The approximately 12 million automobiles discarded in North America each year produce some three million tons of auto fluff — non-metallic car parts such as rubber, glass, upholstery, foam rubber and plastics. This auto fluff, commonly referred to as automobile shredder residue (ASR), has traditionally been landfilled but recent research shows that there is the potential for ASR to be used in many beneficial applications.
A proven potential application of ASR is as a daily landfill cover.
There are several benefits. ASR requires only one quarter of the soil normally required. During periods of heavy rain, ASR provides better traction for landfill compaction machines and bulldozers, which increases equipment and operator safety.
Stabilized ASR is less dusty than regular daily cover and this reduces the amount of particulate matter that may be released into the atmosphere. (The presence of very fine dust particulate in the atmosphere has been linked to smog production.)
A series of joint reports from the Environment and Plastics Industry Council (EPIC) and the American Plastics Council (APC) show that the organic portion of ASR can also be used as an alternate fuel source in steel mill blast furnaces to reduce the need for coke. Likely candidates for this new process are the small- and medium-sized blast furnaces that don’t have long-established pulverized coal supplies and injection facilities.
The organic portion of the ASR must first be upgraded. Comprehensive work with eight shredders, numerous equipment suppliers and a number of experts resulted in the development of an independent module that could be appended to an existing shredder.
The new device would process ASR material to a maximum one-quarter-inch size and leave the product with a content of 7 to 10 per cent moisture, 10 per cent ash and 10,000 BTU/lb. heat. The injection of the upgraded ASR through the blast furnace to the combustion zone reduces the total amount of fuel required.
The reports found that facilities that inject upgraded ASR at a rate of 85,000 to 125,000 tonnes per year would net from US$20 to US$47.50 for every tonne of ASR that replaces coke. Environmental benefits would include the diversion of materials from landfill and a reduction in the environmental burdens associated with coke production.
A pilot project for this application is being developed.
Using ASR in the manufacture of plastic composite products is another promising potential application. A proprietary pilot plant commenced operation in Regina in 1994 under the company name XPotential Products Ltd.
A newer, world-scale facility four times larger than the Regina plant is expected to be operational some time in 2000.
The new plant will process between 15,000 and 20,000 tonnes of ASR per year. The company currently sources ASR from its own four shredders but future plans envision employing all of the 600 shredders located worldwide (250 of which are in North America).
Products include parking curbs, wheel stops, posts and other lumber-like objects. ASR offers the products UV stabilization and fire retardance, in addition to its acting as filler. Available at a cost comparable to that of pressure-treated wood, these composite products have a life span of 75 to 100 years, can withstand severe weather conditions and are unaffected by termites, road salt, oil and other detrimental influences. They are also very strong and are able to withstand cracking, warping and splintering.
Companies such as Co-Steel Lasco produce close to a million tonnes of recycled steel a year as well as considerable amounts of aluminum and other non-ferrous metals. The quantities of auto fluff and baghouse dust are substantial.
Co-Steel has upgraded its equipment and the company began to “mine” previously landfilled fluff, to run it through new capture technology and to extract more metal. Between 1995 and 1996, materials of concern that were landfilled dropped by 48 per cent, from 2,937 tonnes to 1,242 tonnes.
Cathy Cirko is the director general of the Environment and Plastics Industry Council (EPIC), a council of the Canadian Plastics Industry Association (CPIA), based in Mississauga, Ontario.