Brimstone Hires Materials Industry Veteran James “Tim” Rens as Chief Financial Officer to Lead Next Stage of Growth

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OAKLAND, Calif.--(BUSINESS WIRE)--Oct 30, 2025--

Brimstone, a U.S. industrial innovator pioneering a patented refining technology, today announced the appointment of James “Tim” Rens as the company’s Chief Financial Officer (CFO).

Rens brings over four decades of financial and operational leadership experience across the industrial, energy, and materials sectors. He has raised nearly $20 billion in traditional energy and energy transition industries and has served as CFO for multiple high-growth ventures since 1995.

“Tim is a world-class CFO with a proven track record in building industrial businesses and leading financial strategy, paired with a unique understanding of the economic power of co-production,” Cody Finke, co-founder and CEO of Brimstone, said. “As we scale Brimstone’s process for cement, alumina, and other materials, Tim’s expertise will be crucial in driving Brimstone's next phase of growth. Tim’s leadership strengthens our ability to deliver on our mission: to transform heavy industry and unlock material abundance.”

Rens joins Brimstone as CFO after leading financial strategy and helping raise nearly $750 million to support the first large-scale deployment of methane pyrolysis technology. With experience spanning phosphate mining, chemical manufacturing, ammonia production, oil refining, and methane pyrolysis, Rens brings deep expertise in co-production and downstream processing of natural resources within capital-intensive industries.

“Throughout my career, I’ve seen firsthand how co-production can redefine the economics and sustainability of industrial manufacturing, and I appreciate what it takes to fund and operate large industrial facilities,” said Tim Rens, Chief Financial Officer at Brimstone. “Brimstone’s Rock Refinery® technology has the potential to reshape trillion-dollar industries by creating more efficient and sustainable ways of producing the materials our world depends on. I’m thrilled to help bring this innovation to market at commercial scale.”

Rens served as CFO at several major industrial and energy companies, including Monolith Materials; Philadelphia Energy Solutions, the largest oil refinery on the East Coast; and CVR Energy, a leading petroleum refining company. His appointment follows a series of key leadership additions at Brimstone, including John Uhrie as Vice President of Engineering.

Rens joins Brimstone as the company moves toward commercialization of its technology. Brimstone’s patented Rock Refinery® process co-produces multiple industry-standard materials all from a single, globally abundant, carbon-free rock, unlocking the potential to transform a multi-trillion-dollar market. By design, all of Brimstone’s products meet existing industry standards and will be sold at commodity prices, allowing them to integrate seamlessly into global supply chains.

Throughout history, co-production has served as a foundational industrial strategy, increasing efficiency, reducing costs through shared CapEx and OpEx, and increasing profits for oil, gas, copper, tin, titanium, magnesium, and dozens of other mined products. With its Rock Refinery®, Brimstone is applying co-production for the first time to cement, alumina, and supplementary cementitious materials (SCM).

In August, Brimstone announced a long-term testing and commercial partnership with Amazon. After successful initial testing, Amazon signed an agreement to reserve annual volumes of Brimstone’s sustainable portland cement and SCM from its forthcoming commercial plant.

Brimstone recently completed its pilot plant work and is advancing toward its commercial demonstration plant.

About Brimstone:

Brimstone developed a breakthrough process to co-produce multiple industrial materials, including portland cement, supplementary cementitious materials, and smelter grade alumina. The company was founded in 2019 to develop next-generation industrial processes optimized for economics, efficiency, and sustainability. Brimstone has raised more than $80M to date from leading investors, including Breakthrough Energy Ventures, DCVC, Collaborative Fund, Amazon Climate Pledge, Fifth Wall, S2G Ventures, Acceler8, GVP Climate, Impact Science Ventures, Osage University Partners, SystemIQ, and Kajima Ventures. To learn more or get in touch, please visit Brimstone.com.

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KEYWORD: UNITED STATES NORTH AMERICA CALIFORNIA

INDUSTRY KEYWORD: OTHER ENERGY MACHINE TOOLS, METALWORKING & METALLURGY SUSTAINABILITY MINING/MINERALS ENERGY TECHNOLOGY NATURAL RESOURCES ENVIRONMENT OTHER MANUFACTURING ENGINEERING OTHER TECHNOLOGY MANUFACTURING

SOURCE: Brimstone

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PUB: 10/30/2025 10:15 AM/DISC: 10/30/2025 10:15 AM

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