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DOE OSTI · 3023522

A percolating path to green iron

Paul, Subhechchha [Stanford Univ., CA (United States); SLAC National Accelerator Laboratory (SLAC), Menlo Park, CA (United States)]·Kanesalingam, Brinthan [SLAC National Accelerator Laboratory (SLAC), Menlo Park, CA (United States); Stanford Univ., CA (United States)]·Ma, Yan [Delft Univ. of Technology (Netherlands); Max Planck Institute for Sustainable Materials, Dusseldorf (Germany)]·Villanova, Julie [European Synchrotron Radiation Facility (ESRF), Grenoble (France)]·Requena, Guillermo [German Aerospace Center (DLR), Cologne (Germany); RWTH Aachen Univ. (Germany)]·Akpu, Stanley Chidubem [Nnamdi Azikiwe Univ., Awka (Nigeria)]·Raabe, Dierk [Max Planck Institute for Sustainable Materials, Dusseldorf (Germany)]·Battiato, Ilenia [Stanford Univ., CA (United States)]·Dresselhaus-Marais, Leora [Stanford Univ., CA (United States); SLAC National Accelerator Laboratory (SLAC), Menlo Park, CA (United States)] (ORCID:0000000207570159)
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Abstract

About 1.9 gigatons of steel is produced every year, emitting 8% (3.6 gigatons) of global CO 2 in the process. More than 50% of the CO 2 emissions come from a single step of steel production, known as ironmaking. Hydrogen- based direct reduction (HyDR) of iron oxide to iron has emerged as an emission-free ironmaking alternative. However, multiple physical and chemical phenomena ranging from nanometers to meters inside HyDR reactors alter the microstructure and pore networks in iron oxide pellets, in ways that resist gaseous transport of H 2 /H 2 O, slow reaction rates, and disrupt continuous reactor operation. Using synchrotron nano X-ray computed tomography and percolation theory, we quantify the evolution of pores in iron oxide pellets and demonstrate how nanoscale pore connectivity influences micro- and macroscale flow properties such as permeability, diffusivity, and tortuosity. Our modeling framework connects disparate scales and offers opportunities to accelerate HyDR.

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Paul, Subhechchha [Stanford Univ., CA (United States); SLAC National Accelerator Laboratory (SLAC), Menlo Park, CA (United States)], Kanesalingam, Brinthan [SLAC National Accelerator Laboratory (SLAC), Menlo Park, CA (United States); Stanford Univ., CA (United States)], Ma, Yan [Delft Univ. of Technology (Netherlands); Max Planck Institute for Sustainable Materials, Dusseldorf (Germany)], Villanova, Julie [European Synchrotron Radiation Facility (ESRF), Grenoble (France)], Requena, Guillermo [German Aerospace Center (DLR), Cologne (Germany); RWTH Aachen Univ. (Germany)], Akpu, Stanley Chidubem [Nnamdi Azikiwe Univ., Awka (Nigeria)], Raabe, Dierk [Max Planck Institute for Sustainable Materials, Dusseldorf (Germany)], Battiato, Ilenia [Stanford Univ., CA (United States)], Dresselhaus-Marais, Leora [Stanford Univ., CA (United States); SLAC National Accelerator Laboratory (SLAC), Menlo Park, CA (United States)] (ORCID:0000000207570159). 2025-08-05. A percolating path to green iron. https://doi.org/10.1016/j.xcrp.2025.102729

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