The key here is the long-term sequestration of the carbon.
And the low cost.
From Stanford Report, February 19:
The new process uses heat to transform common minerals into materials that permanently sequester atmospheric carbon dioxide.
Stanford University chemists have developed a practical, low-cost way to permanently remove atmospheric carbon dioxide, the main driver of global warming and climate change.
The new process uses heat to transform common minerals into materials that spontaneously pull carbon from the atmosphere and permanently sequester it. These reactive materials can be produced in conventional kilns, like those used to make cement.
“The Earth has an inexhaustible supply of minerals that are capable of removing CO2 from the atmosphere, but they just don’t react fast enough on their own to counteract human greenhouse gas emissions,” said Matthew Kanan, a professor of chemistry in the Stanford School of Humanities and Sciences and senior author of the Feb.19 study in Nature. “Our work solves this problem in a way that we think is uniquely scalable.”
Enhanced weathering
In nature, common minerals called silicates react with water and atmospheric CO2 to form stable bicarbonate ions and solid carbonate minerals – a process known as weathering. However, this reaction can take hundreds to thousands of years to complete. Since the 1990s, scientists have been searching for ways to make rocks absorb carbon dioxide more rapidly through enhanced weathering techniques.Kanan and Stanford postdoctoral scholar Yuxuan Chen developed and demonstrated in their lab a new process for converting slow-weathering silicates into much more reactive minerals that capture and store atmospheric carbon quickly. A grant from the Sustainability Accelerator at the Stanford Doerr School of Sustainability is now supporting efforts to move the research into practical applications.
“We envisioned a new chemistry to activate the inert silicate minerals through a simple ion-exchange reaction,” said Chen, lead author of the study, who developed the technique while earning a chemistry PhD in Kanan’s lab. “We didn't expect that it would work as well as it does.”
Many experts say that preventing additional global warming will require both slashing the use of fossil fuels and permanently removing billions of tons of CO2 from the atmosphere. But technologies for carbon removal remain costly, energy-intensive, or both – and unproven at large scale. One of the technologies getting much interest and even early-stage investment lately is direct air capture, which uses panels of large fans to drive ambient air through chemical or other processes to remove CO2.
“Our process would require less than half the energy used by leading direct air capture technologies, and we think we can be very competitive from a cost point of view,” said Kanan, who is also a senior fellow at the Precourt Institute for Energy in the Stanford Doerr School of Sustainability....
....MUCH MORE
The combination of low cost and pretty-much-permanent sequestration has been a Holy Grail for quite a long time.
Here's a post from November 2007 - "Engineered weathering process could mitigate global warming"
And one from September 2024 - "Olivine weathering"
Between those two bookends we've had quite a few posts including:
"We’ve got carbon capture all wrong"
I don't know if I would use the word wrong but that quibble aside this article, especially deeper into it, presents some very interesting opportunities to complement current approaches.Just as a personal preference, sequestering CO2 as a mineralized solid seems like a possibly more fruitful path than either tying carbon up in plant material—because the plant dies, the carbon gets released, reforms into CO2, that whole carbon cycle thing—or as a gas buried deep under the earth's crust—the potential disaster scenario of a catastrophic leak.
But maybe that's just me....
