Session: 4.1.3 - Renewable Energy Systems

Paper Number: 118125

118125 - Techno-Economic Analysis of Wind- and Solar-Based Steel Production 

Primary steel production involves the use of iron ore and heavily relies on fossil resources as heat sources and for the reduction of iron ore. As a result of this reliance on fossil fuels, iron and steelmaking accounts for 8% of global energy demand, making it responsible for 7% of the energy sector’s carbon dioxide emissions. A recent evaluation of the steel industry by the International Energy Agency (IEA) recommends new low-emission technologies based on hydrogen to lower the industry’s emission profile. Using hydrogen to directly reduce iron oxide to metallic iron has been successfully demonstrated with no negative effects on steel quality. As hydrogen can be produced from renewables, such as wind and solar, this provides an opportunity to reduce the reliance on fossil resources and to decarbonize the steel industry. Despite the promise, there remains little guidance on the economic impact of transitioning from fossil resources to hydrogen for the production of green steel.

Here, we present a techno-economic analysis of a 1 million tonne per year steel mill using green hydrogen-based direct reduced iron (DRI). We provide insights into plausible process configurations where the DRI process is integrated with an electric arc furnace. Detailed insights into carbon dioxide emission sources are presented with breakdowns of direct and indirect emissions. Moreover, the levelized cost of steel is estimated and cost driving factors are identified. The results of the hydrogen-based DRI process are compared to a state-of-the-art natural gas-based DRI process to derive the breakeven cost of hydrogen that is needed to make green hydrogen-based steelmaking cost competitive. We consider local hydrogen generation by way of wind- and solar-powered electrolysis at a scale of 200 tonnes of hydrogen per day. To address the issue of intermittent power supply, several storage technologies are evaluated including salt caverns, cryogenic liquid, compressed gas, and methylcyclohexane (MCH), a liquid organic hydrogen carrier. Liquid organic hydrogen carriers are a promising hydrogen storage technology that is geographically agnostic and can store hydrogen in liquid form at ambient temperature and pressure. In order to ensure the continuous supply of hydrogen to the steel facility at the lowest possible cost, the storage and electrolyzer capacities are carefully optimized based on the specific capacity factors of wind and solar. Based on rigorous process modeling and economic evaluations of the steel mill, we derive estimates for storage duration, storage cost, energy density, charge/discharge rates and efficiency, which are further used to establish technical requirements and performance targets.

Presenting Author: Fabian Rosner Lawrence Berkeley National Laboratory

Presenting Author Biography: Dr. Fabian Rosner is a Postdoctoral Fellow in the Sustainable Energy Systems Group at Lawrence Berkeley National Laboratory (LBNL). Fabian’s research focuses on techno-economic and life-cycle analyses of sustainable energy systems. In his research, he uses computational methods and process models to identify environmental and economic opportunities for green technologies. Fabian has applied his modeling techniques to a wide range of research questions to support R&D efforts as well as to guide policy decisions. Over the years, he worked on an array of advanced electricity generation technologies, electro-chemical energy conversion processes, carbon capture and utilization systems, and the water energy nexus.
Prior to his current position at LBNL, Fabian received his Ph.D. and M.S. in Mechanical and Aerospace Engineering from the University of California, Irvine, with specialization in the thermal sciences and he received a M.S and B.S. in Chemical Engineering from the Technical University of Munich in Germany, with a specialization in chemical process engineering.