IN THE LAB
- By Jim DiPeso
- Dec 01, 2000
Rewarded for reuse
Ten million tons of metal are recovered annually from disposed automobiles, with five million tons of nonmetallic scrap left over afterward. Of these five million tons, five percent of the weight - 30 percent of the volume - is dirty foam that contains entrained automotive fluids, dirt and small pieces of glass and metals. Researchers at Argonne National laboratory (ANL) developed a process that separates and cleans the foam so it can be reused for carpet pads, furniture cushions and automobile soundproofing material.ANL has won an R&D 100 Award given annually by R&D Magazine to the 100 most significant technical products of the year. ANL's inventive process to recover and clean flexible polyurethane foam keeps approximately 300 million pounds of automobile scrap from landfills while saving about 12 trillion British thermal unit (Btu) of energy annually in the United States.
Every year, auto shredders generate three to five million tons of waste, commonly known as automotive shredder residue (ASR).The Argonne technique for recycling ASR begins by loading chunks of mostly foam on a conveyor that runs the material in a rotating cylinder through screens and slots. That process separates dirt, plastic, metal, wood and residues from foam.
ASR is separated into several fractions: iron-oxide-rich "fines," which may be used by the cement industry as a source of iron oxide; a plastics-rich stream, from which Argonne dissolves and recovers heat-formed plastics (thermoplastics); and polyurethane foam, which is separated and cleaned.
The foam goes on a conveyor belt that is fed into a 50-foot washer-dryer system that uses compression, hot water, detergent and 300 degree Farenheit air to clean and dry the foam.
The solvent used in the process is regenerated and continuously recycled. If fines, foam and plastics are recycled, as much as 75 percent of landfill waste could be eliminated.
The system transforms oily chunks of foam and residue into bales of clean, dry, yellow foam in about 35 minutes. Foam manufacturers shred the foam, mix it with chemicals used in producing the polyurethane foam and compress the material in logs that are shaved into strips for installation as carpet padding, furniture cushions or other uses.
After signing a licensing agreement with Argonne last year, a Belgium company is building the device for use in Europe, where the European Union is requiring that waste from scrapped automobiles be reduced by 40 percent by 2005.
For more information visit Argonne National Laboratory at www.anl.gov.
The big picture
The Millennium Ecosystem Assessment is coming to ecosystems everywhere early next year. The four-year, $20 million effort will bring ecologists and social scientists together to gather and analyze data on the condition of the world's ecosystems and to project environmental trends. Will Mother Nature be able to provide food and clean water to children of the future? How are we to handle pollution and deforestation all at once?
The assessment is a "more holistic" approach than previous assessments, says Walter Reid, former vice president of programs at the World Resources Institute (WRI) in Washington, D.C.
The Millennium Ecosystem Assessment is funded by the United Nations and the World Bank and aims to generate global and local information assessing remedies for environmental issues. Additionally, the project will pursue regional assessments to help policy-makers solve problems and avoid future disasters. Climate scientists used a similar approach in the Intergovernmental Panel on Climate Control (IPCC) begun in 1988.
"The challenge the assessment faces right now is that its trying to do several extremely difficult things all at the same time," Harvard environmental policy expert William Clark said. These include evaluating ecosystem health while supplying data to implement treaties and selling the message that ecosystems have economic value.
WRI has conducted a Pilot Analysis of Global Ecosystems (PAGE) to be released as part of their biannual World Resources 2000-01 report. Reid said PAGE was "proof of a concept that proved data and information are available at a global scale." Scientists are eager to proceed in more depth than before concerning global forest cover, natural soil erosion as well as comparative studies such as growing more crops by converting forests to farmland versus using more fertilizers and pesticides.
Like the IPCC, it is anticipated that teams will be made up of 500 authors and 2000 reviewers and the assessment would be primarily a literature synthesis. However, there is hope for new data such as high-resolution Landsat 7 images of global land cover. Teams can be expected to develop two dozen indicators for ecosystem health, such as the crop maps that were developed as part of PAGE. "This is a new era for ecologists," ecologist Stephen Carpenter of the University of Wisconsin, Madison said.
Organizers want to tailor the information to the needs of those implementing international environmental agreements. "There are very few examples as integrated as what the Millenium Assessment envisions," said Carpenter.
The assessment will offer advice to policy makers and if it is done properly, the result will be a most complete data system on world ecosystems available.
For more information, visit www.sciencemag.org.
Lisa Rademakers is assistant editor of Environmental Protection
This article originally appeared in the 12/01/2000 issue of Environmental Protection.