Iceland Project Turns 95% of Carbon Dioxide into Calcite Rock
(p. A6) For years, scientists and others concerned about climate change have been talking about the need for carbon capture and sequestration.
. . .
Among the concerns about sequestration is that carbon dioxide in gaseous or liquid form that is pumped underground might escape back to the atmosphere. So storage sites would have to be monitored, potentially for decades or centuries.
But scientists at Lamont-Doherty Earth Observatory at Columbia University and other institutions have come up with a different way to store CO2 that might eliminate that problem. Their approach involves dissolving the gas with water and pumping the resulting mixture -- soda water, essentially -- down into certain kinds of rocks, where the CO2 reacts with the rock to form a mineral called calcite. By turning the gas into stone, scientists can lock it away permanently.
One key to the approach is to find the right kind of rocks. Volcanic rocks called basalts are excellent for this process, because they are rich in calcium, magnesium and iron, which react with CO2.
Iceland is practically all basalt, so for several years the researchers and an Icelandic utility have been testing the technology on the island. The project, called CarbFix, uses carbon dioxide that bubbles up naturally with the hot magma that powers a geothermal electrical generating plant 15 miles east of the capital, Reykjavik.
. . .
Early signs were encouraging: . . .
. . .
The scientists found that about 95 percent of the carbon dioxide was converted into calcite. And even more important, they wrote, the conversion happened relatively quickly -- in less than two years.
"It's beyond all our expectations," said Edda Aradottir, who manages the project for the utility, Reykjavik Energy.
. . .
. . . the researchers say that there is enough porous basaltic rock around, including in the ocean floors and along the margins of continents.
For the full story, see:
(Note: ellipses added.)
(Note: the online version of the story has the date JUNE 9, 2016, and has the title "Iceland Carbon Dioxide Storage Project Locks Away Gas, and Fast.")
The research mentioned above was detailed in an academic paper in Science:
Matter, Juerg M., Martin Stute, Sandra Ó Snæbjörnsdottir, Eric H. Oelkers, Sigurdur R. Gislason, Edda S. Aradottir, Bergur Sigfusson, Ingvi Gunnarsson, Holmfridur Sigurdardottir, Einar Gunnlaugsson, Gudni Axelsson, Helgi A. Alfredsson, Domenik Wolff-Boenisch, Kiflom Mesfin, Diana Fernandez de la Reguera Taya, Jennifer Hall, Knud Dideriksen, and Wallace S. Broecker. "Rapid Carbon Mineralization for Permanent Disposal of Anthropogenic Carbon Dioxide Emissions." Science 352, no. 6291 (June 10, 2016): 1312-14.