Shredder Residue Research Articles

Upgrading Mixed Plastic Waste through Industrial Symbiosis: Pseudoductile Regenerated Cellulose Fiber-Reinforced Shredder Residue Composites

Upgrading Mixed Plastic Waste through Industrial Symbiosis: Pseudoductile Regenerated Cellulose Fiber-Reinforced Shredder Residue Composites

Advancing Circular Economy through Knowledge Transfer: A Decade of Research Insights

Economic growth and sustainable development are central themes of the Sustainable Development Goals (SDGs) set by the United Nations and adopted by the European Commission for EU member countries. Transitioning to a circular economy (CE) aligns with the SDGs, particularly through the principles of reduce, reuse, and recycle (3Rs). This comparative analysis synthesises the contributions of multiple scholars, providing a cohesive understanding of current advancements and challenges in CE and sustainable resource management. Key themes include stakeholder collaboration, technological innovations, waste management, and policy frameworks. Effective waste management and valorisation of materials are highlighted, with significant advancements in electronic waste treatment, automotive shredder residue processing, and construction waste recycling. Moreover, the study emphasises the importance of cooperation through partnerships, as outlined in SDG17, and knowledge transfer in building trust within developed countries. The literature review reveals interactions between knowledge transfer components, such as research and development, foreign direct investment, and CE indicators, including circular material use rate and recycling rate. A bibliometric technique and VOSviewer were employed for visually representative and comprehensible literature analysis. The findings suggest that the integrated efforts of various stakeholders, technological advancements, and robust policy frameworks are essential for achieving a sustainable and circular future. By analysing these components, the research aims to evaluate the potential of EU member states to achieve sustainable development, providing valuable insights into the theoretical approaches and indicators used in CE and knowledge transfer studies.

Unveiling The Potential of Microwave Plasma Treated Char For Sustainable Automotive Shredder Residue (ASR) Management and Reduced Ecological Risk Of Cadmium

Introduction: This study explores the effectiveness of microwave plasma pyrolysis in reducing heavy metal concentrations, specifically cadmium, in automobile shredder residue (ASR). METHOD: The ASR was subjected to plasma pyrolysis at microwave power levels ranging from 800 to 1000W, resulting in a significant decrease in heavy metal concentration in the char. Utilizing the Bureau Communautaire de Référence (BCR) sequential extraction method, a standardized procedure developed by the European Commission, we assessed the chemical speciation and matrix properties of the char. The results indicated that microwave plasma treatment effectively decreased the bioavailable forms of cadmium. After 6 minutes of pyrolysis at 1000W, the exchangeable and acid-soluble fractions (F1) dropped to 10%, while the reducible fraction (F2) fell to 12%. RESULT: This treatment resulted in a substantial increase in the oxidizable (F3) and residue (F4) fractions, which reached 27% and 51%, respectively. Importantly, the potential ecological risk of cadmium decreased significantly, with the risk index (Er) dropping from 164.91 to 28.45, aligning with Taiwan's regulatory standards for non-hazardous waste.CONCLUSION: These findings suggest that microwave plasma pyrolysis is a promising and sustainable approach for the disposal of ASR, offering an environmentally friendly alternative for waste management. This study provides valuable insights for policymakers, environmental scientists, and industries seeking effective solutions for ASR treatment.

Valorization of Biomass and Industrial Wastes as Alternative Fuels for Sustainable Cement Production

The cement industry contributes around 7% of global anthropogenic carbon dioxide emissions, mainly from the combustion of fuels and limestone decomposition during clinker production. Using alternative fuels derived from wastes is a key strategy to reduce these emissions. However, alternative fuels vary in composition and heating value, so selecting appropriate ones is crucial to maintain clinker quality and manufacturing processes while minimizing environmental impact. This study evaluated various biomass and industrial wastes as potential alternative fuels, characterizing them based on proximate analysis, elemental and oxide composition, lower heating value, and bulk density. Sawdust, pecan nutshell, industrial hose waste, and plastic waste emerged as viable options as they met the suggested thresholds for heating value, chloride, moisture, and ash content. Industrial hose waste and plastic waste were most favorable with the highest heating values while meeting all the criteria. Conversely, wind blade waste, tire-derived fuel, and automotive shredder residue did not meet all the recommended criteria. Therefore, blending them with alternative and fossil fuels is necessary to preserve clinker quality and facilitate combustion. The findings of this research will serve as the basis for developing a computational model to optimize the blending of alternative fuels with fossil fuels for cement production.

