Roanoke Times
Copyright (c) 1995, Landmark Communications, Inc.
DATE: TUESDAY, November 1, 1994 TAG: 9411010077
SECTION: BUSINESS PAGE: C-8 EDITION: METRO
SOURCE: Associated Press
DATELINE: WARREN, MICH. LENGTH: Medium
Three-fourths of the material in a scrapped car is reused or recycled. What's left is called ``car fluff,'' a grimy goulash of plastic, glass, rubber, rust and fluid that ends up in landfills.
Scientists at General Motors Corp., using a heat process as old as charcoal-making, are trying to prevent that by turning fluff into gaseous and oil fuels, and a black powder residue that can be used to make car parts, stronger cement, roofing shingles and more.
``This oil can be burned just like a fuel oil,'' Kedar B. Agarwal said Friday as he showed off a small jar of brown, syrupy ``pyro'' oil.
Agarwal, a senior project engineer at GM's manufacturing technology center, was demonstrating a pyrolysis unit, the device that produced the oil and gave it its name.
Pyrolysis is chemical decomposition by heat, without the burning that occurs when oxygen is present. It's been used through the ages, to make charcoal from wood or coal, to make synthetic oil from rubbish during World War II, to destroy medical wastes in the 1990s.
GM hopes to find a way it can be used to economically deal with the leftovers from the 11 million cars and trucks junked each year in this country.
``We want to avoid the landfill,'' Agarwal said. ``Pyrolysis is the only process, I think, that is environmentally safe and economical.''
The development could be good news for Roanoke Electric Steel, which recycles cars at its Shredded Products facility in Bedford County.
After a "fluff fire" there five years ago, the company decided to move to Franklin County, where it has built a new landfill to take up to 50 tons of fluff a day. Shredded Products plans to move to the costly facility later this month.
GM's pyrolysis unit is a big, metal oven-like box about 5 feet wide by 3 feet tall with tubes running in and out.
The fluff is heated to about 1,400 degrees. That's hot, but below temperatures used for incineration.
Nitrogen is pumped in through one of the tubes, pushing out the oxygen which could cause burning and prevent the pyrolysis process. Other tubes leading from the box expel the products.
A recent test processed 20 tons of fluff. What was left was 26 percent gas, 21 percent oil, 10 percent water and 43 percent powdery black residue.
GM scientists say the gas alone could provide energy to operate the pyrolysis unit.
Burning pyro gas produces more energy than natural gas, and what goes up the chimney meets Environmental Protection Agency emissions standards, said Larry Daniels, a GM engineer who works with the Vehicle Recycling Partnership of the U.S. Council for Automotive Research, a consortium of the Big Three automakers.
The black pyro residue occupies about one-tenth the space of the fluff that produced it, so even if it were dumped it would ease solid-waste concerns. But why dump it?
Researchers are finding that it can be used in automotive composites for plastic bumpers and body panels. Mixed with cement, it makes a mortar that doesn't expand. Other uses include roof shingles and asphalt.
At the laboratory level, the pyrolysis system shows promise. Irv Poston, manager of polymer composites at GM's technical center, said the goal now is to develop a unit that can process two tons of fluff per hour, and to find an existing processor to test it.
``We're not sure how this will scale up,'' Poston said.
Daniels said a typical shredder, which pulverizes what's left of a car after removal of the pieces that have value, can produce 36 tons of fluff per hour. ``We think multiple two-ton [pyrolysis] units might make sense,'' he said.
GM wouldn't disclose how much it's spending on the pyrolysis research, but said the goal is a process that could be a money maker for someone.
Poston said people in the scrap vehicle recycling and resale business are interested.
``Some who are burying this fluff now say they may mine it later to get the energy value out of it.''
Staff writer Cathryn McCue contributed to this story.
by CNB