FY2004 OSWER Innovation Pilot Results Fact Sheet oEPA Using Auto Shredder Residue as Cement Manufacturing Component The Environmental Protection Agency's Office of Solid Waste and Emergency Response initiated a series of innovative pilot projects to test ideas and strategies for improved environmental and public health results. This series of fact sheets highlights the innovative approaches, results, and environmental and economic benefits from the pilot projects that may be replicated across various sectors, industries, communities, and regions. PROJECT DESCRIPTION/INNOVATION EPA awarded a grant to the California Office of Pollution Prevention and Technology Development to study the feasibility of using automobile shredder residue (ASR) as a supplemental fuel and mineral feedstock (the raw material required for production) in cement kilns, to both fuel the kilns and manufacture cement, The main barrier to the recovery of energy value from ASR had been the perception that it was too contaminated, had a low heating value, and the variability of its physical nature, However, cost-effective methods to separate ASR into energy and mineral rich materials facilitated its use for both fuel and cement production. This project identified the feedstock quality parameters and the mechanical means necessary to process ASR into material suitable for both fuel and cement production, This project represented the first ASR tests for these uses in the United States, BACKGROUND Auto shredder residue (ASR) is comprised of materials remaining after a vehicle has been shredded and removed of reusable parts and metals. These materials include plastics, rubber, foam, residual metal pieces, paper, fabric, glass, sand and dirt. According to a 2004 study, more than three million tons of ASR were generated in the U.S. annually, and nearly all was landfilled. ASR could potentially be used as a supplement to conventional fuel in cement kilns. Studies show that cement kilns use a wide variety of different fuels without compromising cement product quality, plant operations or emissions. Numerous studies have illustrated the successful use of alternative fuels and minerals in cement manufacturing, the resulting benefits of energy and raw materials savings, the incorporation of residual ash into the cement product, and the destruction of organic constituents in the fuel. However, unprocessed ASR has poor fuel characteristics, due to its high ash content; the presence of contaminants, including heavy metals, chlorine, and polychlorinated biphenyls (PCBs); • About one million tons of ASR could be recovered for fuel in the U.S., which would comprise approximately six percent of the U.S. cement manufacturing industry's energy consumption and save $50 million annually (assuming $50 per ton of coal). • One million tons of avoided landfilling would amount to more than $20 million savings annually. • Use of one million tons of ASR for fuel would result in reduced C02 emissions and the conservation of approximately one million tons of coal annually, and its composition of approximately 20 to 50 percent incombustibles. Prior to use as a fuel, ASR required separation and processing to isolate combustible materials with low ash content and low contaminant concentrations. Since many reuse and recycling options may not be environmentally beneficial or cost effective, there was a need for further study. PROJECT SUMMARY In 2004, the California Department of Toxic Substances Control (DTSC), in cooperation with the University of California at Berkeley and EPA's Office of Resource Conservation and Recovery (ORCR), conducted a study to identify the feedstock quality parameters needed to satisfy kiln operators and assess the mechanical means necessary to process ASR into material acceptable as coal and mineral feedstocks for cement production. To test this concept, this study investigated cost-effective methods for separating and processing the ASR stream to make it a suitable fuel for cement kilns. DTSC conducted laboratory tests to assess the ASR characteristics, including physical parameters and fuel characteristics, as well as beneficial elements and contaminant concentrations of PCBs and other contaminants, Based on the results, DTSC worked with kiln operators to determine ------- the considerations for supplemental fuel and mineral additives. DTSC then conducted field tests to demonstrate separation techniques to recover valued streams. Physical and chemical laboratory tests determined the energy, mineral and contaminant content of the processed streams and validated conformance with kiln specifications. DTSC estimated operating costs for a full scale separation system and compared it to the costs of landfilling ASR. In addition, EPA worked with DTSC to ensure any environmental issues were addressed including the collection of data on mercury, cadmium, lead and PCBs. RESULTS The physical and chemical test results allowed kiln operators to assess the limitations of ASR as a fuel or mineral substitute. The study showed beneficial mineral content (namely silicon) was less than expected. After discussions with shredder operators, it was determined that substantial removal of glass occurred at the dismantling yards before automobiles reached the shredding facility. As a result, recovery of ASR for mineral content was not studied further. The demonstrated separation method achieved a mixture of ASR that represented 30 percent of the original mixture and had a heating value of approximately 13,240 Btu per pound, which was higher than that of most coal types. Applying the results of this study to the U.S. would result in about one million tons of ASR recoverable for fuel. Using this amount for cement kilns could save the cement manufacturing industry $50 million annually through reduced energy cost (assuming $50 per ton of coal). It could also save auto shredding operations $20 million annually in avoided landfilling costs. While the costs of processing the ASR for use in cement kilns would also amount to $20 million annually, auto shredding operations could also generate $20 million annually in revenue from the sale of copper (based on 13,000 tons of copper alone). If the estimated one million tons of recovered ASR was used instead of coal in U.S. cement kilns, it would potentially provide six percent of the cement industry's energy needs. It would also result in reduced C02 emissions and the conservation of approximately one million tons of coal annually. Additionally, potential impacts of landfill leachate contaminated with ASR constituents would be avoided by diverting ASR from landfills. The study further found that additional financial and environmental benefits could be realized by providing incentives for ASR recovery, and by supporting markets for ASR derived products. Lead: California Office of Pollution Prevention and Technology Development Sponsor: U.S. EPA Office of Resource Conservation and Recovery Other Partners: • Hugo Neu-Proler Co. • Mitsubishi Cement Company • University of California at Berkeley OSWER Innovation Projects: www.epa.gov/oswer/iwg/pilots/ EPA's Recycling Automotive Parts: www.epa.gov/osw/conserve/materials/auto.htm 2010 UPDATE DTSC and EPA continue to research the benefits of using ASR as a supplemental fuel and mineral feedstock in cement kilns. In 2006, DTSC authored and EPA co-funded the report, Evaluation of Shredder Residue as Cement Manufacturing Feedstock, and in 2008 EPA developed the draft report, Cement Sector Trends in Beneficial Use of Alternative Fuels and Raw Materials. In March 2010, these research efforts were used in support of EPA's Resource Conservation and Recovery Act (RCRA) proposed rulemaking: Identification of Nonhazardous Secondary Materials That Are Solid Waste. A United States Environmental Protection m m Agency OSWER Innovation Pilot Results Fact Sheet Using Auto Shredder Residue as Cement Manufacturing Component — August 2010 ------- |