Immiscible Polymer Blends Made from Industrial Shredder Residue Mixed Plastic with and without Melt Blending.

The processing of an immiscible polymer blend using melt blending (i.e., extrusion) often results in a polymer material with inferior mechanical performance compared with its virgin counterparts. Here, we report and compare the properties of immiscible polymer blends produced from industrial mixed plastic waste from shredder residue comprising at least four different polymers (acrylonitrile butadiene styrene, polystyrene, polypropylene, and polyethylene) with and without a prior melt-blending step employed. As anticipated, mixed plastic blend produced with a prior melt-blending step exhibited a more homogeneous microstructure, resulting in brittleness, poor work of fracture, and single-edge notched fracture toughness with a flat R-curve. Without the intimate polymers mixing arising from melt blending, the resulting mixed plastic blend was found to possess a more heterogeneous concentric ellipsoid microstructure with large single polymer domains. This mixed plastic blend demonstrated progressive failure under uniaxial tensile loading, along with a more ductile single-edge notched fracture toughness response accompanied by a growing R-curve. Digital image correlation and fractographic analysis revealed that melt blending created a large number of incompatible polymer boundaries that acted as stress concentration points, leading to brittleness and earlier onset catastrophic failure. The more heterogeneous mixed plastic blend produced without using a prior melt-blending step contains a smaller number of incompatible polymer boundaries. Additionally, the presence of larger single polymer domains also implies that the mechanical characteristics of the single polymer can be exploited in the immiscible mixed plastic blend. Our work opens up a simple pathway to add value to mixed plastic waste from shredder residue for use in engineering applications, diverting them away from landfill or incineration.

Study of chlorine removal from shredder residue: Thermal dechlorination and water leaching

Shredder residue (SR) is an inevitable waste in the production of steel by scrap melting, and the presence of chlorine is the main responsible for its non-use of energy. This study aimed to remove chlorine from SR by thermal dechlorination and water leaching. Thermal dechlorination was first studied from a PVC sample to evaluate the optimum parameters of temperature, heating rate, residence time and atmosphere (N2 or steam). Under optimal conditions for PVC dechlorination, chlorine removals of 73.7 (N2) and 68.0% (steam) were achieved. Optimal parameters were applied to thermal dechlorination of a Brazilian SR with a chlorine content of 2.12 wt%. Reductions in chlorine content to 0.95 and 0.51 wt% were observed with N2 and steam atmospheres, respectively. In an additional evaluation (conducted also with the Brazilian SR and in order to investigate the reactor rotation effect), it was observed that the reactor rotation does not influence the release of chlorine during the thermal treatment but modifies the granulometry of the produced solid. Samples obtained from this test were subjected to a water leaching study to further reduce the chlorine content. The parameters studied were the type of water (tap and distilled), granulometry and carbonation (contact with CO2) in a total of five washing cycles. Carbonation and use of distilled water achieved the highest chlorine removal resulting in a reduction of chlorine content from 1.13 to 0.45 wt%. The obtained results show directions for chlorine removal aiming at the energetic use of shredder residue.

