Geologic

Using Earth's Geology

Geologic storage of carbon dioxide is a critical component of negative emissions technologies. Underground geologic formations offer immense capacity for permanent storage of CO2. Natural interactions between the atmosphere and the Earth's surface also provide promising approaches to durable, large-scale carbon storage.

Enhancing Natural Processes

When CO2 interacts with rocks rich in calcium, iron, or magnesium, it can turn into rock through mineralization. Alternatively, CO2 can break up the surface metals and form a stable bicarbonate ion (HCO3-) in a process known as weathering. In either case, the CO2 is stored for tens of thousands of years, or even longer. Geologic processes like weathering and mineralization already draw down an estimated 1.1 billion MTCO2 a year. Under the right conditions, we can accelerate and scale these reactions to store additional gigatons of CO2.

Geologic Goals

Where We're Going

Our Geologic Program includes projects that will grow in impact into the future.

We are developing novel, engineered methods for rock-based removal and storage as a long term, permanent carbon storage strategy. We anticipate the impact of these projects will grow into the future.

Our projections show two categories: risk adjusted and total potential opportunities. Overall projections are based on our estimates of the overall carbon containment and destruction potential of the Geologic Program.

Risk-adjusted projections are derived from those overall estimates but factor in reasonable limitations given risks on deployment and adoption of the technology, and challenges based upon market factors.

Scaling Earth's Natural Processes

Sourcing Feedstock

Weathering and mineralization efforts need to consider logistics from the start. Scaling geologic processes will require a steady supply of high-purity CO2, as well as rock and mineral feedstocks. The CC Lab conducts extensive research and spatial analysis to locate accessible sources and transport routes for these materials. Our goal is to build a reliable, cost-effective, and efficient feedstock network capable of weathering or mineralizing millions – and eventually, billions – tons of CO2.

The Lab is developing transportation and logistics models for feedstock sourcing. CC Lab, 2022.

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Opportunity in basalts

Basalt geological formations, like those found along the Columbia River in Washington and Oregon, can permanently sequester carbon dioxide. This process involves the formation of solid carbonate minerals (calcite, magnesite, ankerite, dolomite, and a variety of magnesium-carbonate minerals) through the reaction of CO2 with calcium-, iron- or magnesium-rich rocks. The CO2 then turns into rock as solid carbonate minerals form in the pore spaces of the basalt.

The timescale of these reactions has been studied in Iceland, Norway, and Japan, and in the Pacific Northwest National Laboratory (PNNL) in Wallula, WA. In Wallula, post-injection testing indicated that ~60% of CO2 was mineralized within two years.

While other potential reservoirs present risks of CO2 leakage, mineralization ensures the greenhouse gas will remain locked underground permanently.

Basalt formation in the Pacific Northwest. CC Lab, 2022.

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Enhancing natural processes

When atmospheric carbon dioxide mixes with water and silicate or carbonate minerals, it can dissolve those minerals in a process called weathering. Weathering is a key step in the natural inorganic carbon cycle that helps regulates the Earth’s climate.

By crushing silicate or carbonate rocks into fine particles, we can increase their reactive surface area and rate of dissolution – speeding up and scaling the weathering process. This method of removal is called enhanced weathering (EW).

EW can be a powerful carbon removal solution, but most applications to date rely on methods that are difficult to measure. In our CREW project, the Lab is currently developing methods of EW that are more easily tracked and measured. This ensures we can accurately verify the carbon removed by the system.

An olivine mine in the Pacific Northwest. CC Lab, 2022.