SUNDAY, Sept. 9, 2001 (HealthDayNews) -- A new twist on an old technology cleans pollutants from the emissions of coal-fired power plants and other industrial smokestacks. Better still, it does it more efficiently and cheaply than currently possible, say the scientists who developed the technology.
At least that's the case in laboratory settings. The true test of the new technology will come once it has been installed and observed in operating power plants.
Known as a "membrane electrostatic precipitator," the device is a more effective version of one that's been used for about a century, says David Bayless, associate professor of mechanical engineering at Ohio University's Russ College of Engineering and Technology.
The design created by Bayless and his colleagues uses 1- to 3-millimeter-thick membranes woven from carbon, silicon and similar fiber-based materials to capture tiny air pollutants and toxic heavy metals.
When coal is burned for fuel, it produces exhaust thick with fly ash, which contains trace metals such as arsenic -- a health hazard to humans. But as the fly ash moves up the smokestacks, the new electrostatic precipitators would collect the particles before they could be released into the air.
Old model electrostatic precipitators use heavy, expensive steel plates to attract the particles. The new membrane versions would be more efficient, less expensive, 10 to 20 times lighter and not susceptible to corrosion, Bayless says.
The steel models also are cleaned of ash by striking them with a hammer device, which actually sends some of the pollutants into the air. The membrane precipitators can be cleaned with water, he says.
Bayless says laboratory tests showed the membrane devices collected 30 percent more pollutants than their steel counterparts.
"We can say it performed well in the lab tests, but there's a big difference in how it behaves in a large-scale setting," Bayless says. "Until we get it onto a real power plant, I don't know with any confidence just how much better it is than what we have now."
The technology has been licensed by Southern Environmental Inc., which is talking to a number of power companies about testing it, Bayless says.
While the motivation for developing the membrane devices was to clean emissions from coal-fired power plants, Bayless says the devices could be used in many different industrial settings, including steel and paper mills.
"There are a number of industries that produce fine particulate or dust, which is a significant concern healthwise," Bayless says. "So anything that can get those small particles out of the air is much better from a human point of view."
Bayless and his colleagues are continuing their research, examining how their device could capture mercury -- a highly volatile, poisonous metal -- from industrial emissions.
Kurt Waltzer, clean air program manager for the Ohio Environmental Council, says Bayless' research looks promising, but it's difficult to say how effective it might be.
It's also one of a number of recent innovations targeted to control industrial air pollution.
"I think there are several interesting initiatives in pollution control because of the recognition that we need stronger standards for emission of pollutants from power plant smokestacks," Waltzer says.
What To Do
Power plant and industrial emissions have a direct effect on your health. The Centers for Disease Control and Prevention says the annual health cost in the United States of human exposure to air pollution ranges from $40 billion to $50 billion. And each year, an estimated 50,000 to 120,000 premature deaths are associated with exposure to air pollutants.
To learn more about air pollution and how it affects your health, visit the CDC or the U.S. Environmental Protection Agency online.
