A team of researchers, led by Sandia chemical engineer Tuan Ho, has been using powerful computer models combined with laboratory experiments to study how a kind of clay can soak up carbon dioxide and store it.
The scientists shared their initial findings in a paper published earlier this week in The Journal of Physical Chemistry Letters.
“These fundamental findings have potential for direct-air capture; that is what we’re working toward,” said Ho, lead author on the paper. “Clay is really inexpensive and abundant in nature. That should allow us to reduce the cost of direct-air carbon capture significantly, if this high-risk, high-reward project ultimately leads to a technology.”
Carbon capture and sequestration is widely considered one of the least controversial technologies being considered for climate intervention.
“We would like low-cost energy, without ruining the environment,” said Susan Rempe, a Sandia bioengineer and senior scientist on the project. “We can live in a way that doesn’t produce as much carbon dioxide, but we can’t control what our neighbors do. Direct-air carbon capture is important for reducing the amount of carbon dioxide in the air and mitigating the carbon dioxide our neighbors release.”
Ho imagines that clay-based devices could be used like sponges to soak up carbon dioxide, and then the carbon dioxide could be “squeezed” out of the sponge and pumped deep underground. Or the clay could be used more like a filter to capture carbon dioxide from the air for storage.
In addition to being cheap and widely available, clay is also stable and has a high surface area — it is comprised of many microscopic particles that in turn have cracks and crevasses about a hundred thousand times smaller than the diameter of a human hair. These tiny cavities are called nanopores, and chemical properties can change within these nanoscale pores, Rempe said.
