Investigations of reduction kinetics continued to build a high-quality kinetic database for H2-based DR for calibration of models and tools under development. Two complementary kinetic sub-models were developed and tested, in particular a Single Pellet Kinetic Model (SPKM). Improvements and updates were carried out to refine models capabilities and results.
Metallurgical tests were carried out in the DR Simulator testing facility under high H2 enrichment to evaluate the reduction behaviour of considered pellets. Additional tests showed different pellet degradation behaviours at different elevated temperatures and fines generation in post-reduction mechanical degradation tests. It was observed that increased pellet reduction reaction during tests leads to developing progressively deeper cracks.
The rotational shear test device for measuring adhesive forces of pellet bulks in a H2-rich atmosphere at high temperature and shear was constructed. Its operability was validated, and tests were carried out to verify its usability and functioning: some modifications compared to the initial design were necessary. A testing protocol was implemented, and different samples were investigated.
A DEM-based tool was developed to simulate mechanical interactions between the particles and simulations were conducted. The updated SPKM was implemented via Finite Element Method (FEM), Discrete Element Method/Computational Fluid Dynamics (DEM/CFD) and Finite Volume Method (FVM) simulation. Dedicated simulations demonstrate the successful integration.
Tests were carried out to determine the gas permeability of different materials. Firstly, a tubular device was used, then experiments were done in the Midrex-based demonstrator. It was also used to determine pressure drop and particle movements for the DR furnaces models, e.g the DEM/CFD model simulating the interaction between fluid and bulk solids. The simulation generally matches experimental data with some deviations on pressure drops. The DEM-CFD model for granular particle movement and gas flow was validated. The FEM model was updated by further calibrating the rheology model based on the apparent viscosity to optimise the simulation of solid flow. Finally, the results of models and trials were compared to complete the validation work to provide the “hybrid demonstrator” for DR shaft furnace scale-up and optimisation.
Several modelling and IT work was carried out to revise the multipurpose simulation toolkit to simulate the overall-production chain during transition scenarios: gas and energy network. Some AML models, and IT procedures to manage data exchange, convergences, demands, scenarios, etc. were updated. New models of new process units for transition scenarios were developed: Models were developed in Aspen Plus representing both Midrex+H2 and Energiron Zero Reformer processes in all stages, and in AML language. An EAF model was developed in IRMA. Discussion was done with an advisory board member to obtain data to update one of the DRI process models. The AML system optimization model was used in exemplar analyses to illustrate model applications and to evaluate test cases; together with first LCA analyses it highlights the high influence of grid electricity costs and emission intensities to allow the transition to hydrogen-based steelmaking. A list of scenarios to be simulated with the IRMA-Aspen Plus combined tool was elaborated.
An intensive dissemination work was carried out by the consortium through participation to international scientific events and publications of scientific papers. Connections with other related EU-funded projects were established. The consortium applied for the Net-zero industries Award 2024 and was awarded as a national winner for Germany.
