Meeting EU ELV targets: Pilot-scale pyrolysis automotive shredder residue investigation of PAHs, PCBs and environmental contaminants in the solid residue products

摘要

The EU's publication of the 2017 End-of-Life Vehicle Recycling and Recovery results reported that the UK failed to meet its targets. The Commission's data showed that the UK only achieved a rate of 94.1% falling short of the 95% target. The treatment of automotive shredder residue (ASR) using pyrolysis technologies offers a potential solution to this shortfall. The pyrolysis products could contribute to the target as well as supporting the circular economy package. However, there are questions about their hazardous nature and whether they qualify as secondary products. ASR, from a commercial plant, was processed through a pilot-scale pyrolysis unit, which separated the char into two fractions: coarse >0.1 mm and fine <0.1 mm. These were chosen as potential commercial products. Chars were produced from two processing temperatures of 800 and 1000 °C. These temperatures maximise gas production and produce the best "quality" char in terms of limiting organic contamination. It was found that the toxicity of the chars changed with both processing temperature and size fraction; with the maximum total PAHs concentration in the fine fraction at 800 °C. The coarse fractions were shown to be non-hazardous. It is suggested that some form of post-separation may be required to remove the hazardous component. The implication was that non-separated char could be classified as hazardous even if its overall characteristics were not, due to the role of dilution. If there were any questions about the status of the char this could prevent the use of ASR to meet the higher ELV target.