If cement were a country, it would be the third largest emitter of carbon dioxide in the world.
But the world can’t live without cement so what’s the answer? One company thinks they know. And Bill Gates’ Breakthrough Energy Ventures and Amazon’s Climate Pledge are helping to fund the effort.
California-based Brimstone believe they have developed the world’s first carbon-negative cement.
How?
By changing the raw material used from limestone to calcium silicate rocks. Limestone contains calcium, the binding agent in cement. Unfortunately, it also contains carbon dioxide and when it’s superheated to 2,700 degree, the carbon is released. Calcium silicate rocks contain no embedded carbon dioxide. Better yet, it’s 200 times more abundant than limestone.
It sounds like a simple solution, but the change in raw material requires a manufacturing process change and that’s where Brimstone’s patented process technology comes into play. To date, it doesn’t appear that they have proven the approach at scale, but keep an eye on them. Hopefully, their process will be proven commercially viable.