Study on the pyrolysis characteristics and char gasification kinetics of pre-separated automobile shredder residues

Automobile shredder residue (ASR) is a typical solid waste produced by the end-of-life automobile industry. The pyrolysis and gasification of ASR are effective methods to achieve reduction and resource utilization. By means of thermogravimetric analysis and fixed-bed experiments, the distribution as well as physicochemical properties of five typical ASR pyrolysis products after pre-sorting were systematically investigated, and the gasification kinetics of their pyrolysis char under CO2 as well as steam were also studied. Results showed that the pyrolysis of ASR was basically completed at 500°C, and the pyrolysis gas yield increased significantly with temperature. The tar contained mainly poly-benzene rings with carbon atoms C11–15 and their derivatives. At high temperatures, the structure of pyrolysis char tended to become more ordered, with small functional group such as - OH, - NH, - CH3, - CC -, and - COOH fracturing. The residual amounts of heavy metals such as Cr, Pb, and Ni in pyrolysis char were mostly exceed 45%, which were significantly affected by the type of heavy metals, pyrolysis temperature and material type. Hydrogen production from steam gasification accounted for up to 65%, and the gasification reactivity was better than that of CO2 gasification. The activation energy (E) calculated through shrinking core model (SCM) and random pore model (RPM) was 38.81–105.44 kJ/mol and 39.53–98.56 kJ/mol, respectively, which provided a good fit to the gasification kinetics in two gasification atmospheres. This study provides detailed data for the ASR pyrolysis and gasification technology, which is an important reference value for ASR research.

Is the assimilation to a solid recovered fuel a viable solution for automobile shredder residues’ management?

Directive 2000/53/EC and the European Circular Economy Package (2018) required the Member States to take all the necessary measures to reach the reuse-recycling goal of 85% for end-of-life vehicles (ELVs). In 2019, Europe achieved 89.6% of reuse-recycling, but most EC countries are still not completely compliant, Italy standing, for example, at only 84.2%. For this reason, actions are necessary to increase reuse-recycling for the waste generated in the operations of ELV shredding and separation, known as automobile shredded residues (ASRs). This study was aimed at assessing if the assimilation of ASRs to a solid recovered fuel (SRF) was a feasible solution. That would allow the waste to lose its status (end-of-waste, EoW), thus increasing the recycling rate. The assimilation of ASRs to SRFs requires the compliance with a series of parameters, namely net calorific value (NCV), content of chlorine (Cl), mercury (Hg) and selected heavy metals. The above-mentioned parameters were analyzed in the principal ASR fractions, namely textile, plastic and foam rubber, found in the samples collected during four sampling campaigns (2017–2021) performed at the same ELV treatment plant. Notwithstanding the great variability observed in the four samples, the results of the analyses revealed that the three fractions were compliant with NCV, Cl and Hg content. Conversely, the heavy metals' content was found a more critical parameter, in fact only the plastic fraction was suitable for SRF assimilation. Textiles presented criticality for the content of copper (Cu), nickel (Ni) and antimony (Sb). The heavy metals' contamination of foam rubber was found to be strongly related to particles' dimensions. A model which put particle size and metals’ content into relationship was developed and validated. Removing particles of <40 mm significantly improved the quality of the material, however the content of Cu and Ni remained a critical issue for particles up to 200 mm. The SRF assimilation of the plastic fraction would increase the reuse-recycling rate of approx. 2.4–3.3%, thus allowing the achievement of the EC goals concerning the ELV management.

Evolution and speciation transformation of chlorine during automobile shredder residue pyrolysis

Disposal of automobile shredder residue (ASR) via pyrolysis enables the recovery of valuable products; however, the production of hazardous pollutants and low-value products is inevitable due to its high chlorine content. In this work, chlorine evolution behavior and the conversion mechanism during ASR pyrolysis between 480 and 600 °C were systematically studied. The experimental results for organic chlorine (Org-Cl) showed that released chlorinated gases were complex, and HCl only accounted for 35% of the gas phase products, while short-chain hydrocarbons with carbon atoms between two and four accounted for 52%. Chlorine was predominantly retained in the char, and Org-Cl was the primary contributor to the residual chlorine, accounting for over 50% of the char. The content of inorganic chlorine (InO-Cl) was low in the raw sample but significantly increased in the char. Through the distinction between organic and inorganic chlorine content in char, it was confirmed that Org-Cl could be converted to InO-Cl due to complex secondary reactions with metallic compounds. The conversion was favored by increasing the Org-Cl content and the temperature. Our findings clarified the evolution mechanism of chlorine and the transformation from Org-Cl to InO-Cl, thus providing guidance for chlorine regulation and the efficient recycling of metal resources.

