37 research outputs found
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Recovery of flexible polyurethane foam from shredder residue.
Argonne National Laboratory has developed a patented, continuous process for the recovery of flexible polyurethane foam (PUF) from auto shredder residue (ASR). To test the process, Argonne researchers conceived of, designed, and built a continuous foam washing and drying system that was pilot-tested at a shredder facility for six months. Economic analysis of the process, using manufacturers' quotes and operating data from Argonne's pilot plant, indicates a payback of less than two years for a plant producing about 1,000 ton/yr of foam. Samples of clean foam were shipped to three major foam reprocessors; all three indicated that the quality of the PUF recovered by the Argonne process met their requirements. Tests of the recovered foam by an independent testing laboratory showed that the recycled foam met the specifications for several automotive applications, including carpet padding, headliner, and sound-suppression support materials. Recovery of foam reduces the mass and the volume of material going to the landfill by about 5% and 30%, respectively. Annually, recovery will save about 1.2 x 10{sup 12} Btu of energy, cut the amount of solid waste being landfilled by about 150,000 tons, and eliminate the emission of about 250 tons of volatile organic compounds (VOCs) into the air
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End-Of-Life Vehicle Recycling: State of the Art of Resource Recovery From Shredder Residue.
Each year, more than 50 million vehicles reach the end of their service life throughout the world. More than 95% of these vehicles enter a comprehensive recycling infrastructure that includes auto parts recyclers/dismantlers, remanufacturers, and material recyclers (shredders). Today, about 75% of automotive materials are profitably recycled via (1) parts reuse and parts and components remanufacturing and (2) ultimately by the scrap processing (shredding) industry. The process by which the scrap processors recover metal scrap from automobiles involves shredding the obsolete automobiles, along with other obsolete metal-containing products (such as white goods, industrial scrap, and demolition debris), and recovering the metals from the shredded material. The single largest source of recycled ferrous scrap for the iron and steel industry is obsolete automobiles. The non-metallic fraction that remains after the metals are recovered from the shredded materials (about 25% of the weight of the vehicle)--commonly called shredder residue--is disposed of in landfills. Over the past 10 to 15 years, a significant amount of research and development has been undertaken to enhance the recycle rate of end-of-life vehicles (ELVs), including enhancing dismantling techniques and improving remanufacturing operations. However, most of the effort has focused on developing technology to recover materials, such as polymers, from shredder residue. To make future vehicles more energy efficient, more lighter-weight materials--primarily polymers and polymer composites--will be used in manufacturing these vehicles. These materials increase the percentage of shredder residue that must be disposed of, compared with the percentage of metals. Therefore, as the complexity of automotive materials and systems increases, new technologies will be required to sustain and maximize the ultimate recycling of these materials and systems at end-of-life. Argonne National Laboratory (Argonne), in cooperation with the Vehicle Recycling Partnership (VRP) and the American Plastics Council (APC), is working to develop technology for recycling materials from shredder residue. Several other organizations worldwide are also working on developing technology for recycling shredder residue. Without a commercially viable shredder industry, our nation may face greater environmental challenges and a decreased supply of quality scrap and be forced to turn to primary ores for the production of finished metals. This document presents a review of the state of the art in shredder residue recycling. Available technologies and emerging technologies for the recycling of materials from shredder residue are discussed
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Materials recovery from shredder residues
Each year, about five (5) million ton of shredder residues are landfilled in the US. Similar quantities are landfilled in Europe and the Pacific Rim. Landfilling of these residues results in a cost to the existing recycling industry and also represents a loss of material resources that are otherwise recyclable. In this paper, the authors outline the resources recoverable from typical shredder residues and describe technology that they have developed to recover these resources
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Thermal decomposition of PMC for fiber recovery
This paper describes efforts by Argonne National Laboratory to develop a process to recover carbon fibers from polymer matrix composite (PMC) materials. The polymer material in the matrix maybe a thermoplastic or a thermoset. Samples of panels containing PMC fibers were obtained and used in the bench-scale testing program. The authors tested three different methods for recovering these PMC fibers: thermal treatment, chemical degradation, and cryogenic methods (thermal shock treatment). The first two methods were effective in separating the carbon fibers from the polymeric substrate; the third method was not satisfactory. Carbon fibers separated from the polymer substrate using the thermal treatment method were submitted to Oak Ridge National Laboratory for analysis and evaluation. The results indicated that the carbon fibers had been cleanly separated from the polymer matrix. Their intrinsic density was 1.8473 g/cm{sup 3} and their electrical resistivity was 0.001847 ohm-cm, compared to an intrinsic density of 1.75--1.9 gm/cm{sup 3} and an electrical resistivity of 0.0002--0.002 ohm-cm for virgin fibers produced from polyacrylonitrile (PAN). Although they were not sure that the samples they processed were originally produced from PAN, they used the PAN fibers for comparison. It was also demonstrated that the surface of the recovered fibers could be reactivated to energy levels equivalent to those of reactivated virgin fibers from PAN. A comparison of the mechanical properties of the recovered fibers (without surface treatment) with those of surface-treated virgin fibers from PAN revealed that the ultimate tensile strength and the elongation at brake values are about 1/3 the values for the virgin fibers. The modulus for the recycled fibers (31.4 million pounds per square inch [psi]) was about the same as that for the virgin PAN fibers (31.2 million psi). The reason for the lower tensile strength and elongation is not clear; the authors plan to investigate it further as part of the process improvement study that is now underway. Process economics appear very promising, and a payback of less than two years is likely
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Progress in recycling of automobile shredder residue
