Sparkling future for carbon capture?

One of my favorite folk songs from the Great Depression is “The Big Rock Candy Mountain,” which I remember hearing sung by Burl Ives, the bearded and burley tenor who, among other gigs, performed with Pete Seeger and the Weavers in the 1950s (boy, does that date me). One of the lines in the song refers to “soda water fountains” that would be found in the Big Rock Candy Mountain.

Now, it turns out, soda water may the answer to the troubling question of what to do with all that carbon dioxide it seems that the federal government wants us to collect from coal-fired power plants. New research led by the University of Manchester, published April 1 (and, no, this was not an April Fools’ joke) in the British journal Nature suggests the best way to store all that CO2 may be in water. Most research on carbon capture and storage has focused on pumping the gas into underground oil and gas reservoirs, a practice in use for decades to enhance the production of fossil fuels from these fields.

A press release from the U.K.’s National Environment Research Council notes that “the risks around the long-term storage of millions of cubic metres of carbon dioxide in depleted gas and oil fields has met with some concern, not least because of the possibility of some of the gas escaping and being released back into the atmosphere. Until now, researchers couldn’t be sure how the gas would be securely trapped underground.”

But the researchers from the U.K. and Canada found that carbon dioxide has been stored naturally for millions of years in underground water in gas fields. Stuart Gilfillan of the University of Edinburgh, the lead researcher, said, “We already know that oil and gas have been stored safely in oil and gas fields over millions of years. Our research shows that the carbon dioxide has been stored naturally and safely in underground water in these fields.”

Earlier research, according to the news release, used computer models to simulate injection of CO2 into the depleted fields. Some models said the carbon dioxide would combine chemically with minerals in the rock to form new kinds of carbonates. Others suggested the gas would dissolve in the water.
The research team decided to examine what’s going on empirically, rather than modeling the question. “We’ve turned the old technique of using computer models on its head and looked at natural carbon dioxide fields which have trapped carbon dioxide for a very long time.”

The research team measured ratios of CO2 and noble, inert gases such as helium and neon in nine gas fields in North America, China and Europe. They found that underground water is the major CO2 sink in these fields, and been for “millions of years.”

Chris Ballentine of the University of Manchester, the project director, said the research establishes a new way to look at carbon dioxide fields and storage. “This new approach,” he added, “will also be essential for monitoring and tracing where carbon dioxide capture from coal-fired power stations goes when we inject it underground – this is critical for future safety verification.”

And it may be a boon the hoboes who longed for the Big Rock Candy Mountain. When I was a kid living in Steamboat Springs, Colo., we had a public, natural soda water fountain. It was the spring that named the town (it chugged like a steamboat), and it was naturally carbonated (although with a slightly sulfurous taste and smell, if I remember correctly). Now, with just a little cola extract, we could have had something the world would have craved.