Saturday, September 11, 2021

'MAYBE' TECH
Research project proposes turning CO2 into stone under the sea

Geologists know that the Earth's systems naturally turn CO2 into solid carbonates, it's a matter of figuring out how to engineer the process at a large scale.

Author of the article: Derrick Penner
Publishing date:Sep 10, 2021 • 
Ben Tutolo is a geologist at the University of Calgary. PNG

University researchers want to test the idea that large amounts of carbon dioxide could be captured from the air offshore and injected into basalt aquifers deep beneath the ocean floor where it will solidify, essentially into stone.

A demonstration project won’t be cheap, $30 million to $60 million, but the consortium, which includes the University of Victoria, wants to figure out if this could be a game-changing technology in the race to stall climate change at 1.5ÂșC of warming.

“This is critically important,” said Kate Moran, project lead for the initiative under the name Solid Carbon, about carbon-capture technology. “By the middle part of the century or earlier, it has been demonstrated by the science community that we need to be removing CO2 from the atmosphere in order to keep the planet habitable.”

This test, planned for 2024, would involve injecting 10,000 tonnes of CO2 into a basalt aquifer within the Cascadia basin, 200 kilometres off the coast of Vancouver Island and under 2,700 metres of water. If it works as well as they hope, however, Moran said the technology could be developed into an industry that sequesters more than the equivalent of all of Canada’s emissions from transportation on an annual basis.

The Cascadia basin’s capacity, however, is much, much greater, she added.

What scientists know is that when CO2 is injected into porous basalt aquifers, the gas reacts with minerals in the rock to form solid, stable carbonates in a process known as basalt carbonation.

“You can look at these rocks, I have one here on my desk from southern Alberta, and it’s clear that basalt is naturally carbonated by the Earth’s systems,” said lead scientist Ben Tutolo, a geologist from the University of Calgary.

Their quest is to engineer ways of doing so faster.

Researchers with Solid Carbon also know that artificially injecting CO2 into basalt will work, because an Icelandic company called Carbfix has already been doing it, but above ground by injecting CO2 dissolved in water into rock.

Most of the world’s basalt is beneath the ocean, Moran said, and Canada has a ready-made lab to test the process in the Cascadia basin, where Oceans Network Canada has a deep-sea observatory that is already continuously monitored.

The test would likely involve ships and equipment already used by the oil and gas industry in extraction, Moran said, with offshore service companies already having expressed interest in supporting the experiment through in-kind contributions.

At production level, Moran said Solid Carbon is developing scenarios that would match direct-air-capture technology — similar to the system being developed by the firm Carbon Engineering in Squamish — powered by renewable energy. Such plants would be based on offshore rigs or drilling ships to capture and store CO2 in a whole new industry, where Canada could be “the know-how hub in the world,” Moran said.

Tutolo estimated that an industry that captures and sequesters about one gigatonne of CO2 annually, which is equivalent to more than all of Canada’s 750 megatonnes of emissions now, is a possibility.

The catch with carbon-capture technologies is cost, said Chris Severson Baker, Alberta director for the energy think-tank the Pembina Institute.

“The problem with these types of things is not that it isn’t technologically feasible, (it’s that) it’s so expensive to do,” Severson Baker said.

Carbon capture is sometimes viewed as a distraction that gets in the way of actually cutting greenhouse gas emissions, but Severson Baker said scientists acknowledge that emissions reductions alone won’t get countries to the goal of net-zero by 2050.

“I think a couple more summers of fires and floods and people are going to start to say, ‘OK, what can we do to actually make things better on this planet?’ ” Severson Baker said. “But a lot of things are going to have to happen before people are willing to spend that kind of money sucking carbon out of the atmosphere.”

In the meantime, Moran said research still needs to be done now so such technologies can be ready when they’re really needed.

“One can imagine, as we prove this particular concept — and it is needed to keep the planet habitable for humans,” carbon capture could be a “bridge” industry for skilled workers already in the oil and gas sector.

“It’s beautifully suited for that purpose, right?”

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