The urgent need for the decarbonization of steel metallurgy in the face of climate change causes a paradigm shift, eventually leading to a transformation of well-established industry processes. This transformation, for example towards a clean hydrogen-based direct reduction of iron, requires knowledge about the interdependencies of all process parameters, something that physically-sound process modelling can offer.

We show how the combined use of thermodynamic and kinetic process modelling can simulate heat and mass transport in an industrial shaft furnace with iron oxide pellets exposed to a reducing gas stream. To achieve this, we scale up a one-dimensional pellet micro model taking into account kinetics and thermodynamics of the reduction and gas-gas reactions, heat transfer and diffusion.

Our approach enables the integration and optimization of specific input parameters, such as kinetic parameters, properties of the iron oxide pellets, and gas input streams, and hence supports finding pathways to the decarbonization of the steel industry.