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The United States Council of Automotive Research (USCAR) under the Vehicle Recycling Partnership (VRP) along with our collaborators Argonne National Laboratory (ANL), American Plastic Council (APC) and the Association of Plastic Manufactures in Europe (APME) has been conducting research on automated recovery of plastics from shredder residue. A Belgium company Salyp NV located in Ypres, Belgium has been contracted by the VRP to demonstrate a recovery process that can separate several plastic types including polyurethane foam out of the shredder residue waste stream. One hundred metric tons of shredder residue was supplied from three different metal recycling companies (shredders) including a US metal recycler as well as two different European metal recyclers/shredders. This shredder residue was evaluated and processed by Salyp. This paper explains the separation processes along with processing efficiencies, material characterization, mass balances and the amount of plastics recovered.

Tons of shredder residue (SR), a complex mixture of plastics, foams, rubber, metals, and glass, are generated each year as a by-product from the recycling of obsolete vehicles. The Vehicle Recycling Partnership (VRP), along with our CRADA partners, is investigating ways to enable the optimum recovery and recycling of these materials. This study investigates the feasibility of recycling (PU) foam using a new chemical process by glycolysing [1, 2] two types of polyurethane (PU) foams, “dirty” and “clean”, which were recovered from SR via an industrial scale process specifically designed to separate PU foams from SR [3, 4]. In stage one of this process, the polyurethane foam is subjected to glycolysis, followed by filtration of the liquid glycolyzed product. In stage two, the glycolyzed products are used as initiators in reaction with propylene oxide to prepare novel polyurethane polyols.

Using automated separation, a mixed plastic stream can be recovered from shredder residue (SR). However, the mixed plastics may be contaminated with dirt, oils, heavy metals, and substances of concern (SOCs). To remove these contaminates from the mixed plastics, the plastics must be washed and cleaned. According to the U.S. Environmental Protection Agency (U.S. EPA), the recovered mixed plastic needs to contain less than 2 ppm of Polychlorinated Biphenyls to be introduced into commerce, thereby setting the performance criteria for the washing systems. This paper describes the performance and safety criteria for the washing systems, the selected washing processes, and the factors contributing to the economy of mixed plastics washing.

Shredder residue is a complex mix of many different materials that includes plastics, rubber, polyurethane (PU) foams, glass, metals and other materials such as rocks and dirt. The metal recyclers create this shredder residue mix as part of a recycling process to recover metals. The actual input stream for metal recycling is end-of-life automobiles, white goods and a variety of other metal-intensive parts including industrial scrap waste. This shredder residue is currently landfilled, and the European Union has implemented laws to reduce the amount of shredder residue from automobiles that can go into landfills. The Vehicle Recycling Partnership (VRP) is working with different collaborators to evaluate different technologies, including automated plastic recovery, as a means to reduce the amount of plastics that go to landfill in shredder residue.

The Vehicle Recycling Partnership (VRP) initiated feasibility studies to evaluate the use of automated separation processes to recover plastics and polyurethane (PU) foams from shredder residue. One of the prevailing issues impeding the commercial success of these processes is contamination of the shredder materials. The contaminants include dirt, oils, glass, metal fines, polychlorinated biphenyls (PCBs) and heavy metals. The presence of PCBs and heavy metals was determined in a number of mixed plastics and PU foam samples separated using an automated separation process. An aqueous cleaning approach was investigated using various commercial surfactants to determine their effectiveness for removing oils, PCBs, and heavy metals. Mass balances of processed and cleaned materials were calculated to determine the cleaning efficiencies of the various surfactants.

Approximately 20 percent by weight of each end of life automobile ends up in a waste stream known as shredder residue (SR) that goes to disposal into a land fill. When an automobile reaches the end of its useful life it enters a complex infrastructure designed to recover usable parts and materials of value, primarily the ferrous and non-ferrous metals. The remaining material, a mixture of glass, rubber, plastics and foam becomes part of SR. Based on earlier research, a new recycling process has been identified that can convert the organic material in this waste stream into a fuel oil. The Thermal Conversion Process (TCP) developed by Changing World Technologies (CWT) may make it possible to convert SR into useful products. The Vehicle Recycling Partnership (VRP) and its partners are investigating the capability of the TCP to process SR.

Most studies on the properties and recycling of automotive shredder residue (ASR) have been carried out without fully understanding the composition of the input scrap. Equally important is understanding the type of shredding process, and types of processes utilized for separation of ferrous and non-ferrous metals from the shredded material. The Vehicle Recycling Partnership (VRP) has been conducting a project:“Study of Plastic Material Recovery From Automotive Shredder Residue” [1]. One of the objectives of this VRP project is to determine the relationship between the shredder input and ASR properties. A 1995 Dodge Stratus was dismantled in detail to obtain information necessary for the project, such as material usage in the vehicle [2]. Then, under tightly controlled conditions, 14 late model Chrysler Cirrus and Dodge Stratus automobiles were shredded and processed.

A research project to determine the feasibility of utilizing polyethylene post-consumer automotive fuel tanks as a source of raw material was funded by Visteon, ExxonMobil, and was conducted by Brooks Associates. Brooks Associates launched this project in the last quarter of 2000 to demonstrate the feasibility of utilizing high-density polyethylene (HDPE) post-consumer automotive fuel tanks in combination with wood fiber to create a new material suitable as an automotive substrate. The concept for the project was based on proven technology that processes wood into fiber utilizing steam explosion. The steam explosion process was commercialized to form wood fiber as a raw material for ‘Masonite’. The product of the explosion process has also been made into a mat for further processing. This mat process is generally referred to as the ‘air-lay’ process.

Hand dismantling of end of life vehicles (ELV) may have limited use on recovering the majority of materials that will be in our future automobiles. Research is being conducted on automated methods to recover pure plastics from automotive shredder residue (ASR). As part of USCAR initiative, the Vehicle Recycling Partnership (VRP), a cooperative effort among Chrysler, Ford and General Motors undertook a study to determine the feasibility of obtaining pure plastics from ASR using density and skin flotation separation technologies. The total project concept is described in this paper including important elements such as the detailed dismantling of a baseline vehicle to define total plastics complexity, shredding vehicles, collecting ASR samples and performing R&D work on automated recovery methodologies.

The United States Field Trial was chartered by the United States Council for Automotive Research/Vehicle Recycling Partnership (USCAR/VRP) with the objective of evaluating the feasibility and viability of collecting and recycling automotive polymers from domestic End-of-Life Vehicles (ELVs). European concerns regarding vehicle abandonment risks, decreasing landfill capacity, and disposal practices have resulted in the legislated treatment of ELVs in Western Europe. The emergence of attendant material collection schemes promoting material recycling may not apply to the free-market economic conditions prevalent in North America vehicle recycling infrastructure. Although ELVs are among the most widely recycled consumer products, 15-25% of their total mass is currently discarded with no material recovery, although their residue, when permitted, is a preferred landfill day cover in some areas.