Guidance on best available techniques and best environmental practices for the recycling and disposal of wastes containing polybrominated diphenyl ethers (pbdes) listed under the Stockholm Convention on Persistent Organic Pollutants
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- Recycling by improved depollution and post-shredding techniques
Shredder plantsShredder plants for the treatment of end-of-life vehicles are listed in Annex C of the Stockholm Convention as a source that has the potential to form and release unintentionally produced POPs; they are therefore described in the Stockholm Convention BAT/BEP guidelines (Stockholm Convention 2007, Part III Source category (k)). An overview of the process is shown in Figure 5-2. 
(Stockholm Convention, 2007) Figure 5‑12: Overview of the shredder process Many components of vehicles are made of non-ferrous materials, such as copper, aluminium and zinc. In the shredding process, magnetic separation is used to remove the magnetic ferrous fraction from other materials. The non-ferrous metals, such as copper and aluminium, are normally sorted out at a later stage by manual or optical separation. The remainder is the ASR and is estimated at between 15% and 30% of the weight of ELVs (Stockholm Convention, 2007; Vermeulen et al., 2011). ASR consists of glass, fibre, rubber, automobile liquids, plastics, PUR foam and dirt (see Figure 5-3) and is normally further separated in the “light fraction” (containing PUR foam, most of the textile and plastic) and a “heavy fraction” (see Figure 5-1). Since shredder plants can generate dust and other releases (including the above-mentioned pollutants) collective and technical measures such as suction and ventilation systems should be implemented to control the safety and health hazards. Also appropriate personal protective equipment should be used. 
(Stockholm Convention, 2007) Figure 5‑13: Composition of shredder waste Recycling by improved depollution and post-shredding techniquesAs mentioned in section 5.2.1, a significant share of materials can be recycled. The possible POP-PBDE-containing materials (PUR foam and plastic/textiles from the interior) are normally not listed as materials being recycled (see Table 5-1). Due to the increased pressure on material recycling, however a higher share of the polymer fraction will need to be recycled in future. According to Ferraõ et al. (2006), increasing the recycling of the polymers from ASR is the key objective e.g. the European reuse and recycling target of 95% by 2015. Since polymers are increasingly used in cars, this fraction will become even more relevant in future. Therefore several BAT/BEP facilities to process ASR have been established in Europe (see Table 5-2). The PUR foam (considered to contain the main POP-PBDE fraction)34 is approximately 5%, and up to 15%, of the ASR fraction (in average approximately 16 kg PUR foam/car); however, it makes up over 30% of its volume (Hoffman, 2008). The US industry says that the viability of foam recovered from shredder residue for the foam-rebond market depends on two key factors: (i) development of an economical process for recovering foam from shredder residue, and (ii) confirmation that the recovered foam meets quality requirements (Hoffman, 2008). The POP-PBDE-content could become one of the quality requirements. Argonne National Laboratory has developed a polymer separation system based on froth flotation (Hoffman, 2008). A series of six tanks is used, each with a specific function, depending on the polymer being recovered. The chemical solutions in each tank are chosen for the particular application. This system has been used for recovering selected polymers from ASR, disassembled car parts, industrial scrap plastics, and consumer electronics (Selke, 2006). Argonne has found that the highest-quality foam comes from dismantling and then washing the foam from seats. But it claims that manual separation of foam is not economical for industrial countries (Hoffman, 2008; UNEP, 2010b). In 2004 NV Salyp of Ypres, Belgium commissioned the Salyp ELV Centre, which operated the Argonne technology under licence, to recover PUR foam and other polymers from shredder residue. It is reported to have an operational process capacity of 6 tonnes of ASR per hour. The plant also used technology licensed from a German firm, KUTEC, for separating different types of thermoplastics from the Argonne technology reject stream. The Argonne technology separates the fluff into three streams: fines, foam, and a thermoplastic-rich stream. The foam stream is cleaned and sold for markets such as rebond foam in carpet underlay and for padding in automobiles (Selke, 2006; UNEP, 2010b). Other facilities take polymer-enriched fractions from the shredding process of vehicles. One precondition here is a pre-processing step to generate a polymer enriched fraction with 70% to 80% polymersso that the transport to a plastic recycling facility becomes economically viable (Slijkhuis, 2011). Table 5‑6: Overview of post-shredder technologies35 
(Vermeulen et al., 2011) Directory: Portals Portals -> Draft I film Screening Portals -> Black History Academic Bowl arts & entertainment Portals -> Setting the Table for a Successful Season Download 2.99 Mb. Share with your friends:
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