U of A researcher pitches mineral carbonation as solution to climate change to U.S. p…

Wilson, a biogeochemist and an associate professor in the Faculty of Science, is studying how mineral carbonation can suck carbon dioxide, a heat-trapping gas, from the atmosphere. 

Wilson and her colleagues with the American non-profit Energy Futures Initiative recommended the United States scale up research and development of mineral carbonation by setting up a large network of test sites.

“In the U.S. there’s been a lot of movement in the last year or so toward implementing mechanisms for carbon dioxide removal from the atmosphere,” she told CBC’s Edmonton AM on Tuesday. “There’s been a lot of investment so far.”

Mineral carbonation is a natural process where carbon dioxide reacts with minerals to form harmless carbonates.

As carbon dioxide dissolves in rain water, the water becomes acidic and dissolves rock on the earth’s surface releasing magnesium and calcium into lakes, rivers and oceans.

Those minerals react with the carbon dioxide in the atmosphere and create carbonates. Calcium carbonate is the chief constituent of limestone, while calcium-magnesium carbonate is dolomite and potassium carbonate is potash.

While scientists have understood the process for a long time, they are now looking at using it to pull out large quantities of carbon from the atmosphere, Wilson said. 

“It’s something we know works and serves as a permanent store of carbon dioxide,” she said. 

There are two methods of pulling carbon from the atmosphere, one is above ground where pulverized rock, mining waste, captures atmospheric carbon dioxide. The second involves injecting carbon gathered from the air or industrial waste beneath the earth’s surface. 

Underground injection is mentioned in Episode 1 of Netflix docuseries Down to Earth which Zac Efron filmed at the Hellisheidi Geothermal Plant in Iceland. The episode shows how excess carbon is diluted in water and then piped deep into the ground where it fuses with the volcanic rock and solidifies.

Wilson says there is potential to scale up mineral carbonation to a billion tonnes a year by the end of the century, but it would require all of the waste streams of carbon dioxide and mineral wastes that Canada produces.

“There are benefits to doing it, for instance improved soil fertilization, and we can use some of the products we make, but we need to make sure we make balanced decisions about land use,” she said.