Practical application of circularity micro-indicators to automotive plastic parts in an industrial context

The increasing amount of plastics in new vehicles, and the consequent growth of plastics in the automotive shredder residue, makes it imperative and urgent to improve reuse and/or recovery of plastics at the vehicle's end-of-life. Circularity micro-indicators can identify improvement guidelines and monitor the transition to a more circular economic model; however, the complexity, variety of scope and approach, and scarcity of information on most of the circularity micro-indicators hamper their practical adoption by companies.In this paper, we identify relevant micro-indicators for the automotive sector, focusing on key aspects for automotive plastic parts. Further, to showcase the application of these micro-indicators in a real industrial context, a case-study plastic automotive component was identified in collaboration with a tier II supplier and five complementary circularity micro-indicators were evaluated.We found 23 circularity micro-indicators (at the product level) that are highly relevant for automotive parts and we discuss individually how each can provide useful information. Results indicate an enormous improvement opportunity to improve circularity of plastic automotive parts, namely in the use of more sustainable material sources (recycled, bio-based, or compostable materials) and promotion of end-of-life recovery approaches (reuse or refurbish, and take-back systems).We concluded that practices adopted by industry to optimize production, in terms of design for manufacturing and design for assembly, as well as in the composition of plastic automotive parts, namely integral design, multi-material parts, or welding components made from different materials, severely limit the implementation of circular economy approaches, a situation that needs to be reverted by legislators and companies.

Enhancing pyrolysis of automobile shredder residue through torrefaction: Impact on heavy components formation in oil

Torrefaction of biomass is a well-known pretreatment method that can remarkably influence evolution of property of pyrolytic products in subsequent pyrolysis. Automobile shredder residue (ASR) is an important product in car recycling and it needs to be pretreated before recycling via pyrolysis. Nevertheless, how torrefaction impacts the composition and pyrolysis behaviours of ASR is still unknown, as ASR has a distinct composition from biomass. Thus, this study investigates the effect of torrefaction on the formation of heavy components in pyrolysis oil. ASR samples were torrefied from 240 °C to 330 °C and subsequently pyrolyzed from 600 °C to 800 °C with varied heating rates (ca. 80 °C /s and 0.17 °C /s). Results indicate that compared to raw ASR pyrolysis oil, torrefaction enhances the interaction between the volatile and semi-char, promoting the polymerization to form precursors of heavy components, thus the relative content of heavy components increases by >50% and heavy components containing heteroatoms decrease by >30% in the torrefied ASR pyrolysis oil, with the release of volatile heteroatom-containing compounds during torrefaction. More aliphatic heavy components are generated, reducing the overall aromaticity and degree of unsaturation of heavy components in the pyrolysis oil.

Impact of landfill characteristics on the atmospheric exposure to halogenated flame retardants in gulls

Large amounts of consumer products containing halogenated flame retardants (HFRs) are disposed of annually in landfills, which may lead to significant releases of these semi-volatile contaminants into the environment. During their foraging activities in landfills, gulls can be exposed to elevated levels of HFRs in air. Ring-billed gulls (Larus delawarensis) breeding in the densely populated Montreal area (QC, Canada) are significantly exposed to air levels of polybrominated diphenyl ethers (PBDEs) in or in the vicinity of landfills. However, no information is currently available on the specific characteristics of these landfills that can modulate the atmospheric exposure of ring-billed gulls to HFRs. The objective of this study was to investigate how atmospheric exposure in ring-billed gulls to PBDEs and other HFRs is influenced by selected landfill characteristics (i.e., daily cover materials, waste types and tonnage). Miniature passive air samplers (PASs) combined with GPS dataloggers were deployed for ten days during six years on the back of wild-caught ring-billed gulls breeding in the Montreal area. Atmospheric levels of several PBDEs and other HFRs determined in PASs were found to increase with the presence probability of gulls in the two largest landfills using automotive shredder residues as daily cover material. Weather variables including relative humidity and wind speed had a weak influence on atmospheric levels of HFRs in the bird-borne PASs. Our results suggest that automotive shredder residues represent a significant emission source of HFRs into the air of landfills, thus influencing atmospheric exposure of gulls and other birds foraging in these sites.

