The US. foundry industry is about to be reinvented to maximize pollution prevention. JEANNE TROMBLY
n a visit to McClellan Air Force Base in Sacramento, CA,in early 1993, Dennis Schuetzle, a Ford Motor Company manager, mulled over how the Big Three auto companies could help one of their major suppliers, the metal-casting industry, clean up its act. One of the country’s oldest manufacturing sectors-“preceding the Revolution,” boasts the American Foundrymen’s Societyfoundries have incorporated few major environmental improvements in the past century. Consequently, casting plants face formidable challenges as the 1990 Clean Air Act Amendments (CAAA) require lower emissions by the year 2000. “Castingis one of the dirtiest processes of any industry,” says Schuetzle. “You typically find foundries in areas with noticeably high levels of haze, smoke, and bad odors.” On a follow-up trip the next month, Schuetzle and Jeny Rogers, a section manager at General Motors, were invited by Leo Dobitz, division chief of manufachuing services for Mcclellan Air Force Base, to tour the base’s foundry. That tour ended with a series of handshakes that led to a $40 million pact between the federal government and the private sector to completely reinvent the foundry industry. The end result is expected to be the “foundryof the future”with near-zero emissions. The Cas- Emission Reduction Program (CERP) includes as participants the U.S. Air Force Advanced ManufaauringTechnologyCenter at Mccldan and the US. auto company coalition called the Environmental Research Consortium,a committeeof the US. Council for Automotive Research. The consortium includes Chrysler corporation, Ford Motor Company, General Motors Corporation, and Navistar International Corporation. The Air Force and the consortium have joined as an operating entity under an umbrella organization, the California Office of Research Technology Application. EPA, the California Air Resources Board, and the American Foundrymen’s So7 6 A . VOL. 29. NO. 2 . 1 9 9 5 1 ENVIRONMENTAL SCIENCE &TECHNOLOGY
The toxic emissions pmduced when hot lnatal h i a sand mold and vaporizes the organic binder are one target of a $40 million program to develop foundries with naar-zaro emissions.
ciety are also participating in the project. The fiveyear project will receive $40 million of federal funding through the Department of Defense, the first
installmentofwhichwasappmvedbyCongressin 1994. This project marks another “dual-use” pact in which both the government and the private sector apply resources in tandem and devise outcomes that jointly benefit each program. The CERP team is devising new measurement processes for metalcasting manufacturing and emissions in order to meet 0013-936w9510929-76/09.00fl
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environmental regulations, stop the industry’s flight overseas, and possibly even develop new environmental technologies for export. The stakes are high for the Big Three auto companies. Because U.S. metal-casting output has eroded by 25% the U.S. auto companies’ reliance on foreign foundries has grown at an uncomfortable rate. Currently, more than 40% of U S . casting products are imported, and the figure is growing. The US. metal-casting industry has been rapidly losing market share to foreign companies. According to the American Foundrymenk Society, more than 1000 foundries have shut down or moved offshore in the past decade because of the costs of regulatory compliance. The 3100 or so metal-casting facilities that remain and their supporting businesses represent a 530 billion industry and 300,000 U.S. jobs. l)?ically operated as small family-owned businesses, 80% of U S . metal-casting shops have fewer than 100 employees. Even though each major auto manufacturer owns and operates at least one major foundry, small shops depend on the automobile and transportation equipment industries to purchase 60% of all castings produced. Another 10%of castings are produced solely for military application. The remaining share serves just about every other US. manufacturing sector. “What we’re doing will have a big impact on the entire metal-casting industry; frankly, they’re counting on it,” said Mark Bindbeutel, pollution prevention manager at Chrysler Corporation.
Emissions inventory lacking The challenge is daunting. Although they face strict air quality control standards, foundries have been unable to incorporate pollution control systems, mainly because the industry has never before conducted a comprehensive inventory of all its pollutants. “Before we can solve our environmental problems, we first have to better define them,” said Rogers. lbenty years ago, the Big Three agreed on the need to practically overhaul their metal-casting operations and install emissions control technology, hut their research and development efforts stalled because of lack of resources. Recent regulatory developments, however, have renewed the auto industry’s interest in tackling its manufacturing environmental problems. Combinations ofnew or improved methods, materials, processes, and end product design changes-basic pollution prevention strategies-are now being pursued. McClellan Air Force Base was also facing a few problems of its own. It had been on the 1993 list of base closures as a result of defense expenditure cuts. But, equipped with one of the country’s most advanced metal materials manufacturing and testing facilities, McClellan was able to find a new role working with the private sector to help revitalize a basic U S . industry Project participants expect to use some of the Air Force’s advanced technology, which includes a wealth of nondestructive inspection equipment, such as real-time 3D X-ray fluoroscopy and neutron radiography. By using neuVOL. 29. NO. 2,1995 I ENVIRONMENTAL SCIENCE 5 TECHNOLOGY rn 7 7 A
trons instead of X-rays to test the structural integrity of materials, the participants can test new composites and binders. Just months after the CERP pact was signed, McClellan was pulled off a long list of base closures. Because iron foundries are major sources of hazardous air pollutants (HAPS)that are regulated under the 1990 CAAA, they must incorporate emission reductions by 2000. Some of the industry’smost common HAPS are thought to be aromatic cornpounds, such as toluene, xylene, phenol, and naphthalene. “Before 1990, we were facing RCRA regulations for solid waste and water discharge regulations that started in 1982,”said Gary Mosher, director of environmental affairs for the American Foundrymen’s Society. “Now the focus is on emissions.”
