Car Fluff Research Articles

The pyrolysis and gasification pathways of automotive shredder residue targeting the production of fuels and chemicals

Automotive shredder residue (ASR), also referred to as car fluff, is the 15-25% of end-of-life vehicle’s mass remaining after de-pollution, dismantling, shredding of the hulk and removal of metals from the shredded fraction. ASR typically consists of metals, plastics, rubber, textile, wood and glass, and is commonly landfilled. The use of ASR as a fuel in incineration processes is controversial since toxic pollutants can be generated as by-products if operational conditions and gas cleaning systems are not carefully controlled. Thermochemical treatment of ASR consists of advanced technology processes that convert ASR components liable to decomposition under the application of heat into liquids and/or gases and a solid residue containing metals. Within the thermochemical treatment options for ASR, pyrolysis and gasification are generally considered as the emerging technologies. The pyrolysis process uses medium temperatures (400-600°C) and an oxygen-free environment to decompose ASR chemically, thus producing minimum emissions and allowing metals to be recovered. Gasification is operated at higher temperatures (>700-800°C) and typically uses air as a gasification agent, which raises some issues in terms of emissions. Lab and pilot-scale plants fed with ASR have been built using both technologies, also considering a combination of them. The aim of this paper is the identification of the best conversion pathway for the production of transportation fuels, aviation fuels or chemicals (hydrogen, methanol, etc.) from ASR. The intermediate products from gasification and pyrolysis are used as feedstock in secondary processes for the production of the final products. The heterogeneous and complex composition of ASR raises several challenges upon its thermochemical treatment, so that the second step of the conversion process is typically not even addressed. Instead, this further step is fundamental to obtain some valuable products that can directly replace fossil derived fuels or chemicals. The updated picture presented in this work should help identify the main advantages and drawbacks of the pyrolysis and gasification processes when considered part of an overall ASR to fuels or chemicals plant.

Occurrence and sorption behaviour of bisphenols and benzophenone UV-filters in e-waste plastic and vehicle fluff

Bisphenols and benzophenone UV-filters are hazardous, high production volume chemicals. There is concern that these contaminants could leach into the environment or be recycled into new products during waste management. To investigate this, nine bisphenols and five benzophenones were quantified in Norwegian e-waste and car fluff. To understand their leachability, equilibrium passive sampling methodology, using polyoxymethylene (POM), was calibrated for these substances, many of which for the first time. This method can differentiate freely dissolved substances in the aqueous phase from those sorbed to suspended colloids and microplastics in the leachate water. Equilibrium POM partitioning was reached within 14 days of shaking; all bisphenols and benzophenone UV-filters exhibited linear isotherms (R2 ranged from 0.83 to 1.0), when deriving POM-water partition coefficients (KPOM). Bisphenol A and bisphenol F displayed the highest concentrations, with maximum levels of 246,000 and 42,400 ng g−1, respectively. Logarithms of waste-water partition coefficients (log Kwaste) ranged from 1.7 (benzophenone 2) to 4.5 (bisphenol P). The established KPOM values agreed with measured Kwaste values (within a factor of ~3), unlike octanol-water partition coefficients. This indicated that POM is a better surrogate for waste plastic partitioning than octanol. Results are discussed in the context of assessing risks from waste management in a circular economy.

Lab-scale pyrolysis of the Automotive Shredder Residue light fraction and characterization of tar and solid products

The general aim of this study is the recovery of Automotive Shredder Residue (ASR). The ASR light fraction, or car fluff, that was collected at an Italian shredding plant was pyrolysed at various temperatures (500–800°C) in a lab-scale reactor. The condensable gases (tar) and solid residue yields increased with decreasing temperature, and these products were characterized to suggest a potential use to reclaim them. The higher heating value (HHV) of tar was 34–37MJ/kg, which is comparable with those of fossil fuels. Furthermore, the ash content was low (0.06–4.98%). Thus, tar can be used as an alternative fuel. With this prospect, the concentrations of polychlorinated dibenzodioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) in tar were determined. The toxicity of tar changes with temperature (1–5ng I-TEQ/g), and the PCDFs significantly contribute to tar toxicity, which was 75–100% with a maximum of 99.6% at 700°C. Regarding the characterization of the solid residue, the low HHV (2.4–3.3MJ/kg) does not make it suitable for energy recovery. Regarding material recovery, we considered its use as a filler in construction materials or a secondary source for metals. It shows a high metal concentration (280,000–395,000mg/kg), which is similar at different pyrolysis temperatures. At 500°C, polycyclic aromatic hydrocarbons (PAHs) were not detected in the solid residue, whereas the maximum total PAH concentration (19.41ng/g, 700°C) was lower than that in fly ash from MSWI. In conclusion, 500°C is a suitable pyrolysis temperature to obtain valuable tar and solid residue.

