These scientists have turned CO2 gas into stone
Sunday, June 12, 2016, 1:53 PM - Turning the catalyst of much of climate change -- carbon dioxide emissions -- into harmless stone sounds like a bizarre fantasy plot, but a team of scientists have figured out how to make it happen.
Beginning in 2012, Iceland's Hellisheidi geothermal power plant began mixing CO2 emissions into hot water pumped from the earth, and re-injecting it into the volcanic basalt rocks that make up a good chunk of the volcanically active country's landscape.
The process of chemical CO2 absorption into basaltic rock was thought to take hundreds or thousands of years. However, the scientists found that the process at Hellisheidi took much less time, with 95 per cent absorption over less than two years.
The resulting CO2-bearing rock looks no more remarkable than any other lump of stone, like the drill core displayed below by study co-author Sandra Snaebjornsdottir.
Image credit: Kevin Krajick/Lamont-Doherty Earth Observatory
CO2 is a potent greenhouse gas, whose levels have been rising drastically since the late 19th Century, accelerating in recent decades.
As world governments struggle to come to terms with the best way to bring down emissions -- even in Iceland, where geothermal energy much 'cleaner' than traditional sources -- the ability to capture CO2 and keep it from entering the atmosphere could be a real boon.
"This means that we can pump down large amounts of CO2 and store it in a very safe way over a very short period of time," study co-author Martin Stute said in a press release from Columbia University. "In the future, we could think of using this for power plants in places where there’s a lot of basalt—and there are many such places."
The method, which the scientists say would be ideal for fossil-fuel plants, still has some hurdles to overcome. It requires around 25 tonnes of water for every tonne of CO2, and while seawater would suffice (and an earlier Columbia study found there was no shortage of basalt offshore), it would still be a challenge for plants far from the ocean.
In Saskatchewan, a carbon capture program at the Boundary Dam power station was plagued by technical problems and cost overruns since it was first opened, although a recent article in the Leader Post says the plant is now set to capture around 800,000 tonnes of CO2, or the equivalent of taking 200,000 cars off the road.
The new study was published in the journal Science.