Every year in Europe, some 15 million cars reach the end of their lives and become end-of-life vehicles (ELVs). After dismantling of the vehicle into parts and shredding, what is left is known as the automotive shredder residue (ASR). With some 200 kg of ASR per ELV, this roughly equates to 3 million tonnes/yr of waste in Europe that is mostly being dumped in landfills. The European ELV Directive (2000/53/EC) requires Member States to achieve a reuse and recovery rate of 95% for all ELVs by average weight by 2015. Since ASR typically represents 14-20% of the ELV weight - depending on the amount of prior manual dismantling - it is widely acknowledged that developing post-shredder technologies (PST) for treating ASR is crucial to reaching the 95% target. There are two main categories of PST: mechanical sorting of the waste into different fractions that can be recycled and sold; and thermal treatment of the waste stream to generate feedstocks for energy generation. Mechanical sorting is generally recognised to be the best option from an environmental, technical and economic point of view. The PST process is an innovative mechanical process which deals with ASR and mixed scrap waste. One small-scale plant is currently operating in Belgium, with a capacity of 6 0000-8 000 tonnes/yr. However, the process currently produces outputs that are highly dependent on other markets - such as the growth of sewage sludge incineration - which presents a significant barrier to development of the technology.
The PST project's main objective was to reach an ELV recycling rate of 95% by the end of 2014 and thus allow the Netherlands to comply with the ELV Directive. It planned to do this by demonstrating and optimising a PST plant using the VW-SiCon process in the Dutch province of Gelderland. The project aimed to demonstrate the technical and financial viability of the process, and verify that product quality specifications were met. It aimed to periodically modify and fine-tune the different modules to improve this PST plant, and to improve the recycling rate of the overall process. The team also sought to develop multiple added-value applications for each output from the sorting process.
The PST project beneficiary ARN Recycling reported an End-of-Life Vehicles (ELV) recycling rate of 83.7% for material recycling and a total of 96.1% for recycling and energy recovery for 2012; and 86.1% and 96.0%, respectively, for 2014. The PST process added 2.4% to the recycling percentage during this period. In 2013, reported recycling rates were 86.0% (recycling) and 95.9% (recycling plus energy recovery). The project therefore achieved its main objective of improving ELV recycling rates and reaching a 95% ELV recovery rate during 2015 (starting from a targeted 86.1% of material recycling in 2012). This has secured Dutch compliance with the ELV Directive (2000/53/EC). The PST plant has stabilised production on an annual basis and is able to process larger volumes of shredder waste, which results in more useful end fractions and less automotive shredder waste being incinerated or landfilled in the Netherlands. Thus the project addressed the environmental impact of the annual volume of Automotive Shredder Residue (ASR) that is landfilled in Europe. In this way, the project helps implement the Waste Framework Directive (WFD: 2008/98/EC1), particularly by adhering to the EU's "waste hierarchy" approach to waste management: prevention, (preparing for) reuse, recycling, recovery for energy production and, as the least preferred option, disposal by incineration or landfill.
Optimisation as a result of project actions has allowed the PST plant to process 40 000 tonnes of ASR every year, with end fractions of a quality sufficient to achieve at least 85% material reuse and recycling. This results in more useful end products, and environmental benefits (e.g. reduced air and soil pollution) due to less shredder waste being incinerated or landfilled. Furthermore, the project has demonstrated that the PST process can be operated in a technically-viable way, and shown that quality specifications for all output fractions have been met. For the majority of end fractions, two sales channels have been created. For example, a contract was signed with a German mining and backfill operator for the mineral fraction. The coordinating beneficiary, ARN Recycling, is conducting ongoing (post-LIFE) searches to developing further outlets for plastic, fibre and mineral fractions.
The project has generated valuable lessons learned in this field, arising from the technical and innovative challenges which have occurred during the project cycle. ASR in the PST plant has emerged as a complex waste stream, containing a wide range of materials including plastics, wood, rubber, metals, fibres and glass, and the process for separating these is challenging. The project installed a prall mill to enable the separation of fine copper wires and fibre fraction, for example, but needed to modify the ventilator due to a pressure through the system which originally caused blockages when processing these materials. This strategic then led to amendments for fibre and copper recycling. In addition to generating process improvements, the project has also resulted in quality improvements. For instance, plastics with a density of less than 1.1 kg/dm3 contain 10-12% non-plastic particles; so to reduce the quantity of contaminants, the existing drum screen was replaced by a new separator that used the hardness of particles as a discriminating factor. ARN Recycling bought the first commercially-available unit to do this and reduced the contamination to 3-4%; and in the process implemented the best practice available and established a new standard. For other components, state-of-the-art models were installed from the beginning, such as the baghouse filter system for de-dusting. Although the legal limit for dust emissions in the Netherlands is 5 mg dust/Nm3, the project was able to reduce dust emissions to less than 1 mg/Nm3.
The project conducted a dissemination and communication campaign by means of newsletters, a website and media coverage. In terms of socio-economic benefits, as a result of the project, the PST plant enabled the recycling site to expand with an increase of 14 jobs (to 42 employees), with the possibility of further employment being generated as the overall optimisation of the plant progresses. Optimisation has more than doubled the plant’s capacity, and reduced the processing costs per tonne. ARN is now working toward a demonstration of how integrated recycling and production processes can be economically self-sustainability, both in the Netherlands and in the rest of the EU.
Further information on the project can be found in the project's layman report and After-LIFE Communication Plan (see "Read more" section).