One of the fifteen XPRIZE Carbon Removal Competition winners is the innovative carbon technology company 8 Rivers Capital. The company founded in 2008, has come up with a tech called Calcite Carbon Removal offering a promising approach to direct air capture and permanent storage.
The company received an initial $1 million dollar award from the competition. It can also be awarded XPRIZE’s $80 million prize for milestone carbon removal in 2025.
8 Rivers invented the Calcite carbon removal technology in 2019 and has been advancing on it in collaboration with the Massachusetts Institute of Technology. It was also supported by funding from the US Department of Energy’s Advanced Research Projects Agency – Energy (ARPA-E) FLECCS program.
“We can think of no better way to launch Calcite than with the support of the Carbon Removal XPRIZE… We’re excited to use the XPRIZE as an accelerant to build our first Calcite plant and hope to announce its location later this year. This first facility would capture thousands of tons of carbon and progress the technology towards removing a billion tons of carbon from the earth’s atmosphere,” said Adam Goff, SVP of Strategy at 8 Rivers Capital.
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According to 8 Rivers Capital, the technology is scalable due to its simplicity and speed and it uses industrial equipment and materials that are readily available and at low cost. That makes the CO2 capture process exceptionally financially viable – less than $100 per ton of CO2 removed and sequestered.



The process starts with passing air with approximately ≈415 PPM CO2 across calcium hydroxide. The CO2 is absorbed into calcium carbonate crystals – a result of a chemical reaction similar to how concrete sidewalks reabsorb some CO2 from the atmosphere.
The warehouse fans then return CO2-depleted air with <315 PPM CO2. The calcium carbonate crystals are cycled into a kiln to regenerate calcium hydroxide and CO2. The carbon dioxide is then captured and injected underground for permanent storage. The calcium is recycled to absorb more CO2 from the air.
The company claims the Calcite process enables rapid carbon uptake at a large scale and low cost, through the use of simple and available equipment, abundant feedstocks, and optimized chemistry reactions.



“Calcite uses simple chemistry in an innovative design using a common commodity that is available at tremendous scale, meaning that Calcite is positioned to be a vital contributor to the carbon removal toolkit,” said Cam Hosie, CEO of 8 Rivers Capital.
Earlier in March 2022, the company secured another investment and established a joint venture with SK Group. The investment amounts to $100 million and represents one of the largest single private fundings in a carbon capture solutions provider to date.
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SK Group and 8 Rivers joined forces to expand 8 River’s carbon removal innovations at the pace and scale required by customers and governments. The Joint Venture will aim to combine 8 Rivers’ technology with SK’s regional footprint to deploy clean hydrogen and zero-emissions power projects across major energy centers in the Asia-Pacific region and internationally.
Recent success could position 8 Rivers at the forefront of the decarbonization market and accelerate its technologies globally. Scalable direct air capture and storage is essential for the world to remove the historic carbon emissions in the air if it has a chance to keep the 1.5C target alive.