So why — given the world has abundant basalt and an apocalyptic atmospheric CO2 problem — isn’t the CarbFix model happening elsewhere? “Good question”, says Matter. “The CarbFix model is unique because it dissolves CO2 into water (waste water from the geothermal power plant) during injection into the storage reservoir. This is an ideal situation and it is not possible everywhere to co-inject water with CO2 because of (lack of) water availability.” However, “it may be possible to inject pure CO2 into a deep basalt formation without co-injection of water”, informs Matter. Preliminary results published from a pilot CO2 injection project into the Columbia River Basalt in Washington State, have done just that. Another reason for the dominance of mainstream carbon storage in underground reservoirs is that, “the oil and gas industry is dominating the field”, Matter tells me. “They have no knowledge and expertise with ‘unconventional’ reservoirs such as basalt.”
All the carbon in the atmosphere, living creatures, and dissolved in the oceans is derived from rocks and will eventually end up in rocks, the largest carbon reservoir on Earth. The carbon moves from one reservoir to another in what is called the carbon cycle (1). Humans have accelerated this cycle by mining and burning fossil fuel since the beginning of the industrial revolution, causing rising atmospheric carbon dioxide (CO2) concentrations that are the main cause of global warming. One option for mitigating high levels of global warming is to capture CO2 and safely store it for thousands of years or longer in subsurface rocks. By accelerating carbonate mineral formation in these rocks, it is possible to rebalance the global carbon cycle, providing a long-term carbon storage solution. However, this approach is both technically challenging and economically expensive.