The main project objectives (MOs), as summarized in the proposal and address the whole value chain.
Hence, the first main objective (MO1) of the project has been the integration of waste biomass in the reduction stage originating from the chemical looping process (MO1). The underlying idea is that biomass (carbon-neutral) is oxidized through reduction–oxidation reactions with the iron ore. This benefits the downstream process, as the iron ore is preheated and already partially reduced to the magnetite state, while in some cases reduction to wüstite has also been observed.
The second objective (MO2: Development of four hydrogen based innovative processes for the reduction process) has been pursued at lab scale through four low-CO2 ironmaking routes: pressurized fluidized bed reactor (PFBR), rotary kiln hydrogen reduction, mechanochemical activation of hematite ores, and hydrogen plasma smelting reduction (HPSR). These hydrogen-based approaches, combined with ore pre-treatment and process intensification, aim to enable efficient decarbonised ironmaking routes. Overall, the results validate key concepts for hydrogen-based ironmaking and support further optimisation and scale-up. Together, MO1 and MO2 cover the steelmaking flowsheet up to iron production; however, for DRI-based routes an Electric Arc Furnace (EAF) is still required, where biocarbon can support slag foaming and promote carburisation to facilitate melting.
This leads to MO3 (MO3: Integrate carbon residues in the EAF smelting process for reduction of the CO2 emissions), which focuses on lab- and pilot-scale slag foaming using biochar and on assessing slag foaming behaviour in the HPSR route, which represents a single-step process without prior direct reduction. Foaming experiments with selected biochars have already been carried out during the reporting period, and first HPSR trials using biochar have been performed, with further optimisation ongoing.
Within the next objective (MO4: Delivery of a low carbon-emission technology for steel forming and shaping), downstream decarbonisation aspects are addressed, with a focus on low-emission technologies for steel forming and shaping. A commercial operating furnace was used as a baseline to establish reference conditions in terms of energy consumption and CO2 emissions. This analysis, completed during the reporting period, provides the foundation for defining the current state of the art. Decarbonisation solutions are being developed, including a reheating system for steel based on thermal power from a plasma torch, while enabling the combustion of hydrogen-rich plasma gas. In addition, fully electrical approaches are being investigated, including heating and annealing based on conduction and induction of steel slabs.
Moreover, Objective MO5 (Development of a Digital Twin application for AI-based steel quality monitoring) has been addressed in a highly dynamic and innovative manner. In-operando and advanced characterization of iron ore reduction processes is being developed, supported by feasibility studies and simulations that have enabled experimental strategies based on synchrotron tomography, neutron diffraction, and Bragg-edge radiography.
To assess system-wide impact, MO6 (Evaluate the carbon reduction and sustainability of the process through the application of Life Cycle Analysis, Life Cycle Cost Analysis and environmental assessment) and MO7 (Establishing partnerships between steel producers, market analysis and development of a business plan) address sustainability and exploitation. Market analysis highlights pressure on the European steel sector from energy costs, geopolitics, and declining demand, alongside growing demand for low-carbon steel driven by CBAM, ETS reform, and hydrogen availability. LCIs for MIDREX and BF-BOF routes were developed with a harmonised SimaPro template. A SWOT analysis, Business Model Canvas, and financial framework support commercialization across industry, academia, and ore suppliers.
Finally, MO8 (Maximize impact through wide dissemination and communication means and valorise knowledge and results from ZEROSTEEL project) focuses on dissemination and communication. A project website and LinkedIn presence have been established, and public outreach activities such as “Lange Nacht der Forschung” in Vienna have been conducted, targeting the general public and students. Publication activities have been initiated, primarily through conference contributions, with journal publications and expanded workshop engagement planned for the next reporting period.
