Travertine Makes Sulfuric Acid While Sequestering Carbon

Technology startup Travertine has developed a process to remove carbon dioxide (CO2) from the air and sequester it permanently, while also making sulfuric acid, reportedly the most used inorganic chemical in the world. Travertine’s aim is to leverage the sulfuric acid to develop applications for fertilizer production and to recover critical elements from mines to help advance the transition to renewable clean energy.

The proprietary electrochemical process involves recovering sulfate waste generated from industries and upcycling it into sulfuric acid. The calcium and magnesium in the sulfate are reacted with CO2 in the air, resulting in generation of carbonate minerals to sequester the carbon. Carbonate minerals, found in limestone, marble, and cement, among natural resources and building materials, are the earth’s reservoir for CO2, sequestering it over tens to hundreds of millions of years.

“By converting CO2 from the air into a mineral we permanently sequester it in a way that mimics the way the earth sequesters it. And in regenerating sulfuric acid from sulfate waste, we avoid accumulation of that waste, eliminating water and soil pollution, while continually recycling and reusing it,” says Laura Lammers, Travertine founder and CEO and former University of California, Berkeley professor. The company spun out from her lab work at Berkeley involving exploring carbonate mineralization as an energy- and cost- efficient way to reduce the environmental impact of critical mineral extraction.

Figuring out how to capture and store enough carbon to make an impact in the climate change battle will require tremendous scale. IPCC reports confirm that tens of gigatons of CO2 will have to be removed from the air to achieve less than 2 degrees Celsius warming (determined necessary to meet the goals of the Paris Agreement), which the world is nowhere close to accomplishing.

With scale in mind, Travertine will target the mining and fertilizer industries. They are globally the largest consumers of sulfuric acid and produce hundreds of millions of tons of sulfate waste yearly that can be used to make more sulfuric acid and, in the process, capture more carbon.

“If we can use that sulfate waste from mining and fertilizer production, we have a pathway to achieve gigaton-scale CO2 removal. For every ton of sulfuric acid produced from their waste, half a ton of CO2 can be saved and sequestered,” Lammers says.

“We believe our process can help facilitate extraction of critical elements for decarbonization. And that it can help ensure extraction industries are as environmentally responsible and sustainable as possible while providing both mining and fertilizer companies an efficient, cost-effective way to deal with their waste. They currently pay billions in waste management.”

The company recently secured $3M in seed financing, led by Grantham Environmental Trust and Clean Energy Ventures, to expand its team and build a pilot plant. Travertine is building a 1kg/day pilot in its existing Boulder, Colo. facility in 2022. And is working toward building a pilot to demonstrate about 1 ton-per-day CO2 sequestration on a partner mine site, with operations beginning in early 2024.

Travertine is one of 20 companies that Clean Energy Ventures has invested in to date, spanning carbon, mobility, renewable energy production, energy efficiency, and energy management.

The firm looks for what Dan Goldman, managing partner at Clean Energy Ventures, calls “game-changing technologies” that can achieve carbon reduction impact at the gigaton scale in the coming years.

“Our global economy is facing a reckoning and we’re seeing the need to not only reduce carbon emissions across industries, but to simultaneously pull CO2 out of the atmosphere at the scale of gigatons per year. Travertine is one of the only companies on the market today that can successfully sequester gigatons of carbon without sacrificing economic viability,” Goldman says.

He points to projected rapid growth in the fertilizer and mining industries who will need net zero-emissions solutions.

“In light of surging demand and uncertain supply in both the mining and fertilizer industries, there is ample opportunity for Travertine’s innovative, cost-competitive solution to help these sectors address efficiency and waste stream challenges. Travertine is poised to scale quickly to address the biggest challenges facing these companies today.”

Lammers and her team are partnering with fertilizer producers to upcycle phosphogypsum (PG), a by-product from fertilizer production, to make calcium carbonate products that can be sold as components of green cement, as well as to make green hydrogen. (Green hydrogen and carbonate minerals that can go in cement can also be produced in the mining applications).

The young company is focusing on the energy transition space. Work to build infrastructure is projected to drive demand for sulfuric acid used to extract elements such as lithium and nickel that go into electric vehicle batteries.  But it can also extract other critical elements like platinum group metals essential for hydrogen production.

The technology is currently being tested in collaboration with potential partners in the mining industry.

Further out, the aim is to build facilities in partnership with existing major users of sulfuric acid, as well as mine sites under development in the U.S., that will need large volumes of sulfuric acid.

Travertine is also exploring possible ways the technology can be leveraged to provide sulfuric acid for other applications in the same industries it is now targeting.

The underlying goal, Lammers says, is to push for a new paradigm for resource extraction that avoids waste and allows for recycling of chemicals used in industries to drive a closed loop system.

“Extractive industries have historically been linear in the sense that they go from working with raw material to producing waste that is disposed.

We cannot continue to have linear industries because the earth is finite in resources.

Developing new ways to extract resources that avoid waste accumulation will be critical for preserving human health and the environment.”