In Search of Pollution-Eating Bugs

An innovative project that could lead to cleaner air for all of us proves once again that to find the answer to the really big questions, scientists sometimes have to think small. Very small.

The goal is to remove carbon dioxide, one of the key greenhouse gases, from smokestacks at fossil-fueled power plants. Lots of people have tried, with little success, but the cooperative efforts of three institutions, with support from the nation's oldest national park, just might provide the answer.

David Bayless, a mechanical engineer at Ohio University in Athens, initiated the project a few years ago when he reasoned that nature has its own way of dealing with carbon dioxide. It provides organisms that convert the gas through photosynthesis into useful byproducts, like oxygen.

So why not, Bayless asked, find some creature that could eat that junk as it comes out of the stack?

It turns out that the best candidate isn't some exotic, genetically engineered beast that loves to dine on carbon dioxide. It's just cyanobacteria, tiny micro-organisms commonly known as green slime. Cyanobacteria does, indeed, have a passion for CO2, and what's more important it can survive in the blistering temperatures of gases streaming out of a coal-fired furnace.

The technology has already proved itself on a demonstration scale, with some limitations. What remains to be seen is whether it will work on a fully operational power plant.

Looking For a Few Good Bacteria

But scientists need to find just the right kind of cyanobacteria, tiny green microbes that give the algae its name. To find it, Keith Cooksey, professor of microbiology at Montana State University at Bozeman, has turned to Yellowstone National Park, in hopes of finding a few stalwart microbes that he can grow and propagate in his lab.

These have to be hardy fellows, able to thrive in temperatures above 130 degrees Fahrenheit, with a strong appetite for carbon dioxide.

"I'm sure the ideal bug is out there somewhere," Cooksey says. "All we have to do is find it." The concept has earned a $1 million grant from the U.S. Department of Energy, all because Bayless asked a simple question several years ago.

He was working for American Electric Power, a Midwestern power supplier that generates 90 percent of its electricity from coal. One day Bayless found himself in a room full of company executives, and he asked what they were most worried about.

"If a carbon tax ever comes, we're dead," he was told.

Coal produces a lot of carbon dioxide, and if officials imposed a "carbon tax" in an effort to force companies to clean up their stacks, it would drive many of them out of business, Bayless was told.

So he set out to find what kind of research was underway. Not much, he soon learned. The leading solution was to pump the gas deep into the ocean, and hope it doesn't come back up anytime soon.

"I'm just fundamentally opposed to that kind of solution," Bayless says. At some time, he adds, it would "come back and bite you."

"So I started thinking, nature deals with carbon dioxide by photosynthesis," the process by which plants and animals use sunlight to convert chemical compounds into energy. Why not find some kind of creature that could survive at high temperatures and absorb the CO2?

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