At Argonne National Laboratory, we have been developing a potentially economical process to recycle automobile shredder residue (ASR). We identified three potentially marketable materials that can be recovered from ASR and developed technologies to recover and upgrade these materials. We build and tested a field-demonstration plant for recycling polyurethane foam and produced about 2000 lb of recycled foam. Several 300-lb samples were sent for evaluation and were found to be of marketable quality. We are also preparing for a large-scale test in which about 200 tons of ASR-derived fines will be used as a raw material in cement making. A major cement company has evaluated small samples of fines prepared in the laboratory and found that they meet its requirements as a substitute for iron ore or mill scale. We also produced about 50 lb of recycled acrylonitrile butadiene styrene (ABS) from obsolete automobiles and found that it has properties that could be readily upgraded to meet the specifications of the automotive industry. In this paper, we briefly discuss the process as a whole and summarize the results obtained from the field work on foam and fines recycling
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Recovery and separation of high-value plastics from discarded household appliances
Argonne National Laboratory is conducting research to develop a cost- effective and environmentally acceptable process for the separation of high-value plastics from discarded household appliances. The process under development has separated individual high purity (greater than 99.5%) acrylonitrile-butadiene-styrene (ABS) and high- impact polystyrene (HIPS) from commingled plastics generated by appliance-shredding and metal-recovery operations. The process consists of size-reduction steps for the commingled plastics, followed by a series of gravity-separation techniques to separate plastic materials of different densities. Individual plastics of similar densities, such as ABS and HIPS, are further separated by using a chemical solution. By controlling the surface tension, the density, and the temperature of the chemical solution we are able to selectively float/separate plastics that have different surface energies. This separation technique has proven to be highly effective in recovering high-purity plastics materials from discarded household appliances. A conceptual design of a continuous process to recover high-value plastics from discarded appliances is also discussed. In addition to plastics separation research, Argonne National Laboratory is conducting research to develop cost-effective techniques for improving the mechanical properties of plastics recovered from appliances
End-of-life vehicle recycling : state of the art of resource recovery from shredder residue.
Each year, more than 25 million vehicles reach the end of their service life throughout the world, and this number is rising rapidly because the number of vehicles on the roads is rapidly increasing. In the United States, more than 95% of the 10-15 million scrapped vehicles annually enter a comprehensive recycling infrastructure that includes auto parts recyclers/dismantlers, remanufacturers, and material recyclers (shredders). Today, over 75% of automotive materials, primarily the metals, are profitably recycled via (1) parts reuse and parts and components remanufacturing and (2) ultimately by the scrap processing (shredding) industry. The process by which the scrap processors recover metal scrap from automobiles involves shredding the obsolete automobile hulks, along with other obsolete metal-containing products (such as white goods, industrial scrap, and demolition debris), and recovering the metals from the shredded material. The single largest source of recycled ferrous scrap for the iron and steel industry is obsolete automobiles. The non-metallic fraction that remains after the metals are recovered from the shredded materials - commonly called shredder residue - constitutes about 25% of the weight of the vehicle, and it is disposed of in landfills. This practice is not environmentally friendly, wastes valuable resources, and may become uneconomical. Therefore, it is not sustainable. Over the past 15-20 years, a significant amount of research and development has been undertaken to enhance the recycle rate of end-of-life vehicles, including enhancing dismantling techniques and improving remanufacturing operations. However, most of the effort has been focused on developing technology to separate and recover non-metallic materials, such as polymers, from shredder residue. To make future vehicles more energy efficient, more lightweighting materials - primarily polymers, polymer composites, high-strength steels, and aluminum - will be used in manufacturing these vehicles. Many of these materials increase the percentage of shredder residue that must be disposed of, compared with the percentage of metals that are recovered. In addition, the number of hybrid vehicles and electric vehicles on the road is rapidly increasing. This trend will also introduce new materials for disposal at the end of their useful lives, including batteries. Therefore, as the complexity of automotive materials and systems increases, new technologies will be required to sustain and maximize the ultimate recycling of these materials and systems. Argonne National Laboratory (Argonne), the Vehicle Recycling Partnership, LLC. (VRP) of the United States Council for Automotive Research, LLC. (USCAR), and the American Chemistry Council-Plastics Division (ACC-PD) are working to develop technology for recovering materials from end-of-life vehicles, including separating and recovering polymers and residual metals from shredder residue. Several other organizations worldwide are also working on developing technology for recycling materials from shredder residue. Without a commercially viable shredder industry, our nation and the world will most likely face greater environmental challenges and a decreased supply of quality scrap, and thereby be forced to turn to primary ores for the production of finished metals. This will result in increased energy consumption and increased damage to the environment, including increased greenhouse gas emissions. The recycling of polymers, other organics, and residual metals in shredder residue saves the equivalent of over 23 million barrels of oil annually. This results in a 12-million-ton reduction in greenhouse gas emissions. This document presents a review of the state-of-the-art in the recycling of automotive materials
Finishing the euchromatic sequence of the human genome
The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead
Retrieval of passages for information reduction
Information Retrieval (IR) typically retrieves entire documents in response to a user\u27s information need. However, many times a user would prefer to examine smaller portions of a document. One example of this is when building a frame-based representation of a text. The user would like to read all and only those portions of the text that are about predefined important features. This research addresses the problem of automatically locating text about these features, where the important features are those defined for use by a case-based reasoning (CBR) system in the form of features and values or slots and fillers. To locate important text pieces we gathered a small set of excerpts , textual segments, when creating the original case-base representations. Each segment contains the local context for a particular feature within a document. We used these excerpts to generate queries that retrieve relevant passages. By locating passages for display to the user, we winnow a text down to sets of several sentences, greatly reducing the time and effort expended searching through each text for important features