Hard carbons from automotive shredder residue (ASR) as potential anode active material for sodium ion battery

Graphite, the most prominent anode material for Li-ion battery, exhibited very poor performance in sodium ion battery. The electrochemical intercalation of Na+ ions in graphite is impeded due to smaller interlayer spacing. Here, we have reported ASR derived hard carbon as a suitable anode electroactive material for Na-ion battery. Prepared via single step selective thermal transformation, the hard carbons contain defects, heteroatoms, nanopore, and ordered carbon zones with expanded interlayer spacing. Among all the hard carbons, the hard carbon synthesised at 1100 °C, showed better electrochemical performance owing to its improved structural and morphological properties. The electrochemical study reveals that hard carbon synthesised at 1100 °C provides initial reversible capacity of 434mAh/g at a current density of 10 mA/g with a capacity retention of 53% after 100 cycles. Issues like global warming and climate changes have made human to shift their energy choices from fossil fuels to renewable sources. Although Li-ion battery is currently dominating the energy market, yet it falls short to meet the growing large scale energy storage system (EES) demand. Na-ion battery is considered as a worthy contender for growing ESS. The hard carbon studied in this work, can be a potential candidate for use as anode active material in Na-ion battery.

Pyrolysis of Automotive Shredder Residue (ASR): Thermogravimetry, In-Situ Synchrotron IR and Gas-Phase IR of Polymeric Components.

This article reports the characterisation of pyrolysis of automotive shredder residue using in situ synchrotron IR, gas-phase IR, and thermal analyses to explore if the automotive shredder residue can be converted into value-added products. When heating to ~600 °C at different heating rates, thermal analyses suggested one- to two-stage pyrolysis. Transformations in the first stage, at lower temperatures, were attributed to the degradation of carbonyl, hydroxyl, or carboxyl functional stabilisers (aldehyde and ether impurities, additives, and stabilisers in the ASR). The second stage transformations, at higher temperatures, were attributed to the thermal degradation of the polymer char. Simultaneous thermal analyses and gas-phase IR spectroscopy confirmed the evolution of the gases (alkanes (CH4), CO2, and moisture). The synchrotron IR data have demonstrated that a high heating rate (such as 150 °C/min) results in an incomplete conversion of ASRs unless sufficient time is provided. The thermogravimetry data fit the linearised multistage kinetic model at different heating rates. The activation energy of reactions varied between 24.98 and 124.94 kJ/mol, indicating a surface-controlled reaction exhibiting high activation energy during the initial stages and a diffusion and mass transfer control showing lower activation energy at the final stages. The corresponding frequency factors were in the range of 3.34 × 1013-5.68 × 101 mg-1/min for different pyrolysis stages. The evolution of the functional groups decreased with an increase in the heating rate.

Degradation Kinetics of Automotive Shredder Residue and Waste Automotive Glass for SiC Synthesis: An Energy-Efficient Approach

