Friday, August 15, 2008

Bill Wolfe

Engineers are experimenting with chemical processes that could remove carbon dioxide from the flue stacks of coal-fired electric plants and store it underground.

But fast-growing algae -- the slimy green stuff that coats ponds and poorly tended swimming pools -- soaks up carbon dioxide naturally and can thrive on coal-plant fumes, said Robert Healy, an associate consultant with Burns & McDonnell, a Kansas City, Mo., engineering construction consulting firm.

The resulting algae crop could become a valuable byproduct, Healy said.

Algae processing can squeeze out oils for use as biodiesel fuel, with the leftover material converted to animal feed or other products, he said.

Storing carbon dioxide underground is costly and returns no revenue, he said. But turning the waste into something that can be sold looks promising.

Healy was one of dozens of speakers at the annual coal-industry meeting, which is being held here for the first time. The event, which ends today, drew about 4,000.

It`s too early to say whether "algae farms" would be a practical step for many power plants, Healy said, and the process would remove only a portion of the total carbon emissions.

Operations could vary in size, but "our opinion is that about 100 acres is a good target" for an algae farm, he said.

Healy said, however, that he didn`t want to present algae as a magic bullet.

"Algae is a promising option, but not the entire solution" to the world`s carbon-dioxide problems, he said.

The idea has been tested at several locations. NRG Energy, a power company based in Princeton, N.J., participated with GreenFuel Technologies Corp. to try out GreenFuel`s proprietary system at a 1,489-net-megawatt, coal-fueled power plant in New Roads, La.

NRG spokesman David Knox said that he could not discuss the results, but that the utility is "interested in seeing what evolves from the GreenFuel technology as they do further research."

"We feel that you need to invest in a lot of different technologies and advance them all," Knox said. Some "might not pan out, but you can`t tell that until you actually try to develop them."

Chip Keeling, a spokesman for Louisville`s E.On U.S., said there are no plans to work with algae at E.On`s two utilities, Louisville Gas and Electric Co. and Kentucky Utilities Co.

He added, however, that "we believe that any research and development being considered to reduce carbon and reduce global warming is worth advancing."

The U.S. Department of Energy explored the idea of growing algae to produce biofuel from 1978 to 1996 in what was known as the Aquatic Species Program.

It never proved cost-competitive with petroleum, but given the current run-up in crude-oil prices, the situation could be different now, Healy said.

A 100-acre algae-growing operation could produce about 4 million gallons of fuel a year -- more oil than would be generated with traditional biodiesel crops such as soybeans, he said.

Because of the space requirement, algae facilities would be practical only at plants in rural areas with room to spread out, Healy said.

The possible use of algae hasn`t received much mainstream media attention, but it has been discussed in environmental magazines and on blogs, he said.

"I think there`s a lot of promise," Healy said. "There`s also a lot of skepticism, justifiably so.

"I think what we need to do is invest the time and money to actually move this forward."

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