Green Hydrogen Penetration in Steel Industry Operations: A Year-long Modeling Case Study

The steel industry contributes to almost seven percent of the global greenhouse gas (GHG) emissions and about one-third of the worldwide industrial carbon dioxide emissions. Extremely high-temperature industrial processes are challenging when it comes to decarbonization as reaching the needed temperature is dependent on a limited number of fuels. Several critical issues need attention, including the scaling-up process, the quality of iron ore and scrap, the accessibility of green electricity and hydrogen, and the establishing of markets for green steel. Coke and natural gas replacement and shifting towards green hydrogen as a reducing agent and as a temperature controller is a promising solution, as the cost of hydrogen production is expected to decrease drastically since the overall efficiency of generation is continuously improving. This work investigates a real case study in Europe for an industrial site that targets a 35% hydrogen penetration to replace natural gas in the electric arc furnace (EAF) auxiliary burners of a melt shop through a water electrolysis process supplied by a Photovoltaic (PV) plant. The model is integrated into an optimization equation to determine optimal system component sizes and operating schedules. The target is to minimize the average cost of hydrogen and reduce the carbon footprint. The results showed an economic challenge for the model as an 18.33 MW PV plant and a 12.38 MW electrolyzer were needed to drive the transition, and the resulting cost of hydrogen is 6.7 €/kgH₂, which is more than four times the average price of natural gas. Nevertheless, incentive policymakers may play a crucial role in green steel manufacturing. The system reduces the CO₂ emissions by up to 6902 tons per year.