The process of refining iron ore in steel production has remained largely unchanged for a long time. Most producers process the ore in blast furnaces at high temperatures using coal. This method accounts for approximately 7% of the carbon emissions that cause climate change; high costs and the long lifespans of the furnaces make the transition difficult.
Laureen Meroueh, founder of Hertha Metals, has developed a new furnace that converts ore into liquid steel in a single step and uses natural gas instead of coal. According to Meroueh, the method cuts emissions by at least half and reduces costs by 25% compared with conventional production. Iryna Zenyuk, director of the National Fuel Cell Research Center at the University of California, Irvine, says that scaling down the system and improving energy efficiency could deliver significant gains.
After completing her Ph.D. in mechanical engineering at MIT, 34-year-old Meroueh led a green hydrogen venture and founded Hertha in 2022. The company’s pilot facility in Conroe, Texas, can produce one metric ton of steel per day. Rajesh Swaminathan, a partner at investor Khosla Ventures, finds this scale impressive. Hertha had raised approximately $20 million in investment as of July 2026; Swaminathan says competitors produce less steel with $50 million or $100 million in investment.
Rather than waiting for zero-carbon production using hydrogen, the company is currently relying on fossil fuels, particularly natural gas, to keep costs low.
Why it matters
The claim that it can reduce emissions and costs simultaneously targets two fundamental obstacles in the transformation of steel production. However, the method’s reliance on natural gas sets it apart from zero-carbon production and highlights the difference between low emissions and full carbon neutrality. For now, the main uncertainty is whether the result achieved at pilot scale can also be maintained at larger production levels; expert assessment also points particularly to scalability and energy efficiency. This question concerns not only the technology’s technical performance but also whether its cost advantage will persist under different plant conditions. Therefore, while the development offers an interim option that can be implemented while waiting for hydrogen, it does not eliminate the problem of reliance on fossil fuels.