Study sheds light on what happens underground when CO2 is injected into basalt

New research gives precise look at underground CO2 abatement process.

Environmental scientists testing carbon dioxide abatement are using underground basalt flows to contain and convert the gas to an inert mineral. A new series of experiments conducted at Washington University give a new, precise look at the process. (Photo: Joe Angeles/Washington University)
Environmental scientists testing carbon dioxide abatement are using underground basalt flows to contain and convert the gas to an inert mineral. A new series of experiments conducted at Washington University give a new, precise look at the process. (Photo: Joe Angeles/Washington University)

At the point when petroleum products are singed, carbon dioxide (CO2) is radiated. As the gas rises and ends up caught in the climate, it holds warm as a major aspect of a procedure called the nursery impact.

The expanded temperatures related with the nursery impact can cause softening ice tops, higher ocean levels and lost regular environment for plant and creature species.

Ecological researchers attempting to moderate the impacts of CO2 have tried different things with infusing it profound underground, where it ends up caught. These trials have fundamentally occurred in sandstone aquifers, in any case, the infused CO2 essentially stays present as an air pocket that can come back to the surface if is there are break in the topping development.

Giammar assembles a stainless steel pressure reactor in his lab. The reactor was designed to simulate conditions deep underground, and test how much CO2 basalt can trap and convert within its pores. (Photo: Joe Angeles/Washington University)
Giammar assembles a stainless steel pressure reactor in his lab. The reactor was designed to simulate conditions deep underground, and test how much CO2 basalt can trap and convert within its pores. (Photo: Joe Angeles/Washington University)

An alternate approach utilizing basalt streams as infusion destinations — mostly at the CarbFix site in Iceland and in Washington state — has yielded sensational outcomes. Metals in basalt can change CO2 into a strong dormant mineral in a matter of months. While the new technique holds guarantee, the underground infusions can be loose, hard to track and measure.

A new study by the Washington University in St. Louis enlightens what actually happens when CO2 is injected into basalt. According to scientists, it could help them illustrate how effective the volcanic rock could be as an abatement agent for CO2 emissions.

Daniel Giammar, the Walter E. Browne Professor of Environmental Engineering in the School of Engineering & Applied Science said, “In a field site, you inject the carbon dioxide in, and it’s a very open system. You can’t get a good constraint in terms of a capacity estimate. You know you made some carbonate from the CO2, but you don’t really know how much. In the lab, we have well-defined boundaries.”

Scientists collected samples of the rock from Washington state, where researchers previously injected a thousand tons of CO2 gas deep underground into a basalt flow. They then placed the rocks in small reactors that resemble slow cookers to simulate underground conditions, and then injected CO2 to test the variables involved in the carbonization process.

Scientists kept the basalt in the pressurizers and followed up, utilizing 3-D imaging to dissect their pore spaces at a month and a half, 20 weeks and 40 weeks. They could watch minute to minute as the CO2 encouraged into mineral, the correct voids inside the basalt it filled, and the exact spots in the stone where the carbonization procedure started.

Basalt rocks like these can trap CO2 gas and convert it into an inert mineral. New research from scientists at Washington University shows how much CO2 a given basalt flow can trap and convert. (Photo: Joe Angeles/Washington University)
Basalt rocks like these can trap CO2 gas and convert it into an inert mineral. New research from scientists at Washington University shows how much CO2 a given basalt flow can trap and convert. (Photo: Joe Angeles/Washington University)

Giammar said, “We reacted it at similar pressure and temperature conditions to what they had in the field, except we do all of ours in a small sealed vessel.  So we know how much carbon dioxide went in and we know exactly where all of it went. We can look at the entire rock afterwards and see how much carbonate was formed in that rock.“

Once all of the data were collected and analyzed, Giammar and his team predicted 47 kilograms of CO2 can be converted into mineral inside one cubic meter of basalt. This estimate can now be used as a baseline to scale up, quantifying how much CO2 can effectively be converted in entire areas of basalt flow.

“People have done surveys of available basalt flows,” Giammar said. “This data will help us determine which ones could actually be receptive to having CO2 injected into them, and then also help us to determine capacity. It’s big. It’s years and years worth of U.S. CO2 emissions.”

The research, led by Daniel Giammar, the Walter E. Browne Professor of Environmental Engineering in the School of Engineering & Applied Science, was conducted in collaboration with researchers at Pacific Northwest National Laboratory and Philip Skemer, associate professor of earth and planetary sciences in Arts & Sciences at Washington University.

The study is published online in journal Environmental Science & Technology Letters.

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