Recycling of non-metallic automotive shredder residues and coal fly-ash in cold-bonded aggregates for sustainable concrete

Abstract In order to achieve the relevant objectives of EC directive on end-of-life of vehicles (2000/53/CE), innovative solutions such as recycling automotive shredder residues are required. This paper deals with the design and characterization of concrete mixtures containing artificial aggregates obtained through the cold-bonding pelletization of non-metallic fraction of automotive shredder residues, commonly named car fluff. In this work, car fluff was pelletized with blended cementitious mixtures containing coal fly ash, another industrial by-product. Produced artificial aggregates were characterized by determining main environmental, physical and mechanical properties. Then, they were employed as lightweight aggregates for manufacture of sustainable concrete. Experimental results showed good mechanical properties of concrete containing these aggregates and leaching behaviour of hardened specimens confirmed the environmental effectiveness of the here studied car fluff recovery process.

Low Technological Biological Treatment of Source Separated Waste in a Biocell

In 2009 the Norwegian government banned biodegradable waste in landfills to mitigate climate gas production. To be able to stabilize source separated waste before landfilling a constructed biocell has been tested during a four year period. The research is part of a pilot project organized by Avfall Norge. A total amount of 12 000 tons of waste from both industry and households were embedded in the biocell. Before loading, the waste fractions were characterized both in macro and micro scale. Anaerobic testing in lab scale documented the methane potential in different waste fractions. Especially car fluff contained toxic components which suppressed biodegradation. To avoid greenhouse gas leakage the biocell was constructed as a closed system with synthetic capping and gas wells coupled to a compressor. While the biogas was flared the leachate was collected and recycled. Leachate contains both nutrients and DOC which is supposed to increase the biological activity. During the first part of the test period the BOD/COD was above 0.5 before it declined. In addition both inorganic and organic environmental harmful components were analyzed in the leachate. Levels of heavy metal decreased during treatment. The methane production was detected on-line with IR. Both the production and gas phase concentration varied during the test period. A total of five gas wells were positioned at different levels in the biocell. Only one of them produced biogas for a considerable period. This presentation will focus on biocell construction and waste degradation related to variation in leachate constituents as a function of time.

Life-cycle assessment of a Waste-to-Energy plant in central Norway: Current situation and effects of changes in waste fraction composition

Waste-to-Energy (WtE) plants constitute one of the most common waste management options to deal with municipal solid waste. WtE plants have the dual objective to reduce the amount of waste sent to landfills and simultaneously to produce useful energy (heat and/or power). Energy from WtE is gaining steadily increasing importance in the energy mix of several countries. Norway is no exception, as energy recovered from waste currently represents the main energy source of the Norwegian district heating system. Life-cycle assessments (LCA) of WtE systems in a Norwegian context are quasi-nonexistent, and this study assesses the environmental performance of a WtE plant located in central Norway by combining detailed LCA methodology with primary data from plant operations. Mass transfer coefficients and leaching coefficients are used to trace emissions over the various life-cycle stages from waste logistics to final disposal of the ashes. We consider different fractions of input waste (current waste mix, insertion of 10% car fluff, 5% clinical waste and 10% and 50% wood waste), and find a total contribution to Climate Change Impact Potential ranging from 265 to 637gCO2eq/kg of waste and 25 to 61gCO2eq/MJ of heat. The key drivers of the environmental performances of the WtE system being assessed are the carbon biogenic fraction and the lower heating value of the incoming waste, the direct emissions at the WtE plant, the leaching of the heavy metals at the landfill sites and to a lesser extent the use of consumables. We benchmark the environmental performances of our WtE systems against those of fossil energy systems, and we find better performance for the majority of environmental impact categories, including Climate Change Impact Potential, although some trade-offs exist (e.g. higher impacts on Human Toxicity Potential than natural gas, but lower than coal). Also, the insertion of challenging new waste fractions is demonstrated to be an option both to cope with the excess capacity of the Norwegian WtE sector and to reach Norway’s ambitious political goals for environmentally friendly energy systems.

