How can a prehistoric volcanic eruption help us reduce the amount of CO₂ released into the atmosphere today? The answer is found in the basalt formations created by the lava – formations that can be used as sites for injecting carbon dioxide (CO₂) captured from industrial sources in a process called carbon capture and storage (CCS).

The Big Sky Carbon Sequestration Partnership, one of seven Department of Energy (DOE)  regional partnerships conducting carbon storage research with funding from the National Energy Technology Laboratory (NETL) and industrial partners, recently injected 1,000 metric tons of CO₂ into the Grande Ronde Basalt Formation in eastern Washington. This first-of-its kind injection is part of research meant to determine if basalt formations could provide a long-term solution for storing CO₂, a potent greenhouse gas.

The half-mile-deep basalt formation was created by layer upon layer of ancient lava flows. As the lava cooled in each layer, the upper portion solidified faster and became more cracked and porous than the slower-cooling lower portion of the layer. Lab testing done by DOE’s Pacific Northwest National Laboratory (PNNL) on samples from the region shows that chemicals in the basalt react with CO₂, converting it to solid calcium carbonate, or limestone, over just a few months. By injecting liquid-like CO₂ into the porous part of a layer, researchers hope for the same results, which would prevent gaseous CO₂ from escaping to the atmosphere. Thick, impermeable basalt above the injection layer provides further insurance that the CO₂ will remain in place while the chemical conversion occurs.

The site is thought to be ideal for CO₂ injection. Pre-injection characterization activities identified no significant faults or fractures, and the groundwater in and immediately above the injection layer was already unsuitable for human use because of its high fluoride content.

So, over the next 14 months, researchers will test fluid samples from the injection well to determine changes in the chemical composition compared to pre-injection samples and computational predictions. Sensors in the well will monitor for potential CO₂ leakage, detecting it before it reaches the surface or area aquifers. Rock samples will then be collected and tested for limestone crystals at the end of the 14-month period, and the well will be capped.

Major parts of Washington, Oregon, and Idaho lie above the ancient lava flows tested in this project. Similar underlying basalt formations are common worldwide and could be put to the same use, helping reduce industrial CO₂ emissions by permanently storing them underground.

Led by Montana State University, the Big Sky Carbon Sequestration Partnership is conducting this research project with Battelle Memorial Institute (Columbus, OH), which operates PNNL. Boise Inc., a packaging and paper products company headquartered in Boise, Idaho, owns the property in Wallula, Wash., where the injection took place. Praxair (Danbury, CT) provided the CO₂ for the test, and Royal Dutch Shell (London, UK) and Portland General Electric (Portland, OR) are assisting the $12 million project with additional funding. Schlumberger Carbon Services (Houston, TX) is providing some of the funds for modeling and geophysical services.

The Regional Carbon Sequestration Partnerships were formed in 2003 to investigate safe, permanent, and economical methods to store CO₂ emissions in their respective areas of the country. The Big Sky Partnership covers Montana, Wyoming, Idaho, South Dakota, and eastern Washington and Oregon.