Baseline measurements study Facing serious air emissions reduction goals, the team is conducting a characterization study to assess current sources of pollutants and establish a chemically speciated baseline. For years foundries have tried to quantify the emissions coming from production lines and analyze which pollutants are emitted at each point in the manufacturing process. “There appear to be gaps in existing data, or data that don’t correspond with earlier test results,” says Bill Walden, site program manager for CERP. “The idea is to simply validate that something is or is not there.” “Most of the work that has been conducted has concentrated on criteria pollutants and particulate matter,” says Rogers. He thinks that some of the most common HAPS in the metal-casting process are aromatic compounds. The compounds thought to be especially problematic come out of the organic binder, the material that holds together the mold (made up of sand, coal, and clay) long enough for the mold to form. When the hot metal hits the sand mold, the binders vaporize to form toxic emissions. To conduct the baseline study, which has just started, a government-based group of stack emissions analysts have been trained and sent out into the field. Up to 18 foundries across the country, both those run by auto companies and those run by nonauto companies, are participating voluntarily as sites of emissions testing. From the initial steps of scrap metal pretreatment to the latter stages of metal pouring, molding, and cooling, each step of the metalcasting process is being examined to evaluate the emissions associated with that step. EPA is also working with these teams to design and conduct the characterization study. “Frankly, we’re working with the EPA to conduct the field testing that they would otherwise have to do,” said Walden. When complete, the data will contribute to the development of Maximum Achievable Control Technology that EPA will use to set new emission standards for Clean Air Act compliance by the foundry industry. Once the characterization study is complete, the project’sfocus will shift back to McClellan early next year when a small prototype iron auto foundry built especially for the project will be completed. This foundry will incorporate unprecedented configurations of equipment and materials that will allow 78 A
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project personnel to make quantitative measurements of emissions from each step in the casting process. Six technology teams will be responsible for developing new ideas, theories, and research proposals to test new systems at the pilot foundry. By pouring sample casts of four-cylinder engine blocks and capturing and monitoring the emissions at each stage of production, these teams will be able to measure the specific impacts of the new processes.
Preventing solid waste In addition to reducing emissions,the project will also investigate new approaches to reducing the industry’s unique source of hazardous solid waste, “green sand,” which is used to make the expendable mold. Although the industry captures and reuses most of its sand up to 10 times, 4% of the sand is considered hazardous waste. Even though the CERP program will attempt to find cleaner, potentially inorganic binders, Bindbeutel’s preference would be to eliminate the use of sand in favor of a permanent mold made from foam or metal. “In order to stay competitive, we have to get closer to the source of pollution. U.S. industry is good at managing waste, but we should instead be trying to prevent it from the onset,” says Bindbeutel. Once the pilot iron foundry is in operation, the project will turn its attention to aluminum casting, a manufacturing area that is growing as transportation trends move toward lightweight vehicles. “The automotive industry predicts that by the year 2000, half of all finished casted automotive units will be aluminum,” reports Walden. Although experts from industry and academia have been involved with CERP since its inception, Walden expects their involvement to enter a new phase in the project’s third year. Some chemical cornpanies have already expressed an interest in testing new binders. “The chemical companies have needed a place to test new materials, but they can’t exactly go to an auto foundry and interrupt production,” says Dobitz. Along with the rewards of dual-use technology pacts come potential complications regarding ownership and licensing of any new processes that result. The Environmental Research Consortium expects to own any new patents and make the new technology available to companies. Likewise, the Department of Defense will have access to all new technology, and McClellan will end up with the country’s most advanced foundry. The project team has not specified how existing independent foundries will incorporate the new technology developed by the project. Because the majority of U.S. foundries are small- to medium-sized facilities, it is not clear how quickly individual firms will be able to incorporate any expensive state-ofthe-art processes that emerge. But the project is certain to produce a thoroughly rethought industry customized for pollution prevention. “Whether vapor, liquid or solid, we are going to try to create a closed loop system so there is no waste,” says Dobitz. Jeanne Trombly is a freelance science writer based in San Francisco. She has written previously for ES&T on electrochemical remediation.
