AUTOMOTIVE RCYCLING
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The current process of End of Life Vehicles (ELV) recycling leaves 25% of the vehicle weight going to landfill. This is mainly made up of non-metallic material such as plastic, rubber and glass.
CARE (the Consortium for Automotive Recycling) is a collaborative project, of Vehicle Manufacturers and Vehicle Dismantlers, aimed at reducing the amount of vehicle weight going to landfill from the disposal of ELVs. They have developed potential recycling routes for several non-metallic materials which when adopted, could reduce the amount of residual material going to landfill, to 18%, as of today. By 2015 the aim is to reduce the amount of vehicle weight going to landfill to 5%.
CARE's membership is currently made up of ten car manufacturers
and a growing number of dismantling and recycling operations. The car manufacturers
are:
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Dismantlers in the CARE group have direct access to product information from the relevant manufacturers to assist, for example, in the identification and segregation of the various types of plastic on a specific model of car. The project encompasses all makes and types of car now being taken off the road in Britain. It is estimated that in the first year the dismantlers involved in the CARE group processed some 20,000 cars.
Another important activity for the CARE manufacturers is to create a more stable market for recycled materials. All the participating car producers are committed to a policy of specifying recycled materials, wherever they meet the functional and quality criteria for current and future models. This will contribute to an increased demand for such material, improving the economics of any recycling process.
2. Current Process
When a car reaches the end of its useful life, it is normally sold to a vehicle dismantler. Currently the minimum price paid for an old vehicle is £30 - £40, but a recent Insurance write-off can attract significant sums. The dismantler will remove the parts that can be sold and then sell the remaining bulk to a shredder operator.
Shredders are high capacity hammer mills that will break the hulk into fist sized parts. In subsequent processing the ferrous and non-ferrous metals are extracted for recycling and the residue is normally sent to landfill. This residual consists of rubber, plastic, glass, dirt and other non-metallic materials.
It is believed that about 1.3 million vehicles come to the end of their lives each year in the UK. This figure has to be estimated because the annual taxing and the eventual deregulation of old vehicles is not monitored satisfactorily, and data is not available from all dismantlers. It is estimated that over 23 million cars are operating in the UK. There are about 3000 - 4000 dismantlers operating in the UK who feed 30 - 40 shredders, sometimes through the intermediary of a shear operator who will reduce the vehicle to improve transport costs.
The current recycling rate of around 75% is probably the highest of any complex consumer product. There remains, however, environmental concerns are now being addressed. The vehicle fluids could pollute land and water courses if they are allowed to remain in the vehicle during the disposal process. The non-metallic materials, which currently go to landfill, could be recycled and reduce the burden on virgin resources. The shredder residue has a significant calorific value. The use of shredder residue as a fuel could potentially reduce the demand for finite fossil fuels.
3. Rubber Recycling
A typical medium size car contains approximately 5% (50 kg) by weight of rubber, the majority coming from tyres. Using existing figures rubber represents 20% by weight, of the residual, material that goes to landfill.
Of the 30-35 million scrap tyres arising each year, it is estimated (by the Government/Industry Working Group) that 25% are retreaded, 20% incinerated with energy recovery, 10% recycled (granulated or crumbed), 5% reused (farms, fenders etc.) and 40% landfilled (becoming more difficult), illegally dumped or stock piled.
The European Commission now considers scrap tyres as a 'Priority waste stream'. A working group is developing legislation to reduce their environmental impact. Harsh targets are likely to be set.
The recycling
strategy of Reduce, Reuse, Recycle, Recover seems probable. This is to
encourage the reduction of waste generation, reuse in original form, recycling
and recovery of resources (material or energy). Only then should landfill
become an option.
Tyre manufacturers are already investigating designs of tyres that are lighter and more wear resistant and tyres that incorporate recycled rubber content.
There are a number of options for increasing reuse, recycling and recovery:
Retreading
A tyre casing in good condition, at the time of scrapping, can have
new tread added. UK retreaders are currently importing casings due to a
shortage of acceptable casings available in the UK.
Crumbing
Tyres are shredded and the rubber granulated for use in other products,
sports surfaces, paints, flooring, etc.
Pyrolysis
Heating tyres without air so the gas, oil and carbon can be reprocessed.
Incineration
Tyres are burnt to extract their energy value, e.g. Elm Energy.
Cement Industry
The tyres can be used as a fuel in the manufacture of cement.
All these methods work within changing market forces and legislation. They are, however, continually moving towards a reduction in the amount of scrap tyres that go to landfill.
4. Plastic Recycling
Around 10% (100kg) of a vehicle's weight is made up of plastic which has the potential for recycling and hence the generation of income to the dismantler.
However to achieve the maximum value for this material, a significant number of problems need to be overcome. The number of different plastics found in a typical vehicle's construction are considerable, each one being specified to satisfy exacting performance requirements. There are around 25 types of plastics, each one of which could have a number of variations in filler content, additives and colorants.
The majority of these plastics cannot be mixed together for the purpose of recovery - therefore a key issue is that of adequate segregation.
In addition, a large proportion of recoverable components are contaminated with metal clips, screws, labels, foam etc. all of which have to be removed prior to processing.
The CARE team has been working successfully with the dismantlers and material reprocessor's in exploring a number of options to achieve added value through increased quality. The initial outcome of the work suggested that specific materials should be targeted for recovery based upon their abundance within the vehicle, the potential market demand for the material and their ability to be segregated with a degree of confidence.
The materials were identified as:
5. Energy Saving
The total amount of shredder residue (SR) is estimated to be 750,000 - 800,000 tonnes per year, about 350,000 - 400,000 tonnes of which are Automotive Shredder Residue.
Thermal treatment of this residue can produce high levels of energy
and most importantly, considerably reduce the volume of material
going to landfill.
In order to assess the feasibility of thermal treatment of shredder
residue, the group is analysing the current situation in terms of:
Shredder residue carries a variety of in-feed. It mainly includes waste from ELVs, light iron and white goods e.g. fridges and cookers.
Detailed analyses
(determining in excess of 140 different parameters) of shredder residue
samples fiom different shredder processes, geographical locations, and
different times of the year, have been carried out by the group. The analyses
will continue in order to assess the variations of the SR composition and
calorific value. The suitability for incineration can then be determined.
The results of these analyses indicate that variations in composition,
calorific value and levels of pollutants are minimal.
6. Future Developments
CARE aims to push back the limits of cost effective material recycling and energy recovery in ELV recycling, as well as assuring the development of environmental protection standards.
After the current phase, it is planned that the project will continue to pilot and prove out future developments in ELV disposal and disseminate the findings. It is not planned that CARE will become an independent disposal network.
