A new demo plant will repurpose mining waste and also capture CO2

Travertine Technologies, a Colorado-based climate tech company, is building a multi-million dollar demonstration plant alongside a metals refining facility near Rochester, New York. The plant will recycle discarded gypsum to make sulfuric acid while removing carbon dioxide from the atmosphere.

For the project, Travertine is partnering with Sabin Metal Corp., a precious metals refiner and recycler. Travertine’s new demo plant will take gypsum — a mineral that can be used in anything from fertilizer to building materials — that is sitting near Sabin’s facility and turn it into sulfuric acid using the carbon dioxide it traps through direct air capture. Travertine will then sell the sulfuric acid to Sabin to use in its metallurgical processing.

When she founded the company in 2022, Travertine CEO Laura Lammers initially planned to build a low-cost, scalable, and permanent method for trapping carbon dioxide. But in talking with lithium miners, she realized waste from the industry could be used to permanently store the greenhouse gas, she told Canary Media.

That proposition is particularly interesting in that it could simultaneously serve to recycle waste from the mining industry and remove CO₂ from the atmosphere.

But Travertine’s 50 foot by 50 foot demo plant will be capable of removing only 45 tons of carbon dioxide a year on a net basis, according to Owen Cadwalader, the startup’s chief operations officer. That’s a minuscule amount compared both to what some other direct air capture facilities are able to remove and the amount that a recent Intergovernmental Panel on Climate Change report says must be removed from the atmosphere to fight global warming.

“​Because of the scale of global sulfuric acid use, our process has economical gigaton-scale carbon dioxide removal (CDR) potential while simultaneously eliminating industrial sulfate waste,” Lammers said in a statement announcing the company’s new demo plant. Lammers said her goal is for the company to have a plant capable of capturing half a million tons of carbon dioxide a year within a decade.

Travertine has $10.7 million in funding to pay for the project, including $7.5 million in venture debt financing from Builders Vision and $3.2 million in grant funding from the New York State Energy Research & Development Authority, according to a news release.

“This is an ideal scenario where the feedstock is…right next to us and the use is also right next to us,” Cadwalader told Canary Media.

Cadwalader said the company will put the sulfuric acid it produces in totes and place them on a truck to be transported to Sabin’s facility. The companies said they expect to be able to upcycle hundreds of tons of waste gypsum on an annual basis and that Travertine’s plant will be big enough to supply half of the sulfuric acid Sabin needs each year at that site. The company’s processes ultimately yield a calcium carbonate that stores the CO₂, which Lammers says is akin to how the Earth stores the greenhouse gas in rocks over millions of years.

The gypsum Travertine will utilize sits just yards away from where the company will build its plant and was left over from when the area was home to a gypsum mine before Sabin acquired the site in 1975. There’s enough of the mineral to supply Travertine’s plant for decades, Cadwalader said, even if Travertine were to double its sulfuric acid production.

Having Travertine’s demo plant on site with Sabin’s facility will ​“increase circularity and sustainability in our operations,” Sabin Metal strategic advisor Sam Sabin said in a statement. Sabin told Canary Media he doesn’t believe the companies have agreed on a price for the sulfuric acid yet.

The plant, which Travertine expects to be operational by the end of next summer, will be powered by electricity from the grid, Cadwalader said. The company also plans to purchase renewable energy credits, he said.

The main product Travertine is supplying to Sabin is sulfuric acid, but the company’s demo plant will also produce hydrogen, which Lammers says happens as a result of the electrolysis process the company utilizes. Cadwalader said Travertine is ​“quantifying it and then investigating how we could [use it] in the future if we were to scale up.”

Travertine recently raised additional funds on top of its financing for its demo plant.

The company earlier this summer closed an $8.5 million financing round to commercialize its processes, which was co-led by Holcim MAQER Ventures and included Clean Energy Ventures, Bidra Innovation Ventures, and the Grantham Foundation for the Protection of the Environment. And Frontier, the fund formed by Alphabet, McKinsey & Co., Meta, and other major corporations back in 2022, also agreed to pre-purchase at least $2.4 million worth of carbon removal from Travertine and five other companies shortly after the fund was founded.