The biggest cement producers in the world have a big plan to cut emissions by 90%
The world’s largest cement producers are investing $75 million in Sublime Systems, a startup trying to decarbonize the cement production process at scale.
On Tuesday, Holcim AG and CRH PLC (CRH) announced an intent to purchase green cement from Sublime’s facilities and to work with the low-carbon startup on additional sites, according to Bloomberg.
“This investment advances our strategy to decarbonize construction by scaling up the most innovative technologies across our operations,” Nollaig Forrest, Holcim’s chief sustainability officer, said in a statement.
Cement is critical for making concrete and other infrastructure but its production releases an extreme amount of CO2 each year.
Reducing cement emissions has been a challenge, with the cement industry accounting for 8% of global CO2 emissions. According to certain reports, changing the composition of cement (instead of capturing emissions) may be key in reducing the material’s environmental impact.
Massachusetts-based Sublime uses clean energy and carbon-free raw materials for cement production and is backed by a proprietary, CO2-free electrochemical system it hopes will reinvent the manufacturing process in the cement industry. Sublime’s technology zaps crushed-up rocks in water, instead of heating them in lava-hot kilns. This kicks off a chemical reaction that forms the main ingredients in its cement.
Currently, Sublime plans to produce 30,000 metric tons of cement from 2026, through a new, commercial-scale manufacturing plant that is currently being built. Compared with traditional concrete, Sublime’s product was able to reduce CO2 by 90% in tests conducted at its 250-ton-per-year pilot plant.
This year, MIT spinout Sublime also won an $87 million grant by the U.S. Department of Energy that will help back the funding of the startup’s commercial-scale plant, which is expected to produce tens of thousands of tons of cement per year.
For swift market deployment, Holcim and CRH will assign dedicated teams to co-develop facilities for the commercialization of Sublime’s technology.
The startup still faces some roadblocks before its process is fully commercialized. According to Bloomberg, the capital costs tied to retrofitting cement plants could be significant. Additionally, demand for low-carbon cement may be lukewarm because the average cost is still higher than that of traditional cement, especially when the construction industry already operates on tight margins.
Leah Ellis, co-founder and CEO of Sublime, remains optimistic about costs coming down in the future.
“Cement is so inexpensive. The price of cement in the U.S. today is 150 bucks per ton,” she told Bloomberg. “And we just cannot compete with that right away.”