Generally, fossil carbon materials (coal, coke/char, and petroleum coke), biological carbon materials (charcoal, woodchips), and quartz from the earth’s crust are sources of carbon and silica to synthesise silicon carbide (SiC) at temperatures between 2000 and 2200 °C. The study investigated the isothermal and non-isothermal kinetics of synthesising SiC from automotive shredder residues (ASR) and windshield glass of end-of-life-vehicle (ELVs) at 1300 °C, 1400 °C, and 1500 °C for 30 min. The kinetics of ASR and waste glass degradation were studied by relating the thermogravimetric data via the Coats–Redfern model. The reaction mechanism includes the rapid formation of a gaseous SiO intermediate, and carbon reduction of the SiO to SiC is reaction-rate-controlling. The understanding of kinetics inferred that the optimisation of SiC formation is entirely associated with the conversion of SiO2 to SiO vapour and their reaction with CO and carbon particles. The kinetic parameters of the degradation of mixed ASR and waste glass were determined, and the activation energy of mixed ASR and glass for non-isothermal conditions are 22.48 kJ mol−1, 2.97 kJ mol−1, and 6.5 kJ mol−1, and for the isothermal study to produce SiC is 225.9 kJ mol−1, respectively. The results confirmed that this facile way of synthesising SiC would conserve about 50% of chemical energy compared to the traditional way of producing SiC. A beneficial route of transforming the heterogenous ASR and glass wastes into SiC with economic and environmental benefits is recognised.

Processing of automotive shredder residues: Economic evaluation of a process for energy and high-value metals recovery

Challenges in recycling heterogeneous waste remain untapped. Automotive shredder residue is one such heterogenous waste generated after processing End-of-Life Vehicles, making it difficult to process. There are two impediments to the recycling of ASR. One is the heterogeneity of the ASR (as received), and the other is not knowing what constituents to be extracted from the ASR. The ability of the thermochemical process to transform waste into beneficial products is well known. The objective of this work is based on a techno-economic evaluation of the recovery of energy and high-value metals from Automotive Shredder Residue. The equipment sizing and fabrication cost of each piece used in this process are calculated based on laboratory experiments. An integrated techno-economic study for processing heterogeneous waste ASR has not been studied in the literature previously. The economic evaluation was carried out assuming a plant life of 25 years. In addition, the plant's revenue was generated by the obtained products, and the payback period for energy and metal recovery was found to be 3 years respectively. The capital cost and operating cost for the ASR recycling plant with a combined approach of recovering energy and metals have been estimated from grass root stage. The outcome of this study confirms that ASR recycling has potential value for secondary resources and the process is economically viable. The resource recovery from ASR is an environmentally friendly technology where the maximum utilization rate is raised, along with energy saving and environmental protection by reduction of ASR waste in landfill.

Hydrogen production and pollutants emission characteristics by co-gasified of paper-mill sludge and automobile shredder residues in a commercial scale fluidized bed gasifier

This research investigated the hydrogen production and energy conversion from automobile shredder residues (ASRs) and paper mill sludge (PMS) co-gasified in a full-scale fluidized bed gasification plant. The results obtained from full-scale tests provided important information on the feasible assessment of ASRs-to-energy and the selection of alternative technologies for ASRs. Based on the analysis results of produced gas composition, H2, CO, and CH4 composition produced from paper-mill sludge gasified were 4.17%–6.01%, 3.08%–4.32%, 1.71%–2.4%, respectively. Another C2 gas composition ranged from 2.9% to 3.59%. The heating value of produced gas ranged between 1.64 MJ/Nm3 and 2.18 MJ/Nm3. In the case of 10% ASR addition, the heating value of produced gas was slightly increased to 1.84 MJ/Nm3-2.34 MJ/Nm3. The dioxin emission concentration of flue gas was approximately 0.064 ng I-TEQ/Nm3. It can comply with Taiwan regulation thresholds. The dioxin leaching concentrations of residues derived from gasification were also in compliance with regulation limits by the TCLP test. Meanwhile, in the case of 10% ASRs addition, the dioxin equivalence concentration of gasified residue was nearly 0.002 ng I-TEQ/Nm3. It was far below the current regulation standard limit. In summary, the results of this research have proved the performance of ASRs-to-energy by co-gasified with paper mill sludge using a full-scale gasification plant. The results obtained from this research also provided the information for selecting ASRs alternative technologies and operating full-scale gasifiers in the future.

