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Travertine, a 4 Corners grantee, is turning industrial waste into carbon-negative building materials while recycling sulfuric acid and removing CO₂ from the atmosphere. Their breakthrough process could decarbonize the cement industry and scale to gigaton-level carbon removal. Founded in 2022, Travertine has operations in Boulder, Colorado and Rochester, New York. The company is developing a method to recycle industrial waste while permanently removing CO₂ from the atmosphere and capturing it in mineral form. Since its founding, Travertine has made significant strides in carbon removal through this novel process.
Founded by Laura Lammers and Owen Cadwalader, Travertine’s approach tackles the climate crisis on multiple fronts. They recycle sulfate byproducts—mainly from mining and fertilizer industries—into valuable outputs:
- Sulfuric acid, used in precious metals refining
- Green hydrogen, a clean energy carrier
- Precipitated calcium carbonate (PCC), a carbon-storing substitute for limestone in cement
These outputs enable the decarbonization of mining, energy, and building sectors simultaneously.
The 4 Corners grant supported Travertine’s Boulder Block project, a laboratory-scale pilot in Boulder, Colorado. The team captured atmospheric CO₂ and used it to create PCC. This material was then sent to a cement lab, where it was successfully tested in blocks that met standard performance and strength criteria.
As large purchasers of cement-based materials, local governments are key players in advancing low-carbon building technologies. Travertine’s innovation gives them a powerful new tool to meet emissions reduction targets.
Cement production is notoriously carbon-intensive. About half the emissions come from decomposing limestone; the other half comes from the extreme heat (up to 1,400°C) needed in the kiln process. Travertine’s PCC can replace mined limestone, reducing both sources of emissions—making concrete not just lower-carbon, but potentially carbon-negative.
Travertine’s facility is located near a metals refinery, allowing it to source discarded gypsum, a byproduct from mining and fertilizer operations. This gypsum is transformed into sulfuric acid and sold back to companies like Sabin Metals, creating a true circular economy.
The demand for sulfuric acid worldwide makes Travertine’s model not just sustainable but scalable. Its potential to reach gigaton-scale CO₂ removal is anchored in this global demand, making it a major player in the future of industrial decarbonization.
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