Greenhouse Gas was pumped into basalt rock and turned into limestone in just two years

By: Henrik Bendix

Scientists started pumping CO2 into the basaltic rock in Iceland in 2011. After just two years, 95 per cent of the greenhouse gas had been converted in solid calcium carbonate, also known as limestone.

Scientists have developed a fast and secure type of carbon capture and storage (CCS) and successfully demonstrated that the greenhouse gas CO2 can be converted into solid limestone in just two years.

CO2 is dissolved in water and pumped into volcanic basalt rocks. Here it is transformed into calcium carbonate--limestone--where it can be safely stored as solid rock and help to combat climate change.

“Within two years, 95 per cent of the CO2 we injected had been converted into calcium carbonate--a very stable material,” says co-author Knud Dideriksen, assistant professor at the Nano-Science Center and Department of Chemistry at the University of Copenhagen, Denmark.

The study is published in the journal Science.

New method: fast and safe

 One of the problems with existing CCS techniques is that CO2 gas can easily escape from the ground, says Dideriksen."It means that you have to monitor the places where you inject CO2 to make sure it doesn’t escape," he says.

But this problem is tackled by dissolving CO2 in water."We dissolved the CO2 [in water], making it heavier than the liquid already down there. The solution dissolves the [basalt] rock and reacts with the CO2 and rapidly forms calcium carbonate," says Dideriksen. "Our method is a fast, effective, and safe way to inject CO2."

Well-known methods takes thousands of yearsThe speed with which the new method converts CO2 into a solid rock is promising, says senior scientist Niels Poulsen from the Geological Survey of Denmark and Greenland (GEUS), who has studied CCS techniques for many years. He was not involved with the new research.

“[The chemical reaction] can take somewhere between 1,000 to 10,000 years in a sandstone reservoir. In the basalt, the CO2 is converted so quickly that it doesn’t have the opportunity to escape through cracks in the rock. It’s incredible that it can happen so quickly,” says Poulsen.

Dideriksen agrees.The pilot project CarbFix lies 25 kilometres from Iceland’s capital city, Reykjavik. Here, thousands of tons of dissolved CO2 have been pumped underground and transformed into limestone. (Photo: Juerg Matter)

“The CO2 was converted much faster than we ever hoped. Calculations showed that it could take eight to ten years, but it went much faster. Of course, we’re very happy,” he says.

CCS under way in Iceland

At a test site east of Reykjavik, scientists have pumped up to 230 tons of dissolved CO2 into the calcium-rich basaltic bedrock.

The water easily penetrated the porous, fine-grained rocks, down to a depth of 400 to 800 metres. They added a tracer to the dissolved CO2so they could see if any of it escaped later on.

Eventually the pump broke down as it had become completely in-filled with calcium carbonate. The scientists took a bore sample of the newly formed calcium carbonate to confirm that it was formed by the pumped CO2 and they were astounded by how fast the whole process had been.

Reykjavik Energy are already adopting the technique and plan to inject 10,000 tons of CO2 per year, says Dideriksen.

Ideal CCS for Industry

CCS has the potential to reduce global warming by removing CO2 from the atmosphere and storing CO2 emissions from industry.

“In Denmark we’re moving quickly towards carbon-free energy mix. So I don’t think that CCS is necessary for our energy production, and the same goes for other developed countries,” says Poulsen.

“But many developing countries are still dependant on coal, and we have a lot of high emission industries that we cannot do without such as the steel, cement, aluminium, fertiliser, and paper industries. It could be interesting if we could store a part of this CO2,” he says.

“The U.S. is working on a method to capture CO2 straight from the atmosphere. That would allow us to deal with emissions from traffic. And if you have a power plant running on a biofuel such as wood chips or pellets, then we can reduce the atmospheric content of CO2 by injecting and storing the CO2. There’s a future for this,” says Poulsen.

The Murray-Darling Plan

May 2018

The Murray-Darling Plan appears to be on track to deliver the full environmental flow that SA needs for a healthy river and lake system. But not everyone is convinced. Tory Shepherd reports. 