Material Recycling for Manufacturing Aggregates Using Melting Slag of Automobile Shredder Residues

The quantity of waste from end-of-life vehicles is increasing with an increase in the number of scrapped internal combustion engine vehicles owing to international trends such as carbon neutrality and particulate matter reduction. The recycling rate must be ≥95%; however, the average recycling rate remains at approximately 89%. Therefore, the improvement of the recycling of automobile shredder residues (ASR) is gaining attention. In this study, four types of products (interlocking, clay, and lightweight swelled ceramic (LSC) bricks, and asphalt paving aggregate (APA)) were manufactured using ASR melting slag (ASRMS). Environmental performance, quality standards, and technology were evaluated to assess the recyclability of the manufactured bricks. The interlocking brick substituted melting slag for sand and stone powder as an aggregate. As melting slag content increased, absorption decreased and bending strength increased. Clay brick was manufactured by replacing kaolin and feldspar with melting slag that substituted for 20%. The quality of clay bricks mixed with over 15% melting slag was not better than standard. Asphalt paving aggregate was used to investigate the optimum condition of slag content in mixed asphalt; the mixture ratio showed that 61% broken stone of 13 mm, 6% screenings, 10% melting slag, 15% sand and 8% filler was most effective. A lightweight swelled ceramic brick was manufactured by using melting slag, front glass, and so on. Specific gravity and compressive strength ranged from 0.38 to 0.51 and from 339.7 to 373.6 N/cm2. ASRMS exhibited an environmental performance suitable for recycling and the manufactured bricks satisfied the quality standards. The recyclability of ASR was also assessed in terms of waste usage, conformance to quality standards, market size, and demand prediction. APA showed the best results followed by interlocking, clay, and LSC bricks.

Practicality of physical recycling method for waste polymer composites exampled via high density polyethylene/automobile shredder residue composites

AbstractWith the booming of automobiles industry, the recycling of automobile shredder residue (ASR) with complicated constitutes gradually become an urgent issues owing to its difficulty for traditional recycling. Herein, solid‐state shear milling (S3M) technology which can control the domain size of the various polymers in blend was applied to overcome the mismatch of viscosity and poor compatibility of ASR and thus modify the processability to match practical manufacturing. Resultantly, the melt processing of ASR was achieved and a high‐density polyethylene (HDPE)/ASR composite was also prepared with more optimal mechanical properties (tensile strength: 53.2 MPa, impact strength: 36.9 kJ/m2), compared with commercially available recycled PE. This work not only provided a feasible application route for the recycling of ASR material, but also demonstrated the optional methodology for recycling polymer waste with complicated component via physical recycling way.

How the physio-chemical properties of char from the pyrolysis of Automotive Shredder Residue (ASR) influences its future uses

Abstract Pyrolysis of ASR is an emerging technology which may increase circularity in End-of-Life Vehicle (ELV) waste recycling. To scale up from the current pilot scale, physiochemical characterisation of the by-products is required to determine their utilisation. This paper explored how the physiochemical properties of char from different pyrolysis fractions influence secondary uses. ASR was pyrolysed in a pilot-scale unit capable of processing 100 kg h−1 at 900 °C, producing 480 kg of char from which samples were taken for analysis. Three types of pyrolysis char were identified: (i) coarse char (CC) (ii) medium char (MC) and (iii) fine char (FC). Physical (particle size, moisture content and surface analysis) and chemical (calorific value, organic and inorganic elemental analysis) analysis was conducted. Physical and chemical differences were determined between char fractions: CC had the highest particle size (800 µm; mean 353.5 µm) calorific value (14,544 kcal g−1) and metal concentration; the relationship was CC &gt; MC &gt; FC. Organic elemental analysis indicated %C was highest under FC (80.29 %) and %S was highest in CC (1.04 %). Findings from this experiment provided initial insight into the differences in properties of char fractions from ASR pyrolysis. Potential future uses in char commercial markets were evaluated, with upgrading recommendations provided.