in the treatment of municipal solid waste are changing worldwide. In the European Union, one of the largest economies in the world, the waste treatment and management among the member states vary significantly. To support and promote environmentally friendly waste management, the European Union issued directives commonly called the Circular Economy Package. This legislative is designed to accelerate the transition to a cleaner future. It gives an obligation to member states to meet specific landfilling and recycling targets. To reach these ambitious goals will be a challenging task, especially for the member states with less developed waste management systems. An approach using multi-stage stochastic programming is suggested for solving such a problem. The developed model considers current material recovery rates and trends in municipal waste, while uncertain waste production is forecasted by possible scenarios. The model enables sequential decision-making and assessment of various strategies for different future scenarios with specific years, locations, technologies and capacities for the establishment of the waste processing infrastructure. The utilization of the model and its computational tractability is demonstrated in a case study of the Czech Republic.