Brimstone Energy, a startup aiming to commercialize carbon-negative cement, received $55 million in a Series A funding round, co-led by Bill Gates’ Breakthrough Energy Ventures and DCVC.
The Oakland-based company, which was founded in 2019, invented a process to make ordinary portland cement carbon negative by sourcing lime from calcium silicate rock. This new process also produces magnesium species as a waste product, which passively absorb CO2, making the Brimstone process net carbon-negative regardless of the fuel source used in the kiln.
“Cement is a miracle material that lets us build the infrastructure that is the foundation of our society and economy. It also happens to be a significant contributor to CO2 emissions during production,” said Carmichael Roberts of Breakthrough Energy Ventures. “Not only has Brimstone figured out a way to eliminate the emissions in that process – their innovation creates an opportunity where our built environment could be a net sink for carbon. This means that the buildings and bridges that we build with carbon-negative Brimstone portland cement can be a part of the climate solution instead of the intractable liability they are today.”
Brimstone will use the recent financing to build a pilot plant, which it aims to have operational in 2023.
