Cement is one of the most widely used materials on the planet. Producing it is a massive problem for climate change, making up roughly 7% of global greenhouse gas emissions.
Cody Finke, 34, cofounded a company called Brimstone that's trying to clean up the cement industry by making the familiar material in a new way.
Today the most popular type of cement is a variety called Portland cement. The material is formed by heating up a mixture containing limestone, which kicks off chemical reactions that release carbon dioxide. To avoid spewing out that greenhouse gas, Finke figured out how to make Portland cement with silicate rocks instead.
Brimstone's process still requires heating kilns to high temperatures, which can be energy-intensive and produce emissions no matter which ingredients are involved. But the company's final product will have properties identical to the cement used in industry today, and if renewable energy is used to heat the kilns, the company's products could be entirely emissions-free, Finke says.
Making Portland cement was a major focus during development, he adds, because customers might consider novel materials too risky to use in big, expensive projects. Another priority was making a material that could compete on cost, a distinction the company hopes to prove when it begins producing its material at a large plant.
Finke cofounded Brimstone in 2019 and now serves as CEO. In March 2024, the company received a $189 million grant from the US Department of Energy to scale up cement production. Brimstone plans to use the funding to build its first commercial plant -- which could eventually produce as much as 140,000 metric tons of cement and other co-products per year.
Cement production generates roughly the same amount of emissions globally as passenger vehicles, but the industry tends to get less attention and funding from investors, Finke says. Cement may not strike most people as an urgent climate challenge, but as he puts it, "Anyone who cares about climate should also care about cement."