Automobile shredder residue

Table 3. Representative Composition of Automobile Shredder Residue ...

This article examines the recovery of automobile shredder residue (ASR), and considers three recovery options ASR as a landfill day cover, ASR in the production of composite materials, and the pyrolysis of ASR to recover chemical feedstock. All are discussed in detail. 

Arlington, Va., 20th-21st May 1992, p.206-20. 8(13) VACUUM PYROLYSIS OF AUTOMOBILE SHREDDER RESIDUE Roy C Dubue M... 

It is reported that between 10 and 11 million cars are taken apart every year in North America once the metallic portion has been recovered from the crushing operation, the remainder - representing over 20% of the total mass or 3.5 million tons - must be eliminated. Pyrovac, in collaboration with Universite Laval and under the sponsorship of E.T.P. Technologies, recently undertook a research programme to recover valuable products from this Automobile Shredder Residue. A process flow sheet for a 4000 kg/hr plant is presented, with fixed capital investment estimated to be 5 million US dollars. Details are given. 

The process is used on petroleum sludges, used tires, biomedical waste, automobile shredder residues, bark residues and municipal solid wastes. It is limited to treating organic wastes and contaminated soil. For soil contaminated by polychlorinated biphenyls (PCBs), vacuum pyrolysis cannot destroy the PCBs but will concentrate them in the pyrolytic oils. The process cannot be used to treat mine tailings. 

G. Ando, C. Steiner, A. Selinger and K. Shin, Automobile shredder residue treatment in Japan, Proceedings of International Automobile Recycling Congress, Geneva (CH), 13-15 March 2002. 

PE = polyethylene PP = polypropylene PS = polystyrene ASR = automobile shredder residue VGO = vacuum gas oil LCO = light cycle oil. SA = Si02/ AI2O3 MOR = mordenite. TD/CD = thermal degradation followed by catalytic degradation COMB = mixed polymer and catalyst in a batch reactor COMS = mixed polymer and catalyst in a semibatch reactor FB = fixed bed flow reactor BIRR = Berty internal recycle reactor. 

An early patent by the Ford Motor Company reported the use of basic salts to degrade automobile shredder residue, a mixture containing 12.7 wt% polypropylene. With the addition of 2 g of sodium carbonate powder to 40 g of auto shredder residue, the total liquid yield increased by approximately 3%, and the overall olefin yield increased by approximately 20%. The benefit observed increased with the amount of the sodium salt added. The same effect was observed when calcium and potassium carbonates were used, but magnesium and zinc carbonate actually increased the amount of char formed. 

Argoime National Laboratory has developed a plastics separation system based on froth flotation. A series of six tanks is used, each with a specific function, depending on the plastic being recovered. The chemical solutions in each tank are chosen for the particular apphcation. It has been used for recovering selected plastics from automobile shredder residue, disassembled car parts, industrial scrap plastics, and consumer electronics. Argonne claims it is the only technology that can successfully recycle ABS with a purity greater than 99 percent. ... 

In the case of automobile shredder residues, since the automobile industry has the responsibility to reuse industrial wastes generated during the manufacturing process after the End-of-Life Vehicle Recycling Law [11] was promulgated in 2002, combustible wastes are utilized in the kiln as thermal energy. 

Roy, C., Chaala, A. Vacuum pyrolysis of automobile shredder residues. Resour. Conserv. Recycl. 32, 1-27 (2001)... 

More than 90% of the total number of used cars are shredded for recovery and disposal of their material constituents [7]. Each recycled automobile leaves around a hundred kilograms of Automotive Shredder Residue (ASR). This... 

The automotive plastics that are not reused in the form of resalable parts end up in an industrial waste stream from the automobile shredders called automotive shredder residue (ASR) [45], ASR contains residual ferrous and nonferrous... 

Obsolete automobiles are typically shredded for the recovery of ferrous scrap. The nonmetallic fraction of shredded automobiles is auto shredder residue (ASR), a heterogeneous mixture of plastics, glass, rubber, fibers, foam, upholstery, dirt and fines. ASR may typically be contaminated with any of the original constituents of an automobile such as brake fluid, steering fluid, motor oil, gasoline or heavy metals. It is estimated that 250-275 lb. of plastic are used in a 3,500 lb. auto and that up to 1.2 million tons of waste plastic from ASR are generated per year [Bonsignore ct al., 1991]. A breakdown of automotive plastic scrap for the 1981 model year has shown that the thermoplastics ABS, PUR, PP and PVC comprise 65% of waste plastic. 

Apart from the reprocessors of post consumer plastics, other companies have continued to specialize in waste plastics from industrial and commercial operations. The recycling of plastic pallet wrap is expanding across the country. Used electrical wire and cable is being reprocessed primarily for the recovery of metals however a number of specialized operations recycle the cable insulators, polyethylene and polyvinyl chloride. Similarly a few facilities exist to recycle waste automotive trim and foam polystyrene packaging. A considerable effort is being expended to find applications for plastic auto shredder residue which is the by product of the automobile recycling industry which currently recovers metals from end of life automobiles. At present viable applications are still understudy and current residues continue to be landfilled. 

About 95% of all automobiles are recycled however, recycling is generally limited to the 75% by weight of the vehicle that is metallic. The remaining 25%, including a significant amount of plastics, have been difficult to recycle cost effectively (46). As a result, most of that remaining material, known as automotive shredder residue (ASR), is disposed of in landfills. 

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