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Brimstone
Developing carbon-neutral Portland cement
Notable Achievements
- Developed the world's first process to make industry-standard portland cement without process emissions as certified by a third party and covered in the Washington Post.
- Raised a $55M Series A from leading climate investors, including Breakthrough Energy Ventures, DCVC, Collaborative Fund, Fifth Wall, S2G Ventures, Amazon Climate Pledge, Acceler8, Gatemore, Impact Science Ventures, Osage University Partners, and SystemIQ.
- Solution has been recognized by the International Energy Agency, the Washington Post, CNBC, CBS, and honored as one of TIME's Best Inventions of 2023.
Press Mentions
December 11, 2025
Brimstone Unveils “Fourth Great Refinery” Vision, Expands Roadmap to Aluminum, Steel, Titanium, Magnesium, etc. - Light Metal Age Magazine
Brimstone has unveiled its vision for a fourth Great Refinery, expanding its product roadmap to include essential materials such as aluminum, steel, titanium, and magnesium. The company’s growth...
Read on Light Metal Age Magazine »December 10, 2025
Brimstone Goes Public as ‘Fourth Great Refinery’: Product Roadmap to Include Cement, Aluminum, Steel, Titanium, Magnesium, and Other Critical Minerals
Brimstone has successfully gone public, marking a significant milestone in its development as a major player in the alternative resource sector. The company’s innovative roadmap aims to produce...
Read on FinancialContent »October 30, 2025
Brimstone Hires Materials Industry Veteran James “Tim” Rens as Chief Financial Officer to Lead Next Stage of Growth
Brimstone appointed industry veteran James "Tim" Rens as Chief Financial Officer to spearhead its growth. His extensive experience in the materials sector positions Brimstone for continued success,...
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August 14, 2025
The Trump Administration Just Pulled a $189M Grant From This Climate Startup—Here’s Why They Don’t Care
Brimstone, a climate startup, faced challenges when the Trump administration revoked a $189 million grant. Despite this setback, the company remains optimistic about its innovative carbon-negative...
Read on Inventrium Magazine »
August 5, 2025
Amazon and Brimstone Advance Lower-Carbon Cement Collaboration
Brimstone is collaborating with Amazon to innovate lower-carbon cement solutions, significantly reducing carbon emissions in construction. This partnership underscores Brimstone's commitment to...
Read on The Bakersfield Californian »
July 16, 2025
Oakland startup aims to make cement production greener
Brimstone is pioneering an innovative cement production process that significantly reduces carbon emissions. By utilizing alternative materials, the company aims to revolutionize the industry,...
Read on San Francisco Examiner »More Ventures in Energy & Environment
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