Iceland-based company Carbfix recently built the world’s largest facility to capture carbon and store it safely in rocks underground. The process provides a natural, permanent solution for storing excess carbon. When it becomes scalable, this form of carbon capture could potentially help mitigate the climate crisis.
The company says the direct air capture technology can turn carbon dioxide back into rocks in less than two years. Currently, the process can pull 4,000 metric tons of CO2 from the atmosphere each year. While it only equates to taking 870 cars off the road, it’s still a step in the right direction.
Built-in the Geothermal Park in Hellisheidi, Iceland, Carbfix named this latest carbon capture project “Orca.” It’s the culmination of four years of collaboration between Carbfix and Climeworks, a Swiss company specializing in direct air capture (DAC) technology. The geothermal power plant provides the DAC units with renewable energy, while Carbfix offers a permanent solution for the captured carbon.
It works by removing CO2 from the air, separating carbon from oxygen, and collecting it in eight elongated boxes. Then, the trapped CO2 gets released from these rectangular collector boxes into a nearby processing facility. There, it’s diverted into a deep underground well, where it will remain eternally.
The collection tanks resemble the size of tractor-trailers and have large intake fans mounted to the sides. These fans help draw the air inside the collection tanks, where it’s combined with a chemical agent called a sorbent. Once the tanks get filled, a blast of heat from nearby hydrothermal vents helps release the CO2 into the processing facility.
Why basalt rocks?
As it moves underground, the carbon dioxide reacts with basalt rocks and minerals, which takes a few years. Once it’s underground, it can never become a heat-trapping atmospheric gas again. This process reverses the burning of fossil fuels, effectively capturing them and bringing them back to their source.
According to Carbfix’s website:
“Basaltic rocks are highly reactive and contain the metals needed for permanently immobilizing CO2 through the formation of carbonate minerals. They are often fractured and porous, providing storage space for the mineralized CO2. However, other reactive rocks such as andesites, peridotites, breccias and sedimentary formations containing calcium, magnesium and iron rich silicate minerals could also be feasible to do the job.”
Technology to capture carbon continues to advance but needs scaling
The fact that it takes less than two years to transform CO2 back into carbonate materials goes against prior theories. Scientists once believed it could take several hundred or thousands of years to complete this process. Hydrogen sulfides, another byproduct of burning fossil fuels, mineralizes in an even shorter timeframe – about four months.
Carbfix says that by scaling the ability to capture carbon, Europe could store about 4,000 billion tons of CO2 in rocks. The US could hold at least 7,500 billion tons. While carbon capture offers great promise to the world, it faces significant obstacles, such as high costs.
The Orca project cost about $10-15 million, a high price for removing carbon equivalent to less than 1,000 cars. However, the company says it represents an 80-fold improvement in carbon removal over the past four years. Climeworks added that companies could quickly scale and replicate the green technology as long as they have access to renewable energy and storage.
Other companies have already jumped on board to capture carbon on a large scale. Carbon Engineering, a company based in Canada, already received government funding of $25 million. They’re building a carbon capture technology to suck up carbon from the air and store it as compressed gas. Located in the American southwest, it will remove over 1 million tons of carbon dioxide from the atmosphere annually. This equates to the carbon removal of 40 million mature trees.
The company builds two types of plants: direct air capture and “air to fuels” plants. The first one keeps the carbon dioxide in the ground, while the second plant creates near-carbon-neutral fuel. It’s ideal for removing all carbon from the atmosphere, but the environment still benefits from efforts to lower emissions.
The future of carbon capture
Trees and vegetation also sequester carbon, but direct air capture facilities can accomplish this much faster. For example, it takes a newly planted tree about 50 years to offset and sequester carbon emissions. The tree could’ve died in a forest fire or other means by that time, making an effort useless. As climate change continues to spark massive wildfires, green technology used to capture carbon seems like the superior option.