Fossil-free combustion in grate-kiln pelletizing plants using co-jet burner


Sofia Larsson




Purpose and goal

The aim of the project is to investigate the possibility of replacing fossil fuels with hydrogen in LKAB´s kiln, where the challenge lies in achieving a long, evenly hot flame. The properties of the hydrogen flame are controlled by the mixing between fuel and oxygen and a long flame requires a high inlet speed combined with slow mixing. The task is complicated by large amounts of hot process gas, which results in a flow field with a significant impact on the mixing process. The goal is to develop techniques for controlling the properties of the gas flame through a so-called co-jet burner.

Expected results and effects

Replacement of fossil fuels in the iron ore pelletizing process is required for carbon-free steel production. The feasibility of fully replacing coal with hydrogen in the kiln using a co-jet burner solution will be evaluated. The results include fluid mechanical simulation and experimental models where the most important challenges regarding momentum, heat, and mass transfer when changing fuel in the kiln can be identified and solutions tested. If the technology is deemed feasible, a concept ready for testing in LKAB´s pilot-scale kiln will be developed at the end of the project.

Planned approach and implementation

The project involves both simulations and experiments and is divided into four work packages: WP1 – Project coordination, WP2 – Cold flow simulations, WP3 – Cold flow validation experiments, WP4 – Combustion simulations.