American green-steelmaking startup, the most recent of the three firms pursuing electrolytic or novel chemical routes to carbon-free iron. Founded by Laureen Meroueh, Hertha uses methane pyrolysis—heating pure methane until it breaks apart into hydrogen and carbon—then injects both into a molten mixture of iron ore inside an electric-arc furnace, a standard piece of equipment normally used to melt scrap steel for recycling. The hydrogen reduces the iron oxide; a proportion of the carbon adjusts the carbon content of the resulting liquid metal. Impurities are removed as slag by reaction with calcium and magnesium oxides, and the iron sinks beneath the slag for tapping.
Because the reaction vessel is an off-the-shelf electric-arc furnace, Dr Meroueh's laboratory prototype is already producing several hundred tonnes of iron a year. She plans to scale to 10,000 tonnes by the end of 2027 and to full-size modules producing 300,000–500,000 tonnes by 2030. The process could be adapted to use electrolytic hydrogen, and thus become completely green, if the price of that gas were to fall sufficiently.
After the game the king and the pawn go in the same box.