Brimstone Energy, a start-up funded by Bill Gates, has announced plans to produce climate-neutral cement. Currently, the cement industry is responsible for approximately eight percent of global carbon dioxide emissions. However, existing technologies have been unable to prevent these emissions, as cement is made from limestone that contains carbon. During the manufacturing process, limestone is turned into calcium oxide, releasing carbon dioxide. Even if the energy used in the process came entirely from renewable sources, process emissions would still occur. Previous attempts to produce climate-friendly cement have only been able to reduce emissions, not eliminate them. The only option has been to capture emissions directly during production using Carbon-Capture-and-Storage-Technology (CCS), which is not widely used in the industry.
Brimstone Energy has now announced a climate-neutral manufacturing process for ordinary Portland cement. This process is based on the raw material calcium silicate, which is abundant in the earth’s crust and does not contain carbon. As a result, process emissions would be eliminated. The resulting cement would be chemically identical to that produced by conventional cement plants. The company also plans to produce other materials that can be added to the cement, using slag from steel mills and fly ash from coal-fired power plants. Additionally, the company claims that their process produces magnesium compounds that bind carbon. In the best-case scenario, Brimstone Energy’s innovative cement manufacturing process could even achieve negative emissions.
According to CNBC, two investment funds recently invested $55 million in the start-up, including Breakthrough Energy Ventures, an investment fund founded by Bill Gates that exclusively invests in climate protection technologies. The cement industry is responsible for a significant portion of global carbon dioxide emissions, and Brimstone Energy’s announcement could be a significant step towards reducing these emissions.
