Coal-fired power plants, historically linked to environmental issues such as climate change and acid rain, may offer an unexpected benefit through the utilization of fly ash in concrete production. This byproduct, traditionally seen as a pollutant, can replace a significant portion of cement in concrete, thus reducing the material’s carbon footprint significantly. PHNX Materials, a startup focused on this innovative approach, has developed a method to cleanse fly ash of undesirable impurities, such as sulfur and aluminum, making it suitable for concrete companies.
PHNX Materials recently secured $2.5 million in seed funding, supported by investors including Divergent Capital, KdT Ventures, Overture, and Jane Woodward. The process not only prepares the fly ash for use in concrete but also generates additional resources by extracting sulfur and aluminum for other industries, such as the fertilizer sector. This approach leverages the historical use of ash in concrete, a practice dating back to ancient Roman times and still utilized by modern infrastructure projects like those undertaken by Caltrans, which mandates a minimum of 25% fly ash in certain projects.
The dwindling number of coal-fired power plants has led to a decrease in fly ash availability, dropping coal’s contribution to U.S. electricity from 51% to 15%. This decline has spawned a new industry focused on harvesting and refining quality fly ash from existing ash pits. Despite these efforts, a shortage persists, prompting price hikes and forcing concrete companies to reduce fly ash usage to around 8%. This reduction necessitates the use of more cement, which not only raises costs but also increases the environmental impact due to cement’s high CO2 emissions.
PHNX Materials aims to transform this scenario by unlocking new sources of fly ash, believing it to be a scalable and rapid method for decarbonizing the construction sector. Their process involves extracting valuable elements from fly ash landfills across the U.S., ultimately providing a more sustainable option for concrete production. As the company continues to explore the extraction of rare earth elements, its efforts highlight a potential shift towards more eco-friendly building materials, mitigating some of the historical environmental impacts associated with coal power.