The reaction of storing carbon underground can cause cracking. That is good news.

The reaction of storing carbon underground can cause cracking. That is good news.

A promising way to remove carbon dioxide from the atmosphere is to pump it into the ground, where it can react with certain rocks Convert gas into solid minerals.

Before implementing this approach on a large scale, scientists still have many questions to answer. One question is what will happen as the carbon mineralization process develops-will the newly formed minerals block the pores in the rock and prevent more carbon dioxide from entering? Or, will the additional minerals cause the surrounding rocks to rupture, opening up new areas, and allowing more carbon dioxide to enter, react, and store?

The new laboratory results presented at the fall meeting of the American Geophysical Union on Monday may have solved the case. They believe that although there will be considerable blockages over time, cracks will also form, which can keep the reaction in a self-sustaining cycle.The research has not been published yet, introduced by the lead author Catalina Sanchez-Roa, Associate research scientist at Columbia University Lamont-Dougherty Earth Observatory.

“Carbon capture and storage is by far the only technology that can reduce the concentration of atmospheric carbon dioxide that causes climate change,” Sanchez Roa said in a pre-recorded speech. “We are interested in carbon mineralization because it is one of the safest ways to store carbon,” she added, and because it uses a naturally occurring process.

Sanchez-Roa and her colleagues started with a sample of pure quartz, a rock from the mantle that can combine with carbon dioxide to form a solid carbonate mineral. The team pulverized pure nickel into powder and pressed it together to form a tubular sample. They then put the tube into a machine called a triaxial deformation device, which simulates the temperature and pressure conditions in real rock reservoirs used for carbon storage that might be found underground. The machine is also equipped with a variety of sensors that can measure how the characteristics of the rock material change when carbon dioxide is repeatedly injected into the rock material within 35 days.

The triaxial deformation device simulates underground conditions and measures the response of the sample to CO2 injection.Source: Introduction by Catalina Sanchez-Roa

They found that the density of the sample increased over time, while its permeability decreased. This means that some blockages occurred during the conversion of carbon dioxide into magnesite, quartz, silica and elemental carbon.

The machine also measured several unexpected acoustic emissions, combined with other measurements, such as a decrease in pore pressure and an increase in volume, indicating that cracks are forming in the sample. The cracks seem to help the permeability to remain low but stable, rather than continuing to decline as in the early days of the experiment.

Researchers Indicate in their abstract This is the first experimental evidence to record cracking during carbon mineralization, and cracking helps maintain permeability. They wrote: “These results confirm that the carbon mineralization process can be self-sustained through reaction-driven cracking (at least on a partial scale), and this process is critical to upgrading engineered carbon mineralization into an effective and safe CO2 method. Store.”

Next, they hope to continue to experiment in complete rocks and explore which temperature and pressure conditions are best for promoting cracking.

Sanchez-Roa’s co-authors include Ah-Hyung Alissa Park and Marc Spiegelman of Columbia University, and Jacob Tielke, Christine McCarthy, and Peter Kelemen of the Lamont-Doherty Earth Observatory in Columbia.