Steel production continues to be the most impactful industrial sector in our economy in terms of carbon emissions. The main difference compared to just a couple of years ago is that now, a plethora of new renewable hydrogen projects have been announced across the world by both private and public consortia (link). The industry interest towards novel decarbonization technologies and feasibility studies has skyrocketed and the low carbon steel community is rapidly growing.
UC Irvine’s Advanced Power and Energy Program is leading a Department of Energy (DOE) HySteel project to use an integrated high temperature Solid Oxide Electrolysis Cells (SOEC) system to produce renewable hydrogen that can be used to convert raw iron ore (Fe2O3) into iron (Fe) through a process called hydrogen direct reduced iron (HDR). This reaction only produces water as a by-product, allowing for the complete elimination of CO2 emissions from the ironmaking process. The team expects that the SOEC thermal and electrochemical integration with the DRI system will reduce the primary energy consumption and CO2 emissions by more than 30% and 40%, respectively.
The project is now at its first year mark and it has theoretically shown the possibility of producing hot iron at 0.8% carbon content and >97.5% metallization with a primary energy consumption of 8.0-8.8 GJ/tDRI and with CO2 emissions ranging from 15 to 97 kgCO2/tDRI. This contrasts with a typical natural gas-based DRI system and a blast furnace-basic oxygen furnace route performing 10.1 GJ/tDRI and 19-20 GJ/tcrude steel, and 442 kgCO2/tDRI and 1.8-1.9 tCO2/tcrude steel, respectively.
The team has also modelled the unique capability of SOEC to operate with mixtures of steam and CO2 to produce a renewable carbon-based syngas, which can be used as a reducing gas in the shaft furnace instead of natural gas. This configuration allows for a shorter-term transition from a state-of-the-art natural gas-based technology to a low-carbon renewable process. The SOEC can operate in so-called co-electrolysis mode, simultaneously converting H2O and CO2 into H2, CO, and CH4.
The project is now at the design phase for the laboratory-scale demonstration unit, which will integrate an SOEC module with a simulated HDR furnace using a “Hardware-In-the-Loop” concept. The 10 Nm3/day hydrogen production capacity SOEC unit will be manufactured and installed at the FuelCell Energy site in Danbury, Connecticut, which will experimentally prove: i) hydrogen production efficiencies of pressurized and thermally integrated SOECs <35 kWhel/kg; ii) system integration of SOEC and HDR units to measure primary energy consumptions <8 GJ/tonDRI and and CO2 emissions <50 kgCO2/tDRI.
The UCI APEP HySteel team – comprised of the largest U.S. manufacturer of Solid Oxide Electrolysis systems; FuelCell Energy; the engineering consulting firm, Hatch; the two international academic and tech-transfer institutions, Politecnico di Milano and LEAP; and Southern California Gas Company (SoCalGas) – continue working together with DOE support to ensure the industrial relevance of the demonstration proposed in the project. The team is in continuous communication with its Advisory Board members, now counting some of the majors U.S.-based and international steel manufacturers, namely Arcelor Mittal, Nucor Corporation, Tenova, and Midrex, as well as the major European gas transmission operator Snam. Additional Advisors are welcome to join the project to broaden the relevance of the project’s outcomes throughout the steel industry. Similarly, the team is looking for possible industrial partners interested in deploying a containerized SOEC module at a DRI plant during phase two of the project.
Refer to the official HySteel website: http://www.apep.uci.edu/H2GS/