RECOVERY OF METALS FROM ZINC-CARBON AND ALKALINE SPENT BATTERIES BY USING AUTOMOTIVE SHREDDER RESIDUES

ABSTRACT The main aim of this work is the thermal recovery of manganese and zinc from a mixture of zinc-carbon and alkaline spent batteries containing 40.9% of Mn and 30.1% of Zn after a pre-liminary physical treatment followed by the removal of mercury. Separation of the metals is car-ried out on the basis of their different phase change temperatures, in fact the boiling point of mercury and zinc are 357 °C and 906 °C, respectively, and the melting point of Mn 3 O 4 , the main Mn-bearing phase in the mixture, is 1564 °C. After wet comminution and sieving to remove the anodic collectors and most of the chlorides contained in the mixture, chemical and X-ray powder diffraction (XRPD) analyses were per-formed. The mixture was initially heated in an air flow at temperatures ranging from 300 °C to 400 °C to eliminate mercury, then, the flow of air was turned into an inert carbon dioxide at-mosphere. The volatilization of metallic zinc starts at a temperature 850 °C. At higher temperature the reduction of zinc oxide and subsequent volatilization of metallic zinc is carried out by the carbon present in the original mixture or in the automotive shredder residue (car fluff) added from the outside. By optimization of temperature, stoichiometric ratio and residence time, a product suit-able for production of new batteries after refining was obtained. The treatment residue consist-ed of manganese and iron oxides that could be used to produce manganese-iron alloys.

Aluminium flows in vehicles: enhancing the recovery at end-of-life

The transportation sector constitutes the major end-use market for aluminium-containing products and expectations for the future do indicate that aluminium will increase at 140 kg per vehicle. Moreover, up to 75 % aluminium recycled in Europe is used in transportation: thus, metal scrap recovered from ELVs is a key lever to act for closing material cycles. However, although the management chain of ELVs has an established procedure and aluminium scrap is usually recovered in shredding plants, a considerable fraction of the metal particles ends up in the light fraction called car fluff and is then landfilled. In this study we investigated potential of enhancing the recovery of aluminium scrap from the light fluff treatment. With this goal, the quantity of aluminium embedded in the Italian transport sector in the last 62 years was estimated, and a campaign of characterization in size and shape distribution of aluminium particles in the light fluff output has been carried out. The results estimated up to about 560,000 tons of metal are potentially recoverable from the treatment of light fluff at current operating conditions, but relevant improvements may be achieve when size and shape distribution criteria are adopt to implement eddy currents separation for a quantitative metal recovery.

Viability study of automobile shredder residue as fuel

Car Fluff samples collected from a shredding plant in Italy were classified based on particle size, and three different size fractions were obtained in this way. A comparison between these size fractions and the original light fluff was made from two different points of view: (i) the properties of each size fraction as a fuel were evaluated and (ii) the pollutants evolved when each size fraction was subjected to combustion were studied. The aim was to establish which size fraction would be the most suitable for the purposes of energy recovery. The light fluff analyzed contained up to 50wt.% fines (particle size<20mm). However, its low calorific value and high emissions of polychlorinated dioxins and furans (PCDD/Fs), generated during combustion, make the fines fraction inappropriate for energy recovery, and therefore, landfilling would be the best option. The 50–100mm fraction exhibited a high calorific value and low PCDD/F emissions were generated when the sample was combusted, making it the most suitable fraction for use as refuse-derived fuel (RDF). Results obtained suggest that removing fines from the original ASR sample would lead to a material product that is more suitable for use as RDF.

Auto shredder residue recycling: Mechanical separation and pyrolysis

Directive 2000/53/EC sets a goal of 85% material recycling from end-of-life vehicles (ELVs) by the end of 2015. The current ELV recycling rate is around 80%, while the remaining waste is called automotive shredder residue (ASR), or car fluff. In Europe, this is mainly landfilled because it is extremely heterogeneous and often polluted with car fluids. Despite technical difficulties, in the coming years it will be necessary to recover materials from car fluff in order to meet the ELV Directive requirement. This study deals with ASR pretreatment and pyrolysis, and aims to determine whether the ELV material recycling target may be achieved by car fluff mechanical separation followed by pyrolysis with a bench scale reactor. Results show that flotation followed by pyrolysis of the light, organic fraction may be a suitable ASR recycling technique if the oil can be further refined and used as a chemical. Moreover, metals are liberated during thermal cracking and can be easily separated from the pyrolysis char, amounting to roughly 5% in mass.Lastly, pyrolysis can be a good starting point from a “waste-to-chemicals” perspective, but further research should be done with a focus on oil and gas refining, in order both to make products suitable for the chemical industry and to render the whole recycling process economically feasible.

