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  Plasma Power

 Plasma Power
Lou Circeo, right, director of plasma research programs at the Georgia Tech Research Institute, and Bob Newsom, senior research technologist show samples of soil the plasma arc torch has reduced to glass.



By Kimberly Link-Wills
Think of a plasma arc torch as a man-made continuous lightning bolt. Hotter than the surface of the sun, plasma is a tool so powerful that it can melt or vaporize contaminated soil, diseased animals, piles of garbage — and leave behind only pebbles of glass.

Plasma technology isn’t new. NASA developed it in the 1960s to test heat shields’ ability to withstand spacecraft re-entry into Earth’s atmosphere. With temperatures exceeding 7,000 degrees Centigrade — three times hotter than fossil fuels — the plasma arc torch’s potential is incredible.

It is possible to transform a landfill heaped with stinking rubbish into a glass boulder. Because all known hazardous and toxic chemical and biological agents are destroyed and reduced to their elemental components, it is possible to prevent radionuclides from leaching into the groundwater around Chernobyl and thus reduce harmful exposures to the surrounding populace. It is possible to supply electricity to our homes with gases captured from garbage, old tires and junkyard cars.

Lou Circeo’s hair has grayed as he has waited for the plasma arc torch to ignite wide-swept changes in the way Americans dispose of their garbage, fuel their factories and illuminate their homes.

Circeo, director of plasma research programs at the Georgia Tech Research Institute, received his undergraduate degree from West Point and his master’s and PhD from Iowa State

He began working with plasma technology in the early 1970s and came to Georgia Tech in 1987 as the founding director of the Construction Research Center in the College of Architecture, where he used the torch to harden and vitrify unstable soil into a rock foundation on building sites.

"You could build a World Trade Center complex on this vitrified soil," Circeo said in an Atlanta Journal-Constitution article at the time. "It’s much better than concrete. Hell, concrete may go out of style once we’re finished."

Tech launched its plasma research facility, with Circeo as its head, in 1991. It is arguably the largest university-based research program for plasma processing of waste materials in the country.

Circeo has watched as other countries have picked up the technology. "We developed the torches, we developed the ideas, but the Japanese and the Europeans are the ones who are commercializing it," he says.

"In Japan, they’re using their system for disposal of municipal solid waste and automobile shredder residue, what’s left after they recycle all the metals and everything else they can. They’re running out of landfill space in Japan. That’s why Hitachi Metals was so interested in doing this.

"Anything they don’t want is put into the hopper and it goes through a slight grinding process. Then it’s squeezed into a bale that’s pushed into the furnace. The only thing that comes out of there is a molten stream — no ashes, no cinders, just a molten stream. That’s put into water. What they end up with, instead of a big block of hard rock, is a sand-like material. The fuel gases that come off — mainly hydrogen and carbon monoxide — are sent into a secondary combustion system. The hot gases are then mixed with water to form steam, which goes up and runs a turbine to produce electricity. After a treatment process, the gaseous emissions are essentially carbon dioxide by the time they get up in the stack," Circeo explains.

He says Japan’s 25-tons-per-day facility has been so successful that a 200-tons-per-day plant is in the works. He says five facilities that size could probably get rid of most of the city of Atlanta’s garbage.

Tech hosted what Circeo says was one of the largest plasma waste disposal technology conferences in the world in 1995. "We had something like 90 papers and people from 13 different countries here."

Reaction to plasma technology from the general population in the United States, however, hasn’t exactly been glowing. "You asked me why people aren’t using this," Circeo says, pointing to a newspaper headline. "This is a typical case study of how difficult it is to get new technologies introduced."

In 1998, the Lumpkin County commissioner came to the Tech lab for a plasma torch demonstration. He and a local businessman hoped to build the first U.S. commercial plasma melting facility for municipal solid waste outside Dahlonega in the north Georgia county. Political opposition and Lumpkin County residents wary of a torch hotter than the sun and garbage being brought into their county ultimately led to the Dahlonega City Council’s defeat of the proposed plasma plant.

"It got so bad they took out full-page ads in the newspapers there — ‘save your home, save our county from the plasma torch,’" Circeo says.

"It got so heated they had town meetings. It actually made the Wall Street Journal," which quoted a Dahlonega councilman as saying, "The people who are trying to sell this are snake-oil salesmen."

Circeo pitches plasma to whomever he can, whenever he can. He powers up the torch for lawmakers, federal funding committees and the media. He hands those treated to an up-close demonstration of the plasma torch protective face shields and earplugs. An overhead catwalk allows visitors to peer down inside a barrel, where soil is transformed into a boiling liquid within minutes by the 100-kilowatt torch, only 3 inches in diameter.

Circeo says a company has expressed interest in working with Tech to create a mobile plasma torch system. "We could go to a place like the collapsed World Trade Center and this technology would rapidly melt through girders and concrete. If somebody’s stuck under a concrete or steel beam, this will cut it in just a few minutes."

Like media coverage, funding has not remained steady over the years. "The problem is that our funding sources are hot and cold. We get champions. The champions retire or get reassigned, and suddenly funding priorities get shifted to other projects. We’ve had lean years. That’s the name of the game in technology research," shrugs Circeo.

With fears of bioterrorism heightened since Sept. 11, the plasma torch may yet draw big-dollar research support.

"We’ve got a couple of proposals in on how plasma can be used. One of them is to get rid of diseased animals, large quantities of them, up to several tons an hour. We can feed the carcasses into a furnace to get rid of animals contaminated with mad-cow disease. If there was a bunch of cows infected with anthrax, this would get rid of them very, very quickly and very safely," Circeo says.

"The other proposal is to decontaminate large areas that have biological contamination or chemical agent contamination because this technology will destroy anything. This is why plasma is so important. All the hazardous and toxic compounds are broken down to their basic elements. These elements recombine into simple acid gases that are easy to neutralize," he says.

"The Department of Energy is especially interested because this technology will readily remediate their most ‘difficult to treat’ contaminants and immobilize residual radionuclides and heavy metals in the most ‘difficult to melt’ soils and rocks," Circeo says. "The U.S. Navy has selected plasma as a way to get rid of shipboard wastes for their big ships because they can’t throw most of it overboard anymore." A prototype system built for aircraft carriers is undergoing testing.

©2002 Georgia Tech Alumni Association

 
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