AFTER weeks of argy-bargy over the Murray-Darling Basin Plan – and warnings that the whole $13 billion plan could fail – suddenly everything’s back on track, the Federal Government says. What happened? 
Here are the numbers you need to know. 
A gigalitre (GL) is one thousand million litres. 
Scientists have said we need to keep thousands more gigalitres in the river system each year to keep it healthy. There is disagreement about exactly how many. 
The Plan promises to deliver an extra 2750GL a year from next year, and is already delivering more than 2000GL a year. Then from 2024 there’ll be another 450GL, taking the total per year to 3200GL to flush out salt, and hopefully keep the Murray Mouth, the Coorong and the Lower Lakes in good health. 
Of the 2750GL, the Government was fiddling with two buckets of water – one worth 70GL and one worth 605GL. Based on advice from the Murray-Darling Basin Authority, the Government made adjustments to the Plan so that farmers in the Northern Basin won’t have to return 70GL to the river, while in the Southern Basin they’ll have to find other ways to deliver the equivalent of the 605GL. 
The Greens tried to overthrow those changes, saying if it wasn’t “real” water, it would never materialise. The Centre Alliance also had serious concerns about how to measure and monitor how the environmental outcomes would be achieved with proposed “alternative measures” . 
But last week Labor jumped on board with the Government , so those changes stand. Labor’s conditions included increased compliance and transparency and – critically for South Australia – a guarantee the whole 3200GL would be delivered. 
That means the Plan will continue – but it doesn’t mean everyone’s happy. So what do people think?

 
LOCALS

Coorong District Council Mayor Neville Jaensch said the outcome was a “compromise” , but that “some Plan is better than no Plan” . 
“We want the full quid ... we want the Plan delivered on time and in full,” he said. 
“The big fear for us is if the whole thing was to fall over, particularly at our end of the Basin, we’d be among the people paying the heaviest cost. 
“I have concerns that there will potentially be less water, but the fact the Plan is still alive and operational is still important .” 

CONSERVATIONISTS

A range of conservationists and academics raised concerns about the Plan going ahead with the amendments – mostly because of a lack of trust after reports of rorts and water theft, and because of doubts over whether the environmental outcomes would ever be delivered . 
The Australian Conservation Foundation said the cuts were “premature and reckless” . 
“( They put) at risk the health of flood plains, wetlands and wildlife that call the Basin home,” ACF director of campaigns Dr Paul Sinclair said. 

FARMERS

You can’t really lump all farmers in together. While the farming groups were pretty happy about the deal, some individuals are still concerned. 
Cotton Australia rejoiced in the news. 
“With the full implementation of the Plan back on track, it is important that everyone now focuses on optimising environmental outcomes , while minimising the social and economic impacts of the Plan,” general manager Michael Murray said. 

GREENS

South Australian Greens Senator Sarah Hanson-Young was the one who moved the disallowance motion to overturn the changes, so she was never going to be happy. She accused Labor of teaming up with the Government to sell the Murray down the river. 
“This is worse than a shocking deal from the Labor Party and the Turnbull Government. It’s a heartbreaking one,” she said. “They have teamed up to put the entire health of the Murray Darling Basin at risk. The Coorong and SA’s Lower Lakes are dying. Our river system needs more water, not less.” 

CENTRE ALLIANCE

Senator Rex Patrick – a man with a forensic eye for detail – was not satisfied with the Government’s promises that the Plan’s outcomes would be delivered . He said there was a lack of detail in the 36 projects that were “alternative measures” to the 605GL. 
“Centre Alliance is not willing to vote for such a crucial amendment to the Plan while a lack of transparency remains,” he said. 

INDIGENOUS

The Murray Lower Darling Rivers Indigenous Nations were part of the deal with Labor. Through “cultural flows” , they’ll get $40 million for “cultural and economic water entitlements” . But they’re not happy with the 605GL change, saying it will undermine some of the Plan’s outcomes. 
“This agreement represents a further step away from a meaningful water recovery target, which the science shows is essential to restore our greatest river system to health,” acting chair Grant Rigney said. 

FEDERAL GOVERNMENT

Federal Water Minister David Littleproud’s approach is in stark contrast to his predecessor’s . Former minister Barnaby Joyce seemed to be on the side of the upstream irrigators, happy for as much water as possible to come out of the system . But Mr Littleproud has taken a more consultative approach – proven by his ability to get Labor on board. 
He said he hoped the result would bring people relief “after six years of these water wars” . 
“I thank Labor’s Tony Burke for negotiating with me in good faith. Lasting results in politics are rarely achieved by going to war,” he said. 

FEDERAL OPPOSITION

Opposition water spokesman Tony Burke said there would still be risks to the Plan in the future – but Labor changed its stance to ensure that at least there was a Plan in place. He said the projects at the heart of the disallowance vote needed to be “constantly monitored” . 
“While we will all remain vigilant, I am confident that the agreements will be honoured,” he said. As a final safety net, he said if the projects don’t work to save the river, the water would be bought back. 

THE AUTHORITY

The Murray-Darling Basin Authority – whose job is to implement the Plan – says it is now closer to “in-full , on-time implementation of the Basin Plan” . Chief executive Phillip Glyde said the Plan was working , “generating positive environmental outcomes and driving improvements in irrigation efficiency and productivity” . 

WHAT NEXT? 

Everything may be going swimmingly in the world of water – for now. But the state’s royal commissioner Bret Walker said all or parts of the Plan could be unlawful. That leaves open the possibility of a legal challenge.