Automobile shredded residue valorisation by hydrometallurgical metal recovery

The aim of this work was developing a hydrometallurgical process to recover metals from automobile shredded residue (or car fluff). Automobile shredded residue (ASR) was characterised by particle size distribution, total metal content and metal speciation in order to guide the choice of target metals and the operating conditions of leaching. Characterisation results showed that Fe is the most abundant metal in the waste, while Zn was the second abundant metal in the fraction with diameter lower than 500 μm. Sequential extractions denoted that Zn was easily extractable by weak acid attack, while Fe and Al required a strong acid attack to be removed. In order to recover zinc from <500 μm fraction leaching tests were operated using acetic acid, sulphuric acid and sodium hydroxide at different concentrations. Sulphuric acid determined the highest zinc extraction yield, while acetic acid determined the highest zinc extractive selectivity. Sodium hydroxide promoted an intermediate situation between sulphuric and acetic acid. Zn recovery by electro winning using acetic leach liquor determined 95% of Zn electro deposition yield in 1 h, while using sulphuric leach liquor 40% yield in 1 h and 50% yield in 2 h were obtained. Simulation results showed that the sulphuric leaching process was more attractive than acetic leaching process.

End-of-Life Vehicles management: Italian material and energy recovery efficiency

Each European Member State must comply with Directive 2000/53/EC recycling and recovery targets by 2015, set to 85% and 95%, respectively. This paper reports a shredder campaign trial developed and performed in Italy at the beginning of 2008. It turns out to be the first assessment about the critical aspects belonging to the Italian End-of-Life Vehicles (ELVs) reverse supply chain involving 18 dismantling plants, a shredder plant and 630 ELV representatives of different categories of vehicles treated in Italy during 2006. This trial aims at improving the experimental knowledge related to ELVs added waste, pre-treatment, part reuse, recycling and final metal separation and car fluff disposal. Finally, the study also focuses on the calculation of the effective Italian ELV recycling rate, which results equal to 80.8%, and auto shredder residue (ASR) characterization. According to the results obtained in this work, ASR still contains up to 8% of metals and 40% of polymers that could be recovered. Moreover, physical–chemical analysis showed a Lower Heat Value of almost 20,000 kJ/kg and revealed the presence of pollutants such as heavy metals, mineral oils, PCBs and hydrocarbons.

Automotive shredder residue (ASR) characterization for a valuable management

Car fluff is the waste produced after end-of-life-vehicles (ELVs) shredding and metal recovery. It is made of plastics, rubber, glass, textiles and residual metals and it accounts for almost one-third of a vehicle mass. Due to the approaching of Directive 2000/53/EC recycling targets, 85% recycling rate and 95% recovery rate in 2015, the implementation of automotive shredder residue (ASR) sorting and recycling technologies appears strategic. The present work deals with the characterization of the shredder residue coming from an industrial plant, representative of the Italian situation, as for annual fluxes and technologies involved. The aim of this study is to characterize ASR in order to study and develop a cost effective and environmentally sustainable recycling system. Results show that almost half of the residue is made of fines and the remaining part is mainly composed of polymers. Fine fraction is the most contaminated by mineral oils and heavy metals. This fraction produces also up to 40% ashes and its LHV is lower than the plastic-rich one. Foam rubber represents around half of the polymers share in car fluff. Moreover, some chemical–physical parameters exceed the limits of some parameters fixed by law to be considered refuse derived fuel (RDF). As a consequence, ASR needs to be pre-treated in order to follow the energy recovery route.

Recycling of automobile shredder residue with a microwave pyrolysis combined with high temperature steam gasification

Presently, there is a growing need for handling automobile shredder residues – ASR or “car fluff”. One of the most promising methods of treatment ASR is pyrolysis. Apart of obvious benefits of pyrolysis: energy and metals recovery, there is serious concern about the residues generated from that process needing to be recycled. Unfortunately, not much work has been reported providing a solution for treatment the wastes after pyrolysis. This work proposes a new system based on a two-staged process. The ASR was primarily treated by microwave pyrolysis and later the liquid and solid products become the feedstock for the high temperature gasification process. The system development is supported within experimental results conducted in a lab-scale, batch-type reactor at the Royal Institute of Technology (KTH). The heating rate, mass loss, gas composition, LHV and gas yield of producer gas vs. residence time are reported for the steam temperature of 1173 K. The sample input was 10 g and the steam flow rate was 0.65 kg/h. The conversion reached 99% for liquids and 45–55% for solids, dependently from the fraction. The H 2:CO mol/mol ratio varied from 1.72 solids and 1.4 for liquid, respectively. The average LHV of generated gas was 15.8 MJ/N m 3 for liquids and 15 MJ/N m 3 for solids fuels.

