Zero-carbon mineral reduces carbon footprint in various products

CarbonFree announced the launch of endurocal™, a zero-carbon mineral. It is designed to replace conventional calcium carbonate in a wide range of commercial products and manufacturing processes, including plastics, paints, and paper.

Calcium carbonate is a widely used and highly marketable specialty chemical, and CarbonFree will sell endurocal as an alternative to precipitated calcium carbonate and ground calcium carbonate into a domestic market worth approximately 30 million metric tons.

“endurocal represents a breakthrough in the recycled use of carbon dioxide, providing a cost-effective path for manufacturing competitiveness using emissions that would otherwise go to waste,” said Martin Keighley, CEO of CarbonFree. “Companies will now have the ability to use cost-competitive chemicals while also decarbonizing their supply chains.”

To produce endurocal, CarbonFree’s proprietary SkyCycle™ technology captures carbon dioxide from the stack of an industrial facility, preventing its release into the atmosphere. It then converts the captured carbon dioxide into high quality calcium carbonate, which is the same mineral that naturally occurs in limestone.

Virtually all applications of calcium carbonate are non-emissive, meaning the captured carbon dioxide remains securely stored no matter how the product is used. For example, approximately 30-40 percent of the contents of architectural paint is calcium carbonate, used to control brightness and increase volume. Even long after the paint has been applied, the calcium carbonate within the paint retains its carbon dioxide.

“Our endurocal product is no different on a molecular basis than conventionally produced calcium carbonate, however, it’s produced in a way that effectively eliminates net carbon dioxide emissions,” Keighley said. “We’re excited to provide companies with the opportunity to help produce and use such an innovative molecule for use domestically.”

The launch of endurocal follows CarbonFree’s definitive agreement with U. S. Steel announced in April 2024 to deploy SkyCycle on a commercial basis at U.S. Steel’s Gary Works Blast Furnaces. This project, slated to commence operations in 2027, will result in the capture of 50,000 tons of carbon dioxide annually from U. S. Steel’s facilities, which will be used in the production of endurocal. The project also will recover calcium from slag, eliminating a portion of the slag resulting from steel production.

The initial scale of the U. S. Steel project will reduce an amount of carbon dioxide equivalent to emissions from nearly 12,000 passenger cars and displace approximately 150,000 metric tons of carbon dioxide emitted from conventionally produced calcium carbonate per year.