April 10, 2011 in Nation/World

Microbes turn coal into gas

Naturally occurring process may give coal beds new life
Mead Gruver Associated Press
 
Wyoming key

About 40 percent of the U.S. coal supply comes from Wyoming, providing more than $2 billion in economic benefit to the state each year. Amid concern about climate change, the federal government estimates 15 percent of total U.S. carbon dioxide emissions come from burning Powder River Basin coal. Burning methane, however, yields half as much carbon dioxide as burning coal.

GILLETTE, Wyo. – New scientific research has a pair of energy companies betting that the future of the U.S. natural gas industry lies in persuading microorganisms to treat old coal deposits like all-you-can eat buffets.

Coal, researchers have found, is full of microbes that consume the fossil fuel and break it down into methane gas. Two companies want to take advantage of this naturally occurring phenomenon on a large scale to create vast amounts of natural gas in energy-rich places like Wyoming.

“Once you figure out the recipe that feeds the bugs and gets them reactivated, it’s pretty simple,” said Bob Cavnar, chief executive of Luca Technologies.

Luca and Ciris Energy have begun experimenting with using this type of microbe-friendly formula in gas wells drilled into coal deposits years ago. The companies have been spiking the wells with substances including calcium, magnesium, phosphate and glycerol, which encourage the microorganisms to reproduce, feed and release the coveted methane gas.

The hope is to get old and nearly tapped-out coal-bed methane wells to double or perhaps triple gas production.

The process works on a smaller scale, said Michael Urynowicz, a researcher at the University of Wyoming who has studied using microbes to turn coal into methane.

“The question is, at the field scale, how economically viable it will be,” he said.

Some worry it will contaminate the groundwater that supplies more than 6,000 area homes. What Luca calls “nutrients,” Jill Morrison of the Powder River Basin Resource Council calls “chemicals.”

“They make it sound like it’s yogurt and granola or something. It’s not,” Morrison said. “I’m not saying that maybe this technology doesn’t have some promise at some point. But I don’t think we’re there, and we don’t know enough about it.”

The experiment comes in the midst of a natural gas boom that has seen companies in several states just begin to tap vast deposits only now being recognized for their enormous potential.

But drilling for gas can require multimillion-dollar investments to bore thousands of feet into the ground. Such wells produce a lot of gas quickly, Cavnar said, but production falls off before long, requiring companies to drill more and more sites to remain profitable.

Luca officials cast aside environmental concerns, saying its process for tapping into natural gas is more eco-friendly and efficient than drilling. Acquiring methane from existing coal beds requires very little new infrastructure, Luca says, and puts to use byproduct groundwater by pumping the water back down into the coal-bed methane wells.

About 30,000 coal-bed methane wells have been drilled in the Powder River Basin in northeastern Wyoming over the past 15 years. About half are nearly or completely tapped out. “We think the source here is huge for us to be able to go in and reactivate those wells and start producing gas again,” Cavnar said.

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