Thermal process of fluff: Preliminary tests on a full-scale treatment plant

Until only recently fluff has been largely disposed of in controlled landfill sites. However, in Europe environmental regulations, including the EU Landfill Directive 1999/31/EC and ELV (End of Life Vehicle) Directive 2000/53/EC, have dramatically increased the pressure on all stakeholders to develop alternative solutions. As increasingly stringent legislation forces Shredder Residues (SR) to be diverted from landfilling, newly developed technologies will be in a position to compete for the market value of disposing of the waste. However, the fluff waste stream is so variable that it cannot be automatically assumed that processes developed for one type of fluff will prove to be suitable for other fluff streams. This situation has contributed towards convincing stakeholders to withhold investment funds or delay taking decisions as to how best to proceed; as a consequence, very few technologies have been fully developed on a commercial basis. It is of particular interest therefore that commercial alternatives to be used in dealing with this complex waste stream should be identified. The present paper illustrates the findings of a full-scale thermal treatment performed on SR samples obtained from various shredding plants. The outcome of the study provides an important contribution towards assessing the feasibility and reliability of the process, thus constituting a basic prerequisite for process performance evaluation. The full-scale plant, designed for the thermo-valorization of tyres, was purpose-modified to allow for fluff combustion. Three different fluff compositions (car fluff with different percentage of shredding, whites and 100% car fluff) were taken into consideration. Both the raw samples and solid products were thoroughly characterized. Combustion emissions were continuously analyzed during the test period, alternatively operating for tyre and fluff combustion. Classification of combustion residues for landfill disposal was carried out indicating only 2% (ashes) as hazardous waste. Preliminary results, obtained from a unsophisticated thermodynamic analysis of the process, indicated a value of 0.61 for energy efficiency parameter calculated in accordance with the Directive 2008/98/EC. To conclude, the thermal treatment investigated may be deemed an appropriate technique for use in managing fluff. Indeed, values obtained for all organic and inorganic contaminants released into the atmosphere were lower than legal limits prescribed, and a significant energy content was recovered from waste fractions.

Automobile Shredder Residue (ASR) destruction in a plasma gasification reactor

Test results on Automobile Shredder Residue (ASR), or car fluff, demonstrated destruction efficiency and safe conversion to synthesis gas and a glass residue, in a plasma gasification system. The synthesis gas consists primarily of hydrogen and carbon monoxide in the range between 20 and 22 vol-% respectively, or 45 and 55 vol-% dry basis, when corrected for nitrogen. In dry reforming operation, carbon dioxide conversion approached 90%. The system is designed to work with oxygen in autothermal conditions, reducing thus the electric power requirement for the plasma reactor. The vitrified residue leach rate makes the product suitable for construction works.

97/03706 Model for predicting catalytic and non-catalytic liquefaction of coal

Car fluff is the waste produced after end-of-life-vehicles (ELVs) shredding and metal recovery. It is made of plastics, rubber, glass, textiles and residual metals and it accounts for almost one-third of a vehicle mass. Due to the approaching of Directive 2000/53/EC recycling targets, 85% recycling rate and 95% recovery rate in 2015, the implementation of automotive shredder residue (ASR) sorting and recycling technologies appears strategic. The present work deals with the characterization of the shredder residue coming from an industrial plant, representative of the Italian situation, as for annual fluxes and technologies involved. The aim of this study is to characterize ASR in order to study and develop a cost effective and environmentally sustainable recycling system. Results show that almost half of the residue is made of fines and the remaining part is mainly composed of polymers. Fine fraction is the most contaminated by mineral oils and heavy metals. This fraction produces also up to 40% ashes and its LHV is lower than the plastic-rich one. Foam rubber represents around half of the polymers share in car fluff. Moreover, some chemical–physical parameters exceed the limits of some parameters fixed by law to be considered refuse derived fuel (RDF). As a consequence, ASR needs to be pre-treated in order to follow the energy recovery route.